Motor control apparatus, sheet conveyance apparatus, and image forming apparatus

Patent metadata

Field	Value
Publication number	US-10637382-B2
Application number	US-201916262614-A
Country	US
Kind code	B2
Filing date	Jan 30, 2019
Priority date	Feb 16, 2018
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

An apparatus to control a motor includes a detector that detects a driving current flowing through a motor winding, phase determiner that determines a motor rotor rotation phase based on the detected driving current, generator that generates an instructed phase, and controller. The controller includes a first mode where controlling the driving current flowing through the motor winding controls the motor based on a torque current component value such that a deviation between the generated instructed phase and the determined rotation phase is reduced, and a second mode in which a current of a predetermined magnitude controls the motor. The torque current component is expressed in a rotating coordinate system based on determined rotation phase. The generator generates, based on the rotation phase determined while executing second mode, the instructed phase in the first mode when a controlling driving current mode is switched from the second to the first mode.

First claim

What is claimed is:

1. A motor control apparatus to control a motor based on an instructed phase indicating a target phase of a rotor of the motor, the motor control apparatus comprising:
a detector configured to detect a driving current flowing through a winding of the motor;
a phase determiner configured to determine a rotation phase of the rotor based on the driving current detected by the detector;
a generator configured to generate the instructed phase; and
a controller including a first control mode, in which the motor is controlled by controlling the driving current flowing through the winding of the motor based on a value of a torque current component such that a deviation between the instructed phase generated by the generator and the rotation phase determined by the phase determiner is reduced, and a second control mode in which the motor is controlled based on a current of a predetermined magnitude, wherein the torque current component is expressed in a rotating coordinate system based on the rotation phase determined by the phase determiner,
wherein the phase determiner is configured to determine the rotation phase even while the second control mode is executed, and
wherein the generator generates, based on the rotation phase determined by the phase determiner while the second control mode is executed, the instructed phase in the first control mode in a case where a control mode for controlling the driving current is switched from the second control mode to the first control mode.

2. The motor control apparatus according to claim 1 , further comprising a pulse generator configured to generate a pulse train,
wherein the generator updates the instructed phase by adding a predetermined amount of change to the instructed phase each time a pulse of the pulse train output from the pulse generator is input.

3. The motor control apparatus according to claim 2 , wherein, in the case where the control mode for controlling the driving current is to be switched from the second control mode to the first control mode, an initial phase of the instructed phase in the first control mode is set based on the rotation phase determined by the phase determiner while the second control mode is executed.

4. The motor control apparatus according to claim 3 ,
wherein the detector is configured to detect the driving current with a predetermined period,
wherein the phase determiner determines the rotation phase based on the driving current detected by the detector, and
wherein the initial phase of the instructed phase in the first control mode is set based on the rotation phase that is last determined by the phase determiner before the control mode is switched from the second control mode to the first control mode.

5. The motor control apparatus according to claim 2 ,
wherein the controller includes a speed determiner configured to determine a rotation speed corresponding to a target speed of the rotor based on a frequency of the pulse train output from the pulse generator, and
wherein, in a case where the rotation speed determined by the speed determiner exceeds a predetermined value, the controller switches the control mode for controlling the driving current from the second control mode to the first control mode.

6. The motor control apparatus according to claim 5 , wherein the speed determiner is configured to determine the rotation speed corresponding to the target speed each time a pulse of the pulse train is input from the pulse generator.

7. The motor control apparatus according to claim 1 , further comprising an induced voltage determiner configured to determine a magnitude of an induced voltage induced each in a winding of a first phase and a winding of a second phase by rotation of the rotor,
wherein, in a case where the induced voltage determiner determines the magnitude of the induced voltage of the first phase and the magnitude of the induced voltage of the second phase, the phase determiner determines the rotation phase of the rotor based on the magnitude of the determined induced voltage of the first phase and the determined magnitude of the induced voltage of the second phase.

8. The motor control apparatus according to claim 7 , wherein, in a case where the induced voltage determiner determines a magnitude of an induced voltage of the first phase and a magnitude of an induced voltage of the second phase, the predetermined value is set to the rotation speed from which the rotation phase of the rotor of the motor is determinable by the phase determiner based on the determined magnitude of an induced voltage of the first phase and the determined magnitude of an induced voltage of the second phase.

9. The motor control apparatus according to claim 1 , further comprising a storage unit configured to store a phase difference between the instructed phase that is last generated by the generator before the control mode for controlling the driving current is switched from the second control mode to the first control mode and the rotation phase determined by the phase determiner,
wherein, in a case where the control mode for controlling the driving current is to be switched from the first control mode to the second control mode, an initial phase of the instructed phase in the second control mode is set based on the instructed phase that is last generated by the generator before the control mode is switched from the first control mode to the second control mode and the phase difference stored in the storage unit.

10. The motor control apparatus according to claim 1 ,
wherein the detector is configured to detect the driving current with a predetermined period,
wherein the motor control apparatus further includes a second storage unit configured to store the value of the torque current component of the driving current that is last detected by the detector before the control mode for controlling the driving current is switched from the second control mode to the first control mode, and
wherein, in a case where the control mode for controlling the driving current is to be switched from the first control mode to the second control mode, an initial phase of the instructed phase in the second control mode is set based on the value of the torque current component of the driving current that is last detected by the detector before the control mode is switched from the first control mode to the second control mode and the value of the torque current component stored in the second storage unit.

11. The motor control apparatus according to claim 1 , wherein the first control mode is a control mode in which the motor is controlled by controlling a value of an excitation current component of the driving current detected by the detector such that the value is adjusted to zero and by controlling the value of the torque current component of the driving current detected by the detector.

12. The motor control apparatus according to claim 1 , further comprising:
a first control circuit configured to supply the driving current to each of a winding of a first phase of the motor and a winding of a second phase of the motor in a case where the first control mode is executed;
a second control circuit configured to supply the driving current to each of the winding of the first phase of the motor and the winding of the second phase of the motor in the case where the second control mode is executed; and
a switching unit configured to switch between control of the motor using the first control circuit and control of the motor using the second control circuit.

13. A motor control apparatus to control a motor based on an instructed phase indicating a target phase of a rotor of the

Assignees

• Canon Kk

Inventors

• Takatsu Junya

Classifications

• H02P21/22 Primary

  Current control, e.g. using a current control loop · CPC title

• G03G15/80 Primary

  Details relating to power supplies, circuits boards, electrical connections · CPC title

• G03G15/6508

  Automatic supply devices interacting with the rest of the apparatus, e.g. selection of a specific cassette (matching the image with the size of the copy material G03G15/5095) · CPC title

• H02P21/24

  Vector control not involving the use of rotor position or rotor speed sensors · CPC title

• H02P21/18

  Estimation of position or speed · CPC title