Motor control apparatus

• US 20090193923A1
• Filed: 03/19/2009
• Published: 08/06/2009
• Est. Priority Date: 06/03/2002
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Fujiki, Kenichi, Kamio, Shigeru, Nakai, Yasuhiro
• Granted Patent: US 8,013,563 B2
• Time in Patent Office: Days
• US Class Current: 74/473.12
• CPC Class Codes: F16H 2061/326 Actuators for range selection, i.e. actuators for controlling the range selector or the manual range valve in the transmission
• CPC Class Codes: F16H 61/32 Electric motors actuators or related electrical control means therefor
• CPC Class Codes: H02P 25/08 Reluctance motors
• CPC Class Codes: H02P 25/092 Converters specially adapted for controlling reluctance motors
• CPC Class Codes: H02P 25/0925 wherein the converter comprises only one switch per phase
• CPC Class Codes: H02P 8/42 characterised by non-stepper motors being operated step by step
• CPC Class Codes: Y10T 74/2003 Electrical actuator

Abstract

In an automatic transmission position control by a motor, it is determined whether the present instant belongs to a starting period, that is, the present instant is immediately after resetting of a control unit or application of power to it. If it is the starting period, an actual shift position that is detected from an output of an output shaft sensor for detecting a rotation position of a motor is set as an instructed shift position. With this measure, even if the control unit is reset for a certain reason while the vehicle is running, the instructed shift position is not changed in association with the resetting. This prevents trouble that the shift position is switched contrary to the intention of the driver, whereby the reliability of a position switching control can be increased.

Claims

1. A motor control apparatus comprising:

an encoder for producing a pulse output signal in synchronism with rotation of a rotor of a motor;

control means for rotating the rotor to a target position by detecting a rotation position of the rotor on the basis of a count of the output signal of the encoder and sequentially switching a current supply phase of the motor;

reversing monitoring means for monitoring a variation direction of the count of the output signal of the encoder, and determining whether a rotation direction of the rotor has been reversed from a rotation direction toward the target position; and

reversed rotation preventing means for prohibiting current supply for A-phase with which the rotor is driven in a reversed direction when the reversing monitoring means has detected reversing.

2. The motor control apparatus according to claim 1, wherein the reversing preventing means causes current supply for A-phase for which current supply was effected immediately before detection of the reversing.

3. The motor control apparatus according to claim 1, wherein the reversing preventing means does not cause current supply for any phase when the reversing monitoring means has detected reversing.

4. The motor control apparatus according to claim 1, wherein the motor is a switched reluctance motor.

5. The motor control apparatus according to claim 1, wherein the encoder produces an A-phase signal and a B-phase signal that have a prescribed phase difference in synchronism with rotation of the rotor;

and

wherein in updating the count of the encoder by counting pulses of the A-phase signal and the B-phase signal in rotating the rotor, the control means determines a rotation direction of the rotor on the basis of order of occurrence of the pulses of the A-phase signal and the B-phase signal and increments or decrements the count of the encoder in accordance with the determined rotation direction of the rotor, and the control means selects a current supply phase in accordance with a resulting count of the encoder and the determined rotation direction of the rotor and effects current supply for the selected current supply phase.

6. The motor control apparatus according to claim 1, wherein the motor drives a position switching mechanism for switching between gear positions of an automatic transmission of a vehicle.

7. A motor control apparatus comprising:

an encoder for producing a pulse output signal in synchronism with rotation of a rotor of a motor; and

control means for rotating the rotor to a target position by detecting a rotation position of the rotor on the basis of a count of the output signal of the encoder and sequentially switching a current supply phase of the motor,

wherein the control means corrects A-phase lead of the current supply phase with respect to a rotation phase of the rotor in accordance with a rotation speed of the rotor.

8. The motor control apparatus according to claim 7, wherein when decreasing the rotation speed of the rotor is necessary, the control means corrects the phase lead of the current supply in a decreasing direction.

12. The motor control apparatus according to claim 7, wherein the motor is a switched reluctance motor.

13. The motor control apparatus according to claim 7, wherein the motor drives a position switching mechanism for switching between positions of an automatic transmission of the vehicle.

9. A motor control apparatus comprising:

an encoder for producing a pulse output signal in synchronism with rotation of a rotor of a motor; and

control means for rotating the rotor to a target position by detecting a rotation position of the rotor on the basis of a count of the output signal of the encoder and sequentially switching a current supply phase of the motor,

wherein the control means controls a rotation speed of the rotor by correcting A-phase lead of the current supply phase with respect to a rotation phase of the rotor and/or switching a current supply method.

10. A motor control apparatus comprising:

control means for rotating a rotor to a target position by sequentially switching a current supply phase of a motor,

wherein the control means executes a process of temporarily stopping and keeping the rotor at a drive end position by two-phase current supply at an end of driving.

11. A motor control apparatus comprising:

control means for rotating a rotor to a target position by sequentially switching a current supply phase of a motor,

wherein when the target position has been changed during driving and reversing a rotation direction of the rotor has become necessary, the control means executes a process of temporarily stopping and keeping the rotor at a reversing position by two-phase current supply.

14. A motor control apparatus comprising:

an encoder for producing a pulse output signal in synchronism with rotation of a rotor of a motor that rotates a control object;

pulse counting means for counting pulses of the output signal of the encoder;

control means for detecting a rotation position of the rotor on the basis of a count of the pulse counting means during a drive control on the motor and sequentially switching a current supply phase of the motor so as to rotate the rotor to a target position;

first current supply phase setting means for setting a current supply phase on the basis of the count of the pulse counting means in synchronism with output of a pulse of the output signal of the encoder during the drive control on the motor; and

second current supply phase setting means for setting a current supply phase on the basis of the count of the pulse counting means in a prescribed cycle until the rotor reaches the target position,

wherein every time the first or second current supply phase setting means sets a current supply phase, the control means energizes a winding of the current supply phase thus set.

15. The motor control apparatus according to claim 14, wherein the encoder produces an A-phase signal and a B-phase signal that have a prescribed phase difference in synchronism with rotation of the rotor,

the pulse counting means counts edges of the A-phase signal and the B-phase signal by edge interruption processing on the A-phase signal and the B-phase signal, and

the first current supply phase setting means sets a current supply phase by edge interruption processing on the A-phase signal and the B-phase signal.

16. The motor control apparatus according to claim 14, wherein the second current supply phase setting means sets a current supply phase in the prescribe cycle from a start of the drive control until the rotor reaches the target position.

17. The motor control apparatus according to claim 14, wherein the second current supply phase setting means sets a current supply phase in the prescribe cycle until the rotor reaches the target position in a period in which a rotation speed of the rotor is lower than or equal to a prescribed value.

18. The motor control apparatus according to claim 14, wherein the motor is a switched reluctance motor.

19. The motor control apparatus according to claim 14, wherein the motor drives a position switching mechanism for switching between positions of an automatic transmission of a vehicle.