Development of a Functional Safety Test Environment for Steer-by-Wire Systems Using Vehicle-in-the-Loop Simulation

Seonghun Kim･Seungmin Kwon･Yong-Sub Yi･Hyoungjun Ahn･Giin Jang･Hanjun Cho･Minwoo Han (Hyundai Motor)

This paper presents a new approach for evaluating the functional safety of a SbW(Steer-by-Wire) system, focusing on creating an efficient and safe testing environment for drivers. It introduces the Vehicle-in-the-Loop Simulation (ViLS) using the Handling Roadway (HRW) test rig to assess the functional safety of SbW system. The study validates the correlation between ViLS and proving ground results, analyzes deviations in test results, and suggests methods to improve the efficiency of ViLS testing. These solutions establish criteria for the Fault Tolerant Time Interval (FTTI) and hazard standards, which are applied to the development process of SbW systems.

Active Safety for Farm Tractor based on Nonlinear Dynamics
-Visualization of Tractor Rollover Accident Mechanism using a Tractor Simulator-

Kenshi Sakai (Tokyo University of Agriculture and Technology)

In agricultural tractors, typical deterministic chaos such as sub-harmonic resonance and/or stick-slip occur due to the collision/friction process between the tires and the road surface. The 120 annual fatal accidents caused by agricultural vehicles is the greatest risk to the sustainability of agriculture and food production. For active safety measures, we developed a tractor simulator to visualize the mechanism of tractor overturning accidents.

A Study on the Interior Conditions of a Route Bus that Lead to Passenger Injury Accidents Inside the Vehicle

Chiharu Kato･Tetsuya Hirota･Takeshi Sawada･Toshinari Nakai (Tokai Rika)･Yuta Uchimura･Tadashi Kosugi･Takashi Iwata (Kawasaki Tsurumi Rinko Bus)

Every year, about 300 passenger injury accidents inside route buses occur across Japan. To reduce the number of accidents, bus drivers are required to announce safety reminders to passengers thoroughly via microphone and diligently check the interior mirror. This has led to an increased burden on the drivers.
In this study, we collected video data from inside a route bus operating in Kawasaki City, and analyzed behaviors that could potentially lead to passenger injury accidents.

Study on Strength Estimation of Spot Weld and Efficient Data Expansion Method using Gaussian Process

Taisei Akagi (Hiroshima University)･Yuki Okumoto･Akira Naito･Kosuke Kojima (Mazda)･Yoshikazu Tanaka (Hiroshima University)

The spot weld strength is directly related to the strength of car bodies. However, it is time and labor intensive to acquire data of spot weld strength from fracture tests due to the large number of conditions. In this study, a prediction model using Gaussian process is developed and a data expansion method that can numerically determine additional test conditions necessary for estimating strength accurately is investigated to save labor in acquiring the data.

Multi-Step Shape Optimization Method using Isogeometric Analysis

Mizuki Hoshino (University of Yamanashi)･Shin-ichi Arimoto･Kosho Kawahara (Toyota Motor)･Ki-ichi Furuhashi･Kyohei Noguchi･Yuta Yokoyama･Hirofumi Sugiyama･Shigenobu Okazawa (University of Yamanashi)

To achieve global shape optimization using Isogeometric Analysis, we develop a scheme that automatically repeats optimization and changes the number of control points. By updating the number of control points and search area step by step, the design space can be widely explored while avoiding shape breakdown. Evaluate the performance of the derived structure using example calculations.

Development of Triboelectric Power Generator Mounted in Tire for Tire Pressure Monitoring System

Hiroshi Tani･Shinji Koganezawa･Shohei Kawada･Renguo Lu (Kansai University)

A triboelectric power generator that can be attached to a tire was developed as a power source for a tire pressure monitoring system (TPMS). The structure of the generator was determined according to the size of the tire, and power generation of more than 200 μW was confirmed at speeds of 20 to 80 km/h during actual driving. The operation of the TPMS was also confirmed.