JP4208627B2 - Control device, operation device, and control method for vibration type drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to control of a so-called vibration type driving device that forms a progressive vibration in an elastic body by an electro-mechanical energy conversion element and moves the vibration body and a contact body relative to each other.
[0002]
[Prior art]
2. Description of the Related Art A vibration type driving device that generates vibration in an elastic body by an electro-mechanical energy conversion element and drives a moving body (contact body) is used as an actuator that can extract a large driving force at a low speed.
[0003]
In particular, the traveling wave type vibration type driving device proposed in Patent Document 1 excites a traveling vibration wave in an elastic body and continuously drives a moving body in pressure contact with the elastic body, Smoother driving is possible.
[0004]
In the vibration type driving device described in Patent Document 1, the vibrating body is configured by using an annular elastic body, and a comb-shaped projection group is formed on one side in the axial direction of the elastic body. . A friction material is bonded to the upper surfaces of these projection groups. In addition, an annular piezoelectric element as an electro-mechanical energy conversion element is bonded to the other axial side of the elastic body, and a pattern electrode is formed on the piezoelectric element.
[0005]
The pattern electrode is equally divided into four times the order corresponding to the order of the vibration mode excited in the annular portion of the vibrating body, and each electrode has an approximately 90 ° temporal phase difference in order. A sinusoidal AC voltage is applied. When an alternating voltage is applied at a frequency near the natural frequency of the vibration mode to be excited, the elastic body resonates due to a bending moment applied to the elastic body due to expansion and contraction of the piezoelectric element, and vibrations that are excited with respect to alternating voltages that differ by 90 °. The (mode) has the same shape and different phases, and a traveling forward vibration wave (traveling wave) is formed by the synthesis.
[0006]
FIG. 17 shows a driving circuit for driving the vibration type driving device. This drive circuit is a drive circuit described in Patent Document 2, and a switching circuit composed of MOSFETs 22 to 29 is turned on / off with a pulse generated by a pulse generation means (not shown), with a center tap. AC voltage is generated in the transformers 30 and 31, and the terminals 32 to 35 corresponding to the A (+), B (+), A (−), and B (−) phases connected to the secondary side are successively 90 °. Apply an AC voltage that is out of phase.
[0007]
On the other hand, a so-called standing wave drive type motor in which different vibrations (modes) are superimposed includes, for example, one that synthesizes longitudinal vibration and torsional vibration as proposed in Patent Document 3. In this example, longitudinal vibration and torsional vibration are excited with a phase difference of 90 °, whereby longitudinal vibration is used as vibration for separating and contacting the moving body with respect to the moving body, and torsional vibration is used as vibration for conveying the moving body. ing.
[0008]
Such a vibration type driving device driven by superposition of different vibration modes needs to substantially match the resonance frequency with the modes of different vibration directions in order to drive the modes of different vibration directions at the same frequency. However, even if the same shape is processed, it is difficult to match the resonance frequency due to the anisotropy of the material of the vibrating body, and a frequency adjustment step is required.
[0009]
On the other hand, the so-called traveling wave type vibration type driving device by superimposing vibrations (modes) of the same shape described above is a mode in which the vibration modes have the same deformation distribution, so that the resonance frequency changes depending on the vibration direction. Is less likely to occur and requires little adjustment to match the resonant frequencies of the two modes.
[0010]
[Patent Document 1]
JP 2001-157473 A
[Patent Document 2]
JP 2002-176788 A
[Patent Document 3]
JP-A-8-242593
[Patent Document 4]
JP-A-8-80073
[0011]
[Problems to be solved by the invention]
However, the traveling wave type vibration type driving device has the following problems because it is a superposition of vibrations (modes) of the same shape.
[0012]
FIG. 18 schematically shows a contact / drive state between the vibrating body (elastic body) and the moving body.
[0013]
FIG. 18 shows the vibration displacement of the vibrating body 101 and the response displacement of the moving body 106, and the protrusion shape and friction material on the vibrating body are omitted. In the figure, solid arrows indicate the driving vibration of the vibrating body 101, and the moving body 106 is driven in the direction indicated by the white arrow by this driving vibration. (A) shows the vibration state during high speed driving with a large vibration amplitude, and (b) shows the vibration state during low speed driving with a vibration amplitude smaller than in the case of (a). As shown in (b), by reducing the vibration amplitude, the feed speed at each position is lowered and the speed is lowered (the speed is indicated by the length of the white arrow).
[0014]
The moving body 106 has its bending rigidity and responsiveness so that a part of the moving body 106 is in contact with the vibration shape of the vibrating body 101 at a high feed rate, that is, a large displacement. However, as the speed is lowered, the contact area with the moving body 106 increases, and finally, as shown in FIG.
[0015]
In such a contact state, efficiency is lowered because sliding friction due to a partial speed difference between the vibrating body and the moving body acts on almost the entire contact surface. Furthermore, since the abrasion powder generated on the contact surface is difficult to be discharged to the outside and works as abrasive grains, the wear amount of the moving body and the vibrating body increases.
[0016]
As a method for reducing the speed while maintaining a certain vibration amplitude, it is mainly as a means for improving the response of vibration, but for example, as proposed in the above-mentioned Patent Document 4, it is changed to a standing wave when stopped. There are a method of switching and a method of changing the phase difference between the A phase and the B phase from 90 ° to change to a standing wave.
[0017]
However, such a method adversely affects the contact surface between the vibrating body and the moving body.
[0018]
For example, in the case of an annular type vibration type driving device, vibration modes that cause a plurality of bending deformations in a vibrating body are used with the positional phase shifted by 90 ° and overlapped.
[0019]
FIG. 19 is a developed view schematically showing the vibration of the vibrating body, and shows the state of vibration when drive voltages having a time phase different by 90 ° are applied to A and B of the piezoelectric element 102, respectively. Ellipses a to g shown in the respective parts of the vibrating body 101 indicate elliptical motions generated at respective positions of the vibrating body. The arrows shown in each ellipse are the vibration components of the A and B phases (the solid arrow indicates the A phase and the dotted arrow indicates the B phase) constituting the elliptical motion.
[0020]
The direction of the vibration component of each phase of A and B constituting the elliptical motion differs depending on the position. Here, when the standing wave component is generated by reducing the vibration amplitude of the A phase, the location where the longitudinal amplitude decreases and the location where the lateral amplitude decreases are distributed depending on the location, resulting in uneven frictional state. Is produced. This non-uniformity causes a difference in the wear speed of the friction surface, so that the flatness of the friction surface is degraded and the performance is degraded.
[0021]
Furthermore, since the maximum part of the traveling wave vibration, that is, the portion where the driving force is large is always present at the same position, unevenness of the surface pressure between the moving body and the vibrating body occurs, or the moving body is caused by unevenness in the plane of the contact portion of the moving body Rotation unevenness may occur in synchronization with the rotation of the rotation, which may reduce the rotation accuracy.
[0022]
SUMMARY OF THE INVENTION An object of the present invention is to provide a control device and a control method for a vibration type drive device that can maintain output performance even if the drive state at low speed is continued for a long period of time.
[0023]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, a vibration body having an elastic body and an electro-mechanical energy conversion element, and a contact body in contact with the vibration body, the electro-mechanical energy conversion element has a plurality of drives. A vibration type that applies a signal to excite progressive vibrations (by synthesizing these vibrations by exciting multiple vibrations with the same shape and different positional phases) and moving the vibrating body relative to the moving body. Provided is a drive control device. Here, the control device controls the drive signal so that the maximum displacement of the progressive vibration increases and decreases and the position where the maximum displacement becomes maximum changes in the relative movement direction of the vibrating body and the moving body.
[0024]
Alternatively, the control device may output a plurality of drive signals with different temporal phases so that the maximum displacement of the progressive vibration increases and decreases, and the position where the maximum displacement becomes maximum changes in the relative movement direction of the vibrating body and the moving body. Control periodically.
[0025]
Alternatively, the control device controls the drive signal so that the progressive vibration includes a vibration component that changes the positional phase of the progressive vibration.
[0026]
In order to achieve the above object, the present invention includes a vibrating body having an elastic body and an electro-mechanical energy conversion element, and a contact body in contact with the vibrating body, and a plurality of electro-mechanical energy conversion elements. Is applied to the vibrating body to excite a plurality of vibrations having the same shape and different positional phases (by combining these vibrations) to move the vibrating body and the moving body relative to each other. Provided is a method for controlling a vibration type driving apparatus. Here, the control method is characterized in that the drive signal is controlled such that the maximum displacement of the progressive vibration increases and decreases and the position where the maximum displacement becomes maximum changes in the relative movement direction of the vibrating body and the moving body. To do.
[0027]
Alternatively, the control method is characterized in that the driving signal is controlled so that the progressive vibration includes a vibration component that changes a positional phase of the progressive vibration.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
(Embodiment 1)
FIG. 12 shows a configuration of a traveling wave type vibration type driving apparatus according to the first embodiment of the present invention. This vibration type driving device is rotatably supported on the housing 10 by a vibrating body 1 fixed to the housing 10 with a screw, a moving body 6 in frictional contact with the vibrating body 1 via a friction material 5, and a ball bearing 15. The output shaft 11 and the pressure spring 8 that generates a spring force that pressurizes the moving body 6 against the vibrating body 1 and transmits the rotation of the moving body 6 to the output shaft 11 are configured. The output shaft 11 is connected to a drive mechanism 20 of an operation device such as various devices or devices using the vibration type drive device as a drive source via a gear (not shown). The drive mechanism 20 is connected to the output shaft 11. Operates in response to the output from.
[0029]
In FIG. 13, the perspective view seen from the back surface side of the vibrating body 1 used for the said vibration type drive device is shown. The vibrating body 1 includes an elastic body 1A that is manufactured in an annular shape by mold forming such as metal material cutting or powder sintering, and a circle as an electro-mechanical energy conversion element attached to the back surface of the elastic body 1A. And an annular piezoelectric element 2.
[0030]
A plurality of comb-like projections 4 are formed on one axial surface (front surface) side of the elastic body 1A by forming a plurality of radial grooves extending in the axial direction. A friction material 5 is bonded to the upper surfaces of the plurality of protrusions 4. As the friction material, a composite resin material mainly composed of PTFE, a metal material subjected to a surface treatment according to the use, or alumina ceramic is used.
[0031]
The piezoelectric element 2 is bonded to the surface of the elastic body 1A on the other side in the axial direction (the side on which the comb-like projections are not formed), and a pattern electrode 2-1 is deposited or printed on the piezoelectric element 2. Is formed by.
[0032]
The pattern electrode 2-1 is equally divided into four times the order corresponding to the order of vibration (hereinafter also referred to as vibration mode) excited on the elastic body 1A of the vibration body 1, Are applied with substantially sinusoidal alternating voltages whose time phases are different by 90 ° in order. When an AC voltage is applied at a frequency in the vicinity of the natural frequency of the excited vibration mode, a bending moment is applied to the elastic body 1A due to expansion and contraction of the piezoelectric element 2, thereby causing the elastic body 1A to resonate and vibrate. Vibrations excited with respect to alternating voltages that differ by 90 ° become traveling waves (progressive vibration waves) by their synthesis.
[0033]
Next, a driving method (control method) of the vibration type driving device will be described. FIG. 1 shows vibration trajectories of the A phase and the B phase of the vibrating body. FIG. 2 shows a pattern of an input signal (drive signal) applied to the piezoelectric element 2 via the pattern electrode. Further, FIG. 13 shows a description of the drive signal waveform.
[0034]
The vibration trajectory shown in FIG. 1 shows the vibration displacement of the A phase and the B phase as the horizontal axis and the vertical axis, and the vibration as shown in FIG. 1 is excited in the vibrator 1 by the drive signal shown in FIG. Is done.
[0035]
Here, in the case of four-phase driving in which a driving signal is applied to the piezoelectric elements 2 of A (+), B (+), A (−), and B (−), A (+), A (−), and B Since (+) and B (-) are in opposite phases, they are omitted and shown as A phase and B phase (the same applies to other embodiments hereinafter).
[0036]
The drive signals (A-phase drive voltage and B-phase drive voltage) shown in FIG. 2 are amplitude-modulated (standing wave amplitude a) with the drive signal having the drive angular velocity ω shown in FIG. 3 as the fundamental wave (drive voltage V). And phase modulation (turning angle α) are simultaneously applied. As a result, a standing wave component is generated in the traveling wave as shown in FIG. 1, and the standing wave component is rotated on the A and B planes. A traveling wave is formed.
[0037]
Next, the operation of this driving method will be described. In the driving method of a normal vibration type driving device, the A phase vibration and the B phase vibration arranged with a positional phase of π / 2 are equal in amplitude and excited with a temporal phase of π / 2. Thus, the circular trajectory indicated by the broken line in FIG. As shown in FIG. 19, the vibration directions of the A and B phases are different in each part of the vibrating body.
[0038]
FIG. 4 is a schematic diagram showing the vibration mode of the present embodiment shown in FIG. 1 with the vibration of each part of the vibrating body 1 divided into A phase and B phase components over time (a), (b ), (C) and (d). A solid line arrow is a vibration component of A phase, and a dotted line arrow is a vibration component of B phase.
[0039]
In the state of (a). Since the A phase amplitude> the B phase amplitude, the vibration in the abdominal part of the A phase is maximized, and the elliptical vibration is gradually rotated. In the state (b), the vibration amplitude is intermediate between the abdominal part of the A phase and the abdominal part of the B phase. Is the maximum. Further, in the state (c), the vibration amplitude in the abdomen of the B phase becomes the maximum, and similarly, the state (d) is passed through and the vibration form returns to the original (a). In this way, by applying amplitude modulation and phase modulation, as shown in FIG. 1, the standing wave component constituted by the A-phase and B-phase vibrations is rotated.
[0040]
As a result, the position where the maximum displacement of the traveling wave formed by the synthesis of the A-phase vibration and the B-phase vibration increases and decreases and the maximum displacement becomes maximum is on the vibrating body 1 and the vibrating body 1 and the moving body 6. It moves in the relative drive direction.
[0041]
Here, FIG. 15 shows the movement of the vibration displacement in a normal (conventional) traveling wave in which the vibration amplitudes of the phases A and B are equal and the temporal phase is 90 °. In the figure, the broken line represents an envelope connecting the maximum values of the vibration displacement of the traveling wave at each position. Since the maximum values of the vibration displacement are equal, the envelope is a straight envelope. That is, the maximum displacement of the traveling wave does not increase or decrease and there is no maximum value.
[0042]
FIG. 16 shows the movement of the vibration displacement of the traveling wave when the B-phase vibration amplitude is reduced as a conventional low-speed driving method described in FIG. Since the amplitude decreases at the position corresponding to the B phase, the envelope connecting the maximum displacement of the traveling wave is half the traveling wave wavelength, which is the maximum (maximum) of the A phase position, as shown by the broken line in the figure. It becomes a substantially sine wave shape of pitch. Further, if the vibration amplitude of the B phase is reduced to 0, the amplitude at the position corresponding to the B phase becomes 0, and only the standing wave having an antinode at the A phase position is obtained. Similarly, when the vibration amplitude of the A phase is reduced, the amplitude of the position corresponding to the A phase position is reduced, resulting in an envelope on a substantially sine wave that maximizes (maximum) the B phase position.
[0043]
As described above, in the conventional driving method, the maximum value of the vibration displacement of the traveling wave increases or decreases, but the traveling wave is such that the maximum value is maximized at a predetermined position such as the A phase position or the B phase position. Then, when the vibration amplitude of one phase is reduced to generate a standing wave component in this way, the places where the longitudinal amplitude decreases and the places where the transverse amplitude decreases are distributed in a fixed place. For this reason, when the moving body is brought into pressure contact with the vibrating body, the frictional state is uneven depending on the contact position. This non-uniformity causes a difference in the wear speed of the friction surface and deteriorates the flatness of the friction surface, resulting in a decrease in performance such as increased rotation unevenness and generation of abnormal noise due to failure to maintain an appropriate contact state. Cause.
[0044]
Furthermore, since there are always places with large vibration amplitudes at the same position, the surface pressure distribution between the moving body and the vibrator is uneven, and the unevenness of the plane of the contact portion of the moving body is constantly synchronized with the rotation of the moving body. Rotation unevenness occurs, and the rotational accuracy is significantly impaired.
[0045]
Further, when the temporal phases of the A and B phases are changed from 90 °, the amplitude at the intermediate position between the A and B phases is increased, which causes the same performance degradation.
[0046]
On the other hand, FIG. 14 shows the movement of the envelope connecting the maximum positions of the vibration amplitude at each position of the traveling wave excited by the vibrating body 1 by the driving method of the present embodiment. In the conventional driving method, as shown in FIG. 16, the position of the maximum portion of the envelope connecting the maximum amplitude values is constant, whereas in this embodiment, the speed is determined by the modulation period. The envelope of the vibration displacement moves. That is, in this embodiment, the maximum value (maximum displacement) of the vibration displacement of the traveling wave increases and decreases, and the position at which the maximum displacement becomes maximum moves sequentially or continuously.
[0047]
In order for the vibrating body 1 to respond to amplitude modulation and phase modulation of the driving signal, the sideband of the driving signal generated by the modulation frequency only needs to be within a band in which the vibrating body 1 can be driven.
[0048]
The standing wave component generated by the modulation has no driving force for driving the moving body 6, and the driving vibration component capable of driving the moving body 6 is given by the orthogonal components included in the A and B phases. For this reason, the drive vibration component is only the elliptical component indicated by the broken line in FIG. 4, and the driving speed is also determined by the size of the broken elliptical line.
[0049]
According to this embodiment, it is possible to drive at a lower speed while generating a vibration larger than the driving vibration component, and further, the position where the maximum displacement of the traveling wave is maximized on the vibrating body 1 according to the modulation period. Since it moves continuously, it is possible to avoid the entire contact state with the moving body 6, and it is also possible to avoid the phenomenon that wear progresses at a specific location.
[0050]
Furthermore, in the conventional driving method, the pressing surface pressure unevenness of the moving body occurs, or the rotation unevenness and torque unevenness occur due to the relationship between the planar shape of the contact portion and the maximum position of the traveling wave on the vibrating body. According to this embodiment, it is possible to average the rotation unevenness and torque unevenness within the modulation period of the amplitude phase by moving the maximum position of the traveling wave on the vibrating body, and the rotation unevenness below the modulation frequency. Torque unevenness can be greatly reduced.
[0051]
As described above, in the present embodiment, independent amplitude modulation and phase modulation are applied to the A-phase vibration and the B-phase vibration so that the traveling wave, which is a composite wave of the A-phase and the B-phase, includes the standing wave component. By rotating the vibration shape on the AB plane, the maximum position of the maximum displacement of the traveling wave formed on the vibrating body 1 can be moved sequentially (continuously). Therefore, it is possible to drive stably with a large amplitude over a long period of time even under conditions where the driving vibration is very small due to extremely low speed driving.
[0052]
(Embodiment 2)
FIG. 5 shows a vibration locus of the vibrating body 1 when driven by the driving method (control method) of the vibration type driving apparatus according to the second embodiment of the present invention. The driving method of this embodiment is applied to the vibration type driving device described in the first embodiment. Also in this embodiment, as in the first embodiment, the maximum position of the maximum displacement of the traveling wave formed on the vibrating body 1 can be sequentially moved.
[0053]
FIG. 6 shows an input signal (drive signal) of this embodiment. FIG. 7 shows the drive amplitude of the present embodiment on the time axis.
[0054]
In the present embodiment, only independent amplitude modulation is applied to the A phase and the B phase.
[0055]
As shown in FIG. 6, when the basic amplitude is V and the amplitude modulation of the modulation amplitude a is reversed between the A phase and the B phase, when viewed in a time longer than the drive cycle, both the A and B phases The amplitude is increased evenly.
[0056]
In the case of the present embodiment, the vibration forms shown in FIGS. 4A and 4C are obtained. For this reason, the amplitude corresponding to the antinodes of the A phase and the B phase increases, and the amplitude decreases in the region between the A phase abdomen and the B phase abdomen. A uniform contact state cannot be obtained over the entire area. Therefore, there is a possibility that uneven rotation may increase due to the uneven wear, but such uneven friction occurs evenly in both the A phase and the B phase, so that there is no drive imbalance. Therefore, it is effective as a simple driving method that does not use phase modulation as in the first embodiment.
[0057]
(Embodiment 3)
FIG. 8 shows a vibration locus of the vibrating body 1 when driven by the driving method (control method) of the vibration type driving apparatus according to the third embodiment of the present invention. The driving method of this embodiment is applied to the vibration type driving device described in the first embodiment. Also in this embodiment, as in the first embodiment, the maximum position of the maximum displacement of the traveling wave formed on the vibrating body 1 can be sequentially moved.
[0058]
In FIG. 9, the amplitude change of both A and B phases in this embodiment is shown.
[0059]
Also in the present embodiment, as in the second embodiment, the drive signals of both A and B phases are only subjected to independent amplitude modulation, but the amplitude modulation of both A and B phases is not a single frequency. Is different. In the present embodiment, there is a possibility that a change in the feed rate is caused by the modulation and the rotation unevenness is increased, but this is effective as a simpler driving method compared to the second embodiment.
[0060]
Furthermore, as shown in FIG. 10, the amplitude modulation may be stepped or rectangular.
[0061]
(Embodiment 4)
In FIG. 11, the structure of the control apparatus of the vibration type drive device which is Embodiment 4 of this invention is shown.
[0062]
This control device is a control device that performs speed control of the vibration type drive device (vibration type drive device shown in FIG. 1) 110, and speed information from a speed detector 117 such as an encoder provided in the vibration type drive device 110. From the speed command value given from the outside (for example, the main control circuit of the operating device using the vibration type driving device 110 as a driving source), the frequency control circuit 112 determines the frequency of the driving signal according to the deviation between them. Further, similarly, the amplitude and phase modulation circuit 113 determines the amplitude modulation amount, the phase modulation amount, and the period of amplitude modulation and phase modulation according to the speed deviation.
[0063]
As each modulation parameter, an optimum modulation amount (modulation width) and modulation period with respect to the speed are stored in a memory (not shown), and a modulation parameter corresponding to the speed detected by the speed detector 117 is stored in the memory. Is read from and determined. For example, depending on the speed range, no modulation is performed on the high speed side, and the modulation amplitude is increased as the speed is decreased on the low speed side.
[0064]
A phase difference is given to one of the outputs from the frequency control circuit 112 based on the phase determined by the amplitude / phase modulation circuit 113, and the signal to which the phase difference is given and the other signal are used as A-phase and B-phase drive waveforms, respectively. Similarly, the amplitude control circuits 115 and 116 provided independently for the A phase and the B phase are respectively set with two-phase amplitude values determined by the amplitude phase modulation circuit 113, and the amplitude control circuits 115 and 116 are respectively set. A drive signal is applied to the A-phase and B-phase piezoelectric elements of the vibration type driving device 110 through an amplifier circuit (not shown).
[0065]
In this embodiment, since the amount of amplitude / phase modulation is determined according to the driving speed of the vibration type driving device 110, when the driving speed is large and the amplitude is large, the modulation amount can be reduced. Since the modulation can be increased at a minute speed related to the performance degradation of 110, appropriate modulation can be applied according to the driving situation.
[0066]
In the present embodiment, only the speed control of the vibration type driving device has been described. However, in the positioning control of the vibration type driving device, the target value obtained by the position detector provided in the vibration type driving device 110 is similarly determined. From these deviations, the speed and modulation parameters may be determined. In the case of driving with a plurality of phases, the modulation circuits may be provided for the number of driving phases.
[0067]
Further, as the amplitude control circuits 115 and 116 described above, those such as variable gain amplifiers may be used, and a pulse width control circuit and an amplifier circuit may be configured using pulses as drive signals.
[0068]
Note that the configuration of the control device described in this embodiment is merely an example, and any control signal can be used as long as the drive signal is controlled so as to sequentially move the maximum position of the maximum displacement of the traveling wave formed on the vibrating body 1. Such a configuration may be adopted.
[0069]
In this embodiment, the case where the drive signal is controlled by hardware has been described. However, similar control can be performed by a computer program.
[0070]
In each of the above embodiments, the control of the annular vibration type driving device has been described. However, the present invention excites a plurality of vibrations having the same shape (or the same type) and different temporal phases on the vibrating body. As long as it is a vibration type driving device that excites progressive vibration by its synthesis, it can be applied to any form.
[0071]
Furthermore, each embodiment described above is an example when the present invention is implemented. The present invention is also implemented by adding various changes and improvements to the above-described embodiments.
[0072]
【The invention's effect】
As described above, according to the present invention, even when the vibration type driving device is driven at a low speed, the amplitude of the progressive vibration can be increased and the position where the maximum displacement is maximized is moved. Further, it is possible to suppress the occurrence of a phenomenon that causes performance deterioration that causes uneven wear on the vibrating body and the contact body. Therefore, it is possible to perform stable driving with less speed unevenness of the vibration type driving device and to maintain stable performance of the vibration type driving device over a long period of time.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a vibration locus of a vibrating body in a vibration type driving device controlled by a control device according to a first embodiment of the present invention.
FIG. 2 is a diagram showing an input signal pattern in the first embodiment.
FIG. 3 is a diagram showing an equation of an input signal waveform in the first embodiment.
FIG. 4 is a schematic diagram showing vibration of a vibrating body in the first embodiment.
FIG. 5 is a diagram illustrating a vibration locus of a vibrating body in a vibration type driving device controlled by a control device according to a second embodiment of the present invention.
FIG. 6 is a diagram showing an equation of an input signal waveform in the second embodiment.
FIG. 7 is a chart showing drive amplitude in the second embodiment.
FIG. 8 is a diagram illustrating a vibration locus of a vibrating body in a vibration type driving device controlled by a control device according to a third embodiment of the present invention.
FIG. 9 is a chart showing drive amplitude in the third embodiment.
FIG. 10 is a chart showing drive amplitude in the third embodiment.
FIG. 11 is a block diagram showing a configuration of a control apparatus that is Embodiment 4 of the present invention.
FIG. 12 is a cross-sectional view showing a configuration of a traveling wave type vibration drive device of each of the embodiments.
FIG. 13 is a perspective view of a vibrating body used in the vibration type driving device.
FIG. 14 is a diagram showing the movement of an envelope of vibration displacement of traveling waves excited by the control device of the first embodiment.
FIG. 15 is a diagram showing a movement of vibration displacement of a traveling wave excited by a conventional control method.
FIG. 16 is a diagram showing the movement of vibration displacement of traveling waves excited by a conventional control method.
FIG. 17 is a diagram showing a configuration of a driving circuit of a conventional vibration type driving device.
FIG. 18 is a development view showing a contact state and a driving state of a vibrating body and a moving body in a conventional traveling wave type vibration type driving device.
FIG. 19 is a schematic diagram showing vibration of a vibrating body in a conventional vibration type driving device.
[Explanation of symbols]
1 Vibrating body
1A Elastic body
2 Piezoelectric elements
2-1 Pattern electrode
4 Comb teeth
5 Friction material
6 Mobile
8 Pressure spring
9 discs
10 Housing

Claims (27)

A vibrating body having an elastic body and an electro-mechanical energy conversion element; and a contact body in contact with the vibrating body, and applying a plurality of drive signals to the electro-mechanical energy conversion element to travel to the vibrating body A control device for a vibration type driving device that excites sexual vibration and relatively moves the vibrating body and the moving body,
A vibration type drive characterized in that the drive signal is controlled such that the maximum displacement of the progressive vibration increases and decreases and the position where the maximum displacement becomes maximum changes in the relative movement direction of the vibration body and the moving body. Control device for the device. A vibrating body having an elastic body and an electro-mechanical energy conversion element; and a contact body in contact with the vibrating body, and applying a plurality of drive signals to the electro-mechanical energy conversion element to travel to the vibrating body A control device for a vibration type driving device that excites sexual vibration and relatively moves the vibrating body and the moving body,
The plurality of drive signals are periodically changed with different temporal phases so that the maximum displacement of the progressive vibration increases and decreases and the position where the maximum displacement is maximized changes in the relative movement direction of the vibrating body and the moving body. A control device for a vibration type drive device, characterized by controlling. 3. The control device for the vibration type driving device according to claim 1, wherein amplitudes and phases of the plurality of driving signals are periodically changed with different temporal phases. 4. 3. The control device for the vibration type drive device according to claim 1, wherein amplitudes of the plurality of drive signals are periodically changed with different temporal phases. 4. 5. The control device for a vibration type drive device according to claim 1, wherein the drive signal is controlled so as to change a maximum displacement of the progressive vibration with respect to a change in frequency of the drive signal. 6. . Speed detecting means for detecting the speed of the vibration type driving device;
5. The control device for a vibration type drive device according to claim 1, wherein the drive signal is controlled to change a maximum displacement of the progressive vibration according to a detection result of the speed detection unit. . A vibrating body having an elastic body and an electro-mechanical energy conversion element; and a contact body in contact with the vibrating body; applying a plurality of drive signals to the electro-mechanical energy conversion element; A control device for a vibration type driving device that excites a plurality of vibrations having the same shape and different positional phases, and relatively moves the vibrating body and the moving body by a progressive vibration generated by combining these vibrations,
A control device for a vibration-type drive device, wherein the drive signal is controlled so that the progressive vibration includes a vibration component that changes a positional phase of the progressive vibration. 8. The control device for a vibration type drive device according to claim 7, wherein the amplitude and phase of the plurality of drive signals are periodically changed with different temporal phases. The amplitude of the plurality of drive signals is periodically changed with a real time phase so that the position of the maximum portion of the progressive vibration changes in the relative movement direction of the vibrating body and the moving body. The control device of the vibration type driving device according to claim 7. 8. The control device of the vibration type drive device according to claim 7, wherein a vibration component that changes a positional phase of the progressive vibration is increased or decreased with respect to a change in frequency of the drive signal. Speed detecting means for detecting the speed of the vibration type driving device;
8. The control device of the vibration type driving device according to claim 7, wherein a vibration component that changes a positional phase of the progressive vibration is increased or decreased according to a detection result of the speed detection means. Speed detecting means for detecting the driving speed of the vibration type driving device;
Frequency control means for determining a drive frequency from the deviation between the speed signal obtained by the speed detection means and a given speed command value;
Modulation means for determining a phase modulation amount and an amplitude modulation amount in accordance with a predetermined parameter with respect to the driving speed of the vibration type driving device;
Phase control means for generating a signal obtained by phase-modulating the drive frequency in accordance with the phase modulation amount determined by the modulation means;
9. The control of the vibration type driving device according to claim 3, further comprising amplitude control means for independently performing amplitude modulation on each drive signal in accordance with the amplitude modulation amount determined by the modulation means. apparatus. Speed detecting means for detecting the driving speed of the vibration type driving device;
Frequency control means for determining a drive frequency from the deviation between the speed signal obtained by the speed detection means and a given speed command value;
Modulation means for determining an amplitude modulation amount according to a predetermined parameter with respect to the driving speed of the vibration type driving device;
10. The control of the vibration type driving device according to claim 4, further comprising amplitude control means for independently performing amplitude modulation on each drive signal in accordance with the amplitude modulation amount determined by the modulation means. apparatus. Speed detecting means for detecting the driving speed of the vibration type driving device;
A frequency control means for determining a drive frequency from a deviation between a speed signal obtained from the speed detection means and a given speed command value, and outputting a pulse signal;
Modulation means for determining a phase modulation amount and a pulse width modulation amount in accordance with a predetermined parameter for the rotational speed of the vibration type driving device;
Phase control means for phase modulating the pulse signal in accordance with the phase modulation amount determined by the modulation means;
Pulse width control means for independently performing pulse width modulation on each of the pulse signals according to the pulse width modulation amount determined by the modulation means,
The drive signal is generated by a drive circuit configured by a switching element that outputs a power supply voltage in accordance with the phase-modulated and pulse-width-modulated pulse signal and a booster that boosts the power supply voltage. 8. A control device for a vibration type driving device according to 2 or 7. Speed detecting means for detecting the driving speed of the vibration type driving device;
A frequency control means for determining a drive frequency from a deviation between a speed signal obtained from the speed detection means and a given speed command value, and outputting a pulse signal;
Modulation means for determining a pulse width modulation amount according to a predetermined parameter for the rotational speed of the vibration type driving device;
Pulse width control means for pulse width modulating the pulse signal according to the pulse width modulation amount determined by the modulation means;
5. The plurality of drive signals are generated by a drive circuit configured by a switching element that outputs a power supply voltage according to the pulse signal subjected to the pulse width modulation and a boosting unit that boosts the power supply voltage. The control device for the vibration type drive device according to claim 9. A control device according to claims 1 to 15,
A vibration type driving device controlled by the control device;
And a driving mechanism driven by the vibration type driving device. A vibrating body having an elastic body and an electro-mechanical energy conversion element; and a contact body in contact with the vibrating body; applying a plurality of drive signals to the electro-mechanical energy conversion element; A control method of a vibration type driving device that excites a plurality of vibrations having the same shape and different positional phases, and causes the vibration body and the moving body to move relative to each other by a progressive vibration generated by combining these vibrations,
A vibration type drive characterized in that the drive signal is controlled such that the maximum displacement of the progressive vibration increases and decreases and the position where the maximum displacement becomes maximum changes in the relative movement direction of the vibration body and the moving body. Control method of the device. The method of controlling a vibration type driving apparatus according to claim 17, wherein the plurality of driving signals are periodically controlled with different temporal phases. The method of controlling a vibration type driving apparatus according to claim 17 or 18, wherein the amplitude and phase of the plurality of driving signals are periodically changed with different temporal phases. The method of controlling a vibration type driving device according to claim 17 or 18, wherein amplitudes of the plurality of driving signals are periodically changed with a temporal phase. 21. The control method of the vibration type drive device according to claim 17, wherein the drive signal is controlled to change a maximum displacement of the progressive vibration with respect to a change in frequency of the drive signal. . Speed detecting means for detecting the speed of the vibration type driving device;
21. The control of the vibration type driving device according to claim 17, wherein the drive signal is controlled so as to change a maximum displacement of the progressive vibration in accordance with a detection result of the speed detection means. Method. A vibrating body having an elastic body and an electro-mechanical energy conversion element; and a contact body in contact with the vibrating body; applying a plurality of drive signals to the electro-mechanical energy conversion element; A method of controlling a vibration type driving device that excites a plurality of vibrations having the same shape and different positional phases and relatively moves the vibrating body and the moving body by a progressive vibration generated by combining the vibrations,
A control method for a vibration type driving apparatus, wherein the driving signal is controlled so that the progressive vibration includes a vibration component that changes a positional phase of the progressive vibration. The method of controlling a vibration type driving device according to claim 23, wherein the amplitude and phase of the plurality of driving signals are periodically changed with a temporal phase. The method of controlling a vibration type driving device according to claim 23, wherein amplitudes of the plurality of driving signals are periodically changed with different temporal phases. 24. The method of controlling a vibration driving device according to claim 23, wherein a vibration component that changes a positional phase of the progressive vibration with respect to a change in the frequency of the driving signal is increased or decreased. 24. The control method of the vibration type driving device according to claim 23, wherein a vibration component that changes a positional phase of the progressive vibration is increased or decreased according to a speed of the vibration type driving device.

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