CONTROL APPARATUS FOR VIBRATION-TYPE ACTUATOR, METHOD OF CONTROLLING VIBRATION-TYPE ACTUATOR, DRIVING APPARATUS, IMAGE PICKUP APPARATUS, AND AUTOMATIC STAGE

• US 20170017058A1
• Filed: 07/11/2016
• Published: 01/19/2017
• Est. Priority Date: 07/14/2015
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sumioka, Jun
• Granted Patent: US 10,775,583 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 21/26 Stages; Adjusting means therefor
• CPC Class Codes: G02B 27/646 compensating for small deviations, e.g. due to vibration or shake movement of one or more optical elements for control of motion blur in cameras, projectors or printers G03B2205/0007; image stabilisation in cameras peculiar to the presence or use of an electronic image sensor H04N23/68
• CPC Class Codes: G02B 7/09 adapted for automatic focusing or varying magnification
• CPC Class Codes: G03B 2205/0007 Movement of one or more optical elements for control of motion blur imaging systems in general using optical elements for stabilisation of the position of the image G02B27/64
• CPC Class Codes: G03B 2205/0046 Movement of one or more optical elements for zooming for optical zoom lenses in general G02B7/10
• CPC Class Codes: G03B 2205/0061 using piezoelectric actuators
• CPC Class Codes: G03B 3/10 Power-operated focusing
• CPC Class Codes: G03B 5/00 Adjustment of optical system relative to image or object surface other than for focusing
• CPC Class Codes: H02N 2/0015 using only bending modes
• CPC Class Codes: H02N 2/103 by pressing one or more vibrators against the rotor
• CPC Class Codes: H02N 2/142 Small signal circuits; Means for controlling position or derived quantities, e.g. speed, torque, starting, stopping, reversing

Abstract

A value obtained by adding an output of a speed feedforward calculation unit that uses a speed calculated from a change over time in an instruction value to a stage downstream from a feedback calculation unit that uses a positional deviation is used as a control amount, and at least one of an elliptic ratio of elliptical motion and a driving direction is controlled.

Claims

1. A control apparatus for a vibration-type actuator, the control apparatus comprising:

a control unit configured to generate a signal containing information for controlling a vibrator by adding a feedback amount that is obtained through at least one of integration processing and differentiation processing on the basis of a difference between a relative position of the vibrator and a driven member and an instruction value pertaining to the relative position and a speed feedforward amount that is obtained from a change over time in the instruction value,

wherein the relative position of the vibrator and the driven member is changed by driving the vibrator.

2. The control apparatus for a vibration-type actuator according to claim 1,

wherein the vibrator is configured such that the relative position is changed by elliptical motion generated in a driving unit of the vibrator by applying an alternating current signal to the vibrator.

3. The control apparatus for a vibration-type actuator according to claim 1,

wherein the control unit includes:

a feedback calculation unit configured to obtain the feedback amount;

a speed feedforward calculation unit configured to obtain the speed feedforward amount; and

an adder configured to output a control amount by adding the feedback amount and the speed feedforward amount.

4. The control apparatus for a vibration-type actuator according to claim 3,

wherein the speed feedforward calculation unit includes:

a speed calculation unit configured to take a time derivative of the instruction value and output the time derivative; and

a multiplier configured to multiply an output of the speed calculation unit by a speed feedforward gain.

5. The control apparatus for a vibration-type actuator according to claim 3,

wherein Gv and Gd satisfy a following formula:

Gv≦

Gd,

wherein the Gv represents a speed feedforward gain of the speed feedforward calculation unit and the Gd represents a derivative gain of the feedback calculation unit.

6. The control apparatus for a vibration-type actuator according to claim 3,

wherein the feedback calculation unit further includes an acceleration calculation unit constituted by a second derivative term.

7. The control apparatus for a vibration-type actuator according to claim 3,

wherein the control unit includes a control parameter generation unit configured to generate a control parameter on the basis of the control amount.

8. The control apparatus for a vibration-type actuator according to claim 7,

wherein the control parameter is at least one of a frequency and a phase.

9. The control apparatus for a vibration-type actuator according to claim 3,

wherein a driving unit configured to generate an alternating current signal to be applied to the vibrator on the basis of an output of the control unit is provided.

10. The control apparatus for a vibration-type actuator according to claim 9,

wherein the driving unit includes an alternating current signal generation unit configured to generate an alternating current signal that is one of a phase and a frequency set on the basis of the control amount.

11. A driving apparatus, comprising:

the control apparatus for a vibration-type actuator according to claim 1; and

the vibration-type actuator.

12. A replacement lens, comprising:

a lens; and

the control apparatus for a vibration-type actuator according to claim 1 configured to drive the lens by driving the driven member.

13. An image pickup apparatus, comprising:

an image pickup element;

a lens; and

the control apparatus for a vibration-type actuator according to claim 1 configured to drive the lens by driving the driven member.

14. An automatic stage, comprising:

a stage; and

the control apparatus for a vibration-type actuator according to claim 1 configured to drive the stage by driving the driven member.

15. A control apparatus for a vibration-type actuator, the control apparatus comprising:

a control unit configured to generate a signal containing information for controlling at least one of an elliptic ratio of elliptical motion generated in a driving unit of a vibrator and a driving direction of the vibrator by adding a feedback amount that is based on a difference between a relative position of the vibrator and a driven member and an instruction value pertaining to the relative position and a speed feedforward amount that is obtained from a change over time in the instruction value,

wherein the relative position of the vibrator and the driven member can be changed by driving the vibrator.

16. The control apparatus for a vibration-type actuator according to claim 15,

wherein the feedback amount is generated by a feedback calculation unit configured to carry out at least one of integration processing and differentiation processing.

17. The control apparatus for a vibration-type actuator according to claim 15,

wherein the control unit includes;

a feedback calculation unit configured to obtain the feedback amount;

a speed feedforward calculation unit configured to obtain the speed feedforward amount; and

an adder configured to output a control amount by adding the feedback amount and the speed feedforward amount.

18. The control apparatus for a vibration-type actuator according to claim 17,

wherein the speed feedforward calculation unit includes:

a speed calculation unit configured to take a time derivative of the instruction value and output the time derivative; and

a multiplier configured to multiply an output of the speed calculation unit by a speed feedforward gain.

19. The control apparatus for a vibration-type actuator according to claim 17,

wherein Gv and Gd satisfy a following formula:

Gv≦

Gd,

wherein the Gv represents a speed feedforward gain of the speed feedforward calculation unit and the Gd represents a derivative gain of the feedback calculation unit.

20. The control apparatus for a vibration-type actuator according to claim 17,

wherein the feedback calculation unit further includes an acceleration calculation unit constituted by a second derivative term.

21. The control apparatus for a vibration-type actuator according to claim 17,

wherein the control unit includes a control parameter generation unit configured to generate a control parameter on the basis of the control amount.

22. The control apparatus for a vibration-type actuator according to claim 21,

wherein the control parameter is at least one of a frequency and a phase.

23. The control apparatus for a vibration-type actuator according to claim 17,

wherein a driving unit configured to generate an alternating current signal to be applied to the vibrator on the basis of an output of the control unit is provided.

24. The control apparatus for a vibration-type actuator according to claim 23,

wherein the driving unit includes an alternating current signal generation unit configured to generate an alternating current signal that is one of a phase and a frequency set on the basis of the control amount.

25. A driving apparatus, comprising:

the control apparatus for a vibration-type actuator according to claim 15; and

the vibration-type actuator.

26. A replacement lens, comprising:

a lens; and

the control apparatus for a vibration-type actuator according to claim 15 configured to drive the lens by driving the driven member.

27. An image pickup apparatus, comprising:

an image pickup element;

a lens; and

the control apparatus for a vibration-type actuator according to claim 15 configured to drive the lens by driving the driven member.

28. An automatic stage, comprising:

a stage; and

the control apparatus for a vibration-type actuator according to claim 15 configured to drive the stage by driving the driven member.

29. A method of controlling a vibration-type actuator in which a vibrator is driven so as to change a relative position of the vibrator and a driven member, the method comprising the steps of:

obtaining a feedback amount obtained through at least one of integration processing and differentiation processing on the basis of a difference between the relative position of the vibrator and the driven member and an instruction value pertaining to the relative position;

obtaining a speed feedforward amount from a change over time in the instruction value; and

generating a signal containing information for controlling the vibrator by adding the feedback amount and the speed feedforward amount.