JP4208753B2 - Control device for vibration type drive device, control method for vibration type drive device, control program for vibration type drive device - Google Patents

Description

  The present invention relates to control of a so-called vibration type driving device that forms a progressive vibration in a vibrating body by an electro-mechanical energy conversion element and moves the vibrating body and a contact body relative to each other.

  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.

  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.

  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.

  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 supplied. When an AC voltage is supplied at a frequency near the natural frequency of the vibration mode to be excited, the elastic body resonates due to the bending moment applied to the elastic body due to the expansion and contraction of the piezoelectric element, and vibrations that are excited with respect to the AC voltages that differ by 90 °. The (mode) has the same shape and a different phase, and a progressive vibration wave (traveling wave) is formed by the synthesis.

  FIG. 44 shows a drive circuit for driving the vibration type drive device. This drive circuit is a drive circuit described in Patent Document 2, and a switching circuit constituted by MOSFETs 22 to 29 is turned on / off with a pulse generated by a pulse generation circuit (not shown), and has 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 °. Supply an AC voltage out of phase.

  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.

  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.

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.
JP 2001-157473 A JP 2002-176788 A JP-A-8-242593 JP-A-8-80073

  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.

  45A and 45B schematically show the contact / drive state between the vibrating body (elastic body) and the moving body.

  45A and 45B show the vibration displacement of the vibration body 101 and the response displacement of the moving body 106, and the protrusion shape and friction material on the vibration 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. 45A shows a high-speed driving with a large vibration amplitude, and FIG. 45B shows a vibration state at a low-speed driving with a small vibration amplitude than that in FIG. 45A. As shown in FIG. 45B, by reducing the vibration amplitude, the feed speed at each position is lowered and the speed is reduced (the speed is indicated by the length of the white arrow).

  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.

  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.

  As a method for reducing the speed while maintaining a certain vibration amplitude, the method is mainly used as a means for improving the response of vibration. For example, as proposed in Patent Document 4, switching to a standing wave at the time of stoppage is performed. There are a method, a method of changing the phase difference between the A phase and the B phase from 90 ° to change to a standing wave, or a method of reducing the vibration amplitude of one of the A phase and the B phase.

  However, such a method adversely affects the contact surface between the vibrating body and the moving body.

  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.

  FIG. 46 is a developed view schematically showing the vibration of the vibrating body, in which the time phase differs by 90 ° for each of A (+), B (+), A (−), and B (−) of the piezoelectric element 102. The state of vibration when the drive voltage is supplied is shown. 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.

  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.

  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.

  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.

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. A control device for a vibration-type drive device that supplies a drive signal to excite progressive vibration in the vibrating body and moves the vibrating body and the contact body relative to each other, and excites the first progressive vibration in the vibrating body. A first drive circuit that supplies a plurality of drive signals with different phases to the electromechanical energy conversion element, and a second progressive vibration different from the first progressive vibration is excited in the vibrating body. A second drive circuit for supplying the drive signal to the electromechanical energy conversion element, and a frequency control means for setting the frequency of the drive signal supplied by the first drive circuit and the frequency of the drive signal supplied by the second drive circuit. Have. The frequency circuit sets different frequencies for the drive signals supplied from the first drive circuit and the second drive circuit, and simultaneously excites the first progressive vibration and the second progressive vibration. To do.

The present invention also 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 supplies a plurality of drive signals to the electro-mechanical energy conversion element to vibrate. This is a control device for a vibration type drive device that excites progressive vibration in the body and relatively moves the vibration body and the contact body, and in order to excite progressive vibration in the vibration body, a plurality of drive signals having different phases are electrically A drive circuit that supplies the mechanical energy conversion element and a frequency control unit that controls the frequencies of the plurality of drive signals supplied by the drive circuit, the frequency control unit receiving a plurality of drive signals in the drive circuit; Is supplied to the electromechanical energy conversion element at a frequency of 1 to excite the first progressive vibration in the elastic body, and the frequency control means causes the drive circuit to generate a plurality of drive signals at the first frequency. Mechanical energy conversion element The supply is stopped, and a plurality of drive signals are supplied to the electromechanical energy conversion element at the second frequency while the damped vibration is generated by the first progressive vibration. The present invention is characterized in that two progressive vibrations are excited by being superimposed on a damped vibration .

The present invention also 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 supplies a plurality of drive signals to the electro-mechanical energy conversion element to vibrate. A method of controlling a vibration type driving device that excites a progressive vibration in a body and moves a vibrating body and a contact body relative to each other, and the first progressive vibration is excited in the vibration body. The step of setting the first frequency as the frequency of the plurality of drive signals to be supplied, and the second progressive vibration different from the first progressive vibration in the vibrator are supplied to the electro-mechanical energy conversion element. A step of setting a second frequency different from the first frequency as the frequency of the plurality of drive signals, and supplying a plurality of drive signals of the first frequency having different phases to the electromechanical energy conversion element, Different multiple Electrical drive signals of 2 frequencies - is supplied to the energy transducer, characterized by a step of exciting the first traveling vibration and a second traveling vibration simultaneously.

The present invention also 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 supplies a plurality of drive signals to the electro-mechanical energy conversion element to vibrate. A method of controlling a vibration type driving device that excites a progressive vibration in a body and moves a vibrating body and a contact body relative to each other, and the first progressive vibration is excited in the vibration body. The step of setting the first frequency as the frequency of the plurality of drive signals to be supplied, and the second progressive vibration different from the first progressive vibration in the vibrator are supplied to the electro-mechanical energy conversion element. By setting a second frequency different from the first frequency as the frequency of the plurality of drive signals, and supplying the plurality of drive signals to the electromechanical energy conversion element at the first frequency, the elastic body Excites the first progressive vibration And stopping supplying the plurality of drive signals to the electromechanical energy conversion element at the first frequency, and generating the plurality of drive signals while the damped vibration is generated by the first progressive vibration. Supplying the electro-mechanical energy conversion element at a second frequency to excite the elastic body by superimposing the second progressive vibration on the damped vibration .

Note that a control program for causing a computer to execute the above control methods is also included in the present invention.

  According to the present invention, when the vibration type driving device is driven at a low speed, it is possible to perform stable driving with less speed unevenness and to maintain stable performance of the vibration type driving device over a long period of time.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 12 shows the configuration of a traveling wave type vibration type driving apparatus that is Embodiment 1 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 21 such as various devices or devices using the vibration type drive device as a drive source via a gear (not shown). It operates in response to the output from 11.

  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. Other electro-mechanical energy conversion elements include electrostrictive elements and magnetostrictive elements.

  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.

  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.

  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 supplied with an approximately sinusoidal AC voltage whose time phase is different by 90 ° in order. When an alternating voltage is supplied 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 the 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.

  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 a drive signal (input signal) supplied to the piezoelectric element 2 through the pattern electrode. Further, FIG. 3 shows a description of the drive signal waveform.

  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.

  Here, in the case of four-phase driving for supplying a driving signal 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 examples below).

  The drive signals (A-phase drive voltage and B-phase drive voltage) shown in FIG. 2 are amplitude-modulated (standing wave) with the drive signal having the drive angular velocity ω shown in FIG. 3 as the fundamental wave (drive voltage V with a constant amplitude). Amplitude a) 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 is further generated on the A and B planes. A traveling wave that rotates the component is formed.

  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. 46, the vibration directions of the A and B phases are different in each part of the vibrating body.

  4A to 4D are schematic views showing the vibration mode of the present embodiment shown in FIG. 1 by dividing the vibration of each part of the vibrating body 1 into A phase and B phase components. FIG. 4A, FIG. It changes to the vibration state of FIG. 4B, FIG. 4C, and FIG. 4D. A solid line arrow is a vibration component of A phase, and a dotted line arrow is a vibration component of B phase.

  In the state of FIG. 4A. Since the A phase amplitude> the B phase amplitude, the vibration in the abdominal portion of the A phase is maximized, and the elliptical vibration is gradually rotated. In the state of FIG. 4B, the vibration amplitude is intermediate between the abdominal portion of the A phase and the B phase. Maximum. Furthermore, in the state of FIG. 4C, the vibration amplitude in the B-phase abdomen is maximized, and similarly returns to the vibration form of FIG. 4A through the state of FIG. 4D. 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.

  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.

  Here, FIG. 15 shows the vibration displacement of a normal (conventional) traveling wave in which the vibration amplitudes of the phases A and B are equal and the temporal phase is 90 ° when the vibration type driving device is driven at a constant speed. It represents a movement. 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.

  FIG. 16 shows the traveling wave when the vibration amplitude of the B phase is reduced as a conventional low-speed driving method described with reference to FIG. 46 when the vibration type driving device is driven at a constant speed. It represents the movement of vibration displacement. 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 has a substantially sine wave shape with a 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.

  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.

  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.

  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.

  On the other hand, FIG. 14 shows only the envelope excited by the vibrating body 1 by the driving method of the present embodiment when the vibration type driving device is driven at a constant speed. This figure shows the movement of the envelope connecting the maximum values of the vibration amplitude at each position of the traveling wave. 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 the present embodiment, the maximum value (maximum displacement) of the vibration displacement of the traveling wave increases and decreases, and the position where the maximum displacement becomes maximum moves sequentially or continuously.

  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.

  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 driving vibration component is only an elliptical component indicated by a broken line in FIGS. 4A to 4D, and the driving speed is also determined by the size of the broken elliptical line.

  According to the present embodiment, it is possible to drive at a lower speed while generating a vibration larger than the drive vibration component, and 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.

  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 the present embodiment, it is possible to average the rotation unevenness and the 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.

  As described above, in this 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.

  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 which is Embodiment 2 of the present invention. The driving method of the present embodiment is applied to the vibration type driving device described in the first embodiment. 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 moved sequentially.

  FIG. 6 shows drive signals (input signals) of this embodiment. FIG. 7 shows the drive amplitude of this embodiment on the time axis.

  In this embodiment, only independent amplitude modulation is applied to the A phase and the B phase.

  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.

  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.

  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 which is Embodiment 3 of the present invention. The driving method of the present embodiment is applied to the vibration type driving device described in the first embodiment. 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 moved sequentially.

  FIG. 9 shows changes in the amplitude of both phases A and B in the present example.

  In the present embodiment, as in the second embodiment, only the independent amplitude modulation is applied to the drive signals for both phases A and B, but the amplitude modulation for both phases A and B is not a single frequency. Is different. In this embodiment, there is a possibility that the feed speed changes due to the modulation and the rotation unevenness increases, but it is effective as a simpler driving method compared to the second embodiment.

  Furthermore, as shown in FIG. 10, the amplitude modulation may be stepped or rectangular.

  FIG. 11 shows the configuration of the control device of the vibration type drive device that is Embodiment 4 of the present invention.

  This control device is a control device that performs speed control of the vibration type drive device (vibration type drive device shown in FIG. 12) 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.

  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.

  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 supplied to the A-phase and B-phase piezoelectric elements of the vibration type driving device 110 through an amplifier circuit (not shown).

  In this embodiment, since the amount of amplitude / phase modulation is determined according to the driving speed of the vibration type driving device 110, the amount of modulation can be reduced when the driving speed is large and the amplitude is large. 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.

  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.

  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.

  The control device shown in FIG. 11 needs to be provided with an amplitude / phase modulation circuit 113 that can simultaneously calculate amplitude modulation and phase modulation of vibration, and loads on the control device are not small. Therefore, this embodiment intends to provide a control device that obtains the same effect as the control device shown in FIG. 11 with a circuit having a simpler configuration.

  FIG. 17 shows the configuration of the control device of the vibration type driving apparatus which is Embodiment 5 of the present invention.

  The configuration of the vibration type driving device 110 in this embodiment is the same as that shown in FIG. FIG. 19 shows an electrode pattern provided on the piezoelectric element 2 in this embodiment, and is a connection diagram showing a connection state between each electrode and first and second drive voltage generation circuits described later. The electrodes corresponding to A (+), B (+), A (−), and B (−) of the pattern electrodes of the piezoelectric element 2 provided in the vibration type driving device 110 are 131, 132, 133, and 134, respectively. The same drive signal is supplied for every third electrode.

  The control device in the present embodiment is a control device that performs speed control of the vibration type driving device 110, and includes speed information from a speed detector 117 such as an encoder provided in the vibration type driving device 110, and external (for example, vibration type driving device 110). The frequency phase control circuit 121 determines the frequency and phase of the drive signal according to the deviation from the speed command value given from the main control circuit of the operating device using the mold drive device 110 as a drive source.

  As each control parameter, an optimum frequency and phase with respect to the speed are stored in a memory (not shown) in advance, and a control parameter corresponding to the speed detected by the speed detector 117 is read from the memory and determined. Is done.

  The frequency command determined by the frequency phase control circuit 121 is input to the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123 as F1 and F2, and the phase command is input as P1 and P2, respectively. Further, the frequency phase control circuit 121 generates a first drive voltage by generating an ON / OFF command for controlling driving (ON command) and stopping (OFF command) of the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123, respectively. This is input to the circuit 122 and the second drive voltage generation circuit 123.

  Drive signals Φ11 and Φ12 corresponding to the frequency command F1 and the phase command P1 are supplied from the first drive voltage generation circuit 122 to the electrodes 131 and 132 of the piezoelectric element 2, and the frequency command F2 and the phase command are output from the second drive voltage generation circuit 123. Drive signals Φ21 and Φ22 corresponding to P2 are supplied to the electrodes 133 and 134 of the piezoelectric element 2.

  FIG. 18 shows drive waveforms of the drive signals Φ11, Φ12, Φ21, and Φ22. Φ12 has the same frequency as Φ11, and the temporal phase is delayed by 90 degrees with respect to Φ11. Φ22 has the same frequency as Φ21, and the temporal phase is advanced 90 degrees with respect to Φ21. The frequencies of Φ21 and Φ22 are set to values higher by several hundreds to several KHz than the frequencies of Φ11 and Φ12. Since the temporal phase shift of the drive signals Φ21 and Φ22 is opposite to the temporal phase shift of the drive signals Φ11 and Φ12, the traveling direction of the progressive vibration wave generated by the drive signals Φ11 and Φ12 and the drive signals Φ21, The traveling direction of the progressive vibration wave generated by Φ22 is reversed.

  Here, if six progressive vibration waves are rotated clockwise on the vibrating body 1 by the drive signals Φ11 and Φ12, six progressive vibrations are generated by the drive signals Φ21 and Φ22 as well as the traveling waves by Φ11 and Φ12. The wave rotates counterclockwise on the vibrating body 1.

  FIG. 20 shows characteristics of the frequency of the drive signal and the rotational speed of the moving body 6 when the temporal phase difference between the drive signals Φ11 and Φ12 is 90 degrees, and the temporal phase difference between the drive signals Φ21 and Φ22 is 90 degrees. The characteristics of the frequency of the driving signal and the rotational speed of the moving body 6 are shown. The vertical axis represents the rotational speed of the moving body 6, and the horizontal axis represents the frequencies of the drive signals Φ11, Φ12, Φ21, and Φ22. In this embodiment, the electrodes 131, 132, 133, and 134 are arranged at equal intervals, and the amplitudes (voltages) of the drive signals Φ11, Φ12, Φ21, and Φ22 are set to be equal. Oscillating waves and progressive oscillating waves due to Φ21 and Φ22 have substantially the same frequency characteristics.

  As shown in FIG. 20, the vibration type driving device 110 is driven and controlled in a frequency region higher than the resonance frequency fr, and has a characteristic that the rotation speed increases as the frequency of the drive signal is brought closer to the resonance frequency fr. Therefore, when the frequency F1 of the drive voltages Φ11 and Φ12 is made lower than the frequency F2 of the drive signals Φ21 and Φ22, the amplitude of the progressive vibration wave formed on the vibrating body 1 becomes larger when the amplitude is formed by the drive signals Φ11 and Φ12. . Therefore, the rotation by the progressive vibration wave formed by the drive signals Φ11 and Φ12 is larger than the rotation by the progressive vibration wave formed by the drive signals Φ21 and Φ22, and the rotation direction of the moving body 6 is the drive signal Φ11, Φ12. Is determined by the progressive vibration wave formed by

  Therefore, in this embodiment, since the progressive vibration wave formed by the drive signals Φ11 and Φ12 travels clockwise, it can be seen that the rotational direction of the moving body 6 is counterclockwise, which is the opposite direction. Although detailed description is omitted because it is publicly known, in the vibration wave driving device, the moving body travels in a direction opposite to the traveling direction of the progressive vibration wave. By synthesizing progressive vibration waves having different directions as described above, the vibration type driving device 110 can be driven at a lower speed than the conventional one without changing the amplitude of the drive voltage.

  Further, since the frequency of the progressive vibration wave formed by the drive signals Φ11 and Φ12 is different from the frequency of the progressive vibration wave formed by the drive signals Φ21 and Φ22, the vibration generated by the synthesis of these two progressive vibration waves. The position at which the maximum value (maximum displacement) of the displacement increases and decreases and the maximum displacement becomes maximum moves sequentially. Here, the progressive vibration wave is a vibration wave in which the wave rotates (travels) along the circumference of the ring-shaped vibrating body in the above example, but the vibration is generated by combining a plurality of excitation signals having different phases. It is a general term for vibration that forms elliptical vibration (circular vibration) in a part of the body. The synthesis of two progressive vibration waves referred to here is the synthesis (addition) of elliptical vibrations having different frequencies.

  In the fifth embodiment, two progressive vibration waves are synthesized, but three or more progressive vibration waves may be synthesized in order to vibrate at other vibration frequencies or other vibration modes. At that time, it is necessary to increase or decrease both the number of electrodes of the piezoelectric element 2 that supplies the drive signal and the number of drive voltage generation circuits according to the number of progressive vibration waves that are simultaneously generated. In the fifth embodiment, two progressive vibration waves in opposite directions are synthesized. However, when high-speed driving is specifically required according to the driving conditions, the driving signals Φ11, Φ12, and Φ21 are used. , .PHI.22 are sequentially shifted by 90 degrees and the frequencies are matched to generate a single progressive vibration wave similar to the conventional one to drive the vibration type driving device 110.

  FIG. 21 is a sixth embodiment of the present invention, and shows a configuration of a control device of a traveling wave type vibration type driving device when one progressive vibration wave is generated by a three-phase driving signal.

  FIG. 23 shows an electrode pattern provided on the piezoelectric element 2 and is a connection diagram showing a connection state between each electrode and first and second drive voltage generation circuits described later. In the piezoelectric element 2, electrodes 141, 142, 143, 144, 145, and 146 are repeatedly formed in order, and the same drive signal is supplied to every fifth electrode.

  The frequency command determined by the frequency phase control circuit 121 is input to the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123 as F1 and F2, and the phase command is input as P1 and P2, respectively. The frequency phase control circuit 121 generates ON / OFF commands for controlling the driving and stopping of the first driving voltage generation circuit 122 and the second driving voltage generation circuit 123, and generates the first driving voltage generation circuit 122 and the second driving voltage. Input to the circuit 123.

  Drive signals Φ11, Φ12, and Φ13 corresponding to the frequency command F1 and the phase command P1 are supplied from the first drive voltage generation circuit 122 to the electrodes 141, 142, and 143 of the piezoelectric element 2, and the frequency command is output from the second drive voltage generation circuit 123. Drive signals Φ21, Φ22, and Φ23 corresponding to F2 and the phase command P2 are supplied to the electrodes 144, 145, and 146 of the piezoelectric element 2.

  As shown in FIG. 22, Φ11, Φ12, and Φ13 have the same frequency, Φ12 has a temporal phase delayed by 120 degrees with respect to Φ11, and Φ13 has a temporal phase delayed by 120 degrees with respect to Φ12. Φ21, Φ22, and Φ23 have the same frequency, and Φ22 has a temporal phase advanced by 120 degrees with respect to Φ21, and Φ23 has a temporal phase advanced by 120 degrees with respect to Φ22. The frequencies of Φ21, Φ22, and Φ23 are set to values that are several hundreds to several KHz higher than the frequencies of Φ11, Φ12, and Φ13. By supplying the driving signals Φ11, Φ12, Φ13, Φ21, Φ22, and Φ23, two 8 traveling vibration waves having different traveling directions are formed in the vibrating body 1.

  Similar to the fifth embodiment, the rotation by the progressive vibration wave formed by the drive signals Φ11, Φ12, and Φ13 is larger than the rotation by the progressive vibration wave formed by the drive signals Φ21, Φ22, and Φ23, and the moving body 6 Is determined by the progressive vibration wave formed by the drive signals Φ11, Φ12, and Φ13.

  In the fifth embodiment and the sixth embodiment described above, an example in which electrodes are separately provided for each of a plurality of drive signals necessary for forming a plurality of progressive vibration waves has been described. Thus, the area of each electrode is reduced by the increase in the number, and in order to increase the amplitude of the progressive vibration wave, it is necessary to increase the voltage supplied to each electrode.

  Therefore, a method of supplying a plurality of drive signals to a common electrode can be considered. For example, there is a method of generating a drive voltage having two or more frequency commands and phase commands with a differential amplifier or the like and supplying the drive voltage to a common electrode.

  FIG. 24 shows the configuration of the control device for the vibration type driving device which is Embodiment 7 of the present invention for realizing the above configuration.

  In the piezoelectric element 2, electrodes 151 and 152 are repeatedly formed along the circumferential direction, and the same drive signal is supplied to every other electrode.

  The frequency command determined by the frequency phase control circuit 121 is input to the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123 as F1 and F2, and the phase command is input as P1 and P2, respectively. The frequency phase control circuit 121 generates ON / OFF commands for controlling the driving and stopping of the first driving voltage generation circuit 122 and the second driving voltage generation circuit 123, and generates the first driving voltage generation circuit 122 and the second driving voltage. Input to the circuit 123.

  The first drive voltage generation circuit 122 is connected to one end of the primary side of the transformer 161 and the transformer 162, and the second drive voltage generation circuit 123 is connected to the other end of the primary side of the transformer 161 and the transformer 162.

  Drive signals Φ11 and Φ12 corresponding to the frequency command F1 and the phase command P1 are supplied from the first drive voltage generation circuit 122 to one end on the primary side of the transformers 161 and 162, and the frequency command F2 and the phase are supplied from the second drive voltage generation circuit 123. Drive signals Φ21 and Φ22 corresponding to the command P2 are supplied to the other end on the primary side of the transformers 161 and 162.

  The transformer 161 and the transformer 162 form a differential amplifier. Drive signals having different frequencies and phases are input to the two primary terminals of the transformer 161 and the transformer 162, and a vibration wave that has been added and amplified is output to the secondary side. The inductance on the secondary side of the transformers 161 and 162 has a predetermined performance in the range where the parallel resonance frequency calculated with the capacitance of the piezoelectric element corresponding to the electrodes 151 and 152 is within the drive frequency usage range. It has been adjusted to be a value.

  FIG. 25 shows drive waveforms of the drive signals Φ11, Φ12, Φ21, and Φ22, the output voltage V1 on the secondary side of the transformer 161, and the output voltage V2 on the secondary side of the transformer 162.

  The drive signals Φ11, Φ12, Φ21, and Φ22 are pulse signals, and Φ12 has the same frequency as Φ11 and the temporal phase is delayed by 90 degrees with respect to Φ11. Φ22 has the same frequency as Φ21, and the temporal phase is advanced 90 degrees with respect to Φ21. The frequencies of Φ21 and Φ22 are set to values higher by several hundreds to several KHz than the frequencies of Φ11 and Φ12.

  When these signals are input to the primary side of the transformers 161 and 162, AM-modulated voltages V1 and V2 are output to the secondary side of the transformers 161 and 162. By supplying the output voltages V1 and V2 of the transformers 161 and 162 to the electrodes 151 and 152, the maximum value (maximum displacement) of the vibration displacement is increased or decreased on the surface of the vibrating body 1 as in the fifth embodiment, and A progressive vibration wave is formed in which the position where the maximum displacement is maximum moves sequentially. Thus, by generating a drive voltage having two or more frequency commands and phase commands with a differential amplifier or the like and supplying the drive voltage to a common electrode, a voltage lower than the configuration shown in the fifth or sixth embodiment is obtained. Thus, the vibration wave driving device 110 can be driven at a low speed.

  FIG. 26 shows a modification of the control device of FIG. This is a control device using inductor elements 171, 172, 173, and 174 instead of transformers 161 and 162. The inductor elements 171, 172, 173, and 174 are set such that the parallel resonance frequency calculated between their inductance and the capacitance of the piezoelectric element corresponding to the electrodes 151 and 152 has a predetermined relationship. . The inductor values of the inductor elements 171 and 172 connected to the drive signals Φ11 and Φ12 and the inductor elements 173 and 174 connected to the drive signals Φ21 and Φ22 may be different.

  In this embodiment, when an OFF command is output from the frequency phase control circuit 121, either or both of the outputs of the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123 are set in a floating state, Both need to be at the same potential.

  FIG. 27 shows a modification of the control device shown in FIG. 26, in which drive signals having different frequencies are supplied to the electrodes formed on both surfaces of the piezoelectric element 2. The output signals of the inductor elements 171 and 173 are connected to the electrodes 151a and 151b formed on both surfaces of one piezoelectric element, and the inductor elements 172 and 174 are connected to the electrodes 152a and 152b formed on both surfaces of the other piezoelectric element. ing. The control method of the vibration type driving device 110 is the same as that of the control device shown in FIG. When the vibration type driving device 110 is to be stopped quickly, it is necessary to stop the vibration type driving device 110 at the output voltage when the OFF command is input from the frequency phase control circuit 121 in order to quickly suppress the vibration of the vibrating body 1. is there.

  Next, a specific control method performed by the frequency phase control circuit 121 will be described with reference to a flowchart using the control device shown in FIG. 24 as an example.

  Forming two progressive vibration waves having opposite traveling directions on the vibrating body 1 at the same time has a concern that the driving efficiency is lower than when only one of the traveling vibration waves is formed on the vibrating body 1. However, when low-speed driving is realized by the conventional single progressive vibration wave, the contact area between the moving body 6 and the vibrating body 1 increases because the vibration amplitude of the vibrating body 1 is small as shown in FIG. The load on the vibrating body 1 increases due to the sliding friction between the vibrating body 1 and the moving body 6, and the efficiency is also lowered.

  Therefore, it is conceivable to cause the two progressive vibration waves to travel in opposite directions when the vibration type driving device 110 is driven at low speed, and to integrate the two progressive vibration waves into one when driving at high speed. Using actual speed, command speed, vibration amplitude of vibration body, frequency of drive signal, etc. as parameters, two traveling waves are integrated into one at or near the point where they cross a predetermined value. Some means is required. For example, when crossing this boundary, the output of one drive voltage generation circuit may be switched to the same waveform as the other.

  FIG. 28 shows a flowchart of the control device of the vibration type driving apparatus which is Embodiment 8 of the present invention.

  When the drive of the vibration type driving device 110 is started, an ON command is output to drive the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123 in step S101, the phase command P1 is 90 degrees, and the phase command P2 Is set to -90 degrees. Here, the phase command P1 sets a temporal phase shift of Φ12 with respect to Φ11, and the phase command P2 sets a temporal phase shift of Φ22 with respect to Φ21. In this case, the drive signal Φ12 has a temporal phase shift relative to Φ11. Therefore, the drive signal Φ22 is 90 degrees ahead of Φ21.

  In step S102, the speed command value Vs given from the outside is read out, and the current speed information Vr of the moving body 6 is detected.

  Next, in step S103, it is confirmed whether the speed command value Vs is 0. If it is not 0, the process proceeds to step S104, and if it is 0, the process proceeds to step S111.

  In step S104, the speed command value Vs is compared with a predetermined speed V0. If the speed command value Vs is less than or equal to the predetermined speed V0, the process proceeds to step S105, and if the speed command value Vs is greater than the predetermined speed V0, the process proceeds to step S106.

  In step S105, an ON command is output to drive the second drive voltage generation circuit 123, and the process proceeds to step S107. In this step, the speed command value Vs is equal to or lower than the predetermined speed V0, and the first drive voltage generation circuit 122 and the second drive voltage generation circuit are used to generate two progressive vibration waves having different traveling directions to perform low-speed driving. 123 is driven. If the second drive voltage generation circuit 123 is already in a drive state, this step is skipped.

  In step S106, an OFF command is output, the output of the second drive voltage generation circuit 123 is shorted to the ground, and the process proceeds to step S107. By short-circuiting the output of the second drive voltage generation circuit 123 to the ground, the frequency voltage formed only by the output voltage of the first drive voltage generation circuit 122 is supplied to the electrodes 151 and 152. In this step, the speed command value Vs is larger than the predetermined speed V0, and only the first driving voltage generation circuit 122 is driven to generate a single progressive vibration wave and perform high-speed driving. If the output of the second drive voltage generation circuit 123 has already been shorted to ground, this step is skipped.

  In step S107, the speed command value Vs is compared with the speed information Vr. If Vs is larger than Vr, the process proceeds to step S108, and if Vs is equal to or less than Vr, the process proceeds to step S109.

  In step S108, the frequency commands F1 and F2 are decreased by a predetermined frequency Fd to increase the moving speed of the moving body 6, and the process proceeds to step S102.

  If the speed command value Vs and the speed information Vr are equal in step S109, the frequency commands F1 and F2 are maintained and the process proceeds to step S102, and if not equal, the process proceeds to step S110.

  In step S110, the frequency commands F1 and F2 are increased by a predetermined frequency Fd to decrease the moving speed of the moving body 6, and the process proceeds to step S102.

Step S102 to step S108, step S109, or step S110 are repeated until the speed command value Vs becomes 0. When the speed command value Vs becomes 0, the process proceeds from step S103 to step S111.
In step S111, an OFF command is output to the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123, and the settings of the frequency commands F1 and F2 and the phase commands P1 and P2 are cancelled.

  In this embodiment, the second drive voltage generation circuit 123 is switched on / off in accordance with the value of the speed command value Vs from step S104 to step S106, but the value of the speed information Vr is used instead of the speed command value Vs. The second drive voltage generation circuit 123 may be turned on / off according to the above. Further, the second drive voltage generation circuit 123 may be turned ON / OFF according to the values of the frequency commands F1 and F2 set according to the comparison result between the speed command value Vs and the speed information Vr.

  In Example 8 above, the output of the second drive voltage generation circuit 123 is shorted to the ground in order to make one of the two progressive vibration waves zero, but the relationship between the drive signals Φ11 and Φ12 remains unchanged. Two progressive vibration waves traveling in the same direction with the drive signals Φ11 and Φ21 in the same phase and the drive signals Φ12 and Φ22 in the same phase are synthesized, or the relationship between the drive signals Φ11 and Φ12 is left as it is. In some cases, it is better to generate a single progressive vibration wave with Φ21 and Φ21 in opposite phases and the drive signals Φ12 and Φ22 as opposite phases.

  Further, when the output of the second drive voltage generation circuit 123 is shorted to the ground in order to set one amplitude of the two progressive vibration waves to 0, the progressive vibration wave that tries to drive the moving body 6 in the opposite direction. Since the amplitude changes abruptly, there is a possibility of giving an impact to the moving body 6.

  Therefore, it is necessary to control to gradually reduce the output of the second drive voltage generation circuit 123. As a simple method, it is conceivable that the amplitude of the output voltage of the second drive voltage generation circuit 123 is gradually reduced to short-circuit to the ground. Alternatively, the amplitude of the output voltage of the second drive voltage generation circuit 123 is used as a function of the output of the speed detector 117, the speed command value, the frequency of the drive signal, etc., so that the signal amplitude becomes smaller on the high speed side than the predetermined speed. It is conceivable to set by the setting means shown in the figure.

  FIG. 29A shows the relationship between the speed command and the amplitude of the output voltage, and FIG. 29B shows the relationship between the frequency command and the amplitude of the output voltage. FIG. 29A shows an example in which the amplitude PW of the output voltage of the second drive voltage generation circuit 123 changes according to the speed command, and FIG. 29B shows the relationship between the amplitude PW of the output voltage of the second drive voltage generation circuit 123 and the frequency command F2 of the drive signal. FIG.

  FIG. 30 shows the relationship between the frequency command and the phase command. In FIG. 30, when the value of the frequency command F1 determined by the frequency phase control circuit 121 is f0 or more that drives the moving body 6 at a predetermined speed V0 or less, the phase command P2 is set to −90 degrees, and the frequency phase control circuit 121 When the value of the determined frequency command F1 is less than f1 that drives the moving body 6 at a predetermined speed V1 or more, the phase command P2 is set to 90 degrees, and while the value of the frequency command F1 changes from f0 to f1, the frequency command F1 The phase command changes from −90 degrees to 90 degrees according to the change. FIG. 31 shows a flowchart of control of the vibration type driving device using the characteristics shown in FIG.

  When driving of the vibration type driving device 110 is started, an ON command is output to drive the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123 in step S201, the phase command P1 is 90 degrees, and the phase command P2 Is set to -90 degrees. Here, the phase command P1 sets a temporal phase shift of Φ12 with respect to Φ11, and the phase command P2 sets a temporal phase shift of Φ22 with respect to Φ21. In this case, the drive signal Φ12 has a temporal phase shift relative to Φ11. Therefore, the drive signal Φ22 is 90 degrees ahead of Φ21. Further, the frequency commands F1 and F2 are set to separate initial frequencies stored in advance in a memory or the like.

  Next, in step S202, the speed command value Vs given from the outside is read, and the current speed information Vr of the moving body 6 is detected.

  Next, in step S203, it is confirmed whether the speed command value Vs is 0. If it is not 0, the process proceeds to step S204, and if it is 0, the process proceeds to step S209.

  In step S204, the speed command value Vs is compared with the speed information Vr. If Vs is greater than Vr, the process proceeds to step S205, and if Vs is equal to or less than Vr, the process proceeds to step S206.

  In step S205, in order to increase the moving speed of the moving body 6, the frequency commands F1 and F2 are decreased by a predetermined frequency Fd, and the process proceeds to step S208.

  If the speed command value Vs and the speed information Vr are equal in step S206, the frequency commands F1 and F2 are maintained and the process proceeds to step S208. If not equal, the process proceeds to step S207.

  In step S207, the frequency commands F1 and F2 are increased by a predetermined frequency Fd to decrease the moving speed of the moving body 6, and the process proceeds to step S208.

  In step S208, the phase command P2 corresponding to the frequency command F1 is obtained using the function G, the frequency commands F1, F2, P1, and P2 are output, and the process proceeds to step S202. The function G is a value shown in FIG. 30, and may be a mathematical expression or a data table.

  Steps S202 to S208 are repeated until the speed command value Vs becomes 0. When the speed command value Vs becomes 0, the process proceeds from step S203 to step S209.

  In step S209, an OFF command is output to the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123, and the settings of the frequency commands F1 and F2 and the phase commands P1 and P2 are cancelled.

  According to this control method, when the speed command is higher than the predetermined speed, the phase difference between the output signals of the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123 is in the same direction, and the reduction in efficiency is suppressed. When the speed is lower than the predetermined speed, the phase difference between the output signals of the first drive voltage generation circuit 122 and the second drive voltage generation circuit 123 is in the reverse direction, so that stable driving can be achieved even at a low speed. In the above embodiment, the drive waveform addition processing is performed by a differential amplifier circuit or the like. However, the waveform data is digitally added and converted into an analog voltage by a D / A conversion circuit, and then amplified to a piezoelectric element. It may be a supply method. A known class D amplifier may be used as the amplifier circuit. However, it is considered that the switching period of the class D amplifier needs to be at least about 1/10 of the period of the highest frequency of the plurality of progressive vibration waves.

  FIG. 32 shows a control device for a vibration type driving apparatus which is Embodiment 10 of the present invention.

  The configuration of the vibration type driving device in this embodiment is the same as that shown in FIG. An electrode pattern in which electrodes are arranged in the order of A (+), B (+), A (−), and B (−) in the circumferential direction is formed on the piezoelectric element 2 provided in the vibration type driving device 110. The drive voltage generation circuit 124 supplies drive signals to these electrodes in accordance with the frequency command F1 and the phase command P1 of the frequency phase control circuit 121.

  FIG. 33 shows waveforms of A-phase and B-phase drive signals in the present embodiment. In the figure, the waveform shown by the solid line is the waveform of the A-phase drive signal, the waveform shown by the broken line is the waveform of the B-phase drive signal, and the waveform repeats the states 1 and 2 alternately. In state 1, the temporal phase of the A-phase drive signal is advanced 90 degrees from the B-phase drive signal, both frequencies are set to f1, and the duration is continued for t1. State 2 is a state in which the temporal phase of the A-phase drive signal is delayed by 90 degrees from the B-phase drive signal, both frequencies are set to f2, and continues for the time t2. The frequencies f1 and f2 are higher than the resonance frequency fr of the vibrator and further have a relationship of f1 ≦ f2.

  In addition, the states 1 and 2 are intermittently repeated, but the phases of the driving signals in the state 1 that are intermittently output are the same, and the same applies to the state 2. In state 1, a drive signal having a frequency f1 that generates a progressive vibration wave that rotates the moving body 6 in the counterclockwise direction is supplied to the piezoelectric element 2, and in state 2, a progressive vibration wave that rotates the moving body 6 in the clockwise direction. A drive signal having a frequency f 2 to be generated is supplied to the piezoelectric element 2.

  FIG. 34A shows the waveform of the driving signal only in state 1, and FIG. 34B shows the vibration displacement of the vibrating body. T1 which is the duration time of state 1 and t2 which is the duration time of state 2 are set to values at which the damped vibration of the vibration wave generated by the vibration at the other time does not disappear. By doing so, as shown in FIG. 34B, the forced vibration of the frequency f1 becomes t1 during t1, the forced vibration generated at t1 becomes the damping vibration of the resonance frequency fr during t2, and before this damped vibration disappears. Again, the vibration is forced at the frequency f1.

  FIG. 35A shows the waveform of the driving signal only in state 2, and FIG. 35B shows the vibration displacement of the vibrating body. As in the case of the state 1, as shown in FIG. 35B, the forced vibration of the frequency f2 becomes t2 during t2, the forced vibration generated at t2 becomes the damped vibration of the resonance frequency fr during t1, and this damped vibration disappears. Before starting, the vibration is again forced to the frequency f2.

  FIG. 36 and FIG. 37 show the response amplitude of the vibrating body when the driving signal is alternately in the state 1 and the state 2. In the figure, the black circles indicate the response amplitudes in the state 1 and the state 2, respectively.

  FIG. 36 shows the response amplitude of the vibrating body in the t1 section (state 1), which is attenuated from the forced vibration caused by the A-phase and B-phase drive signals having the frequency f1, and the forced vibration caused by the A-phase and B-phase drive signals having the frequency f2. The damped vibration of the frequency fr is superimposed.

  FIG. 37 shows the response amplitude of the vibrating body in the t2 section (state 2), which is attenuated from the forced vibration caused by the A phase and B phase drive signals having the frequency f2 and the forced vibration caused by the A phase and B phase drive signals having the frequency f1. The damped vibration having the frequency fr is superimposed.

  In this embodiment, each frequency is set so as to satisfy the relationship fr <f1 <f2 with respect to the resonance frequency fr of the vibrator. Therefore, as shown in FIG. 36 and FIG. The response amplitude of the forced vibration due to the frequency f1 is larger than the response amplitude of the damped vibration after the forced vibration due to the frequency 2, and in the state 2, the response amplitude of the damped vibration after the forced vibration due to the frequency f1 is due to the frequency 2 It becomes larger than the response amplitude of forced vibration. Therefore, the movable body 6 is rotated counterclockwise in both the state 1 and the state 2.

  FIG. 38 shows the vibration displacement of the vibrating body when the state 1 and the state 2 are alternately repeated. The response amplitude due to the vibration of the A-phase drive signal and the B-phase drive signal is modulated with the amplitude and phase modulated in the period of 1 / (f2-fr) and 1 / (f1-fr) as shown in the figure. It becomes a waveform.

  FIG. 39 shows the vibration trajectory of the vibration wave having the modulation waveform shown in FIG. 38, which is shown on the AB plane with the horizontal and vertical axes representing the vibration displacement of the A phase and the B phase. According to the present embodiment, a vibration locus similar to that shown in FIG. 1 can be obtained.

  FIG. 40 shows the relationship between the frequency of the drive signal and the response amplitude of the vibrating body in the control device for the vibration type drive device that is Embodiment 11 of the present invention.

  In the present embodiment, the drive speed of the moving body is changed by increasing or decreasing the frequency of the drive signal while maintaining the frequency difference Δf between the drive signals of the state 1 and the state 2 that are alternately vibrated.

  In the figure, f1 and f2 and f1 ′ and f2 ′ indicate the frequency of the drive signal on the high-speed drive side and the low-speed drive side, respectively, and the response amplitude of the vibrating body decreases as the frequency increases from the resonance frequency. The difference between the response amplitude of the vibrating body in state 1 and the response amplitude of the vibrating body in state 2 is reduced.

  The smaller the difference between the response amplitudes of the two vibrations synthesized, the smaller the short-axis amplitude of the elliptical trajectory formed by the response amplitudes of the A-phase and B-phase drive signals, so that the amplitude of the contact portion is greatly reduced. In addition, the driving speed on the contact surface can be reduced. The driving method of this embodiment is effective at low speed driving where the vibrator and the moving body are in contact with the entire surface, and is driven by a single progressive vibration wave at normal driving speed, and is applied to this embodiment at low speed driving. Switch to the drive shown.

  FIG. 41 shows the relationship between the frequency of the drive signal and the response amplitude of the vibrator in the control device for the vibration type drive device that is Embodiment 12 of the present invention.

  In this embodiment, the frequency f1 of the A phase and B phase drive signals in the state 1 is fixed, and the drive speed is changed by changing the frequency f2 of the A phase and B phase drive signals in the state 2.

  Decreasing the feed rate of the moving body 6 by increasing the response amplitude of forced vibration and damped vibration in state 2 by setting the frequency of the A-phase and B-phase drive signals in state 2 to f2 ′ lower than f2. Can do. Furthermore, by making f2 coincide with f1, the trajectory on the AB plane becomes a line and the feed speed becomes 0, and the reversing operation can be performed by setting f2 to a value smaller than f1.

  FIG. 42 shows waveforms of A-phase and B-phase drive signals in the thirteenth embodiment.

  In this embodiment, a frequency time control circuit is provided in place of the frequency phase control circuit, and the speed is made variable by changing the ratio of t1 and t2, which are the duration times of states 1 and 2.

  By making the duration t1 of state 1 longer than the duration t2 of state 2, the vibration energy of the forced vibration of frequency f1 can be made sufficiently large. Further, since the period of t2 is relatively short with respect to the period of t1, the attenuation amount of the damped vibration after the forced vibration of the frequency f1 in the state 2 is switched to the next forced vibration while the attenuation amount is small. And the short axis of the elliptical locus formed on the contact surface of the vibrating body with the moving body can be increased to increase the driving speed.

  In this way, the driving speed can be changed by manipulating the duration t1 of state 1 and the duration t2 of state 2 in accordance with the driving speed of the vibration type driving device 110. By reducing t2 and changing it to 0, it is possible to continuously change from low-speed driving to driving by a single progressive vibration wave, so from the time of low-speed driving where the vibrating body and the moving body are in full contact, It is possible to change the speed in a wide range up to the normal speed at which the vibrating body and the moving body partially contact each other. Further, the inversion operation can be performed by setting t2 larger than t1 and setting the frequency f2 larger than f1.

  FIG. 43A shows the output waveform of the monitor circuit in the fourteenth embodiment, and FIG. 43B shows the drive signal waveform in the fourteenth embodiment.

  During the period t2 during which the forced vibration in the state 1 is stopped and oscillated as a damped vibration, the period of the free vibration of the vibrator and the moving element becomes a period, so the phase between the state 1 to be supplied next changes. . Since the phase of the damped vibration and the next state 1 deviate from the response phase of the forced vibration in state 1, efficient excitation is not possible. Therefore, in this embodiment, a circuit for monitoring the vibration displacement or distortion of the vibrating body is provided, and the excitation phase is made variable so that the vibration is oscillated at a predetermined phase with respect to the damped vibration when the supply of the drive signal is started. . Sa and Sb in FIG. 43A are signals obtained from the monitor circuit. At the start of the next state 1, the phase of the vibration signal at the time of forced vibration or the phase of the drive signal so as to be a predetermined phase determined in advance. Therefore, the excitation force works efficiently at the start of forced vibration.

  Note that the configurations of the control devices described in the above embodiments are merely examples, and control the drive signal so that the maximum position of the maximum displacement of the traveling wave formed on the vibrating body 1 is sequentially moved. Any configuration may be used.

Further, in the above embodiments, the case where the drive signal is controlled by hardware has been described, but it is also possible to cause the computer to execute similar control by a computer program ( control program) . The present invention can also be applied to a storage medium readable by an information processing apparatus that stores this program.

  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.

The figure which shows the vibration locus | trajectory of the vibrating body in the vibration type drive device controlled by the control apparatus which is Example 1 of this invention. FIG. 2 is a diagram illustrating drive signal waveforms in the first embodiment. FIG. 4 is a diagram illustrating a driving signal waveform formula in the first embodiment. FIG. 3 is a schematic diagram illustrating vibration of a vibrating body according to the first embodiment. FIG. 3 is a schematic diagram illustrating vibration of a vibrating body according to the first embodiment. FIG. 3 is a schematic diagram illustrating vibration of a vibrating body according to the first embodiment. FIG. 3 is a schematic diagram illustrating vibration of a vibrating body according to the first embodiment. The figure which shows the vibration locus | trajectory of the vibrating body in the vibration type drive device controlled by the control apparatus which is Example 2 of this invention. FIG. 10 is a diagram illustrating a driving signal waveform formula in the second embodiment. FIG. 9 is a chart showing drive amplitude in the second embodiment. The figure which shows the vibration locus | trajectory of the vibrating body in the vibration type drive device controlled by the control apparatus which is Example 3 of this invention. FIG. 9 is a chart showing drive amplitude in the third embodiment. FIG. 9 is a chart showing drive amplitude in the third embodiment. The block diagram which shows the structure of the control apparatus which is Example 4 of this invention. Sectional drawing which shows the structure of the traveling wave type vibration type drive device of each Example. The perspective view of the vibrating body used for the said vibration type drive device. The figure showing the motion of the envelope of the vibration displacement of the traveling wave excited by the control apparatus of Example 1. FIG. The figure showing the motion of the vibration displacement of the traveling wave excited by the conventional control method. The figure showing the motion of the vibration displacement of the traveling wave excited by the conventional control method. The block diagram which shows the structure of the control apparatus which is Example 5 of this invention. FIG. 10 is a diagram showing drive signal waveforms in the fifth embodiment. FIG. 10 is a diagram showing an electrode pattern and electrode wiring of a piezoelectric element in Example 5. The figure which shows the frequency-speed characteristic of a vibration type drive device. The block diagram which shows the structure of the control apparatus which is Example 6 of this invention. FIG. 10 is a diagram showing drive signal waveforms in the sixth embodiment. The figure which shows the electrode pattern and electrode wiring of the piezoelectric element in Example 6. FIG. The block diagram which shows the structure of the control apparatus which is Example 7 of this invention. The figure which shows the drive signal waveform in Example 7, and the output signal waveform of a transformer secondary side. The block diagram which shows the structure of the modification of the control apparatus shown in FIG. The block diagram which shows the structure of another modification of the control apparatus shown in FIG. The figure which shows the control flowchart which is Example 8 of this invention. The figure which shows the characteristic of the voltage amplitude of the speed instruction | command in one Embodiment 9, and one drive voltage generation circuit. The figure which shows the characteristic of the voltage command of Example 9 and the voltage amplitude of one drive voltage generation circuit. The figure which shows the characteristic of the frequency command in Example 9, and the phase command of one drive voltage generation circuit. The figure which shows the control flowchart which is Example 9. FIG. FIG. 10 is a block diagram showing the configuration of a control apparatus that is Embodiment 10 of the present invention. FIG. 18 shows drive signal waveforms in the tenth embodiment. The figure which shows the drive signal waveform of only the state 1 in Example 10. FIG. The figure which shows the response amplitude only in the state 1 in Example 10. FIG. The figure which shows the drive signal waveform of only the state 2 in Example 10. FIG. The figure which shows the response amplitude only in the state 2 in Example 10. FIG. The figure which shows the response amplitude of the forced vibration of the state 1 in Example 10, and a damped vibration. The figure which shows the response amplitude of the forced vibration of the state 2 in Example 10, and a damped vibration. FIG. 10 is a diagram showing response amplitude in Example 10. FIG. 18 is a diagram illustrating a vibration locus of a vibrating body in a vibration type driving device controlled by a control device that is Embodiment 10. The figure which shows the response amplitude of the forced vibration of the state 1 in Example 11, and a damped vibration. The figure which shows the response amplitude of the forced vibration of the state 1 in Example 12, and a damped vibration. FIG. 18 shows drive signal waveforms in the thirteenth embodiment. FIG. 18 is a diagram showing an output waveform of a monitor circuit in Example 14; The figure which shows the drive signal waveform in Example 14. FIG. The figure which shows the structure of the drive circuit of the conventional vibration type drive device. FIG. 6 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. 6 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. The schematic diagram which shows the vibration of the vibrating body in the conventional vibration type drive device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vibrating body 1A Elastic body 2 Piezoelectric element 4 Comb-like protrusion 5 Friction material 6 Moving body 8 Pressurizing spring 9 Disc 10 Housing

Claims (9)

A vibration body having an elastic body and an electro-mechanical energy conversion element; and a contact body in contact with the vibration body, and a plurality of drive signals are supplied to the electro-mechanical energy conversion element to travel to the vibration body A control device for a vibration-type driving device that excites sexual vibration and relatively moves the vibrating body and the contact body,
  A first drive circuit for supplying a plurality of drive signals having different phases to the electromechanical energy conversion element to excite a first progressive vibration in the vibrator;
  A second drive circuit for supplying a plurality of drive signals having different phases to the electro-mechanical energy conversion element in order to excite the second progressive vibration different from the first progressive vibration in the vibrating body;
  Frequency control means for setting the frequency of the drive signal supplied by the first drive circuit and the frequency of the drive signal supplied by the second drive circuit;
  The frequency control means sets different frequencies for the drive signals supplied from the first drive circuit and the second drive circuit, and simultaneously excites the first progressive vibration and the second progressive vibration. A control device for a vibration type drive device. The phase difference between the plurality of drive signals is set so that the first driving circuit and the second driving circuit have different traveling directions of the first progressive vibration and the second progressive vibration. Item 2. A control device for a vibration type driving device according to Item 1. Speed detecting means for detecting the driving speed of the vibration type driving device;
  The frequency control means determines drive frequencies of the first progressive vibration and the second progressive vibration from a deviation between the speed information obtained by the speed detection means and a given speed command value. The control device of the vibration type driving device according to claim 2. Phase control means for determining a temporal phase difference between the plurality of drive signals supplied from the first drive circuit and a temporal phase difference between the plurality of drive signals supplied from the second drive circuit from the speed command value. The control device of the vibration type driving device according to claim 3. A vibration body having an elastic body and an electro-mechanical energy conversion element; and a contact body in contact with the vibration body, and a plurality of drive signals are supplied to the electro-mechanical energy conversion element to travel to the vibration body A control device for a vibration-type driving device that excites sexual vibration and relatively moves the vibrating body and the contact body,
  A drive circuit for supplying a plurality of drive signals having different phases to the electromechanical energy conversion element in order to excite progressive vibration in the vibrating body;
Frequency control means for controlling the frequency of the plurality of drive signals supplied by the drive circuit;
The frequency control means excites the first progressive vibration in the elastic body by causing the drive circuit to supply the plurality of drive signals to the electromechanical energy conversion element at a first frequency,
The frequency control means stops the drive circuit from supplying the plurality of drive signals to the electro-mechanical energy conversion element at a first frequency, and a damped vibration is generated by the first progressive vibration. During this time, the plurality of drive signals are supplied to the electro-mechanical energy conversion element at a second frequency to excite the elastic body with the second progressive vibration superimposed on the damped vibration. A control device for a vibration type driving device. Speed detecting means for detecting the driving speed of the vibration type driving device;
  The frequency control means determines, from the speed information obtained by the speed detection means, a duration for which each of the drive signals of the first frequency and the second frequency is supplied to the electromechanical energy conversion element. The control device of the vibration type driving device according to claim 5. 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 drive signals are supplied to the electro-mechanical energy conversion element to travel to the vibrating body A method of controlling a vibration type driving device that excites natural vibration and relatively moves the vibrating body and the contact body,
  Setting a first frequency as frequencies of a plurality of drive signals supplied to the electro-mechanical energy conversion element to excite a first progressive vibration in the vibrating body;
  In order to excite the second progressive vibration different from the first progressive vibration in the vibrating body, a second frequency different from the first frequency as the frequency of the plurality of drive signals supplied to the electro-mechanical energy conversion element Setting the frequency of
  Supplying a plurality of first-frequency drive signals having different phases to the electro-mechanical energy conversion element, and supplying a plurality of second-frequency drive signals having different phases to the electro-mechanical energy conversion element; A control method for a vibration type driving apparatus, comprising the step of simultaneously exciting the first progressive vibration and the second progressive vibration. A vibration body having an elastic body and an electro-mechanical energy conversion element; and a contact body in contact with the vibration body, and a plurality of drive signals are supplied to the electro-mechanical energy conversion element to travel to the vibration body A control method of a vibration type driving device that excites sexual vibration and relatively moves the vibrating body and the contact body,
  Setting a first frequency as frequencies of a plurality of drive signals supplied to the electro-mechanical energy conversion element to excite a first progressive vibration in the vibrating body;
  In order to excite the second progressive vibration different from the first progressive vibration in the vibrating body, a second frequency different from the first frequency as the frequency of the plurality of drive signals supplied to the electro-mechanical energy conversion element Setting the frequency of
Supplying the plurality of drive signals to the electromechanical energy conversion element at the first frequency to excite a first progressive vibration in the elastic body;
The supply of the plurality of drive signals to the electro-mechanical energy conversion element at the first frequency is stopped, and the plurality of drive signals are generated while the damped vibration is generated by the first progressive vibration. Supplying the electro-mechanical energy conversion element with the second frequency to excite the elastic body with the second progressive vibration superimposed on the damped vibration. Control method of vibration type driving device.   A control program for a vibration type driving apparatus, characterized by being a program for causing a computer to execute the control method according to claim 7 or 8.

Images