Patent ID: 9325260
Filing Date: 2016-04-26
CPC Classification: F16H,H02P

Claim Text:
1. A motor control apparatus comprising: a motor having plural phases for driving a control object; a current sensor for detecting a current flowing to the motor; and a control unit including a reference position learning section for learning a reference position by performing a butting control, which rotates the motor until the control object butts a limit position in a movable range of the control object, wherein: the reference position learning section drives the motor for rotation in the butting control by sequentially switching over a current supply phase of the motor in a current supply method, in which the number of the current supply phase of the motor, to which the current is supplied at same time, is fixed thereby to suppress torque change in the motor caused by switchover of the current supply phase so that the value of torque of the motor is controlled to a substantially constant value, while performing a constant current control for controlling a sum of currents flowing in respective phases of the motor to a constant value based on an output of the current sensor; and the control object is a shift range switchover mechanism, which switches over shift ranges of an automatic transmission system.