Motor control apparatus, motor control method, hard disk drive testing apparatus, and storage device manufacturing method

Abstract

A motor control apparatus that drives and controls a holeless DC motor is disclosed. The motor control apparatus includes a breaking part configured to break the DC holeless motor, a detection part configured to detect whether the DC holeless motor is in a near halt rotation state, and a forced stopping part configured to forcibly stop rotation of the DC holeless motor when the detection part detects that the DC holeless motor is in the near halt rotation state.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a functional configuration of a motor control apparatus according to an embodiment of the present invention;

FIG. 2 is a diagram showing a configuration of a three-phase-six-pole DC motor;

FIG. 3 is a diagram illustrating excitation patterns of the DC motor;

FIG. 4 is a block diagram showing a hardware configuration of the motor control apparatus;

FIG. 5 is a perspective view of a hard disk drive testing apparatus according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating a short breaking mode that is realized by the motor control apparatus;

FIG. 7 is a graph showing a relationship between the motor rotation number and the rotation mode upon executing a breaking process;

FIG. 8 is a flowchart showing the basic process steps of the breaking process;

FIG. 9 is a timing chart showing relative timings of a detection timing signal, a phase signal, excitation switching signals, and the breaking control process in the short breaking mode;

FIG. 10 is a timing chart illustrating timings of the excitation switching signals before reaching the time for switching from a reverse torque mode to a forced stopping mode; and

FIG. 11 is a timing chart illustrating timings of the excitation switching signals at a point where the forced stopping mode breaking process is started.

Claims

1. A motor control apparatus that drives and controls a holeless DC motor, the motor control apparatus comprising: a breaking part configured to break the DC holeless motor;a detection part configured to detect whether the DC holeless motor is in a near halt rotation state; anda forced stopping part configured to forcibly stop rotation of the DC holeless motor when the detection part detects that the DC holeless motor is in the near halt rotation state.

2. A motor control apparatus that controls a DC motor including a plurality of phase coils, the motor control apparatus comprising: a first controller configured to short-circuit the plurality of phase coils during a first period;a second controller configured to supply a current to the plurality of phase coils and induce generation of a reverse direction torque during a second period following the first period; anda third controller configured to apply a predetermined exciting current to at least one of said phase coils for a predetermined time, during a third period following the second period, thereby stopping rotation of the DC motor.

3. The motor control apparatus as claimed in 1, wherein: the third controller is configured to apply the predetermined exciting current to two of the phase coils.

4. A motor control apparatus that drives and controls a DC holeless motor including a U-phase coil, a V-phase coil, and a W-phase coil, the motor control apparatus comprising: a short breaking part configured to apply short breaking on the DC holeless motor when a rotation stop command is input;a first detection part configured to detect a reverse torque supplying start time;a reverse torque generating part configured to supply a current to the U-phase coil, the V-phase coil, and the W-phase coil and induce generation of a reverse direction torque when the first detection part detects the reverse torque supplying start time;a second detection part configured to detect whether the DC holeless motor is in a near halt rotation state; anda forced stopping part configured to forcibly stop rotation of the DC holeless motor when the second detection part detects that the DC holeless motor is in the near halt rotation state.

5. The motor control apparatus as claimed in claim 4, wherein the first detection part is configured to detect the reverse torque supplying start time based on a time period elapsed from a time the rotation stop command is input.

6. The motor control apparatus as claimed in claim 4, wherein the first detection part is configured to detect a time when the rotation of the DC holeless motor equals to 50% of a steady-state rotation of the DC holeless motor as the reverse torque supplying start time.

7. The motor control apparatus as claimed in claim 4, wherein a short breaking process realized by the short breaking part, a reverse torque generating process realized by the reverse torque generating part, and an inertial rotation process involving stopping the current supply to the U-phase coil, the V-phase coil, and the W-phase coil are alternatingly performed during a time after the reverse torque supplying start time is detected and before the near halt rotation state of the DC holeless motor is detected.

8. The motor control apparatus as claimed in claim 4, wherein the forced stopping part is configured to stop the rotation of the DC holeless motor by forcibly exciting two of the U-phase coil, the V-phase coil, and the W-phase coil.

9. The motor control apparatus as claimed in claim 4, wherein the second detection part is configured to detect that the DC holeless motor is in the near halt rotation state when a time interval of a current switching signal used for selectively supplying the current to the U-phase coil, the V-phase coil, and the W-phase coil becomes greater than a predetermined time interval.

10. A motor control method for driving and controlling a DC motor including a first phase coil, a second phase coil and a third phase coil, the motor control method comprising the steps of: short-circuiting the first phase coil, the second phase coil, and the third phase coil for a first period;supplying a current to the first phase coil, the second phase coil, and the third phase coil, and inducing generation of a reverse direction torque for a second period after the first period is ended; andapplying a predetermined exciting current to as least one of said first, second, and third phase coils for a third period after the second period is ended.

11. The motor control method as claimed in 10, wherein: the step of applying the predetermined exciting current involves exciting two of the first phase coil, the second phase coil, and the third phase coil.

12. A motor control method for driving and controlling a DC holeless motor including a U-phase coil, a V-phase coil, and a W-phase coil, the motor control method comprising the steps of: applying short breaking on the DC holeless motor when a rotation stop command is input;detecting a reverse torque supplying start time;supplying a current to the U-phase coil, the V-phase coil, and the W-phase coil and inducing generation of a reverse direction torque when the reverse torque supplying start time is detected;detecting whether the DC holeless motor is in a near halt rotation state; andforcibly stopping rotation of the DC holeless motor when the DC holeless motor is detected to be in the near halt rotation state.

13. The motor control method as claimed in claim 12, wherein the step of detecting the reverse torque supplying start time involves detecting the reverse torque supplying start time based on a time period elapsed from a time the rotation stop command is input.

14. The motor control method as claimed in claim 12, wherein the step of detecting the reverse torque supplying start time involves determining a time when the rotation of the DC holeless motor equals to 50% of a steady-state rotation of the DC holeless motor as the reverse torque supplying start time.

15. The motor control method as claimed in claim 12, wherein a short breaking process, a reverse torque generating process, and an inertial rotation process involving stopping the current supply to the U-phase coil, the V-phase coil, and the W-phase coil are alternatingly performed during a time after the reverse torque supplying start time is detected and before the near halt rotation state of the DC holeless motor is detected.

16. The motor control method as claimed in claim 12, wherein the step of forcibly stopping the rotation of the DC holeless motor involves forcibly exciting two of the U-phase coil, the V-phase coil, and the W-phase coil.

17. The motor control method as claimed in claim 12, wherein the step of detecting whether the DC holeless motor is in the near halt rotation state involves determining that the DC holeless motor is in the near halt rotation state when an time interval of a current switching signal used for selectively supplying the current to the U-phase coil, the V-phase coil, and the W-phase coil becomes greater than a predetermined time interval.

18. A hard disk drive testing apparatus comprising: a DC holeless motor configured to rotate a hard disk upon testing the hard disk; anda motor control apparatus configured to drive and control the DC holeless motor;wherein the motor control apparatus includes a breaking part configured to break the DC holeless motor;a detection part configured to detect whether the DC holeless motor is in a near halt rotation state; anda forced stopping part configured to forcibly stop rotation of the DC holeless motor when the detection part detects that the DC holeless motor is in the near halt rotation state.

19. A hard disk drive testing apparatus comprising: a DC holeless motor including a U-phase coil, a V-phase coil, a W-phase coil, which DC holeless motor is configured to rotate a hard disk upon testing the hard disk; anda motor control apparatus configured to drive and control the DC holeless motor;wherein the motor control apparatus includes a short breaking part configured to apply short breaking on the DC holeless motor when a rotation stop command is input;a first detection part configured to detect a reverse torque supplying start time;a reverse torque generating part configured to supply a current to the U-phase coil, the V-phase coil, and the W-phase coil and induce generation of a reverse direction torque when the first detection part detects the reverse torque supplying start time;a second detection part configured to detect whether the DC holeless motor is in a near halt rotation state; anda forced stopping part configured to forcibly stop rotation of the DC holeless motor when the second detection part detects that the DC holeless motor is in the near halt rotation state.

20. A method for manufacturing a storage device including a recording medium and a motor that rotates the recording medium, the method comprising the steps of: rotating the motor;performing a short breaking process on the motor;exciting the motor and inducing the motor to generate a reverse torque when a rotation speed of the motor reaches a value that is less than or equal to a first predetermined value;forcibly stopping rotation of the motor when the rotation speed of the motor reaches a value that is less than or equal to a second predetermined value which second predetermined value is less than the first predetermine value; andperforming one or more processes on the storage device after the motor is stopped.

21. A motor drive control method for driving and controlling a motor including plural excitation phases, the method comprising the steps of: short-circuiting the excitation phases while the motor is rotating;exciting the motor and inducing the motor to generate a reverse rotation direction torque when a rotation number of the motor reaches a first predetermined value; andperforming forced excitation for a predetermined time period in accordance with a predetermined excitation pattern when the rotation number of the motor reaches a second predetermined value which second predetermined value is less than the first predetermined value.