Tohru Yoshioka

Application of sliding-mode theory to direct yaw-moment control

Abstract It has become popular to control vehicle manoeuvering with independent brakes for the avoidance of spin and drift-out. To ensure effective control, we applied sliding-mode theory, which enabled a robust control system against various driving conditions including changes in velocity, road friction and vehicle weight. By estimating the tyre status with a simple tyre model, the side slip angle of vehicle and road friction, we made it possible to easily install the system on vehicles. Our system is also equipped with parameter identification for correcting model errors. We confirmed the effectiveness of our system through full vehicle simulation and field tests.

Measurement of vehicle attitude with RTK-GPS for analyzing the vehicle motion behavior

Elucidating the relation between the phenomena evaluated by the test driver subjectively and objective data is important in the development of the steering and handling performance of the vehicle. For this purpose, we have developed a system, which estimates the 6-DOF movement of a vehicle based on the vehicle angular velocities around its three axes and the positions through plural real-time-kinematic-GPS (RTK-GPS) on the vehicle. The rotation axis of the body is defined based on the results estimated by the system, and the difference is observed in the rotation axis corresponding to the difference of subjective evaluation.

Introduction of the Mazda Advanced Safety Vehicle

Mazda has developed Mazda ASV based on two technological themes; precautionary safety technologies which help reduce drivers error through an enhanced human interface between the vehicle and the driver, and accident avoidance technologies which function as a back-up in case of careless mistakes. Mazda focused on the facts that the mistakes of careless drivers have been the cause of the greater part of accidents and that about twenty percent of traffic deaths have happened while pedestrians cross streets. To help solve these problems, Mazda actively takes part in the Study Group for Promotion of ASV (Advanced Safety Vehicle) headed by the Japanese Ministry of Transport, and researches and develops advanced safety technologies. This paper introduces the concept of accident prevention based on the analysis of traffic accidents and the accident avoidance technologies we developed and installed on Mazda ASV.