Electric motor system and motor control method

摘要

An electric motor system includes a brushless direct-current motor, a driver circuit, a position sensor, and a control circuit. The motor has an output shaft for transmitting torque. The driver circuit supplies power to the motor according to a control signal input thereto. The position sensor measures an angular, rotational position of the motor shaft. The control circuit controls operation of the motor. The control circuit includes a position sensor terminal, a reference terminal, a differential calculator, a controller, and a gain adjuster. The position sensor terminal receives a feedback signal. The reference terminal receives a reference signal. The differential calculator generates an error signal representing a difference between the measured and targeted rotational positions. The controller generates the control signal based on the error signal through a combination of control actions. The gain adjuster is connected to the controller to adjust a gain of each control action.

主权项

1. A control circuit, comprising:
a controller to output a control signal for controlling a DC motor based on a rotational signal output with rotation of a rotating shaft of the DC motor; and a gain setting device 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 a position of the DC motor is held while being energized, 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.