Control device for a motor-driven power steering system of a motor vehicle

摘要

A control device for a motor-driven power steering system of a motor vehicle serves to prevent a clutch producing activation noises without adversely affecting the reliability of the steering system. A power calculation/driver device (91) calculates a motor current instruction value (I0) on the basis of a vehicle speed (V) and a steering torque (T) in order to drive a motor (13). An arithmetic device (901) for a decision reference value for a non-normal torque calculates a decision reference value (T0) for a non-normal torque and a reference time (t0) as a function of the vehicle speed (V) while a load torque calculation device (902) calculates a load torque (TL) on the basis of the steering torque (T) and the motor current instruction value (I0). A motor rotation decision device (907) determines a rotational speed (NM) of the motor (13) from a motor regeneration voltage. If the load torque (TL) is greater than the decision reference value (T0) for a non-normal torque and if its duration (tL) is greater than the reference time (t0), the power supply for the motor (13) is interrupted while a motor fault monitoring/control device (904) is being controlled, on condition that the rotational speed (NM) is not greater than a motor-disabling decision reference rotational speed (N0). Furthermore, a clutch control device (92B) ... in such a way ... Original abstract incomplete. <IMAGE>