Patent ID: 6032756
Filing Date: 2000-03-07
Classification: B62D

Abstract:
A motor-driven power steering system for a motor vehicle, comprising:steering torque detecting means for detecting a steering torque applied to a steering wheel by a driver;an electric motor for applying an assist torque to a steering mechanism for thereby assisting the driver in steering operation;control means for outputting a motor driving signal for driving said motor in dependence on the output of said steering torque detecting means;interlock means for enabling or inhibiting a driving direction of said motor in dependence on the output of said steering torque detecting means;motor driving means for driving said motor in the direction enabled by said interlock means in accordance with said motor driving signal while disabling driving operation of said motor in a direction inhibited by said interlock means; andmotor current detecting means for measuring a current flowing through said electric motor,wherein a threshold value referenced by said interlock means in decision for enabling or inhibiting the driving direction of said motor is changed in accordance with said detected value of said motor current.