TW201943625A - Control device of vibration system, and workpiece conveying device providing stable and high efficient driving by means of vibration of parts feeder or ultrasonic motor - Google Patents

Abstract

The present invention provides a control device of a vibration system that is applied to a device using a vibration of a parts feeder or an ultrasonic motor, and that is stable and high efficient driving. The control device of the vibration system of the present invention is used when two vibration systems (1, 2) having different resonance frequencies (f1, f2) are driven by a common drive command, and includes: a first amplitude detector (61) and a second amplitude detector (62) that detect the amplitude of vibration of each vibration system (1, 2); a differentiator (63) for comparing the detected amplitudes by means of the amplitude means (61,62); and a tracing means (7) for tracing the frequency (f) of the drive command in such a way that the deviation between the two amplitudes obtained by the differentiator (63) becomes zero.

Description

Control device of vibration system and workpiece conveying device

The present invention relates to a control device and a workpiece conveying device that are suitable for a device that uses vibrations such as a component feeder, an ultrasonic motor, and the like, and can stably and efficiently perform such a driven vibration system.

A device having a plurality of vibration systems such as an elliptical vibrating part feeder, a traveling wave type part feeder, an ultrasonic motor, and the like, which have been driven at a single frequency, is known from the past. . Here, the plural vibration system refers to any one of a vibration system obtained by a plurality of structures, a vibration system having a plurality of vibration directions, and a plurality of vibration modes of the same structure.

In the device shown above, in order to vibrate the conveying section efficiently, the resonance frequency of the complex vibration system is often designed and adjusted so that the resonance frequency of the plurality of vibration systems becomes close to the drive frequency. In addition, there has been proposed a control for adjusting a driving frequency in accordance with a resonance frequency of one vibration system among a plurality of vibration systems (see, for example, Patent Documents 1 and 2).

Patent Document 1 shows a driving circuit of an ultrasonic motor, which is configured by a voltage according to a driving state (a voltage obtained by driving a piezoelectric element for detection) and a voltage applied to a piezoelectric body (of two electrodes). The driving frequency is controlled such that the phase difference of one of the applied voltages becomes a predetermined phase difference.

On the other hand, Patent Document 2 shows a drive control device for an elliptical vibration component feeder configured to set an output frequency such that the amplitude of either the horizontal vibration or the vertical vibration becomes maximum. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 07-2023 [Patent Document 2] Japanese Patent Publication No. 11-227926

(Problems to be solved by the invention)

However, in the present invention, the elliptical vibration component feeder or the traveling wave type component feeder are generally shifted at the resonance frequencies of the two vibration systems. In particular, in the traveling wave type part feeder, two standing wave modes with a spatial phase shift of 90 ° are used. However, since the vibration part is asymmetrical, it is easy to shift the resonance frequency, and it is difficult to match them. Adjustment. In addition, it has been confirmed that the resonance frequency changes depending on changes in temperature and the like. At this time, it is considered that the resonance frequency of each vibration system does not necessarily change in the same manner, and the offset may increase.

Therefore, in the control for adjusting the driving frequency based on the resonance frequency of a conventional vibration system, the overall efficiency of the device will not be maximized due to the influence of the deviation of the resonance frequency. In addition, the difference in the response magnification of the vibration of each vibration system becomes large, and it is considered that problems such as an excessively large excitation force being necessary for a required amplitude to appear in a part of the vibration system, or insufficient amplitude in some of the vibration system may occur.

The present invention has been accomplished by focusing on the problems as described above, and aims to achieve tracking of the resonance frequency of one vibration system instead of the conventional one. The response magnification of the vibration between the resonance frequencies of the two vibration systems is approximated. A control device for a vibration system and a workpiece conveying device that perform control by driving at equal frequencies to achieve problem solving. (Means for solving problems)

To solve this problem, the present invention adopts the following means.

That is, the control device of the vibration system of the present invention is a control device used when two vibration systems having different resonance frequencies are driven by a common driving command, and is characterized in that it includes: A means for detecting the amplitude of vibration; a means for comparing the amplitudes detected by the means for detecting the amplitude; and a frequency of the drive command such that the deviation between the two amplitudes obtained by the means for comparison becomes zero. Means of tracing.

With the control shown above, the two vibration systems can be driven at frequencies with approximately the same amplitude. This frequency is between the resonance frequencies of the two vibration systems. Therefore, compared with the control of adjusting the driving frequency based on the resonance frequency of one vibration system, the difference in the response magnification of the vibration of each vibration system becomes smaller. A part of the vibration system requires an excessively large excitation force, or a part of the vibration system has insufficient amplitude, so that the entire device can be efficiently controlled. In addition, since the control is performed only where the amplitudes match, the control is also simpler than the case where the resonance frequency is explored using the phase difference between the drive command and the response of the vibration system.

In this case, it is preferable that the tracking means includes: a control amount calculation unit that calculates a control amount using at least a proportional term and an integral term based on the deviation of the amplitude obtained through the comparison means; and The aforementioned frequency regulator is a frequency regulator that increases or decreases the frequency.

If the amplitudes match, the frequency is not adjusted. On the other hand, the larger the deviation of the amplitude, the more it deviates from the frequency with the same amplitude, so the amount of adjustment of the frequency becomes larger in accordance with the deviation. Then, by including the control of the proportional term and the integral term, the target value can be reached quickly.

In addition, it is more preferable to include a gain multiplying section that multiplies a drive command input to one of the two vibration systems by a gain, and divides the detection signal detected by the amplitude detection means of the vibration system by the foregoing. The gain division unit of the gain, and the detection signal calculated by the gain division unit is input to the comparator.

As described above, the present invention can be applied to two vibration systems having relatively large amplitudes, such as an elliptical vibration system, or the purpose of correcting mechanical errors such as a traveling wave component feeder to make the amplitudes consistent, etc. The common drive command causes the two vibration systems to vibrate at an appropriate amplitude based on the same frequency. Furthermore, since one of the signals detected by the amplitude detection means is divided by the gain to compare the deviations, the two vibration systems can be adjusted to achieve a balanced frequency.

In addition, it is more suitable to include a gain division unit that divides the detection signal detected by the amplitude detection means of one of the two vibration systems described above by the gain, and the detection signal calculated by the gain division unit is input. To the aforementioned comparator.

If the configuration is as shown above, the magnitude of the boosting signal is equal in the two vibration systems, and it is driven at a frequency at which the response magnification becomes a predetermined ratio, whereby the amplitude ratio also becomes a predetermined ratio. At this time, the amplitudes of the excitation signals to the two vibration systems can be made equal regardless of the set value of the amplitude ratio, so that the operation of the amplifier such as the driver is stable.

Next, it is more suitable to include a conveying section that conveys the workpiece while it is placed, and a traveling wave that is generated by two standing waves with different phases and used to cause the traveling section to generate a deflection vibration. The wave generating means applies the control device of the vibration system described above to the generation of the two standing waves of the traveling wave generating means to constitute a workpiece transfer device.

If it is a workpiece conveying device as described above, a traveling wave is appropriately generated from two standing waves, and efficient conveyance is possible.

Alternatively, it is more suitable to include a conveying section that conveys the workpiece while it is being placed, and a combination of two vibrations including the conveying direction and the direction of a vertical component that intersects the conveying direction to synthesize the conveying section The elliptical vibration generating means that performs elliptical vibration applies a control device of the vibration system described above to the generation of the two vibrations of the elliptical vibration generating means to configure a workpiece transfer device.

If it is a workpiece conveying device as described above, elliptical vibration is appropriately generated from two vibrations, and efficient conveyance is possible. (Effect of the invention)

According to the present invention described above, it is possible to provide a novel and useful control system for a vibratory system capable of driving such a stable and high-efficiency drive and a workpiece transfer if it is applied to a component feeder or a device using vibration such as an ultrasonic motor. Device.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a control device C of the vibration system of this embodiment. This control device C is provided with the first and second vibration systems 1 and 2 and has vibration units (1x, 2x) at which the resonance frequencies f1 and f2 of the vibration systems 1 and 2 are close to each other. As an example of a vibration system in which the resonance frequencies f1 and f2 are close to each other as shown above, for example, a complex portion having a phase difference in space is vibrated in a complex vibration mode, thereby advancing a component in which a traveling wave occurs. Ultrasonic vibration systems such as feeders, or spring-mass damper vibration systems, such as flat conveying devices that generate elliptical vibrations by vibrating in the XZ or YZ direction.

Specifically, the first and second vibration systems 1 and 2 are vibrated by first and second vibrators 11, 21, respectively.

For the first and second vibrators 11, 21, the frequency generated by the drive command generating section 3 such as a transmitter is variable and periodic signals such as a sine wave or a rectangular wave are applied to the first and second amplifiers 12, 22. Zoom in and enter. The frequency of the driving command generated by the driving command generating unit 3 is externally variable. The amplification factors of the amplifiers 12 and 22 are assumed to be equal. Regarding the second vibrator 21, in order to provide a relative phase difference to the second vibrating system 2 using the first vibrating system 1 as a reference, a periodic signal from the drive command generating section 3 is input to be shifted in the phase shifter 4 The phase is amplified by the second amplifier 22.

That is, the periodic signal from the drive command generating section 3 is input to the first amplifier 12 and is input to the second amplifier 22 by the phase shifter 4 being out of phase.

Here, if it is a general control, the drive command generating unit 3 is configured to generate a drive command at any frequency of the resonance frequency f1 of the first vibration system 1 or the resonance frequency f2 of the second vibration system 2 and use a phase shifter. 4 A 90 ° phase difference is added to drive the two vibration systems 1, 2.

However, as described above, the entire control is driven by the resonance frequency f1 of the first vibration system 1, and the second vibration system 2 is formed so as not to be driven at the resonance frequency f2. Therefore, between the first vibration system 1 and the first vibration system 1, The difference in response magnification becomes large, and it is considered that various problems such as an excessively large excitation force or insufficient amplitude must be generated in the second amplifier 22 in order to generate a required amplitude in the second vibration system 2. This is also the case when the whole is driven at the resonance frequency f2 of the second vibration system 2.

Therefore, this embodiment is provided with: the first vibration detector 51 and the second vibration detector 52 as the vibration detection means for detecting the vibration of the aforementioned vibration systems 1 and 2; and detected by the vibration detectors 51 and 52. The first amplitude detector 61 and the second amplitude detector 62 used as the amplitude detection means of the detected amplitude of the obtained vibration signal; and the difference which is the comparison means by comparing the amplitudes detected by the amplitude detectors 61 and 62. And a tracking means 7 that tracks the frequency of the driving command in the driving command generating unit 3 so that the deviation between the two amplitudes obtained by the comparing means 63 becomes zero.

At this time, the first and second vibration detectors 51 and 52 detect: the displacement signals, the speed signals, or the acceleration signals from each other by the vibration parts 1x, 2x of the first and second vibration systems 1, 2; Any of them.

The tracking means 7 is configured to include a PI control unit 71 that calculates a control amount Δf as a control amount calculation unit based on a deviation of the amplitude obtained through the differentiator 63 using at least a proportional term and an integral term; and a corresponding one of the positive and negative deviations. In the direction, the frequency adjuster 72 is used to increase or decrease the frequency f by the aforementioned control amount Δf.

For example, as shown in FIG. 2, if it is assumed that the resonance frequency f2 of the second vibration system 2 is higher than the resonance frequency f1 of the first vibration system 1, the frequency detected by the second amplitude detector 62 is determined. The magnitude relationship between the amplitude A2 and the amplitude A1 detected by the first amplitude detector 61 is changed as described below.

When A2 <A1 (see FIG. 2 (a)), it is changed to f = f + Δf. When A2> A1 (refer to FIG. 2 (b)), it is changed to f = f-Δf.

Δf is a control value calculated by the PI control unit 72 and is calculated as a larger value as the deviation between the amplitudes of the two vibration systems 1 and 2 becomes larger.

As a result, the frequency of the driving command output by the driving command generating unit 3 is directed to a direction in which the deviation of the amplitudes of the two vibration systems 1 and 2 is set to 0, that is, as shown in FIG. The frequency f0 with the same amplitude is corrected.

At this time, in this embodiment, a gain multiplying unit 81 that generates a gain coefficient Kα in a drive command input to the second vibration system 2 is provided, and a second amplitude detection means 52 is used for the second vibration system 2. The gain division unit 82 that divides the detected detection signal by the aforementioned gain coefficient Kα, inputs the detection signal that is divided by the gain division unit 82 to the differentiator 63.

Accordingly, the amplitude ratio of the first vibration system 1 and the second vibration system 2 becomes 1: Ka. In addition, the output signal from the second amplitude detector 62 is compared with the output signal of the first amplitude detector 61 after being formed at 1 / Kα times. Then, the driving frequency is adjusted so that the deviation becomes zero.

If the configuration is as shown above, for the second vibration system 2, after the command signal is formed as Kα times, the vibration detection value is formed as 1 / Kα times. Therefore, in the signal used for the calculation of the deviation, these gains are cancel. Therefore, at frequencies where the response magnifications are equal, the deviation becomes zero. Therefore, according to the control method of this embodiment, the driving can be performed in response to the frequencies having equal magnifications, that is, the frequencies f between the two resonance frequencies f1 and f2. The frequency f shown above is close to any of the resonance frequencies f1 and f2 of the two vibration systems 1 and 2 and the response rate is high. Therefore, the two vibration systems 1 and 2 can vibrate efficiently. In addition, even if changes in the resonance frequencies f1 and f2 occur, the driving frequency is automatically adjusted in response to this.

As shown above, between the first vibration system 1 and the second vibration system 2, the difference in the response ratio of the vibration becomes smaller, thereby solving the problem that one vibration system must have an excessively large excitation force, or the other Problems such as insufficient amplitude of the vibration system. In addition, as compared with a case where the driving is performed at one resonance frequency, the required electric power is reduced as a whole.

In addition, since the driving frequency is automatically adjusted, the labor for exploring the resonance frequencies f1 and f2 of the first and second vibration systems 1 and 2 by manual operation will disappear. That is, when tracking the resonance frequency, it is not necessary to detect a phase difference or perform a frequency scan, so the detection circuit is simpler and easier to control.

In addition, not only the driving frequency, but also the amplitude ratio of the first vibration system 1 to the second vibration system 2 is controlled to 1: Ka by the gain Kα of the vibration signal. Therefore, the driving state is stable and can be actively set according to the applicable object. Amplitude ratio. If the control to set the amplitude to be constant is performed in parallel, the control may be performed by using the amplitude detection signal of either one of the first and second vibration systems, whereby the amplitude of the other vibration system is also controlled to be constant.

In addition, the tracing means 7 is configured to include a PI control unit 71 that calculates a control amount using at least a proportional term and an integral term based on the deviation of the amplitude obtained through the differentiator 63; and the control amount according to the direction of the deviation. For the Δf part, the frequency adjuster 72 that increases or decreases the frequency, so that the larger the amplitude deviation, the larger the frequency adjustment amount according to the deviation. Then, by including the control of the proportional term and the integral term, it can be made to reach the target value quickly.

Above, for example, like an ultrasonic motor or a traveling wave type component feeder, if the amplitudes of the two vibration modes are expected to be equal, Ka = 1 is set.

FIG. 3 shows an example of frequency response functions of two vibration systems whose resonance frequencies f1 and f2 are shifted. As can be seen from the figure, in the two vibration systems in which the vibration characteristics such as equivalent mass or equivalent rigidity are close, and the resonance frequency is slightly shifted, the graph of the response magnification crosses between the resonance frequencies.

Therefore, the configuration of the present embodiment is particularly effective in a traveling wave type component feeder that is easy to shift in the resonance frequency of the two vibration systems in terms of structure.

FIG. 4 shows a part feeder PF as a workpiece conveying device as an example of the control device C to which the vibration system of the embodiment is applied. The part feeder PF is composed of a bowl feeder Bf that climbs the inserted workpiece along the screw conveying section T1, and conveys the workpieces discharged by the bowl feeder Bf in the entire row. The section t1 performs alignment, orientation determination, and the like, passes only the workpieces in a proper posture, and passes the inappropriate workpieces through the return conveying section t2 to return to the linear feeder Lf of the bowl feeder Bf.

Among them, the bowl-type feeder Bf is shown in FIG. 5 and constitutes a first vibration system that vibrates in the first region and vibrates in a 0 ° mode in a ring-shaped vibration region on the bottom surface of the feeder body. The vibrating part 1x of 1 and the vibrating part 2x of the second vibrating system in the second region that vibrates in the 90 ° mode are vibrated by the first and second vibrators 11 and 21 using a piezoelectric element. Therefore, the traveling wave generating means BZ for generating the traveling wave of the deflection vibration by the transporting portion T1 is synthesized by using standing waves having different phases.

Next, if the above-mentioned control device C is applied to the bowl feeder Bf, if it is configured such that the first and second vibrators 11, 21 of the traveling wave generating means BZ are inputted as shown in Figs. 1 and 2 The first and second amplifiers 12 and 22 are amplified periodic signals. The vibrations of the first and second vibration systems 1 (1x) and 2 (2x) can be taken out through the first and second vibration detectors 51 and 52. . The other parts of the control device C (see FIGS. 1 and 2) are omitted in FIG. 5, and the configuration and control method are the same as those of the above embodiment.

If the part feeder PF shown above is driven, the resonance frequencies f1 and f2 of the vibration units 1x and 2x are considered to be approximately the same, and it is customary to drive. If the piezoelectric elements are stuck to the bottom surfaces of the vibration units 1x and 2x, Due to the heating of the piezoelectric element, the resonance frequency at the complex excitation point is changed by a few percent, and the standing wave ratio is reduced, which may significantly reduce the transport efficiency. However, this problem can be effectively solved by the control through the control device C.

On the other hand, as shown in FIG. 6, the linear feeder Lf of FIG. 4 is configured such that, among the oblong vibration regions on the bottom surface of the feeder body, the first vibration region in the first region vibrates in the 0 ° mode. A vibrating part 1x of a vibrating system 1 and a vibrating part 2x of a second vibrating system in a second region that vibrates in a 90 ° mode pass through a first vibrator 11 and a second vibrator 12 using a piezoelectric element. Vibration is performed to synthesize the standing waves with different phases and use the traveling wave generating means LZ for generating the traveling waves of the deflection vibration of the conveying sections t1 and t2.

Next, if the above-mentioned control device C is applied to the linear feeder Lf, it is also structured such that, in the traveling wave generating means LZ, the first and second vibrators 11, 21 are inputted as shown in Figs. 1 and 2 The first and second amplifiers 12 and 22 are amplified periodic signals. The vibrations of the first and second vibration systems 1 (1x) and 2 (2x) are taken out through the first and second vibration detectors 51 and 52. Just fine. The other parts of the control device C (see FIGS. 1 and 2) are also omitted in FIG. 6, and the configuration and control method are the same as those of the above embodiment.

The embodiment of the present invention has been described above, but the specific configuration of each part is not limited to the embodiment described above.

For example, the control amount calculation unit in the aforementioned embodiment uses PI control. However, it is not limited to this, and various control methods such as matching the sizes of two signals can be adopted.

In addition, the gain Kα may be supplied to the input signal of the first amplifier 12 instead of the second amplifier 22, and the output signal of the first amplitude detector 51 instead of the second amplitude detector 52 may be supplied to the gain 1 / Kα. At this time, the amplitude ratio of the first and second vibration systems 1 and 2 becomes Ka: 1.

In addition, the input signal to the second amplifier 22 as shown in FIG. 7 may not be provided with the gain Kα, and only the output signal of the second amplitude detector 62 may be divided by the gain Kα. At this time, the magnitude of the boosting signal is equal to that of the first and second vibration systems 1, 2 and is driven at a frequency at which the ratio of the response magnification becomes 1: Kα, whereby the amplitude ratio becomes 1: Kα (see FIG. 8). . At this time, since the magnitudes of the vibration signals to the two vibration systems can be made equal regardless of the set value of the amplitude ratio, the operation of the driver (amplifier, etc.) is stable. However, the range of the magnification ratio that can be set depends on the characteristics of the two vibration systems 1 and 2. Therefore, if the resonance frequencies f1 and f2 of the two vibration systems 1 and 2 are close to each other and the difference in response magnification is small at any frequency, the range of the settable amplitude ratio tends to be narrowed.

In addition, FIG. 9 shows an elliptical vibrating part feeder PF as a workpiece conveying device, which is provided with a conveying section tx that conveys the workpiece while it is being placed, and includes a conveying direction (X direction and (Or Y direction) and two vibrations in the direction of the vertical component (Z direction) that intersects the conveying direction, thereby synthesizing the elliptical vibration generating means Pz that causes the conveying section tx to perform elliptical vibration. The elliptical vibration generating means Pz is a first vibration system 1 that vibrates the first plate-shaped spring 11a with a vibrator (piezoelectric element) 11 to vibrate the conveying section tx in the Z direction; and The second plate-shaped spring 21 a is configured by a second vibration system 2 that vibrates with a vibrator (piezoelectric element) 21 to vibrate the transport section tx in the X direction and / or the Y direction. Next, among the two vibration systems 1 and 2 of the elliptical vibration generating means Pz, the vibrator 11 of the first vibration system 1 is vibrated through the first amplifier 12 of FIG. 1, and the second vibration system 2 is vibrated. The vibrator 21 is vibrated through the second amplifier 22 of FIG. 1. If the vibration signals extracted by the vibration systems 1 and 2 through the vibration detectors 51 and 52 are input to the first amplitude detector 61 and FIG. 1, The second amplitude detector 62 can appropriately control the elliptical vibration according to the above.

Various other modifications can be made without departing from the spirit of the present invention.

1‧‧‧The first vibration system

1x, 2x‧‧‧‧Vibration section

2‧‧‧Second vibration system

3‧‧‧Drive command generation unit

4‧‧‧ Phaser

7‧‧‧ Tracking means

11‧‧‧The first vibrator

11a‧‧‧The first leaf spring

12‧‧‧The first amplifier

21‧‧‧Second Exciter

21a‧‧‧Second leaf spring

22‧‧‧Second Amplifier

51‧‧‧Vibration detection means (first vibration detector)

52‧‧‧Vibration detection means (second vibration detector)

61‧‧‧first amplitude detector

62‧‧‧Second Amplitude Detector

63‧‧‧ Comparator (Differential)

71‧‧‧Control amount calculation section (PI control section)

72‧‧‧Frequency Adjustment Department

81‧‧‧Gain Multiplication Division

82‧‧‧Gain Division

f‧‧‧frequency

f1, f2‧‧‧ resonance frequency

BZ, LZ‧‧‧ travelling wave generating means

Pz‧‧‧ Elliptical vibration generating means

PF‧‧‧Workpiece conveying device (part feeder)

T1, t1, t2, tx‧‧‧ transport department

A1, A2‧‧‧amplitude

C‧‧‧control device

Δf‧‧‧Control

Bf‧‧‧ Bowl Feeder

BZ‧‧‧ Traveling Wave Generation Means

Lf‧‧‧ Linear Feeder

LZ‧‧‧ Traveling Wave Generation Means

FIG. 1 is a block diagram showing a control device of a vibration system according to an embodiment of the present invention. FIG. 2 is a graph showing an outline of control in the same embodiment. FIG. 3 is a graph showing an outline of control in the same embodiment. FIG. 4 is a diagram showing a component feeder as a configuration example of a workpiece conveying device of the present invention. FIG. 5 is a control block diagram of a bowl feeder constituting the same-part feeder. Figure 6 is a control block diagram of the linear feeder that constitutes the same part feeder. 7 is a block diagram corresponding to FIG. 1 showing a modified example of the present invention. FIG. 8 is a graph showing an outline of control in the same modification. FIG. 9 is a diagram showing a modified example of the workpiece conveying device of the present invention. Fig. 10 is a graph showing an outline of a conventional control which is compared with the present invention.

Claims (6)

A control device for a vibration system is a control device used when two vibration systems with different resonance frequencies are driven by a common drive command. The control device is characterized by: (1) detecting the vibration amplitude of each of the vibration systems; Amplitude detection means; comparison means for comparing the amplitudes detected by the amplitude detection means; and tracing the frequency of the drive command such that the deviation between the two amplitudes obtained by the comparison means becomes 0 means. For example, the control device of the vibration system of the scope of patent application, wherein the aforementioned tracking means includes: a control amount calculation section that calculates a control amount using at least a proportional term and an integral term based on the deviation of the amplitude obtained through the aforementioned comparison means; And a frequency regulator that increases or decreases the frequency with the aforementioned control amount in the direction of the corresponding deviation. For example, the control device of the vibration system of the first or second scope of the patent application includes: a gain multiplication unit for multiplying a drive command input to one of the two vibration systems by a gain; and The detection signal detected by the amplitude detection means of the vibration system is divided by the gain dividing unit of the gain, and the detection signal calculated by the gain dividing unit is input to the comparator. For example, the control device of the vibration system of the first or second scope of the patent application includes a gain division unit that divides the detection signal detected by the amplitude detection means of either of the two vibration systems described above by the gain, The detection signal calculated by the gain division unit is input to the comparator. A workpiece conveying device, comprising: (1) a conveying section that conveys a workpiece while it is being placed; and (2) a combination of two standing waves with different phases, and used to make the conveying section perform deflection vibration travel The method of generating a traveling wave by wave generation is to apply the control device of the vibration system according to any one of claims 1 to 4 in the generation of the two standing waves of the aforementioned traveling wave generating means. A workpiece conveying device, comprising: (1) a conveying section that conveys a workpiece in a state in which the workpiece is placed; and (2) a combination of two vibrations including a conveying direction and a direction of a vertical component that intersects the conveying direction, so that The conveying unit performs elliptical vibration generating means for elliptical vibration, and the control device of the vibration system according to any one of claims 1 to 4 is applied to the generation of the two vibrations of the elliptical vibration generating means.