Koyo Seiko Company, Ltd.

Hiroki Amako

Hirofumi Matsuoka

Mitsuhiko Nishimoto

An electric power steering apparatus which is provided with a CPU for outputting a drive control signal of an electric motor for assisting the steering force on the basis of the detected steering torque, and a drive inhibition circuit for outputting a signal to stop the operation of the electric motor when the direction of the electric motor operation and the direction of the detected steering torque are opposite to each other, the output of the drive inhibition circuit is inputted to the CPU, which monitors the normal or abnormal condition of the drive inhibition circuit. While the abnormal condition of the CPU continues for a predetermined time period, the drive stop condition of the electric motor is kept. When the detected torque is not smaller than the predetermined value, the drive of the electric motor in the direction opposite to that of the detected torque is inhibited.

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Kashiwara, Japan

Hiroki Amako