JP2012055111A - Control device of vibration type driving device and output characteristic detection method of vibration type driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control apparatus of a vibration type driving device capable of detecting a variation in output characteristics due to a manufacturing process and shape of a vibrator in the state where the vibrator is mounted as the vibration type driving device.SOLUTION: Under a control by control means, an alternating voltage which makes a driver cause an elliptic movement by exciting a vibration in a first vibration mode which makes the driver displace in a direction vertical to a contact surface with a body to be driven and by exciting a vibration in a second vibration mode which makes the driver displace in a direction parallel to the contact surface with the body to be driven, is applied to a detection object vibrator, among a plurality of vibrators, whose output characteristics are detected, by driving signal generation means, and on the other hand, only an alternating voltage which excites the vibration in the first vibration mode is applied to a vibrator other than the detection object vibrator by the driving signal generation means, and the output characteristic of the detection object vibrator is detected by output characteristic detection means.

Description

  The present invention relates to a control device for a vibration type drive device and an output characteristic detection method for the vibration type drive device, and more particularly to a technique for detecting output characteristics of the vibration type drive device.

Conventionally, various proposals (for example, Patent Document 1) have been made on a vibration type driving device that generates an elliptical motion at a predetermined mass point and drives a driven body. As a basic configuration of such a vibration type driving device, for example, a configuration as shown in FIG. 13A is known.
FIG. 13A is an external perspective view showing an example of a basic configuration of the vibration type driving device in the conventional example.
As shown in FIG. 13 (a), the vibrator of the vibration type driving device includes an elastic body 4 made of a metal material formed in a rectangular plate shape, and a piezoelectric element (electrical element) is provided on the back surface of the elastic body 4. Mechanical energy conversion element) 5 is joined. A plurality of protrusions 6 are provided at predetermined positions on the upper surface of the elastic body 4.
According to this configuration, by applying an AC voltage to the piezoelectric element 5, a secondary bending vibration in the long side direction of the elastic body 4 and a primary bending vibration in the short side direction of the elastic body 4 are simultaneously generated. Then, elliptical motion is excited in the protrusion 6.
The driven body 7 can be linearly driven by the elliptical motion of the protruding portion 6 by bringing the driven body 7 into pressure contact with the protruding portion 6. That is, the protrusion 6 acts as a drive unit for the vibrator.

FIG. 13B is a schematic diagram illustrating an example of a polarization region of the piezoelectric element 5 in the vibration type driving device illustrated in FIG.
FIGS. 14A and 14B are perspective views showing vibration modes of the elastic body 4 in the conventional example, and FIG. 15A is an ellipse excited on the protrusion 6 of the elastic body 4 in the conventional example. It is a figure for demonstrating exercise | movement.
The piezoelectric element 5 includes two electrodes A1 and A2 as shown in an example of a polarization region of the piezoelectric element 5 in the vibration type driving device shown in FIG.
By applying in-phase AC voltages V1 and V2 to the two electrodes A1 and A2, primary bending vibration having two nodes extending in a direction parallel to the long side direction in the rectangular elastic body 4 is generated. Excited.
This is the first vibration mode shown in FIG.
Further, by applying AC voltages V1 and V2 having opposite phases to the two electrodes A1 and A2, a secondary bending vibration having three nodes extending in a direction parallel to the short side direction of the rectangular elastic body 4 is obtained. Excited. This is the second vibration mode shown in FIG.
Then, when the elliptical motion is excited in the protrusion 6 by the combination of the first vibration mode and the second vibration mode, and the driven body is brought into pressure contact with the protrusion 6 at this time, the driven body is linearly moved. Can be driven to.
Here, according to the first vibration mode shown in FIG. 14A, the protrusion 6 has a first amplitude (hereinafter, Z-axis) that is displaced in a direction perpendicular to the contact surface that is in pressure contact with the driven body. Is also excited).
Further, the second vibration mode shown in FIG. 14B excites a second amplitude (hereinafter, also referred to as an X-axis amplitude) that is displaced in a direction parallel to the contact surface in the protrusion 6.

By combining the two amplitude modes of the first vibration mode and the second vibration mode, elliptical motion can be excited in the predetermined protrusion 6 as shown in FIG. The ratio of the magnitude of the X-axis amplitude affects the ellipticity ratio of the elliptical motion.
FIG. 15B is a graph for explaining the amplitudes of the first vibration mode and the second vibration mode when the phase difference between the two-phase voltages V1 and V2 is changed from −180 degrees to 180 degrees. is there.
The first vibration mode and the second vibration mode when the phase difference between the two-phase AC voltages V1 and V2 applied to the two electrodes A1 and A2 in the polarized piezoelectric element 5 is changed from −180 degrees to 180 degrees. The amplitude of the vibration mode is as indicated by P1 and P2 in FIG.
In the figure, the horizontal axis indicates the phase difference, and the vertical axis indicates the amplitude of the first vibration mode and the second vibration mode.
The elliptical motion is excited in the protrusion 6 by the combination of the first vibration mode and the second vibration mode, and the elliptical motion that the predetermined protrusion 6 is excited by changing the phase difference between the applied AC voltages V1 and V2. The ellipse ratio can be adjusted. An elliptical shape corresponding to the phase difference on the horizontal axis is shown in the lower part of FIG.
Then, by switching the sign of the phase difference between the AC voltages V1 and V2, the driving direction of the vibration type driving device that drives linearly can be switched.
Furthermore, the phase difference is continuously switched from an arbitrary value including a positive / negative sign (for example, the phase difference is continuously changed from 90 degrees to −90 degrees including a positive / negative sign) to thereby change the driving direction. It becomes possible to change the speed continuously.
In addition, the speed can be increased by bringing the frequency of the alternating voltage applied to the piezoelectric element closer to the resonance frequency, and the speed can be decreased by moving the frequency of the applied alternating voltage away from the resonance frequency. Known.
By using a plurality of vibrators having such a configuration and obtaining a thrust by the above elliptical motion, it becomes possible to relatively drive one driven body.

JP 2004-320846 A

However, when one driven body is relatively driven by a plurality of vibrators as described above, there are the following problems.
That is, when one driven body is relatively driven by a plurality of vibrators, if the output characteristics of the vibrators vary, the efficiency is lowered during the relative driving due to the deviation of the output characteristics.
Therefore, it is necessary to adjust the output characteristics of each vibrator. In order to detect the output characteristics of each vibrator when adjusting the output characteristics, it is necessary to detect the output characteristics independently before incorporating the vibrator into the apparatus.
For this reason, extra work such as disassembly and assembly by attaching to the output characteristic measuring device for detecting the output characteristic is required.

  In view of the above problems, the present invention provides a vibration-type driving device that can detect variations in output characteristics caused by the manufacturing process and shape of the vibrator while the vibrator is attached as the vibration-type driving device. It is an object of the present invention to provide an output characteristic detection method for a control device and a vibration type drive device.

A control device for a vibration-type driving device according to the present invention includes a plurality of vibrators having an electro-mechanical energy conversion element and a driving unit, and a driven body that contacts the driving units of the plurality of vibrators. A control device for a vibration-type driving device that causes an elliptical motion to occur in the driving units of the plurality of vibrators by applying an AC voltage to the mechanical energy conversion element, and relatively moves the driven body in contact with the driving units; And
Drive signal generating means for applying the AC voltage to each vibrator of the plurality of vibrators;
A drive frequency and a phase difference of an alternating voltage applied to each vibrator in the plurality of vibrators are determined, and the determined drive frequency and the phase difference are output to the drive signal generation means to output the drive signal generation means. Control means for controlling;
Output characteristic detection means for detecting output characteristics of each vibrator in the plurality of vibrators by comparing the drive speed of the driven body and the drive frequency in the drive signal generation means;
Under the control of the control means,
A vibration in a first vibration mode that displaces the drive unit in a direction perpendicular to a contact surface with the driven body with respect to a detection target vibrator that detects output characteristics of the plurality of vibrators; The drive signal generating means generates an AC voltage that causes elliptical motion in the drive unit by exciting the vibration in the second vibration mode that displaces the drive unit in a direction parallel to the contact surface with the driven body. While applying
Only the AC voltage that excites the vibration in the first vibration mode is applied to the vibrator other than the vibrator to be detected by the drive signal generation unit,
The output characteristic detecting means detects the output characteristic of the transducer to be detected.
Further, the control device of the control device of the vibration type drive device of the present invention includes a plurality of vibrators having an electro-mechanical energy conversion element and a drive unit, a driven body that contacts the drive units of the plurality of vibrators, With
A control device for a vibration type driving device that causes an elliptical motion to occur in the driving portions of the plurality of vibrators by applying an alternating voltage to the electro-mechanical energy conversion element, and relatively moves the driven body in contact with the driving portions. Because
Drive signal generating means for applying the AC voltage to each vibrator of the plurality of vibrators;
A drive frequency and a phase difference of an alternating voltage applied to each vibrator in the plurality of vibrators are determined, and the determined drive frequency and the phase difference are output to the drive signal generation means to output the drive signal generation means. Control means for controlling;
Output characteristic detecting means for detecting the relationship between the output characteristics of each vibrator in the plurality of vibrators,
The plurality of vibrators include at least two vibrators including a first vibrator and a second vibrator, and are controlled by the control unit.
With respect to the first vibrator, vibration in a first vibration mode for displacing the drive unit in a direction perpendicular to the contact surface with the driven body, and in a direction parallel to the contact surface with the driven body While applying an AC voltage that causes an elliptical motion in the drive unit by exciting the vibration of the second vibration mode that displaces the drive unit,
An AC voltage that generates a driving force in a direction that cancels the driving force due to the elliptical motion of the driving unit of the first vibrator is applied to the second vibrator by the driving signal generation unit,
The output characteristic detecting means detects a relationship between the output characteristic of the first vibrator and the output characteristic of the second vibrator.
Further, the output characteristic detection method of the vibration type driving device of the present invention includes a plurality of vibrators each having an electro-mechanical energy conversion element and a driving unit, and a driven body that contacts the driving units of the plurality of vibrators. Prepared,
Output characteristics of a vibration-type driving device that causes an elliptical motion in the driving units of the plurality of vibrators by applying an AC voltage to the electro-mechanical energy conversion element, and relatively moves the driven body in contact with the driving units. A detection method,
A vibration in a first vibration mode that displaces the drive unit in a direction perpendicular to a contact surface with the driven body with respect to a detection target vibrator that detects output characteristics of the plurality of vibrators; While applying an alternating voltage that causes elliptical motion in the drive unit by exciting the vibration of the second vibration mode that displaces the drive unit in a direction parallel to the contact surface with the driven body,
An alternating voltage that excites vibration in only the first vibration mode is applied to a vibrator other than the vibrator to be detected,
An output characteristic of the transducer to be detected is detected.
Further, the output characteristic detection method of the vibration type driving device of the present invention includes a plurality of vibrators each having an electro-mechanical energy conversion element and a driving unit, and a driven body that contacts the driving units of the plurality of vibrators. Prepared,
Output characteristics of a vibration-type driving device that causes an elliptical motion in the driving units of the plurality of vibrators by applying an AC voltage to the electro-mechanical energy conversion element, and relatively moves the driven body in contact with the driving units. A detection method,
The plurality of vibrators include at least two vibrators including a first vibrator and a second vibrator,
With respect to the first vibrator, vibration in a first vibration mode for displacing the drive unit in a direction perpendicular to the contact surface with the driven body, and in a direction parallel to the contact surface with the driven body While applying an alternating voltage that causes elliptical motion in the drive unit by exciting vibrations in a second vibration mode that displaces the drive unit,
An alternating voltage that generates a driving force in a direction that cancels the driving force due to the elliptical motion of the driving unit of the first vibrator is applied to the second vibrator,
A relationship between output characteristics of the first vibrator and output characteristics of the second vibrator is detected.

  According to the present invention, it is possible to detect the variation in the output characteristics of the vibrator in a state where the vibrator is attached as the vibration type driving device, and the output characteristic of the vibration type driving device. A detection method can be realized.

It is an external appearance perspective view explaining the structure of the vibration type drive device which concerns on 1st Embodiment. It is a block diagram explaining the control operation of the vibration type drive device concerning a 1st embodiment. 6 is a graph showing the relationship between the drive frequency and the drive speed of the vibrator according to the first embodiment. It is a figure for demonstrating the driving force and frictional force which concern on 1st Embodiment. It is a flowchart explaining the detection method of the output characteristic in the vibration type drive device which concerns on 1st Embodiment. It is a graph which shows the relationship between the drive frequency and drive speed in each vibrator | oscillator of the vibration type drive device which concerns on 1st Embodiment. It is a graph which shows the relationship between the drive speed and drive frequency in each vibrator | oscillator of the vibration type drive device which concerns on 1st Embodiment. It is a figure explaining operation | movement of another form of the vibration type drive device which concerns on 1st Embodiment. It is a figure explaining the detection method of the output characteristic in the vibration type drive device concerning a 2nd embodiment. It is a flowchart explaining the output characteristic detection method of the vibration type drive device which concerns on 2nd Embodiment. It is a graph which shows the relationship of the drive frequency of the vibrator | oscillator 8a and the vibrator | oscillator 8b of the vibration type drive device which concerns on 2nd Embodiment. It is a block diagram of the vibration type drive device which concerns on 3rd Embodiment. It is a figure for demonstrating a prior art example, (a) is an external appearance perspective view which shows an example of the fundamental structure of a vibration type drive device. (B) is a schematic diagram showing an example of a polarization region of a piezoelectric element in the vibration type driving device shown in (a). It is a perspective view which shows the vibration mode of the elastic body in a prior art example. It is a figure for demonstrating a prior art example, (a) is a figure for demonstrating the elliptical motion excited to the projection part of an elastic body. (B) is a graph for explaining the amplitudes of the first vibration mode and the second vibration mode. (C) is a graph showing the relationship between the frequency and speed of the vibrator.

Hereinafter, a control device for a vibration type driving device and an output characteristic detection method for the vibration type driving device according to an embodiment of the present invention will be described with reference to the drawings.
[First Embodiment]
The configuration of the vibration type driving device (vibration type actuator) in the first embodiment of the present invention will be described with reference to FIG.
The vibration type driving apparatus of the present embodiment has a configuration in which one driven body is relatively driven by two vibrators, and the two vibrators can generate a double thrust.
As shown in FIG. 1, the vibrator 8a of the vibration type drive device of this embodiment includes an elastic body 4a made of a metal material formed in a rectangular plate shape, and a piezoelectric element (electrical element) is provided on the back surface of the elastic body 4a. -Mechanical energy conversion element) 5a is joined.
Two protrusions 6a that act as drive units are provided at predetermined positions on the upper surface of the elastic body 4a. The vibrator shown in FIG. 1 causes an elliptical motion in the protrusion and drives the driven body. Similarly, in the vibrator 8b, a piezoelectric element 5b is bonded to the elastic body 4b, and two protrusions 6b are provided at predetermined positions of the elastic body 4b.
The piezoelectric elements 5a and 5b shown in FIG. 1 are provided with two groups of electrodes A1 and A2 shown in FIG. 13B, and are polarized in the paper direction of FIG. 13B.
The vibrator having this configuration can change the elliptical ratio of the elliptical motion excited in the protrusions 6a and 6b shown in FIG. 1 by changing the phase difference of the applied AC voltage.

As shown in FIG. 15C, the vibrator shown in FIG. 1 can be increased in speed by bringing the drive frequency of the AC voltage applied to the piezoelectric element of the vibrator close to the resonance frequency. Further, the speed can be reduced by keeping the frequency of the applied AC voltage away from the resonance frequency.
Further, the resonance frequency is a peak of speed, and the driving speed is gently decreased on the higher frequency side than the resonance frequency, and the driving speed is rapidly decreased on the lower frequency side.
In addition, the moving speed of the driven body can be increased by increasing the amplitude (second amplitude) that is displaced (excited) in the direction parallel to the contact surface that excites the protrusions 6a and 6b.
In addition, the moving speed of the driven body is stabilized by reducing the amplitude displaced in the direction parallel to the contact surface and maintaining the amplitude (first amplitude) displaced (excited) in the direction perpendicular to the contact surface to some extent. Can be slow.
Further, the vibration of the first vibration mode shown in FIG. 14A (the mode in which the first amplitude that is displaced in the direction perpendicular to the contact surface where the protrusion 6 is in pressure contact with the driven body is excited). By switching the phase difference between the second vibration mode shown in FIG. 14B (vibration in a mode in which the protrusion 6 is excited with a second amplitude displaced in a direction parallel to the contact surface). The driving direction of the vibration type driving device can be switched.
Further, when the phase difference of the AC voltage applied to the electrodes V1 and V2 of the piezoelectric element 5 shown in FIG. 13B is changed from −180 degrees to 180 degrees, the predetermined protrusions 6a and 6b are excited. The ellipticity ratio of the elliptical motion can be adjusted.
An elliptical shape corresponding to the phase difference on the horizontal axis is shown in the lower part of FIG. By continuously changing the phase difference from 90 degrees to -90 degrees including positive and negative signs, the driving direction and speed can be continuously changed.
With the above configuration, the driven body (slider) 3 can be driven by exciting the vibrators 8a and 8b in FIG.

Next, the control device and control operation of the vibration type driving device in the present embodiment will be described with reference to the block diagram of FIG.
FIG. 2 is a block diagram illustrating a control device of the vibration type driving device shown in FIG.
The vibration type driving device (vibration type actuator) 10 includes a vibrator 8 a, a vibrator 8 b, and a driven body 3.
The driven body 3 is driven by an elliptical motion that excites the protrusions of the vibrator.
The position detection means 14 detects the position of the driven body 3, and is constituted by, for example, a linear scale or an encoder.
A control calculation means 18 is connected to the output side of the position detection means 14. The control calculation means 18 compares the detection position of the position detection means with a target value for positioning (not shown) to perform control calculation, and determines the drive frequency and phase difference of each vibrator of the vibration type driving device.
Drive signal generation means 11 and drive signal generation means 12 are connected to the output side of the control calculation means 18.
The drive signal generating means is composed of a pulse generator and a booster circuit, receives the output of the control arithmetic means 18 and generates an AC voltage that is actually applied to the piezoelectric element 5 of the vibrator.
A speed detection means 15 is connected to the output side of the position detection means 14 and detects the speed of the driven body 3 by differential calculation of the detection position.
An output characteristic detection means 16 is connected to the output side of the speed detection means 15.
Information on drive frequency and phase difference generated by the drive signal generating means is connected to the input side of the output characteristic detecting means 16.
And it is comprised so that an output characteristic can be detected by comparing the drive speed of the to-be-driven body 3 detected by the speed detection means 15 with the drive frequency by a drive signal generation means by the method mentioned later. .
The output characteristic adjustment unit 17 calculates an adjustment value based on the output characteristic result of each vibrator detected by the output characteristic detection unit 16 and sets the adjustment value in the control calculation unit.

Next, output characteristics of the vibration type driving device in the present embodiment will be described with reference to FIG.
The above configuration makes it possible to output about twice as much thrust as when driven by a single vibrator. However, if the output characteristics of the two vibrators differ due to individual differences, the desired output You may not be able to get.
FIG. 3 shows the output characteristics of each vibrator of the vibration type driving device measured individually, and the relationship between the driving frequency and the driving speed of each vibrator is an output characteristic a and an output characteristic b.
When one driven body is relatively driven by the two vibrators having the output characteristics a and the output characteristics b shown in FIG. 3, if the same frequency is set for the two vibrators, the driving force is generated in the output characteristics a and the output characteristics b. Will be different.
For example, when the same frequency is set for the output characteristic a and the output characteristic b, a difference in the driving force corresponding to the difference between the output characteristic a and the output characteristic b is generated, so that an extra slip occurs in the contact portion, thereby causing the vibration type. The driving efficiency of the driving device is reduced.
The difference between the output characteristics a and the output characteristics b of the vibrator shown in FIG. 3 is an individual variation caused by the manufacturing process and shape of the vibrator, and this individual difference is obtained when the vibrator is attached to the apparatus. Detecting is the problem that the present invention is to achieve.
Here, when detecting the characteristics of one of the two vibrators shown in FIG. 1, it is necessary that the other vibrator does not generate a driving force.
However, when an AC voltage is not applied to the vibrator 8b that does not generate a driving force, the driven body 3 and the protrusion 6b come into contact with each other by friction, and a frictional force is generated in the driven body 3 and the protrusion 6b.
When the frictional force is large, there is a possibility that the driven body 3 cannot be driven by the driving force of the vibrator that detects the characteristic.

FIG. 4 is a diagram for explaining the driving force and the frictional force according to this embodiment.
As shown in FIG. 4, a driven body 3 that is relatively driven by two vibrators is disposed.
The driven body 3 is a rectangular plate supported by a guide (not shown), and can be driven in the same direction as the direction of the driving force of the vibration type driving device.
The vibration in the second vibration mode that excites the second amplitude on the predetermined protrusion 6a of the vibrator 8a shown in FIG. 4 is increased.
Alternatively, the vibration in the first vibration mode for exciting the first amplitude in the protrusion 6a of the vibrator 8a and the vibration in the second vibration mode for exciting the second amplitude in the protrusion 6a are simultaneously excited.
Thereby, elliptical motion can be excited and a driving force can be generated in the direction of the driving force 41a.
The driving force of the vibrator 8a is indicated by the arrow of the driving force 41a shown in FIG. 4, and can be changed by the amplitude displaced in a direction parallel to the contact surface that excites the protrusion 6a of the vibrator 8a. The vibrator 8b has the same configuration.

When an AC voltage is not applied to the vibrator 8b shown in FIG. 4A, the driven body 3 and the protrusion 6b come into contact with each other by friction, so that a frictional force 41b is generated in the driven body 3 and the protrusion 6b. .
For example, when an AC voltage is not applied to the vibrator 8b and a driving force 41a is generated on the protrusion 6a of the vibrator 8a, a frictional force is generated between the protrusion 6b of the vibrator 8b and the driven body 3, When the frictional force is large, the driven body 3 cannot be driven by the driving force 41a.
Therefore, in order to avoid a state in which the apparatus cannot be driven by the frictional force of the vibrator that does not apply a driving force, the characteristics are detected in the driving state shown in FIG.
In the vibrator 8b shown in FIG. 4B, only the vibration in the first vibration mode can be excited by setting the phase difference of the AC voltage applied to the two electrodes to 0 °.
As a result, the frictional force generated in the vibrator 8b and the driven body 3 can be reduced as compared with the case where a frictional force is generated without applying an AC voltage to the vibrator 8b.

Next, the output characteristic detection method of the vibration type driving device in the present embodiment will be described with reference to the flowchart of FIG.
First, in STEP 1, a command for starting characteristic detection is issued and an output detection operation is started.
Next, in STEP 2, the output detection target is set to the vibrator 8a.
Next, in TEP3, the frequency applied to the output detection target transducer is set to a predetermined frequency upper limit value.
Here, the upper frequency limit is the maximum value of the frequency set as the applied voltage of the vibrator in actual control. The output detection operation of the present embodiment is performed by sweeping the driving frequency of the vibration type driving device from a high frequency to a low frequency.
Next, in STEP 4, the phase difference of the vibrator 8a is set to 90 degrees.
In STEP 4, the phase difference of the vibrator 8a that is the target of output detection is set to a phase difference of 90 degrees that can generate a sufficient driving force.
Next, in STEP 5, the drive frequency of the vibrator 8b that is not the output detection target is set close to the resonance frequency, and the phase difference is set to 0 degrees.
As described above, it is possible to excite only the first amplitude by setting the ellipticity of the elliptical motion excited by the predetermined protrusion 6b to the elliptical ratio corresponding to the phase difference of 0 degree shown in the lower part of FIG. it can.
Moreover, the first amplitude can be increased by setting the drive frequency of the vibrator 8b close to the resonance frequency. Compared with the case where the amplitude is small, the contact time between the driven body 3 and the protrusion 6b can be reduced, and the influence of the driven body 3 in the driving direction can be reduced.

In subsequent STEP 6, the speed of the driven body is detected. In STEP 1 to STEP 5 described above, the output of the vibrator 8a is detected at this point.
Next, in STEP 7, the speed detected in STEP 6 with respect to the frequency applied to the transducer 8a that is the output detection target is stored.
Next, in STEP 8, it is determined whether or not the frequency applied to the vibrator 8a that is the output detection target has reached a predetermined lower frequency limit.
Here, the lower frequency limit is the minimum value of the frequency set as the applied voltage of the vibrator in actual control. If the frequency lower limit has not been reached, proceed to STEP 9, and if it has reached, proceed to STEP 10.
In STEP 9, the frequency applied to the transducer 8a that is the output detection target is lowered.
In this output detection operation, the drive frequency of the vibration type motor is swept from a high frequency to a low frequency to detect the speed. Therefore, the frequency is lowered, and then the process proceeds to STEP 6 to repeat the above operation.
In STEP 10, it is determined whether the detection of the output characteristics of the vibration type driving device has been completed. If the detection of the output characteristics of the vibration type driving device has not been completed, the process proceeds to STEP 11, and if it has been completed, the process proceeds to STEP 12.
In STEP 11, the target whose output characteristics are detected is changed from the vibrator 8a to the vibrator 8b. Thereafter, the process proceeds to STEP 3 and the above operation is repeated. With this operation, the output characteristic of the vibrator 8b can be detected after the output characteristic of the vibrator 8a is detected.
In STPE 12, the output detection operation ends.
In the method of STEP1 to STEP12, after detecting the output characteristic of the vibrator 8a, the output characteristic of each vibrator as shown in FIG. 3 is detected by detecting the output characteristic of the vibrator 8b. be able to.

Next, the adjustment by the output characteristic adjusting means 17 shown in FIG. 2 in the control device of the vibration type driving device of the present embodiment will be described with reference to FIG.
FIG. 6 is an example of output characteristics of each vibrator according to the first embodiment. The output characteristic a indicates the output characteristic of the vibrator 8a, and the output characteristic b indicates the output characteristic of the vibrator 8b.
In the adjustment of the output characteristic, the adjustment by the output characteristic adjusting unit 17 is performed so that the output characteristic a and the output characteristic b coincide with each other.
The output characteristic difference, which is an adjustment value of the output characteristic adjustment operation, is obtained from the difference in drive frequency with respect to the drive speed in the output characteristic b and output characteristic a of each vibrator.
For example, when the adjustment value is derived from the output characteristics a and the output characteristics b as shown in FIG. 6, the driving frequency is obtained at an arbitrary driving speed v1 between the output characteristics a and the output characteristics b, and the difference (f1-f2) The output characteristic difference 1 is derived by calculating.
When an arbitrary frequency is set for the output characteristic b of the vibrator 8b, a frequency obtained by subtracting the output characteristic difference from the arbitrary frequency is applied to the vibrator 8a.
For example, when the pre-adjustment frequency f1 shown in FIG. 6 is set to the vibrator 8b, the output characteristic difference 1 is subtracted from f1 to derive f2. Then, by applying the derived f2 to the vibrator 8a, the characteristic difference between the output characteristic a and the output characteristic b can be matched. Here, the output characteristic difference may be obtained by calculating the driving frequency at all driving speeds, deriving the difference, and averaging processing.
Further, as shown in FIG. 7, the driving frequency may be obtained at each driving speed and stored in a memory (not shown), and the driving speed versus the driving frequency stored in the memory (not shown) may be used as the driving speed.
For example, when it is desired to drive at the drive speed v21 shown in FIG. 7, the drive frequency f21 stored in the memory (not shown) is applied to the vibrator 8a, and the drive frequency f22 stored in the memory (not shown) is applied to the vibrator 8b. By applying, the output characteristics may be adjusted.

According to the present embodiment, the output characteristic can be detected only for the transducer to be detected from which the output characteristic is detected among the plurality of transducers.
That is, in a vibration type driving device that relatively drives one driven body by a plurality of vibrators, a driving force is generated only for the protrusions of the vibrator to be detected that detects output characteristics of the plurality of vibrators. At the same time when the output characteristic is detected, only the vibration in the first vibration mode that excites the first amplitude in the protrusion is excited in the vibrator other than the vibrator to be detected.
Thereby, the output characteristic can be detected only for the transducer to be detected from which the output characteristic is detected among the plurality of transducers.
Then, by detecting each output characteristic and adjusting the output characteristic of each vibrator, it is possible to adjust and drive individual variations caused by the manufacturing process and shape of the vibration type driving device.
In the present embodiment, the transducer for detecting the output characteristics is configured as one. However, the present invention is not limited to such a configuration, and a plurality of transducers may be used as the detection target transducer. The synthesized output from the vibrator may be detected. Further, for example, as shown in FIG. 8, in addition to the first vibrator 8a and the second vibrator 8b, a vibration type driving device having three or more vibrators by the third vibrator 8c is configured. Then, the first vibrator 8a and the second vibrator 8b are excited with elliptical motion on the protrusions to give driving forces 81a and 81b, and the third vibrators other than the first vibrator 8a and the second vibrator 8b. The vibrator 8c can be configured to detect the output characteristics of the resultant force of the vibrators 8a and 8b to which the driving force is applied by exciting the vibration in the first vibration mode.

[Second Embodiment]
As a second embodiment, a configuration example based on a driving method and a characteristic detection operation at the time of characteristic detection in a form different from the first embodiment will be described.
In the driving apparatus using a plurality of vibrators in the first embodiment, a driving force is given to the vibrator for detecting characteristics, and the other vibrators are driven by exciting only the vibration in the first vibration mode. Detection was performed in a state where no force was generated. In the method of the first embodiment, the driven body 3 and the vibrator are relatively moved when detecting characteristics.
In the present embodiment, an example is shown in which the characteristics of each vibrator can be detected even in a state where the driven body and the vibrator do not move relatively or move slightly.
Since the problem to be achieved with respect to the configuration of the present embodiment and the output difference of the vibrator is the same as that of the first embodiment, description thereof will be omitted, and here, driving during characteristic detection different from that of the first embodiment. Only the method and the characteristic detection operation will be described.

First, a method for detecting output characteristics in the vibration type driving apparatus of the present embodiment will be described with reference to FIG.
FIG. 9 is a diagram showing the direction of action of the driving force in the vibration type driving apparatus of the present embodiment.
In FIG. 9, a driven body 3 that is relatively driven by two vibrators is arranged.
The configuration of the vibrator 8a and the vibrator 8b shown in FIG. 9 is the same as that of the first embodiment shown in FIG. 8. By switching the direction to the displacement of the second amplitude, the drive direction of the vibrator is changed. Can be switched.
A driving force opposite to the direction of the driving force of the vibrator 8a is generated on the predetermined protrusion 6b of the vibrator 8b shown in FIG.
The driven body 3 shown in FIG. 9 is provided with position detection means (not shown) to detect the position.
Here, at the same time that the vibration of the first vibration mode and the second vibration mode is excited in the vibrator 8a, the driving force 91a is generated, and the ellipticity ratio is fixed, the vibrator 8b also has the first vibration mode. The vibration of the vibration mode and the second vibration mode is excited to generate the driving force 91b so that the position of the driven body 3 does not move.
Thus, the magnitude of the second amplitude is changed by adjusting the driving frequency of the driving force 91b so as to balance the output of the driving force 91a, and the vibrator 8a and the vibration are vibrated based on the adjusted driving frequency. A difference in output characteristics of the child 8b (relation of output characteristics) can be detected.

Next, a method for detecting output characteristics and a control operation in the control device of the vibration type driving device of the present embodiment will be described.
Since the control operation of the control device of the vibration type drive device of this embodiment is the same as that of the first embodiment shown in the block diagram of FIG. 2, the description thereof will be omitted, and a method of detecting output characteristics will be described.
FIG. 10 is a flowchart for explaining a method for detecting the output characteristics of each vibrator in the vibration type driving apparatus of this embodiment.
First, in STEP 1, a command for starting the characteristic detection of the vibration type driving device is issued and the output detection operation is started.
Next, in STEP 2, the frequencies of all the vibrators are set to a predetermined frequency upper limit value.
The frequency upper limit value is determined in the same manner as in the first embodiment. Further, the phase difference of the vibrator a is set to 90 degrees, and the phase difference of the vibrator b is set to -90 degrees.
Next, in STEP 3, the speed of the driven body is detected.

The subsequent STEP 4 is a speed comparison unit. Here, Va shown in FIG. 10 is the detection speed of the driven body detected by STEP 3, and Vs is a sufficiently low speed.
In STEP4, if the speed Va detected in STEP3 is larger than Vs, the process proceeds to STEP5, and if smaller than -Vs, the process proceeds to STEP6.
Furthermore, when the absolute value of the detected speed Va is equal to or lower than Vs, it is determined that the driven body and the vibrator do not move relative to each other or move slightly, and the process proceeds to STEP7.
Here, the operations of STEP3 to STEP6 are repeated so that the driving force 91b of the vibrator 8b matches the driving force 91a of the vibrator 8a.
In STEP 7, the frequencies of the vibrator 8a and the vibrator 8b are stored.
In subsequent STEP 8, it is determined whether the frequency applied to the vibrator has reached the lower frequency limit. If not reached, proceed to STEP 9; if reached, proceed to STEP 10. The lower frequency limit is determined in the same manner as in the first embodiment.
In STEP 9, the frequency is lowered. In this output detection operation, the driving frequency of the vibration type driving device is swept from a high frequency to a low frequency. For this reason, the frequency is lowered, and then the process proceeds to STEP 3 to repeat the above operation.
In STEP 10, the output detection operation ends.

Next, adjustment by the output characteristic adjusting means 17 shown in FIG. 2 in the control device of the vibration type driving device of the present embodiment will be described.
The adjustment value of the output characteristic adjustment operation is obtained from the driving frequency of the vibrator 8b at the driving frequency of the vibrator 8a.
The graph shown in FIG. 11 is a detection result of the output characteristic detection operation. The graph shown in FIG. 11 is a diagram showing the frequency of the vibrator 8b when an arbitrary frequency is applied to the vibrator 8a and the vibrator is not relatively moved or slightly moved. For example, when the characteristics of the vibrator 8a and the vibrator 8b match, a 1: 1 line shown in FIG. 11 is obtained.
For example, when the frequency f31 shown in FIG. 11 is set for the vibrator 8a, the outputs of the vibrator 8a and the vibrator 8b can be matched by applying the frequency f32 to the vibrator 8b.
When f31 is set in the vibrator 8a, the drive frequency of the vibrator 8b can be derived by subtracting the adjustment value f34 from the drive frequency of the vibrator 8a.
Further, adjustment values for all the driving frequencies may be stored in a memory (not shown), and the driving frequency of the vibrator 8b may be derived.

According to this embodiment, by detecting the output characteristics of any one of the two vibrators of at least the first vibrator and the second vibrator, the output of each vibrator is detected. Differences in characteristics can be detected and variations can be adjusted.
That is, in a vibration type driving apparatus that relatively drives at least one driven body by at least two vibrators, a driving force is generated at one protrusion of at least two vibrators. Then, by generating a driving force in the reverse direction so that the driven body does not relatively move or slightly moves in the other protrusion of the at least two vibrators, the driving force in the reverse direction is reduced. Individual differences between at least two transducers can be detected from the information.
According to such a configuration, even when there is individual variation caused by the manufacturing process or shape of the vibrator, it is possible to drive by adjusting the output characteristics based on the detected individual difference.

[Third Embodiment]
As a third embodiment, a configuration example in which a ring-shaped driven body is rotationally driven by three vibrators will be described.
In the first and second embodiments described above, the vibration type driving device that relatively drives one driven body by two vibrators has been described as an example, but the configuration of the vibration type driving device is described here. It is not limited.
For example, the one shown in FIG. 12 is also applicable.
The vibrator shown in FIG. 12 has the same configuration as that of the first and second embodiments described above. In this embodiment, three such vibrators are used, and a ring-shaped driven body is formed by the three vibrators. Is configured to rotate.
The ring-shaped driven body cannot be operated except for rotation by a guide (not shown).
In this configuration, the output characteristics of each vibrator can be detected by the same method as in the first embodiment.
That is, in FIG. 12, the driving force is generated by setting the applied voltage phase difference of the vibrator 8c to 90 degrees, and the other vibrators 8d and 8e are set to 0 degrees to reduce the frictional force and not generate the driving force. To.
In this state, the frequency-speed characteristic of the vibrator 8c can be obtained by detecting the speed while sweeping the drive frequency of the vibrator 8c from the high side to the low side.
Similarly, driving force is applied to the vibrator 8d, and the other vibrators can reduce the frictional force and obtain the characteristics of the vibrator 8d in a state where no driving force is generated. Similarly, the characteristics of the vibrator 8e can be obtained.

It is also possible to detect each characteristic by the same method as in the second embodiment.
That is, a driving force for the driven body to move clockwise is applied to the vibrator 8c, and at the same time, a driving force for the driven body to move counterclockwise is applied to the vibrator 8d. In order to reduce the frictional force, only vibration perpendicular to the contact surface is applied. In this state, the frequency of the vibrator 8c is swept from higher to lower, and the frequency of the vibrator 8d is adjusted so that the driven body does not move, thereby obtaining the relationship between the frequencies of the vibrator 8c and the vibrator 8d. Can do. Similarly, it is possible to obtain a frequency relationship in the combination of other vibrators.
By performing control based on the relationship between the frequency and speed of each vibrator obtained by the above method, the driven body 2 can be driven without impairing efficiency.

2: driven body 3: driven body 4, 4a, 4b: elastic bodies 5, 5a, 5b: piezoelectric elements 6, 6a, 6b: protrusion 7: driven body 8a, 8b: vibrator 10: vibration type drive Device 11: Drive signal generation means a
12: Drive signal generation means b
14: Position detection means 15: Speed detection means 16: Output characteristic detection means 17: Output characteristic adjustment means 18: Control calculation means

Claims (10)

A plurality of vibrators each having an electro-mechanical energy conversion element and a drive unit; and a driven body that is in contact with the drive units of the plurality of vibrators; by applying an AC voltage to the electro-mechanical energy conversion element A control device for a vibration-type driving device that causes an elliptical motion in the driving units of the plurality of vibrators and relatively moves the driven body in contact with the driving unit,
Drive signal generating means for applying the AC voltage to each vibrator of the plurality of vibrators;
A drive frequency and a phase difference of an alternating voltage applied to each vibrator in the plurality of vibrators are determined, and the determined drive frequency and the phase difference are output to the drive signal generation means to output the drive signal generation means. Control means for controlling;
Output characteristic detection means for detecting output characteristics of each vibrator in the plurality of vibrators by comparing the drive speed of the driven body and the drive frequency in the drive signal generation means;
Under the control of the control means,
A vibration in a first vibration mode that displaces the drive unit in a direction perpendicular to a contact surface with the driven body with respect to a detection target vibrator that detects output characteristics of the plurality of vibrators; The drive signal generating means generates an AC voltage that causes elliptical motion in the drive unit by exciting the vibration in the second vibration mode that displaces the drive unit in a direction parallel to the contact surface with the driven body. While applying
Only the AC voltage that excites the vibration in the first vibration mode is applied to the vibrator other than the vibrator to be detected by the drive signal generation unit,
A control device for a vibration type driving apparatus, wherein the output characteristic detecting means detects an output characteristic of the vibrator to be detected. The transducer to be detected includes a single transducer or a plurality of transducers,
2. The control of the vibration type driving device according to claim 1, wherein the output characteristic detection unit detects an output from the one vibrator or a synthesized output from the plurality of vibrators. apparatus. A plurality of vibrators each having an electro-mechanical energy conversion element and a drive unit; and a driven body that comes into contact with the drive units of the plurality of vibrators.
A control device for a vibration type driving device that causes an elliptical motion to occur in the driving portions of the plurality of vibrators by applying an alternating voltage to the electro-mechanical energy conversion element, and relatively moves the driven body in contact with the driving portions. Because
Drive signal generating means for applying the AC voltage to each vibrator of the plurality of vibrators;
A drive frequency and a phase difference of an alternating voltage applied to each vibrator in the plurality of vibrators are determined, and the determined drive frequency and the phase difference are output to the drive signal generation means to output the drive signal generation means. Control means for controlling;
Output characteristic detecting means for detecting the relationship between the output characteristics of each vibrator in the plurality of vibrators,
The plurality of vibrators include at least two vibrators including a first vibrator and a second vibrator, and are controlled by the control unit.
With respect to the first vibrator, vibration in a first vibration mode for displacing the drive unit in a direction perpendicular to the contact surface with the driven body, and in a direction parallel to the contact surface with the driven body While applying an AC voltage that causes an elliptical motion in the drive unit by exciting the vibration of the second vibration mode that displaces the drive unit,
An AC voltage that generates a driving force in a direction that cancels the driving force due to the elliptical motion of the driving unit of the first vibrator is applied to the second vibrator by the driving signal generation unit,
A control device for a vibration type driving apparatus, wherein the output characteristic detecting means detects a relationship between an output characteristic of the first vibrator and an output characteristic of the second vibrator. The driving force generated in the second vibrator in the direction to cancel the driving force due to the elliptical motion of the driving part of the first vibrator is
The amplitude of displacement in the direction parallel to the contact surface with the driven body caused by the second vibration mode generated in the driving unit of the second vibrator is changed by adjusting a driving frequency, and the driven body is The driving force is generated so that the relative movement does not occur.
Based on the adjusted driving frequency for changing the amplitude of the second vibrator driving unit in the second vibration mode, the output characteristics of the first vibrator and the output characteristics of the second vibrator The control device for the vibration type driving device according to claim 3, wherein the relationship is detected. The plurality of vibrators further include a third vibrator in addition to the first vibrator and the second vibrator,
5. The control device of the vibration type driving device according to claim 4, wherein an AC voltage that excites only the vibration in the first vibration mode is applied to the third vibrator by the driving signal generation unit. A plurality of vibrators each having an electro-mechanical energy conversion element and a drive unit; and a driven body that comes into contact with the drive units of the plurality of vibrators.
Output characteristics of a vibration-type driving device that causes an elliptical motion in the driving units of the plurality of vibrators by applying an AC voltage to the electro-mechanical energy conversion element, and relatively moves the driven body in contact with the driving units. A detection method,
A vibration in a first vibration mode that displaces the drive unit in a direction perpendicular to a contact surface with the driven body with respect to a detection target vibrator that detects output characteristics of the plurality of vibrators; While applying an alternating voltage that causes elliptical motion in the drive unit by exciting the vibration of the second vibration mode that displaces the drive unit in a direction parallel to the contact surface with the driven body,
An alternating voltage that excites vibration in only the first vibration mode is applied to a vibrator other than the vibrator to be detected,
An output characteristic detection method for a vibration type driving apparatus, characterized by detecting an output characteristic of a vibrator to be detected.   The vibrator to be detected is a vibrator by one vibrator or a plurality of vibrators, and an output by the one vibrator or a synthesized output by the plurality of vibrators is detected. The output characteristic detection method of the vibration type drive device according to claim 6. A plurality of vibrators each having an electro-mechanical energy conversion element and a drive unit; and a driven body that comes into contact with the drive units of the plurality of vibrators.
Output characteristics of a vibration-type driving device that causes an elliptical motion in the driving units of the plurality of vibrators by applying an AC voltage to the electro-mechanical energy conversion element, and relatively moves the driven body in contact with the driving units. A detection method,
The plurality of vibrators include at least two vibrators including a first vibrator and a second vibrator,
With respect to the first vibrator, vibration in a first vibration mode for displacing the drive unit in a direction perpendicular to the contact surface with the driven body, and in a direction parallel to the contact surface with the driven body While applying an alternating voltage that causes elliptical motion in the drive unit by exciting vibrations in a second vibration mode that displaces the drive unit,
An alternating voltage that generates a driving force in a direction that cancels the driving force due to the elliptical motion of the driving unit of the first vibrator is applied to the second vibrator,
A method of detecting an output characteristic of a vibration type driving apparatus, wherein a relationship between an output characteristic of the first vibrator and an output characteristic of the second vibrator is detected. The driving force generated in the second vibrator in the direction to cancel the driving force due to the elliptical motion of the driving part of the first vibrator is
The amplitude of displacement in the direction parallel to the contact portion with the driven body by the second vibration mode generated in the driving section of the second vibrator is changed by adjusting a driving frequency, and the driven body is The driving force is generated so that the relative movement does not occur.
Based on the adjusted driving frequency for changing the amplitude of the second vibrator driving unit in the second vibration mode, the output characteristics of the first vibrator and the output characteristics of the second vibrator The method for detecting output characteristics of a vibration type driving apparatus according to claim 8, wherein the relationship is detected.   The plurality of vibrators further include a third vibrator in addition to the first vibrator and the second vibrator, and the third vibrator excites only the vibration in the first vibration mode. 10. The method for detecting output characteristics of a vibration type driving apparatus according to claim 9, wherein an alternating voltage is applied.

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