Motor driving control device and motor driving control method

Patent metadata

Field	Value
Publication number	US-10917028-B2
Application number	US-201916509679-A
Country	US
Kind code	B2
Filing date	Jul 12, 2019
Priority date	Jul 20, 2018
Publication date	Feb 9, 2021
Grant date	Feb 9, 2021

Abstract

A motor driving control device has a motor driving unit configured to selectively energize coils with a plurality of phases of a motor, a control circuit unit configured to control an operation of the motor driving unit by outputting a driving control signal to the motor driving unit, and a position detector configured to output a position signal which corresponds to any one phase of the plurality of phases and a phase of which changes depending on a position of a rotor of the motor. the control circuit unit detects a transition of values of a back electromotive force induced in the one phase in a detection period corresponding to a change timing of the position signal when beginning to start up the motor, and determines a rotational state of the motor including a rotational direction of the motor based on a detection result of the transition of the values of the back electromotive force.

First claim

What is claimed is:

1. A motor driving control device comprising:
a motor driving unit configured to selectively energize coils with a plurality of phases of a motor;
a control circuit unit configured to control an operation of the motor driving unit by outputting a driving control signal to the motor driving unit; and
a magnetic sensor provided at a position corresponding to any one phase of the plurality of phases and configured to output a position signal whose phase changes depending on a positional relationship between the one phase of the plurality of phases and a rotor of the motor to the control circuit,
a voltage dividing circuit electrically connected between an energization line to any one phase of the plurality of phases and a ground and configured to output a potential corresponding to a back electromotive force generated in the one phase to the control circuit when the energization by the motor driving unit is not performed,
wherein the control circuit unit includes;
a timing signal generation unit configured to set a detection period corresponding to a timing of a change of the position signal being input from the magnetic sensor when beginning to start up the motor such that a length of the detection period becomes a length corresponding to a cycle of the position signal,
a voltage detection unit configured to detect a plurality of values of the back electromotive force based on the potential corresponding to the back electromotive force inputted from the voltage dividing circuit during the detection period corresponding to the timing of the change of the position signal,
a voltage transition calculation unit configured to determine whether the motor is rotating forward, is rotating backward, or is neither rotating forward nor rotating backward based on whether the values of the detected back electromotive force tend to increase, tend to decrease, or neither tend to increase nor tend to decrease in the detection period.

2. The motor driving control device according to claim 1 ,
wherein the timing signal generation unit sets the detection period to start after the change of the position signal and end before a time period equal to one-fourth of the cycle of the position signal elapses.

3. The motor driving control device according to claim 1 , wherein the timing signal generation unit sets an average value of a continuous plurality of cycles of the position signal to the cycle of the position signal.

4. The motor driving control device according to claim 1 ,
wherein the voltage transition calculation unit detects the transition of the values of the back electromotive force in each of a plurality of different detection periods when beginning to start up the motor, and determines a rotational state of the motor based on a detection result of the transition of the values of the back electromotive force in each of the plurality of different detection periods.

5. The motor driving control device according to claim 1 ,
wherein the control circuit unit further includes a energization system command unit configured to determine a driving control method subsequently performed based on a determination result of the rotational state of the motor.

6. A motor driving control method for a motor having coils with a plurality of phases, the motor driving control method comprising:
a step for setting a detection period corresponding to a timing of a change of a position signal which is output from a magnetic sensor provided at a position corresponding to any one of the plurality of phases and whose phase changes depending on a positional relationship between the one phase of the plurality of phases and a rotor of the motor when beginning to start up the motor such that a length of the detection period becomes a length corresponding to a cycle of the position signal;
a voltage dividing step for outputting a potential corresponding to a back electromotive force generated in the one phase when an energization by the motor driving unit is not performed;
a back electromotive force detection step for detecting a plurality of values of the back electromotive force induced in the one phase during the detection period based on the potential corresponding to the back electromotive force inputted in the voltage dividing step during the detection period corresponding to the timing of the change of the position signal; and
a rotational state determination step for determining whether the motor is rotating forward, is rotating backward, or is neither rotating forward nor rotating backward based on whether the plurality of the values of the back electromotive force detected in the back electromotive force detection step tend to increase, tend to decrease, or neither tend to increase nor tend to decrease in the detection period.

Assignees

• Minebea Mitsumi Inc

Inventors

• Zhou Xiao
• Kaidu Hiroyuki
• Aoki Masato
• Terada Mitsunari

Classifications

• H02P6/22 Primary

  in a selected direction of rotation · CPC title

• H02P6/182 Primary

  using back-emf in windings · CPC title

• H02P6/157

  wherein the commutation is function of electro-magnetic force [EMF] · CPC title