| 摘要 |
PROBLEM TO BE SOLVED: To provide excellent steering assist torque according to a vehicle speed, even when a vehicle speed sensor fails. SOLUTION: A yaw gain map showing a relation between yaw gain G showing the size of a yaw rateγto a steering angleθand the vehicle speed is stored in advance. When a vehicle speed sensor fails, the yaw rateγand the steering angleθare detected and the yaw gain map is referred to, to calculate estimated vehicle speed Vs. A gradual variation processing is performed for the estimated vehicle speed Vs to calculate final corrected estimated vehicle speed Vsx. By referring to an assist torque map by using the corrected estimated vehicle speed Vsx instead of the vehicle speed V detected by the vehicle speed sensor, target assist torque is set. As a result, excellent steering assist torque is obtained. COPYRIGHT: (C)2010,JPO&INPIT |
