Combustion Visualization of a Supercharged Direct Injection Hydrogen Engine

Kyohei IZUMI (Kawasaki Motors)･Toshitaka FUJIKI (Yamaha Motor)･Yusuke MARUI (Honda Motor)･Yoshinari NINOMIYA (Suzuki Motor)･Kazuki ARIMA･Hiroshi KATO･Taketo MARUBASHI･Yusaku MATSUMOTO･Satoaki ICHI (Kawasaki Motors)

Abnormal combustion that includes preignition and knocking is a big issue in the development of the hydrogen engine for carbon neutrality .
Thus, it is necessary to clarify the peculiar combustion mechanism of hydrogen with visualization.
In this paper, we tried combustion visualization with our supercharged direct injection hydrogen test engine.

Comparison of exhaust NOx, etc. between direct-injection hydrogen engines and intake port injection hydrogen engines

Tomohiko Kamio･Atsushi Yamamoku (Yamaha Motor)･Koichiro Matsushita (Honda)･Kyohei Izumi (Kawasaki Motors)･Yuta Kagawa (Suzuki Motor)

A single-cylinder hydrogen fueled engine was used to compare differences in Nox emissions between port fuel injection (PFI) and direct injection (DI).
NOx emissions in DI varied over a wide range depending on excess air ratio, while PFI produced relatively consistent NOx emissions regardless of engine conditions.
We theorize that this behavior is due to relatively inhomogeneous air-fuel mixing in the case of DI.

Investigation of Effect of Hydrogen Mixture Formation on Hydrogen Combustion by Hydrogen Jet Model

Atsushi Hisano･Yota Sakurai･Masahito Saito (Kawasaki Heavy Industries)･Satoaki Ichi (Kawasaki Motors)

In a hydrogen direct injection engine, the mixing state of hydrogen and air in the cylinder is an important factor to ensure combustion stability. An injector analysis model was constructed from the results of visualization of a hydrogen injection jet using the schlieren method. The effect of injection timing on hydrogen combustion is examined by in-cylinder analysis using the injector analysis model.

Near-infrared two-color pyrometry and numerical investigation on combustion processes of premixed hydrogen-air mixtures in a rapid compression machine

Fangsi Ren･Haoming Gu･Daisuke Kaminuma･Shinji Nakaya･Mitsuhiro Tsue (the University of Tokyo)･Satoaki Ichi (Kawasaki Motors, Ltd.)･Koichiro Matsushita (Honda Motor)･Kishal Saxena (Yamaha Motor)･Yoshinari Ninomiya (Suzuki Motor)

Hydrogen is a promising carbon-neutral alternative fuel for internal combustion engines. In this study, combustion tests of lean and stoichiometric hydrogen-air mixtures were conducted using a rapid compression machine. Flame temperature distribution during the combustion process was measured using high-speed cameras and near-infrared two-color pyrometry. Furthermore, numerical simulations of the combustion process were performed, and the results were compared and validated against experimental data.

Effect of Air Excess Ratio and Engine speed on Instantaneous Heat Flux in Motorcycle Hydrogen Engines

Masakuni Oikawa･Aoshi Yokomori･Yuji Mihara･Yuki Kaga･Takumi Iwata (Tokyo City University)･Tomohiko Kamio･Atsushi Yamamoku (Yamaha Motor)･Kenichi Sano (Honda Motor)･Yoshinari Ninomiya (Suzuki Motor Co., Ltd.)･Michiyasu Owashi (MOTORA,Inc.)

A prototype instantaneous heat flux sensor was attached to the cylinder head of the 125cc motorcycle hydrogen engine with a small displacement and large S/V, and the effects of air excess ratio and rotational speed on the heat flux were confirmed. As a result, the maximum value of instantaneous heat flux increased significantly when the air excess ratio was changed from 2.2 to 1.6 and the engine speed was changed from 3000 rpm to 8000 rpm.

Development of A λ=1 Turbocharged Direct Injection Hydrogen Engine

Kenjiro Nakama･Kei Yoshimura･Naoto Watanabe･Yutaro Usui (Suzuki Motor)･Kapus Philipp･Poetscher Peter･Kapus Paul (AVL List)

A turbocharged direct injection hydrogen engine, offering power performance equivalent to gasoline, was developed, and evaluated both on test benches and in vehicles. This engine features λ=1 combustion and possesses durability and emissions performance comparable to mass-produced gasoline engines. Vehicle testing clearly demonstrated its ability to meet the latest emissions regulations.

Commercial Hydrogen Engines: Methodologies for rapid mechanical development and validation

Anton Arnberger･Gottfried Lurf (AVL List)･Peter Grabner･Michael Schneider (Technical University Graz)

Hydrogen engine development faces critical challenges to ensure robust and reliable performance in real-world applications. Adequate lube oil selection is key, as it influences combustion stability and long-term engine performance. An advanced lube oil screening method allows early-stage testing of long-term effects, such as increased oil consumption due to wear. Optimizing oil formulations and engine boundary conditions for controlled pre-ignition can offer significant benefits. Additionally, managing high water condensation in the crankcase under low load and cold conditions necessitates a thorough evaluation of ventilation systems and oil strategies. AVL's water accumulation testing provides an effective method for rapid evaluation and optimization.

Hydrogen Combustion Engine : Performance, Fuel Efficiency and Emissions optimisation

Joel Op de Beeck･Badr-Din Lahmoumi･Jezer Costa･Krzysztof Potaczek･Marcos Carvalho-Barreto･Nissrine Harbil･Toshihiko Minami (OPmobility)

The hydrogen internal combustion engine has the potential to bring down the CO2 emissions to zero. The NOx emissions from the engine need to be kept under control to meeting emission regulations. The engine needs to be protected from pre-ignition, whilst maintaining maximum power. Engine efficiency is key to assure range. This study will compare/combine hydrogen combustion with water injection and aftertreatment to find an optimal solution.

Study on Gas-Liquid Two-Phase Flow Injection System of Hydrogen and Water for Suppression of Abnormal Combustion in Spark Ignition Hydrogen Engine

Taichi Hiyoshi･Eriko Matsumura･Jiro Senda (Doshisha Univ.)･Keiso Takeda (enable)

Hydrogen does not emit CO2 during combustion, but abnormal combustion is a problem. Therefore, it is necessary to control abnormal combustion. In this paper, we focus on the method of injecting water at the same time as hydrogen injection and fabricate an injector that injects hydrogen in a two-phase flow state with water. Helium was used as a substitute for hydrogen. This paper reports the results of an analysis of the spray characteristics of this injector.

Effects of High Injection Rate on Thermal Efficiency in Low-Pressure Direct Injection Hydrogen Engines

Seiya Yamada (Tokyo City University)･Nobuhiro Shimmura (Kawasaki Heavy Industries Ltd.)･Masakuni Oikawa･Kotaro Hata (Tokyo City University)･Sekai Miyamoto (Kawasaki Heavy Industries Ltd.)･Yuji Mihara･Yasuo Takagi (Tokyo City University)

In the previous report it was shown that lowering the hydrogen injection pressure maintained the thermal efficiency level, but it was revealed that an increase in NOx emissions should be caused by longer injection duration. In this study, an injector with a high injection rate was used and effectively suppressed NOx emissions in addition to improving thermal efficiency, achieving a high indicated thermal efficiency close to 50%.

Effect of unsteady flow field on spray feature in a DISI engine

Tomohiro Ishiguro･shota Minami･Eriko Matsumura･Jirou Senda (Doshisha University)･Shigenori Haraguchi･Yoshihisa Sato (Honda Motor)

In a DISI engine, fuel deposition on the wall is a factor in the formation of PM. In this study, the velocity distribution of the in-cylinder flow field was analyzed using a rapid compression and expansion machine and the spray features during the formation process of spray injected into an unsteady tumble flow field were analyzed by changing the injection pressure and injection timing as parameters.

Development of a Prediction Model of Soot Particle Size Distribution applicable for Design Calculations of Internal Combustion Engines (3rd Report)
-Validation for 5-Component Gasoline Surrogate-

Jun Hashimoto (Oita University)･Kazumasa Ito (Graduate School of Engineering, Oita University)･Tatsuya Kuboyama (Graduate School of Engineering, Chiba University)･Yasuyuki Sakai (Carbon Recycling Energy Research Center, Ibaraki University)･Kazuhiro Akihama (Nihon University)

In previous work, we have proposed a soot prediction model which can predict the soot particle size distribution and is applicable to design calculations of internal combustion engines. The model was validated for experimental results measured by using burner stabilized stagnation flames and a DISI engine for iso-octane/n-heptane/toluene blended fuels. In this study, the model was extended to a 5-component gasoline surrogate, which is composed of iso-octane/n-heptane/toluene/iso-pentane/Trimethylbenzene and reproduces the sooting characteristics of gasoline, and validated against the experimental results of a DISI engine.

Design and simulation of ignition-compression combustion system for gasoline engine

Cong Yao･Wenxin Cai･Yang Song･Gen Chen (Dong Feng Motor)

This article proposes the combustion concept of ignition-compression combustion in principle, and studies it from the aspects of intake port, combustion chamber, piston surface shape, etc. the best ignition-compression combustion system can achieve three-stage heat release in time and zone: Turbulent flame --> Jet flame --> Gentle spontaneous combustion. Then, the influence of boundary simulation analysis on ignition-compression combustion efficiency is analyzed separately from environmental temperature, intake air pressure, ignition advance angle, injection strategy, fuel type, and other factors. The simulation results show that the indicated thermal efficiency of gasoline engine can be 46.9%.

Experimental study of gasoline engine on the test-bench base on SICI combustion model

Wenxin Cai･Cong Yao･Gen Chen･Yang Song (Dong Feng Motor)

This article is based on a new ignition-compression combustion mode, the ignition-compression combustion system was redesigned, and a new ignition-compression combustion mode was verified on the bench. The experimental results showed that the 2 times fuel injection strategy was more suitable for the ignition-compression combustion mode; The timing of secondary injection and excess air coefficient for achieving optimal thermal efficiency are different at different operating points with different speeds and loads; After blending ethanol into fuel, the hydrogen to carbon ratio increases, the fuel's oxidizing properties are enhanced, and the levels of THC, CO, and CO2 emissions decrease.

Comparison of Various Computational Methods for Gear Stirring (2nd Report)
-Discussion of prediction accuracy for droplets and proposal of a practical method for improvement-

Takafumi Kawamura (Computational Fluid Dynamics Consulting)･Masaru Shimada (JATCO Engineering)･Tadashi Yamada (Toyota Motor)･Masanori Katou (Honda R&D)･Daiki Saegusa (Honda Motor)･Akira Nakashima (Mazda)･Tomoaki Watamura (University of Tokyo)･Kazuyasu Sugiyama (Osaka University)

In the first report, experimental results for air-oil two-phase flow driven by gears were compared with computations using various methods including particle method, lattice Boltzmann method, finite difference method and finite volume method. In this report, influence of spatial resolution and its relation to surface tension on the prediction accuracy are discussed, and then a practical method is proposed for improving accuracy.

A Study on High Rotational Speed Traction Drive
-High Reduction Ratio Experiment and Unit Configuration-

Yuechen Jia･Takeshi Yamamoto (Tokai University)

With the aim of miniaturization, the trend toward higher rotational speeds of drive motors has advanced, requiring high reduction ratios for the reduction drive. Traction rollers are considered capable of achieving higher reduction ratios than gears, but their performance and limitations remain unclear. Therefore, in the present study, a high-speed test machine with a high reduction ratio was designed and manufactured, and the traction coefficient and transmission efficiency were measured. The results indicated that increasing the reduction ratio from 2.5 to 6 did not lead to any performance degradation.

Emission and system cost reduction by means of bearing friction optimization

Seiya Nishizawa (Schaeffler Japan)･Franz Voelkel (Schaeffler Technologies AG & Co. KG)

Bearing losses add up to a significant share of overall vehicle power losses. On the one side, this influences the downstream emissions, on the other side a BEV’s upstream emissions are heavily affected well as a certain capacity of the battery is only needed to feed these losses. Every piece of energy which is not lost to friction doesn’t have to be stored in an battery.
This lecture discloses the hidden potentials in mechanical power loss reduction, especially for bearings, by means of power density increase, on-the-point optimization and drag loss minimization. The effectiveness of friction improvement relative to on-costs for the measures will be shown in addition.

Electrified Motorcycle Powertrains - Hybrid Concepts Paving the Way to Future Technologies

Wolfgang Johann Schoeffmann･Christian Hubmann･Gernot Fuckar･Christian Martin (AVL List)

Electrification of two-wheelers faces unique challenges, including packaging and mass constraints, limited urban charging infrastructure and stringent cost targets.
Battery electric two wheelers are ideal for city driving whereas hybridization extends operational limits, enabling electric modes for zero-emission driving, while boosting enhances performance and transient response.
An electrified variable power-split hybrid scooter powertrain combines efficiency improvements and electric driving whereas an integral dedicated hybrid transmission is specified for a performance hybrid with minimized mass and packaging.
The paper covers layout criteria for ICE and hybrid system, while addressing operation modes in the relevant drive cycle sections.

Study of Increase in Drag Torque at High Rotational Speed of Wet Multi-plate Clutch Part3．

Hirofumi Ebisumoto･Hitoshi Tamegai･Tomohiro Yoshizue (Mazda)

This report describes the drag characteristics of wet multi-plate clutch in automatic transmission when they are released. The drag torque of the clutch may increase at high rotational speed. At that time, plate vibration may be seen, which is considered to be the cause of the increase in drag torque. We modeled this plate vibration by coupled CFD and vibration analysis. And measured the vibration with a high-speed camera and verified the model. Thereby, the vibration mechanism was clarified.

Electrical Pitting Prevention Design for Bearing on Motor

Takahiro Kuwabara･Satoshi Takemoto (Nissan Motor)

Electrical pitting has been occurred on the torque transmission path incoming electric current due to the electrification, and is expected to be apparent in the future. While developing countermeasure solution either isolation or conductive items for electrical pitting, these measures are conducted either a certain period of maintenance or after noticing defect on testing. Prevention design for electrical pitting on bearing aiming optimal design from early stage of design study was developed.

Influence of Speed Ratio on Nominal Slip Ratio between Pulleys of Metal Pushing V-belt Type CVT under Steady-state
-―Changes of Pitch Angle of Element and Belt Path―-

Ryota Matsuda (Graduate School of Doshisha University)･Kazuya Okubo･Kiyotaka Obunai (Doshisha University)

The objective of this study was to investigate the influence of speed ratio on slip ratio between pulleys of metal pushing V-belt type CVT under steady-state. Relative pitch angel was calculated with referring to the data of acceleration measured by a 3-axis acceleration sensor attached to the element. Revolution speeds of the driving and driven pulley were measured by the rotational speed sensors. The nominal slip ratio defined as the difference between revolution speeds of two pulleys was increased due to increasing absolute relative pitch angle.

Investigation of the Impact of Factors on Abnormal Austenite Grain Growth in Carburized Drive System Components

Yasuo Itou･Gou Katou (JATCO)

Carburized components formed by cold forging can sometimes exhibit abnormal austenite grain growth, which leads to a decrease in strength. Although the influencing factors are qualitatively known, their degree of impact is not clear. Therefore, using test specimens that simulate the component manufacturing process, we experimentally clarified the relationship between each influencing factor and the austenite grain size after carburization.

Prediction of Abnormal Grain Growth in Drivetrain Carburized Components Using Bayesian Networks

Akira Mizuno･Gou Katou･Makoto Maeda (JATCO)･Shuhei Kojima･Tsubasa Yamashita･Takumi Yoshida (MI-6)･Junya Inoue (The University of Tokyo)

Abnormal grain growth, which leads to a decrease in the strength of drivetrain carburized components, is a complex phenomenon that makes its occurrence difficult to predict. In this study, we developed a method to predict the occurrence of abnormal grain growth by constructing a Bayesian network and training it using test piece data that simulates cold forging, based on the material properties and manufacturing conditions.

Infrared High-Speed Thermography of Piston Surface on Diesel Engine

Kazuya Miyashita･Shinya Furukawa･Yoshinori Ishii･Hisashi Ozawa (Isuzu Advanced Engineering Center)

Combustion CFD reproduces in-cylinder combustion by combining models representing each phenomenon. However, there are issues with the accuracy of these models, in particular, verification of wall heat loss is necessary. In this study, in order to verify the accuracy of wall heat loss model, measurement of wall surface temperature distribution was attempted in a top-view optical engine. Infrared radiation from the piston surface impinged diesel spray flame was directly visualized by using the high-speed infrared camera. The obtained infrared images showed the potential for high-speed measurement of wall surface temperature distribution.

NOx Reduction Strategy Using Direct Water Injection in a Diesel Engine (Second Report)
-pplying the In-Cylinder Water Stratification Concept to Higher Load Conditions-

Kazuhisa Inagaki (TOYOTA CENTRAL R&D LABS)･Tsutomu Kawae (TOYOTA INDUSTRIES CORPORATION)･Teruaki Kondo･Kazuaki Nishikawa (TOYOTA CENTRAL R&D LABS)

We proposed a combustion concept that significantly reduces NOx emissions by stratifying water within the engine cylinder. In this second report, engine performance was evaluated under higher load conditions with an IMEP of 1.2 MPa. It was demonstrated that, under conditions where the water injection volume was 50% of the fuel amount, optimizing the division of water injection, injection timing, and intervals resulted in approximately a 40% reduction in NOx at equivalent soot concentration levels.

Thermal Efficiency Improvement for a High-compression-ratio HD Diesel Engine by Utilizing an Offset Orifice Nozzle

Tomoyuki Mukayama･Noboru Uchida (New A.C.E Institute)

It has been necessary to investigate into thermal efficiency improvement and fuel spray characteristics aiming to achieve it for commercial heavy-duty diesel engines. This study focuses on the simultaneous improvement in cooling loss and indicated thermal efficiency by means of an offset orifice nozzle presented in the former study, and investigates further into combustion and emission characteristics of a high-compression-ratio heavy-duty diesel engine equipped with offset orifice nozzles. Internal nozzle flow analysis by numerical simulation and in-cylinder combustion visualization were also carried out to identify the cause of significantly different combustion phenomena.

Model analysis of the concentration distribution in the spray and wall interference in high compression ratios (high ambient density field) in diesel engines

Ryoto Yoshikawa･Yuki Yasuno･Eriko Matsumura･Jiro Senda (Doshisha Univ.)

Increasing the compression ratio in diesel engines improves thermal efficiency. However, the higher gas density in the cylinder changes the flame wall impingement pattern and affects the cooling loss, so the combustion chamber shape must be optimized. In this study, the combustion chamber shape for heavy duty vehicle diesel engine is optimized by model analysis.

Modeling of Fuel Spray-Wall coated Lubricating oil Interference in Compression Ignition Engines

Yuki Nakata･Shoto Nakaoka･Kanako Nishimura･Eriko matumura (Doshisha Univ.)

Oil dilution during post-injection is a problem in compression ignition engines. However, existing models cannot adequately account for the impingement of fuel droplets on wall coated with lubricating oil film. In this study, authors developed new spray impingement model that considers impingement of fuel droplets and lubricant oil film. In addition, the applicability of the model was verified through experimental results and comparisons with other models.

Evaluation on the Exhaust Behavior of a Diesel Light Duty Vehicle by On-Board Alternative Analyzers.

Noritsune Kawaharada･Hisakazu Suzuki (NALTEC)

The target substances in the Real Driving Emission (RDE) test are mainly CO2 and NOx. Additionally, due to its high global warming potential, N2O is also a focus in this study. Alternative measurement principle analyzers, different from the commonly used non-dispersive infrared (NDIR), non-dispersive ultraviolet (NDUV), and chemiluminescence detection (CLD) methods, were applied for the measurement of diesel light-duty vehicle emissions. The exhaust behavior of the diesel light-duty vehicle has been evaluated under several temperature conditions, and the variance in the emission results from the different measurement principles has been discussed.

Reduction mechanism of NOx derived from post injection

Yukito Watanabe (YANMAR Holdings)･Yoji Hiraiwa (Hokkaido University Graduate School of Engineering)･Gen Shibata･Hideyuki Ogawa (Hokkaido university Research faculty of engineering)

It has been reported that post-injection in diesel engines has a NOx reduction effect, but the detailed mechanism remains unclear. In this study, the NOx reduction effect of post-injection was investigated in detail through engine experiments, and the potential for NOx reduction by ammonia generated during combustion was analyzed using zero-dimensional chemical kinetics calculations.

Estimation of Gas Temperature in Intake System of a Diesel Engine Using Modeling Method Based on Machine Learning

Takato Ikedo･Yoshifumi Wakisaka (Toyota Central R&D Labs.)

This report proposes a model to estimate gas temperature in intake system of a diesel engine with high accuracy for the purpose of improving fuel consumption and reducing emissions by optimizing the control of diesel engine. The proposed model combines neural network and physics, and it is based on the energy conservation law and the mass conservation law in order　to estimate gas temperature in intake system. As a result of evaluating the estimation accuracy for the test data created using virtual diesel engine data, the mean absolute error in all sections was 0.692 degC.

Proof of advanced emission control systems and thermal strategies for future NRMM regulations

Bernhard Raser (AVL List)･Joachim Demuynck･Dirk Bosteels (AECC)･Hannes Noll (AVL List)

The regulation of pollutant emissions for Non-Road Mobile Machinery is under review in the US (CARB Tier 5 proposal) and EU (Stage V review). Future regulations are expected to emphasize diverse operating conditions, including continuous low load. CO2-neutral fuels are being explored to mitigate the carbon footprint of NRMM Internal Combustion Engines (ICE), a key powertrain for the sector. This study evaluates NOx and CO2 reduction potential using an NRMM engine model simulation across test cycles (NRTC, NRSC, LLC) and in-use scenarios. Additionally, test results of an NRMM engine are presented, examining various future exhaust emission control systems combined with advanced engine temperature management strategies. These findings demonstrate the potential for optimizing pollutant reduction technologies and thermal management to meet stringent future emissions standards while maintaining performance and efficiency.

Optical Analysis of Mixture Formation by Spraying Urea-Emulsion Fuel

Ryosuke Takeda･Daisuke Oda･Akihiro Kido (Tohoku Gakuin Univercity)

Conventional emulsion fuel used water, in contrast in this study used urea water mixture. The results of this study provide insight into the mixture formation characteristics of urea- emulsion by comparing it with gasoline and diesel fuels, which are currently the mainstream fuels, and ammonia and emulsion fuels, which are attracting attention as alternative fuel to petroleum, and their respective fuel spraying.

Evaluation of Urea-added Emulsion Fuels by Chassis Dynamometer Tests using an IDI Diesel Engine Vehicle

Daisuke Oda･Ryosuke Takeda･Akihiro Kido (Tohoku Gakuin University)

The Ammonia, which can be generated from renewable energy, has been attracting attention towards achieving carbon neutrality in internal combustion engine vehicles. And a Urea synthesized by ammonia is easy to handle. In this study, various performances of urea-added emulsion fuels when applied to a diesel engine with sub-chamber were evaluated using a chassis dynamometer test.

Development of a CAE Method to Predict Damage to Underfloor Components in Flooded Roads

Hidenori Mayusumi･Jun Miyazaki･Kei Akasaka･Kosuke Nakasato (Nissan Motor)

In recent years, with the electrification of vehicles, plastic covers have been increasingly used in the underfloor area. While driving on flooded roads, the underfloor components of vehicles are subjected to water pressure. These parts must be designed to withstand this pressure without damage. To shorten the vehicle development period and reduce costs, CAE analysis is effective in the design phase. Therefore, we developed a CAE method that evaluates the risk of part damage by coupling fluid analysis using a particle method with structural analysis.

Investigation of the Flow Separation from the DrivAer Notchback Rear Window with DDES and LES

Luca Bauer (Technical University of Munich)･Jonas Sebald (Audi)･Philipp Schlichter･Thomas Indinger (Technical University of Munich)

Computational Fluid Dynamics (CFD) workflows that employ Delayed Detached Eddy Simulation (DDES) typically provide accurate predictions regarding automotive external aerodynamics. However, DDES can exhibit inaccuracies in specific regions of the flow field. This study examines one such critical area: the boundary layer separation from the rear window. Therefore, we benchmark both DDES and Large-Eddy Simulation (LES) against wind tunnel data for the DrivAer Notchback by using an OpenFOAM workflow.

Numerical Investigation of Water Flow in Narrow Gaps of Vehicle Interior Components

Evelyn Sabella Rugerri (Technical University of Munich)･Dirk Baeder (Audi)･Thomas Indinger (Technical University of Munich)

If one unintentionally spills beverages or keeps the sunroof open during a rainy day, several electronic and mechatronic components may be exposed to water. Hence, monitoring water in vehicle interior is part of a growing body of research on water management. This study bridges the physical insights to its virtual representation using a novel Lagrangian 3D-CFD solver. Despite its flexible nature, the computational time for simulation on complex geometries still seeks great optimization. This is to be conducted by means of a mathematical modeling of flows in narrow gaps, whereas the models are obtained empirically using Design of Experiment (DoE).

CFD simulation of BPE on a drum brake

Shuhei Tanamachi･Taisuke Ito･Katsuhiro Uchiyama･Yoshiyuki Yamaguchi (Nisshinbo Brake)

Wear dust particle emissions from automotive brake friction materials are subject to EURO 7 regulations and are an important factor to be considered in the design of friction materials. This study focuses on the particle emissions of drum brakes and presents the results of a CFD simulation parameter study. The actual test results showed similar trends to the simulations.

Numerical Implementation of a Leak Testing Method to be applied to High Voltage Batteries

Matthew Sleight･Stefan Adami (TUM)･Mathieu Mulmann (Audi)･Thomas Indinger (TUM)

The production of High Voltage batteries is a major challenge for the automotive industry. To improve battery production quality, optimizing the leak test would be an important development. This test consists of changing the pressure in the battery and measuring the volume leakage. To do this, CFD simulations are carried out using the SPH method. A numerical model is used to reproduce the different phases of this test. These results are compared with experimental data. The recreated process will help to optimize the process thanks to a better understanding of the phenomenon.

CFD Methods for the Predection of Washer Fluid Behavior during Wiper Operation

Shun Nakamura･Yuta Ito･Arisa Mizutani･Shiro Yasuoka (Toyota Motor)･Gabriel Pichon (Dassault Systems)

A CFD analysis using the LBM coupled with a Lagrangian particle tracking was developed to predict the washer fluid behavior during wiper operation while driving.
This presentation compares the simulation results with the experimental data and shows the development approach with this method.

Research on Aerodynamic Performance Enhancement of an Automobile Through Utilization of Cooling Ventilation

Feiyi Chen･Takuji Nakashima･Takenori Hiraoka (Hiroshima University)･Keigo Shimizu･Yusuke Nakamura (Mazda)･Hidemi Mutsuda (Hiroshima University)

In this study, the feasibility of aerodynamic performance enhancement of an automobile through utilization of cooling ventilation was investigated. A general vehicle model for aerodynamic research was used as the investigated vehicle, and the shape of the exhaust duct leading to the base surface was parametrically optimized to reduce the aerodynamic drag. As a result, the optimal duct reduced overall drag more than the ideal model without radiator ventilation, although the radiator ventilation volume was reduced by half compared to the original model.

Relationship between the window in the tunnel entrance hood and the flow around the vehicle

Naoto Kato･Moeri Okawa (Graduate School of Utsunomiya University)･Keisuke Yoshida (TOYOTA GAZOO Racing Development Co., Ltd.)･Hiroaki Hasegawa (Graduate School of Utsunomiya University)

Tunnel entrance hoods are installed to reduce micro-pressure waves to the tunnels for high-speed vehicles. In this study, computational fluid dynamics is performed to analyze the structure of the flow around a tunnel entrance hood and a vehicle model. The vehicle model is moved by overset mesh. The flow between the tunnel and the vehicle is visualized and the pressure in the tunnel is measured. CFD results are compared with previously reported experiments to confirm their validity.

Identification of flow fields contributing to aerodynamic drag on an automobile using graph-structured analysis

Yusuke Nakamura･Mitsugu Mera･Keigo Shimizu･Kohei Seo (Mazda)･Takenori Hiraoka･Takuji Nakashima (Hiroshima University)

The identification of flow fields contributing to aerodynamic drag using graph-structured analysis is presented. Unsteady computational fluid dynamics simulation was performed to obtain time-series data of the drag coefficient and the total pressure coefficients at probes placed in space. By analyzing these data with graph-structured analysis, a directed graph representing the causal relationship between the positions of the probes and the drag coefficient was visualized. Based on the result, an attempt was made to identify the flow fields contributing to the drag coefficient.

A study on the reduction mechanism of modulated wind noise by numerical simulation reproducing fluctuation of natural wind

Takumi Hirata (Nissan Motor)･Atsushi Tajima (Kobe University)･Takahiro Kamiwaki (Nissan Motor)･Junichi Wakamatsu (Junichi)･Jun Ikeda･Kousuke Nakasato (Nissan Motor)･Chung-gang Li (RIKEN)･Makoto Tsubokura (Kobe University/Riken)

When a vehicle is driving in real driving environments, frequency modulated wind noise may make passengers uncomfortable. We are trying to clarify the mechanism of the frequency modulated wind noise by large-scale numerical simulation which reproduced the fluctuation of the natural winds using ”FUGAKU". In this paper, the reduction mechanism was studied using the numerical simulation for the item with the reduction effect.

Investigation of required spatial resolution of CFD for predicting separation points around A-Pillar

Kazuaki Hiwatashi･Ryuta Yonemitsu･Masayuki Watarai (Honda Motor)･Kazuya Abiko (Auto Technic Japan)･Jiayi Zhang (PERSOL CROSS TECHNOLOGY)･Tsuyoshi Terakawa (Honda Techno Fort)

In the development of wind noise performance, accurate flow evaluation for the aerodynamic design is necessary.
Currently, this verification is conducted with wind tunnel testing, high-precision CFD predictions are necessary to shorten the development period.
In this presentation, required calculation settings to predict A-pillar separation points are investigated. Additionally, the validity of the settings is confirmed by comparing them with wind tunnel test results.

Design with AI assistance

Pablo Montoya Diego (Applus IDIADA)

In an increasingly competitive global environment, there is currently a significant push among automakers to reduce development times for new models. This project is an exploration of Artificial Intelligence tools that have been introduced in the last two years for image and 3D volume generation, and how they can be used by designers to streamline the styling process and save significant amounts of time in turning their ideas into reality, while retaining full creative control over their output.

Challenges and Innovations in Sustainable Urban Vehicle Design.

EMILIA Romero Tienda･Ines Munoz (A43581610)

The design of innovative vehicles for urban environments presents multiple challenges in the context of sustainable mobility. This study examines the current challenges in developing urban vehicles that must comply with the principles of circular economy, carbon footprint and cost reduction, while adapting to the diverse needs of users and travel purposes. Through the analysis of two vehicles, designed for people and goods, outstanding challenges in designing truly versatile products are identified and assessed. This research contributes to the understanding of the key factors for achieving more efficient, safe and tailored urban mobility, aligned with the demands of modern society.

Fusion of Design and Function in Robot Arms and Differential Swerve Drive

Kaito Ota (Tokyo University of Agriculture and Technology)

In designing the robot arm and differential swerve drive, we aimed for a fusion of technical performance and cool design. We will introduce the specific process of pursuing the fusion of function and design, and the points we focused on, while exhibiting actual products.

Reflection of design by featuring infusion molding

Mikio Yonaha･Atsushi Dobata (Fabricators)

Practical infusion molding with simple equipment and one-op enables high-quality small-lot production with high design refrection.
Flexibility in management of derivery term and cost, as well as an improved working environment (reduced solvent exposure).

The Impact of Generative AI on Design Processes and Intellectual Property Management

Yasuhide Yokoi･Masafumi Asakura (Final Aim)

The evolution of generative AI is accelerating design processes and expanding creative approaches. At the same time, intellectual property (IP) risk management and protection have become critical challenges. This report examines the benefits and challenges of generative AI through real-world design case studies. Additionally, it explores the current state of IP management and practical initiatives, proposing next-generation design processes that integrate these advancements.

Assessing automotive cybersecurity vulnerabilities with generative adversarial networks

Miguel Martinez (IDIADA Automotive Technology SA)

In an era where the cybersecurity is a key point for the protection of our daily life. Artificial intelligence has emerged as a solution to improve threat detection, risk assessment and response mechanisms. This paper is focused on the evaluation of vulnerabilities in automotive systems by using deep learning networks to generate attacks and discover vulnerabilities that could not be detected by traditional methods, it is proposed the development of a generative adversarial network (GAN) to reproduce synthetic cybersecurity attacks in the vehicular environment.

Securitization of an automotive FOTA process in compliance with UNECE R155 & R156

Sergi Arjona (Applus+ IDIADA)

The automotive industry is transitioning to Software-Defined Vehicles (SDVs), where software drives functionalities like ADAS and infotainment. This evolution demands secure and scalable firmware-over-the-air (FOTA) systems compliant with UNECE R155 and R156. This project presents a tailored FOTA solution integrating secure boot, RSA signature verification, TLS-encrypted communication, and anti-rollback mechanisms to mitigate threats such as spoofing and tampering. Scalable and efficient, the system ensures update integrity, authenticity, and confidentiality while supporting large fleets. Real-time monitoring and modularity enhance regulatory compliance, positioning secure FOTA systems as vital to SDV development in connected vehicles.

WPA3 technology in Automotive: Enhancing security for connected vehicles.

Ismael Vera (Applus+ IDIADA)

WPA3 has landed to our internet connections, promising new capabilities and improvements from its previous version WPA2. Recently, this protocol has begun to be implemented in connected vehicles. In Applus+ IDIADA, we must stay updated about new emerging technologies in the automotive industry in order to continue being leaders in security testing. The purpose of this paper is to provide knowledge about what can we expect from WPA3, which improvements it brings in terms of security and how is our company preparing to test all its vulnerabilities, aiming to protect the final users and give them the safest vehicle possible.

End-to-End Secure Automotive IoT Applications

Dennis Kengo Oka (TBD)

The automotive world is merging with the IoT world with emergence of Automotive IoT applications where traditional embedded software architectures and development methodologies blend with modern cloud architectures and development. Automotive IoT encompasses vehicles, cloud and mobile devices thus increasing the overall attack surface and potential impact on safety, operation, privacy and finance. As such, it is imperative to consider relevant security solutions for embedded as well as for cloud and mobile. This article presents Automotive IoT use cases, discusses vehicle and cloud architectures, and reviews development processes and security frameworks to enable end-to-end secure development of Automotive IoT applications.

Firmware Security Module

Philipp Jungklass･Claude-Pascal Stoeber-Schmidt･Marco Siebert (IAV)･Jonas Rummel･Taigan Lee (IAV Japan Co., Ltd.)

Modern vehicles based on the conceptual design of the Software Defined Vehicle (SDV) focus on the implementation of new functionalities in software. To secure such vehicles, it is essential to provide a trustworthy and secure enclave that can be used to execute security-relevant functionalities. These secure runtime environments, known as Trusted Execution Environment (TEE), provide the necessary protection mechanisms to achieve the objectives of information security. However, existing TEEs in automotive control units are dependent on dedicated hardware support, which significantly limits their flexibility. For this reason, an alternative, software-based concept for a TEE is presented in this article, which reduces hardware dependencies to a minimum, significantly increasing flexibility compared to previous solutions. To demonstrate the approach, presented here, the secure runtime environment is implemented as an example on an automotive Electronic Control Unit (ECU) platform.

Secure agile software development in the automotive industry

Philipp Jungklass･Carsten Elvers (IAV)･Jonas Rummel (IAV Japan Co., Ltd.)･Claude-Pascal Stoeber-Schmidt (IAV)･Taigan Lee (IAV Japan Co., Ltd.)

Agile methods have established themselves in the development of software for good reasons: they help to incorporate rapidly changing requirements into projects in the best possible way. Regular reviews of iterations through tests also ensure higher quality and more transparency. However, this type of software development contradicts some of the classic requirements of the automotive industry. After all, the development of software for vehicles is subject to process models such as the standardized Automotive SPICE or the V-model, which separates the development process into clearly defined sub-steps. In addition, many other requirements must be observed in the automotive environment, such as the security regulations of the UNECE for cyber security management systems or the specifications for functional safety defined in the ISO26262. For this reason, this article uses an automotive series project to explain the general procedure for meeting these strict requirements using agile methods.

Penetration testing of automotive systems

Claude-Pascal Stoeber-Schmidt (IAV)･Taigan Lee (IAV Japan Co., Ltd.)･Marco Siebert･Philipp Jungklass (IAV)･Jonas Rummel (IAV Japan Co., Ltd.)

To ensure cybersecurity, experts need mechanisms to identify and eliminate vulnerabilities before attackers can exploit them. Penetration tests are crucial in this process, enabling specialists to recognize and close potential security gaps early. By developing specific attacker models and using advanced techniques like scanning, attack simulations, and vulnerability analysis, penetration testers can uncover hidden security risks. This systematic approach not only identifies vulnerabilities but also helps understand how they could be exploited, such as stealing protected data or compromising systems. For this reason, this article uses a series project from the automotive sector to describe the general procedure and the correct use of the various test methodologies.

Development of Gas-blow Hot Stamping Method for Achieving Integrated Components.

Masahiro Kubo･Satoshi Shirakami (Nippon Steel Corporation)･Noboru Itagaki (Sumitomo Heavy Industries, Ltd.)･Manabu Nishijima (Imanishi Manufacturing Co.,Ltd.)･Hiroshi Yoshida (Nippon Steel Corporation)

The author's group has been developed element technologies for parts integration by hot stamping. In this study, we developed a gas-blow hot stamping method that produces closed sections in a single step from sheet steel materials, and also conducted prototype tests to verify the formability and the compont properties.

Development of Large-scale Integral Forming Technology by Hot Stamping

Kenta Ikegami･Masahiro Kubo･Satoshi Shirakami･Hiroshi Yoshida (Nippon Steel)

We developed new large-scale integral forming technology by hot stamping. The new forming method enables both bend forming from vertical direction and draw forming from lateral direction in one stroke hot stamping. We integrally formed prototype surrounding rear floor panel including wheel-house-inner by using new forming method actually. Further, we demonstrate that the integrally formed structure with hot stamping materials contribute to the improvement of collision performance.

Development of Resistance Spot Welding Technology Using Pulsed Current Waveform Control and Automatic Off-Time Control for Three Sheets Stacks with High Sheet Thickness Ratio (Part 1)
-CDC New Spot Welding Technology-

Shinya Watanabe･Hitoshi Saito･Xihao Tan (Honda motor)･Hiroki Toyoda･Rinsei Ikeda (Osaka Univ.)

As more and more cars are being converted to BEVs, vehicle body requirements for protecting passengers and batteries are becoming stricter, and ultra-high tensile steel is increasingly being used for stiffeners and inner members. On the other hand, outer panels are becoming thinner, and the number of thin-thick-thick three sheets stacks with high sheet thickness ratio (hereinafter referred to as difficult sheet stack) in which it is difficult to ensure the weld diameter of the thin plates while suppressing expulsion is increasing. In this paper, we report on a new spot welding method (CDC welding method) developed to solve this problem, its welding mechanism, its effect of expanding the range of weldable sheet combinations and its effect of suppressing expulsion, in comparison with conventional direct current inverter (hereinafter referred to as DC) welding.

Development of Resistance Spot Welding Technology Using Pulsed Current Waveform Control and Automatic Off-Time Control for Three Sheets Stacks with High Sheet Thickness Ratio (Part 2)
-CDC New Spot Welding Technology-

Shinya Watanabe･Hitoshi Saito･Xihao Tan (Honda motor)･Hiroki Toyoda･Rinsei Ikeda (Osaka Univ.)

As more and more cars are being converted to BEVs, vehicle body requirements for protecting passengers and batteries are becoming stricter, and ultra-high tensile steel is increasingly being used for stiffeners and inner members. On the other hand, outer panels are becoming thinner, and the number of thin-thick-thick three sheets stacks with high sheet thickness ratio (hereinafter referred to as difficult sheet stack) in which it is difficult to ensure the weld diameter of the thin plates while suppressing expulsion is increasing. In this paper, we report on a new spot welding method (CDC welding method) developed to solve this problem, its welding mechanism, its effect of expanding the range of weldable sheet combinations and its effect of suppressing expulsion, in comparison with conventional direct current inverter (hereinafter referred to as DC) welding.

Development of Suede Surface Application Technology for Interior Instrument Panels

Kento Imai･Yushi Shinno (Honda Motor)

In recent years, a variety of decorative expressions have been applied to automotive interiors, utilizing not only synthetic leather and fabric but also suede materials that can convey a higher quality feel. Suede is a material that does not stretch as easily as synthetic leather, which limits the shapes that can be formed. Therefore, when applying it to large and complex shapes like instrument panels, it has typically required part segmentation or the lamination of suede materials, resulting in a more complicated manufacturing process. Additionally, hand application has been common, leading to higher labor and cost requirements.
In this project, we developed a technology that uses conventional automatic application equipment to apply suede materials with a manufacturing cycle equivalent to that of existing synthetic leather surfaces. This allows us to apply suede to complex instrument panel shapes without segmentation, achieving suede-covered instrument panels without changing the existing manufacturing process.

Highly electrical insulating and heat-resistant molding compound using diallyl isophthalate resin

Chiharu Inoue･Ryoichi Igawa (Sumitomo Bakelite)

As electric vehicle systems become higher voltage, their components are required to have higher insulation and heat resistance than ever before. Using diallyl isophthalate resin, we have developed a material that has both high insulation properties with tracking resistance of 800V or more and heat resistance that reaches a glass transition temperature of 235℃. Thin-wall molding using an injection molding machine is also possible, which can lead to smaller parts and higher heat dissipation.

Development of a water-based hard coat material for Plastic Glazing

Mifuyu Niwa･Kentaro Shiraishi･Hiroaki Takanohashi (Asahi Kasei)･Kazufumi Iwai･Daisuke Orihashi (RENIAS CO., LTD)

There is a growing demand for plastic glazing to reduce vehicle weight and improve fuel efficiency.  Utilizing our proprietary nano-structure control technology, we have developed a water-based hard coat material with high abrasion resistance equivalent to ECE R43 Class L requirements. In this presentation, we will report on the characteristics and properties of the water-based hard coat material.

Development of a Process Analysis System Using Image Processing (First Report)
-Practical Validation of an Automated Analysis System for Logistics Processes-

Takuma Sugino･Hirofumi Morishita (Toyota Motor)･Gianpiero Francesca･Sven Meier (Toyota Motor Europe)･Kazuhiro Shintani (Toyota Motor)

We are developing a system that enables field workers in the automotive manufacturing process to independently conduct process analysis using AI detection models. In this study, we constructed a system that automatically analyzes the efficiency of logistics transportation processes based on information obtained from cameras. Through comparative evaluation of the proposed system and conventional analysis method under actual operational conditions, we confirmed that the proposed system can achieve analysis with accuracy comparable to conventional method, while reducing the required effort by approximately 90%.

Development of High-Rresponse Heat Insulation Material Technology in Engine Combution Chamber to Improve the Fuel Economy （4th Report)
-Development of Adhesion Model and Substrate Surface Roughening Model for Heat Insulation Material-

Kai Yamamura (Mazda)

To decrease cooling loss of engines and improve fuel economy, we are developing heat insulation material technology. In order to achieve sufficient adhesion of the heat-insulation coating, the substrate surface should get roughened for mechanical bonding. We developed a new method to quantify adhesion and revealed which roughness parameter to control. In addition, we developed the surface roughening model to achieve desirable roughness efficiently.

Simplified Evaluation of Internal Residual Stresses in Steel: Proposal of the Half-Cut Method

Satoru Nishida･Eiki Kobayashi (Akiyama Seiko)･Souichiro Nishino (Ibaraki University)

The measurement of internal residual stress in drawn round steel bars is challenging. We propose a half-cut method to evaluate the internal residual stress calculated through FEM analysis of the drawing process, using X-ray diffraction. A half-model is employed for FEM analysis, where the symmetry plane constraints are released after drawing. The evaluation is conducted by measuring the axially half-cut plane using X-ray diffraction.

Quality Improvement of Mastic Application Areas through the Utilization of Body Thermal Deformation CAE

Koichiro Oi･Takeshi Kashiyama･Toshiro Ohori･Moe Yasue (Suzuki Motor)

In automobile manufacturing, the roof panel and its internal structural components are bonded using a heat-curing elastic adhesive known as mastic.
After the mastic is applied during the body assembly process, it is cured utilizing the heat from the paint shop's oven .
However, instances of unintended deformation of the mastic have been observed during this curing process.
Assuming that the cause is the thermal deformation of the body during the oven curing, we investigated it through various experimental and CAE analysis. This report presents the results of these investigations.

Analysis of lifespan distribution, dirt and deterioration state of seat belt webbing recovered from End-of-Life Vehicles for Closed-loop Recycling (First report)

TAKERU FUKUDA･MASATOSHI KOBAYASHI (Honda R&D)･RUMI OGAWA･YUTAKA FUJIWARA (Sumika Chemical Analysis Service)

When recycling ELV PCR into recycled materials, the quality of the PCR is thought to have a significant impact on the condition of the PCR. In order to stabilize the quality of the recycled materials, it is important to understand the quality of the PCR. In this study, seat belt webbings from approximately 700 ELVs were collected for only five days in early March 2024. The results of the analysis of the distribution of age, dirt, and deterioration are reported here.

Verification of driver's delay time (τL) due to differences in automotive Seat speficications.

Tetsuhiro Okuda･Tomoya Kato (TOYOTA BOSHOKU)

Driving operability is a crucial performance factor in the domains of handling stability and ride comfort, particularly in the context of automotive seat characteristics. However, its evaluation has traditionally relied on sensory assessments, making it challenging to incorporate into design processes. To create automotive seats that are easy to drive with and ensure safety and comfort for the driver, this study aims to quantify driving operability based on differences in seat characteristics.

Influence of driver seating position on steering characteristic evaluation

Motoharu Hattori･Masato Abe･Yoshio Kano･Masaki Yamamoto･Makoto Yamakado･Naoya Nishimura (Kanagawa Institute of Technology)

As vehicles become increasingly electrified, their specifications are shifting closer to those of low-center-of-gravity sports cars. This transformation is characterized by a lower center of gravity height, reduced pitch and yaw moments of inertia, and a rearward shifted center of gravity. However, due to the placement of the battery under the floor, the driver's seating height remains relatively high, distinguishing these vehicles from traditional low-center-of-gravity sports cars. This study investigates how differences in the driver's seating position influence steering characteristics by presenting experimental results obtained through a driving simulator evaluation.

Perfect tracking driver model aiming for perfect curve tracking based on vehicle dynamics and control design theory
-Don't combine Kondo model with feedforward!-

Hideki Sakai (Kindai University)

I propose a driver model that combines FF and FB to improve the curve-following performance of lane-keeping control. The FF section uses a dynamic inverse model of the vehicle model. Combining any FF section with the Kondo model, which was derived on the premise of a straight line, actually worsens the curve-following performance. Therefore, for the FB control section, a customized PID control is used by extending the operating principle of the Kondo model to a curve. As a result, when there is no disturbance, it is possible to follow a target course that does not include a break point with zero error. When a constant disturbance force is applied, the vehicle can turn with zero error in the steady-state response of a constant radius turn. The effectiveness of this control system has been verified by numerical calculation.

Vehicle Motion Analysis Using Deep Learning Coordinate Transformation

Masanori Harada･Yuki Ueyama (National Defense Academy of Japan)

This study investigates the deep learning coordinate transformation for vehicle motion analysis. For a course layout with a mixture of straight and curved shapes, constructed deep learning coordinate transformation can generate the lateral position and the curvature. Numerical examples show that the proposed idea can be easily applied to lane following or optimal trajectory generation.

The Influence of Vertical Suspension Friction on Planar Vehicle Dynamics (second Report)

Ayumu Tanaka･Yasuji Shibahata･masaaki Minakawa･Makoto Yamakado･Masaki Yamamoto･Masato Abe･Yoshio Kano (Kanagawa Institute of Technology)

In the first report, the effect of suspension vertical friction on vehicle planar motion through roll steer was analysed. In this paper, the same study was conducted on the initial toe, and it was clarified that it mainly affects the plane motion in the on-centre region. Furthermore, the effects caused by the coupled relationship between roll and plane motions were examined and compared in terms of the degree of these effects.

Vehicle Dynamics Simulation taking into considerations of pneumatic brake system for Autonomous driving of Heavy-Duty Vehicle

Hiroo Yamazaki･Katsuya Yashiro･Yoshiki Watanabe (UD Trucks)

It is difficult to perform tests using actual vehicles in low adhesion conditions between tire and road surface or critical situations and/or worst cases. To confirm above requirements with keeping safety, the modeling for nonlinear tire model, nonlinear pneumatic model for braking system and modeling for parking brake system are done and the vehicle dynamics simulation are developed considering above characteristics. In this study, modeling for parking brake for heavy duty vehicles were performed. Modeling for contact force for parking brake system taking into consideration for spring braking force was done and those simulations were performed.

Development of Traction Control Method using Fluctuation Information of Rotational Velocity of In-Wheel Motors

Masaru Yamasaki･Toshiyuki Ajima･Wataru Hatsuse (Hitachi)

To improve vehicle stability on slippery road surfaces, we developed a new traction control system that estimates the slip rate based on the relationship between the torque and the fluctuation of the rotation speed of the in-wheel motor. In this presentation, report the principle of the control method, its implementation method, and the results of verification of its effectiveness on a test vehicle.

Development of Damping Control for Vertical Vibration Using Driving Force of In-Wheel Motors to Improve Passenger Comfortability

Naoki Hatta･Masaru Yamasaki･Toshiyuki Ajima (Hitachi)･Sakahisa Nagai･Hiroshi Fujimoto (The University of Tokyo)

In-wheel motors (IWMs) can utilize larger drive reaction forces for controlling sprung mass motion compared to conventional drive systems that use a drive shaft, since the driving force of IWMs directly acts on the tire contact surface. In this study, we design a controller aimed at enhancing damping effects in the 4 - 8 Hz frequency range, known to cause discomfort for passengers, by analyzing sensitivity and Nyquist plot. The effectiveness of the controller was validated through vehicle testing.

Driving stabilization technology using Model Predictive Control including Reference Vehicle Model

Hiroki Obara･Shinji Ishihara (Hitachi)･Atsushi Yokoyama･Hiroki Sonoda･Yuichiro Minakuchi･Yusuke Honjo (Hitachi Astemo)

We have developed the driving support function that cooperates multiple actuators to improve driving stability. This paper shows the driving stabilization technology that modifies the reference vehicle state in the prediction to the value that does not exceed the vehicle limit by having a reference vehicle model in the model predictive control, in order to realize the vehicle behavior based on driver operation while maintaining stable driving.

Influence of Trail Braking Maneuver on Vehicle Cornering Behavior

Ikkei Kobayashi･Fumiya Yoshida･Liting Fu･Wenbao Wu･Jumpei Kuroda (Tokai University)･Kazuki Ogawa (Aichi University of Technology)･Peeie Heerwan Bin Mohamad (University Malaysia Pahang)･Hideaki Kato･Takayoshi Narita (Tokai University)

Trail braking is a maneuver in which a vehicle is given brake torque and steering simultaneously. This maneuver is used in race cars when deceleration is required at corners, and it significantly affects the vehicle's cornering behavior. In this study, we will report on the analysis method and results of the effect of trail braking on roll and pitch dynamic and stability and control.

A Basic Study on Meandering Motion of Multi-Articulated Vehicle

Sunao Chikamori (Former Job : Seikei Uniersity)

Since we judged that the meandering motion that occurs in multiple articulated vehicles is one of the problems that must be solved, we decided to elucidate the mechanism of this movement and consider the direction of the solution.
Using the relationship between the forward vehicles motions (yaw rate and lateral velocity) and rearward vehicles same motion, which is established when the steering angle is small and driving locus to a straight line, all the created equations of motion were converted into descriptions using state variables

Verification of PBV driving performance for universal mobility using suspension module test rig

Seungmin Kwon･Hyunjae Lee･David Song･Seonghun Kim･Jongho Ko･Yongsub Yi (Hyundai Motor)

In this study, we conducted a system-level performance verification and real-vehicle level performance prediction of a low-floor suspension (transverse leaf spring CTBA) to be applied to TSD-R1. We analyzed the behavior and stiffness of the suspension during the handling maneuver through K&C characteristic evaluation using SPMD testing. We also analyzed the ride comfort characteristics by analyzing the load transmitted to the chassis mounting points through system-level ride comfort evaluation, and predicted the real-vehicle unit performance based on this.

Development of MF(Magic Formula) Tire Model Application Technique

Jinhee Lee (Hyundai Motor)

One of the important factors in vehicle dynamics simulation is to express the interaction between the tire and the road surface accurately because the behavior of the vehicle depends on the force and moment applied to the tire. MF(Magic Formula) tires are mainly used in most vehicle dynamics SW to express tire characteristics that show nonlinear and complex behavior against the load applied to tires with various contact conditions. This paper proposes a method for effectively utilizing tire models in the vehicle performance development stage. The first of them is to immediately extract the major tire characteristics from the tire model, and the second is to find a model parameter combination that satisfies the target tire characteristics by applying an optimization technique.

A Study on Harmonic Performance for EV SUV Aftershock Improvement
-In View of Frequency Seperation and Bushing Cahracteristics-

TAEHEE LEE･DAE-UN SUNG･YONG-HYUN RYU (Hyundai Motor)･SU-HYUN LIM (PH Company)･JIN-HWAN OH (DH R&T Company)

In the event of an impact such as a bump, the tendency to worsen aftershocks(or post-impact oscillaton) and low-frequency driving vibrations increased. What are the characteristics of a vehicle with excellent rear-wheel aftershocks? Compared to the characteristics of a vehicle with unfavorable rear-wheel aftershocks, most important differences could be identified

Vehicle Motion Control on Electric Vehicles
-Capabilities on connecting Chassis and Powertrain Features-

Tobias Vosshall･Martin Dorn･Thomas Reckeweg･Frank Schummers･Michael Struth (FEV)

This paper presents a novel approach to vehicle motion control on electric vehicles, which aims to coordinate and manage multiple vehicle systems and controllers across all vehicle domains. It defines the prerequisites to enable vehicle motion control, such as vehicle architecture, communication, sensors and actors. Focusing on connecting chassis and powertrain features selected software functions are developed in a Matlab/Simulink environment and verified in a co-simulation environment of Matlab/Simulink and CarSim. The paper concludes that the proposed motion controller can enhance the vehicle performance, efficiency, and safety.

Mechanism Design of Suspension and Steering Systems for Balancing Mobility and Maneuverability

Mengjian Tian (Shenzhen Technology University)

To make human society more convenient, high-speed vehicles are increasingly expected to possess low-speed mobility, such as the ability to rotate in place or move laterally, enabling more flexible movement. Consequently, the question of what kind of suspension and steering systems are required has been raised.
For instance, ensuring high-speed stability and steerability necessitates setting a small scrub radius for the suspension. However, achieving flexibility during low-speed operation requires a large steering angle for the tires. To prevent motion interference, it may be necessary to increase the scrub radius or compromise the rigidity of the suspension and steering systems to some extent.
To address these challenges, it is crucial to conduct research into the design of new suspension and steering system mechanisms, taking into account factors such as suspension geometry, coexistence with in-wheel motors, and various other elements.

Machine Learning-Based Method of Determining Target Characteristics for Road Noise Reduction (Second Report)
-Development of Methods for Exploring Multiple Specifications-

Kei Ichikawa (Honda Motor)･Koji Tachioka (Estech)･Jun Tsutsumi･Yuta Shimamura (Honda Motor)･Hiromichi Ebisawa (Estech)

Determining target characteristics for vehicle parts against road noise requires extensive trial and error with actual vehicles and FEM. This study explores methods to determine multiple target characteristics for different part combinations through repeated optimization and clustering using machine learning model.

Asymmetry of tire vibration as a source of road noise

Masao Ishihama (Ishihamagiken Consulting)

Regarding road noise, the process by which tire vibrations during rolling are converted into excitation forces on the axle was not fully understood. In this study, a simple mechanical model was used to explain the process by which the asymmetry in the circumferential and widthwise distribution of vibration waves propagating along the tread due to excitation from the road surface is converted into excitation forces on the axle.

A Method for Measuring Instantaneous Structural Intensity in Flat Structures

Keisuke Abe (SUBARU / Kanagawa University)･Hironori Yamada (SUBARU)･Toru Yamazaki (Kanagawa University)

A measurement method of instantaneous structural intensity was developed to visualize the active component of vibrational energy in the early stages of propagation. A formulation is proposed to derive an approximate solution for the instantaneous structural intensity using the Finite Difference Method (FDM) for a flat structure. The validity and practicality of the method were demonstrated by comparing experimental results with FEM analysis result.

Extraction of high contributing acoustical modes in luggage room space model using principal component contribution analysis

Junji Yoshida･Reo Matsui (Osaka Institute of Technology)･Norihisa Nakajima･Shoya Noguchi･Ichiro Fukumoto (Kasai Kogyo)

Road noise characteristic in cabin is affected by not only the input force from tires but also the body vibration and acoustic cabin space characteristics. In this study, we focused on the noise from rear tire via luggage room space and attempted to find out high contributing acoustical mode by combining operational transfer path analysis method and CAE.

Experimental Study on the Measurement Conditions of Road Noise by Chassis Dynamometer

Tomoki Ichikawa･Toshiyuki Nakamura･Hiromasa Hayashi･Naoya Murakami (HAYASHI TELEMPU CORPRATION)

The method of measuring road noise using a chassis dynamometer installed in a semi-anechoic room is not generally standardized in Japan. Therefore, the current situation is that each company conducts experiments in different conditions. In this report, road noise (sound pressure level at passenger ear position) was measured in various conditions, such as warm-up time and lashing condition etc. As a result, the contribution of various conditions to the measurement results was examined.

A Study on Structural Optimization by Varying Plate Thickness to Minimize Vibration Response Energy due to Displacement Excitation using FEM（2nd report: Influence of Evaluation Point on Sound Pressure）

KATSUHIKO KURODA (Nagasaki Institute of Applied Science)

Currently, there is a trend in the body parts of electric vehicles to reduce the number of parts by one-piece molding. In this paper, the target structure is a beam that connects the left and right joints of the suspension section and the thin plate at its bottom, and the objective function of the structural optimization method is vibration response energy, using a method of moment excitation of base excitation by FEM. The purpose of this study is to investigate the effect of the evaluation points on the sound pressure of the results obtained by the structural optimization method.

Building of Multibody Dynamics and Machine Learning Hybrid Model and Application to Drivetrain Tortional Vibration Development

Ryu Chikasue･Roberto Gonzalez Flores･Seijun Morita･Kazuhiro Tanaka･Kenji Kudo (Mazda)

In order to reduce CAE simulation time using machine learning, one important issue is how to build a machine learning model that can be used without re-collecting data and retraining when the system’s design changes. In this study, we suggested a hybrid approach to use machine learning model (LSTM) representing non-linear components that cause simulation difficulties (e.g. DMF including contact behavior) in a drivetrain multibody dynamics model. A maximum 90% simulation time reduction was confirmed when we applied this approach to the development of drivetrain tortional vibration.

Analysis of the Mechanism of Vibration During THS Engine Start-up Due to HEV Damper Characteristics

Masaki Sagawa･So Shimizu･Yuki Notake (Toyota Motor)

The THS system connects the engine and driveshafts through a planetary gear, causing vibrations to be transmitted not only through the engine mounts but also via the driveshafts to the vehicle body during engine start-up. This study reports that the torsional characteristics of the damper, particularly around 0Nm, significantly impact engine start-up vibration.

Application of PT-VRS in a non-echo environment for vehicle vibration and noise development

Yoshihide Narita (Toyota Motor)

In recent prototype-less vehicle development, PT-VRS has been utilized during platform development, primarily focusing on the dynamic performance in low-frequency ranges .
This report introduces case studies on the application of PT-VRS in a non-echo environment for developing vehicle vibrations and noise from low to mid-frequency ranges.

Study on Amplitude Dependent Friction Damping at Joints and Development of a Simple Estimation Method

Sotaro Tajiri (NewtonWorks)

Dissipation due to friction at the joint interface contributes to the vibration response of a structure, but it is difficult to evaluate quantitatively. In this study, vibration tests and nonlinear dynamic contact analysis were performed on a simple bolted joint structure to evaluate the amplitude dependence of damping caused by friction. In addition, a simple method was developed to estimate the friction damping of a structure from the static contact state and natural vibration mode.

The Method to Break Down NVH Performance Targets from Vehicle Sound Pressure to Component Eigenvalues

Takuro Sonoda･Koji Saito (Altair Engineering)･Mari Nakagami (DAIHATSU MOTOR)

In order to define target for each component in early stage of development, the method to break down NVH performance target from vehicle sound pressure to component eigenvalues are proposed in this paper. At first, the degree of freedom of each component which consist of full vehicle is reduced by modal reduction method, and then, sound pressure target values are broken down by understanding relationship between component eigenvalues and sound pressure with using that modal reduction model. By applying this method to product development, the availability of this method with a realistic man hour within the product studying duration was shown.

Development of Bionic Cooling Fan for Radiator

Laurent Art･Peter Kroner (MAHLE Behr)･Hotaka Tsuchiya (MAHLE Behr Japan)

As BEV batteries become larger, one of the problems users face is the electric fan noise that occurs during fast charging. To address this issue, MAHLE has adopted bionic design in the fan design and developed a new electric fan based on the feathers of an owl. By optimizing the shape and thickness of the blades, we achieved a noise reduction of up to 4 dB.

Proposal of entire NVH simulation process for eMotor under various load spectra and correlation study to measurements

Anton Plank･Oliver Grieshofer (Magna Powertrain Engineering Center Steyr GmbH)･Fumio Numata･Kazumasa Kato (Magna International Japan)

The general acoustic behavior of electric drives and their tonal noise is well known and one of the main challenges in integrating electric drives in passenger cars. Common simulation methods, like finite element and multi body system analyzes, have been successfully applied in the electric drive development. However, to combine eMotor excitation and structural dynamic behavior in the relevant frequency range with adequate accuracy, models are getting quite complex and simulation efforts are increasing significantly. Semi-automated set-up of analysis and post-processing reduces the manual work and enables analyzing a large set of data. An introduction to this process is shown.

Seat Structure with High Damping Mechanism to Reduce Body Motion

Hideki Hitomi･Kota Koyanagi･Naoharu Tamura (Honda Techno Fort)･Yukio Kobayashi･Takafumi Tomida･Osamu Inaba (Honda Motor)･Takayuki Toyoshima (Honda Racing)

A seat structure that improves ride comfort was investigated. The seat frame was made into a pan structure by removing the elastic elements. The seat pad has a structure that generates damping force through air resistance, resulting in high damping. Experiments using a prototype seat revealed that this structure is effective in reducing vibration amplification, increasing the shock absorption effect, and suppressing unpleasant shaking.

Dynamic Substructuring for Predictive Approach of EPS Operation Noise

Hirotaka Kamano (Toyota Motor)

Dynamic Substructuring represents a principal method for performance prediction, whereby the dynamics of the system is analysed by means of its individual components. The present study demonstrates the possibility of calculating the response of the assembly by experimental modelling of substructures, specifically the EPS gearbox, bushings and the subframe. The influence of various measurement methods on the prediction is also investigated.

Effects of Inclusions at Joint Interface on Vibration Characteristics of Bolted Joints

Tristan Samuel Britton (Fujimori)･Keisuke Inoue･Yoshinao Kishimoto･Yukiyoshi Kobayashi･Shogo Isobe･Yuuki Kawaharabashi･Satoru Kuga (Tokyo City University)

Bolted joints are used broadly on automotive structures, and it is known that bolted joint vibrational characteristics (ex: Natural frequency, damping ratio) are available to be simulated from the interface’s tribology. This study has been evaluated by experiments and finite element methods for inserting inclusions such as elastic rubber material and adhesive between the joint’s interfaces, that how effects to vibrational characteristics for bolted joints.

Fatigue Damage Degree Evaluation of C-SMC Using Thermoelastic Temperature Variations

Atsushi Akai (Toyota Central R&D Labs., Inc. (Present Affiliation: Kyoto University of Education))･Yasumoto Sato (Toyota Central R&D Labs.)･Yukihiro Hamada･Atsushi Mikuni (Toyota Motor)

Recently, C-SMC—a discontinuous carbon fiber-reinforced plastic produced via sheet molding compound methods—has attracted significant interest in the automotive industry owing to its reasonable balance between the mechanical properties and production efficiency. A reliable technique for evaluating the fatigue damage of C-SMC is required to guarantee its long-term use. In this study, a technique for assessing the fatigue damage degree of C-SMC using the non-dimensional thermoelastic temperature amplitude is proposed, and its effectiveness is investigated.

Effects of Tension and Bending Loads on the Fatigue Threshold in a Stainless Steel Sheet (Part 2)
-Changes due to Stress Ratio-

Gyoko Oh･Atsushi Umezawa (Tokyo Roki)

In this study, we proposed a method to predict the change in the threshold stress intensity range ∆Kth by quantifying the effect of stress ratio using the strength factor of a Walker-type function for fatigue fracture in mode I under tension load and in mode IIII under plane bending load. The effect of the crack front shape was taken into account, as well as the plastic zone size at the crack tip. We also presented a prediction model for the effective stress intensity range that takes into account the plasticity-induced crack closure effect associated with the plastic strain hardening effect.

Fatigue Life Prediction Method for Point Joints Considering Multiple Fracture Modes
-Fatigue Life Prediction Method for Flow Drilling Screw (FDS) joints-

Hiroaki Kawamura･Eita Niisato･Suguru Goto･Kazushi Urakawa･Sogo Takuno･Toshiyuki Isono (Toyota Motor)

This paper describes a fatigue prediction method for the point-based joints in car bodies. There are two directions of fatigue crack propagation, the sheet thickness direction and the interpolate direction, for the fatigue fracture of point fasteners. It is essential for accurate fatigue life prediction to consider the crack propagation direction using numerical simulations. Previous papers proposed simplified joint models for vehicle bodies’ fatigue life prediction that assumed a specific fracture mode. It took a lot of work to simultaneously estimate multiple fracture modes using a particular model. Therefore, they needed to use various models properly or to consider complicated parameter combinations. This paper proposes a fatigue life prediction method considering multiple fracture modes simultaneously. A simplified model representation method is introduced for Flow Drilling Screw joints.

Numerical simulation for lap joints considering adhesion

Hirofumi Sugiyama･Tomoki Nomura･Shigenobu Okazawa (University of Yamanashi)

This paper proposes a numerical simulation method that considers the adhesion region using a damage model and numerical techniques for multi-material structures. The damage model is based on continuous damage mechanics and can deal with the softening behavior of the adhesion region. Furthermore, numerical techniques express the crack path explicitly. Finally, the representative numerical example shows that the novel method is verified.

CAE Analyses for Rotary Friction Welding of the Dissimilar Metal Pipes with Closed Forging Method
-Adjustment Analyses for Exploring Construction Conditions of RFW Bonding of the Pipes with MBD Method-

Tomohiko Ariyoshi (Atori CAE)

With CAE Analysis Method for Rotary Friction Welding of the Dissimilar Metal Pipes by Closed Forging Method, We Aim to Get the Construction Conditions in the Early Stage of the Parts Development.

A Study on Vaporizing foil actuator welding (VFAW) for steel-aluminum dissimilar metals joining without hardware

Hyuckmin Kwon･Junyeong Jeong･Changyeol Yoo･Younil Jung (Hyundai Motor)･Taeseon Lee (Incheon National University)

This study investigates the use of Vaporizing Foil Actuator Welding (VFAW) for joining dissimilar metals, specifically targeting the union of steel and aluminum alloys. VFAW is an innovative solid-state welding technique that utilizes the rapid vaporization of a thin metallic foil to produce a high-velocity impact, enabling strong bonds between different materials. The main goal is to examine the microstructural and mechanical properties of the joints formed between steel and aluminum, which pose challenges for traditional welding methods due to their differing thermal properties and the propensity to form brittle intermetallic compounds. The results highlight the potential of VFAW to produce high-quality dissimilar metal joints, offering valuable insights for its application in the automotive industries where steel-aluminum hybrids are increasingly desirable for their combined strength and lightweight properties.

Research on securing the formability of aluminum 7000 series 3D printing alloy and optimizing heat treatment through adding Zr inoculant and refining crystal grains to achieve high strength and elongation of body structure

Hyomoon Joo (Hyndai Motor Group)

Solidification cracks caused by columnar grains in precipitation-hardenable Al alloys such as 7000 series limits the applicability of laser-based-3D printing. Recently, cracking has been effectively reduced by introducing equiaxed grains through inoculant addition to Al alloy powder. However, the mechanisms through which equiaxed grains can prevent cracking have not been explained from the viewpoint of both microstructure and process parameters. In this study, a solidification cracking model was proposed using the parametric L-PBF results of ZrH2 particle-added A7075, where equiaxed grains were formed as a function of energy density. Through this, we aimed to achieve high strength of body parts.

Investigation of the Modeling on Crush FEM of Aluminium Components

Shingo Nakajima･Ryohei Yukishige (Kobelco Reseach Institute)

Falling-weight tests were performed on test specimens of aluminum cast components to obtain load behavior and deformation behavior. Additionally, simulations of the fallling-weight tests were conducted using FEM and compared with the test results. In the FEM analysis, the effects on load behavior and deformation behavior were investigated by examining the modeling methods for element types, material properties, and variations in fracture characteristics.

Advanced numerical method for weight optimization under consideration of integrated and innovative design trends

Jan Ophey (FEV Vehicle GmbH)･Michael Hog (FEV Group)･Noriyuki Muramatsu (FEV Japan)･Max Krause･Christian Kuerten (FEV Vehicle GmbH)

Giga casting - the start of the revolutionary trend of integral design in the body-in-white for decades, with the aim of reducing the number of parts, streamlining the production process and minimizing development and production times. Integral design is not limited to Giga casting but also leads to new concepts for a variety of materials and approaches. Hand in hand, comes a need for advanced numerical optimization methods which enable a holistic CAE-based weight reduction. By optimizing shape, material and thicknesses such an approach is established and performed on a representative integral design part.

Process improvement of structural strength development using AI Surrogate Models

Mikimasa Kawaguchi･Motoki Tanaka･Takashi Ebisugi･Toru Nakano･Jun Nishikawa (Mazda)･Bisser Raytchev (Hiroshima University)

In MBD for structural strength development, it is essential to identify optimal solutions for conflicting functions. However, the lengthy timeframes associated with model creation and computation present a challenge in the early stages of development. This study introduces an optimization study technique that employed machine learning. These findings will be employed to determine the configuration during the early stage of the next-generation power source’s development.

Development of crashworthiness evaluation method using simplified test structures and verification of fracture prediction technology

Takahiro Aito･Takeshi Kawachi･Eriko Shimoda (NIPPON STEEL CORPORATION)

We developed a test method that can reproduce the collision deformation mode of the front side member in a simple hat-shaped structure. It is possible to express the difference in the occurrence of material fracture due to the bending property of high strength steel sheet, and the difference in the occurrence of spot weld fracture due to spot welding conditions. In addition, the accuracy of the fracture prediction technology using FEM analysis was verified.

A Study on the Optimization of Door BIW Structure Using Thin Casting Method

SANGJIN LEE･JeongMin Kang･DongHa Kang･JungHan Kim･SangYoung Im･SeongHwan Seo･HeeBeom Yang (Hyundai Motor)

The integrated molding reduced the number of parts based on door INR ASSY from four to one, and the entire welding point and adhesive were removed. In order to cope with the process and secure the stiffness of major parts, the thickness was flexibly designed to be 2 to 3T as needed. The number of door assembly processes is reduced from 13 to 8 due to the change in the construction method.

The Development of the TPV Door Inner Belt WeatherStrip meets Wind Noise Targets and Prevents Glass Sliding Squeak Noise Simultaneously

Jeehoon Seong･Sanghyun Lee･Boram Kang･Jungdae Kim･Jaehoon Kim･Youngchel Sin (Hyundai Motor)

As vehicles become electrified and sophisticated, the wind noise problem while driving is becoming more important. Among them, the sound insulation performance of the door's inner belt weatherstrip is essential, as it blocks noise from penetrating into the cabin through the door. However, it became lessened as a consequence of minimizing the lip overlap between the door glass to decrease the squeaking noise when the glass is being operated(going down). In this study, the lip overlap and contact load will be defined first to satisfy wind noise performance and simultaneously develop a standard shape of section that does not generate squeak noise.

Package and design study for application of B pillar less door

YONG HYUN NAM･HYONG DON KIM･CHUNG SIK YIM･KYU HOON CHO (Hyundai Motor)

We are working hard to secure advanced product competitiveness in preparation for the upcoming era of autonomous driving. In the era of autonomous driving, the space inside the vehicle for passengers to engage in various activities other than driving is an important factor, and B-pillarless doors are becoming an essential element for securing interior space. To implement this, we conducted research on vehicle packaging elements and design implementation, and were able to reach a conclusion close to reality by manufacturing an actual vehicle. Through this research, we will introduce the packaging and design elements necessary for B-pillarless doors.

Development of PBV powergate system
-High durability powergate mechanism-

Duck young Kim･Jung hoon Park･Dong wuk Choi･Doo young Jung (Hyundai Motor)･Seong tae Hong･Kwang hun Hong･Hyun seok Choi (PHA)

Purpose Built Vehicle (PBV) is an eco-friendly vehicle that can be delivered at a low cost to meet business objectives and needs. It's a multi-purpose mobility vehicle with a simple architecture that can be designed to meet a variety of requirements. It can also provide solutions that increase customer business value and maximize the efficiency of business operations such as costs. In this paper, we will discuss "L-shape side gate automatic opening and closing technology" of the Micro PBV. In particular, we will deal with high durability opening and closing technologies that can improve the operation rate of PBVs and technologies that increase cargo space.

Damping Performance of Bolted Structures Including Plastic Members

Keisuke Inoue･Tristan Samuel Britton (Fujimori)･Yoshinao Kishimoto･Yukiyoshi Kobayashi･Shogo Isobe･Satoru Kuga･Yuuki Kawaharabashi (Tokyo City University)

Resin materials such as ABS resin are used in interior and exterior parts of automobiles to ensure vibration absorption and impact resistance. In this study, hammering tests were conducted to clarify that the damping performance of a structure with bolted resin members is determined by the superposition of viscous damping of the resin and frictional damping between the members, and finite element analysis was used to investigate the ratio of viscous and frictional damping.

Novel AD/ADAS Virtual Validation with Integration of LLM and Digital Twin Technologies

Prof. Dr. Reza Rezaei･Dr. Alexander Bradler･Dr. Christian Lang･Yassine Neifer･Carsten Simon･Thorsten Scheibe (IAV)

This paper showcases a novel AI-driven method that understands natural language requirements and scenario specifications and videos to create high-fidelity simulations, thereby automating creation and modification of scenarios for enhanced AD/ADAS virtual validation. It comprises three key components: generating simulation models from textual inputs using an adapted large-language model (LLM); extracting scenarios from real test videos using visual LLM, including detection of corner cases like glare and camera soiling; and enhancing criticality with multi-agent approach. The results will be presented for above-mentioned use-cases, covering the spectrum from ADAS to full AD, including co-simulation of different tools based on JAMBE model connection. An assessment of the approach for efficiency enhancement along with an outlook will be provided.

Building trust in collaborative simulations

Henri Sohier･Romain Barbedienne (IRT SystemX)･Julien Silande (ESI)

Collaborative simulations often suffer from organizational silos, hindering trust due to challenges in information exchange about both the simulation and the system it represents. Capturing, controlling, and communicating critical data throughout the development cycle -from specification to validation- requires structured solutions. This paper proposes clear requirements and practical tools to address these challenges. Factors such as the decision-making context, barriers between stakeholders, and their varying levels of technical expertise are carefully considered. Our approach fosters confidence among stakeholders, with a particular focus on the automotive industry, where effective collaboration is crucial to managing system complexity.

Simulation verification and validation: the challenge we all face

Henri Sohier･Romain Barbedienne (IRT SystemX)･Julien Silande (ESI)

Simulation Verification and Validation (V&V) spans a wide range of subtopics and approaches, with nuanced distinctions in system engineering, software engineering, and simulation engineering. Recognized standards, such as those by NASA and NAFEMS, encapsulate various existing practices. V&V is critical to building trust, ensuring credibility, and maintaining quality in simulations and simulation architectures. This article examines methodologies and tools designed to optimize current best practices while fostering effective communication about V&V processes, addressing key challenges in achieving trustworthy and integrated simulation frameworks.

Systems Engineering Initiatives for Promoting MBD

Yuki HIRAYAMA･Takuya MACHIDA･Hironori YUMURA (SUBARU)

Development of automobiles is getting more advanced and complex with increasing demands of CASE and new area. MBD is expected to reduce prototyping period and costs. Many models are built with MBD in the automotive domain; however, there are many issues in the establishment of MBD processes. One of the difficulties is the process changes associated with replacement of prototypes by models. This paper reports our trial not to change existing processes in prototypes. We validated the process from digitalized requirements definition to verification using the framework of the ISO/IEC/IEEE 15288 system lifecycle processes. By applying MBSE and MBD to the existing requirements definition to prototype vehicle production process, we expanded the decision-making domain.

Model-Based Development of Damper Properties and Vehicle Dynamics Performance through Model Exchange between OEM and Supplier
-Development of Real-Time Damper Model and Use of OEM Vehicle Model for In-House Development-

Peng Lu･Hiroshi Endo･Shuta Suzuki (Astemo)･Yukihiro Adachi･Shunsuke Iwamatsu･Toshikatsu Hoshi･Kazuo Mori･Mitsunori Makino (Toyota Motor)

Model Based Development methods have been widely used in the automotive industry. The development of damper components, which traditionally relies on subjective evaluation like handling and ride comfort in an actual vehicle. However, damper MBD development is still considered difficult for subjective evaluation index and highly accurate vehicle model. To improve these by close model collaboration and use a detailed damper model and simulator from the early stages of development between OEMs and suppliers. We developed detailed damper models which can calculate real-time for simulator. Also, we studied to use OEM vehicle models for in-house damper development efficiently.

Model-Based Development of Damper Properties and Vehicle Dynamics Performance through Model Exchange between OEM and Supplier
-Study of Vehicle Dynamics Evaluation Using Driving Simulator-

Yukihiro Adachi･Shunsuke Iwamatsu･Toshikatsu Hoshi･Kazuo Mori･MItsunori Makino (Toyota Motor)･Hiroshi Endo･Peng Lu･Shuta Suzuki (Astemo)

It is expected that model-based development, collaborated between suppliers and OEMs from the early development phase, can improve product quality and prevent development rework. In this study, we focused on dampers and created a co-simulation environment for evaluating vehicle dynamics performance, exchanging models between companies. Handling and ride comfort evaluations were performed using a driving simulator, and obtained results were consistent with actual vehicle tests and offline simulations.

Synergies of Developing and Testing Battery Management Systems (BMS) in SIL and HIL Environments

Katsuya Tsuzuki (dSPACE Japan)･Fabian Bronner･Thomas Paradowsk (dSPACE GmbH)

This paper presents an architectural design for the V-ECU aimed at shifting the development and testing of BMS from HIL to SIL. The primary objective is to enable the reuse of tests for both HIL and SIL environments. This is achieved by virtualizing the communication between the BMC and the CSC, which typically utilize the SPI interface. By simulating SPI communication, the behavior of the ECU can be tested virtually, ensuring that existing tests remain unchanged. Additionally, SIL testing can be seamlessly integrated into a CI/CT pipeline, facilitating streamlined and cost-efficient development and testing of both new and existing BMS.

Improving e-Axle System Development Efficiency through MBSE/MBD Integration and Generative AI (LLM) Application

Masaru Katsuki･Kazunori Kawashima･Takuro Kawasumi (JATCO)･Jyunji Kashitani (Panasonic System Design)･Shota Sato (Lightblue)

"As thermal management becomes increasingly critical in electric vehicles, improving the quality and efficiency of e-Axle system development, including thermal system considerations, has become a crucial challenge. This presentation reports on practical examples of design support through the implementation of MBSE, its data integration with MBD, and the application of knowledge graph conversion of MBSE models combined with generative AI (LLM) technology."

Groundwork Toward the Inaugural AI Formula

Issa Omura･Masaya Okada･Yuki Akimoto･Kota Sakazaki･Atsushi Kato･Yuji Yasui (Honda R&D)

In light of the increasing industry demand for autonomous driving and AI technology in recent years, SICE and JSAE are introducing the AI Formula technical challenge wherein student teams will compete in their design of a fully autonomous driving system. The AI Formula challenge provides an excellent opportunity for rising engineers to acquire the skills and technology necessary for next-generation mobility research. This paper details our groundwork toward the inaugural AI Formula.

Vision-Based Control for Autonomous Driving Systems in AI-Formula

Shogo Hoshino･Akito Nemoto･Phearamony Phan (Gunma University)･Shunsuke Tarui･Akichika Kurihara･Yuki Asaga･Takahiro Oinuma･Yuji Komoto･Ryuki Kondo･Tatsuki Note (Kogakuin University)

In the AI-Formula project of Honda Research and Development, we are conducting research and development of an automatic driving system. In this presentation, we will explain the details of the information acquisition process using cameras and the control methods applied to it. Future research issues and prospects will also be discussed.

Optimization of price plan for a smart satellite city with price sensitivity considered

Shota Zenke･Zhenlong Wu･Takehito Kobayashi･Wenjing Cao (Sophia University)

Due to the declining birthrate and aging problem, there are concerns about future shortage of transportation options. In this study, aiming for continuous operating of mobility services using EVs, we introduced price sensitivity into a smart satellite city simulator and calculated the base fee and distance fee that maximize annual revenue using dynamic programming. Simulation results showed that taking price sensitivity into account leads to increased revenue.

Exploration of Solutions for the Benchmark Problem of Autonomous Emergency Avoidance through Multiple Approaches

SIYANG XIE･TAKAYASU KUMANO･YUJI YASUI (Honda R&D)

Autonomous emergency avoidance systems play a crucial role in establishing a safe driving environment. In this study, we developed a benchmark problem based on predefined autonomous emergency avoidance scenarios. Multiple research teams devised solutions using their unique approaches, which were compared and evaluated in a competition format. The evaluation results are presented, and the effectiveness of each approach is discussed.

Polynomial regression-based vehicle trajectory tracking control with vibration suppression

Kazuki Ogawa･Takeru Goto･Kosuke Toda (Honda R&D)

This study proposes a control system of vehicle trajectory tracking by calculating the steering angle using polynomial regression. To improve tracking stability, the evaluation function of the regression model incorporates suppression terms for steering angle velocity and acceleration, as well as an L2 regularization term. We compared our method with general model predictive control and demonstrated its effectiveness in reducing computation time and deriving practical tracking accuracy through computer simulations. Furthermore, we validated the method with real vehicle experiments.

Relationship between Evaluation of Elderly Drivers Urban Driving by Driving Instructors and Cognitive-Physical Characteristics and Driving Attitudes.
-Study on Driver Characteristics for Delaying Driving Cessation(44)-

Takashi Yonekawa･Masae Kojima･Hirofumi Aoki (Institute of Innovation for Future Society Nagoya University)･Kan Shimazaki (Kindai University)･Rin Itou (Institute of Innovation for Future Society Nagoya University)･Satsuki Yamauchi (Nagoya University)･Sueharu Nagiri･Kunitomo Aoki･Akio Hirano (Institute of Innovation for Future Society Nagoya University)

The increase in the number of traffic accidents involving elderly drivers has raised the issue of age-related decline in driving ability. Driving instructors evaluated the driving ability of 141 elderly drivers aged 59 to 88 years old in urban areas. The results showed that there was a correlation between the instructors' overall driving evaluation scores and cognitive and physical characteristics and driving awareness.

Evaluation of Awakening Effect and Accident Risk of Conversations Considering Driver Acceptability

hideyuki ohashi･yuji matsuki (Fukuoka Institute of Technology)

Talking while driving has been shown to enhance alertness, making it a potential measure to prevent drowsy driving. However, research on its impact on driver acceptability and accident risk remains limited. This study comprehensively examines accident risk, arousal effects and acceptability to propose an optimal approach to the frequency and content of conversations during driving.

Developing an Integrated Driver Model for Risk Assessment
-Reproduction of driver’s Visual and Cognitive functions-

Miki Hayashima･Yuji Matsuki (Fukuoka Institute of Technology)

To assess driver’s risk of traffic accidents quantitatively, we propose an integrated driver model incorporating visual and cognitive functions closely resembling human characteristics. The model reproduces the process from visual information acquisition to driving operation, accounting for human-specific perception and judgement ambiguities. By simulating driving behavior precisely, this approach enables a realistic and versatile evaluation of traffic accident risks across diverse scenarios.

Actual Status of Frailty, Driving Experience, and Safety Needs of Elderly Drivers
-Study on Driver Characteristics for Delaying Driving Cessation (45)-

Shunji Taniguchi･Aiko Inoue･Hiroyuki Umegaki (Nagoya University)･Naoshi Koide (Osaka University)･Masae Kojima･Hirofumi Aoki (Nagoya University)

In order to clarify the actual situation of elderly drivers' frailty and driving experience (driving skills, safe driving skills, and near accidents), as well as the demand for safe driving skill diagnosis/learning programs and safe driving support equipment for elderly drivers, we conducted a survey on driving cars on a daily basis. We report the results of a questionnaire survey conducted among elderly drivers (2,069 people aged 60 and over).

Relationship between Driving Risk Assessment Using Touch Panel Display and Driving Risk Estimated from Image Analysis

Masumi Terayama ()･Masayuki Shimizu･Hiroyuki Aoki (Nagoya Univ.)

It is thought that the driver perceives the change in the driving environment while driving and feels it as a risk.
Based on this hypothesis, we report the relationship between the points pointed out in the driving risk assessment test using 3DCG using a touch panel display and the points of change in the optical flow of the images.

Development of Abnormal Driving Detection Methods

Norimasa Nakamura･Masaki Yamaoka･Minori Yamataka･Takafumi Ito (DENSO)

To reduce traffic accidents, we are developing technology to detect abnormal driver driving. In this paper, we report a method for detecting abnormal driving using data collected from a driving simulator and an actual vehicle.

A Study on the Utilization of Virtual Reality in the Development of Automotive Visibility Performance
-A Comparative Study of Virtual Reality Evaluations and Actual Vehicle Evaluations-

Kazumasa Onda･Takuma Yamazaki･Yukihiro Takatsu･Hidenori Horita (Suzuki Motor)

In recent years, the use of virtual reality (VR) in automotive development has been on the rise.　Although VR is expected to be compatible with the evaluation of visibility performance, which relies heavily on drivers' subjective perceptions, there are reports suggesting that these perceptions may differ between VR and real-world contexts. Therefore, we conducted a comparative study in which general users assessed the same vehicle in both VR and real environments.

Brain Function Analysis in Vibration Compensation of HUD Virtual Image

Hikaru Kato (Niigata University)･Masaki Katagiri･Tadashige Makino･Naoyuki Shiraishi (NIPPON SEIKI)･Atsuhiko Iijima･Junichi Hori (Niigata University)

To compensate for the shake of a Head-Up Display (HUD) virtual image caused by vehicle vibrations, a vibration compensation function has been developed. The shake of the virtual image may cause discomfort to the driver. The purpose of this study is to clarify the effects of the vibration compensation function on the driver by electroencephalogram measurement. To evaluate the effectiveness of vibration compensation function, alpha and beta waves before and after driving were analyzed.

Eye Movement Analysis in Vibration Compensation of HUD Virtual Image

Maria Ono (Niigata University)･Masaki Katagiri･Tadashige Makino･Naoyuki Shiraishi (NIPPON SEIKI)･Junichi Hori･Atsuhiko Iijima (Niigata University)

To compensate for the shake of a Head-Up Display (HUD) virtual image caused by vehicle vibrations, a vibration compensation function has been developed. Vehicle vibrations also cause the driver's head movement, triggering a vestibulo-ocular reflex to stabilize gaze. In this study, eye movements were measured to evaluate the effectiveness of the vibration compensation function, and the time interval between vehicle vibrations and the vestibulo-ocular reflex was analyzed.

Quantitative Evaluation of AR-HUD Annoyance Using a Gaze Estimation AI model

Yucheng Zhang･Masataka Kato･Koichi Emura (Panasonic Automotive Systems Co., Ltd.)･Eiji Watanabe (National Institutes of Natural Sciences, National Institute for Basic Biology)

Augmented Reality Head-Up Displays (AR-HUDs) are developed with the aim of reducing eye movements but may potentially cause annoyance to drivers depending on the displayed content. In this study, we propose a method to quantitatively evaluate this annoyance using an AI model that mimics human gaze. Experimental results (N=8) showed a 66.7% agreement with subjective evaluations, suggesting the potential to replace traditional subjective methods.

Vehicle behavior evaluation by vestibular surprise model

Keita Teshima･Daichi Sato･Hidekazu Ishii･Kazuhiro Takemura･Yoshihisa Okamoto･Hiroko Kajikawa･Masayuki Watanabe (Mazda)

To extend the model-based development from vehicles to diverse passengers, we have created a new human model for vehicle behavior evaluation based on the mechanisms of vestibular perception. The model includes an algorithm called "surprise" which we have used previously for field of views for drivers and noise, vibration and harshness (NVH). We found that the model quantified the improvement of estimated susceptibility to motion sickness from Mazda's 6th to 7th generation product group. Furthermore, it could possibly explain vestibular phenomena, including the vulnerbility of children to motion sickness and the aging of balance sense in the elderly.

Concisely Measuring Cognitive Workload of the Interactive User Interface (Second report)

Hiroshi KISHI･Hirofumi AOKI (Nagoya University)

ISO17488 has been settled to measure cognitive workload when the driver uses interactive user interface. But this ISO contains two problems when we utilize it for HMI development. Those are degrees of facility of measuring, and detectivity of the light cognitive workload.
The modification to solve these problems and to complement this ISO is developed. The new measuring methods and the original ISO17488 are compared, and results are reported, in the context of measuring light cognitive workload .
Furthermore, consistency of the result when cognitive workload is measured repeatedly (the effect of habituation) is also reported.

A Study on the change of bio-signals under driver stress

Yoseob Lee･Baekhee Lee (Hyundai Motor)･Gwanseob Shin･Donghyun Song (UNIST)

This study examined the effects of automobile seat comfort functions heated system, ventilation, and massage on driver stress during highway driving. Bio-signals, including heart rate variability, skin conductance, and respiration rate, were measured using non-invasive sensors from 20 drivers under varying seat settings. Results showed that changes in seat functions were detected with over 60% accuracy through high-frequency power of heart rate variability, mean skin conductance level, and mean respiration rate. These findings suggest the potential for monitoring seat comfort using bio-signals. Further research is needed to enhance detection accuracy under diverse environmental and driver conditions.

Long-range and High-resolution Automotive LiDAR System based on a Stacked SPAD Depth Sensor

Shunpei Suzuki･Takahiro Kado･Ibuki Fujioka･Koji Yamamoto･Shengchao Zheng･Seiya Kaito･Tatsuya Yui･Gyongsok Song･Tomoyuki Taguchi･Taro Beppu (Sony Semiconductor Solutions)

As Advanced Driver Assistance Systems (ADAS) and autonomous driving progress, the demand for LiDAR systems that accurately detect road conditions, vehicles, and pedestrians, even at long distances, is growing. This study presents an automotive LiDAR system that uses a high-sensitivity, stacked SPAD depth sensor. The system achieves long-range detection of up to 300 meters at 10% reflectivity, has a wide field of view (H120° x V25.6°), and high resolution (H0.1° x V0.05°), while allowing the simultaneous acquisition of NIR images with a maximum resolution of 1200×1536 pixels.

Automotive towards SDV - Challenges and opportunities in ADAS&AV features

Xavier Sellart Ortega (IDIADA Automotive)

The automotive industry is rapidly transitioning toward era of SDV's. Bridging the gap between research and current development in ADAS involves translating cutting-edge research findings into practical, scalable solutions. This process requires close collaboration between academia, industry, and regulagory bodies to ensure that emerging technologies are effectively into real world applicaitons. By fostering collaboraiton, sharing knowldege, and investing in robust testing and validation processes, we can accelerate the adoption of advanced ADAS features, enhancing safety and efficiency on the road.

Trustworthy Multimodal Generative AI for ADAS Development

Son Tong･Balakrishnan Ayyanar･Shiye Fang･Kohei Noma･Satoshi Sekine･Theo Geluk･Reiji Takeuchi (Siemens Digital Industries Software)

Generative AI (GenAI) is a powerful technology that learns patterns from data and generates new content, with recent prominent examples of ChatGPT and other large language models (LLMs). This work discusses Multimodal GenAI technologies to accelerate ADAS development involving autonomous driving scenarios and realistic image/video data generation. We use human intelligence, engineering abstraction, and safety requirements as inspiration for trustworthy GenAI models. First, we develop GenAI to reason logged dataset and automatically extracting critical scenarios. Second, methods to generate consistent, controllable, and realistic novel traffic videos will be shown. Finally, we incorporate ADAS standards (EuroNCAP/ISO) to generate simulation-based test cases.

Tractor Driving Simulator for Agricultural Smart Safety

Kenshi Kenshi Sakai Sakai (Tokyo University of Agriculture and Technology)･Masami Matsui･Takahiro Tamura (Utsunomiya University)･Watanabe Masahisa (Tokyo University of Agriculture and Technology)･Keisuke Kazama (Nihon University)･Hidehiko Inoue･Hiroki Takimoto･Ichiro Harada (NARO)･Yuya Aoyagi (Rykyu University)･Pongsathorn Raksincharoensak (Tokyo University of Agriculture and Technology)

Fatal accidents in agriculture are 10 times more frequent than occupational accidents, with tractor rollovers being the leading cause. Strong nonlinearity in the tractor-terrain system causes dangerous behavior. Tractor design, road and field design aim to maximize yield and profit. The tractor driving simulator we developed has been shown to be effective in incorporating "safety" into these design.

Advanced Safety Technology Evolution Its Traffic Accident Reduction Analysis(Third Report)

Hasegawa Takashi･Yukiko Sanda･Yukihiro Ikeda (Toyota Motor)

Using three years of ITARDA accident data, the accident rate of the third generation Toyota Safety Sense installed in Toyota and Lexus vehicles is calculated and compared to vehicles without the system. The results confirmed that overall fatal and injury accidents were reduced by half. In particular, there was a reduction of about 90% in rear-end collisions with other vehicles, as well as a reduction of about one-third in newly addressed straight-cross-path collisions.

Analysis on Crossing Collision in Stop Intersection by Utilizing Drive Recorder Video Images

Raksincharoensak Pongsathorn･Yoko Hojo･Xingguo Zhang･Masami Aga (Tokyo University of Agriculture and Technology)･Shotaro Yamasaki (Aioi Nissay Dowa Insurance)

The objective of this research is to analyze accidents involving four-wheeled vehicles at stop-and-go intersections based on 15-second video recorded by drive recorders towards the purpose of the development of a next-generation driver assistance system to prevent intersection accidents. In this presentation, the analysis of the conditions under which accidents occurred is conducted and described, as well as the analysis of speed patterns and driver reaction maneuvers when passing through intersections.

Behavior comparison between taxi drivers and ordinary drivers in car-to-car crossing collisions at non-signalized intersections

Masami Aga･Yoko Hojo･Raksincharoensak Pongsathorn (Tokyo University of Agriculture and Technology)･Yamasaki Shotaro (Aioi Nissay Dowa Insurance)･Nagai Masao (Tokyo University of Agriculture and Technology)

The drive recorder database of the Smart Mobility Research Center in Tokyo University of Agriculture and Technology is considered to be useful for safety assurance for autonomous vehicles. This database has been generated from taxi drivers’ drive recorder data. Therefore, in advance to commence the safety assurance study, we clarified whether taxi drivers in the database could be regarded as "competent and careful human" by comparing taxi drivers’ and ordinary drivers’ behaviors in their drive recorder data in car-to-car crossing collisions at non-signalized intersections as a specific example.

Investigation of deceleration support method by driver intervention to prevent encounter accidents on residential roads

Asuka Harada･Hitoshi Kanamori (Nagoya University)･Kenichi Yamada･Hayato Mizuma･Yasunobu Yokoi (Toyota Motor)･Yuki Yoshihara･Nihan Karatas･Takahiro Tanaka (Nagoya University)

Although communication-based driver assistance is expected to prevent accidents on residential roads, there remain concerns about dependence on and overconfidence in the system. First, the effectiveness and limitations of the alerting support for safe driving behavior guidance were identified. Next, we examined deceleration support by driver intervention as a countermeasure for drivers with inadequate deceleration behavior, and report on the speed of intervention decision making, the start and end of intervention, etc.

Evaluation of the effectiveness of a child crossing approach notification system using smartphones

Yokoi Yasunobu (Toyota Motor)･Kitahara Takeshi (KDDI Corporation)･Yasui Tomoko (Toyota Motor)･Kurosawa Kengo (KDDI Corporation)

It is known that accidents involving pedestrians and vehicles are particularly common due to children around the age of seven suddenly running into the street. To prevent these accidents, a system has been developed to notify drivers of the presence of children approaching crosswalks without traffic signals. This system transmits the location information obtained from devices carried by the children to the drivers' smartphones via a mobile phone network. With the cooperation of transportation companies and elementary schools, we evaluated the effectiveness of this system by comparing the speed of vehicles, the rate of stops, and the duration of stops at crosswalks when children are approaching, both with and without the use of the system.

Feasibility Study of a Hazard Avoidance Brake Control System Using V2N Technology

Yoshiaki Irie (Toyota Motor)･Fumiaki Ise･Yukihiro Yamamoto (Technoco Corp.)･Keita Arita･Junki Ito (SoftBank Corp.)･Dror Elbaz･Tal Lavi (Eye-Net ltd.)

With the aim of enhancing ADAS capabilities by addressing hazard detection outside the driver’s field of view, this study explores the potential of V2N technology. By utilizing smartphones as external sensors, we examine the effectiveness of V2N in improving hazard detection, the positioning performance of smartphones, requirements for cloud systems, and the current challenges involved.

A Note on the Information Provision of Hazards in Urban Areas Caused by Roadside Snow Accumulation

Chinami Fukui (Graduate School of Engineering, Hokkaido University)･Sho Takahashi･Toru Hagiwara (Faculty of Engineering, Hokkaido University)･Hidekatsu Hamaoka (Graduate School of Engineering and Resource Science, Akita University)

In urban areas of snowy and cold regions during the winter, snow accumulation along the roadside not only reduces visibility but also diminishes the sensing performance of vehicles. This study examines the effectiveness of a new information provision system designed to alert drivers to hazardous locations. These hazardous locations are where snow piles resulting from snow removal may lead to an increased likelihood of overlooking other road users.

Initial study on position estimation of surrounding traffic participants observed by vehicle with position uncertainty

Kota Watanabe･Takuma Ito (The University of Tokyo)

For cooperative utilization of information about surrounding traffic participants observed by a vehicle, it is necessary to integrate two uncertainties: the uncertainty of the vehicle's position, and the uncertainty of the relative positions from the vehicle. In this study, we propose a method to integrate these two uncertainties and estimate absolute positions of surrounding traffic participants. In the proposed method, vehicle’s position and traffic participants' relative positions are estimated by Extended Kalman Filters, and then the two estimations are integrated with considering the uncertainties. Through simulation experiments, we validate the feasibility of the proposed method.

Initial study on method of extracting potentially dangerous spots to improve machine learning model for speed decision on community roads

Yuki Sadanaka･Keita Hori･Takuma Ito (The University of Tokyo)

Machine learning model for speed decision on community roads needs to adapt to the potential risk at blind spots. In this study, we aim at improving the machine learning model for speed decision on community roads so that the model can adapt to the potential risk. For this purpose, we develop a method of extracting potentially dangerous spots by using the machine learning model and pseudo careful driving data.

A proposal for indicators of proximity and safety margin for evaluating behavioral safety of automated vehicles

Yuichi Saito･Syohei Shimotori (University of Tsukuba)･Hideo Inoue (Kanagawa Institute of Technology)

A common understanding of what indicators and how to verify the safety of automated vehicles in response to possible hazardous events is lacking. In this paper, we propose an evaluation method for behavioral safety using a measure of proximity to other traffic participants and a measure of safety margin for accident avoidance in traffic conflict scenarios, and discuss its effectiveness.

Evaluation of Exhaust characteristics and Fuel Efficiency Based on Demonstration Tests of a Hydrogen Internal Combustion Engine Hydraulic Excavator

Haru Nabata (Kanazawa Institute of Technology)･Tadashi Enomoto･Takuya Yamaura (Flat Field Co., Ltd.)･Yuki Ninomiya (Oriental Consultants Co., LTD.)･Akemi Ito (Tokyo City University)･Kaname Naganuma (Kanazawa Institute of Technology)

For the purpose of technological development of a Hydrogen Internal Combustion Engine Hydraulic Excavator, an actual machine was built and operational data was obtained through demonstration tests. As a result, characteristic NOx emission characteristics caused by the hydraulic excavator's unique operating point transition were revealed. However, the NOx values were low and showed the possibility of being below the regulation values for diesel engine hydraulic excavators of the same class without requiring after-treatment equipment during HOT operation.

Study on Argon Circulated 2- Stroke Hydrogen Engine

ZHE WANG･TAKAHARU ABE･ZHILI CHEN (Tokai University)

Argon circulated hydrogen engines have higher thermal efficiency but tend to knock. 2-stroke engines can reduce knocking because the fuel required per cycle is about half that of a 4-stroke engine. On the other hand, since the exhaust gas is circulated, the fuel loss due to scavenging and the emission of lubricating oil problems in 2-stroke engines no longer exist. In this study, an argon circulated 2-stroke hydrogen engine was proposed, and the engine performance was investigated through tests on a commercial engine.

Study on the Effect of Circulation system Pressure in an Argon Circulated Hydrogen Engine

Uta Kondo･Ryouta Kiyokawa･Zhili Chen (Tokai University)

In argon circulated hydrogen engines, the effect of supercharging can be achieved without the use of a turbocharger if the circulation system is pressurized, however, the effects on combustion and pumping losses have not been studied. In this research, the circulation system was pressurized to 100 kPa to prevent knocking and increase power output. The engine operating ranges, power output, thermal efficiency, combustion, and pumping loss were investigated.

Considerations for Maximizing the Thermal Efficiency of a Highly Boosted Port-Injected Hydrogen Engine

Shojun Rachi･Tsukasa Yamazaki･Yuhei Sakane (Kanazawa Institute of Technology)･Tadashi Enomoto･Takuya Yamaura (Flat Field Co., Ltd.)･Akemi Ito (Tokyo City University)･Ryuiti Sasaki (Riken Corporation)･Masaya Yoshioka (HOROBA, Ltd.)･Kodai Ichikawa (NGK INSULATORS)･Kaname Naganuma (Kanazawa Institute of Technology)

The hydrogen engine has a distinctive feature compared to gasoline and diesel engines, as its control settings for boost pressure, air-fuel ratio, and ignition timing cover a much wider range. In this study, aiming to maximize thermal efficiency, the effects of various control settings and their combinations on thermal efficiency were examined based on bench test results. This study reports the effects of various specifications and settings, including the compression ratio, on heat balance.

Clarification of the Mechanism of Abnormal Combustion in Hydrogen Engines (Part I: Investigation of Abnormal Combustion Location by Numerical Analysis)

Pravin Ananta Kadu･Takao Nakayama･Kei Yoshimura･Keiji Muramatsu･Takuya Kosugi･Kenjiro Nakama (Suzuki Motor)

Hydrogen fueled internal combustion engines are susceptible to autoignition which may damage engine. To investigate its cause, root cause analysis was conducted at lean premixed condition. Ignition delay time for hydrogen at different conditions was obtained from chemical kinetics simulations. 1D CFD was then used to investigate the pressure and temperature conditions of exhaust gas and engine components. Based on these conditions and shorter ignition delay, most probable causes of autoignition were judged. 3D CFD and experimental results were used to confirm this finding.

Clarification of the Mechanism of Abnormal Combustion in Hydrogen Engines (Part II: Investigation of Abnormal Combustion Location by Visualization Measurement)

Keiji Muramatsu･Satoshi Tokuhara･Pravin Ananta Kadu･Kei Yoshimura･Kenjiro Nakama (Suzuki Motor)

In the development of hydrogen engines, torque constraints and the degradation of component reliability due to abnormal combustion are problems. To clarify the mechanism of abnormal combustion, a multi-cylinder visualization engine equipped with visualization windows was constructed, and in-cylinder visualization measurements were conducted. Using the measurement results and the analysis results reported in the first report, an analysis was conducted on the locations and causes of abnormal combustion.

The Syngas Production by Biogas with Methanol through Piston Compression of Diesel Engines

Changqi Liu･Dengpei Chen･Hiromu Katou･Gen Shibata･Hideyuki Ogawa (Hokkaido University)･Ken Kawabe･Ryota Minamino (Yanmar Holdings)

Under high equivalence ratio conditions, reforming of syngas via dual-fuel combustion of a small amount of diesel and biogas is associated with the issue of high smoke emissions. This study aims to reduce smoke and improve the yield of syngas by supplying methanol along with biogas to the intake, using engine experiments and chemical kinetics calculations, and to clarify the reaction processes involved.

Development of fixed speed spark ignited hydrogen internal combustion engine for heavy duty non-road applications

Xander Seykens･Erik Doosje･Cemil Bekdemir (TNO)･Peter Wezenbeek (NPS Driven B.V.)

The paper presents an overview of key development aspects for realizing a fixed speed heavy duty SI hydrogen internal combustion engine for non-road applications requiring no NOx aftertreatment. Single-cylinder experimental research results are used to determine key engine parameters, e.g. compression ratio, and base operating conditions as input to full-scale engine hardware definition. Measures to optimize performance and safeguard operational safety, e.g. misfire detection and prevention of hydrogen slip, are discussed. Engine emissions and power performance characteristics are presented for stationary operation and load steps demonstrating the STAGE V engine-out NOx emissions over diesel-like load range with acceptable dynamic response.

Research and Development of Hydrogen Engine Systems Based on Industrial Engines

Kota Tanaka (Toyota Industries Corporation)･Kohei Kuzuoka (AIST)･Hiroshi Yamamoto (Diamond & Zebra Electric)

A hydrogen engine was developed by converting the fuel supply system of a mass-produced LPG engine to accommodate hydrogen, with the goal of achieving carbon neutrality for industrial engines. To address the torque reduction resulting from the conversion to a hydrogen engine, turbocharger was added, along with abnormal combustion suppression technologies and hydrogen concentration reduction technologies in the crankcase. Minimal system modifications enabled the achievement of power performance equivalent to the base engine as well as ultra-low NOx emissions.

Research on Abnormal Combustion in Hydrogen Engines
-Construction of Knocking Prediction Model-

Hiroki KAMBE (Toyota Industries Corporation)･Ryo MASUDA (Toyota Central R&D Labs.)

A knocking prediction model for hydrogen combustion was developed and integrated into a 1D simulation to understand knocking occurrence and its factors. The model was validated using engine measurement data. It included an ignition delay database accounting for EGR ratio and NO concentration effects. Validation confirmed that using the Livengood-Wu integral value of one, it’s possible to predict knocking by the in-cylinder combustion threshold. The study revealed that the NO concentration in the EGR gas significantly affects the ignition delay time in hydrogen fuel, highlighting its importance in the knock model.

AUTOSAR Activities for Realizing SDV
-Software architecture for High Performance Computer in Vehicle-

Masahiro Goto (AUTOSAR)

In the 2nd report, the overview of software architecture of the SDV is shown with various standardization activities point of view. In this report, we discusse the configuration of in-vehicle high-performance computers and the technologies required to realise them.

Improvement of Multiple Service Metrics in Autonomous Driving Mobility by Model Predictive Control

Teppei Saitoh･Noriyasu Hasejima (Hitachi)

An autonomous driving mobility solution that can improve multiple service metrics using Model Predictive Control (MPC) is developed. This research shows a driving control method, which prioritizes the improvement of metrics expected to decline by sequentially adjusting the prediction horizon in the MPC according to the number of assigned travel destinations.

Verification of model using reinforcement learning for autonomous driving in urban area

Katsuo Semmyo･Shin Sakamoto･Masahiko Watanabe (NTT DATA Automoviligence Research Center)

Our study aims to obtain a driving model for automatic driving in urban areas with various traffic participants, such as cars and pedestrians, by reinforcement learning in an abstracted representation space. In this report, we describe our research and development efforts to apply the obtained models to a real driving environment (driving simulator).

Technology to support improvements of advanced driver assistance systems using a multimodal large language model with in-vehicle camera images

Masafumi Tsuyuki･Zhiyuan Luo (Hitachi)･Taminori Tomita･Yoshitaka Atarashi (Hitachi Astemo)

Technology that extracts desired scenes from in-vehicle camera images without visual confirmation is necessary for the efficient improvement of advanced driver assistance systems. In this study, we propose a technology that supports visual confirmation using a multimodal large language model. The evaluation results showed that the proposed method could extract half of the false positive and false negative scenes for the lane change judgment function with visual confirmation of approximately 20% of all data. This result means that the proposed method can lead to more efficient system improvements.

Measurement of Reflection and Transmission Coefficient of Snow for Camera, LiDAR, and Millimeter-wave Radar.

Yoshihisa Amano･Hiroshi Kuroda･Aiko Hibino･Masashi Mizukoshi･Hideo Inoue (Kanagawa Institute of Technology)･Kengo Sato (2309107)

Implementation of autonomous driving in 100 locations nationwide by 2027 is going. One-third to one-quarter of Japan's land will be snowy area. Our DIVP project has developed a simulator to verify the safety of autonomous driving in a virtual world rather than in the real world. In this study, we measured the reflection and transmission coefficient of snow for cameras, LiDARs, and millimeter-wave radars. For LiDAR, fresh snow was a homogeneous Lambertian reflector, and on the other hand, frozen polished "ice rink" like snow showed strong specular reflection. For reflection coefficient for radar, we found that measured curve of fresh snow and theoretical curve of relative dielectric constant of 1.4 match well. For the transmission coefficient, we found multiple reflections along thickness, which we have never seen in previous literatures, and in order to measure such extremely ne multiple reflections, we propose a unique method with a tilt snow sample.

Study of Connected Autonomous Driving in Snowfall Environment Using Optical Fiber.

Fumihito Yamaguchi (SUBARU)

In order to perform automated driving in places where GNSS signals cannot reach or to capture vehicles other than connected cars, it is important to link with information held on the road infrastructure side.
By laying optical fiber on the road, the running load of a moving vehicle can be detected and measured in terms of strain, vibration, and temperature distribution.
We have developed a cooperative automatic driving system using optical fiber sensing technology that enables real-time analysis of vehicle running conditions and road conditions, and we report on the details of the system.

Enhancing Accuracy of Multi-Camera BEV Perception using Stereo Disparity

Shuntaro Tsuchiya･Yui Tanaka･Takeru Ninomiya･Hideaki Kido (Hitachi)･Kota Irie･Yoshitaka Okuyama (Hitachi Astemo)

Development of BEV　(Bird Eye View) model that integrates multi-camera images in a bird's-eye view space is in progress. However, image-based recognition is still challenging due to low ranging accuracy. This report shows that using the relative distance obtained by stereo matching techniques improves the accuracy of 3D recognition by BEV model.

Robust 3D Object Detection in Rain with LiDAR

Keigo Hariya･Keisuke Yoneda･Yukiya Fukuda･Naoki Suganuma (Kanazawa University)

Detecting surrounding traffic participants is essential for safe autonomous driving. In 3D object detection with LiDAR, false-positive objects caused by rain splatting noise lead autonomous vehicles to unsafe path planning. This research proposes robust 3D object detection method against false-positive objects to rain splatting noise.

Implementing Localization Using Deep Learning with LiDAR Point Clouds

Kengo Kawahara･Keisuke Yoneda･Ryo Yanase･Amane Kinoshita･Naoki Suganuma (Kanazawa University)

To achieve safe autonomous driving, self-localization is essential. This study proposes a matching method that retains the features of LiDAR point clouds in a Pillar structure and converts them into pseudo-images, using deep learning to estimate the vehicle's position as a likelihood distribution. The proposed method aims to achieve more robust localization compared to conventional point cloud matching methods.

Simulation of Infrastructure LiDAR Using CARLA and Pedestrian Detection

Riku Nikaido･Keigo Hariya･Keisuke Yoneda･Naoki Suganuma (Kanazawa University)

LiDAR is widely used in autonomous driving perception and as an infrastructure sensor in urban environments. In this paper, we simulate a stationary LiDAR system specialized for pedestrian detection using CARLA. As a detection method, we leverage multi-frame 3D point clouds for object detection. Furthermore, the study aims a robust detection model capable of accurately identifying pedestrians in sparse point cloud data.

Development of ultrasonic transmission simulation to predict the effect of sonar false detection

Motoyasu Ukai･Takaaki Nakamura (Aisin)

High-precision sensing technology is essential to realize autonomous driving and autonomous parking. AEB (Automatic Emergency Braking System) detects obstacles using ultrasonic sonar, but false detections occur due to the influence of surrounding vehicle parts. In this study, we report on our efforts to develop CAE technology that can predict sensor signals when installed in a vehicle and judge whether they are good or bad.

Improved durability of FSW tools using coating technology

Sarina Shibata･Ryu Yoshiura･Souichiro Nishino (Ibaraki University)･Yukitaka Sumiya (Japan Coating Center)

Friction stir welding (FSW) has been widely applied to aluminum alloys as a joining technology with low distortion. On the other hand, improving the life of FSW tools has become an issue, and various materials and shapes have been investigated. In this study, we attempted to improve tool life by applying PVD coating technology, which is widely used for tool steel, to FSW tools.

Effect of Welding Speed on Resistance Seam Welding of Stainless Steel Foil Material

Tomoki Ohtsuka･Shion Koyama･Souichiro Nishino (Ibaraki University)･Seiya Yoshikawa (ART-HIKARI)･Tetsuya Nogami･Reina Araya (NOGAMI)

The use of stainless steel foil material is being considered to achieve both thin-wall and lightweight designs in battery systems. In this study, resistance seam welding was performed on stainless steel foil materials ranging from 200 μm to 20 μm to investigate the effect of welding speed on joint strength and fracture morphology.

Multi-scale CT observation of Al-adhesive interface during tensile test

Takanori Itoh･Masayuki Inaba･Chulho Song･Emi Mukai･Takashi Kumamoto (Nissan ARC)･Akihisa Takeuchi･Masayuki Uesugi･Yuki Sada (SPring-8/JASRI)･Hiro Fujihara･Hiroyuki Toda (Kyushu University)

Using the synchrotron X-ray multi-scale (μ-scale, nano-scale) CT, we observed while performing a tensile test using a piece of Al-adhesive specimen. We discussed the destruction source of the Al-adhesive specimen. For μ-CT, we study the movement of the filler until the destruction. For nano-CT, the behavior of the Al-adhesive interface, the adhesive-filler interface, and the adhesive-added interface are discussed.

Evaluation of Corrosion Resistance of Stainless Steel in Lithium-Ion Battery Environments

satoshi sampei･junichi hamada･atsutaka hayashi (NIPPON STEEL Stainless Steel)

The corrosion resistance of stainless steel was evaluated through potentiostatic electrolysis and immersion tests, simulating the environment of the cathode components and casing of lithium-ion batteries

Friction and Wear Characteristics of Stainless Steels for Brake Discs

Toshiki Yoshizawa･Atsutaka Hayashi･Jun-ichi Hamada (NIPPON STEEL Stainless Steel)･Takanori Kato･Yuiko Sakayama (NIPPON STEEL)

The stainless steel and cast iron were subjected to braking tests under varying corrosion conditions and braking loads. The appearance, friction and wear characteristics, and the amount of brake dust were evaluated. The cast iron exhibited deterioration in friction and wear characteristics and an increase in brake dust due to rust formation. In contrast, the stainless steel did not rust, and its friction and wear characteristics, as well as the amount of brake dust, remained unchanged.

Smart lightweight and performance solutions for structural parts by Tailor Rolled Blanks

Christoph Hahn (Muhr und Bender KG)･Taranjeet Singh (Mubea Japan Co., ltd)

TRB Benefit for Functional Improvement in Performance, Manufacturing, Part Integration, Design Simplification, Weight Reduction Cold Forming Tailor Hardened Technology

Development of the automobile recycling business

Mami Kimura (Nagasaki University)･Yutaka Asazuma (Hokkai-Gakuen University)

The aim of this research is to understand the current situation of the used parts business through related data, etc., and to clarify the future prospects of the industry. In this report, we will understand the distribution flow of used parts and recycled resources from automobiles through statistical data such as trade statistics and fieldwork, and show the future prospects.

Research on the performance of an air table separator in recovering valuable materials from ASR.

Takashi Furuyama･Masaru Yoshida (Tohoku University of Community Service and Science)

In order to improve the efficiency of ASR recycling, an experiment was conducted to recover valuable materials such as non-ferrous metals and glass from ASR using an air table separator, a dry specific gravity separator. Specifically, the relationship between the separation performance (Newtonian efficiency) of non-ferrous metals and glass and the table vibration frequency was investigated using ASR products of 2 mm or less as samples. As a result, it was found that the Newtonian efficiency was the highest at 52.0% at a table vibration frequency of 52.5 Hz.

The Future of Automobile Recycling in the Circular Economy: Creating New Value in Resource Recycling

Hideki Miyakawa (Veolia Japan K.K)

The latest recycling technologies and process improvement initiatives to maximize resource recycling will be introduced. Specifically, the presentation will describe innovations aimed at improving the efficiency of material recovery from end-of-life vehicles and reducing environmental impact throughout the entire lifecycle. The role of recyclers in achieving a sustainable automotive industry will be explored.

A Circular Economy Indicator for Vehicles (2)
-Estimation of the circular economy index considering the resource value and the quality of resource circularity-

Takamichi Iwata (Toyota Central R&D Labs.)･Takamichi Ueda･Yoshiro Masuda (Toyota Motor)･Kiyotaka Tahara･Mitsutaka Matsumoto (AIST)･Masashi Hara･Tetsuro Kobayashi (Toyota Central R&D Labs.)･Eiji Ishida･Mitsuru Ogasawara･Takayuki Nagai (Toyota Motor)

The purpose of our research is to propose an index for automobiles in relation to the circular economy. In our presentation, we will report on the results of the estimation of the amount of the material value dissipation by calculating the value of materials in the inflow and the value of materials in the outflow for each type of material in order to evaluate the resource circularity of automobiles.

3D Fuel Cell Simulation for Cell Design and Prediction of Performance and Durability

Takayuki Tsukamoto･Tsutomu Takayama･Keisuke Komiyama･Ippei Tsujimura･Rui Sugawara (Mizuho Research & Technologies)

The target is PEMFCs intended for FCVs. For cell design, we have developed a tool to draw flow channels on 2D canvas and evaluate pressure drop and flow rate distribution. By using this tool, we investigated the optimal flow path design. In addition, we evaluated power generation performance and degradation of the platinum catalyst under dynamic operating conditions by 3D fuel cell simulation.

Effect of high temperature operating conditions on single cell evaluation of PEFC

Ken Kagaya (HORIBA)･Hiroyuki Kanesaka (FC-Cubic TRA)･Tomokazu Sakai (Toyota Motor)･Hiroki Kusakabe (FC-Cubic TRA)

Membrane electrode assemblies (MEAs) with several specifications were characterized at elevated temperatures exceeding 120°C. For all MEA specifications, the degradation of the electrolyte membrane accelerated at higher temperatures and lower humidity levels. In the load cycle endurance evaluations, performance degradation intensified with increased temperatures and humidity.

Comparison of multi-fuel cylinder head concepts for heavy duty engine running on alternative fuels with Charge Motion Design (CMD) process

Avnish Jagdeesh Dhongde･Lukas Virnich･Max Mally･Bastian Morcinkowski (FEV Europe)･Dieter van der Put (FEV Group GmbH)･Moritz Lueckerath･Li Zhengling (TME, RWTH Aachen University)

Charge Motion Design process optimizes the design for multi-fuel cylinder heads using CFD simulations, benchmarks and burn duration correlations. These correlations are calibrated to engine data for individual fuels to yield the 0 to 50 % burn duration by analyzing the flow and turbulence in the combustion chamber. The calibration of these correlations to test data from ammonia and hydrogen blends is presented. The calibrated correlations for ammonia, hydrogen, natural gas and methanol were applied to different configurations to assess their performance and suitability for these fuels. These configurations varied in the port layout, valve orientation and charge motion.

H2 Internal Combustion Engines for Commercial Vehicles
-Increasing Power Density by Low Pressure Direct Injection-

Martin Weber･Nils Bronder･Thomas Kemski･Hein Beier･Axel Seiffert･Lorenz von Roemer (IAV)･Florian Sobek (Fraunhofer Institut)･Hubertus Christian Ulmer･Thaddaeus Delebinski (IAV)

For Commercial Vehicles, H2 Internal Combustion Engines (ICE), are of growing interest due to zero emission regulations. Within the framework of the joint project WaVe, studies were conducted on a 1.3 l H2 single-cylinder test engine. Port fuel injection (PFI) and low pressure direct injection (LP-DI) were investigated.
Focus was to achieve or even exceed the indicated mean pressure of a diesel engine at high thermal efficiency. Since mixture preparation is crucial and challenging, IAV designed spray caps for an LP-DI injector via 3D-CFD simulation. Further investigations focused on the optimization of the spark plug and the introduction of EGR.

Development of Compact Fuel Cell System with Water Cooling

Yuta Ichigo･Akihiro Inukai･Kasumi Nakajima･Akifumi Tsujimura･Kensuke Doi･Yasunari Arai (Toyota Boshoku)

We are developing a compact water-cooled fuel cell system for small mobility applications. In this presentation, we will introduce the power generation principles of water-cooled compact FC stack and the overview of the FC separator, the overview of the FC separatorfuel cell system, the details of the thermal management system, the results of the driving tests by an electric assist bicycle equipped with our system.

In-service State of Health Estimator for On-Board Battery Storage Systems (Part 4)

Kohei Maruchi･Takahiro Yamamoto･Hisaaki Hatano (Toshiba)

We proposed SoH estimation method for on-board lithium-ion batteries using operation data such as voltage, current, and temperature. This method estimates battery capacity by referring statistically to operation data from deteriorated battery cells and does not require special measurement or equipment.
In this presentation, we show that the method works even for usage other than EV such as BESS for PV-Solar from repurposing of batteries’ point of view.

Demonstrating non-destructive safety diagnosis for lithium-ion battery modules based on charging curve analysis data

Kenichiroh KOSHIKA (NTSEL)･Hideki TSURUGA (JET)･Tomokazu MORITA (TOSHIBA)･Keizoh HONDA (JET)

A non-destructive safety diagnosis for lithium-ion battery modules was demonstrated with experimental data. The charging curve analysis (CCA) was selected for estimating the internal state of the lithium-ion battery cell and the cell operating condition in a module. The safety threshold set by using CCA data was validated by thermal runaway tests for battery cells using an external heating method. The diagnosis for the module revealed not only its safety but also its discharge capacity (SOH). An output image with comprehensive information including indicators to accumulate remaining battery performance value was also displayed.

Smart Microgrid-Integrated Dynamic Fast Charging Station

Saleh A. Ali･Volker Pickert (Newcastle University)･Mohammed A. Alharbi (Taibah University)･Handong Li (UCL)

The transition to electric vehicles (EVs) faces critical challenges, including lengthy charging times and substantial infrastructure demands. The proposed Dynamic Fast Charging Station, functioning as a smart microgrid, addresses these barriers by enabling in-motion EV charging. Utilising renewable energy sources like wind and solar, this infrastructure can integrate capacitive and conductive charging technologies to support thousands of EVs daily while minimising grid dependency and environmental impact. This paper presents the system's specifications, economic viability, and sustainability advantages, comparing it with traditional charging methods. The Dynamic Fast Charging Station emerges as a breakthrough technology that advances EV adoption and aligns with global sustainability goals.

Modal Combination Past, Present, and Future by linkage with transportation modes with focusing on freight rail transportation

The role and share of trucks, ships, railways, and aircraft in logistics has changed due to the evolution of technology and the development of infrastructure. At a time when it is necessary to respond to global warming and the shrinking labor force, we will look from the past to the future on cooperation between transportation modes to provide sustainable logistics in cooperation with each mode of transportation rather than competition.

Research on a Method of Installing 450kW Electric Road System on Bus Rapid Transit

Hina Tamiya･Kazuki Shimamura (JARI)･Takamitsu Tajima (Honda R&D)

Nowadays, the number of Bus Rapid Transit (BRT), which change abandoned railway lines to bus routes, have been increasing. This research investigated the optimization of infrastructure and buses when introducing the Electric Road System (ERS) to BRT using dedicated routes. As a result, it was found that it was possible to balance the battery capacity and the ERS installation section.

Feasibility Study of Onboard PV for Commercial Vehicle Application
-Estimation of the Onboard Effect of PV Systems for Small Delivery Van-

Shuai Pei･Jingxuan Peng･Kimiyoshi Kobayashi･Toshio Hirota･Yushi Kamiya (Waseda University)･Hidenori Mizuno･Takashi Oozeki (AIST)

A small electric delivery van equipped with a pyranometer underwent a long-term demonstration test in Koriyama City, Fukushima Prefecture, to measure vehicle electric consumption (EC) and solar irradiance. Based on the demonstration test results, simulation models were developed to analyze the unique operational characteristics of delivery vehicles. The analysis also considered the effects of solar altitude, temperature, and seasonal variations on EC and photovoltaic (PV) generation. Furthermore, the models evaluated the energy-saving benefits of incorporating a PV system, providing insights into the potential for enhanced energy efficiency and reduced emissions in delivery vehicle operations.

Endurance test methods for batteries applied to intermittent charging during highway driving.

Yoshihisa Hojo (Toyo Denki Seizo)

Intermittent charging during driving on highrways is being considered from the perspective of reducing battery capacity and equipment-related costs for heavy trucks and other vehicles.However, this method has an impact on battery life due to frequent charging and discharging.
This paper proposes a test system using two dynamometers with a continuous rated torque of more than 6500 Nm to perform battery endurance tests on the bench.

Proof of Concept of Trolley Technology in EV Conversion of Mine Dump Trucks

Toshikazu Minoshima･Jun Ikeda･Takayuki Sato (Hitachi Construction Machinery)

The mining industry is exploring the electrification of mining dump trucks to achieve net-zero emissions.
Mine dump trucks powered by batteries instead of engines were operated at a mine with conventional trolley technology. This paper reports on the actual experiment at the mine site.

Development of a PVEV Evaluation Tool

Hidenori Mizuno･Pawita Bunme･Takumi Takashima･Takashi Oozeki (AIST)

We have developed a 'PVEV Evaluation Tool' that estimates the potential benefits of PVEVs without actual usage. This tool will provide useful information to motivate manufacturers to develop PVEVs and assist users in making decisions about adopting PVEVs.

The importance of ERS for COI2 reduction from road vehicles

Mats Alakula (Lund University)

ERS offer an alternative charging infrastructure to a fast-charging network. This facilitates a significantly reduced, or even eliminated, need for fast charging stations and a reduced need for on-board batteries. To reduce the CO2 emissions from road vehicles the sales of new EV's needs to be complemented with conversion of relatively new conventional vehicles to EV's, due to the long lifetime of conventional vehicles. Conversions allow less space for batterie, and benefit from ERS technology. The paper will elaborate on the importance of ERS technology to cap global warming.

A Numerical Analysis of Wall Heat Transfer of Diesel Spray Flame using Large Eddy Simulation with High Spatial Resolution

Tatsuya Kuboyama･Tetsu Kadohata (Chiba University)･Shin Kimura (Sustainable Engine Research Center)･Yasuo Moriyoshi (Chiba University)

This study aims to investigate the detailed mechanism of the wall heat transfer of the diesel spray flame to improve the prediction accuracy of the wall heat transfer model in engine combustion simulations. An LES analysis with fine grids aligned on the wall with enough resolution to solve the viscous sublayer without using a heat transfer model near the wall.

An Experimental Method for the Development of Vehicle Thermal Management Systems using Transient Thermal Control Devices

Hirotaka Iseki･Ryo Yoshimura･Seiji Hirai･Toshiyuki Michikita (HORIBA)

The proliferation of electrified vehicles incorporating increasingly complex thermal management systems demands more efficient approaches to developing these systems. A transient thermal control device that emulates heat sources, such as batteries and powertrains, has been used to replicate the heat exchange between the heat sources and coolant circuit based on the JAMBE thermal model. To demonstrate the applicability of the transient thermal control device for evaluating thermal management systems without physical heat sources, the reproduction accuracy of the thermal control device with respect to a model is validated; this demonstrates its potential for evaluating complex systems without full thermal systems.

Comparison of Nucleate Flow Boiling Heat Transfer on Aluminum Heating Surface Using Distilled Water, Ethylene Glycol Aqueous Solution, and Long-Life Coolant for IC Engine Cooling System

Emir Yilmaz･Takashi Suzuki･Kota Suzuki･Shota Ishii･Minato Suzuki･Kodai Kato･Mayu Watanabe･Mitsuhisa Ichiyanagi (Sophia University)

Understanding the relation between coolant composition and surface properties is crucial for improving nucleate boiling heat transfer in IC engine cooling. This study examined heat transfer mechanisms, including latent and sensible heat transport, and bubble dynamics, using distilled water, ethylene glycol aqueous solution (EG50%), and LLC under flow boiling conditions. Results revealed that due to corrosion bubble nucleation was reduced for distilled water and EG50% coolants, while LLC preserved surface wettability and bubble behavior. Increased coolant viscosity and surface wettability influenced latent and sensible heat transport, offering insights into optimizing coolant formulations and mitigating corrosion effects for improved cooling performance.

Development of a Compact Rankine Cycle Generator with an Integrated-Component Structure
-Eighth Report: Metallization of Parts and Experiment with Refrigerant-

Katsuyuki Tanaka･Chigusa Nakagawa･Tetsuhiro Wakiyama･Nana Tonooka･Kenya Ohtsuka (Nihon Univ.)

We are developing a compact Rankine cycle generator with an integrated-component structure to convert waste heat from automobiles into electricity. We will report the parts made of metal and experiment results using a refrigerant.

Energy Recovery Experiment Using a 5kW-class Rankine Cycle Generator with Engine Waste Heat from Heavy Duty Vehicles
-First report: Construction of Experimental Equipment and Performance Test-

Ryotaro Kobitsu･Hiroki Kato･Waka Katoono･Masanari Saito･Kenya Ohtsuka･Katsuyuki Tanaka (Nihon Univ.)･Masaki Naruke･Takaaki Kitamura (JARI)

We are conducting an energy recovery experiment using a 5kW class Rankine cycle generator to convert the engine waste heat of heavy duty vehicles into electricity. We attached a commercially available 5kW-class Rankine cycle generator to the engine of a heavy duty vehicle, connected it with piping to transfer waste heat, and conducted a trial experiment. We will report on the results.

Thermoelectric Materials for Hybrid Electrical Vehicle with Lean Burn Engine

Michihiro Ohta･Philipp Sauerschnig･Kishor Kumar Johari (AIST)･Masaki Naruke (JARI)･Kazuki Imasato･Masanobu Miyata･Takao Ishida･Atsushi Yamamoto (AIST)

We have developed the Mg3(Sb,Bi)2 and Bi2Te3-based thermoelectric materials for waste heat recovery in HEV with lean burn engine. In Mg3(Sb,Bi)2, the thermoelectric figure of merit in the exhaust temperature range was successfully enhanced by tuning the Sb/Bi ratio. The mechanical properties of the thermoelectric materials were investigated through compression testing. The improvement of fuel economy in the vehicle by the developed thermoelectric materials was simulated by GT-SUITE software.

Thermoelectric power generation performance by heat recovery from exhaust gas

hiroyasu mino･satoshi someya･toshie koyama (Tokyo Denki University)

We evaluated the power generation performance of a commercially available thermoelectric module for heat recovery from exhaust gas, and found that the module could generate 2.35 W/piece at ΔT110°C. We also evaluated liquid-liquid systems, such as hot and cold water, and solid-state heat transfer, and compared the performance. The basic performance of the thermoelectric modules and the heat recovery performance from exhaust gas were summarized.

Development of evaluation techniques and investigation of generation mechanisms in vehicle exterior noise from tyres.

Kotaro Mune･Ryuichi Tanimoto (SEKISO Co.Ltd.)

Tyre noise control is a major issue for Phase 3 of the exterior noise regulation. In order to analyse this exterior noise, a towing trailer type tyre noise measuring device was manufactured and a source investigation was carried out. Next, the noise emitted from the tyres was mapped. From these results, it was found that the exterior noise could be reduced by separating the direction of sound radiation from the front and rear wheels.

Construction of PBN (Pass-By Noise) Model Using MBD (2)
-Construction of PBN model linkage to a HEV 1D system model to improvement acceleration performance-

Shinta Nakazawa･Go Endo･Hiromu Iwase･Kenichiro Ogata･Kazuya Chinda (Honda Motor)

Pass-By noise regulations are continually being strengthened, restricting ENG rotation speed to reduce noise levels. This limits the freedom to set ENG rotation speed, contrary to acceleration performance. Therefore, we investigated the construction of a Pass-By Noise model that works in conjunction with the HEV 1D system model. This will expand the freedom to set ENG rotation speed, contributing to improved acceleration performance.

A Hybrid BEM-SEA Approach to Assess and Mitigate AVAS-Induced Cabin Noise: Balancing Safety and Comfort

Robert Fiedler･Massimiliano Calloni (ESI)

Acoustic Vehicle Alerting Systems are primarily designed to comply with international regulations and enhance the safety of vulnerable road users. However, the impact of AVAS on the interior acoustic comfort of vehicle occupants is often overlooked. This study presents a hybrid Boundary Element Method and Statistical Energy Analysis approach to predict interior noise levels resulting from AVAS operation. The BEM model simulates the exterior noise generated by the AVAS, while the SEA model evaluates its transmission into the vehicle cabin, considering the effects of noise control treatments. The methodology assesses and mitigates AVAS cabin noise, balancing safety, and occupant comfort.

Fast estimation method for vehicle NVH sensitivity variation range due to component tolerances

Hiroyuki Nagashima･Satoshi Hoshika･Masashi Okuno･Shigemitsu Takahashi･Hisayoshi Matsuoka (Nissan Motor)･Hirotaka Uchimura (CDH-Japan)

In order to analyze vibration noise taking component tolerances into account, it is necessary to calculate a large number of combinations of component conditions within the tolerance range and to perform contribution analysis using statistical analysis. In this study, we report that it is possible to quickly analyze vibration and noise tolerance variations by combining a fast solution method using modal linear approximation and the probability distribution of component characteristics.

Virtual Mount Design Framework for Component-Based TPA

Domenico Minervini･Andrea Serni･Theo Geluk (Siemens Digital Industries Software)

The widespread electrification in the automotive sector introduces challenges in noise, vibration, and harshness (NVH) characterization due to higher frequency ranges and stiffer bushings. Current mount testing methodologies fail at higher frequencies due to resonances in the test rig, often requiring time-intensive setups. This work presents a novel hybrid approach using high frequency measurements to identify a parametric finite element mount model. This method eliminates the need for support structures, extending the frequency range and enabling design modifications through parametric design. Results match the accuracy of traditional methods while considerably reducing the overall effort, allowing virtual prototyping.

Operational 6 DOF contribution analysis method employing virtual point transformation
-Contribution analysis application to simple vehicle model-

Junji Yoshida･Kenta Hara (Osaka Institute of Technology)

In this study, we considered a combined method of virtual point transformation and operational TPA to understand contribution of 6 DOF input force at a point, where direct measurement is hard such as inside of a structure, to the response point. We then actually applied the combined method to a simple vehicle model and attempted to obtain the 6 DOF contribution at the center of the motor to the floor as the response point.

Evaluation of audibility of information transmission sounds using auditory saliency model

Yuki Nakatani･Naoko Yorozu･Ikuyo Ohsugi･Hisanobu Ino･Masayuki Watanabe (Mazda)

We constructed an audibility evaluation model of information transmission sounds by adding a detection algorithm for the amplitude envelope of sound to the auditory saliency model. We tested our model on information transmission sounds under in-car noise conditions, and found that it evaluated the subjective audibility more accurately than conventional sound features (e.g., sound pressure level).

Sound Quality Evaluation by SD Method for Passenger Car HVAC Noise

Hideo Takao (Sekiso Corportaion)

The sound quality evaluation of passenger car HVAC noise was performed using SD method using 13 adjective pairs of comparison. For the evaluation sound, 12 types of simulated noises and 4 types of actual vehicle HVAC noises were used. For the psychoacoustic scale, we selected loudness, sharpness, fluctuatiion strength, and roughness, and examined the correlation between each adjective pair. of comparison In addition, from the multiple regression analysis of the evaluation results, we attempted to predict the Unpleasantness - Pleasantness evaluation of the actual vehicle HVAC noise using the values of each psychoacoustic scale.

Development of Piston Slap Noise Evaluation Technology Using Engine Background Noise

Junjiro Nakanishi･Tsunehiro Mori･Masakazu Kikuchi･Ayato Yamamoto･Kazuhiro Matsuoka･Yasuhiro Nonaka (Mazda)

Piston slap noise disrupts the desirable engine sound, necessitating the development of efficient prediction methods for piston slap noise. Conventional prediction models have used piston kinetic energy and cylinder block vibrations as　evaluation indices, but these did not always correlate with auditory evaluations.In this study, an effective detection　method for piston slap noise was established using a prediction model by quantifying the protrusion amount based on cylinder block vibrations and engine background noise (masking vibration). The results showed a strong　correlation with auditory evaluations. Based on these findings, piston slap noise prediction was enabled for newly developed engines.

Subjective Ride Comfort Evaluation Based on CAE Simulation Results

Rabah Hadjit (ESI)

Ride Comfort is a key NVH target when developing automotive vehicles. This paper presents a process to perform subjective Ride Comfort evaluations in a driving simulator using CAE simulation results as input. The CAE model consists of a full vehicle finite-element model loaded with wheel center forces extracted from tests performed on a single tire test stand. The paper includes a description of the process to generate and use the simulation results in the driving simulator. This process helps reduce the reliance on physical prototypes to shorten the vehicle development time.

Next generation xEV modular platforms powered by ProteanDrive In-Wheel Motor

Stephen Lambert (Protean Electric)

This presentation delves into the development of high-performance in-wheel motors tailored for premium automotive applications. As electric vehicles (EVs) continue to gain traction in the market, the demand for innovative propulsion systems that combine efficiency, power, and integration has grown. In-wheel motors, which integrate the motor (And potentially the power electronics) directly within the wheel, offer unique advantages to allow OEMs to deliver a new paradigm in Electric Vehicles with more space, improved energy efficiency, enhanced vehicle dynamics, and critically lower cost. However, this technology also presents challenges. This presentation explores these challenges and highlights the cutting-edge solutions and design strategies employed to overcome them, offering insights into the future of electric mobility.

Optimization of laminated stacks for electrified vehicle drives

Francis van der Sluis･Benny Seitzinger･Sander de Vet･Oleg Alexandrov･Emile Kruijswijk (Bosch Transmission Technology BV)･Andreas Herzberger (Robert Bosch)

Electric motors in xEV offer power loss, power density and cost optimization opportunities.
We present a minimization of hysteresis and eddy current losses in the laminated core by combining a dedicated heat treatment and glue as a joining method. Separate and combined effects are compared to the state-of-art.
Heat treatment reduces hysteresis by stress relief. Glue bonding maintains lamination flatness and prevents eddy currents to further reduce losses. Design dependent benefits up to 20% are reported.
Lower losses improve power density and reduce thermal loads to offer higher system power output or downsizing options that can reduce system cost.

Development of coil immersion oil cooling technology to improve continuous output

Takaki Itaya･Akihito Toya･Hideaki Goto･Akeshi Takahashi (Astemo)

The e-Axle for electric vehicles need to be compact and lightweight in order to be easily installed in the vehicle and to fit in the vehicle layout. The conventional indirect water-cooled structure has a problem that its cooling performance is insufficient for the increase in loss density due to the smaller size and lighter weight. In this report, we report the results of the evaluation of elemental tests and actual machine tests of motor with the coil-immersion oil-cooled structure applied.

Impact of Advanced Control Techniques on Electromagnetic Torque Generation Using a Multiphysics Simulation

Francisco Ramiro Ulloa-Herrera･Xavier Genaro-Munoz･Javier Arturo Corea-Araujo･Carlos Moya (IDIADA Automotive Technology)

This study presents a multiphysics simulation approach for permanent magnet synchronous motors (PMSMs) using Ansys and Simulink for co-simulation and control technic analysis. The methodology involves electromagnetic force analysis, accounting for voltage harmonics induced by current controllers under various control algorithms. A PMSM for traction applications is designed using Ansys and controlled via Simulink. The co-simulation evaluates magnetic and electrical interactions under different operating conditions. This approach allows the use of the same motor drive control across platforms, reducing development time and offers insights into extending the analysis to include vibroacoustic performance for enhanced motor design.

A Review on Inverter Testing Methodologies for Electric Vehicle Industry

Xavier Genaro-Munoz･Francisco Ulloa-Herrera･Javier Arturo Corea-Araujo (IDIADA Automotive Technology)

The electric vehicle (EV) industry faces the challenge of balancing rapid technological innovation with competitive pricing. Consumer trust hinges on vehicle reliability and low maintenance. This study identifies the inverter as a critical but vulnerable part of the EV powertrain, particularly as higher voltage systems are increasingly adopted for efficiency. To accelerate development and reduce costs, testing the inverter may sometimes begin before a fully developed motor is available. This review explores practical methodologies for inverter testing, evaluating their strengths and limitations to guide engineers in creating robust setups that drive innovation and ensure reliability in EV inverter technologies.

Efficient HILS Verification Method for xEVs with electrified equipment
-- Real-time validation using causal models --

Kazuhiko Kurokawa･Kensuke Tsukahara･Yuji Yajima (MCOR)

In recent years, automobile development has become complicated due to electrification and advanced technology, so it is an efficient verification is required. This paper focuses on the HILS verification of xEV development and introduces the establishment of a real-time verification method applying causal models, along with the efficiency of verification in the MBD process, illustrated with specific examples.

Technology for optimizing pump startup in electric vehicle cooling systems

Naoki Onosaka･Takeru Yamamoto (AISIN CORPORATION)

In recent HEVs and EVs, multiple components are integrated to achieve weight reduction and cost savings. However, there is a risk of unintended rotation of the electric pump during cooling circuit switching, which can lead to startup failures. This study examines whether incorporating position-fixing logic into an externally rotated electric pump can enable rapid and proper startup.

Improving the performance of eAxles with integrated charging functions for electric vehicles

Keiya Nimura･Yoshihisa Kubota･Soumei Nakatomi･Keisuke Azusawa･Takumi Todoroki･Naoya Naito･Satoyoshi Oya (Honda R&D)

As an effort to reduce the cost and weight of electric vehicles, we have been studying the eAxle, which integrates a power converter for charging into the motor and inverter. In this paper, we present the results of our study and actual device verification of an eAxle with an integrated charging function to improve performance during motor drive and DC quick charging.

Dynamic Wireless Power Transfer for Multiple AGVs using Capacitive Coupling method

naoya kondo･Fujiyuki Iwamoto･Takayuki Shibata･Tetsuo Hirano･Takanari Sasaya (MIRISE TECHNOLOGIES)

Using a capacitive coupling method, which has a simple structure and prevents metal foreign objects from inducing heating, we demonstrated that it is possible to provide a stable power supply of several hundred watts per AGV from a single RF power source to multiple AGVs traveling within a 10-meter power supply section.

A Research for AI driven Advanced Performance Evaluation of Exterior Closure System

SOONHO HER･MINHYUNG BYUN･BYUNG SUNG PARK (Hyundai Motor)

To evaluate closure system performance in advance before PROTO/PILOT stage, data for each design parameter involved in certain system is necessary. For implication of data driven advanced evaluation within closure systems, estimation about cabin pressure rise and air bind resistance energy is required. In this paper, cabin pressure rise and air bind resistance energy occurred by slamming door, tailgate or trunk could be estimated by analysis of simple box model and statistical model calibration and validation. With this estimation process, utilizing deep learning technology would be a powerful solution for proto-less and virtual vehicle development to optimize design parameters in advance.

The Role of Interpretability in Shape Generative Models for Aerodynamic Vehicle Design

Daiki Ikeuchi･Yohei Morikuni･Mashio Taniguchi･Yuta Ito･Yuya Fukao･Yuya Yamashita･Shiro Yasuoka･Tomotaka Sugai･Koji Nishikawa･Minoru Tsuchiyama (Toyota Motor)

Deep generative models have demonstrated potential in accelerating aerodynamic design via reduced simulation cost during vehicle development. However, their practical adoption is limited by a lack of interpretability; this challenge obscures decision-making process and complicates the model integration into development workflows. Here, we introduce a technique for visualizing the influence of geometric features on the latent space of shape generative models, offering a pathway towards more interpretable and actionable generative design tools.

Tesla Cybertruck Aerodynamics - A fully automated reverse engineering methodology using 3D Scanning and OpenFOAM

Wouter Remmerie･Nikola Majksner (AirShaper)

Analyzing and understanding the aerodynamics of existing cars is key to improving the shape and efficiency of new cars. 3D scanning is commonly applied to obtain 3D models of cars, but these models pose significant challenges for CFD (computational fluid dynamics) methods - these typically require simplified and watertight models. This paper presents key aspects of a fully automated and validated workflow to analyze the aerodynamics of 3D scans without any manual efforts. The workflow has been validated against wind tunnel test data and has been endorsed by OEMs.

6 Bar Link Operation Analysis Using Multi-body Dynamics

woosik Yoon･Minsu Kim･Sungwon Hong･Jaehyun Seo (DAEDONG HI-LEX)･Kihyun Choi (Hyundai Motors Namyang Laboratory)

With the luxury of automobiles, it is developing from a general side door to a coach door. Since this coach door has a structure without a b-pillar, it requires a lot of rigidity and safety. To this end, a door hinge that can open 0-180 degrees was developed using a six-section link. In this study, the behavior of the 6bar link was analyzed with a Multi-body dynamic. Through this, the operation abnormality according to the distance between the moving pin and the fix pin was confirmed, and a system that improved this could be developed.

Consideration Regarding Drag Torque Reduction of Disc Brakes（2nd Report）

Takumi Inoue･Akinori Hirashima･Naoya Miyahara･Yuhei Yamazaki･Takashi Shimizu･Yusuke Kato (Advics)

One of the characteristics of disc brakes that contributes to fuel effi ciency and electricity consumption isdrag torque.
In this report, the effects of wind flow on drag torque are quantified by CFD analysis for the purpose of reducing drag torque in urban driving, leading to the elucidation of drag torque phenomena and prediction techniques.

Establishment of target aero drag and investment criteria considering vehicle characteristics

WOOKHYUN HAN･KWANG CHAN KO (Hyundai Motor)

The major resistance to vehicle driving energy, known as aero drag, is directly linked to fuel efficiency improvement. To achieve efficient aerodynamic performance development for xEV vehicles with a short history, it is necessary to establish the quantitative relationship between aero drag and fuel efficiency. In this study, we analyze the impact of aero drag reduction on fuel efficiency in internal combustion engines and xEV vehicles. Furthermore, we analyze the aero drag and fuel efficiency effects based on vehicle driving profiles and weights, propose target aero drag, and make decisions on the investment in various aero drag reduction-related items.

Development Of Indoor Lighting Optimization Through Customer Preference Clinic

DAESEON LEE (Hyundai Motor)

As customer demands increase, the design complexity of automobiles increases. Automotive makers have developed design methods using modular architecture method to solve this problem. In this paper, we propose a method to solve design complexity problem using axiom method and matrix visualization method. Axiomatic design is a systems design methodology using design matrix(DM) to analyze the transformation of customer needs into functional requirements, design parameters. We developed the design flow chart using DM(Design Matrix). DSM(Design Structure Matrix), representing linkages of process is also used to reduce the complexity. This approach is applied for vehicle cooling system and show the usefulness of architectural design approach.

Application of Preloaded Linear Bearings to Stowable Steering Columns for Enhanced Stiffness and NVH Performance

Herbert Erhardt･Seryas Mohammad･Matthias Beck (SCHAEFFLER Technologies)･Wenshan Tang (Schaeffler Japan)

Advancements in automated driving require stowable steering column for smooth transitions between manual and automated modes. However, the extended axial stroke needed compromises stiffness and NVH performance. This study investigates using preloaded linear bearings to maintain stiffness and NVH levels comparable to conventional steering column system.

Seat Comfort Strategy considering High Performance Vehicle Package Factors

Sunwoo Choi (Hyundai Motor)･Peter Classen･Sebastian Schumann･Thomas Schenke･Mert Kocoglu (Hyundai Motor Europe Technical Center)

In high-performance vehicles, the most important factors are acceleration performance and cornering, followed by seat position. Such seat position is the most important factor in vehicle development and is generally developed based on sitting height called H30. In addition, in high-performance vehicles, comfort performance is required, which is different from that of a typical vehicle. The seat comfort engineer should fully understand these two areas to review the package in the preceding stage and the seat specifications in the development stage. In this study, we studied the package factors to be considered when developing high-performance vehicles through benchmarking European competitors and items to maximize seat comfort. Also, Our high-performance car seat comfort has been upgraded to the next level. In addition, the specifications of high-performance seats are reflected in the Catia template to increase work efficiency.

Impact Energy Absorption and Safety Evaluation of Glass Fiber Reinforced Plastic Composite Leaf Springs for Automotive Applications

SOO SIK CHUNG (Hyundai Motor)

Glass fiber reinforced plastic (GFRP) composite leaf springs have gained significant attention as a next-generation automotive component due to their lightweight and durability compared to traditional metal springs. This study evaluated the impact resistance of GFRP leaf springs to confirm their feasibility for real-world vehicle applications, contributing to the development of safer and more efficient vehicles.

A Study on the Multifunctional Protection Bumper cover of Autonomous Driving Sensor

HONGHEUI LEE (Hyundai Motor)

This study examined the roles and functions of front bumper and grill components that have recently been changing to implement electric vehicles and autonomous driving. The development of self-healing and device technologies and sensor transmittance maintenance, which require the development of autonomous driving sensors, have been completed as basic technologies.
By removing parting that could not be implemented before, the integrated design and various patterns and colors were implemented to enhance the marketability of the exterior.
It has established standards for self-restoration of heating wires to maintain self-driving sensor performance and endure extreme environments.

Investigation of ΔV Calculation Method Considering Vehicle Rotation Behavior in Side Impact Accidents

Noboru Tanase･Shizue Katsumata･Takahiro Ando･Yasushi Nagaoka (Toyota Motor)

The calculation of the fatality and severe injury rate in D-Call Net (AACN) uses pseudo ΔV as an indicator of the severity of collision accidents. The calculation of pseudo ΔV is based on the assumption that "the impact acts on the center of gravity" and "the vehicle does not rotate." Under this assumption, approximately the same ΔV occurs in any non-deformed part of the vehicle body. Therefore, when comparing pseudo ΔV with vehicle data, the ΔV from the airbag ECU has been used. However, in accidents that deviate from this assumption, a certain degree of error may occur, potentially leading to inaccurate estimates of the fatality and severe injury rate.

Research on automatic detection of vehicle damage using deep learnig

Tetsuya Nishimoto･Kazuhiro Kubota･Kento Nakao (Nihon University)･Tomokazu Motomura (Nippon Medical School)･Martion Elsegood･Sam Doecke･Giulio Ponte (The University of Adelaide)

We have developed an image recognition algorithm that uses deep learning to determine the extent of vehicle damage based on traffic accidents that have occurred in Japan. To verify its effectiveness, we applied it to 700 EDR data and vehicle damage images collected in South Australia, and examined its practicality. As a result, we found that it can instantly recognise the extent of damage with a 70% accuracy rate.

How does pre-crash environment affect injury risk? Injury prediction and analysis based on graph neural network

JUNHAO WEI･Yusuke Miyazaki (Institute of Science Tokyo)･Fusako Sato (JARI)

Injury severity in vehicle crashes is influenced by various factors within the pre-crash environment including environment, vehicle and driver attributes, together with other pre-crash attributes. To investigates the relationships among the factors to identify key determinants of injury outcomes, this study employs graph neural network to model complex interactions and dependencies from police-reported tabular database. The analysis reveals critical contributors to injury severity, uncovering relationships among variables in pre-crash environment. These findings provide actionable insights for enhancing traffic safety and developing effective injury prevention strategies.

Investigation of Severe Injury Probability Prediction Models by Body Parts Through Decision Tree-Based Machine Learning Approach

YIMENG MEI･Haruhiro Fukushima･Yusuke Miyazaki (Institute of Science Tokyo)･Fusako Sato (JARI)

Traffic accidents result in countless economic losses and casualties worldwide annually, making reducing casualties in road accidents always been a hot topic in research. In this context, quick and accurate prediction of occupant injury severity in traffic accidents helps emergency services respond more effectively. However, previous research effects have mainly concentrated on predicting overall injury severity rather than looking at injuries to specific body parts, which limits the precision of injury assessment and targeted emergency response. In this study, we aim to develop specific Random Forest-based models to predict injury severity for different body parts, including the head, face, neck, thorax, abdomen, spine, and limbs. These models facilitate the analysis of correlations between various accident risk factors and body part-specific injuries. Furthermore, they enable emergency services to implement more precise and targeted response strategies after accidents happened.

Study on Ventilation Volume of EV in the Case of Transport for COVID-19 Patient (Part4)

Koichi Oshino (non)

Cabin ventilation is important in the case of transport for COVD-19 patients. At the previous report, it is focused on the small opening window case, and it is cleared the relation between opening window height and the ventilation volume by the simple method. Here, this method is applied to the real vehicle, it is examined the relation between opening window height and the ventilation volume.

Enhancing Vehicle Safety Through AI-based Motion Prediction and Drivable Space Estimation

Emilia Silvas･Robin Smit (TNO (Netherlands Organisation for Applied Scientific Research))･Manuel Munoz Sanchez (Eindhoven University of Technology (TU/e))･Koichi Kawaguchi (TNO Japan)

This paper presents advanced novel (AI-driven) methods for motion prediction and drivable space estimation, crucial for improving Automated Vehicle (AV) safety, comfort, and efficiency. Results from Dutch and European projects showcase techniques to anticipate crossing pedestrians and aggressive vehicle maneuvers, enhancing situational awareness. These efforts provide insights into AI model requirements and safety. Furthermore, we introduce SDS++, a drivable space estimation framework that adapts to dynamic environments using multi-sensor inputs, surpassing traditional methods. Validated with real-world data and simulations, SDS++ integrates with a model predictive control (MPC)-based planner for context-aware trajectory adaptation, significantly improving AV planning and reliability.

A Study on Natural Language-Driven 3D Styling Generation Technology for Vehicle Styling

Akihiko Katagiri･Yoshikazu Nakagawa･Shin Saeki･Jun Shiraishi･Osamu Ito (Honda Motor)

We developed a cutting-edge technology to efficiently design vehicle styling while meeting the requirements of pedestrian protection performance. By using Retrieval-Augmented Generation (RAG) technology, we built a system that enables the surrogate model to be invoked seamlessly through natural language interaction. This system can automatically generate 3D styling shapes. By incorporating this approach, the technology significantly enhances the ability to explore and evaluate numerous styling proposals with high precision during the early stages of vehicle development. This ensures a streamlined process while maintaining both safety standards and attractive design qualities.

EU landscape for safety assessment of Connected and Automated Driving

Olaf Op den Camp (TNO)

In the Horizon 2020 and Horizon Europe research and innovation frameworks of the European Commission, large projects have been defined to develop and harmonize methods for the safety assessment and safety assurance of connected and automated mobility systems. The paper will provide an overview of these projects, their results, and their relation with other international initiatives, e.g. in Japan, South-Korea and the USA. This will be put in the context of international regulations and standardization activities.

Survey and Analysis of External Factors as Challenges to the Adoption of Commercial Electric Vehicles in the Freight Transport Industry

Shota Miyoshi･Tomonori Hasegawa (NALTEC)

Expanding the commercial use of electric vehicles is crucial for achieving carbon neutrality in automobile transportation.
This study conducted questionnaire surveys targeting two groups: general freight transport companies and those already using electric vehicles, to compare their perceptions of electric vehicles and usage practices.
The findings identified external factors, such as market and technological barriers, that could impede the broader adoption of commercial electric vehicles.

Path following for low speed vehicles (3rd report)

Saoto Tsuchiya･Kirill Peljuh (FUTU-RE)

We consider how to determine turning paths and acceleration/deceleration to optimize ride comfort for automated low-speed vehicles. To optimize ride comfort, we aim to minimize the change in inertial force during turns, and in the second report we derived ordinary differential equations to achieve this.
In this report, we propose a practical optimal path and speed profile by solving the ordinary differential equations under realistic conditions.

Occupant behavior and subjective evaluation during acceleration and deceleration in electric light and low-speed vehicle (LLV)

Sueharu Nagiri･Takashi Yonekawa･Hirofumi Aoki (Nagoya University)･Yuuya Ohba･Munehiro Oosumi･Manabu Kai (YAMAHA MOTOR Corporation)

Electric light and low-speed vehicles (LLV) are widely used for green slow mobility. We measured and subjectively evaluated occupant behavior during acceleration and deceleration using LLV. As a result, we found that occupant behavior differs greatly from individual to individual. From the occupant behavior and subjective evaluation, we were able to determine the thresholds of acceleration and deceleration that should be considered when driving with LLV.

Development of a Container-Based Yocto Build System for an Infotainment SW Platform

Joonhyung Kim (Hyundai Motor)

This paper introduces a Yocto build system configured on a container for building an infotainment SW platform. The introduction raises the issue of directly configuring host environments for various platforms and versions and presents existing approaches to building Yocto on a container and their limitations. The background section briefly introduces the key concepts of Yocto Project and container technology. The main section details the techniques applied to the build system, including a layered structure using base images, managing authentication for accessing private repositories, and connecting Yocto development environments to external resources, as well as a tool for supporting build system.

Driving behavior of Careful human drivers in the scene of dynamic blind spots and overtaking a bicycle

Yuki Manabe･Toru Kojima･Koichi Kitada･Kenji Morizaki (NALTEC)

In UN Regulations for automated driving vehicles, it is required that the performance of the system shall be ensured at least to the level at which a “Competent and Careful human driver (C & C driver)” could minimize the risks. However, quantitative requirements for careful driving behavior equivalent to the "Careful" part of “C & C driver” have not been determined. In this study, the behavior of a careful human driver in situations with dynamic blind spots was investigated by using a driving simulator.

Study on Visibility Behavior at Intersections in an Actual Vehicle and an Immersive Driving Simulator

Hisato Fukuda･Yuto Takei･Hyuga Nojiri (Gunma University)･Toshihiko Kozai･Tsutomu Iwase (Gunma University / SUBARU)･Masanori Yoshida･Kenichi Sato (SUBARU)

Although immersive driving simulators are expected to be useful for evaluating driving visibility performance, it remains unclear whether visual behavior can be measured to the same extent as in an actual vehicle. This study examined drivers' visual behavior when turning right at an intersection using an actual vehicle and an immersive driving simulator. This paper focuses on changes in visual behavior caused by increased occlusion around the A-pillar and examines drivers' visual behavior in different driving environments.

Improvement of Driving Simulator for Rear-end Collision Prevention Education Using the PLATEAU 3D City Model

Koshi Miyazaki･Kazuaki Goshi･Yasuaki Sumida･Masaki Hayashi (Kyushu Sangyo University)･Katsuya Matsunaga (Kyushu University)

To prevent rear-end collisions, it is considered effective to educate drivers on maintaining appropriate inter-vehicle distances through rear-end collision experiences using a driving simulator (DS). In this study, we improved a rear-end collision prevention educational DS utilizing the PLATEAU 3D city model by adding a function to display inter-vehicle distance graph and the review function to show driving operation data.

Analysis of Mirror Field of View Expansion Range Resulting from Driver's Head Movement

Takashi Hosokawa (JARI)･Akinari Hirao (Shibaura Institute of Technology)･Tomotaka Igarashi (JAMA)

The use of a camera monitoring system (CMS) is permitted by UNECE Regulation No. 46; the CMS cannot change the field of view because the camera is fixed in position and can only change the field of view temporarily. With mirrors, the driver can move his/her head to widen the field of view. In this study, we examined the range of field of view expansion by head movement in a Class 3 mirror through an actual vehicle experiment. As a result, the angular range of about three times the legal range could be confirmed by moving the head.

Interaction between inappropriate schema and attention deficits as a mechanism of pedal misapplication

Shohei Shimotori･Yuichi Saito･Makoto Itoh (University of Tsukuba)･Toshihisa Sato (AIST)

Undergraduate/graduate students with no driving experience were given the task of following a car as well as cognitive and tactile subtasks on a driving simulator. As the students became more proficient in pedaling, several misapplications were observed. We analyzed past pedal operations in the same forward situation as the moment when the error occurred. The results suggest that the interaction between inappropriate schema activation and attention deficits might lead to pedal misapplication.

Assessment of the Impact of Drunk Driving

Masaki Yamaoka･Norimasa Nakamura･Minori Yamataka･Takafumi Ito (DENSO)

The introduction of technology to detect impaired driving (impaired driving caused by alcohol or drugs) has been discussed in US regulations and new vehicle access (NCAP). As a basic study, we collected drunk driving data using a driving simulator and an actual car, and analyzed the trend of drunk driving.

Provision of Information to Encourage Driver Preparing Behavior toward Potential Risks

Saori Noda･Taiji Kawachi･Koji Hamada (Advanced Research and Innovation Center, DENSO CORPORATION)･Hitoshi Kanamori･Asuka Harada･Takahiro Tanaka (Institutes of Innovation for Future Society, Nagoya University)

In this study, we investigate a method to make safe driving habits by making drivers take preparing behavior for potential risks by providing information corresponding to driving behavior when approaching an intersection. By the effect verification in the driving simulator, we confirmed the increase of the expected action, and it was indicated to be effective for the induction to the safe driving.

Personalization of parking styles and steering assistance for reducing discomfort with parking assist systems

Kenta Maeda･Naoyuki Tashiro･Swarn Singh Rathour･Shinji Seto (Hitachi)･Daisuke Tsuga･Hiroki Sato･Miki Koso･Atsushi Yokoyama (Hitachi Astemo)

Parking is one of the driving tasks that many drivers feel difficult. However, the parking assist system also has the problem of a low utilization due to anxiety and discomfort caused by difference from individual driver’s driving style. In this presentation, we consider a method of reducing anxiety by assisting with the driver’s manual parking operation based on haptic feedback, and reducing discomfort by using a target trajectory that is adapted to the individual parking styles of the driver.

Development of Trajectory Prediction Methods for Oncoming Vehicles and Path Planning Techniques for Narrow Road Passing by Autonomous Driving

Ryo Inaba･Masato Imai･Shuntaro Tsuchiya･DANIEL GABRIEL (Hitachi)･Hidehiro Toyoda･Satoshi Ito･Yuichi Komoriya･Ryo Sakurai (Hitachi Astemo, Ltd.)

We are developing autonomous driving technology for highways, general roads, and residential roads. On residential roads, cooperative actions with other vehicles, such as merging and passing, are necessary without wireless communication. In this presentation, we propose a machine learning-based trajectory prediction method for oncoming vehicles and a path planning method including reverse evasion. We report the evaluation results of the proposed method at the road environment modelled on residential streets.

Trajectory Planning for Lane Change Feasibility Decision Using Chance-Constrained Model Predictive Control

Yuichi Okura･Kenta Tominaga･Hiroaki Kitano (Mitsubishi Electric)

The objective of this study is to improve the decision performance for lane change feasibility by planning trajectories that consider future variations. In the proposed method, the probability of maintaining a safe distance from other vehicles is imposed as a chance constraint. In merging scenarios where the behavior of other vehicles is highly variable, the success ratio of merging improved by 30%. Additionally, the performance of the proposed method was evaluated by adapting it to a real vehicle.

Joint Research on CO2 Reduction between Petroleum Association of Japan
and Japan Automobile Manufacturers Association (AOI Project)
-3rd report-

HIDEAKI SUGANO･TAKASHI KANEKO (ENEOS)･HIRONORI SHODAI (IDEMITSU KOSAN)･TAKASHI SANO (Isuzu Motors)･TSUTOMU KIKUCHI (Nissan Motor)･HITOSHI HAYASHI･KATSUHIKO YAMAGUCHI (Toyota Motor)

The Petroleum Association of Japan (PAJ) and the Japan Automobile Manufacturers Association (JAMA) are conducting joint research (*AOI project) aimed at reducing CO2 emissions by optimizing the combination of future engine combustion methods and future fuels in anticipation of the market around 2030. This report provides an overview of the AOI project from 2020 to 2024.
*AOI Project; Automobile and Oil Innovation Project

Prediction of vehicle fuel consumption under WLTC driving conditions using AOI Project fuel in dilute/lean combustion

Yasuo Moriyosih (Chiba University)･Fuguon Xu･Zhiyuan Wang･Tatsuya Kuboyama (Chiba Univ.)･Kotaro Tanaka (Ibaraki Univ.)

In this study, the authors evaluated olefin-based fuels and drop-in fuels using a single-cylinder engine. We evaluated thermal efficiency within the range where stable combustion was possible by adding EGR and air from 0 to the maximum value.
Next, we predicted the fuel efficiency of four types of passenger cars (light vehicle N/A, light vehicle T/C, series HV, parallel HV) when the fuel was changed. As a result, it was found that fuel efficiency can be improved by adding olefin-based fuels that burn stably even when EGR or the amount of air is increased, or oxygenated biofuels that improve the octane rating. In particular, it was found that the rate of improvement in fuel efficiency is particularly noticeable in series hybrid (HV) vehicles that operate under specific load and engine speed conditions.

Propagation characteristics of pentene, ethanol, and isooctane premixed turbulent flames

Hiroshi Maeyama･Takato Kataoka･Yugo Yoshikawa･Ekenechukwu Chijioke Okafor･Toshiaki Kitagawa (Kyushu University)

Using pentene as an olefin, ethanol as an alcohol and iso-octane as a paraffin, the each single-component fuel of the turbulent flame propagation and extinction characteristics during stoichiometry and lean combustion were investigated using a constant volume combustion apparatus. It was revealed that pentene has a higher turbulent burning velocity than other fuels, and that in lean combustion, it does not extinguish even at turbulence intensities that extinguish other fuels.

A Shock-Tube Study on the Dependence of Base Fuels on Ethanol Ignition Suppression

Tomohiro Hamasaki･Ken Satokawa･Ryohei Hirai･Riku Sugiura (Sophia University Graduate School)･Kazuo Takahashi (Sophia University)･Akira Miyoshi (Hiroshima University Graduate School)

Ethanol has high performance not only as a biofuel but also as an octane enhancer. We found through shock tube experiments that the ignition suppression effect of ethanol differs when ethanol is added to base fuels with different components. The chemical interactions between ethanol and each component in the base fuels were discussed using computer simulation based on the detailed reaction model.

Laminar burning velocity of light olefin containing gasoline surrogate fuels with oxygenated fuel addition

Yuki Ito･Kento Masui･Taku Mizutani (Osaka Metropolitan University)･Fugo Kawanishi (Osaka Prefecture University)･Hidefumi Kataoka･Daisuke Segawa (Osaka Metropolitan University)

The laminar burning velocity of light olefin containing gasoline surrogate fuels with oxygenated fuel addition were measured using a spherical vessel method. The laminar burning velocity of the surrogate fuel increased with increasing 1-pentene rate in the fuel. Adding ethanol to gasoline surrogate fuels increased laminar burning velocity and adding ETBE decreased laminar burning velocity.

Fuel Property Effects of Paraffinic Fuels on Combustion and Exhaust Emissions Characteristics of a Heavy-Duty Compression Ignition Engine

Byungju Shin･Toshiaki Shinozaki･Noboru Uchida (New A.C.E Institute)

Appropriate fuel properties can be expected to improve thermal efficiency and exhaust gas emissions, compared to conventional diesel. However, the effects of each fuel property on compression ignition combustion and emission characteristics have not yet been revealed, as fuel properties react on each other and hard to be modified separately. Evaluating the effects of fuel properties separately could help in designing preferable fuels for a future carbon-neutral society. This study investigates the mechanism of combustion variation through the engine combustion and exhaust emissions characteristics with paraffinic fuels having different properties.

Effect of the introduction of battery electric vehicles on ground-level O3 and PM2.5
-Mitigation of heat island effect and health impact-

Hiroo Hata･Norifumi Mizushima (AIST)･Tomohiko Ihara (The University of Tokyo Graduate School)

In this presentation, we will show the results of the estimation of the changes in temperature due to the mitigation of UHI effect, and the changes in ground-level O3 and PM2.5 concentration after introducing BEVs to the Greater Tokyo Area (GTA) of Japan using numerical weather prediction and regional chemical transport model. The changes in premature mortality due to the changes in O3 and PM2.5 were estimated.

Effect of Fuel Tank Pressure on Air Entrainment Phenomenon During Automobile Refueling and Its Calculation Model

Shota Yokoyama･Toshiki Iwakawa･Keiki Yamaguchi･Juan C. Gonzalez Palencia･Mikiya Araki (Gunma University Graduate School of Science and Technology)

During refueling of an automobile, air is entrained by fuel flow at the inlet of the filler pipe. In this study, a refueling experiment using water was conducted and multiphase flow inside the filler pipe was visualized using LIF. Two flow patterns were observed: spray flow and liquid film flow. A model was developed to describe the relationship between entrained air flow rate and tank pressure. The model estimates the entrained air flow rate considering the contributions of droplet pressure drag and liquid film frictional resistance.

PN Emission from Heavy Duty Vehicles Complying with Cold Start Emissions Regulation

Kazu Oshima･Hiroyuki Yamada (Tokyo Denki University)･Hidenori Konno (Toke Engineering)･Atsushi Sato･Jun Okabe･Haruya Jyo (Environment & Information)

SPN23, SPN10 and regulated gas emissions have been evaluated from Heavy Duty vehicles complying with the Japanese regulation in 2016 that include emission measurement with cold start mode. Several vehicles were tested on the Chassis Dynamometer. with World Harmonized Vehicle Cycle so called “WHVC” mode. Observed common properties were increased emissions of NOx during warming up process, and increased SPN10 emissions in high load conditions.

Brake Emission Reduction Approaches under the impact of EU7

Christof Danner (AVL List GmbH Graz)･Kinzo Takahashi･Toru Nishizawa (AVL Japan K.K.)

The Euro 7 regulations emphasize non-exhaust emissions, particularly brake emissions, under the Global Technical Regulation (GTR) 24 framework. With a stringent limit of 7 mg/km/vehicle for passenger cars and light commercial vehicles, current systems often fail to comply without regenerative braking. Challenges include measurement inaccuracies, evolving standards, and integrating reduction factors for electrification. Early solutions like brake disc coating and brake dust filters are in development, alongside plans for In-Service Conformity (ISC) and Real-Driving Emissions (RDE) testing. Manufacturers face pressure to innovate brake systems, balancing performance, comfort and emissions reduction through new materials, technologies, and testing methods.

Development of Non-Exhaust Brake Wear Emissions Measurement System for New European Regulations

Kenji Kondo (HORIBA Europe GmbH)

While the exhaust gas emissions have been reduced significantly from vehicles by the tighter regulations, the emitted proportion of non-exhaust brake wear particle emissions have been focused recently. Therefore, emissions regulation on brake wear particle emissions will be introduced in Euro 7. In this paper, the measurement technology of a brake wear particle measurement system will be reported.

A simulative investigation for transient engine development involving methanol and ammonia fuel blends

Bhawandeep Sharma･Madan Kumar (Guangdong Technion Israel Institute of Technology)

Transient operated vehicles have significantly contributed to higher GHG emissions due to combustion complexity. Considering this challenge, renewable fuels such as methanol and ammonia are studied in transient conditions. The work includes comprehensive experimental and numerical analysis of methanol-ammonia blends for genset engine. The analysis focuses on the performance, combustion and emissions by tuning load, injection timing, spark timing, and blend ratio. Results indicate that increasing ammonia in the fuels increases indicated efficiency. Moreover, more ammonia percentage in the fuels leads to decrement in NOx and CO2. However, BSFC and combustion duration increased due to slow combustion properties of ammonia.

Development of elemental technologies using ethanol-containing fuel

Tomohiro Nakayama･Kenu Takahashi･Takahiro Seino･Yuuki Itou･Masami Shiki･Ryo Iwashita･Shohei Matsuoka (SUBARU)

This paper describes the results of actual verification of fuel characteristics such as power output and exhaust gas emissions, as well as reliability using ethanol-containing fuel (E30 or higher), as well as issues and countermeasures.

Multi-Cylinder Demonstration of a Pre-Chamber Lean-Burn Gasoline Combustion System Using Real-Time Fuel Reforming

MAKOTO KANEKO (Chiba University)･TOSHIO YAMADA (Sustainable Engine Research Center Co., Ltd.)･TATSUYA KUBOYAMA･YASUO MORIYOSHI (Chiba University)

In the two preceding reports, we demonstrated low NOx emissions and highly efficient combustion in a single-cylinder engine using a high-pressure storage tank containing the same composition as the experimentally verified reformed gas and mechanical supercharging.
In this study, we conducted a feasibility study on a four-cylinder system using real-time fuel reforming with high controllability achieved through improved warm-up heating using halogen lamps. Through a 1D simulation study, we confirmed that this can be achieved even with a small single-stage turbocharger.

Research on Small Two-stroke Opposed Piston Power Unit

Akira Iijima･Yoshiaki Yamazaki･Jinru Liu･Shumpei Fukushima･Yusuke Otaki･Ikumi Okawara･Sou Watanabe (Nihon University)

Internal combustion engines for electric powertrains are required to have high power density, high thermal efficiency, and low vibration and noise characteristics. As an engine that can achieve such characteristics, we focused on the two-stroke opposed piston engine. In this study, a small two-stroke opposed piston engine have prototyped and investigated its basic combustion characteristics.

Optimization of Injectors for Improving Thermal Efficiency and Reducing Smoke in the Combustion of Liquid Synthetic Fuels and OME

Zijian Jiang･Shusuke Tanaka･Hiroya Yamamoto･Gen Shibata･Hideyuki Ogawa (Hokkaido University)

The lower heating value of OME is lower than that of GTL, which increases the injection quantity under the same load and reduces thermal efficiency. In this study, injectors for OME and GTL were selected to supply the same amount of heat within the same injection duration, with nozzle diameter and the number of nozzles as parameters. Using a constant-volume combustion chamber, the smoke generated in the spray interference area was quantified, and thermal efficiency and emission performance were evaluated through engine testing.

Influence of the oil formulation on the oil consumption mechanisms and the emission behavior of hydrogen combustion engines

Marcus Gohl･Robert Wulff･Mathias Braun (APL Automobil-Prueftechnik Landau GmbH)･Pierre Chapelot･Peter Scholl (TotalEnergies Lubrifiants SA)･Michael Guenthner･Thorsten Fuchs･Philipp Emanuel Jung (Rheinland-Pfaelzische Technische Universitaet)

Decarbonizing transport is a key goal for governments and industry, driving innovation in powertrain technologies. Hydrogen combustion engines have emerged as a promising solution for applications ranging from heavy-duty vehicles to two-wheelers. However, hydrogens unique properties pose challenges for engine lubrication, requiring tailored formulations to address pre-ignition, particulate emissions, water contamination, and wear protection. This study explores the impact of base oil types and additives on oil consumption mechanisms and particulate emissions. Results from medium-duty truck engine tests highlight key strategies to optimize lubricants and support hydrogen engine development.

The experimental study on the effect of diesel fuel composition and distillation properties on PM production

Kohei Katori･Tsutomu Hasegawa･Masahiro Seo･Ko Takahashi (Idemitsu Kosan)

In recent years, there has been a growing demand to produce the diesel fuel with the aim of expanding the use of cracked diesel fuels. Since the cracked diesel fuels have a high aromatic content which increases the amount of PM produced, it is necessary to take countermeasures such as lightening. Hence the amount of PM produced was determined by bench tests, using fuels varying aromatic hydrocarbon species and distillation characteristics, to identify the impacts on PM production quantitatively.

Alcohol Diffusive Combustion Technique as an Alternative Diesel Combustion (First Report)
-Survey of ignition assisting method and minimum condition of pilot flame-

Takayuki Fuyuto･Kenji Fukui･Yoshiyuki Mandokoro･Reiko Ueda･Kazuaki Nishikawa･Teruaki Kondo･Yoshifumi Wakisaka (Toyota Central R&D Labs.)

Alcohol fuels, methanol and ethanol, can be promising alternative fuel for diffusive combustion in heavy-duty diesel engines. In this study, we surveyed various ignition method of methanol fuel in literatures, and found that the diesel pilot ignition is the most robust ignition technique, although which cannot be recognized to be carbon neutral combustion. The minimum condition of pilot flame area and location formed by diesel pilot injection was evaluated by in-cylinder visualization. A new injection and ignition strategy for pilot spark-ignition main diffusive combustion which uses methanol as mono-fuel was proposed. This strategy is demonstrated in the next report.

Alcohol Diffusive Combustion Technique as an Alternative Diesel Combustion (Second Report)
-Methanol-monofuel pilot spark-ignition and main diffusive combustion-

Kenji Fukui･Yoshiyuki Mandokoro･Reiko Ueda･Kazuaki Nishikawa･Teruaki Kondo･Yoshifumi Wakisaka･Takayuki Fuyuto (Toyota Central R&D Labs.)

In order to develop a methanol-monofuel diffusive combustion technology, a new combustion concept composed of spark-ignited pilot spray and the main spray diffusive combustion, which was proposed in the first report was demonstrated using an optical engine. After spark-ignition of pilot spray, the pilot flame is formed and propagates in the swirl direction while it forms flame holding behind the electrode. Then, main sprays are cascadely ignited in the swirl direction. By adding pilot spray after spark ignition the pilot flame can be extended toward the nozzle, which can ignite all main sprays during injection period.

Gasoline Component Specific Study Affecting Intake Valve Deposits

Shouta Tobe (SUBARU)･Henry Du (Lubrizol Management)

The effect of intake valve deposits (IVD) has been studied during multi-port injection (MPI), but the effect of fuel blowback on the intake system has also been confirmed in direct injection (DI). The impact on IVD may be an issue when gasoline produced by different methods, such as carbon-neutral fuel (CNF), is used. Since confirming the adverse effects requires an enormous amount of man-hours, a method that simulates the engine environment to confirm these effects is attracting attention .
In this study, we utilized a "simulated deposit test device for intake valves in L2 type gasoline engines(L2-simulator) " set according to the Chinese GB standard(GB 19592-2004). to identify gasoline components that affect IVD. The results of this investigation are hereby presented.

Effect of Engine Oil Containing Ultrafine bubbles on Reduction of Friction Loss in Piston-Cylinder System
-Influence of cylinder bore honing specifications and lubricant viscosity-

Kai Horiba (Graduate School of Tokyo City University)･Yuji Mihara (Research Center for High Hydrogen Engine Tribology HEET Tokyo City University)･Syusuke Hoshino･Takumi Iwata (Graduate School of Tokyo City University)･Masakuni Oikawa (Research Center for High Hydrogen Engine Tribology HEET Tokyo City University)

The effect of nanoscale ultrafine bubbles (UFB) generated in engine lubricating oil by the ultra-fine hole method on reducing friction between the piston and cylinder was investigated. Friction force measurements using a floating liner engine showed that UFB reduces FMEP due to the bubble density. In this study, the relationship between the friction reduction effect was verified by changing the cylinder honing specifications and oil viscosity.

Reduction of Engine Bearing Friction with Engine Oils Containing Ultrafine Bubbles
-Effect of generation density and oil viscosity-

Shusuke Hoshino･Kai Horiba･Takumi Iwata (Graduate school of Tokyo City University)･Masakuni Oikawa･Yuji Mihara (Research Center for High Efficiency Hydrogen Engine and Engine Tribology (HEET), Tokyo City University)

The effect of ultrafine bubbles generated in engine oil on the friction characteristics between the crank journal and plain bearing was verified using an engine bearing testing rig. In this study, the effect on friction reduction was investigated by changing the ultra-fine bubble density and oil viscosity in engine oil.

Influence of Piston Design Parameters on Oil Film Volume at Piston-Cylinder Interface

Yasuhiro Ishikawa･Ruka Matayoshi･Akemi Ito (Tokyo City University)･Kenichi Yamashita (Isuzu Advanced Engineering Center)

Understanding the lubrication oil supply mechanism to a piston-cylinder interface is crucial for predicting its lubrication performance through numerical analysis. This study aims to investigate the influence of piston design parameters on oil supply. Using a visualized single-cylinder engine, the oil film volume, which strongly correlates with the supplied oil quantity, was measured. The relationship between skirt geometry and oil film volume was clarified.

A Study on Water Evaporation Characteristics from Emulsified Oil in a Hydrogen Engine

Akemi Ito･Itsuki Motomiya･Daisuke Hiyama･Ryosuke Ichimura (Tokyo City University)

Hydrogen engines produce more water than conventional fossil fuel engines. It was shown in our previous report that oil emulsification occurred during vehicle operation in winter and the correlation between the water content in oil and the period when oil temperature exceeds the dew point. This paper will discuss the results of unit tests conducted to investigate the time and temperature required for water to evaporate from emulsified oil.

Study of Fuel-Efficient Engine Oil for Automobiles Using Re-Refined Base Oil (RRBO)

Yuta Watanobe･Takumaru Sagawa･Kiyoshi Hanyuda･Ayano Otsuka (Shell Lubricants Japan)

As a countermeasure against climate change, the automotive industry is required to reduce CO2 emissions; thus, introduction of low-viscosity, fuel-efficient engine oil is being promoted. Meanwhile, the use of re-refined base oils (RRBO) obtained by recycling the used lubricants are being adopted around the world. The performance of fuel-efficient engine oils for automobiles using RRBO would be reported in this presentation.

Development of the flat low viscosity engine oil JASO GLV-2 0W-16

Shunsuke Nara･Junichi Sudo･Kazuo Yamamori･Yuta Uematsu･Satoshi Hirano･Noriya Ishizaki･Atsuhisa Tamano (Toyota Motor)･Shogo Eryu･Yushi Kato (ENEOS Corporation)

Achieving carbon neutrality necessitates significant reductions in CO2 emissions and enhancements in fuel efficiency.
To address this challenge, we have developed a fuel-efficient flat viscosity oil by utilizing advanced low-viscosity base oils and viscosity index improvers.
Our formulation enhances fuel efficiency across low to medium temperature ranges while maintaining reliability at high temperatures.
Furthermore, this oil meets the new engine oil quality standard, JASO GLV-2, and is expected to effectively reduce CO2 emissions in both new and existing vehicles.

Relationship Between Degradation of Additives in EV Fluid and Friction Properties

Toshimitsu Numata･Sawa Araki･Yuriko Fujii･Kiyotaka Nakamura (Nissan ARC)

In this study, EV fluid was oxidatively degraded.
The degradation of the additives was analyzed by LC-MS, IR, and GC-MS.
In addition, friction properties were evaluated using a ball-on-disk type friction tester, and sliding surfaces were analyzed by TOF-SIMS and AES.

Support Technology for Digital Validation and Visualization of Carbon Neutrality
-Simulation Setup in Digital Validation Protocol-

Toshiji Kato (Doshisha University)･Kimitoshi Tsuji (Digital Twins)･Tsunehiro Saito (AGC)･Masahiro Okamura (JSOL)

The simulation methods and conditions used in digital validation protocols must be clearly defined because they affect the results. Therefore, we will explain the simulation conditions that must be met based on the numerical calculation principles.

Initiatives for Virtual Testing Using Digital Twins and Digital Authentication II
-Comprehensive CO2 Reduction and New Manufacturing System-

Kimitoshi tsuji (Digital Twins)･Tosiji kato (Doshisha University)･Tsunehiro Saito (AGC)･Masahiro Okamura (JSOL, INC.)

In manufacturing, certification through actual testing has limitations due to the lack of reproducibility and the diversity of conditions. Therefore, this paper introduces an initiative aimed at certification through virtual testing, using a full-vehicle model of an EV as a tool for digital certification, which can be applied to off-cycle credits that will be implemented in 2030 and can also be used for vehicle performance development.

Study and Proposal on model traceability using cryptographic hash function

Masahiro Okamura (JSOL)･Kimitoshi Tsuji (Digital Twins)･Tsunehiro Saito (AGC)･Hideto Noyama (Mitsubishi Heavy Industries Thermal Systems)･Toshiji Kato (Doshisha University)

This paper reports on the case study of verification using cryptographic hash functions for the traceability of models and results, which is important for digital certification using simulation models for off-cycle credits (OCC) for CO2.

Study and Proposal on OCC for Automotive Glass using EV Model (Second Report)
-POC of Digital Authentication Protocol with EV Cabin Thermal Model-

Tsunehiro Saito (AGC)･Hideto Noyama (Mitsubishi Heavy Industries Thermal Systems)･Masahiro Okamura (JSOL)･Kimitoshi Tsuji (Digital Twins)･Toshiji Kato (Doshisha University)

OCC (Off-Cycle Credit) is the important credit regulation for CO2. In the first report, we reported the results of the study on OCC using the EV cabin thermal model. In the second report, we report the simulation of annual CO2 emissions of EV as a proof of concept of a digital certification protocol using the EV cabin thermal model.

Prediction of Mutual Influence of Design Changes in Inverters and Motors in Electrified Vehicles　for CN(Carbon Neutral)

Ken Iwatsuki (AISIN)･Shiho Arimoto (Hitachi Astemo)･Kimitoshi Tsuji (Digital Twins)

With the worsening of climate change, CO2 has become a significant global challenge. We updated the previously developed model to examine the visualization and reduction of CO2 associated with product development. It introduces the interdependencies arising from changes in the design of inverters and motors in electric vehicles. Due to its high confidentiality, this model confirmed the potential for extensive CO2 reduction through collaboration with other companies in the cloud.

Construction of Online Co-Simulation Environment (Sixth Report)
-Development of Machine Learning-Based Surrogate Model of 1D Thermal Plant Model-

Ogata Kenichiro･Keijiro Koide･Motoki Takahata･Kohei Tanaka･Kazuaki Watanabe (Honda Motor)

In product development, a highly efficient vehicle development process is required from performance design to performance verification. MBD (Model-Based Development) is cited as a crucial technology for executing the highly efficient vehicle process. However, a detail granularity model as the development progress leads to higher computational costs. This study focused on a 1D thermal plant model as the detail granularity model and explores the use of machine learning as one of a method to enable fast computation while fulfilling model applications in the performance verification phase. A surrogate model was constructed using GBRT (Gradient Boosting Regression Tree) algorithm. The surrogate model achieved real-time speed while maintaining high prediction accuracy and generalization performance.

Accuracy verification of circuit analysis method using coupled Electrical and mechanical 1D models in collaboration with Tier 1 and Tier 2 suppliers

Masashi Inaba (DENSO)･Hiroki Nakamizo (Institute of Science Tokyo)･Masanari Ueda (SIEMENS)･Takao Egami (AC Technologies)･Yoshiko Ikeda (Toshiba Electronic Devices & Storage)･Daisaku Mukaiyama (Rubycon)･Yoshinori Aruga (KOA)･Wataru Hijikata･Hideaki Fujita (Institute of Science Tokyo)･Takuya Shinoda (DENSO)

In recent years, the coupled Electrical and mechanical 1D model has been attracting attention due to the need to shorten the ECU development period. Last year, we analyzed the operation of actuator drive circuits and calculated ECU heat generation by simulation using a model shared among companies. This year, based on the results, we actually created a board to check the agreement between the experimental results and the simulation.

Acuracy verification of robust design for location of thermal interfacial material by using MBD

Kazunari Hashimoto (DENSO)･Ryuta Yasui (Institute of Science Tokyo)･Masashi Inaba (DENSO)･Takao Egami (AC Technologies)･Yoshiko Ikeda (Toshiba Electronic Devices & Storage)･Yoshinori Aruga (KOA)･Daisaku Mukaiyama (RUBYCON)･Masanari Ueda (Siemens)･Kazuyoshi Fushinobu (Institute of Science Tokyo)･Takuya Shinoda (DENSO)

In recent years, technological innovation has been accelerating, and it is expected that the development period will be shortened by fully utilizing CAE.
Last year, we proposed that htatthe method the circuit analysis of circuit elements and actuators as 1D models was combined with heat transfer analysis and optimization algorithm analysis. In this year we verified the agreement between the analytical and experimental results.

The evaluation of the actuator behavior in a low-temperature range - The effect of the low temperature characteristics of the Aluminum Electrolytic Capacitors -

Daisaku Mukaiyama (Rubycon)･Masashi Inaba (DENSO)･Masanari Ueda (Siemens)･Yoshinori Aruga (KOA)･Yoshiko Ikeda (Toshiba Device & Storage)･Takao Egami (AC Technologies)･Kazunari Hashimoto (DENSO)･Hideki Jounokuchi (Nagoya Institute of Technology)･Masayoshi Yamamoto (Nagoya University)･Takuya Shinoda (DENSO)

Based on the system simulations, we showed the effect of the aluminum electrolytic capacitors' low-temperature behavior on the actuator's control in the previous works. We assembled an actuator system that followed the previous system simulation to confirm whether the same phenomena appear in a low-temperature condition. We will show the details of these results.

Resistor and board modeling for Tier 1 and Tier 2 collaboration using MBD

Yoshinori Aruga (KOA)･Masashi Inaba (DENSO)･Masanari Ueda (Siemens)･Daisaku Mukaiyama (Rubycon)･Hiroki Nakamizo (Institute of science)･Haruki Takei (Siemens)･Takao Egami (AC technologies)･Yoshiko Ikeda (Toshiba Electronic Devices and Storage)･Hideki Jounokuchi (Nagoya Institute of Technology)･Takuya Shinoda (DENSO)

In the thermal design of in-vehicle electrical equipment that is becoming smaller and more sophisticated, it is important to consider not only semiconductors but also the small components (resistors, capacitors, etc.) in their peripheral circuits. In this report, a 1D model (coupled mechanical, electrical circuit, and thermal model) of an actuator drive circuit shared by WG members consisting of Tier1 and Tier2 is discussed. In addition, modeling of the resistors and boards used will be discussed.

Impact of Semiconductor Model Accuracy and Its Application to Actuator Drive Circuit Operation for MBD Collaboration Between Tier 1 and Tier 2

Yoshiko Ikeada (Toshiba Electronic Devices and Strage Corporation)･Takao Egami (AC Technology Corporation)･Masashi Inaba･Takuya Shinoda･Kazunari Hashimoto (DENSO)･Masao Ueda (Siemens Corporation)･Daisaku Mukaiyama (Rubycon Corporation)･Yoshinori Aruga (Koa)･Hideki Jonokuchi (Nagoya Institute of Technology)

In automotive electronic equipment, the accuracy of semiconductor models is crucial for MBD (Model-Based Development) and front-loading. Using the high-precision Spice model of MOSFETs and the high-precision model of gate driver ICs reported previously, we evaluate the impact of model accuracy and its application to actuator drive circuit operation.

Redefining Engineering Ethics in the Context of Society and Technology

Norihisa Miki (Keio University, Department of Mechanical Engineering)

As the impact of technology on society grows exponentially, engineering ethics must be redefined within the context of its relationship with society. This redefinition should not merely follow the transformations of society but rather anticipate them, actively designing a desirable future. In this lecture, I will discuss engineering ethics and society, drawing on specific examples and, to a significant extent, my personal perspectives.

Characterizing micro-ethics in autonomous vehicles using scenarios

Masao Ito (NIL)

To ensure the safety of autonomous vehicles, we must consider the relationships with the numerous agents that operate autonomously, including autonomous vehicles. We use the concept of microethics as one way to clarify these relationships. However, it is generally difficult to demonstrate its characteristics, and in this paper, we attempt to explain this using test scenarios shown in ISO 34502 and other standards.

Assessment of risky driving levels from traffic accident statistics data analysis on high-velocity runaway accidents on public roads
-Estimating the aggressiveness of high- velocity vehicles in causing human injuries through traffic accident statistics data analysis-

Yasufumi Sekine (Fukuyama University)

In collision accidents, the velocity at which the accident occurs is an important factor that determines the severity of human injuries, such as the fatal or serious injuries rate of vehicle occupants or pedestrians. In this study, the author attempted to derive an approximate equation for the relationship between vehicle velocity and the fatal or serious injury rate by traffic accident statistics data analysis, and to clarify the dangers of accidents that occur at velocity significantly exceeding the velocity limit.

Derivation of Support Concepts Based on the Driver's Cognitive Abilities

Nanae Michida･Masanori Honda･Kuninori Suzuki･Yoh Yamazaki･Kenta Okada･Hiromune Obayashi (Mazda)

Over 900 participants took part in measurements using two tasks displayed on a screen (a spatial recognition task using right-turn scenes of automobiles and the Stroop task). Based on the performance in each task, participants were classified into four groups. For each group, causal analysis was conducted on the results of a questionnaire regarding difficult driving scenes and the reasons for these difficulties. This was done to examine support concepts tailored to different ability types.

Research on direct carbon dioxide capture technology from motorcycle exhaust gas

Momona Hirao･TORU UENISHI (Kitami Institute of Technology)

The feasibility of capturing carbon dioxide directly from motorcycle exhaust gas was examined in this study. A device was built to capture carbon dioxide from the tailpipe of a motorcycle that uses a two-cylinder gasoline engine, and we evaluated its performance. By comparing the capture performance with that of a fixed-bed flow device that simulates the exhaust gas composition of a motorcycle, we were able to clarify the system development guidelines.

Research on carbon recycling technology in vehicles.

Toru Uenishi･Momona Hirao (Kitami Institute of Technology)

The feasibility of a system that captures carbon dioxide from motorcycles and converts it into fuel was examined in this study. A model was developed to capture carbon dioxide from a motorcycle's tailpipe and convert it into fuel, and we identified it using a fixed-bed flow reactor. Using the constructed model, we evaluated the performance and clarified the guidelines for system development.

CO₂ separation and capture from combustion engine exhaust gas using physical adsorption method
-Impact of engine types on CO₂ adsorption and desorption characteristics-

Tadanori Yanai (Shizuoka Institute of Science and Technology)

A CO₂ separation and capture system using a physical adsorption method with zeolite for internal combustion engines has been developed. In this study, impact of the difference between the two engine types (gasoline engine and diesel engine) on the CO₂ adsorption and desorption characteristics were investigated.

Development of an exhaust gas aftertreatment system using plasma and HC adsorption

Ryoichi Shimamura･Ryutaro Tamaki･Chihiro Matsuda･Takamasa Imanishi･Kazuhiko Madokoro･Kazuya Naito･Tatsuya Ehara (DAIHATSU MOTOR)･Ryoichi Ogawa･Tetsuya Shinozaki･Minoru Ito (CATALER)

We have developed an after-treatment system for removing particle number (PN) and hydrocarbon (HC) using non-thermal plasma and HC adsorption .
Electrification of vehicle leads to lower exhaust gas temperature and constraint　on onboard space.
To overcome those matter, we have developed a compact and low temperature dependence system, and investigated the PN and HC removal performance under cold start condition.

Enhancement of reaction by molecular diffusion in Three-way Catalyst Porous Particles Membrane Filter

Mariko Watanabe (Sophia University)･Katsunori Hanamura (Japan Science and Technology Agency)

An effect of porous structure on enhancement of reaction was investigated by numerical simulation for a single agglomerated Three-way catalyst porous particle and its stacked porous particles as a thin membrane layer, including Knudsen diffusion in the element structure of a single porous particle.

Development of DPF Model Compatible with Whole Vehicle Model and Study on Regeneration Control (Second Report)

Kenta Hasegawa (Tokyo Denki University)･Norifumi Mizushima (AIST)･Taichi Kimura･Hiroyuki Yamada (Tokyo Denki University)

A diesel particulate filter (DPF) model that can be incorporated into a vehicle model developed with OpenModelica has been updated. In former model, exhaust gas temperature was estimated from table data, resulting serious discrepancy with experiments with transient condition such as a worldwide-harmonized light vehicles test cycle (WLTC).In this report, A simplified turbocharger and diesel oxidation catalyst (DOC) thermal model were developed and implemented to the vehicle model to more accurately predict the exhaust gas temperature behavior at the DPF inlet. By using the developed model, the effects of various DPF regeneration methods on post injected fuel consumption were investigated.

Modeling of gasoline particulate filters with combined use of membrane and catalyst coatings

Grigorios Koltsakis (Aristrotle University Thessaloniki)･Elias Mylonidis･Dimitrios Karamitros (Emisia SA)

The combination of a non-active membrane with a catalytically active coating could maximize the filtration efficiency potential of gasoline particulate filters. The paper addresses the challenges for optimum design and application of such a concept. A physics-based model is initially calibrated vs engine bench experimental data from both membrane and catalytically coated filters. The internal morphology of each filter is obtained by optical techniques and used as input to the model. The validated model is then applied to virtually benchmark alternative designs considering PM/PN filtration efficiency, soot oxidation, ash impact and emissions during filter regeneration.

Development of optimized GPF performances based on GPF Model

Sungmu Choi･Jiho Cho･Hyungjun Kim･Sangmin Lee (Hyundai Motor)

Models of GPF were developed and used to find optimal GPF. At first, coated GPF and membrane GPF were considered. Coated GPF has lower PN filteration efficiency and higher soot regenerability. To increase PN filteration efficiency, removing crack and reducing mean pore size of washcoat on GPF are proposed based on simulation results. PN filteration efficiency of coated GPF was improved to meet with higher soot regenerability. In case of membrane GPF, it has higher PN filteration efficiency and lower soot regenerability. To enhance its soot regenerability, additional coating on membrane GPF was considered, it is called hybrid GPF. The amount of coating on membrane GPF must be optimized in view of soot regenerability and pressure drop. Based on hybrid GPF model, 25g/L~50g/L coating amount was proposed to get effective soot regenerability with allowable pressure drop increase.

2-D Numerical Modeling on the Urea SCR Catalyst Installed in a Diesel Engine

Fuka Yoshida･Jin Kusaka (Waseda University)

Urea selective catalytic reduction (SCR) system is a promising technique to reduce NOx emission from Diesel engines by injecting urea water in front of the catalyst. For numerical modeling on the Cu-CHA catalyst, 31 surface reactions including 5 active sites coupled with the reaction of urea thermal- and hydro-decompositions have been constructed. Moreover, to estimate boundary conditions for simulations, the temperature distributions are measured in the radius direction in front of the SCR catalyst. The results of the numerical simulation constructed have reasonable agreement with the engine test results with consideration of reaction paths and surface chemical species.

An Optimal Development of dual SCR system for Heavy duty Diesel Engine using Genetic Algorithm

Jiho Cho･Sung Moo Choi･Hyung Jun Kim･Sang Min Lee･Dong Min Hwang (Hyundai Motor)

In this study, a predictive model-based SCR control optimization technique using a genetic algorithm is suggested and developed to minimize the development effort of DCU (Dosing Control Unit) mapping especially for cc_SCR system. This technique is an optimization method that automatically finds the cc_SCR control mapping that satisfies the target NOx emission and NH3 slip level in a short time using a genetic algorithm for an integrated prediction model consisting of a DCU model and a catalytic reaction model. By using this technique, it is possible to reduce calibration effort of the cc_SCR system and ensure the robustness of emission controls.

Simulation and Performance Prediction of Spray Droplet Behavior in a Urea-SCR System Using PIV-DDM

Shotaro Nara･Nachi Takeuchi･Joe Ono･YukiYuki Kawamoto･Naoya Fukushima･Masayuki Ochiai･Tetsuo Nohara (Tokai University)

Understanding the flow behavior inside the urea-SCR system is important for predicting exhaust gas purification performance. This study attempts to reproduce the internal flow behavior without performing flow field calculations via CFD (Computational Fluid Dynamics), using a method combining PIV (Particle Image Velocimetry) and DDM (Discrete Droplet Model). A comparison with experiments simulating the inside of the exhaust pipe confirmed the same tendency. This report presents the findings.

Development of an Efficient Testing Methods for In-Vehicle Battery Durability Evaluation Utilizing Bidirectional Power Supply System

Toshimichi TAKAHASHI (MEIDENSHA)･hiroki KAZAMI (KIKUSUI ELECTRONICS)

Discussions are being held at the United Nations regarding in-vehicle battery durability evaluation for light duty vehicles and heavy duty vehicles. For in-vehicle battery durability evaluation in the vehicle development and markets, it is desired that efficient testing methods be realized without modifying the vehicles. As one of the testing methods, a bidirectional power supply system capable of charging and discharging continuously was utilized to carried out an evaluation with a light duty vehicle.

Investigation of Impedance Measurement Methods for EV Traction batteries mounted on EVs

Takumi Mori･Nozomu Teranishi (HIOKI E.E. CORPORATION)･Toshimichi Takahashi (Meidensha)

It is important to establish and standardize a method to measure and evaluate the electrical characteristics of EV traction batteries mounted on EVs as an inspection methodology for EV performance and safety. In this study, multiple methods for measuring the internal resistance/impedance of battery packs mounted on EVs were evaluated. The experiment results and comparative investigation is reported, to propose an appripriate and versatile method.

Relationship between Mass Burnt Fraction 50% Crank Angle and Low-Frequency Components in Cylinder Pressure When Ignition Timing was delayed

Keiichi Nagashima (Honda R&D)･Kazuo Tsuchiya (Meiji University)

When the ignition timing was delayed for the purpose of engine protection or early activation of the exhaust catalyst, cylinder pressure with two peaks might occur.　 The cylinder pressure with two peaks also confirmed a correlation between mass burnt　fraction 50% crank angle and amplitude of the low-order sin frequency component (bk).　 In addition, bk might become negative.　It is caused by the high cylinder pressure in the calculation section where the part of the bk calculation equation is negative.

Bulk Quench of Turbulent Premixed Combustion Under Dilution and Lean Operating Conditions in DI Gasoline Engine

Masaaki Kato･Yoshirou Shiina･Takeshi Tsuda (SUBARU)

The bulk quenching behavior of flame propagation near the lean and dilution combustion limits, including cold conditions, are measured in an optical access DI gasoline engine. Combustion behavior near the flamability limit is analyzed using flame image analysis, combined with unburned gas emissions by means of a high-speed HC measurement taken directly behind the exhaust valve.The effects of In-cylinder gas flow control and in-cylinder state quantity were clarified.

Euro 7 OBM and solutions to on-board emissions assessment

Scott Savage･Ian Short (None)

Light-duty Euro7 on-board monitoring (OBM) is mandated from November 2026. Processing of raw emissions and trip data will be performed off-board by the EU to determine in-use emissions performance for vehicle types, guiding targeted ISC and Market Surveillance testing. On-board evaluation of NOx and PM emissions are required at an individual vehicle level. Manufacturers will need to develop strategies to detect when a vehicle may be incapable of passing an ISC test. This paper provides a concise summary of OBM requirements for Euro7 and presents Ricardo's approach to OBM, including solutions to allow on-board emissions compliance evaluation.

Analysis of Real Driving Emissions Measurements During Adverse Weather Conditions Using a Laser Spectroscopy Based Portable Emissions Measurement System

Jorge Eduardo Lamas･Kenji Hara･Yoshinori Otsuki (HORIBA)

Real driving emissions measurements are attracting attention to understand emission behavior when vehicles are subject to various environmental conditions which are difficult to replicate in laboratories. The effect of adverse weather conditions on real driving emissions is still not well documented for emission components of recent interest, such as ammonia. A newly developed Portable Emissions Measurement System using laser infrared spectroscopy is utilized to measure and compare emissions of NH3, N2O and NOx, among other components, during on-road tests of a gasoline vehicle in different weather conditions. Vehicle parameters are monitored and their apparent effects on emissions are discussed.

Integrated Development of Chassis and Powertrain Systems: Enhancing Vehicle Motion Control through Predictive Dynamics and Virtual Validation

Felix Matthies･Marcus Perner･Wei Han･Mark Wielitzka (IAV)

In modern automotive engineering, developing complex cross-domain functions is crucial for vehicle motion control. Functions managing lateral, longitudinal, and vertical dynamics of subsystems like chassis and powertrain are central. A holistic approach to drive system development is essential to address complexity and enhance safety, comfort, efficiency, and agility. This paper presents IAVs latest concepts, emphasizing virtual methods and functional safety. We highlight using a virtual environment with qualified simulation models for preliminary hazard analysis, risk assessment, and function validation, ensuring high-quality development while reducing costs and time.

Initial damage sensing by the vibration modes of AE waves in vibration fatigue

Toshiharu Kaneshiro･Takashi Maeda･Satoshi Ikeda･Yoshimi Sato (Estech)

Vibration fatigue is a phenomenon where materials are damaged by repeated stress and vibration, and it is important in aircraft and automobiles. AE (Acoustic Emission) measurement is a non-destructive evaluation technique that can detect initial cracks, but it has problem of being affected by external disturbances in vibration fatigue. In this paper, we propose a measurement method that focuses on the vibration modes of AE wave to distinguish between testing vibrations and fatigue fracture vibrations.

Evaluation of the application of a flattened dynamometer that can be installed in the wheel well of a vehicle on the bench testing.

Yuichi Takasaki･Kenji Terada･kentaro Kondo･Kohei Yasumoto･Kouichi Eitoku･Yoshihisa Hojo･Daisuke Kozakai (Toyo Denki Seizo)

We have achieved a high capacity, flattened dynamometer that can be installed in the wheel well of a vehicle. This dynamometer is designed to accommodate the vehicle's mechanical brake and has an output per wheel of 160 kW, 800-2500 min-1 and a maximum short-time torque of 3800 Nm.
This paper reports on the evaluation of the application to bench tests, including mechanical braking tests.

Numerical analysis of cabin particulate matter to improve cabin air quality

Mie Hirahara･Yusuke Nakamura･Masato Hijikuro･Akane Masui･Keigo Shimizu･Kazuki Ito･Yuki Koda (Mazda)

This study reports the results of numerical analysis of particulate matter, especially PM2.5, in vehicle interiors for the purpose of improving air quality in vehicle interiors. Specifically, the airflow in the cabin of an actual vehicle was calculated when the air conditioning mode was changed, and the behavior of particulate matter following the flow was analyzed numerically. The results of the numerical analysis are compared with experimental results and their validity is discussed.

Investigation of convective heat transfer to various parts of the human body for air conditioning efficiency and thermal comfort

Akane Masui･Yusuke Nakamura･Masato Hijikuro･Mie Hirahara･Koki Kawakami･Kazuki Ito･Akira Togii･Keigo Shimizu (Mazda)

In this study, we investigated the effects of parameters such as external environmental conditions and air conditioning settings on convective heat transfer in various parts of the human body by experiments and numerical analysis for air conditioning efficiency and thermal comfort. As a result, we gained knowledge that is useful for improving the interior environment.

Thermal manikin for optimizing the cabin climatization control strategy

Patrick Schutzeich (FEV Vehicle GmbH)･David Hemkemeyer (FEV Europe)･Kai Franke･Daniel Linse (RWTH Aachen University - Chair of Thermodynamics of Mobile Energy Conversion Systems (tme))･Simon Schilling (FEV Europe)･Noriyuki Muramatsu (FEV Japan)

Cabin conditioning is an important factor in the development of thermal management system for electrified vehicles. The control strategies to be developed for this purpose are becoming more sophisticated and consider factors such as air quality and passenger comfort. Objective calibration of the cabin conditioning software is therefore often very complex. FEV has developed a thermal comfort manikin which is used to automate the calibration process. The presentation will focus on the design of the thermal manikin and the generation of benchmark data. In addition, FEV's tool chain for the automated calibration of the cabin conditioning software will be presented.

1D Model Development of Thermal Management System in BEV

Takeru Kakita (DENSO)･Matthew Blom (DENSO Automotive Systems Australia)･Yousuke Yasuda･Yusuke Sato･Tomohiro Sudo (DENSO)

Since it is difficult for BEV to store a large amount of energy, it is important to make air conditioning compatible with running distance by thermal management by appropriately moving a heat pump. In this paper, we report the development of the MBD method for the thermal management system including the heat pump, which is difficult to predict due to the phase change of the refrigerant.

Tread Depth Monitoring for Automotive Tires

Matthias Kreschmann (Continental Automotive Technologies GmbH)･Nicolas Guinart･Remi Gobin (Continental SCR)

The Tread Depth Monitoring system determines tire tread depth during vehicle operation by measuring wheel rotational speed, vehicle speed, and dynamic radius, considering tire temperature, pressure, and load. It uses sensors for rotational speed and vehicle speed, with dynamic radius calculations based on tire parameters. The system issues warnings for low tread depth, potentially triggering automatic service alerts and communicating with driver assistance systems. It uses traditional tires sensors for temperature and pressure, ensuring accurate tread depth determination and optimized vehicle operation.

Towards a multi-performance real time capable tire model

Christian Ludwig･Benjamin Rieff (Cosin scientific software AG)

FTire was first used in durability simulation, but was soon used to simulate other performances "Ride, NVH, Wear, Handling including thermal dependent friction and structural stiffness". The evaluation of tire performance on a driving simulator requires a highly accurate real time capable multi-performance tire model to give test drivers the same possibilities as on track. This paper introduces a new methodology to generate the complex steering wheel undulation obtained when driving across a real road surface. We will present further first results of the next step where tire-suspension interaction occurring at limit handling will be addressed.

A Tire Model Extension To Express Water Depth and Velocity Influences on Tire Performance

Toshiyuki Hyuga (Siemens)･Carlo Lugaro (Siemens Industry Software and Servises B.V.)

The need for virtualization is increasing in tire and vehicle development. The performance on wet road such as braking and handling performance are one of the most important evaluation items .
In this context, as an additional function of MF-Tyre/MF-Swift, the Magic Formula has been extended based on the physical phenomena occurring between the tire and the wet road surface to capture tire slip characteristics with different speeds and water film thicknesses.

Development of a Method for Predicting Tire Cornering Force Curve Using Machine Learning

YUDAI MIKAMI･HARUYUKI SUZUKI (Sumitomo Rubber Industries)

We developed a method for predicting the cornering force curve of tires using machine learning. Feature selection and the direction of changes for each feature are determined using a linear model, and a GBDT-based model is used for training. During this process, the direction of changes is incorporated into the model as monotonic constraints. This approach allows us to develop a machine learning model that balances prediction accuracy and interpretability.

Improvement of Transient Yaw Response Using Electric Power Steering Considering Tire Characteristics

Daiki Morimoto･Yasunori Seki･Daisuke Yokoi (Suzuki Motor)

Yaw rate response to steering varies with vehicle and tire characteristics, an optimal response speed exists, as confirmed by subjective evaluations. Using a vehicle-steering model that incorporates tire characteristics from actual data, a simulation was conducted to adjust the rise time of the yaw rate's transient response to this optimal value using Electric Power Steering (EPS). This adjustment was found to enhance evaluations in real vehicle tests.

A Study on the Fail-Safe Technology of the Tire Built-in Sensor Using the Tire Deformation Model

HEEYOUNG JO (Illinois Institute of Technology)･SUNJE KIM (Chungnam National University)･KYUWON CHOI (Illinois Institute of Technology)

Recently, tire built-in sensors (i-Tire sensors) have been commercialized and used as tire management systems for logistics trucks.
It is a project to reduce costs by managing tire life using an i-Tire sensor that can detect tire conditions such as pressure, temperature, and deformation.
However, since the i-Tire sensor is mounted inside the tire, it is not easy to directly check the condition of the sensor.
Therefore, in this paper, we studied the technology to detect the failure of the i-Tire sensor using a tire deformation model.

Development of Tire and Vehicle Performance Prediction Model using Machine Learning

Yeonsang Yoo･Yongdae Kim･JinSil Kyeong (Hyundai Motor)

As tires are the only parts that contact with road surface, they deliver all the forces from the road and have enoumous effect on most of the vehicle performance. Therefore, it is essential to set and secure tire performance targets in the early stage of vehicle development. The purpose of this study is to develop a method for setting tire performance targets to meet the vehicle performance target in the early development stage. Huge amount of tire test data and vehicle simulation data were analyzed and machine learning technology was used to develop this method.

Vibration Analysis of Tire Using 3D Digital Image Correlation

Yuki Kato (Kochi University of Technology)･Soma Watahiki (Kozo Keikaku Engineering)･Masayoshi Otaka (Ono Sokki)･Mitsuki Togoshi (Kozo Keikaku Engineering)･Yoshiho Oda (Ono Sokki)

While driving, tires are subject to excitation forces from the road surface and engine, and exhibit complex vibration behavior. However, because they are high-speed rotating bodies, it is difficult to measure their vibration using contact sensors with cables. In this study, we evaluated the vibration characteristics of tires using digital image correlation, which enables non-contact, multi-point vibration measurement.

Study on construction of system for estimating friction characteristics between tire and road on the forward road surface
-Sensor selection and algorithm construction for forward road friction characteristics estimation system-

Atsushi Watanabe･Ichiro Kageyama･Yukiyo Kuriyagawa･Tetsunori Haraguchi (Nihon University)･Tetsuya Kaneko (Osaka Sangyo University)･Minoru Nishio (Absolute Co., Ltd.)

In the previous report, we reported on road surface categorization utilizing multiple environmental information related to road surface friction characteristics on snowy and icy roads. In this study, we investigated the selection of effective sensors and the construction of an estimation algorithm for estimating the friction characteristics of the forward road surface. As a result, the effectiveness of the proposed method is verified and the feasibility of a forward road surface friction estimation system is discussed.

New efforts to construct road friction measurement system

Ichiro Kageyama (Consortium on Advanced Road-Friction Database)･Atsushi Watanabe･Yukiyo Kuriyagawa･Tetsunori Haraguchi (Nihon University)･Tetsuya Kaneko (Oosaka Sangyo University)･Minoru Nishio (Absolute)

We verified the results of the continuous friction characteristic measurement system shown so far, extracted the problems, and identified the points to be corrected for the continuous friction characteristic measurement. Next, we will show the construction of a new measurement system aimed at improving accuracy and its measurement results.

Measurement of Road Contact Load During Straight Driving of a Car Using Tire Wheel Deformation

Hiroshi Tachiya･Masahiro Higuchi･Akira Shibuya (Kanazawa University)･Daisuke Yokoi･Naoki Sekino (Suzuki Motor)･Kenta Konishi･Daiki Morimoto (SuzSuzuki Motor Corporation)

A method for measuring the triaxial load acting on the tire contact surface during straight-line driving is studied using strains at several locations on the wheel. The appropriate strain measurement locations, measurement their directions, and rotation angles for measurement were determined. Furthermore, actual measurement experiments were conducted on a test bus to confirm the validity of the method by comparing it with a commercial force sensor at some conditions.

Prospects of Sustainable Automotive Society
-Directions of Technical responses, and Challenges-

Yoshio Maeda (Research organization for Next Gen, Vehicle of Waseda Univ.)

The world's average temperature in 2024 were the highest on record, and disasters caused by abnormal weather occurred all over the world. Reducing GHG emissions has become an urgent issue for the sustainability of the planet. With carbon footprints now being required for automobiles through LCA, the automobile industry will need to work together beyond its traditional framework. This presentation will outline the challenges and provide a direction for how to address these issues.

End-of-Life Automotive Battery Value Chain: Opportunities for Critical Materials Supply Chain Resilience

Hadi Moztarzadeh (Advanced Propulsion Centre UK)

With the growing adoption of electric vehicles (EVs) comes a new demand for the critical minerals needed to build batteries, alongside a potential second-use market. The European Battery Directive provides targets for collection and recycling of EV batteries with minimum targets for recycled content in new EV batteries.
Developed by the Advanced Propulsion Centre UK (APC), in conjunction with experts from industry and academia, the automotive battery end-of-life value chain map shows the path of the growing re-use and recycling industry. This new value chain details the journey of an automotive battery from the end of vehicle use to second life and recycling, to become cathode active material (CAM) and anode active material (AAM).

Material-recyce technology of automobile shrederdust

shogo izawa･yuta urushiuama･akinori yoshimura (Nagoya University)

National Composites Center (NCC) of Nagoya University is conducting research and development efforts with the aim of creating a resource recycling society for automobile materials. 　We believe that efforts to recycle Automobile Shredder Residue (ASR), which is currently used as thermal recycling, are also an important technological element. In this lecture, we will introduce examples of our research efforts.

Revolutionizing Battery Management: AI-Powered Digital Twin for Predictive Maintenance and Enhanced Performance

Nikolaus Keuth･Gerhard Schagerl (AVL List)

This presentation introduces an AI-powered Digital Twin technology designed to enhance battery safety and reduce warranty costs. Leveraging data from development, telematics, and in-vehicle usage, it offers accurate state-of-health monitoring, anomaly detection, and range optimization. Key benefits include a 97% identification rate of battery issues a month before occurrence, a 92% reduction in recall volume, and thrice more accurate range predictions. The AI-powered Digital Twin uses machine learning for continuous BMS improvement and a scalable analytics backend, enhancing battery performance and safety significantly.

Development of Slip Rate Estimation Method Based on Torque Control of Four-Wheel In-Wheel Motor

Toshiyuki Ajima･Wataru Hatsuse･Masaru Yamasaki (Hitachi)

In order to control the four-wheel in-wheel motors and improve vehicle characteristics, a slip rate estimation method using motor torque has been developed. In this presentation, we report a basic study of slip rate estimation method based on motor torque control of each wheel during driving, and the effectiveness of the method is verified on a test vehicle.

High fidelity IPMSM model used for sensor-less algorithm comparative study

Marek Lazor･Petr Kuchar･Xiang Wang (Ricardo PLC)

Mathematical models of Interior Permanent Magnet Synchronous Motors (IPMSM) are well known in industry, however they are normally low fidelity or computationally intensive. Recent interest has focused on higher fidelity models, known as Digital Twins. These models complement the development of advanced control techniques, such as sensor-less algorithms, where sensitivity of position estimation accuracy to minor parameters like cross-coupling terms can be understood. These algorithms enable reduced cost and increased robustness in automotive applications. This paper presents a high-fidelity digital twin model, a comparative study of published sensor-less algorithms, and an innovative sensor-less algorithm allowing low-speed operation without high-frequency injection.

Development of Next-Generation e: HEV Control System for Synchronization with Driver's Emotion

Ryosuke Narimoto･Sadaharu Maeda･Yohei Ukai･Masatoshi Saito･Shinobu Kurachi･Naoya Murata･Hiroki Gunji･Kazuki Shiki･Akari Nagakura (Honda)

Due to global trends towards environmental protection, the electrification of automobiles is accelerating. However, pursuing emotional value in electric vehicles is also important in automobile development. In this study, a new control system has been developed for the e: HEV system that synchronizes with the driver's emotions to enhance the emotional value of electric vehicles, and confirmed performance that sets a new benchmark for electric vehicles.

Changes in dQ/dV depending on battery abnormalities

Hyunjun Jo･Hyunjun Jang･Sijoong Kim･Taekyu Kang (Hyundai Motor)

As the adoption of electric vehicle(EV) expands, the need for diagnostic technology for the safety of battery is gaining attention. A variety of abnormal conditions may occur in battery, each leading to distinct impacts. The Abnormalities are dependent on each other and affect each other, which makes difficult to understand the exact occurrence mechanism of the event. This research suggests the relationship with the change in dQ/dV depending on diverse battery abnormalities. It shows that dQ/dV changes occur under abnormal conditions, enabling the diagnosis of abnormal cells and also the classificaiton of the abnormalities. We expect the abnormal cells can be identified through monitoring the changes in dQ/dV.

Future E-Truck Innovation: Next generation e-Powertrain concept for maximum flexibility and cost scaling.

Christoph Danzer･Hubertus Christian Ulmer･Rico Resch･Volker Ambrosius (IAV)

The Contribution Starts with an Outlook to Optimum Voltage Levels for the HV-System of Future Heavy-Duty CVs. This and Further Requirements of Future Drive Systems Define the Boundary Conditions for the New Flexible CV-Electric-Drive-Concept. The Basic System Can be Flexibly Integrated into the Vehicle in Longitudinal and Transversal Direction with a High Degree of Common Parts. The transversally installable system employs an adapted design of the basic system and enables an installation as an high efficienct and compact axle-drive. The system may be optimized in terms of installation space and continuous performance by using Phase Change Cooling.

Study of optimal thermal - power management control for Hybrid Electric Vehicle based on vehicle system 1D simulation model

Yuya Hato･Wei-Hsiang Yang･Toshio Hirota･Yushi Kamiya (Waseda University)･Kiyotaka Sato (Mazda)

When using the lithium-ion battery in the electric vehicle, it is necessary to take measures against thermal runaway and degradation at high temperatures and battery voltage drop at low temperatures. In order to achieve this objective, it is important to control the temperature and power of the battery in an appropriate and efficient manner. We studied how to manage lithium-ion batterie and thermal system in hybrid electric vehicles using a vehicle system 1D simulation model and optimization method.

A Study on Calculation Method of EV Range Per Charge for Heavy-Duty EV
-Considerations of Test Duration and Influence of Regenerative Braking Characteristics-

Shinji Yoshikawa･Nobunori Okui (NALTEC)

The regulation in TRIAS stipulates to test the EV range per charge of heavy-duty EVs at constant speed using actual vehicles. The EV range per charge is, however, influenced by the characteristics of regenerative braking during deceleration. Therefore, we studied on a calculation method of EV range per charge from the electric energy stored in the battery and the rate of electric energy consumption, considering the test duration and the influence of the characteristics of regenerative braking.

A Study on 4WD Chassis Dynamometer Evaluation Method for xEV Performance Evaluation. (Second Report)
-Analysis of the Impact of 4WD Chassis Dynamometer Performance Requirements Evaluation Parameters on Electric Power Consumption-

Noriaki Nakate (JATA)･Hisakazu Suzuki (NALTEC)･Isamu Inoue (Ono Sokki)･Tomonobu Furuta (Meidensha)･Yasuhiro Ogawa (HORIBA)

In order to reproduce the actual driving conditions of an xEV on a 4WD chassis dynamometer, it is essential to appropriately reflect the unique power performance of an electric vehicle (especially the transient characteristics including sudden acceleration and deceleration) on the platform.
Following the results of the first report, this second report discusses evaluation indices that consider the impact on power consumption rates of the 4WD chassis dynamometer necessary for evaluating actual driving characteristics of xEV

Driving Efficiency and Innovation in BEVs
-Next-Generation Electronics-

Ayman Ayad･Philip Brockerhoff (Schaeffler AG)･Takuya Mimori (Schaeffler Japan Co., Ltd)

Electrification is transforming the automotive landscape, driven by the need for efficiency, cost reduction, and sustainability. This presentation introduces advancements in power electronics and charging technologies for BEVs, focusing on wide-bandgap (WBG) materials like silicon carbide (SiC). Key topics include innovative inverter technologies such as the Smart 3-Level topology and hybrid Si-SiC modules, which optimize performance and reduce costs. Additionally, strategies for integrating 400 V charging with 800 V systems are explored, emphasizing efficiency and scalability. These innovations highlight how advanced high-voltage architectures can redefine BEV efficiency, affordability, and sustainability, paving the way for the future of e-mobility.

Research on Thermal Insulation for EV Batteries with Latent Heat Storage System

Tatsuyuki Ohashi･Haruyuki Iijima (F.C.C.)･Takahiro Nomura･Tomokazu Nakamura (Hokkaido University)

Towards achieving carbon neutrality by 2050, the widespread use of EVs requires battery insulation technology suitable for cold climates. We are researching an EV battery insulation system with latent heat storage and high insulation technology. This presentation reports on the latent heat storage technology for EV battery insulation.

Development of Battery Data Generation Technology
Using Time Series Wasserstein GAN based on Deep Learning.

HYUNJUN JANG･TAEKYU KANG･WOOSUNG KIM (Hyundai Motor)

This paper presents a GAN-based deep learning approach for generating synthetic battery data. While lithium-ion batteries in xEVs are widely studied using deep learning to analyze their electrochemical characteristics under various conditions (current load, SOC, temperature), obtaining real data is challenging. Battery degradation testing is time-consuming, and extreme condition testing (like internal short circuits) is dangerous. The proposed solution uses a GAN architecture where Generator and Discriminator networks compete to create new, realistic battery data that matches the patterns of existing data, enabling testless data generation for battery research.

Realizing an energy and resource saving society by Dynamic Wireless Power Transfer for EVs

Naoya Kato･Tetsuji Mitsuda･Keisuke Tani･Takuya Osugi･Koji Yamaguchi･Yuki Konno･Mitsuhiro Ishihara･Toshiki Nagamatsu･Atsuki Ito･Keiichi Oshima (DENSO)

In order to achieve carbon neutrality, it is important to reduce the carbon generated during the production and the disposal of electric vehicles. The authors examined the specifications of Dynamic Wireless Power Transfer system while vehicle running, which has the potential to significantly reduce the on-board battery capacity, and estimated the effects of energy and resource savings.

Early fault detection in lithium-ion batteries using machine learning

Maximilian Kloock･Ethelbert Ezemobi･Seyedmehdi Hosseininasab･Lennart Bauer (FEV Europe)

Major battery faults include soft and hard short circuits, abnormal aging, over-charging, and over-discharging. Early detection of these faults can help to mitigate against thermal runaway. This work demonstrates a machine learning algorithm designed to detect these faults in an early stage and, consequently, prevent severe damage through thermal runaway. The machine learning algorithm combines the advantages of data-driven and model-based approaches. The algorithm is validated under dynamic load conditions using standard driving profiles of 100 simulated battery packs - each pack consisting of 80 cells, each including one faulty cell.

Activities of the Vehicle Exterior Noise Division Committee of the Society of Automotive Engineers of Japan

Toru Yamazaki (Kanagawa University)

The Exterior Vehicle Noise Division Committee was established in FY2021 to address various issues related to vehicle noise. Its goals include developing methods to predict and evaluate noise as a source of disturbance, assessing its environmental impact, and understanding its effects on nearby residents’ awareness and reactions. This presentation highlights the committee's progress since its inception.

Subjective evaluation of a single motor vehicle noise with low frequency components

kazuma Yabuuchi (Kanagawa University Graduate School)･Shigenori Yokoshima (Kanagawa Environmental Research Center/Kanagawa University)･Makoto Morinaga (Daido University)･Koichi Makino･Tetsuya Doi･Sakae Yokoyama･Tomohiro Kobayashi (Kobayasi Institute of Physical Research)･Toru Yamazaki (Kanagawa University)

The authors conducted a subjective evaluation experiment in a low-frequency sound chamber. Single pass-by noises emitted by heavy vehicles with a predominant sound pressure level in the low-frequency range of 40 Hz or 50 Hz were used as stimuli. In this paper, we discussed the influence of the sound pressure level of the predominant frequency in the low-frequency component on the oppressive or vibratory feeling, which is characterized as the effect of low-frequency sound, and on the discomfort feeling due to the noise.

Objective evaluation of awaking due to road traffic noise
-Basic study using wearable devices-

Makoto Morinaga (Daido University)･Shigenori Yokoshima (Kanagawa Environmental Research Center / Kanagawa University)･Yoshiki Umezaki (Creative Research and Planning)･Toru Yamazaki (Kanagawa University)

Traditional studies on the effects of traffic noise on sleep have often used subjective surveys, but there's a demand for more objective scientific approaches. This research explores a simple and objective method to assess sleep disturbances by using wearable devices to detect awakenings and analyze their correlation with noise levels.

Study on Traffic Noise Data Generation Using Generative AI
-Possibility of generating traffic noise by manipulating parameters in latent space-

ManYong Jeong (National Institute of Technology, Numazu College)･Ritsuki Matsunaga (Advanced Course, National Institute of Technology, Numazu College)

This study examines the feasibility of applying generative AI technologies—such as Generative Adversarial Networks (GANs) and diffusion models—to flexibly and accurately generate traffic noise data that are difficult to record or obtain in real-world environments. The demand for large-scale, diverse datasets to support the development of traffic noise prediction models and the evaluation of noise abatement measures has been growing. However, direct collection of such data is often hampered by high measurement costs, environmental constraints, and privacy or security concerns.
In this research, we use existing measured data as training input to synthesize various traffic noise waveforms using generative AI. More specifically, we construct a conditional generative model that integrates meta-information—including traffic volume, vehicle mix, running speed, and weather conditions—to produce realistic noise waveforms. We then evaluate whether these generated signals can faithfully replicate key acoustic properties such as spectral and temporal characteristics. Furthermore, we verify the utility of the proposed method by applying the generated data to the training of noise prediction models and the evaluation of anomaly detection algorithms.
Ultimately, this study aims to demonstrate that improving the quality of simulated data via generative AI technologies can enhance the foundational capabilities for traffic noise analysis and inform the development of related policies.

Outline of road traffic noise prediction model “ASJ RTN-Model 2023”

Yasuaki Okada (Meijo University)･Katsuya Yamauchi (Kyushu University)･Shinichi Sakamoto (The University of Tokyo)

The Acoustical Society of Japan (ASJ) has had the Research Committee on Road Traffic Noise to develop a prediction model for road traffic noise for more than 50 years. As a result of the research activities, a new version of model, “ASJ RTN-Model 2023”, was published in last April. It is an upgrade version of the previous model, “ASJ RTN-Model 2018”, proposed in 2019. In developing the latest version, existing knowledge was widely taken into account, in particular, the sound power levels of road vehicles under non-steady running conditions and calculation methods for sound propagation were improved in wide range.

Application of the Momentum Algorithm for Active Noise Control
-Fast Convergence for the HVAC Compressor Noise in an Autonomous Bus-

Seongyeol Kim･Junseok Choi･Doyeon Kim･Sang-Kwon Lee (Inha University, Department of Mechanical Engineering)

This paper presents an ANC algorithm to reduce vibroacoustic noise from the HVAC compressor in an autonomous bus. The compressor generates high-frequency noise due to shell vubrations, with dominant frequencies in the 100-600Hz range, impacting passenger comfort. While the FXLMS algorithm is commonly used, it struggles with nose outside peak frequencies. To improve performance, a momentum algorithm was applied, offering faster convergence and lower residual error. The results demonstrate significant noise reduction both at peak frequencies and across a wider frequency range, enhancing passenger comfort.

eNVH Analysis of a PM Motor with Uneven Magnetization and Rotor Eccentricity

Rabah Hadjit (ESI)･Sumeet Singh (EM Works)･Mario Felice (virsolTech Engineering Consulting, LLC)

This paper investigates the electromagnetic performance, and NVH characteristics of a forty eight-slot and eight-pole interior permanent magnet motor designed for automotive applications. Utilizing advanced virtual modelling and simulation techniques, the study conducts a comparative evaluation of rotor configurations with even and uneven magnetization under varying eccentricities - static, dynamic, and mixed. The resultant radial and tangential electromagnetic forces are then compared for their contributions to surface velocities and noise radiation.
This methodology provides a comprehensive understanding of how magnetization and allows minimizing noise and vibration while maximizing performance in automotive applications.

Impact of Vibration Applied to the Vehicle by the Hub Nut Clamp Type Vehicle Restraint Device (Second Report)

Toshimichi TAKAHASHI･Toshinari KOZEKI (Meidensha)･Masao FURUSAWA (F-MA Consulting)

The previous report showed that the eccentric hub nut flange excited the upper center pithing mode which was not appeared on the actual driving on the road. This report explains the theoretical back ground of this pithing mode, then the counter measure was done by installing the damper unit to the place of antinode of the pithing mode even in a case of difficult concentricity of the hub nut flange.

Analysis of Obstacle Avoidance Performance of a Personal Mobility Vehicle (PMV) Equipped with an Active Inward-Tilting Mechanism under Braking Conditions

Tetsunori Haraguchi (Nagoya University / Nihon University)･Tetsuya Kaneko (Osaka Sangyo University)

The authors have investigated the obstacle avoidance capability of a PMV equipped with an active inward-tilting mechanism through both a theoretical analysis of its mechanism and validation using a dynamic simulation model. In this study, they focus on the obstacle avoidance characteristics under braking conditions, which closely resemble real-world avoidance maneuvers. The results demonstrate the superior avoidance capability of the PMV, including the effective tread width expansion effect during braking achieved by its front two-wheel configuration.

Simulation-Based Analysis of Obstacle Avoidance in Personal Mobility Vehicle (PMV) with an Inward Tilting under Braking Conditions

Tetsuya kaneko (Osaka Sangyo University)･Tetsunori Haraguchi (Nagoya University)･Ichiro Kageyama (Nihon University)

The authors have previously studied the obstacle avoidance performance of a PMV with an active inward-tilting mechanism, examining its mechanical principles and validating findings through dynamic simulations. This paper investigates braking-induced avoidance maneuvers resembling real-world scenarios, using a multi-degree-of-freedom dynamic model to analyze variations in vehicle state and tire forces, thereby demonstrating the PMV's avoidance capability.

Analysis of the influence of motorcycle dynamics on frame flexibility

Tsuyoshi Katayama (Kurume Institute Technology)･Reiya Haraoka (Kurume Institute of Technology)･Masanori Myoyo (Kurume Institute Technology)･Takahiko Yoshino (Kurume Institute of Technology)

When the bending freedom of the front frame of a motorcycle becomes soft, the weave mode becomes unstable. However, it has not yet been clarified what factors determine the softness of the frame rigidity. In this paper, the effect of mechanical elements on the flexibility of the frame is clarified by applying an analytical method obtained by the energy flow method to the equation of motion for the bending degree of freedom of the front frame. An index of flexibility is proposed, based on the results.

Analysis of the Influence of Motorcycle Dynamics on Frame Flexibility (Second Report)
-Examples of Applications of Flexibility Indicators-

Takahiko Yoshino･Reiya Haraoka･Masanori Myoyo･Tsuyoshi Katayama (KURUME INSTITUTE OF TECHNOLOGY)

When the bending freedom of the front frame of a motorcycle becomes soft, the weave mode becomes unstable. This paper examines the factors that contribute to the softness of a vehicle's frame using an index that evaluates the magnitude of bending displacement of the front frame.

Examination of the Appropriate Alignment of Omnidirectional Cameras in the Position Measurement System for a Motorcycle Using Image Processing

Junji Hirasawa (Ibaraki KOSEN(College of Tech.))

In this paper, a reexamination for the position measurement system is described, focusing on the number of cameras, the orientation of the optical axes, and the relative positions of the cameras. The position accuracy of the proposed method is assessed through verification experiments. Driving experiments are conducted to measure the locus for a motorcycle.

Analysis of the synchronization of the rider's posture, gaze, and maneuvers with the vehicle's motion.

Masakazu Tomosada･Masaru Katayama･Yoshihiro Fujioka･Yukito Fukushima･Daiki Izumi･Takeshi Kobuki･Syusuke Yamane･Akiyasu Takami (National Institute of Technology, Matsue College)

We have developed a system that can synchronously measure and analyze the rider's posture, gaze, and operation while riding and the vehicle's motion.
The results of riding analysis using this system will be reported.

A Proposal for Translating Vehicle Motion Sensing Data into Symbolic Sequences with Temporal Dynamics
-Hear the Motorcycle Sing-

Tomoya Kitani･Takuro Sone･Yotaro Yada (Shizuoka University)

This paper proposes a method for representing time-series motion sensing data as symbolic sequences that consider time scales .
It enables the computational analysis of actual physical sensing data from vehicle motion using machine learning and natural language processing techniques such as LLMs .
The results of this analysis can contribute to objectively assessing the experience of riders and the vehicle dynamics.

Development of Sub System Sled-Based Lateral Pole Impact Test

Gustavo Maturana･Alba Marquez･Jordi Vinas･Genis Mensa･Carles Vidal･Victor Garcia (Applus+ Idiada)

During the vehicle development, the full-scale testing is one of the most timing and resources consuming part of the process. A solution has been proposed where full-scale Lateral Pole tests can be simplified to subsystem sled tests, requiring less resources in terms of BiW while allowing to reproduce impact tests conditions, where vehicle deceleration and intrusion are applied in a controlled way to reproduce crash kinematics. This paper explores the development of this sub-system setup, which can be applied afterwards for restraint system development. It presents CAE activities, component characterisation tests, sub-system validation and methodology definition involved in the process.

A Comprehensive Approach to Hydrogen Vehicle Crash Testing Challenges

Victor Garcia Santamaria･Miguel Angel Gallego Ruiz･Genis Mensa Vendrell･Carles Vidal Aguado (Applus+ IDIADA)

Crash testing of hydrogen-powered vehicles presents unique challenges compared to its other clean alternatives such as electric vehicles. Main challenges in security and quality involve preventing and containing leaks, managing hydrogen's high flammability and flame invisibility. Crash safety regulations also present its own challenges, since it is required to be able to test at nominal tank pressure with hydrogen to fulfill them. This paper goes through all the challenges mentioned and how an experienced crash test laboratory faces them by developing new methodologies, procedures, protocols, and tools, and using possible alternative gases to prepare and test those vehicles.

Raising the bar for heavy quadricycles safety in urban mobility
-Structure and occupant protection assessment of a L7-e vehicle through Euro NCAP tailored crash test protocols-

Carles Vidal Aguado･Jordi Salvat Pamies･Emilia Romero Tienda･Genis Mensa Vendrell･Victor Garcia Santamaria (Applus+ IDIADA)

Euro NCAP 2014-2016 testing campaign results for heavy quadricycles revealed safety concerns. The EU-funded REFLECTIVE project aimed to enhance the safety perspective for this category vehicles by developing a safe, compact, zero-emission L7-electric vehicle for urban use and last-mile deliveries. This paper evaluates the vehicle's passive safety through various crash tests: subsystem test, frontal crash, frontal sled, and lateral crash. By implementing adequate restraint systems, validating deformation and occupant interaction through simulations, and employing appropriate design, the REFLECTIVE vehicle was successful in raising safety standards for heavy quadricycles after applying the Euro NCAP testing protocols for this type of vehicles.

Evaluation of ATD and Human Body Model Responses in Rear Impact Scenarios

Simona Roka･Pablo Lozano (IDIADA Spain)･XuFeng Li (IDIADA China)･Sergio Crespo (IDIADA Spain)

This study compares the BioRID II anthropomorphic test device and THUMS version 6.1 human body model in Euro NCAP Whiplash assessment conditions, addressing the critical issue of rear-impact collisions which represent 27.8% of passenger vehicle crashes. Using an open-source environment with VIRTUAL project components, the research analyzed head, T1, and pelvis excursions, along with moments, forces, and accelerations at key anatomical landmarks. Results revealed significant differences between ATD and HBM responses, while seat adjustments improved BioRID II's T1 acceleration. Biofidelity assessment showed favorable correlation at the cervical vertebrae level, validating both tools for whiplash injury evaluation.

A Study of Lower Extremity Injuries of Seat Position in Frontal Collisions.

TOSHIMITSU NEGISHI･YUUTA KASUYA･SHOGO NAGANO･SHIGEKI HAYASHI･HIROAKI IMAI･YUUJI NAKANE (Toyota Motor)

The introduction of diverse evaluation conditions (crash speed, dummy type, seating position) is under discussion by various new car assessment programs. This study aims to investigate lower extremity injuries of passenger occupant at fully rearward seat position in frontal collisions. The increase of lower extremity movement caused the ankle to lock and the increase of moment at the ankle joint. The range of ankle joint motion for plantarflexion in the dummy differs from human body. The result indicated that the necessity of more research for lower extremity injuries in various seat position and biofidelity.

Investigation of the Effects of Muscle Activation in Pedestrian Crashes Using THUMS

Takuma Miyazaki･Yojiro Iizuka･Yoshiki Takahira･Hiroshi Miyazaki･Shigeki Hayashi･Hiroaki Imai･Yuji Nakane (Toyota Motor)

The number of pedestrian fatalities accounts for 36% of traffic accident deaths in Japan, indicating a high proportion. To reduce pedestrian injuries and fatalities,understanding the mechanisms of injuries is still important theme. This study investigates the effect of pre-crash pedestrian postures on behavior during crashes using the human body FE model THUMS. Previous research proposed a model modification to match the rotational range of the trunk of THUMS with that of humans during muscle activation. Different behaviors were observed depending on the presence of muscle activation.

Development of 50th Percentile Female Human Body Model

Noriyuki Fujita･Takao Matuda･Yuuiti Kitagawa (Toyota Motor)

There is a growing research need for gender equity of occupant protection in vehicle collisions. Small female dummies are used in vehicle crash tests, while midsize female dummies are not available. In this study, a 50th percentile female human body model was developed. The model was used to simulate impact kinematics of a female occupant in a vehicle frontal collision and to investigate the gender difference in injury risk.

Development of Pregnant Occupant Models and Prediction of Placental Abruption in Vehicle Collisions Using these Models

Tomohiro Izumiyama･Atsuno Tsuji (Mazda)･Yumiko Tateoka (Shiga Medical Science)･Ryusuke Asahi (Mazda)･Masahito Hitosugi (Shiga Medical Science)

The mechanism of placental abruption in pregnant occupants during a collision remains unclear. In order to predict this injury, the 30-week pregnant occupant models were developed and a method for evaluating the severity of this injury on these models was established. Additionally, the effect collision velocities, seatbelt positions and placental positions on the severity of this injury was analyzed. This paper reports the mechanism of placental abruption inferred based on these results.

The novel restraint system for the safety of wheelchair user vehicle passengers

Masahito Hitosugi･Ayumu Kuwahara (Shiga University of Medical Science)

Recently, increased number of wheelchair user vehicle passengers have been involved in frontal motor vehicle collisions. Some fatal injuries were caused by inappropriate seatbelt restrictions. A lap and shoulder belt does not adequately fit most wheel chair user passengers because of the way the wheelchair constructed. We have confirmed the submarine phenomenon and high values of chest deflection for the wheelchair passengers by sled tests representing a 48 km/h frontal collision. Therefore, we propose a novel restraint system for wheelchair users traveling in vehicles. The effects or the novel system examined by sled tests is shown.

Factors influencing thoracic and abdominal injuries in far-side collisions and injury reduction

Hitoshi Ida･Yoshito Kusuhara･Michihisa Asaoka･Masashi Aoki (TOYODA GOSEI CO., LTD.)･Masahito Hitosugi (Shiga University of Medical Science)

We analyzed injury trends and influencing factors in far-side collision accidents. Since it was found that reducing injuries to the thorax and abdominal area is important for occupants restrained by seat belts, we performed simulations using the human body model THUMS to examine methods for reducing thorax and abdominal injuries.

Analyses of injury mechanism with human FE models in accidents involving an electric kick scooter

Daisuke Ito･Shun Fujishima (Kansai University)

In this study, a human finite element model was used to analyze the mechanism of injury occurrence during a electric kick scooter accident. The human body behavior and the degree of injury to each part of the body during collision with a four-wheeled vehicle and with a curb block were evaluated, and it was shown that the collision angle had a significant effect on the behavior.

International and domestic trends of safety regulations on motor vehicles

Masafumi Matsusaka (MLIT)

Introduce the trends of international discussions and MLIT's efforts regarding automotive safety regulations towards reduction of deaths and injuries from road traffic accidents.

A Study on the Actual Situation and Trends of Pedal Operation Error Accidents based on Event Data Recorders and other data in Micro Investigations

Hideki Matsumura (NALTEC)･Motoki Sugiyama･Yakekazu Iwata (Institute for Traffic Accident Research and Data Analysis)

In recent years, pedal operation error accidents have become a social problem, but the specific situations of these accidents have not been fully understood. On the other hand, event data recorders (EDRs) have been installed in many recent vehicles, and it has become possible to understand the driver's operating conditions during the accident. we studied the actual conditions and trends of these accidents based on EDRs and other data obtained in micro investigations of the actual accident.

Advancing Automated Driving Systems development and safety evaluation with the Automated Mobility Partnership

Jacobo Antona-Makoshi･Gibran Ali･Kaye Sullivan･Vicki Williams (Virginia Tech Transportation Institute)･Alex Hatchett (Global Center for Automotive Performance Simulation)･Kevin Kefauver (Virginia Tech Transportation Institute)

The Automated Mobility Partnership (AMP) is a platform supporting the development and safety evaluation of automated driving systems. The AMP portal integrates events from over 35 million miles of naturalistic driving data and a decade of U.S. police-reported crash data curated by the Virginia Tech Transportation Institute. AMP provides remote access for advanced data analysis, visualization, scenario generation, and human driver benchmarking. This paper demonstrates AMP's utility in supporting the identification of hazardous behaviors, the development of driver monitoring strategies, the application of integrated scenario-based analyses, the definition of crash risk-based criteria, and conformance with safety standards.

Construction of Traffic Accident Risk Assessment Method for Road Alignment Using Digital Road Map

Ryoma Ohtani･Katsuma Ando･Ryoya Hara･Hiroshi Kuniyuki (Suwa University of Science)

Based on road alignment information from digital road maps, an assessment method for the risk of traffic accidents caused by road alignment, which are often found in hilly and mountainous areas, was constructed. The number of accidents per curve section was investigated and verified against accident risk index evaluated by the length of the straight section before the curve and the curve curvature. The results showed that the accident rate on curves can be evaluated using this accident risk index.

Analysis of Causes for Single Motorcycle Accidents in Hilly and Mountainous Areas Using Motorcycle Driving Simulator

Yuta Katayama･Taisei Kitagawa･Yusuke Numao･Hiroshi Kuniyuki (Suwa University of Science)

In this study, an evaluation course was set up using a motorcycle driving simulator, assuming an S-shaped curve on a hilly and mountainous road, and a comparison of driving maneuvers between a model rider and a novice rider was conducted. As a result, novice riders are more likely to deviate from the lane than model riders due to inadequate motorcycle leaning operation, and it was indicated that this difference in driving ability is one of the factors contributing to accidents.

Study of Robust Design to Ensure the Manufacturing Quality of High-Density Mounted Electronic Components on the printed board.

Hisao Nishimori･Jun Muto･Tomoyuki Furukawa･Miiyu Orinaka･Yasufumi Shibata (Toyota Motor)

With the increasing demands for higher functionality in electronic components, it is essential to develop design techniques that ensure stable solder joints during the manufacturing process when implementing advanced semiconductors and components on printed circuit boards at high densities. Since lift-off of the solder joints was observed on experimental boards, this paper introduces considerations and discussions on key design parameters for robust design utilizing simulations and AI.

Predicting Engine Physical Sensor Values Using Multiple Regression Models

Yuki Yano･Kenichi Morizane･Koshiro Wada･Nobuo Yunoki･Kenta Kobayashi (Mazda)

Replacing onboard sensors with AI models offers numerous advantages, including weight and cost reduction, as well as greater flexibility in layout design. In particular, multiple linear regression models are lightweight, easy to interpret, and well-suited for implementation.
This study introduces the development process of a multiple linear regression model for accurately predicting diesel engine exhaust temperature and exhaust pressure, along with the results of validation using an actual vehicle.

Study on Improving the Robustness of Stroke Sensors for Steer-by-Wire EPS

Yohei Shirakawa･Yoshiaki Yanagisawa･Yukio Ikeda (PROTERIAL)

We are investigating an inductive stroke sensor for detecting the displacement of the rack shaft in a steer-by-wire EPS. We examined the mechanism of detection accuracy deterioration caused by the inclination of the rack shaft relative to the sensor. To mitigate this accuracy deterioration, we devised two novel sensor structures with high robustness. The effectiveness of these structures was validated through electromagnetic field simulations.

Actual vehicle electromagnetic noise evaluation and prediction technology for electrical components

Yukihiro Serizawa (Sohwa & Sophia Technologies)

As electrification progresses, EMI issues must be overcome to ensure efficient development. This technology can predict electromagnetic noise before measuring actual equipment, and by utilizing CAE, it realizes test stress and contributes to MBD. Here, we will introduce case studies and suggest ways to proceed in the future.

Development of an artificial weather chamber that reproduces a dynamic weather environment for autonomous driving sensors　(3rd report)

Satoshi Akaike･Hiroyuki Enoki･Yuri Saito･Hisayasu Shima (ESPEC)

With the advancement of autonomous driving technology, the onboard sensors may be affected by various weather conditions, which necessitates the development of new evaluation methods.
In this report, we continue from the previous study to evaluate sensor visibility under fog and rain conditions, aiming to address the upcoming mandatory installation of automatic braking systems and the enhanced performance evaluation under adverse weather conditions.

How AI shapes smooth vehicle user experience with Small Language Models - today

Dr. Johannes Richenhagen･Tobias Schafer･Dr. Dirk Macke･Jorg Kottig･Alexander Kugler･Thomas Hulshorst (FEV.io)

Generative AI with Large Language Models (LLM) faces challenges regarding latency, privacy, cost, and system and user customization. Small Language Models (SLM) address challenges of LLM with onboard privacy, real-time performance, and vehicle integration, enhancing user interaction.
This technology is demonstrated with an intuitive, user-configurable dashboard on a Software-Defined Vehicle platform, combining SLM and LLM. Spoken language is converted to text, interpreted, formalized and executed. By this, both language model benefits are leveraged for seamless driver companionship.
This enables quick roll-out of AI features at optimum costs, latency, privacy and reliability - paving the road for more AI in Software-Defined Vehicles.

AI-based low pressure fuel pump pressure sensor prediction model by Super TML

TACKOON KIM･JUNYOUNG SHIN･SOOIN LEE (Hyundai Motor)

With the development of on-board AI, we need to think about how to use integrated AI sensors in vehicles. In this paper, we verified whether AI sensors can replace hardware sensors by utilizing sensor information provided to users on behalf of sensor values of low-pressure pumps. We also verified the accuracy of AI sensors by comparing them with actual vehicle driving data. A statistical guide on which sensor values should be used as inputs was also verified.

Study on Prediction of Roof Rack Performance using Data Learning Finite Elements Analysis Technique

Gyuho Shim･Jongheon Lee･Teawon Kim (SECO ECOPLASTIC)

The static load analysis to verify the performance of the aluminum roof rack was performed using data analysis techniques to predict displacement. The evaluation method was to apply a load toward the upper part of the vehicle as one of the lift tests and measure the elastic deformation and permanent deformation after maintaining it for a certain period of time. The analysis data analysis was analyzed. A verification test was conducted to verify the predicted results and compared them with the predicted analysis results. In this way, the reliability of the analysis and test was secured, and the performance of the aluminum integrated roof rack was finally predicted using data analysis techniques. It is believed that it can partially replace tests in the design and development of roof rack products.

Manufacturing Process Technology for LiDAR Covers with Self-Healing

Wanho Son･Teawon Kim･Gyeomson Seong (SECO ECOPLASTIC)

The cover that protects the LiDAR system, a key component in autonomous vehicles, requires high transmittance and durability. Conventional LiDAR covers have the issue of transmittance dropping below 30% when surface damage occurs. This paper presents a technological approach using self-healing polyurethane reaction injection molding, which is more environmentally friendly, offers superior surface quality, and allows for greater thickness compared to conventional spray coating methods. This technology is expected to protect LiDAR covers from damage, thereby contributing to the reliability and stability of autonomous vehicles.

Study on Plastic Materials for FCEV Thermal Management System Components : Comparative Analysis of PA and PP

HYEONGWON PARK･KYUNGHWAN OH･MINGYUN CHUNG･TAEGEUN KIM･KYEONGJUN BAEK･WOOKIL JANG･CHULWAN PARK･JIHYUN LEE･SOOHWAN KIM (Hyundai Motor)

This study investigates the changes in requirements for thermal management systems as vehicles transition from ICE to FCEV. It focuses on plastic materials suitable for FCEVs, considering the potential replacement of traditional PA materials with PP materials. The research evaluates long-term aging and lifespan under antifreeze and heat, safety concerning heating components, and ion leaching properties necessary for maintaining ultra-low conductivity in antifreeze. The findings provide insights into the feasibility of using PP materials in FCEV thermal management systems.

Dynamic Viscoelastic Measurements of Urethane Foam for Vehicle Seats with nonlinear properties

Chihiro Kamio･Rei Asakura･Takao Yamaguchi･Shinichi Maruyama (Gunma University)･Kazuto Hanawa･Tsutomu Iwase･Toshihiko Kozai (SUBARU)･Tatsuo Hayashi･Toshiharu Sato･Hajime Mogawa (NHK Spring)

The characteristics of vehicle seats, which are in direct contact with occupants, significantly influence ride comfort. Urethane foam exhibits both elastic and viscous properties, which vary depending on frequency and temperature. In this study, the nonlinear viscoelastic properties of urethane foam were measured under compressive conditions replicating the actual usage when an occupant is sitting on the seat.

Effect of Different Refractory Structures on the Flammability of Fiber Reinforced Plastics

Yusuke Ishihara･Asami Nakai･Masayuki Okoshi (Gifu University)･Atsushi Yuki･Hiroto Shigeta･Haruhiko Nakamura (DaikyoNishikawa)･Shuhei Yasuda･Junichi Ogawa･Yuki Yamada (Mazda)･Masahiko Shigetsu (Hiroshima University)

Installation of electric components for electrification of automobiles has led to a demand for improved fire resistance of FRP. The objective of this study was to improve the fire resistance of hybrid molded products in which the resin base material is covered with a continuous fiber base material. Hybrid structures were fabricated by selecting materials and surface treatments to provide fire resistance, and their effects on flammability were evaluated by combustion tests.

Strength Improvement of CFRTP by Controlling Fiber Orientation (Effect of Product Shape on Fiber Orientation)

Mutsuki Hamada･Souichiro Nishino (Ibaraki University)･Hidemaru Sootome･Kenta Iwasawa (Industrial Technology Innovation Center of Ibaraki Prefecture)

CFRTP, with its light weight and high rigidity, is finding an increasing number of applications as a structural material. On the other hand, it has been pointed out that disruption of the orientation of carbon fibers during injection molding is a factor in strength reduction. In this study, we report the results of our investigation of the effects of fiber orientation inside injection-molded products and product shape, based on strength evaluations and internal observations using CT scans.

Material Data Enrichment with Machine Learning for the Orthotropic Material Property of the FRP

Masakazu Takeuchi (Celanese)

When designing parts using fiber reinforced plastics, it is necessary to take into account the anisotropic properties caused by fiber orientation, but the burden of measuring the properties required for material modeling is not small, and it is difficult to prepare for all candidate material grades. Therefore, we report the results of our investigation into the use of machine learning to predict anisotropic property values ​​from uniaxial tensile test results.

Optimization for thickness design of polymer parts using machine learning

Hiroshi Asayama･Hirofumi Kishi･Kazuyoshi Baba (DAIHATSU MOTOR)

We propose multiobjective optimization for thickness design of polymer parts in vehicles to achieve both lightweight and thermostability. This method is based on CAE data of polymer parts with controlled gradient of thickness to balance variation and moldability. Surrogate modeling according to this method generate Pareto front to obtain optimal solution regarding weight of polymer parts and heat-threshold temperature to deform them. We have achieved thickness design with weight saving and improved thermostability by using proposed method.

A Study of Haptic Simulator for Virtual Door Open & Close Feeling Test

Jaehoon Chung (Hyundai Motor)･Kiwook Kyung･Jisung Kim (KAIST)

Haptic simulators enable the provision of kinesthetic feedback in a virtual environment. This study used a haptic simulator to produce the force and movement of a car door during opening and closing. Since a car door has many components and various factors influence each other, the relationship between each factor must be accurately modeled to produce the tactile feeling of a car door with a simulator. Therefore, the door opening and closing torque was classified into passive and active torque, and each torque was implemented by a brake and a motor. In addition, door inertia has a significant impact on the door opening and closing feeling and movement, this factor was also implemented to develop hybrid haptic simulator. This shows that it is possible to experience a car door opening and closing feeling in a virtual environment without a physical door.

Customized interior lamp control
by detecting and determining the condition of passengers

SUNG HO PARK (Hyundai Motor)

The main function of the camera in the vehicle is to monitor the carelessness of the driver, such as drowsiness, and it is expected to be mandatory for new cars in the future. The function using the camera is expected to increase to monitor the presence of passengers and health conditions. In this study, the driver's condition is judged based on facial expressions and heart rate by using the camera in the vehicle and the mood lighting, thereby ensuring a safe and comfortable driving environment. It is intended to study a method of controlling a mood lamp that can be constructed.

New Euro NCAP Protocol for General Vehicle Controls: Redefining Safety Standards for Driver Interaction Through Vehicle Design

James D. Jackson (Applus IDIADA)

Driver distraction is recognised by Euro NCAP as a key contributing factor in risks associated with road traffic accidents. As part of the Vision 2030 strategy, a new General Vehicle Controls protocol will aim to encourage vehicle manufacturers to implement good practices which avoid distractions by design. Poor interaction design can contribute to drivers looking away from the road for extended periods, whether performing driving-related tasks or whilst using other vehicle functions. Euro NCAP will reward control design that minimises drivers looking away from the road.
This presentation will explore the following topics relating to the new protocol:
- Premise and background of HMI assessment for vehicle safety
- Development of the protocol, its structure and scope, and definition of the test procedure
- Insights from pilot implementations and guidance to industry from IDIADA experience.

Assessing Driver Engagement in a Driving Simulator

Francesco Deiana･James Jackson･Cristina Periago Linares･Elena Castro Gonzalez (APPLUS+ IDIADA)

The adoption of ADAS at Levels 2 and 3, combined with advanced occupant monitoring systems, has improved vehicle safety and comfort. However, concerns about driver attention and engagement persist, as users may not fully understand system limitations or their responsibility when systems are active. To address this, regulations emphasize "driver engagement" through monitoring, cooperation, and clear communication. IDIADA's Human Factors team developed a methodology tested in proving grounds and now implemented in a dynamic driving simulator. This study, conducted in China with 40 participants, collected subjective, objective, and physiological data, validating the approach and emphasizing the balance between technology and human control for safe systems.

A Study on Optimal Energy use for operating moving parts in vehicle

Seokjin Park･Kyungsup Chun･Jaeyoon Ryoo･Minhyung Byun･Sanghyun Lee (Hyundai Motor)

Operating sensibility refers to actual usability of consumers. There are techniques to evaluate sensibility, but it is based on force-oriented and inadequate to represent various consumers. In addition, property units of each part are different. It means that current techniques lack correlation with consumer sensibility. The purpose of this study is to propose energy evaluation method. First, we present methods that reflect needs of various consumers. Second, based on consumer energy, we determine improvement needs of various parts and suggest goals. Ultimately, all parts can be evaluated based on consumer sensibilities, and performance can be strengthened to secure product value.

Multi-Agent Traffic Simulation and Road Safety Assessment: Current Status and Future Work

Jun Tajima (Misaki Design)･Keisuke Suzuki (Kagawa University)

This paper depicts and clarify the features of the traffic safety assessment by multi-agent traffic simulation by stating that it is essentially a numerical solution of simultaneous stochastic and nonlinear differential equation systems, and by making comparison with the results by the conventional methods such as time-series reliability model. Future issues for the advancement of the methodology will also be discussed.

Analysis of motorcycle rider risk-taking behavior based on emotional state and driver characteristics

Keisuke Suzuki･Naoki Nishiyama (Kagawa University)･Yoshitaka Mimura･Joohyeong Lee (Honda R&D)

A basic analysis was conducted on 30 participants regarding the risk-taking behavior of motorcycle riders, based on emotional states equivalent to neutral and impatient in Russell's Circumplex Emotion Model, and on driver personality traints clustered by DSQ, etc. Furthermore, a methodology for analyzing driving behavior based on these emotional states and the driver's personality traits using multi-agent simulation is outlined.

Development of Mixed-Reality Pedestrian Simulator for constructing pedestrian agent model and Proposition of Simulator Experiment Database for sharing Experimental Raw Data

Keita Oda･Jun Tajima (Misaki Design)･Keisuke Suzuki (Kagawa University)

We present the results of the observation of the interaction between the pedestrian in the Mixed Reality pedestrian simulator, which displays integrated view of real images and computer graphics and allows the pedestrian subjects walk safely, and the driver in driving simulator, which have connected each other. In addition, we discuss and propose the construction of the database to share the time-series data acquired in various simulator tests for more effective research advancement in cooperative areas.

Effectiveness Validation on Highway Merging Support System using Multi-Agent Traffic Simulation and Multiple Driving Simulator Coordination

Tohru Yoshioka (Mazda Motor Corporation, Kagawa University)･Keisuke Suzuki (Kagawa University)･Hironori Suzuki (Toyo University)･Jun Tajima (Misaki Design LLC)

Taking CACC-based support system as an example of highway merging support measures, we investigate the effectiveness of the system on merging performance and driver’s acceptability according to the penetration rate of CACC system using the virtual environment where 10 simulator vehicles can drive simultaneously in simulated traffic flow, developed as a platform to evaluate validity of various highway merging support measures. We also discuss the usefulness of the platform as an evaluation environment.

Design methods for high sense of security visibility support devices
-Utilization of multi-agent simulation Re:sim-

TAKUYA IZUMIGUCHI･KENTO MERA･HIDEKI SHINSAKA･SEISHI TAKAGI･KAN KOUNO (PENSTONE)･KOKI MIYAMOTO･TOHRU YOSHIOKA･KEISUKE SUZUKI (Kagawa University)

The effect of the visual information by the digital rear-view display on the create a sense of security was evaluated by using multi-agent driving simulator. From the results, we gained insight into the proper field of view angle, attachment position of the camera and visual information leading to predictive driving, which would help drivers to change lanes in more safe manner.

Proposal and Effectiveness Test of Electric Kickboard Metacognitive Driving Education

Rintaro Yoshikawa･Keisuke Suzuki (Kagawa University)･Kensuke Umazume (Aioi Nissay Dowa Insurance Co., Ltd.)

We proposed a metacognitive driving education program specifically designed for electric kickboards to reduce traffic accidents. In order to clarify the validity of this driving education method, we developed our own VR simulator for electric kickboards and conducted a subject experiment with 30 experimental participants. Specifically, subjects were encouraged to drive safely by using quantitative values of driving skills and a bird's-eye view that allowed them to look back at their driving objectively from a third-person perspective. As a result, we confirmed an average improvement of approximately 22% in driving ability and 14% in meta-cognitive ability.

Study on Virtual Test Platform by utilizing Multi-agent Traffic Simulation for Sophisticated Automated Driving System Development

Sou Kitajima･Shun Endo･Nobuyuki Uchida･Kunio Yamazaki (JARI)･Naoki Suganuma (Kanazawa University)･Tadashi Okuno (OS Planning)･Jun Tajima (Misaki Design)

This paper describes an effective virtual test platform to develop more sophisticated Automated Driving System by generating both complicated and perplexing scenarios. Because it is difficult to find and accumulate these scenarios through field operational test, an enhanced function is developed and implemented our multi agent traffic simulation. The platform enables not only to provide significant variation of extracted rare scenarios but also to realize decision making improvement of Automated Driving System by efficient training for proficient interaction with other traffic participants.

Unified Path Planning Algorithm for Traffic Participants in Multi-Agent-based
Simulation and Its Parameter Estimation from Actual Data

Hironori Suzuki (Toyo University)･Jun Tajima (Misaki Design)

We propose a discrete-choice-based path planning algorithm that can be uniformly applied to vehicles, motorcycles, pedestrians, bicycles, and other traffic participants appears in the multi-agent traffic simulation. We also describe an estimation method of parameters in the path planning algorithm. The effectiveness of the proposed scheme is verified using the behavior data obtained from a simulator.

Multi-Agent Traffic Simulation based on Dashboard Camera Images
-Development of 3D Position Reconstruction Technology utilizing Digital City Models-

Toshiya Arakawa (Nippon Institute of Technology)･Jun Tajima (Misaki Design LLC.)･Hironori Niwa (nitro LLC.)

The technology to reproduce recorded traffic situation by multi-agent simulation based on the video images of Dashboard Camera would be becoming increasingly important in various application areas. This paper describes the significance of this technology and proposes a method to improve the accuracy of estimation of position, orientation etc. of traffic participants by utilizing a matching technique of the images, between the one created from digital city model and the other recorded Dashboard Camera image.

Acquisition and analysis of simulator driving data in the naturalistic traffic flow generated by multi-agent traffic simulation by the same subject over months

Toshiaki Kimura (Kyoto Tachibana University)･Hironori Suzuki (Toyo University)･Jun Tajima (Setouchi Simulator)

We present the results of an investigation of changes in driving behavior, subjective evaluation, and unconscious attitude to the traffic safety obtained from the simulator experiment in which the same subject drives the driving simulator for several months in naturalistic traffic flow generated by multi-agent traffic simulation. Also the comparative discussion is made with conventional condition-controlled and short-duration simulator testing methods and proposed naturalistic and long-duration simulator testing method shown in this paper.

Analysis of Factors Leading to "Abandoning Cars" During Disaster Evacuations

Haruto Masubuchi (Nippon Institute of Technology)･Kousuke Aoyama (formerly: Nippon Institute of Technology)･Toshiya Arakawa (Nippon Institute of Technology)

During the Great East Japan Earthquake, traffic congestion caused by vehicle evacuations led to situations where evacuees were caught in the tsunami. This study conducted simulator-based experiments to analyze factors influencing vehicle abandonment during tsunami evacuations. A tendency to abandon vehicles in conformity with preceding vehicles was observed. Additionally, it was shown that displaying the tsunami arrival time was not a direct factor influencing vehicle abandonment.

Managing automaker's legal risks in traffic accidents of autonomous driving,using Multi-Agent Traffic Simulation

Naohiro Tomochika (Mominoki Tomochika Law Firm)

When automakers assign values ​​to the programs of autonomous vehicles, they need to interpret the technical standards for autonomous driving devices. In order to manage legal risks in traffic accidents caused by their autonomous vehicle, they must be able to prove the legitimacy of the values and the legitimacy of the interpretation process. This paper considers interpretation methods that meet these demands.