Electric motor system and motor control method

A method of driving a motor, the method comprising:

• outputting, at a controller, a control signal for controlling a DC motor, the control signal being based on a rotation signal output with rotation of a rotating shaft of the DC motor;
• and
• changing a gain used by the controller from a first gain used by the controller in a state other than a hold state into a second gain smaller than the first gain if, in the hold state in which position of the DC motor is held while being energized, a positional deviation between a position of the DC motor based on the rotation signal and a stopping position becomes smaller than a threshold for a period of time.

A non-transitory computer readable storage medium having a executable program stored thereon that, when executed by a controller that outputs a control signal for controlling a DC motor based on a rotation signal output with rotation of a rotating shaft of the DC motor, configures the controller to,

• change a gain used by the controller from a first gain used by the controller in a state other than a hold state into a second gain smaller than the first gain if, in the hold state in which position of the DC motor is held while being energized, a positional deviation between a position of the DC motor based on the rotation signal and a stopping position becomes smaller than a threshold for a period of time.