Electric power steering mechanism control method and electric power steering mechanism

摘要

The electric power steering mechanism restricts a drive power supplied to a motor to less than a predetermined value if it detects a period of more than 200mS in which the condition (2) that there is no change in the rotation angle of the rotation angle sensor and the condition (1) that the steering torque is over 7Nm are satisfied at the same time. Consequently, torque generated by the motor is reduced, so that if end contact state is present, a rack shaft is returned in an opposite direction to the rack end by a reaction of a tire and as a result, a steering shaft is rotated, thereby the motor and the rotation angle sensor being rotated. That is, it is detected that the end contact state is present if there is a change in the rotation angle (Yes in (4) due to decrease in the drive power and that the motor remains stopped due to other reason if there is no change in the rotation angle (No in (4)).