Fuji Xerox Co., Ltd.

Fujifilm Business Innovation Corp.

Toyohiko Hoshino

Yukitoshi Takano

Motohiro Tokairin

Hitoshi Mikami

Yukio Kontani

A control apparatus includes a controller that controls, by vector control, voltages and currents to be supplied to plural phases of a brushless motor. The vector control is performed through rotation control using a q-axis current predominantly to control rotation of a rotor, and field fixing control using a d-axis current predominantly in response to reception of a stop command signal. The controller controls the brushless motor with reduced influence of a dead time, in which a high-side switching element and a low-side switching element of each of plural half-bridge circuits are simultaneously set to OFF. The plural half-bridge circuits are provided in association with the plural phases of the brushless motor and are configured to supply the voltages and the currents to the respective phases. The influence of the dead time is reduced through the field fixing control.

Control apparatus and brushless motor

A control device includes an obtaining unit that obtains rotation information indicating an amount of rotation and a rotation direction of a rotor of a brushless motor; and a controller that specifies a current to be provided to a coil of the brushless motor to control a rotating magnetic field generated by the coil by performing change control for gradually changing an electrical angle of the rotating magnetic field, detecting, as an initial position of the rotor, a position in which the rotor faces magnetic poles generated at an electrical angle when the rotation direction obtained during the change control changes from a first direction to a second direction and a difference between the amount of rotation in the first direction and that in the second direction obtained during the change control becomes smaller than a first threshold, and controlling the rotating magnetic field in accordance with the initial position.

Growing community of inventors

Kanagawa, Japan

Toyohiko Hoshino