Controller for power steering apparatus

Abstract

A controller for a power steering apparatus in which operation fluid for generating assist torque is pumped by a motor-driven pump. The controller controls the flow rate of the operation fluid by changing the voltage supplied to the motor. The controller is provided with a section for generating a target value representing a target voltage to be supplied to the motor, a section for detecting the voltage actuary supplied to the motor, and a section for generating a voltage compensation value based on the detected voltage. The voltage compensation value is obtained by integrating a voltage difference between the target voltage and the detected voltage. The voltage compensation value is added to the target value to obtain a compensated target value. The motor is driven by a voltage corresponding to the compensated target value. In another type of controller, a voltage following rate indicating a target variation in voltage is increased to increase the voltage supplied to the motor only when the voltage difference increases. With this, responsiveness can be increased without causing overshoots.