CONTROL METHOD FOR ELECTRIC POWER STEERING DEVICE

摘要

PROBLEM TO BE SOLVED: To prevent steep change in the steering torque in the event of failure in an abnormal vehicle behavior sensing means in an arrangement where a control to suppress abnormal behavior is conducted by an electric power steering device. SOLUTION: When abnormality in vehicle behavior is sensed by a vehicle behavior sensing means to sense the behavior of a vehicle, a steering reaction force is generated so as to suppress the abnormality in behavior by a motor which is to generate an assist force for driving the steering vehicle wheel in compliance with the turning angle of a steering wheel. In this electric power steering device, the steering reaction force is decreased gradually in case any failure in the vehicle behavior sensing means is detected. This leaves the component of assist force to allow suppressing a steep change in the steering torque, and it is possible to suppress change in the feeling in the steering operation before and after occurrence of failure as much as practicable.