Electric power steering control apparatus

摘要

An electric power steering control apparatus is intended to improve the convergence and control stability of a returning motion of a steering wheel when a driver of a vehicle on which the apparatus is installed lets his or her hands free from the steering wheel, and to reduce a burden to the driver when an excessive steering torque occurs during the returning motion. The apparatus includes a steering torque sensor (8) for detecting a steering torque of a steering system of the vehicle, a motor rotational-speed detector (7) for detecting a rotational speed of the electric motor (1), and a rotational-speed controller for controlling the electric motor based on output signals from the steering torque sensor and the motor rotational-speed sensor so that when the steering torque as detected is less than a predetermined torque value, the rotational speed of the electric motor does not exceed a predetermined speed value corresponding to the predetermined torque value. <IMAGE>