Patent ID: 6450287
Filing Date: 2002-09-17
Classification: B62D

Abstract:
An electric power steering controller for a vehicle with a steering wheel coupled by a steering assembly to tires steered by the steering wheel, the controller controlling a motor generating a torque for assisting turning of the steering wheel by a driver of the vehicle and comprising:a road reaction torque detector for sensing a road reaction torque received by the tires from a road contacting the tires, the road reaction torque tending to return the steering wheel to a starting point; a returning torque compensator for computing a returning torque for returning the steering wheel to the starting point, based on the road reaction torque and a friction torque of the steering assembly coupling the tires to the steering wheel, the returning torque being provided when a steering torque approaches zero to compensate for the friction torque; and a motor current decision unit for determining a motor current to be fed to the motor, based on at least the returning torque computed by said returning torque compensator, to assist the driver in returning the steering wheel to the starting point.