JP2022068434A - Vibration type drive device and drive method thereof - Google Patents

Abstract

To detect the disconnection or the number of disconnections of a vibration body of a vibration type actuator in which a plurality of vibration bodies are connected.SOLUTION: A vibration type drive device includes a control unit that outputs a command signal, a drive unit that outputs a drive signal on the basis of the command signal, a vibration body unit in which two or more vibration bodies that vibrate on the basis of the drive signal are connected, drive signal analysis means that analyzes the drive signal and outputs the analysis result, and determination means that determine the presence or absence of the breakage of a wiring connected to the vibration body on the basis of the analysis result.SELECTED DRAWING: Figure 1

Description

It relates to a drive device for an actuator using ultrasonic vibration.

In a vibration type actuator using a vibrating body that is vibrated by an electric-mechanical energy conversion element (piezoelectric element, electric strain element, etc.), a method of measuring the applied voltage to detect a defect such as disconnection of the vibrating body is known. ing. For example, Patent Document 1 shows an example in which disconnection is detected by detecting the generation of a high frequency component of an AC voltage applied to a vibrating body via an inductor. Further, Patent Document 2 shows an example in which disconnection is detected by detecting the Q value of the peak characteristic of the frequency characteristic of the applied voltage that changes depending on the characteristic of the transformer for boosting and the change of the peak frequency.

In the case of a single vibrating body as in Patent Document 1, the change in the applied voltage due to the disconnection is large, and the occurrence of the disconnection can be detected by the generation of the high frequency component. However, a plurality of vibrating body units in which an inductor element and a vibrating body are connected in parallel are connected in series, or a vibrating body is connected in parallel to the secondary side of a plurality of transformers and the primary side of each transformer is connected in series. The connected series-connected vibrating body device has the following problems.

That is, even if one vibrating body is disconnected, the waveform change of the applied voltage applied to both ends of the series connection is small, and the high frequency component appearing in the frequency region higher than the drive frequency increases or decreases depending on the frequency. Therefore, it was not possible to determine the presence or absence of disconnection simply because a high frequency component was generated.

Further, if a method of detecting the peak frequency and the Q value by paying attention to the peak characteristic of the frequency characteristic of the applied voltage by utilizing the frequency characteristic of the secondary side of the transformer as in Patent Document 2, a defect of each vibrating body is used. Can be detected. However, in the series-connected vibrating body device as described above, it is necessary to detect the AC voltage applied to all the vibrating bodies, and while it is possible to detect the defective part, there is a drawback that the circuit scale becomes large. rice field. In addition, frequency sweeping in the high frequency range and detection of peak frequency and Q value using pseudo-random numbers are performed independently by superimposing a high frequency voltage separately while applying a normal drive voltage, resulting in speed fluctuations and differences. There was a problem that it was easy to cause noise. In a vibrating unit in which a plurality of vibrating bodies are connected, even if one of the vibrating bodies is disconnected, the applied voltage is supplied to the other vibrating bodies and can be driven to some extent, so even if the disconnection occurs. It has the property of being able to continue driving. However, there is a problem that the performance deterioration may accelerate because the load on other vibrating bodies becomes heavy in the disconnected state.

Patent No. 5716624 JP-A-2018-78769

In view of the above problems, it is an object of the present invention to detect disconnection of a vibrating body during driving in a vibrating body unit in which a plurality of vibrating bodies are connected.

The vibration type drive device for solving the above problems includes a control unit that outputs a command signal, a drive unit that outputs a drive signal based on the command signal, and two or more vibrating bodies that vibrate based on the drive signal. It includes a series of vibrating body units, a driving signal analysis means that analyzes the driving signal and outputs an analysis result, and a determination means for determining whether or not the wiring connected to the vibrating body is broken based on the analysis result.

According to the present invention, it is possible to detect a disconnection of a vibrating body during normal driving in a vibrating type driving device having a vibrating type unit in which a plurality of vibrating bodies are connected. Further, even if a disconnection occurs during normal driving, the drive control can be quickly performed according to the disconnection situation, so that the influence of the disconnection on the peripheral mechanism and the user can be reduced.

The figure which shows the 1st example of the drive circuit of the vibration type actuator of 1st Embodiment The figure which shows the 1st example of the structure of the vibration type actuator. Diagram showing electrical connections within a vibrating actuator The figure which shows the 1st example of the frequency characteristic change of the drive voltage amplitude at the time of disconnection of the 1st Example. The figure which shows the change of the drive voltage waveform at the time of disconnection of 1st Example The figure which shows the 1st example of the analysis result when it was driven by the pulse signal of the duty 50% of the 1st Example. The figure which shows the 1st example of the analysis result at the time of driving with the pulse signal of the duty 38% of 1st Example. The figure which shows the 1st example of the relationship between the number of disconnections and the analysis result at the time of driving with the pulse signal of the duty 50% of 1st Example. The figure which shows the 1st example of the relationship between the number of disconnections and the analysis result at the time of driving with the pulse signal of the duty 38% of 1st Example. The figure which shows the 2nd example of the drive circuit of the vibration type actuator of 1st Example. The figure which shows the 2nd example of the frequency characteristic change of the drive voltage amplitude at the time of disconnection of the 1st Example. The figure which shows the 2nd example of the analysis result at the time of driving with the pulse signal of the duty 50% of 1st Example. The figure which shows the 3rd example of the drive circuit of the vibration type actuator of 1st Example. The figure which shows the 3rd example of the frequency characteristic change of the drive voltage amplitude at the time of disconnection of the 1st Example. The figure which shows the 3rd example of the analysis result at the time of driving with the pulse signal of the duty 50% of 1st Example. The figure which shows the 2nd example of the analysis result at the time of driving with the pulse signal of the duty 38% of 1st Example. The figure which shows the 1st example of the drive circuit of the vibration type actuator of 2nd Example The figure which shows the example of the frequency characteristic change of the drive voltage amplitude at the time of disconnection of the 2nd Example. The figure which shows the example of the change of the drive voltage waveform at the time of disconnection of the 2nd Example. The figure which shows the example of the analysis result when it was driven by the pulse signal of the duty 50% of the 2nd Example. The figure which shows the 2nd example of the drive circuit of the vibration type actuator of 2nd Example The figure which shows the structure of the vibrating body of the vibrating type actuator of 3rd Example. The figure which shows the vibration mode of the vibrating body of 3rd Example The figure which shows the structural example of the vibration type actuator of 3rd Example. The figure which shows the drive circuit of the vibration type actuator of 3rd Embodiment The figure which shows the example of the frequency characteristic change of the drive voltage amplitude at the time of disconnection of the 3rd Example. The figure which shows the change of the drive voltage waveform at the time of disconnection of the 3rd Example. The figure which shows the example of the analysis result when it was driven by the pulse signal of the duty 50% of the 3rd Example. A flowchart showing an operation example of the CPU 15 of the third embodiment. A flowchart showing an operation example of waveform analysis, disconnection determination, and vibration amplitude control of the CPU 15 of the third embodiment. The figure which shows the drive circuit of the vibration type actuator of 4th Embodiment The figure which shows the example of the frequency characteristic change of the drive current at the time of disconnection of the 4th Example. The figure which shows the example of the analysis result when it was driven by the pulse signal of the duty 50% of the 4th Example. A flowchart showing an operation example of waveform analysis, disconnection determination, and vibration amplitude control of the CPU 15 of the fourth embodiment.

An example of an embodiment for carrying out the present invention is a vibrating body in which a control unit that outputs a command signal, a drive unit that outputs a drive signal based on the command signal, and two or more vibrating bodies that vibrate based on the drive signal are connected. Equipped with a unit. Further, it is a vibration type drive device including a drive signal analysis means that analyzes a drive signal and outputs an analysis result, and a determination means that determines whether or not the wiring connected to the vibrating body is broken based on the analysis result.

Another example of the embodiment for carrying out the present invention is the following control method. That is, the control unit outputs a command signal to the drive unit, and the drive signal output by the drive unit based on the command signal vibrates the vibrating body unit in which two or more vibrating bodies are connected. At the same time, it is a control method of a vibration type drive device that analyzes the drive signal, outputs the analysis result, and determines whether or not the wiring connected to the vibrating body is broken based on the analysis result.

With this configuration, it is possible to detect a disconnection of a vibrating body during normal driving in a vibrating actuator in which a plurality of vibrating bodies are connected. Hereinafter, the details will be described with reference to the drawings.

FIG. 1 is a diagram showing a drive circuit of the vibration type actuator of the first embodiment. Reference numerals 1, 2, and 3 are transformers in which a vibrating element, 5, 6, and 7 are connected in series with an inductor on the primary side, and vibrating bodies 1, 2, and 3 are arranged in parallel on the secondary side of transformers 5, 6, and 7, respectively. The portion surrounded by the dotted line connected to the above shows the internal circuit of the vibrating actuator 10 as the vibrating body unit. The inductance value of the secondary coil of the transformer connected in parallel to each vibrating body is matched at a predetermined frequency close to the resonance frequency of the vibrating actuator 10.

That is, assuming that the matching frequency is F ₀ , the braking capacitance value is C ₀ , and the inductance value of the secondary coil of the transformer is L ₀ , these relationships are expressed by Equation 1.

１２は周波数指令に応じたパルス信号を出力する矩形電圧生成手段であり、インダクタとコンデンサの直列回路で構成される波形整形手段１１を介して駆動電圧を振動型アクチュエータ１０に出力している。１３は振動型アクチュエータ１０に流れる電流を計測する為の抵抗で、振動体１、２、３の振動速度に比例した電圧を出力する。したがって振動型アクチュエータ１０の全体を代表した電圧の値を抵抗１３の出力から検出できる。

Reference numeral 12 denotes a rectangular voltage generating means that outputs a pulse signal according to a frequency command, and outputs a drive voltage to the vibration type actuator 10 via a waveform shaping means 11 composed of a series circuit of an inductor and a capacitor. Reference numeral 13 is a resistance for measuring the current flowing through the vibrating actuator 10, and outputs a voltage proportional to the vibrating speed of the vibrating bodies 1, 2, and 3. Therefore, the value of the voltage representing the entire vibration type actuator 10 can be detected from the output of the resistor 13.

The amplitude of the vibrating body is accurately proportional to the value obtained by integrating this vibration velocity with time, but since the amplitude of the vibration velocity is generally proportional to the vibration amplitude, the amplitude of the vibration velocity signal is controlled in the following embodiment. The vibration amplitude is controlled by.

14 is an amplitude detecting means for detecting the amplitude of the vibration velocity signal detected by the resistor 13, and 15 is a known CPU that outputs a vibration amplitude command of the vibration type actuator 10 in response to a command from a command means (not shown). be. Reference numeral 16 is an amplitude comparing means for comparing the vibration amplitude command and the output of the amplitude detecting means 14, and 17 is an amplitude controlling means for outputting a frequency command to the rectangular voltage generating means 12 according to the output of the amplitude comparing means 16. Reference numeral 18 is a drive signal analysis means for analyzing the waveform of the drive voltage of the vibration type actuator 10, and the CPU 15 as a control unit outputs a command signal such as an ON-OFF command according to the waveform analysis result of the drive signal analysis means 18. do. Based on this command signal, the drive unit outputs the drive signal to the vibrating body unit in which two or more vibrating bodies are connected.

The CPU 15, which is a control unit, outputs a command signal such as an ON-OFF command to a rectangular voltage generating means 12 which is a drive unit, and controls operations such as driving and stopping of the vibration type actuator 10.

The vibrating body unit illustrated in FIG. 1 has a configuration in which a vibrating body is connected in parallel to each of the secondary sides of a plurality of transformers whose primary side is connected in series, and the primary side of the plurality of transformers is the drive signal. Is configured to be applied. In addition, it is provided with a waveform shaping means inserted between the rectangular voltage generating means and the vibrating body unit.

In this way, the vibrating actuator 10 as a vibrating body unit is configured by connecting two or more vibrating bodies in a row, and the vibrating bodies are configured to be driven by a common command signal issued by the CPU 15 as a control unit. Has been done.

Here, a first example of the vibration type actuator of this embodiment is shown. FIG. 2 is a diagram showing a structure of a vibrating actuator that rotates a cylindrical shaft by bringing three vibrating bodies into contact with the outer circumference of the cylindrical shaft. 1, 2, and 3 are vibrating bodies that vibrate in the vertical direction (direction of the arrow), and 4 is a cylindrical shaft. In this embodiment, the vibrating bodies 1, 2, and 3 are arranged substantially evenly at intervals of 120 ° on the circumference of the cylindrical shaft 4. The cylindrical shaft 4 rotates clockwise by exciting the vibrations 1, 2, and 3 in the vertical direction. The cylindrical shaft corresponds to a common contact body in contact with a vibrating body unit in which two or more vibrating bodies are connected, and moves relative to the vibrating body in the direction of the resultant force generated by driving the vibrating bodies 1, 2, and 3.

FIG. 3 is a diagram showing an electrical connection in the vibrating actuator 10. Reference numerals 5, 6 and 7 are transformers, and the secondary coils of the transformers 5, 6 and 7 are connected in parallel to the piezoelectric bodies bonded to the vibrating bodies 1, 2 and 3. Reference numeral 8 is a connector for inputting an AC voltage to the vibrating actuator 10, in which the primary coils of the transformers 5, 6 and 7 are connected in series, and both ends thereof are connected. Reference numeral 9 denotes a donut-shaped hollow case in which the vibrating body is housed, and these are integrated to form a vibrating actuator 10 in which a plurality of vibrating bodies are connected.

Further, the vibrating bodies 1, 2, and 3 have a protruding portion that is pressure-contacted with the cylindrical shaft 4 at every 120 ° in the hollow cylindrical portion through which the cylindrical shaft 4 of the case 9 is passed, and the support member includes a spring structure (not shown). It is pressed against the cylindrical shaft 4 with a constant pressure. Next, the operation of the CPU 15 will be described. The CPU 15 outputs a command signal related to the vibration amplitude based on a table of vibration amplitude corresponding to the speed command in response to a speed command from a command means (not shown). During driving, the analysis result of the drive signal analysis means 18 is periodically monitored, and if the analysis result is out of the predetermined range, it is determined that any of the vibrating bodies 1, 2 and 3 is disconnected, and the vibration amplitude command is set to 0. And stop the vibration type actuator. Further, it may operate so as to notify the command means (not shown) of the occurrence of disconnection at the same time as stopping.

Next, the operation of the drive signal analysis means 18 will be described. FIG. 4 shows a change in the frequency characteristic of the drive voltage amplitude when the connection of the vibrating body of the vibrating actuator 10 is disconnected. It is assumed that the rectangular voltage generating means 12 outputs a drive signal which is a sinusoidal voltage signal, the frequency is swept, and the amplitude of the drive voltage is measured. The range of the drive frequency of the vibration type actuator 10 in the present embodiment is approximately between 93 kHz and 98 kHz.

In FIG. 4, the solid line is no disconnection, the broken line is the wiring connected to one of the vibrating bodies, the alternate long and short dash line is the wiring connected to each of the two vibrating bodies, and the dotted line is connected to each of all the vibrating bodies. This is the case when the wiring is broken. In FIG. 4, F ₁ indicates the frequency of the fundamental wave of a driving voltage waveform within the frequency range used for normal driving, F ₂ indicates the frequency of the second harmonic, and F ₃ indicates the frequency of the third harmonic. ing. Comparing the voltage amplitudes of each order in FIG. 4, it can be seen that the ratio of the amplitudes between the orders differs depending on the number of disconnections and the waveform changes. Moreover, since the frequency F3 of the _third harmonic of the drive voltage is near the frequency (around 310 kHz) of the lowest point of the valley of the frequency characteristic when there is no disconnection, the amplitude of the third harmonic is large at the time of disconnection. Since it is changing, the waveform change at the time of disconnection is increased.

FIG. 5 shows changes in the waveform of the drive voltage. FIG. 5A shows a case where the rectangular voltage generating means 12 outputs a pulse signal having a duty of 50%, and FIG. 5B shows a case where the rectangular voltage generating means 12 outputs a pulse signal having a duty of 38%. The solid line is the case where there is no disconnection, the broken line is the case where one vibrating body is broken, the alternate long and short dash line is the case where the two vibrating bodies are broken, and the dotted line is all broken.

In both FIGS. 5 (a) and 5 (b), when a disconnection occurs, a part of the smooth waveform changes sharply, and it can be clearly seen that the rectangular wave is superimposed. Further, as the number of disconnections increases, the steep waveform becomes larger while the amplitude becomes smaller, and it can be seen that the ratio of the superimposed rectangular wave component increases.

FIG. 6 shows an example of the waveform analysis result of the drive signal analysis means 18 when the duty of the pulse signal output by the rectangular voltage generation means 12 is 50%. 6 (a) and 6 (b) are graphs calculated based on the "average value of absolute values" and the effective value of the drive voltage by changing the frequency of the drive voltage. FIG. 6A is the result of the waveform ratio (“average value of absolute value” / effective value), and FIG. 6B is the result of effective value- “average value of absolute value”.

The closer the effective value of the AC signal is to the square wave, the closer it is to the "mean value of the absolute value" of the AC signal. Efficient value-The "mean value of absolute values" is decreasing.

The waveform analyzed in this way may be a waveform of an average value of the absolute values of the drive voltage with respect to the frequency of the drive voltage, or a waveform of an effective value of the drive voltage with respect to the frequency of the drive voltage.

6 (c) and 6 (d) are graphs calculated from the amplitude of the harmonics of the drive voltage. FIG. 6 (c) shows the total harmonic distortion rate (value obtained by dividing the amplitude of the high frequency component (harmonic component) other than the fundamental wave by the amplitude of the fundamental wave) for evaluating the degree of the high frequency component, FIG. 6 (d). Is a graph showing the value obtained by dividing the amplitude of the third harmonic by the amplitude of the fundamental wave. As a method for measuring the amplitude of a fundamental wave or a harmonic, there are the following methods in addition to the method using a known FFT (Fast Fourier Transform). That is, there are a method of separating the fundamental wave and the high frequency component (harmonic component) using a low-pass filter and measuring the amplitude of each, and a method of extracting a harmonic of a specific order with a bandpass filter and measuring the amplitude. .. Further, in this embodiment, the waveform is analyzed by using the drive signal analysis means 18, but the time-series waveform of the drive voltage is read into the CPU 15 by using an A / D converter (not shown), and the calculation such as FFT is used. Waveform analysis may be performed. In that case, the sampling frequency of the A / D converter can be lowered by attenuating the fifth-order or higher harmonics with a low-pass filter before inputting with the A / D converter. Since the influence of harmonics of the third order or lower is large on the change of the waveform, it is desirable to sample at a sampling frequency sufficient to detect the third harmonic (for example, a frequency 12 times or more the fundamental wave). In this way, analysis may be performed from the waveforms of the amplitude of the third harmonic and the amplitude of the fundamental wave with respect to the frequency of the drive voltage.

From the frequency characteristics of the drive voltage amplitude in Fig. 4, the harmonic components of the second and higher orders of the square wave are almost increased due to disconnection, so the harmonic distortion rate and the amplitude of the third harmonic (frequency near F ₃ ) are the basics. The value divided by the amplitude of the wave (frequency near F1) increases as the _number of disconnections increases.

The threshold value for determining the presence or absence of disconnection is shown by a long chain line in each graph of FIGS. 6 (a), (b), (c), and (d). By using this threshold value, it is possible to determine the presence or absence of disconnection from the result of each waveform analysis calculation regardless of the frequency from 94 kHz to 97 kHz during driving.

FIG. 7 shows an example of the waveform analysis result of the drive signal analysis means 18 when the duty of the pulse signal output by the rectangular voltage generation means 12 is 38%. 7 (a) and 7 (b) are graphs calculated based on the "average value of absolute values" and the effective value of the drive voltage by changing the frequency of the drive voltage. FIG. 7A is the result of the waveform ratio (“average value of absolute value” / effective value), and FIG. 7B is the result of effective value- “average value of absolute value”. 7 (c) and 7 (d) are graphs calculated from the amplitude of the harmonics of the drive voltage. FIG. 7 (c) shows the total harmonic distortion rate (value obtained by dividing the amplitude of high-frequency components (harmonic components) other than the fundamental wave by the amplitude of the fundamental wave), and FIG. 7 (d) shows the amplitude of the third-order harmonic. It is a graph which shows the value divided by the amplitude of the fundamental wave.

The analysis results of FIGS. 7A and 7B change uniformly in the increasing or decreasing direction due to the disconnection, but the results of the disconnection 0 and the disconnection 1 are close to each other, and even if a threshold value is set between them, the disconnection occurs. The reliability of the judgment is low. In the analysis results of FIGS. 7 (c) and 7 (d), since there is a sufficient gap between the disconnection 0 and the disconnection 1, it is relatively easy to determine the presence or absence of the disconnection.

FIG. 8 is a graph showing a change in the analysis result with respect to the number of disconnections when the frequency when the duty of the pulse signal output by the rectangular voltage generating means 12 is 50% is fixed to a predetermined frequency based on FIG. 8 (a) is the waveform factor, FIG. 8 (b) is the effective value- "mean value of absolute value", FIG. 8 (c) is the total harmonic distortion, and FIG. 8 (d) is the third harmonic. It is a graph which shows the value which divided the amplitude by the amplitude of a fundamental wave. Since each value changes uniformly depending on the number of disconnections in the frequency range of 94 kHz to 97 kHz as shown in FIG. 8, it is also possible to obtain the number of disconnections.

FIG. 9 is a graph showing changes in the analysis result with respect to the number of disconnections when the frequency when the duty of the pulse signal output by the rectangular voltage generating means 12 is 38% is fixed to a predetermined frequency based on FIG. 7. 9 (a) is the waveform factor, FIG. 9 (b) is the effective value- "mean value of absolute value", FIG. 9 (c) is the total harmonic distortion, and FIG. 9 (d) is the third harmonic. It is a graph which shows the value which divided the amplitude by the amplitude of a fundamental wave.

Similar to the explanation of FIG. 7, the analysis results of FIGS. 9A and 9B change uniformly in the increasing or decreasing direction due to the disconnection, but the results between the number of disconnections are close to each other and the number of disconnections. There is a possibility that the error will be large even if it is calculated. Since the analysis results of FIGS. 9 (c) and 9 (d) have a sufficient gap between the disconnection 0 and the disconnection 1, the number of disconnections can be obtained in the same manner as in the case of the duty of 50%.

The reason why there is a big difference between the analysis results of the duty 50% and the duty 38% is that the amplitude ratios of the second and third harmonics of the pulse signal are different. Since the frequency characteristics of the drive voltage amplitude in FIG. 4 have a large change in characteristics due to disconnection around the frequencies of the second and third harmonics, the difference in the amplitude ratio of the second and third harmonics of the pulse signal is the analysis result. Affecting the difference. Since the analysis result changes depending on the driving conditions (duty and driving frequency) in this way, it is effective to switch the waveform analysis method depending on the driving conditions in the application in which the driving conditions change.

FIG. 10 shows a configuration in which the waveform shaping means 11 of the drive circuit of the vibration type actuator of FIG. 1 is changed to the waveform shaping means 19 having only an inductor. The operation of the CPU 15 is the same as that of the above example, but the change in the frequency characteristic of the amplitude of the drive voltage when the vibrating body of the vibrating actuator 10 is disconnected is different, so that the analysis result of the drive signal analysis means 18 is different.

FIG. 11 is a diagram showing changes in the frequency characteristics of the amplitude of the drive voltage when the connection of the vibrating body of the vibrating actuator 10 in the driving circuit of the vibrating actuator 10 of FIG. 10 is disconnected.

Since the waveform shaping means does not have a capacitor for cutting DC, the frequency characteristic of the drive voltage amplitude in the low frequency region is increased as compared with the characteristic of FIG.

FIG. 12 shows an example of the waveform analysis result of the drive voltage by the drive signal analysis means 18 when the duty of the pulse signal output by the rectangular voltage generation means 12 is 50%. FIG. 12 (a) shows the waveform factor, FIG. 12 (b) shows the effective value- "the average value of the absolute values", and FIG. 12 (c) shows the total harmonic distortion (the amplitude of the harmonic component other than the fundamental wave is the fundamental wave). (Value divided by the amplitude of), FIG. 12 (d) is a graph showing the value obtained by dividing the amplitude of the third harmonic by the amplitude of the fundamental wave. In the graph of FIG. 11, the characteristics other than the disconnection 3 in which all the wires are disconnected have little change in amplitude in the _high frequency region (frequency of F2 or higher). On the other hand, since the amplitude increases as the frequency approaches 100 kHz from 90 kHz, the change in the waveform due to disconnection decreases as the frequency of the fundamental wave (near F1) approaches ₁₀₀ kHz. Therefore, in the analysis results of FIGS. 12A, 12C, and 12D, the higher the frequency, the smaller the changes in disconnection 0, disconnection 1, and disconnection 2.

In each analysis result of FIG. 12, the change due to the disconnection is small near 97 kHz, but each value changes uniformly depending on the number of disconnections. Therefore, it is possible to determine the presence or absence of disconnection and the number of disconnections by measuring the characteristics of the amplitude of the drive voltage generated by the disconnection in advance and preparing each analysis result as a comparison table for each frequency.

FIG. 13 is a diagram showing a third example of the drive circuit of the vibration type actuator in the case where the configuration of the vibration type actuator is different. In the above example, the transformers 5, 6 and 7 are connected in parallel with the vibrating bodies 1, 2 and 3 to form the vibrating actuator 10. In this example, the inductors 20, 21, and 22 are connected in parallel to the vibrating bodies 1, 2, and 3, and the vibrating bodies 1, 2, and 3 are connected in series to form a vibrating actuator 23 as a vibrating body unit. There is. That is, a pair of inductors and a vibrating body connected in parallel form the vibrating body unit in which a plurality of pairs are connected in series.

Since the operation of each part is the same as the above example, only the operation of the drive signal analysis means 18 will be described.

FIG. 14 shows a change in the frequency characteristic of the amplitude of the drive voltage when the connection of the vibrating body of the vibrating actuator 23 is disconnected. Similar to the above description, the frequency is swept and the amplitude of the drive voltage is measured on the assumption that the rectangular voltage generation means 12 outputs a sine wave.

The solid line is the case where there is no disconnection, the broken line is the case where one vibrating body is broken, the alternate long and short dash line is the case where the two vibrating bodies are broken, and the dotted line is all broken. F ₁ indicates the frequency of the fundamental wave of a certain drive voltage waveform used in normal driving, F ₂ indicates the frequency of the second harmonic, and F ₃ indicates the frequency of the third harmonic.

FIG. 15 shows an example of the waveform analysis result of the drive signal analysis means 18 when the duty of the pulse signal output by the rectangular voltage generation means 12 is 50%. FIG. 15 (a) shows the waveform factor, FIG. 15 (b) shows the effective value- "the average value of the absolute values", and FIG. 15 (c) shows the total harmonic distortion (the amplitude of the harmonic component other than the fundamental wave is the fundamental wave). (Value divided by the amplitude of), FIG. 15 (d) is a graph showing the value obtained by dividing the amplitude of the third harmonic by the amplitude of the fundamental wave. Since the gap between the disconnection 0 and the disconnection 1 is large in each analysis result, it is easy to determine the presence or absence of the disconnection. The long chain line in each graph is a threshold value for determining the disconnection.

FIG. 16 shows an example of the waveform analysis result of the drive voltage by the drive signal analysis means 18 when the duty of the pulse signal output by the rectangular voltage generation means 12 is 38%. 16 (a) is the waveform factor, FIG. 16 (b) is the effective value- "average value of absolute values", and FIG. 16 (c) is the total harmonic distortion (amplitude of harmonic components other than the fundamental wave is the fundamental wave). 16 (d) is a graph showing the value obtained by dividing the amplitude of the third harmonic by the amplitude of the fundamental wave. The characteristics other than the total harmonic distortion in FIG. 16C are the same as in the case of the duty of 50% in FIG. 15 except that the gap between the number of disconnections is narrowed, and it is easy to determine the presence or absence of the disconnection. However, in the total harmonic distortion factor of FIG. 16 (c), the order of disconnection 0 and disconnection 1 is interchanged as compared with FIG. 15 (c). The decrease in the total harmonic distortion indicates that the high frequency component decreases relative to the fundamental wave component, and the characteristic of FIG. 16C shows that the high frequency component of the drive voltage decreases due to the disconnection 1. It shows that it is. Therefore, in order to determine the presence or absence of disconnection using the total harmonic distortion factor in FIG. 16 (c), two threshold values, large and small, are required as in the two long chain lines in the figure. Further, since there is no graph intersection between the number of disconnections within the range of 94 kHz to 97 kHz in any of the analysis methods of FIG. 16, if the analysis result of the drive voltage waveform due to the disconnection is prepared in advance as a comparison table and the judgment is made based on the analysis result. It is possible to determine the disconnection.

In the above description, it was shown that different circuits, different duties, and different drive frequencies have different effects on the drive voltage waveform due to disconnection. In the explanation of FIG. 16, it is shown that the high frequency component may decrease even when the wire is broken, and the disconnection cannot be determined simply by the presence or absence of the high frequency component depending on the driving conditions. It was also shown that if the analysis result of the drive voltage waveform due to the disconnection is prepared in advance as a comparison table, the frequency command, the analysis result and the comparison table are used, and if the judgment is made based on the frequency command, the disconnection can be determined.

Further, in the above description, the method for determining the disconnection has been described using the examples of the four waveform analysis methods, but any arithmetic method or measurement method whose output changes depending on the waveform can be used. For example, a steep waveform appears due to disconnection, and the magnitude changes depending on the number of disconnections. Therefore, the maximum value of the change in the drive voltage per unit time may be used. It is also possible to determine the disconnection based on the harmonic amplitude of a specific order.

In the above description, the pulse signal which is the output of the rectangular voltage generation means 12 is used as the drive voltage, but other waveforms may be used. Even if it is a triangular wave, a sawtooth wave, or a PWM modulated wave that is the output of a known class D amplifier, if the waveform contains many relatively low-order harmonics of the 5th or lower order, the waveform change due to disconnection is relatively large. It can be used to detect disconnection.

In this way, the drive signal analysis means analyzes the waveform of the output voltage or output current of the waveform shaping means, and determines the waveform factor, the harmonic distortion factor, the difference between the effective value and the average value of the absolute value, and the harmonic amplitude. It is good to detect the corresponding value. It is more desirable to have a waveform shaping means, but it is not essential and signal processing may be performed directly.

FIG. 17 is a diagram showing a drive circuit of the vibration type actuator of the second embodiment. In the vibration type actuator of the above embodiment, the vibrating bodies 1, 2, 3 and the transformers 5, 6 and 7 are connected in parallel, but in this embodiment, the matching adjusting capacitors 24, 25 and 26 are additionally connected in parallel. ing. Since the operation of each part is the same as that of the first embodiment, the description thereof will be omitted, and the analysis of the drive voltage waveform and the determination of the disconnection will be described.

The capacitor connected in parallel to each vibrating body is a capacitor for adjusting the matching frequency, and its capacitance value C ₁ is F ₀ for the matching frequency, C ₀ for the braking capacitance value, and the inductance value of the secondary coil of the transformer. Is L ₀ , and these relationships are expressed by Equation 2.

トランスの２次側コイルのインダクタンス値Ｌ_０や制動容量値Ｃ_０の値はバラツキが大きいので、マッチング調整用コンデンサ（静電容量値Ｃ_１）を並列に接続することでマッチング周波数Ｆ_０を揃えるようにしている。

Since the values of the inductance value L ₀ and the braking capacitance value C ₀ of the secondary coil of the transformer vary widely, the matching frequency F ₀ is made uniform by connecting a matching adjustment capacitor (capacitance value C ₁ ) in parallel. I am doing it.

Next, the difference between the drive voltage waveform and the above embodiment when the vibrating body is disconnected will be described. As for the circuit configuration, in the above embodiment, when the connection of the vibrating body is broken, the capacitance component connected in parallel to the transformer or the inductor connected in parallel to the vibrating body disappears, whereas in this embodiment, the matching adjustment is performed. The capacitor connection for is left. Therefore, a parallel resonance system of the transformer and the matching adjusting capacitor appears due to the disconnection, and the influence appears on the drive voltage waveform.

FIG. 18 shows a change in the frequency characteristic of the amplitude of the drive voltage when the connection of the vibrating body of the vibrating actuator 27 of FIG. 17 is disconnected. The frequency is swept and the amplitude of the drive voltage is measured on the assumption that the rectangular voltage generating means 12 outputs a sine wave.

The solid line is the case where there is no disconnection, the broken line is the case where one vibrating body is broken, the alternate long and short dash line is the case where the two vibrating bodies are broken, and the dotted line is all broken. F ₁ is the frequency of the fundamental wave of a certain drive voltage waveform used in normal driving, F ₂ is the frequency of the second harmonic, F ₃ is the frequency of the third harmonic, and F ₄ is the frequency of the fourth harmonic. Shows. The peak characteristic between the frequency F3 of the _third harmonic and the frequency F4 of the _fourth harmonic is the effect of the parallel resonance of the matching adjusting capacitor and the transformer caused by the disconnection of the vibrating body. Moreover, since the frequency F3 of the _third harmonic of the drive voltage is near the frequency (around 310 kHz) of the lowest point of the valley of the frequency characteristic when there is no disconnection, the amplitude of the third harmonic is large at the time of disconnection. Since it is changing, the waveform change at the time of disconnection is increased.

FIG. 19 shows a drive voltage waveform when the rectangular voltage generating means 12 outputs a pulse signal having a duty of 50%. The solid line is the case where there is no disconnection, the broken line is the case where one vibrating body is broken, the alternate long and short dash line is the case where the two vibrating bodies are broken, and the dotted line is all broken. It can be seen that when a disconnection occurs, the sine wave approaches a rectangular wave as the number of disconnections increases.

FIG. 20 shows an example of the waveform analysis result of the drive voltage by the drive signal analysis means 18 when the duty of the pulse signal output by the rectangular voltage generation means 12 is 50%. FIG. 20 (a) shows the waveform factor, FIG. 20 (b) shows the effective value- "the average value of the absolute values", and FIG. 20 (c) shows the total harmonic distortion (the amplitude of the harmonic component other than the fundamental wave is the fundamental wave). (Value divided by the amplitude of), FIG. 20 (d) is a graph showing the value obtained by dividing the amplitude of the third harmonic by the amplitude of the fundamental wave. In all the waveform analysis results of FIG. 20, the gap between the disconnection 0 and the disconnection 1 is wide, and it is easy to determine the presence or absence of the disconnection. The long chain line in FIG. 20 shows a threshold value for determining the presence or absence of disconnection during driving of the vibrating actuator 27. The reason why the gap is widened is that the frequency characteristic of the drive voltage amplitude in FIG. 18 changes due to the presence or absence of disconnection near the third harmonic (F ₃ ) due to the influence of the parallel resonance of the matching adjustment capacitor and the transformer. Because it is big. By setting the frequency of parallel resonance by the matching adjustment capacitor and the transformer in the vicinity of the low-order harmonics of the pulse signal in this way, it is possible to easily determine the presence or absence of disconnection.

Further, as in the above embodiment, by measuring the characteristics of the amplitude of the drive voltage generated by the disconnection in advance and creating a comparison table of the analysis results, the analysis results and the comparison table can be used while the vibration type actuator 27 is being driven. It is possible to determine the presence or absence of disconnection and the number of disconnections.

FIG. 21 is a diagram showing a second example of the drive circuit of the vibration type actuator of the second embodiment. In the example shown in FIG. 17, the transformers 5, 6 and 7 and the matching adjusting capacitors 24, 25 and 26 are connected in parallel to the vibrating bodies 1, 2 and 3, whereas the vibrating bodies 1, 2 and 3 are connected in parallel. The inductors 20, 21 and 22 and the matching adjusting capacitors 24, 25 and 26 are connected in parallel. The matching adjustment capacitors 24, 25, and 26 are mounted on a circuit board (not shown) adjacent to the inductors 20, 21, and 22, and the vibrating bodies 1, 2, and 3 are flexible boards connected to the circuit board via a connector. Be connected. The risk of disconnection of the flexible substrate increases in applications where the flexible substrate is repeatedly bent or bent.

Assuming that the matching frequency is F ₀ , the braking capacitance value is C ₀ , and the inductor inductance value is L ₀ , the capacitance value C ₁ of the matching adjusting capacitor is expressed by Equation 2. The parallel series circuit of the vibrating bodies 1, 2, 3 and the inductors 20, 21, 22 and the matching adjusting capacitors 24, 25, 26 constitutes the vibrating actuator 28, and the pulse signal of the rectangular voltage generating means 12 has a waveform. It is applied via the shaping means 11. The current flowing through the vibration type actuator 28 is converted into a voltage signal by the resistance 13 and input to the amplitude detecting means 14. Since the operation of each part is the same as that of the first embodiment, the description thereof will be omitted.

In addition, as the number of vibrating bodies connected in series increases, the risk of poor connector insertion during manufacturing also increases. Poor insertion is also a type of disconnection, and the analysis result changes from disconnection 0 to disconnection 1 during the period from poor contact to complete disconnection (disconnection) of the connector. In the process of the change, the analysis result crosses the threshold value, and it is possible to detect a connector insertion failure or the like.

Further, in the above description, the four waveform analysis methods have been used, but any method can be used as long as the output changes depending on the waveform.

In the above description, the pulse signal which is the output of the rectangular voltage generation means 12 is used as the drive voltage, but other waveforms may be used. Even if it is a triangular wave, a sawtooth wave, or a PWM modulated wave that is the output of a known class D amplifier, if the waveform contains many relatively low-order harmonics of the 5th or lower order, the waveform change due to disconnection is relatively large. It can be used to detect disconnection.

FIG. 22 is a diagram showing the configuration of the vibrating body used in the third embodiment. FIG. 48 in FIG. 22A is a rectangular elastic body made of a conductive material, and has two protrusions on the surface that come into contact with the contact body. 49 is a part of the elastic body 48, and is a piezoelectric body for vibrating the elastic body 48. FIG. 22B shows an electrode provided on the piezoelectric body 49, and the electrodes 31 and 32 are electrically insulated from each other, and two AC voltages whose phases change independently are applied. The entire back surface of the piezoelectric body 49 is an electrode, and is configured to be energized from the front surface through vias (not shown) provided on a part of the electrodes 31 and 32.

FIG. 23 is a diagram showing a vibration mode of the elastic body 48. FIG. 23 (a) shows a vibration mode (push-up vibration mode) excited when an AC voltage of the same phase is applied to the electrodes 31 and 32, and FIG. 23 (b) shows an AC voltage of the opposite phase. It is a vibration form of a vibration mode (feed vibration mode) that is excited when applied.

That is, when the phase difference of the applied AC voltage is 0 °, the mode of FIG. 23 (a) is excited, and when the phase difference is 180 °, the mode of FIG. 23 (b) is excited. Further, when the phase difference of the AC voltage is set between 0 ° and 180 ° (actually, about 0 ° to 120 ° is used), both vibration modes are excited at the same time, and the protrusions provided on the elastic body 48 are excited. The contact body in pressure contact moves in the longitudinal direction of the rectangle of the elastic body 48.

FIG. 24 is a diagram showing a configuration of a direct-acting vibration type actuator of this embodiment. Specifically, the protrusions of the vibrating bodies 36 and 37 are arranged vertically facing each other, and similarly, 5 sets of vibrating bodies are arranged in pairs up and down up to the vibrating body 38 on a straight line, for a total of 10 vibrating bodies. It is configured to sandwich the common contact body 50 from the vertical direction and move in the direction of the arrow.

FIG. 25 is a diagram showing a drive circuit of the vibration type actuator of the third embodiment. The number of vibrating bodies of the vibrating actuators of the first and second embodiments was three and the number of phases of the driving voltage was one, but in this embodiment, the number of vibrating bodies is ten and the driving voltage of two phases. Driven by. In the ten vibrating bodies 36, 37, ..., 38, a conductive elastic body (not shown) is connected to the ground potential.

The vibrating body 36 is provided with electrodes 30 and 31 provided on the piezoelectric body 49, and is connected to the transformers 32 and 33 together with the matching adjusting capacitors 34 and 35 in parallel, respectively. The primary side of the nine transformers 52, ..., 53 is connected in series to the primary side of the transformer 32, and the nine vibrating bodies 37, ..., 38 are connected to the secondary sides of the transformers 52, ..., 53, respectively. One electrode of the vibrating body is connected in parallel. Similarly, nine transformers 54, ..., 55 are connected in series to the primary side of the transformer 33, and the vibrating bodies 37, ..., 38 9 are connected to the secondary sides of the transformers 54, ..., 55, respectively. The other electrodes of the vibrating bodies are connected in parallel. Further, a matching adjusting capacitor is connected in parallel with a transformer to the 10 vibrating bodies 36, 37, ..., 38, and vibration is performed by 10 sets of units connected in series including these vibrating bodies, a matching adjusting capacitor, and a transformer. It constitutes a type actuator 51.

Reference numeral 40 denotes a rectangular voltage generating means for outputting a two-phase pulse signal, and a driving voltage is applied to the vibration type actuator 51 via the waveform shaping means 11 and 39 composed of a series circuit of an inductor and a capacitor. 41 and 42 are resistors for measuring the two-phase currents flowing through the vibrating actuator 51, respectively, and detect voltages proportional to the vibration speeds of the vibrating bodies 36, 37, ..., 38.

Reference numeral 43 denotes an A / D converter for detecting the vibration speed detected by the resistors 41 and 42, and a two-phase current signal (CurA, CurB) is input to the CPU 15 as time series data. The CPU 15 determines a position command, a pulse width command, and a frequency command based on a position command from a command means (not shown), a two-phase current signal from the A / D converter 43, and an analysis result of a drive signal analysis means 47 described later. And output. The pulse width command and the frequency command are input to the rectangular voltage generating means 40, and the frequency and the pulse width of the two-phase pulse signal to be output are set. A detailed description of the operation of the CPU 15 will be described later.

Reference numeral 45 is a known linear encoder for detecting the position of the common contact body 50, and 46 is a position comparison means for outputting the difference between the position command from the CPU 15 and the position signal output by the linear encoder 45. Reference numeral 44 denotes a position control means for outputting a phase difference command to the rectangular voltage generation means 40 according to the output of the position comparison means 46, and setting the phase difference of the two-phase pulse signals to move the moving direction and speed of the contact body 50. Is in control. Reference numeral 47 denotes a drive signal analysis means for analyzing the waveform of the two-phase drive voltage of the vibration type actuator 51, performing waveform analysis of the two-phase drive voltage and outputting the analysis result.

FIG. 26 shows a change in the frequency characteristic of the amplitude of the drive voltage when the connection of the vibrating body of the vibrating actuator 51 of FIG. 25 is disconnected. The frequency is swept and the amplitude of the drive voltage is measured on the assumption that the rectangular voltage generating means 40 outputs a sine wave. The solid line shows the characteristics without disconnection, and the dotted line shows the characteristics with the number of disconnections from 1 to 10. F ₁ indicates the frequency of the fundamental wave of a certain drive voltage during normal driving, and F ₂ , F ₃ , F ₄ , and F ₅ indicate the frequencies of harmonics from the second order to the fifth order. Comparing the voltage amplitudes of the frequencies of each harmonic order in FIG. 26, it can be seen that the ratio of the amplitudes between the orders differs depending on the number of disconnections, and the waveform changes. In particular, it is shown that the change in the drive voltage amplitude is large depending on the presence or absence of disconnection near the frequency (F ₃ ) of the third harmonic. Further, since the frequency F3 of the _third harmonic of the drive voltage is near the frequency (near 290 kHz) of the lowest point of the valley of the frequency characteristic when there is no disconnection, the amplitude of the third harmonic is large at the time of disconnection. Since it is changing, the waveform change at the time of disconnection is increased.

FIG. 27 shows the change in the waveform of the drive voltage. The solid line is the case where there is no disconnection, the broken line is the case where one vibrating body is broken, the alternate long and short dash line is the case where the two vibrating bodies are broken, and the dotted line is all broken. It can be seen that when a disconnection occurs, the apex of the sine wave collapses, and the sine wave approaches a square wave as the number of disconnections increases.

FIG. 28 shows an example of the waveform analysis result of the drive voltage by the drive signal analysis means 47 when the duty of the pulse signal output by the rectangular voltage generation means 40 is 50%. 28 (a) shows the waveform factor (mean value / effective value of absolute value), FIG. 28 (b) shows the effective value- (mean value of absolute value), and FIG. 28 (c) shows the total harmonic distortion factor. (D) is a value obtained by dividing the amplitude of the third-order harmonic by the amplitude of the fundamental wave.

In all the waveform analysis results of FIG. 28, the gap between the disconnection 0 and the disconnection 1 is wide, and it is easy to determine the presence or absence of the disconnection. The long chain line in FIG. 28 shows a threshold value for determining the presence or absence of disconnection during driving of the vibrating actuator 51. It can be seen that the presence or absence of disconnection can be sufficiently determined even if only one of the 10 vibrating bodies is disconnected.

Here, the detailed operation of the CPU 15 will be described with reference to the flowchart. The CPU 15 controls the vibration amplitude control based on the two-phase current signal from the A / D converter 43, and controls the operation such as driving / stopping of the vibration type actuator 51 based on the waveform analysis result of the drive signal analysis means 47. .. First, operations such as driving and stopping of the vibration type actuator 51 based on the waveform analysis result will be described.

The control method of the vibration type drive device according to this embodiment is as follows. That is, the control unit outputs a command signal to the drive unit, and the drive signal output by the drive unit vibrates the vibrating body unit in which two or more vibrating bodies are connected. At the same time, the drive signal is analyzed, the analysis result is output, and based on the analysis result, it is determined whether or not the wiring connected to the vibrating body is broken.

FIG. 29 is a flowchart showing an example of the operation of the CPU 15 that executes different drive sequences of the vibration type actuator 51 depending on the disconnection result. The sequence of the position control operation of the contact body 50 is shown, different operation sequences are selected depending on the number of disconnections (N), and each operation sequence will be described with reference to a flowchart. The position control operation starts when a new position command POS_C is input from a command means (not shown). First, check the number of disconnection N of the oscillator that has occurred so far. If the number of disconnections N is 2 or more, the LED for displaying the disconnection status is lit in red to end the position control operation. If the number of disconnections N is 1 or less, the pulse width command PW_C is set to the predetermined pulse width PW0 and the frequency command _Frq is set to the initial frequency F0 in order to generate the drive voltage applied to the vibrating actuator 51. Then, the amplitude command AMP_C is set to a predetermined amplitude AMP0, and the drive timer T is initialized to 0. Then, a pulse signal is output from the rectangular voltage generating means 40, and the vibration type actuator 51 starts moving. Next, waveform analysis, disconnection determination, and vibration amplitude control are performed. The details of vibration amplitude control will be described later. If the number of disconnections N determined by the disconnection determination is 0, the LED for displaying the disconnection status is lit in green, and waveform analysis, disconnection determination, and vibration amplitude are performed until the drive timer T becomes T1 or the disconnection number N becomes 1 or more. Repeat control. During that time, if the position command POS_C is updated from the command means (not shown), the drive timer T is initialized to 0, and waveform analysis, disconnection determination, and vibration amplitude control are repeated until the drive timer T becomes T1. When the drive timer T becomes T1, the pulse width command PW_C is set to 0, the vibration amplitude command AMP_C is also set to 0, and the position control operation is terminated.

If the number of disconnections N becomes 1 or more before the drive timer T becomes T1, different operations are executed depending on the number of disconnections N. If the number of disconnections N is 1, the LED for displaying the disconnection status is turned on in yellow, and the same operation as when the number of disconnections N is 0 is continued. If the number of disconnections N is 2, the LED for displaying the disconnection status is lit in orange, and the position command POS_C is not updated, but the same operation as when the number of disconnections N is 0 is continued until the drive timer T reaches T1. If the number of disconnections N is 3 or more, the LED for displaying the disconnection state is turned on in red, the pulse width command PW_C is set to 0, and the vibration amplitude command AMP_C is also set to 0 to end the position control operation.

A vibrating actuator such as the vibrating actuator 51 in which a plurality of vibrating body units are connected in series may be able to continue driving even if some vibrating bodies are disconnected, so that driving may be continued depending on the application. .. In addition, even if the number of disconnections is small, damage will accumulate in the peripheral mechanism if driving is continued, so even if driving is continued, if the cumulative driving time exceeds a certain level, driving may be prohibited. ..

Next, the operations of waveform analysis, disconnection determination, and vibration amplitude control will be described.

FIG. 30 is a flowchart of waveform analysis, disconnection determination, and vibration amplitude control operation. First, the two-phase time-series current signals CurA (t) and CurB (t) separately input from the A / D converter 43 by interrupt processing are added to generate the signal Cur (t). This corresponds to the vibration velocity (vibration amplitude) of the push-up vibration mode of the vibrating body. Next, a first-order (fundamental wave) signal is extracted by a low-pass filter operation to obtain a first-order amplitude Amp (1). Next, the number of breaks in each of the two phases is obtained from the analysis result (for example, waveform ratio) based on the analysis method of FIG. 28 input from the drive signal analysis means 47, and the total number of breaks N is obtained. Next, the vibration amplitude command Amp_C and the first-order amplitude Amp (1) are compared, and if Amp (1) is smaller than Amp_C, the frequency is set lower by dF from the frequency command Frq. If Amp (1) is larger than Amp_C, the frequency is set higher by dF in the frequency command Frq. Further, the frequency command is limited to be within the minimum frequency Frq_min and the maximum frequency Frq_max.

In this way, the vibration amplitude of the push-up vibration mode of the vibration type actuator 51 is controlled by the vibration amplitude command Amp_C, and the contact state between the contact body 50 and the vibrating body is maintained in a desired state. In this embodiment, the waveform analysis of the two-phase drive voltage is performed individually, but the waveform analysis may be performed based on the signal to which the drive voltage is added.

Further, in the above description, the four waveform analysis methods have been used, but any method can be used as long as the output changes depending on the waveform.

In the above description, the pulse signal which is the output of the rectangular voltage generation means 12 is used as the drive voltage, but other waveforms may be used. Even if it is a triangular wave, a sawtooth wave, or a PWM modulated wave that is the output of a known class D amplifier, if the waveform contains many relatively low-order harmonics of the 5th or lower order, the waveform change due to disconnection is relatively large. It can be used to detect disconnection.

In the above embodiment, the disconnection of the vibrating body of the vibrating actuator is detected by analyzing the waveform of the drive voltage, but the disconnection can also be detected by analyzing the waveform of the inflow current to the vibrating actuator. In FIG. 31, the drive signal analysis means 47 of the drive circuit of the vibration type actuator of FIG. 25 is modified so as to analyze the waveform of the terminal voltage (inflow current to the vibration type actuator) of the resistors 41 and 42 instead of the drive voltage. be. Since the description of the operation of each part is the same as that of the third embodiment, the description is omitted and the waveform analysis operation will be described.

FIG. 32 shows a change in the frequency characteristic of the amplitude of the terminal voltage (current flowing into the vibrating actuator) of the resistor 41 or the resistor 42 when the connection of the vibrating body of the vibrating actuator 51 of FIG. 31 is disconnected. The solid line shows the characteristics without disconnection, and the dotted line shows the characteristics with the number of disconnections from 1 to 10. F ₁ indicates the frequency of the fundamental wave of a certain drive voltage waveform during normal driving, and F ₂ , F ₃ , F ₄ , and F ₅ indicate the frequencies of harmonics from the second order to the fifth order. Comparing the amplitudes of the inflow currents at the frequencies of each harmonic order in FIG. 32, it can be seen that the amplitude ratio between the orders differs depending on the number of disconnections and the waveform changes. In particular, it is shown that the change in the inflow current amplitude is large depending on the presence or absence of disconnection near the frequency (F ₃ ) of the third harmonic. Compared with the characteristics of the drive voltage amplitude in FIG. 26, the characteristic is the negative peak characteristic that matches regardless of the number of disconnections near 310 kHz. This is caused by the parallel resonance of the secondary side of the transformer connected in parallel with the vibrating body and the matching adjusting capacitor.

FIG. 33 shows an example of the waveform analysis result of the inflow current to the vibration type actuator 51 by the drive signal analysis means 47 when the duty of the pulse signal output by the rectangular voltage generation means 40 is 50%. 33 (a) is the waveform factor (mean value / effective value of absolute value), FIG. 33 (b) is the effective value- (mean value of absolute value), FIG. 33 (c) is the total harmonic distortion factor, and FIG. 33. (D) is a value obtained by dividing the amplitude of the third-order harmonic by the amplitude of the fundamental wave.

Although it is possible to determine the presence or absence of disconnection between disconnection 0 and disconnection 1 in all the waveform analysis results of FIG. 33, the value of the analysis result changes greatly depending on the frequency, so it is necessary to change the threshold value for disconnection determination depending on the drive frequency. be. It is necessary to measure the characteristics of the amplitude of the inflow current to the vibrating actuator generated by the disconnection in advance and create a comparison table of the analysis results. By doing so, it is possible to determine the presence or absence of disconnection and the number of disconnections by using the analysis result and the comparison table while driving the vibration type actuator 51 as in the above embodiment.

The operation of the CPU 15 that controls drive / stop in different sequences according to the disconnection result follows the flowchart of FIG. 29 and is the same as the above description, so the description thereof will be omitted.

Next, the operations of waveform analysis, disconnection determination, and vibration amplitude control will be described. FIG. 34 is a flowchart of waveform analysis, disconnection determination, and vibration amplitude control operation. First, the two-phase time-series current signals CurA (t) and CurB (t) separately input from the A / D converter 43 by interrupt processing are added to generate the signal Cur (t). This corresponds to the vibration velocity (vibration amplitude) of the push-up vibration mode of the vibrating body. Next, the first-order (fundamental wave) and third-order harmonic signals are extracted by bandpass filter calculation to obtain the first-order amplitude Amp (1) and the third-order amplitude Amp (3). Next, Amp (3) / Amp (1) is obtained, and the number of disconnections N is obtained from the relationship between the frequency command Frq and FIG. 31 (d) obtained in advance. Next, the vibration amplitude command Amp_C and the first-order amplitude Amp (1) are compared, and if Amp (1) is smaller than Amp_C, the frequency is set lower by dF from the frequency command Frq. If Amp (1) is larger than Amp_C, the frequency is set higher by dF in the frequency command Frq. Further, the frequency command is limited to be within the minimum frequency Frq_min and the maximum frequency Frq_max. In this way, the vibration amplitude of the push-up vibration mode of the vibration type actuator 51 is controlled by the vibration amplitude command Amp_C.

As described above, in this embodiment, since the current signal flowing through the vibration type actuator 51 is used for both the vibration amplitude control and the disconnection analysis, the circuit scale can be reduced.

As described above, the analysis result is the result of analyzing the waveform of the drive voltage or the waveform of the current flowing into the vibrating body unit.

Further, in the above description, the four waveform analysis methods have been used, but any method can be used as long as the output changes depending on the waveform.

Further, in the above description, it is assumed that the piezoelectric body is bonded to the vibrating body, but the vibrating body itself may be constructed of the piezoelectric body. Further, the piezoelectric body may be a laminated piezoelectric body.

The above-mentioned vibration type drive device can be applied to various devices.

1, 2, 3, 36, 37, 38, 48 Vibrating body 4 Cylindrical shaft 5, 6, 7, 32, 33, 52, 53, 54, 55 Transformer 10, 23, 27, 28, 51 Vibration type actuator 11, 19 Waveform shaping means 12, 40 Rectangular voltage generating means 13, 41, 42 Resistance 14 Vibration detecting means 15 CPU
16 Amplitude comparison means 17 Amplitude control means 18, 39, 47 Drive signal analysis means 20, 21, 22 Inductors 24, 25, 26, 34, 35 Matching adjustment capacitors 43 A / D converter 44 Position control means 46 Position comparison means 49 Piezoelectric body 50 Common contact body

Claims (22)

A control unit that outputs a command signal and
A drive unit that outputs a drive signal based on the command signal,
A vibrating body unit in which two or more vibrating bodies vibrating based on the drive signal are connected,
A vibration type drive device including a drive signal analysis means that analyzes the drive signal and outputs an analysis result, and a determination means that determines whether or not the wiring connected to the vibrating body is broken based on the analysis result. The primary side is provided with the vibrating body unit in which a vibrating body is connected in parallel to the secondary side of a plurality of transformers connected in series, and the driving signal is applied to the primary side of the plurality of transformers. It is composed and
The vibration according to claim 1, wherein the driving unit includes a rectangular voltage generating means for generating a pulse signal having a predetermined voltage and frequency, and a waveform shaping means inserted between the rectangular voltage generating means and the vibrating body unit. Type drive device. A pair of inductors and a vibrating body connected in parallel are provided with the vibrating body unit in which a plurality of pairs are connected in series.
The vibration according to claim 1, wherein the driving unit includes a rectangular voltage generating means for generating a pulse signal having a predetermined voltage and frequency, and a waveform shaping means inserted between the rectangular voltage generating means and the vibrating body unit. Type drive device. The drive signal analysis means analyzes the waveform of the output voltage or output current of the waveform shaping means, and responds to any of the waveform rate, the harmonic distortion rate, the difference between the effective value and the average value of the absolute value, and the harmonic amplitude. The vibration type drive device according to claim 2 or 3, wherein the value is detected. 2. The vibration type drive device according to any one of 4 to 4. The vibration type drive device according to any one of claims 2 to 5, wherein the waveform shaping means is a series circuit of an inductor and a capacitor or an inductor. The vibration type drive device according to claim 2, wherein a capacitor is further connected in parallel with the inductor. The vibration type drive device according to claim 3, wherein a capacitor is connected in parallel on the secondary side of the transformer. The vibration type drive device according to any one of claims 1 to 8, wherein the determination means determines the presence or absence of disconnection by a predetermined threshold value. The vibration type drive device according to any one of claims 1 to 8, wherein the determination means determines the number of disconnections based on a table of analysis results obtained in advance according to the number of disconnections. The vibration type drive device according to any one of claims 1 to 9, which has a common contact body in contact with the vibrating body unit. The vibrating drive device according to claim 11, wherein the contact body is a cylindrical shaft and includes three vibrating bodies arranged substantially evenly on the circumference of the cylindrical shaft. The vibrating drive device according to claim 11 or 12, further comprising a hollow case for accommodating the contact body and the vibrating body. The vibrating drive device according to any one of claims 1 to 13, wherein the vibrating body includes a rectangular elastic body having two protrusions and a piezoelectric body. The control unit outputs a command signal to the drive unit, and the vibrating body unit in which two or more vibrating bodies are connected vibrates by the drive signal output by the drive unit based on the command signal, and the drive signal is analyzed and analyzed. A control method for a vibrating drive device that outputs a result and determines whether or not the wiring connected to the vibrating body is broken based on the analysis result. In the vibrating body unit, a vibrating body is connected in parallel to each of the secondary sides of a plurality of transformers to which the primary side is connected in series, and the driving signal is applied to the primary side of the plurality of transformers. It is composed and
The vibration according to claim 15, wherein the driving unit includes a rectangular voltage generating means for generating a pulse signal having a predetermined voltage and frequency, and a waveform shaping means inserted between the rectangular voltage generating means and the vibrating body unit. Control method of type drive device. The vibrating body unit is configured such that a pair of inductors connected in parallel and a vibrating body are connected in series in a plurality of pairs.
The vibration according to claim 15, wherein the driving unit includes a rectangular voltage generating means for generating a pulse signal having a predetermined voltage and frequency, and a waveform shaping means inserted between the rectangular voltage generating means and the vibrating body unit. Control method of type drive device. The control method for a vibration-type drive device according to any one of claims 15 to 17, wherein a different drive sequence is executed depending on the number of broken wires of the wiring connected to the vibrating body. The control method for a vibration type drive device according to claim 18, wherein the LED for displaying the disconnection state is turned on according to the number of disconnections. The vibration type drive device according to any one of claims 15 to 19, wherein the analysis result is the result of analyzing the waveform of the drive voltage or the waveform of the current flowing into the vibrating body unit as the drive signal. Control method. The vibration type drive device according to claim 20, wherein the waveform is a waveform of an average value of the absolute values of the drive voltage with respect to the frequency of the drive voltage, or a waveform of an effective value of the drive voltage with respect to the frequency of the drive voltage. Control method. The control method for a vibration-type drive device according to claim 20, wherein the waveform is a waveform of a third-order harmonic amplitude and a fundamental wave amplitude with respect to the frequency of the drive voltage.

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