| 摘要 |
PROBLEM TO BE SOLVED: To provide a controlling method for an electric power steering of an automobile having a resembling merit to that of hydraulic type in the steering feeling of the electric power steering and having a converging characteristic at high speed running of a vehicle. SOLUTION: It is detected by a steering torque sensor whether steering operation is at the turning or returning. If it is at the turning, a reference current is generated by the sensor and a vehicle speed sensor to thereby drive a motor to support steering operation. If it is at the returning, a decreased quantity of steering torque at the returning is differentiated by a differential current computation circuit 6, then the differentiated value is multiplied by those K1, K2 obtained by converting a motor angle speed sensor value into a specified gain, thereby obtaining a differential current, which is added to the reference current to serve as an assist current by which the motor is driven. Accordingly, a hysterisis characteristic is given to the assist current supporting driving the motor, resulting in improved steering feeling. |
