APPARATUS FOR ESTIMATING ANGULAR VELOCITY OF DC MOTOR FOR USE IN ELECTRIC POWER STEERING SYSTEM

摘要

An apparatus for estimating angular velocity of a DC motor in an electric power steering system is provided to reduce an error by changing an internal resistance value and an electromotive voltage constant according to a motor thermal table. An apparatus for estimating angular velocity of a DC motor in an electric power steering system comprises an ECU(Electronic Control Unit)(320) for estimating the angular velocity of the DC motor by using a motor plus voltage, a motor minus voltage, a motor current and a motor thermal table(316). The ECU estimates the angular velocity of the DC motor by changing an internal resistance value and an electromotive voltage constant according to the motor thermal table if the temperature of the DC motor is changed by monitoring the temperature of the DC motor.