Electric power steering apparatus

摘要

An electric power steering apparatus having a control unit for controlling a motor for applying an assist torque to a steering system on the basis of a steering torque of the steering system. The control unit has a drive signal fading part for generating a drive current signal on the basis of a deviation signal expressing the deviation between a target current set in correspondence with a steering torque and a detected motor current detected by a motor current detector and gradually decreasing a drive current value with time to zero when a fadeout request signal is supplied to it. Thus in an electric power steering apparatus constructed to gradually decrease a steering assist force being supplied from a motor when an ignition switch is turned off, even if an error arises in a detected motor current value as a result of a fall in the voltage of a battery power supply, the steering assist force can be decreased correctly.