Motor driving control device and motor driving control method

Patent metadata

Field	Value
Publication number	US-10790768-B2
Application number	US-201916282518-A
Country	US
Kind code	B2
Filing date	Feb 22, 2019
Priority date	Sep 1, 2016
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

A rotational stop position of a motor is accurately controlled. A motor driving control device ( 100 ) includes a BEMF detection unit ( 118 ) for detecting zero-cross of back electromotive force of a motor coil provided in a motor, and a CPU ( 101 ) for controlling driving of the motor by a 1-phase energization method and, without a position sensor, performing commutation based on the zero-cross of the back electromotive force detected by the BEMF detection unit ( 118 ), controlling driving of the motor based on a rotational speed corresponding to a drive voltage and a load, and performing extension control of a commutation time for each step from a calculated deceleration start step until the rotational speed of the motor decreases to a predetermined rotational speed or less for enabling the motor to stop at a desired stop position when the driving of the motor is stopped.

First claim

What is claimed is:

1. A motor driving control device comprising:
a zero-cross detection unit configured to detect zero-cross of back electromotive force of a motor coil provided in a motor; and
a control unit configured to:
control driving of the motor by a 1-phase energization method by position sensorless driving,
perform commutation based on the zero-cross of the back electromotive force detected by the zero-cross detection unit,
control driving of the motor based on a rotational speed corresponding to a drive voltage and a load of the motor, and
perform extension control of a commutation time for each step of the motor from a calculated motor deceleration start step until the rotational speed of the motor decreases to a predetermined rotational speed or less, such that the motor is configured to stop at a desired stop position when the driving of the motor is stopped.

2. The motor driving control device according to claim 1 , wherein the control unit performs control of ceasing the commutation based on the zero-cross of the back electromotive force from the deceleration start step until the motor is equal to or lower than the predetermined rotational speed to extend the commutation time for each step.

3. The motor driving control device according to claim 2 , wherein the control unit increases the commutation time for each step at a constant rate.

4. The motor driving control device according to claim 1 , wherein the deceleration start step is calculated based on a number of driving steps and a number of deceleration steps.

5. The motor driving control device according to claim 1 , further comprising an H-bridge circuit combining half bridges connected to the motor coil, and a current detection unit configured to detect a motor current flowing through the motor coil, wherein the control unit specifies a slow decay mode to the H-bridge circuit at every PWM cycle when the motor current detected by the current detection unit exceeds a predetermined current value during a period from the deceleration start step until the motor is stopped.

6. The motor driving control device according to claim 5 , wherein the control unit repeats a charge mode and the slow decay mode as an operation mode under current limitation.

7. The motor driving control device according to claim 6 , wherein the control unit performs transition in order of a shoot through protection mode, a flyback mode, and a free mode after repetition of the charge mode and the slow decay mode at every PWM cycle as the operation mode under current limitation.

8. A motor driving control method comprising:
detecting zero-cross of back electromotive force of a motor coil provided in a motor; and
controlling driving of the motor by a 1-phase energization method, by position sensorless driving;
performing commutation based on the detected zero-cross of the back electromotive force;
controlling driving of the motor based on a rotational speed corresponding to a drive voltage and a load of the motor; and
performing extension control of a commutation time for each step of the motor from a calculated motor deceleration start step until the rotational speed of the motor decreases to a predetermined rotational speed or less, such that the motor is configured to stop at a desired stop position when the driving of the motor is stopped.

Assignees

• Minebea Mitsumi Inc

Inventors

• Hijikata Hidetoshi

Classifications

• H02P6/182 Primary

  using back-emf in windings · CPC title

• H02P6/20

  Arrangements for starting (H02P6/08 takes precedence) · CPC title

• H02P8/24

  Arrangements for stopping (H02P8/32 takes precedence) · CPC title

• H02P8/14

  Arrangements for controlling speed or speed and torque (H02P8/12, H02P8/22 take precedence) · CPC title

• H02P6/24 Primary

  Arrangements for stopping · CPC title