Patent ID: 6116372
Filing Date: 2000-09-12
Classification: B62D

Abstract:
An electric power steering apparatus for an automotive vehicle having a steering system, the electric power steering apparatus comprising:an electric motor for applying an electric steering assist to the steering system of the automotive vehicle;a steering torque sensor for detecting steering torque manually applied to the steering system;a control unit in communication with the steering torque sensor, wherein the control unit sets a target motor current corresponding at least to the steering torque detected by said steering torque sensor, said control unit having a plurality of steering assist modes to which are allocated different characteristics of the target motor current; anda drive in communication with the control unit and the electric motor for driving said electric motor in accordance with a motor control signal generated by said control unit on the basis of the target motor current;the control unit including a mode switching unit wherein the mode switching unit, in response to a mode setting instruction from a vehicle operator, effects a change between the steering assist modes when said steering torque sensor is in its dead zone.