Patent ID: 6892120

Claim:
An electric power steering apparatus comprising: a torque sensor for detecting steering torque applied on a steering member of a vehicle; a first control unit for outputting a first control signal to drive a motor for steering assist, based on the steering torque detected by said torque sensor; a steering angle sensor for detecting a steering angle of said steering member; a norm steering unit for outputting a norm steering angle, based on a norm steering model which defines the relation between the steering torque and the norm steering angle; a second control unit for outputting a second control signal to drive said motor in order to reduce the difference between the norm steering angle outputted from said norm steering unit based on the steering torque and the detected steering angle; and a first changing unit for switching between said first control signal and said second control signal; wherein said norm steering unit has plural kinds of norm steering model, and further comprising a second changing unit for switching said plural kinds of norm steering model.