Electric power steering apparatus

摘要

Steering torque sensor detects steering torque manually applied to the vehicle's steering system. Control unit sets a target motor current corresponding at least to the steering torque detected by the steering torque sensor and has a plurality of steering assist modes to which are allocated different characteristics of a target motor current for an assisting motor. The control unit include a mode switching unit that, in response to a mode setting instruction from a vehicle operator, effects a change between the steering assist modes when the steering torque sensor is in its dead zone and no target motor current signal is being generated. Thus, the driver is allowed to continue driving with a steering characteristic fitting his or her preference, and hence good steering feel and vehicle behavior, even when a steering characteristic change takes place during travel of the vehicle.