a control unit for setting {HEAD ~ a target motor current} on {TAIL ~ the basis} of at least the steering torque detected by said steering torque sensor 
on
a control unit for setting { HEAD ~ a target motor current } on { TAIL ~ the basis } of at least the steering torque detected by said steering torque sensor
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH