Controller of electric power-assist steering system

摘要

The present invention discloses a controller of an electric power-assist steering system including a torque detector for detecting a torque applied with a steering wheel that steers a steering system; a steering status determining section for determining a steering status of either turn or return of a steering wheel; and a motor controlling unit for driving a motor in accordance with a target current value calculated based on at least a torque value from the torque detector and the steering status of either turn or return of the steering wheel from the steering status determining section, wherein the motor controlling unit sets a target current value right after a time when the steering status is switched between turn and return to be substantially equal to an actual current value right before a time when the steering status is switched between turn and return.