Controller of electric power-assist steering system

摘要

The present invention discloses a controller 50 of an electric power-assist steering system 100 including a torque detector 30 for detecting a torque applied with a steering wheel 2 that steers a steering system; a steering status determining section 52 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 calculate 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 52, 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".