Patent ID: 7389851
Filing Date: 2008-06-24
Classification: B62D

Abstract:
1. An electric power steering apparatus controlling an operation of an electric motor by a control unit on the basis of a torque signal from a torque sensor and executing a steering assist of a steering shaft via a reduction mechanism, wherein the control unit is provided with a power supply voltage detecting means for detecting a power supply voltage signal of an in-vehicle power supply, and an output inhibiting means for inhibiting an output in multiple stages on the basis of a power supply voltage detected by the power supply voltage detecting means, a maximum driving current of the electric motor is limited at a time when the power supply voltage is decreased by the output inhibiting means so as to reach a first reference value (V 1 ), a motor control output gain is decreased at a time when the power supply voltage reaches a second reference value (V 2 ), and the output is turned off at a time when the power supply voltage reaches a third reference value (V 3 ).