JP3315525B2 - Vibration drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a vibration driven equipment typified by the vibration wave motor, efficiently relates to a vibration drive equipment which drives can be performed in particular by the battery power source.

[0002]

2. Description of the Related Art As a typical example of a vibration device, a vibration wave motor is known, which is formed by, for example, forming a ring-shaped vibration elastic body such as a metal on a piezoelectric element (electrostriction) as an electromechanical energy conversion element. Element) is used as a vibrator,
A contact body that forms a vibration wave (progressive vibration wave) in an out-of-plane vibration mode on the surface of the vibration elastic body by applying a two-phase frequency voltage having a different phase to the piezoelectric element and presses and contacts the surface. And the vibrator are relatively moved.

As a drive control of the relative movement between the vibrator and the contact body, there is known a drive control system for adjusting a relative speed by changing a frequency of a frequency voltage applied to a piezoelectric element. Is to make the resonance frequency the fastest and to perform drive control using a frequency region higher than this frequency. Therefore, the control is to increase the speed as the frequency is lowered.

When setting the relative speed to a desired speed, a frequency corresponding to the desired speed is selected and a frequency voltage is applied to the piezoelectric element. Rotation starts.

Here, the correspondence between speed and frequency is affected by environmental conditions such as power supply voltage and temperature. As for the power supply voltage, the voltage fluctuation can be avoided by converting the battery voltage to a constant voltage using a DC / DC converter or the like, but there is a disadvantage that the speed varies due to other environmental conditions.

Therefore, in order to smoothly rotate the vibration wave motor and to drive the vibration wave motor at a stable speed with respect to a slight change in environmental conditions, the driving frequency is gradually increased from a high frequency when starting the vibration wave motor. After it is confirmed that the motor has started, the actual rotation speed is compared with the desired rotation speed, and if the actual rotation speed is higher than the desired rotation speed, the frequency is shifted to the higher frequency direction. If the actual rotation speed is lower than the desired rotation speed, the frequency may be shifted to a lower frequency direction and the frequency may be controlled so as to obtain the desired speed.

At this time, the high frequency at the time of starting is set to a frequency at which the vibration wave motor actually starts to rotate, and if the frequency is gradually decreased from this set frequency, the vibration wave motor is shortened to a desired speed. Although it can be driven smoothly in time, the characteristics of the vibration wave motor are not constant and are affected by environmental changes such as temperature.If the frequency at the start of startup is fixed, it will not be possible to respond to changes in temperature etc. However, there is a possibility that the time until the start of the start becomes long, or the start of the rotation suddenly occurs, and in the worst case, the start cannot be started.

As a method for solving the above problem, the following method has been proposed. In other words, the control method is such that the starting frequency at the time of the previous driving is stored, and at the next driving, scanning is performed from the stored frequency to a lower frequency. In this method, the driving start frequency is memorized by utilizing the past record of driving, and the frequency scanning method at the next driving is used as a reference.

After the vibration wave motor can be started, it is necessary to perform speed control for bringing the rotation speed of the motor closer to a desired rotation speed.

In the speed control, the rotation speed of the vibration wave motor is detected at a certain cycle, the obtained rotation speed is compared with a desired rotation speed, and when the actual rotation speed is higher than the desired rotation speed, the frequency is controlled. Is increased by a predetermined value, and when the actual rotation speed is lower than a desired rotation speed, the frequency is reduced by a predetermined value. By changing the cycle of detecting the rotation speed of the vibration wave motor, the control can be speeded up or slowed down according to the response speed of the vibration wave motor. As for the width of increasing or decreasing the frequency, there are a uniform method and a method of changing the frequency according to a ratio of an actual rotation speed to a desired rotation speed.

By the way, the driving voltage of the conventional vibration wave motor is such that the battery voltage is boosted and made constant by a DC / DC converter or the like, and the voltage is further boosted by a matching coil and applied.

However, in recent years, the drive voltage of the vibration wave motor has been reduced, and the vibration wave motor which can be driven by the battery voltage has come to a practical stage. When driving such a vibration wave motor, the relationship between the number of revolutions of the vibration wave motor and the power supply frequency (fN characteristic) changes due to fluctuations in the battery voltage.
This is shown in FIG. In the figure, the power supply voltage is 3 V
In this case, the motor starts rotating at the frequency Fbtr, and the number of rotations increases by gradually decreasing the frequency from the frequency Fbtr. When the power supply voltage is 6 V, rotation is possible at the settable maximum frequency Fmax, and the number of rotations for the same frequency is higher than that at 3 V. In addition, the inclination of the change in the number of rotations with respect to the change in the frequency tends to decrease when the voltage is high, and to increase when the voltage is low.

However, in the above-mentioned conventional example, if a uniform frequency change rate is set regardless of the battery voltage when the motor is accelerated or decelerated, there arises a problem that it is impossible to cope with the battery voltage fluctuation. As described above, the f-
The N characteristic indicates that the inclination is small when the voltage is high and the inclination is large when the voltage is low. Therefore, if the optimal acceleration is set when the voltage is high, the acceleration is too fast to start when the voltage is low, and conversely, if the optimal acceleration is set when the voltage is low, the acceleration is slow and takes time at high temperatures. I was Regarding the deceleration, when the voltage is high, the optimal deceleration is set, and when the voltage is low, it is easy to stop, so it takes time to decelerate. Conversely, when the voltage is low, the optimal deceleration is set at a high temperature. There has been a problem that overrunning occurs without being able to decelerate.

The present invention has been made in view of the above matters ,
Shortening the drive movement time, stabilization of the rotation, making it possible to realize improvement of stopping accuracy, further not necessary to use a constant voltage means, such as DC / DC converter, the configuration is simple,
And it is intended to St. provide a low cost vibration driving equipment of.

[0015]

Means and operation for solving the problems] The invention described in claim 1, a frequency voltage transducer electrical - and frequency voltage supplying means for applying the mechanical energy conversion element, and is outputted from the peripheral wave voltage supplying means Decrease the frequency of the frequency voltage during acceleration
In the vibration drive device that performs the acceleration operation, the frequency of the frequency reduction operation in the acceleration operation or the execution frequency of the frequency reduction operation is set to the reduction width or the frequency according to the frequency voltage value. I do. Claim 2
Invention converts the frequency voltage into the electro-mechanical energy
Frequency voltage supply means applied to the switching element, and the frequency voltage supply means
The frequency of the frequency voltage output from the means is increased during deceleration.
So, in the vibration driving apparatus which performs deceleration, the deceleration movement
Increase or frequency increase in frequency increase operation
Increase frequency of the addition operation according to the frequency voltage value or
The frequency is set.

According to the first and second aspects of the present invention , the acceleration and deceleration at the time of starting and stopping can be controlled at optimum values without being affected by fluctuations in the voltage value.

[0017]

[0018]

FIG. 1 is a block diagram showing a first embodiment of the present invention, in which an A / D converter is used as a means for detecting a battery voltage.

In FIG. 1, reference numeral 1 denotes a microcomputer, and 2 denotes a D / A.
A digital output signal (D /
Aout) to an output voltage. Reference numeral 3 denotes a voltage controlled oscillator (VCO) which outputs a frequency voltage corresponding to the output voltage of the D / A converter 2. 4 is a frequency divider / phase shifter.
The frequency voltage of the VCO 3 is divided to output a rectangular wave having a phase difference of π / 2. Reference numerals 5 and 6 denote power amplifiers which amplify the frequency voltage of the frequency divider / phase shifter 4 to a voltage and a current value that can drive the vibration wave motor 9 by the battery 15. Reference numerals 7 and 8 denote matching coils.

9 is a vibration wave motor, 9a is a rotor which is a contact body, 9b is a stator which is a vibrator, and 10 is a pulse plate, which has a plurality of slits formed in a radial direction as shown in FIG. It is coaxial with the output shaft of the vibration wave motor 9 and rotates together with the rotor 9a of the vibration wave motor 9. 1
An interrupter 1 optically detects the rotation of the pulse plate 10. A signal detection circuit 12 of the interrupter 11 amplifies a small signal of the interrupter 11 and converts it into a digital signal. 13 is an up / down counter,
The pulse signal generated by the rotation of the pulse plate 10 is counted.

Reference numeral 14 denotes a memory circuit which stores a drive processing program for the vibration wave motor, speed table data for driving the vibration wave motor, and the like. 15 is a battery, 16
Is an A / D converter, which A / D converts the voltage of the battery 15 and outputs it. In this embodiment, it is assumed that the A / D converter 16 has 8 bits and the full scale is 7V. Next, each terminal of the microcomputer 1 will be described.

DIR1 is an output terminal for instructing the counting direction of the up / down counter 13. For convenience of explanation, "H" is up and "L" is down. PULSE
IN is an input terminal for the count value of the up / down counter 13. MON is a direct monitor input terminal for the output of the detection circuit 12. RESET is a reset output terminal of the up / down counter 13 and is reset by "H". C
NT EN / $ DIS is an output terminal for the count enable / disable instruction of the up / down counter 13, which is enabled by "H" and disabled by "L". D / Aout is an output terminal to the D / A converter 2.

DIR2 is a frequency voltage A, B applied to the vibration wave motor 9 for switching the rotation direction of the vibration wave motor 9.
Is an output terminal for giving to the frequency divider / phase shifter 4 an instruction to change the phase difference between 90 ° and 270 °. USM
EN / ￣DIS turns ON / OFF the output of frequency divider / phase shifter 4
This terminal is used to turn ON when “H” and OFF when “L”.
And A / Din is an input terminal from the A / D converter 16. ADDRESS is an output terminal for specifying an address of the memory circuit 14, and specifies which data is to be input. DATA IN is ADDRESS
This is an input terminal for data stored at an address on the memory circuit 14 specified by output to the terminal.

Next, the vibration wave motor 9 will be described with reference to FIG.

FIG. 2 is an explanatory view showing the arrangement of piezoelectric (electrostrictive) elements, which are electric-mechanical energy conversion elements, arranged on the back surface of the stator 9b. A ₁ and B _{1 in} FIG.
The stator 9b
It is a 1st and 2nd electrostrictive element group arrange | positioned at the top. Also, S
₁ is a electrostrictive element for the sensor that is disposed at a position offset is the first 45 ° phase with respect to the electrostrictive element group B _1. Each of these electrostrictive elements may be individually attached to the vibrator, or may be integrally formed by a polarization process.

[0026] Returning to Figure 1, A, B, S respectively indicate the first, second driving electrodes and the sensor electrodes for electrostrictive element groups and the sensor electrostrictive element S _1, the amplifier to the electrode A 5 is applied, and
When a frequency voltage is applied to the electrode B via the amplifier 6, an out-of-plane mode progressive vibration wave is formed on the back surface of the stator 9b. Further, when the vibration wave is formed on the vibrating body, the sensor electrostrictive element S in accordance with the state of the vibration wave outputs an output (frequency voltage), at the sensor electrode S _1, which is detected. In the resonance state, the vibration wave motor has a characteristic that the phase relationship between the drive voltage to the A electrode and the output voltage from the sensor electrode indicates a specific relationship,
First electrostrictive element group A ₁ to which a frequency signal is applied at electrode A
In the case of the present embodiment, when the phase of the signal waveform between the electrodes A and S is shifted by 135 ° in the normal rotation state, the resonance state is indicated. At the time of reverse rotation, it is assumed that a resonance state is exhibited when the phase shifts by 45 °, and that the above-mentioned phase relationship shifts as the distance from the resonance deviates.

FIGS. 3 and 4 are flowcharts showing a program flow executed by the microcomputer 1 of FIG. 1. The microcomputer 1 executes a control operation according to the program flow. Note that the step numbers of the respective operations are given in square frames.

Next, the operation of the embodiment shown in FIG. 1 will be described with reference to this flowchart.

When entering the vibration wave motor drive processing routine,
First, step 1 is performed. Hereinafter, the operation of each step will be described.

[Step 1] The initial value of the up / down counter 13 is input from the PULSE IN terminal and stored in the variable FPC _OLD .

[Step 2] The value of the variable FMAX is transferred to the variable FREQ. Note that FMAX is an initial frequency determined based on the driving frequency at the time of the previous drive, and the frequency at which it was confirmed that the motor started to move when the motor was stopped normally the previous time, and 0 when the motor was stopped in the non-driveable state. Is stored. The values actually output to the D / Aout terminal are directly stored as these variables FMAX and FREQ, and the smaller the value, the higher the drive frequency.

[Step 3] The value of FREQ set in step 2 is output to the D / Aout terminal. As a result, the D / A converter 2 converts the digital voltage value output from the D / Aout terminal into an analog voltage, and
Output to The VCO 3 converts the voltage output from the D / A converter 2 into a frequency and outputs the frequency to the frequency divider / phase shifter 4.

[Step 4] The drive rotation direction is determined.
The process proceeds to step 5 in the case of normal rotation, and proceeds to step 6 in the case of reverse rotation.

[Step 5] Since the driving rotation direction is normal rotation, "H" is output to the DIR1 terminal to up / down.
The count direction of the n counter 13 is set to the up direction. Also, “H” is output to the DIR2 terminal to set the phase difference between the signals A and B output from the frequency divider / phase shifter 4 to 90 °,
Proceed to step 7.

[Step 6] Since the driving rotation direction is reverse, "L" is output to the DIR1 terminal and up / down is performed.
The count direction of the n counter 13 is set to the down direction. Also, “L” is output to the DIR2 terminal to set the phase difference between the signals A and B output from the frequency divider / phase shifter 4 to 270 °.

[Step 7] CNT EN / $ DIS
"H" is output to the terminal, and the up / down counter 13 is set to the count enable state.

[Step 8] USM EN / $ DIS
"H" is output to the terminal, and the outputs A and B of the frequency divider / phase shifter 4 are enabled. As a result, the divider / phase shifter 4 outputs V
Signals are output from A and B by a frequency corresponding to the voltage output from CO3 and a phase difference corresponding to the level output from the DIR2 terminal. Output signals A and B are amplified by power amplifiers 5 and 6 and applied to vibration wave motor 9 via matching coils 7 and 8. Thereby, the vibration wave motor 9 starts to rotate.

[Step 9] 0 is stored in the variable TIMER. TIMER is a counter for measuring a certain time when the frequency is reduced every time a certain time elapses when the rotational movement of the motor is not detected.

[Step 10] The voltage of the battery 15 is set to A /
The 8-bit data A / D converted by the D converter 16 is converted to A
Input from the / Din terminal.

[Step 11] Based on the 8-bit data read in step 10, the frequency reduction width is read from the table and stored in the variable ACCEL1. The table is as shown in FIG. 8, and data of the frequency reduction width corresponding to the 8-bit data is stored in advance.

[Step 12] The variable ACC is set in FREQ.
EL1 is added and stored in FREQ. [Step 13] If FREQ is higher than the lowest frequency MINFREQ within a settable range, step 1 is executed.
Go to step 4, otherwise go to step 17.

[Step 14] Since no pulse input was recognized even when the frequency was scanned up to MINFREQ in step 13, it is determined that the drive is not possible, and 0 is stored in the next scan start frequency FMAX.

[Step 15] Since the motor could not be started, "L" is output to the USM EN / $ DIS terminal, and the outputs A and B of the frequency divider / phase shifter 4 are disabled. . As a result, the motor stops driving.

[Step 16] CNT EN / @ DI
"L" is output to the S terminal, and the up / down counter 13
Is set to the count disable state, and the motor driving process ends.

[Step 17] F is connected to the D / Aout terminal.
Output the value of REQ.

[Step 18] The counter value is input from the up / down counter 13 and stored in the variable FPC.

[Step 19] Variables FPC and FPC
_OLD are compared. If they are equal, the procedure goes to step 20; if they are not equal, the procedure goes to step 22. That is, the detection circuit 12 detects the rotation operation of the pulse plate 10 and up / down.
When the n-counter 13 performs the counting operation, the FPC
≠ Because it becomes FPC _OLD , go to step 22. Also,
If the rotation of the pulse plate 10 is not detected, the FPC
= FPC _OLD , so go to step 20.

[Step 20] Since the rotation of the pulse plate 10 has not been detected, TIMER is incremented.

[Step 21] It is determined whether or not TIMER is equal to the predetermined time TIME_LMT. If they are not equal, the process proceeds to step 18.

[Step 22] Since the rotation of the pulse plate 10 is detected in step 19, the frequency FREQ at that time is stored in FMAX.

[Step 23] The actual rotation speed of the motor is detected by calculating the count frequency of the up / down counter 13.

[Step 24] The actual speed of the motor detected in step 23 is compared with a target speed stored in advance in the memory circuit 14 based on information such as the remaining amount of driving. If the speed is higher than the speed, the process proceeds to step 25;

[Step 25] The voltage of the battery 15 is set to A /
The 8-bit data A / D converted by the D converter 16 is converted to A
Input from the / Din terminal.

[Step 26] Based on the 8-bit data read in step 25, the frequency increase width is read from the table and stored in the variable ACCEL2. The table is the same as that in step 11 and is as shown in FIG.

[Step 27] Since the speed is high,
The value obtained by subtracting the variable ACCEL2 from FREQ is stored in FREQ, and the frequency is scanned in the higher direction.

[Step 28] The voltage of the battery 15 is set to A /
The 8-bit data A / D converted by the D converter 16 is converted to A
Input from the / Din terminal.

[Step 29] Based on the 8-bit data read in step 28, the frequency reduction width is read from the table and stored in the variable ACCEL3. The table is the same as in steps 11 and 26, as shown in FIG.

[Step 30] Since the speed is low,
The value obtained by adding the variable ACCEL3 to FREQ is stored in FREQ, and the frequency is scanned in the lower direction.

[Step 31] Change the value of FREQ to D / A
Output to the out terminal.

[Step 32] The remaining drive amount is calculated from the counter value of the target position of the up / down counter 13 and the variable FPC.

[Step 33] It is determined whether there is a remaining driving amount, whether driving has already been completed by the target driving amount, or whether overrun has occurred. If there is a remaining driving amount, the process proceeds to step 23, and so on. If not, proceed to step 34.

[Step 34] Since driving has already been completed by the target driving amount or overrun has occurred,
"L" is output to the SM EN / @ DIS terminal, and the outputs A and B of the frequency divider / phase shifter 4 are disabled. As a result, the motor stops driving.

[Step 35] CNT EN / @ DI
"L" is output to the S terminal, and the up / down counter 13
Is set to the count disable state, and the driving process ends.

In the above operation, in steps 1 to 8, initialization is performed at the time of startup, confirmation of the initial state of the up / down counter 13, output of the scan start frequency, determination and setting of the rotation direction, initialization of variables And start the motor.

In steps 9 to 22, confirmation is made as to whether or not the apparatus has been started, and frequency scanning is performed. The frequency scan lowers the frequency every time the predetermined time TIME_LMT elapses. Until the activation is confirmed, steps 9 → 10 → 11 → 12 → 1 unless a predetermined time has elapsed.
3 → 17 → 18 → 19 → 20 → 21 → 18 →... When a predetermined time has elapsed, the process returns from step 21 to step 9, and in step 12, the frequency is lowered by ACCEL1.

As the frequency reduction width ACCEL1, a value corresponding to the battery voltage is stored in a table in advance as shown in FIG. As can be seen from the figure, when the voltage is high, the decrease is large, and when the voltage is low, the decrease is small. The reason for such setting is that the slope of the fN characteristic is small when the voltage is high and is large when the voltage is low as shown in FIG. This is to prevent that when the voltage is low, the acceleration is too fast to make it impossible to start.
By changing the frequency reduction width according to the battery voltage in this manner, the motor can always be started with the same start-up characteristics even if the battery voltage fluctuates. Step 19
If the start of the motor is confirmed in step 22, the frequency at that time is stored in step 22. The frequency stored here becomes the sweep start frequency at the time of the next motor drive. Further, the frequency is set to the predetermined value M in step 13 without confirming the start of the motor.
If INFREQ is exceeded, it is determined that the drive is not possible, and the process proceeds to a routine for ending the drive process in steps 14 to 16.

In steps 23 to 35, the rotation speed of the motor is servo-controlled to the target speed. That is, if the speed is higher than the target speed, the frequency is increased by ACCEL2, and if lower than the target speed, the frequency is decreased by ACCEL3.

In steps 25 to 27, the frequency increase width ACCEL2 is set based on the battery voltage. The setting is performed with reference to the table data of FIG. By increasing the frequency increase width when the voltage is high, and by decreasing the frequency increase width when the voltage is low, it is difficult to decelerate when the voltage is high, causing overrun, or increasing the deceleration time when the voltage is low Is preventing that. By changing the frequency increase width in accordance with the battery voltage in this manner, the motor can always be decelerated with good deceleration characteristics even when the battery voltage fluctuates.

In steps 28 to 30, the frequency reduction width ACCEL3 is set based on the battery voltage. This process is the same as steps 10 to 12.

In the above description, the acceleration and the deceleration are set in four stages based on the battery voltage. However, the acceleration and the deceleration can be divided more finely according to the characteristics of the motor and the load.
It can also be set functionally or based on the difference or ratio between the motor speed and the target speed. Also,
Although the table data of FIG. 8 is used for setting ACCEL1, ACCEL2 and ACCEL3, it goes without saying that different table data may be used depending on the acceleration / deceleration characteristics of the motor.

As described above, in this embodiment, by setting the frequency change rate according to the battery voltage, when the voltage is high, the frequency change rate is increased to shorten the acceleration time and improve the stop accuracy. When the voltage is low, the frequency change rate is reduced to perform stable startup and reduce the deceleration time. Therefore, a stable start / stop can be realized regardless of the state of the battery voltage, and the driving time can be reduced.

FIG. 5 is a block diagram showing a second embodiment of the present invention. The case where a V / F converter is used as means for detecting the battery voltage is taken as an example.

In the figure, the same components as those in the first embodiment are denoted by the same reference numerals. The difference from the first embodiment is that a V / F converter is provided instead of the A / D converter 16. And the A / Din terminal of the microcomputer 1 is V / Fi
Since only the n terminal is provided, only different points will be described.

A V / F converter 17 outputs a frequency signal (rectangular wave) according to the voltage of the battery 15. In this embodiment, it is assumed that the output signal frequency increases as the battery voltage increases. The V / Fin terminal of the microcomputer 1 is a signal input terminal from the V / F converter 17.

FIGS. 6 and 7 are flowcharts showing a program flow executed by the microcomputer 1 of FIG.
The microcomputer 1 executes a control operation according to the program flow. The difference from the first embodiment is that step 10
Since only the setting of the frequency change rate in steps 1 to 105 and steps 106 to 112 is performed, only different points will be described.

[Step 101] A signal is input from the V / Fin terminal.
If "L", the process proceeds to step 105.

[Step 102] It is determined whether or not the flag FCFLAG indicating that the frequency has been changed is 0. If 0, the process proceeds to step 103; if 1, the process proceeds to step 13.

[Step 103] 1 is added to the variable FREQ, and the result is stored in the variable FREQ.

[Step 104] 1 is stored in the flag FCFLAG indicating that the frequency has already been changed.

[Step 105] 0 is stored in a flag FCFLAG indicating that the frequency has already been changed.

In steps 101 to 105, the rising of the signal output from the V / F converter 17 is detected, and the driving frequency of the vibration wave motor 9 is changed in synchronization with the detection. As described above, the V / F converter 17 has a characteristic that the output signal frequency increases as the voltage of the battery 15 increases. Therefore, when the battery voltage is high, the driving frequency change rate of the vibration wave motor 9 increases, and the battery voltage decreases. And the drive frequency change rate of the vibration wave motor 9 becomes small. Therefore, even if the battery voltage fluctuates, the motor can always be started at the optimum acceleration.

[Step 106] A signal is input from the V / Fin terminal.
If "L", the process proceeds to step 112.

[Step 107] It is determined whether or not a flag FCFLAG indicating that the frequency has already been changed is 0. If 0, the process proceeds to step 108; if 1, the process proceeds to step 31.

[Step 108] The actual speed of the motor is compared with a target speed previously stored in the memory circuit 14 based on information such as the remaining amount of driving. If the actual speed is higher than the target speed, The process proceeds to step 109, and if it is late, the process proceeds to step 110.

[Step 109] Since the speed is high, a value obtained by subtracting the variable 1 from FREQ is stored in FREQ, and the frequency is scanned higher.
Proceed to 11.

[Step 110] Since the speed is low, a value obtained by adding variable 1 to FREQ is stored in FREQ.
After scanning the frequency to the lower side, step 111
Proceed to. [Step 111] 1 is stored in a flag FCFLAG indicating that the frequency has been changed.

[Step 112] "0" is stored in the flag FCFLAG indicating that the frequency has been changed.

In steps 106 to 112, the rotation speed of the motor is servo-controlled to the target speed. That is, the frequency is increased by 1 when the frequency is faster than the target speed, and decreased by 1 when the frequency is lower than the target speed. The frequency of changing the frequency is synchronized with the rise of the output signal of the V / F converter 17 as in steps 101 to 105. Therefore, when the voltage is high, the frequency increases, and when the voltage is low, the frequency decreases. Therefore, the motor can always be controlled with optimal acceleration / deceleration under any voltage condition.

In the above description, the motor drive frequency is changed one by one when it is changed. However, the drive frequency is changed one by one according to the characteristics of the motor and the load, or the difference or ratio between the motor speed and the target speed is determined. It is also possible to set the original. Further, the rising of the output signal of the V / F converter 17 is detected in the drive processing routine. However, the microcomputer 1 may be interrupted at the rising edge, and the frequency changing operation may be performed in the interrupt processing routine. Needless to say.

As described above, in this embodiment, as in the first embodiment, by setting the frequency change rate in accordance with the battery voltage, stable start / stop can be performed under any voltage condition. It can be realized, and the driving time can be shortened.

In the above-described embodiment, an annular vibration wave motor, which is one of representative examples of the vibration driving device, has been described as an example. An ultrasonic (vibration wave) motor such as a type that causes elliptical motion to the surface particles of the driving surface may be used, or a type in which the driving surface of the vibrator is brought into contact with a fixed contact body to move the vibrator. It goes without saying that the present invention can be applied to a vibration driving device such as an ultrasonic (vibration wave) motor, and a device for bringing a sheet member such as paper into contact with a vibrator and conveying the sheet. is there.

[0092]

According to the present invention, the acceleration and deceleration at the time of starting and stopping can be controlled at optimum values without being affected by fluctuations in the power supply conditions, and stable driving can be guaranteed, and the driving time can be ensured. And the stopping accuracy can be improved.

Further, there is an effect that a drive control device for a vibration driving device such as a vibration wave motor or the like can be realized at a low cost because the structure is simplified because the constant voltage means is not required.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a plan view showing a polarization state of a piezoelectric element of the stator shown in FIG.

FIG. 3 is a flowchart showing the operation of the first embodiment.

FIG. 4 is a flowchart showing the operation of the first embodiment.

FIG. 5 is a block diagram showing a second embodiment.

FIG. 6 is a flowchart showing the operation of the second embodiment.

FIG. 7 is a flowchart showing the operation of the second embodiment.

FIG. 8 is a table showing a frequency change table used in the first and second embodiments.

FIG. 9 is a diagram showing the voltage dependence of the driving frequency and the rotation speed of the vibration wave motor.

[Explanation of symbols]

 Reference Signs List 1 microcomputer 2 D / A converter 3 VCO 4 frequency divider / phase shifter 5, 6 power amplifier 7, 8 coil 9 vibration wave motor 10 pulse plate 11 interrupter 12 detection circuit 13 up / down counter 14 memory circuit 15 battery 16 A / D converter 17 V / F converter

Claims (2)

(57) [Claims] 1. A a frequency voltage of the transducer electrical - acceleration decreases and frequency voltage supplying means for applying the mechanical energy conversion element, the frequency of the frequency voltage outputted from the peripheral wave voltage supplying means
In the vibration drive device that performs the acceleration operation, the decrease width in the frequency reduction operation in the acceleration operation or
The execution frequency of the frequency reduction operation was determined according to the frequency voltage value.
Vibration drive device characterized in that it is set to decrease width or frequency
Place. 2. The method according to claim 1, wherein the frequency voltage is converted into an electric-mechanical energy
Means for supplying a frequency voltage to the conversion element, and the frequency voltage
Increase the frequency of the frequency voltage output from the supply means during deceleration
In the vibration drive device that performs the deceleration operation, the increase width in the frequency increase operation in the deceleration operation or
The execution frequency of the frequency increasing operation was determined according to the frequency voltage value.
Vibration drive device characterized in that it is set to increase width or frequency
Place.