JP3890673B2 - Self-excited vibration type vibration device - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a self-excited vibration type vibration device.
[0002]
[Prior art]
In general, a self-excited vibration type vibration device has an advantage of automatically tracking a resonance point. However, the self-excited vibration type vibration device requires some control in order to keep the amplitude of the generated vibration constant. For example, when the actual amplitude is smaller than the command value, the feedback gain is increased to generate self-excited vibration to grow the vibration. When the actual amplitude is larger than the command value, the feedback gain is decreased to reduce the vibration. There is a method of making the amplitude constant by changing the value of the feedback gain, such as attenuating. In this method, the feedback gain is determined according to the detected deviation Δr between the actual amplitude of the vibration device and the amplitude command value.
[0003]
As an example of the self-excited vibration type vibration device, FIG. 10 shows a vibration part feeder 2. FIG. 11 is a block diagram showing the vibration parts feeder 2 which is this self-excited vibration type vibration device by a transfer function. The bowl 10 which is a movable part of the vibration parts feeder 2 has a mass m of acceleration d.² x / dt² When the vibration factor is 1 / s (s is a Laplace transducer—the same applies hereinafter), the velocity is dx / dt, which is multiplied by the viscosity coefficient c, and the vibration damping force is applied to the mass m. Works. Further, when the speed dx / dt passes through the integral element 1 / s, the displacement x is obtained, and the product of this multiplied by the spring constant k acts on the mass m as a restoring force. In practice, the bowl 10 is coupled to the lower base block 11 by a plurality of inclined leaf springs 12 arranged at equal angular intervals, as shown in FIG. A fixed electromagnet 13 is fixed on the base block 11, and a coil 14 is wound around the fixed electromagnet 13. Further, an eddy current type sensor 16 is disposed in the vicinity of the upper end of the inclined leaf spring 12, and is supported on the base block 11 via a support column. The sensor 16 detects a vibration displacement x of the bowl 10.
[0004]
The output signal G of the displacement x detected by the sensor 16 is sent to the amplitude detector 5 and the self-excited oscillation controller 3 ′ via the DC cut filter (high-pass filter) 8 in the electric circuit 4 shown in FIG. Supplied. The amplitude detector 5 takes the absolute value Abs of the displacement x detected in a known manner, smooths this value with the low-pass filter 50, and determines the amplitude x ′ of the bowl 10 from the displacement x (this is the output of the displacement x). DC level corresponding to the signal). The amplitude detector 5 may be a half-wave rectification type or an rms circuit. The amplitude x 'is supplied as an output to the amplitude controller 6'. The amplitude controller 6 ′ calculates a deviation Δr between the amplitude x ′ and the amplitude command value xr that is the target amplitude value (however, both are calculated by changing them to effective values), and based on this deviation Δr. Variable gain K₀ And the variable amplifier 7 of the self-excited vibration controller 3 '₀ Adjust to take the value of. In the self-excited vibration controller 3 ′, the variable gain K is changed in the variable amplifier 7.₀ The signal of the fed back displacement x is amplified by the value of. Further, this is amplified by the power amplifier 9. In FIG. 11, the power amplifier 9 is shown with a saturation characteristic. This is because the output of the power amplifier 9 does not actually become infinite but has a finite value. . Then, the signal amplified by the power amplifier 9 is supplied to the coil 14 of the fixed electromagnet 13 to vibrate the bowl 10 of the vibration part feeder 2.
[0005]
Therefore, although the vibration parts feeder 2 of FIG. 10 is conceptually shown by a closed loop as shown in FIG. 11, the phase is delayed by 90 degrees between force and displacement at the resonance frequency in the transfer function of the bowl 10. Furthermore, since an electromagnet is used as the vibration drive source, the feedback gain is delayed by 90 degrees. Therefore, a phase difference of 180 degrees (π) occurs in the open loop, and the variable gain K₀ Is the actual stability limit gain K_crWhen larger than ', this vibration system oscillates and the amplitude grows. That is, when the detected amplitude is smaller than the amplitude command value, this variable gain K₀ The stability limit gain K_crGreater than 'and in steady state, variable gain K₀ The oscillation is oscillated and the amplitude is constant.
[0006]
[Problems to be solved by the invention]
    By the way, in Japanese Patent Application No. 7-97740, in order to improve the rising characteristics of self-excited vibration and to suppress the fluctuation of the variable gain due to the high frequency component (ripple) in the steady state, the variable gain K₀ Function to determineK
K = K₁ "・ Δr + K_Three "・ (Δr)^Three + K_cr"(K₁ "K_Three "Is a non-zero constant, K_cr"Is a stability limit gain). The coefficient of each term of this equation is conventionally defined as a constant (for example, a constant appropriate for the most commonly set amplitude command value). However, if this equation is applied to an amplitude command value other than the amplitude command value at the time of setting,₁ "K_Three Since “is a constant, the ratio to the amplitude command value changes greatly, and stable vibration cannot be performed.
[0007]
This will be specifically described with numerical values. For example, in the above formula, N = 1, K₁ "= K_Three "= 0.01, K_cr“= 0.1, ie variable gain K₀ Is gain K = 0.01 × Δr + 0.01 × Δr^Three Suppose that +0.1 is given. At this time, when the amplitude command value is 1, the deviation Δr between the amplitude command value and the detected amplitude value is substantially 1 at the start of self-excited vibration.₀ = 0.12, which is about 1/10 times the amplitude command value. When the amplitude command value is 10, the deviation Δr between the amplitude command value and the detected amplitude value is approximately 10 at the start of self-excited vibration.₀ = 10.2, which is about 1 time the amplitude command value. That is, if the amplitude command value is small, the rising characteristic is deteriorated.
[0008]
    By the way, variable gain K₀ Function to determineK, K = K₁ "・ Δr + K_Three "・ (Δr)^Three + K_cr"(K₁ "K_Three "Is a non-zero constant, K_cr"" Is a stability limit gain), the desired amplitude value may not be obtained in a steady state if the mass, damping rate, spring constant, etc. of the vibration system that becomes the load changes. In order to do this, the inventor has made a variable gain K₀ Function to determineK, K = K₁ "・ Δr + K_Three "・ (Δr)^Three + K_s "・ ∫Δrdt + K_cr(K₁ "K_Three "K_s "Is a non-zero constant, K_crIs an offset gain). Note that the variable gain K₀ FIG. 11 shows a simulation model that actually gives. In the model of FIG.₁ "K_Three "K_s The coefficient "" is set to an optimum value when the amplitude command value is 10, for example, K₁ "= 0.03, K_Three "= 1/35000, K_s "= 0.00010, K_crWhen = 0.00 is set, when the amplitude command value is 10, an amplitude waveform as shown in A of FIG. 12 is obtained. FIG. 12A also shows an enlarged view of a steady-state waveform after 1900 to 2000 seconds have elapsed from the start of vibration generation. Also, the amplitude waveform when the amplitude command value is 1 under this condition is shown in FIG. In addition, the enlarged view of the waveform when 1900-2000 sec passes since the vibration generation start at this time is also shown collectively. As apparent from A of FIG. 12, the rise time from 0% to 95% when the amplitude command value is 10 is about 70 sec. When the amplitude command value is 1, it is clear from A of FIG. In addition, the rise time from 0% to 95% is about 400 sec. That is, when the amplitude command value is reduced, the rise of vibration is delayed and the rise characteristic is deteriorated.
[0009]
By the way, in the amplitude detector 5 that obtains an amplitude value from the displacement x, the low-pass filter 50 removes the high-frequency component and smoothes it. In the amplitude detector 5, if the cutoff frequency is lowered in order to completely remove the high frequency component, the sine wave signal detected by the amplitude detector 5 is affected. For this reason, the amplitude detector 5 cannot completely remove the high-frequency component in order to reliably obtain the detected signal. Therefore, for example, a high frequency component twice the frequency of the sine wave signal detected by the amplitude detector remains. In steady state, variable gain K₀ Is the stability limit gain K_crThe frequency that cannot be removed is the stability limit gain K_cr'Is superimposed on the variable gain K₀ Will fluctuate. Variable gain K₀ Changes the command voltage waveform (which is detected by a voltage detector indicated by 20 'in FIG. 11) that gives an excitation force to the vibration mechanical system, and is not in the shape of a sine wave. The fact that the command voltage waveform is distorted means that many high-frequency components are included, and therefore drive noise occurs even in a steady state. In particular, when the amplitude is large, the frequency of the high frequency component that cannot be removed (for example, twice the frequency of the detected sine wave signal) becomes high. Therefore, proportional gain K that determines steady-state behavior₁ When the gain of “is constant, as the amplitude value increases, the high frequency component cannot be removed and remains, the waveform of the command voltage is greatly distorted, and a large drive noise is generated.
[0010]
Actually, it was obtained when the amplitude command value was set to 10 in the simulation model shown in FIG. 11 described above (conditions such as the mass of the vibration system, the damping rate, and the spring constant are as described above). The waveform of the command voltage (which is a sine wave) is shown in FIG. This is described in the same time width as the enlarged view of the amplitude of 1900 sec to 2000 sec shown in A of FIG. 12 (in a steady state), but the phase is shifted by 180 degrees (π). Further, the amplitude waveform obtained when the amplitude command value is 25 is shown in FIG. 14A (described in the same time width as the enlarged amplitude of 1900 sec to 2000 sec in the steady state). The waveform of the command voltage is shown in FIG. This is described in the same time width as the enlarged view of the amplitude of 1900 sec to 2000 sec (in a steady state) shown in FIG. 14A, but the phase is shifted by 180 degrees (π). A command voltage having an amplitude command value of 10 (shown in B of FIG. 12) has a substantially clean sine wave shape and has almost no distortion, but a command voltage having an amplitude command value of 25 (FIG. 14). (Shown in B) does not have the shape of a sine wave, and the waveform is distorted. That is, driving noise is generated in a steady state.
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and even when the amplitude command value, which is a desired amplitude value, is changed, a good rising characteristic is always obtained, the amplitude is not distorted in a steady state, driving noise is reduced, It is an object of the present invention to provide a self-excited vibration type vibration device capable of increasing the stability.
[0012]
[Means for Solving the Problems]
  The above problems include a vibration speed detecting means for detecting the vibration speed of the vibration device, an output of the vibration speed detecting means as a positive feedback signal, and the output of the vibration speed detecting means as a variable gain K.₀ A controller that amplifies the vibration device, a power amplifier that amplifies the output from the controller, a vibration drive source that vibrates the vibration device in response to the output of the power amplifier, and the vibration device from the output signal of the vibration speed detection means Amplitude detecting means for detecting the amplitude of the variable gain K and the variable gain K₀ The Function to be definedAn amplitude controller that outputs K in accordance with an amplitude deviation Δr between the amplitude detected from the amplitude detecting means and the amplitude command value, and the amplitude detected from the amplitude detecting means is between the amplitude command value and the amplitude command value. In the self-excited vibration type vibration device, the self-excited vibration is grown or attenuated when there is a deviation inAn expression representing the function K is:
K = K ₁ ・ Δr + K _{2N + 1} ・ (Δr) ^{2N + 1} + K _s ・ ∫Δrdt + K _cr Where the coefficient, K ₁ , K _{2N + 1} , K _s Is a variable that changes according to the magnitude of the amplitude command value.Yes, N is an integer, K _cr Is the offset gainThis is solved by a self-excited vibration type vibration device.
[0013]
With such a configuration, even if the desired amplitude value is freely changed, the rising characteristics are always good, and noise in a steady state can be reduced.
[0014]
  Further, the above-described problem is that vibration displacement detection means for detecting vibration displacement of the vibration device, output from the vibration displacement detection means is fed back as a negative feedback signal, and the output of the vibration displacement detection means is variable gain K.₀ A controller that amplifies in phase and controls phase delay with an integral element or first-order lag element, a power amplifier that amplifies the output from the controller, and a vibration drive source that receives the output of the power amplifier and vibrates the vibration device, Amplitude detecting means for detecting the amplitude of the vibration device from the output signal of the vibration displacement detecting means; and the variable gain K₀ Function to determineAn amplitude controller that outputs K in accordance with an amplitude deviation Δr between the amplitude detected from the amplitude detecting means and the amplitude command value, and the amplitude detected from the amplitude detecting means is between the amplitude command value and the amplitude command value. In a self-excited vibration type vibration device in which self-excited vibration is grown or damped when there is a deviation inThe expression representing the function K is:
K = K ₁ ・ Δr + K _{2N + 1} ・ (Δr) ^{2N + 1} + K _s ・ ∫Δrdt + K _cr Where the coefficient, K ₁ , K _{2N + 1} , K _s Is a variable that changes according to the magnitude of the amplitude command value, N is an integer, K_crIs an offset gain, which is solved by a self-excited vibration type vibration device.
[0015]
With such a configuration, even if the desired amplitude value is freely changed, the rising characteristics are always good, and noise in a steady state can be reduced. Further, since the vibration to be fed back is a displacement signal, the output from the displacement sensor can be used as it is, and the influence of noise can be reduced.
[0016]
  Further, the above-described problem is that vibration displacement detection means for detecting vibration displacement of the vibration device, output from the vibration displacement detection means is fed back as a negative feedback signal, and the output of the vibration displacement detection means is variable gain K.₀ A power amplifier for amplifying the output from the controller, an electromagnet for generating a magnetic attraction force for vibrating the vibration device in response to the output of the power amplifier, and a vibration displacement detecting means Amplitude detecting means for detecting the amplitude of the vibration device from an output signal; and the variable gain K₀ Function to determineAn amplitude controller that outputs K in accordance with an amplitude deviation Δr between the amplitude detected from the amplitude detecting means and the amplitude command value, and the amplitude detected from the amplitude detecting means is between the amplitude command value and the amplitude command value. In the self-excited vibration type vibration device in which the self-excited vibration is grown or attenuated when there is a deviation inThe expression representing the function K is:
K = K ₁ ・ Δr + K _{2N + 1} ・ (Δr) ^{2N + 1} + K _s ・ ∫Δrdt + K _cr Where the coefficient, K ₁ , K _{2N + 1} , K _s Is a variable that changes according to the magnitude of the amplitude command value, N is an integer, K_crIs an offset gain, which is solved by a self-excited vibration type vibration device.
[0017]
With such a configuration, even if the desired amplitude value is freely changed, the rising characteristics are always good, and noise in a steady state can be reduced. In addition, since an electromagnet with a 90-degree delay is used as the vibration drive source, it is not necessary to include an element that causes a phase delay in the controller, and the configuration can be simplified.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
When the deviation Δr between the amplitude command value that is the target value and the detected amplitude value is large, a positive feedback speed signal (this is detected by the vibration speed detection means) or a negative feedback displacement signal (this is vibration) Variable gain K for amplifying (detected by the displacement detecting means)₀ In a self-excited vibration type vibration device in which self-excited vibration is generated and vibration is grown.₀ At least one of the coefficients in the equation for determining the gain K that gives the value is a variable that changes according to the magnitude of the amplitude command value. That is, since the coefficient is changed in accordance with the magnitude of the set amplitude command value, even if the magnitude of the amplitude command value is freely changed, a good rise characteristic is always obtained, and In a steady state, the command voltage is not distorted and has a clean sine wave shape, so that driving noise can be reduced and stable driving can be achieved.
[0019]
Furthermore, variable gain K₀ The formula for determining the gain K that gives₁ ・ Δr + K_{2N + 1}・ (Δr)^{2N + 1}+ K_s ・ ∫Δrdt + K_cr(However, K₁ , K_{2N + 1}, K_s Is the coefficient, N is an integer, K_cr(Offset gain) is not only good in start-up characteristics, but even if the mechanical system mass, damping rate, spring constant, etc. of the load changes, the amplitude that the vibration device actually drives in steady state The desired amplitude command value can always be obtained.
[0020]
Variable gain K₀ The formula for determining the gain K that gives₁ ・ Δr + K_{2N + 1}・ (Δr)^{2N + 1}+ K_s ・ ∫Δrdt + K_cr(However, K₁ , K_{2N + 1}, K_s Is the coefficient, N is an integer, K_crIs the offset gain), the coefficient K in this equation₁ Is inversely proportional to the amplitude command value and the coefficient K_{2N + 1}Is set to be inversely proportional to the 2N + 1 power of the amplitude command value. At this time, for example, if a constant corresponding to the amplitude command value that performs the optimum behavior is given, the ratio of these constants to the amplitude command value is the same for any amplitude command value. Vibrations can be grown with good rise characteristics, and steady-state drive noise can be reduced.
[0021]
Furthermore, when the characteristics of the vibration device do not vary greatly from a certain reference state, the stability limit gain of the reference state is set to the variable gain K₀ K = K, which is an expression for determining the gain K that gives₁ ・ Δr + K_{2N + 1}・ (Δr)^{2N + 1}+ K_s ・ ∫Δrdt + K_cr(However, K₁ , K_{2N + 1}, K_s Is the coefficient, N is an integer, K_crIs the offset gain K)_crIt is good to do. In this way, the mass, damping rate, spring constant, etc. of the vibration system changes, and when compensating for the deviation, the compensation amount (by the integral element that is a delay element) can be reduced, so it is more real time. Can be controlled.
[0022]
If the amplitude detector cannot remove all the high-frequency components, the variable gain K₀ Fluctuates greatly and variable gain K₀ There is a case where the gain K for giving a negative value. For example, assume that the displacement of the vibration device detected in the steady state changes as shown in FIG. At this time, when the displacement of the vibration device is completely smoothed by the amplitude detector and all the high-frequency components can be removed, in a steady state, a constant value and a variable gain K indicated by a one-dot chain line in FIG.₀ Is the actual stability limit gain K_cr'Is output. However, as described above, it is difficult to remove all high-frequency components with the amplitude detector, and, for example, a frequency component twice the frequency of the sine wave signal detected by the vibration detector remains. At this time, the high frequency component that could not be removed is the actual stability limit gain K_cr'Is superposed on the variable gain K₀ The output of fluctuates. When the superposed high frequency component is large as shown by the solid line in FIG.₀ Is a negative value. If this is output as it is, the waveform of the command voltage for applying the excitation force to the vibration device is as shown by the solid line C in FIG. 6C shows a variable gain K.₀ Is a constant value (stable limit gain K_crThe waveform of the command voltage when it can be taken (ideally when all the high-frequency components are removed) is indicated by a one-dot chain line. In addition, the command voltage waveform shown in C of FIG. 6 is 180 degrees (π) out of phase with the waveform of the displacement shown in A of FIG. In the waveform of the command voltage indicated by the solid line in FIG. 6C, the output in the case of a negative value is a portion indicated by W, and the command voltage waveform includes a considerable amount of high frequency components. Therefore, the vibration device cannot be driven at the resonance frequency, and noise is also greatly generated. In addition, amplitude control becomes difficult. Therefore, when the gain K is a negative value, the variable gain K₀ Such a problem can be suppressed by providing a gain limiter that sets zero to zero. That is, at this time, when the gain K> 0, the variable gain K₀ = Gain K, but when gain K ≦ 0, variable gain K₀ = 0. Therefore, even when the amplitude command value is quite large, the driving noise in the steady state can be further reduced.
[0023]
Variable gain K₀ The formula for determining the gain K that gives₁ ・ Δr + K_{2N + 1}・ (Δr)^{2N + 1}+ K_s ・ ∫Δrdt + K_cr(However, K₁ , K_{2N + 1}, K_s Is the coefficient, N is an integer, K_crIs an offset gain), it is an integral element, so a variable gain K₀ The deviation between the target amplitude and the actual amplitude is accumulated in the integration element at the time of the rise of the gain K that gives a large amount of overshoot. Therefore, the coefficient K of the integral element_s For example, at the start of self-excited vibration, the coefficient K_s It is good to change it with the passage of time, such as making it very small and gradually increasing it with the passage of time. Note that, at this time, the coefficient K of the integral element from the start time of self-excited vibration until the amplitude of the vibration device reaches a predetermined time_s Or zero until the amplitude of the vibration device reaches a predetermined time from the start time of self-excited vibration (that is, from the start time of self-excited vibration, the vibration device If the input gain to the integrator that constitutes ｒΔrdt is zero until the amplitude of Δrdt reaches a predetermined time), the overshoot can be further suppressed. Further, when the amplitude of the vibration device detected by the amplitude detection means reaches a predetermined ratio of the amplitude command value at the predetermined time, for example, when the detected amplitude reaches about 70% of the amplitude command value. If so, it is possible to always suppress overshoot even if the magnitude of the amplitude command value changes. Immediately after the amplitude starts, the coefficient K of the integral element_s Of the integral element as the amplitude grows, so that the value of_s The value of may be increased. In this case, the coefficient K of the integral element according to the passage of time in advance._s A table in which the value of the vibration element is determined may be used, or the coefficient value of the integral element may be changed every time the detected amplitude of the vibration device reaches a predetermined ratio of the amplitude command value. .
[0024]
【Example】
In the following, embodiments of the present invention will be described with reference to the drawings. The same parts as those in the conventional example are given the same reference numerals, and detailed description thereof will be omitted.
[0025]
FIG. 1 is a block diagram of a self-excited vibration type vibration device according to an embodiment of the present invention. In the drawing, the vibration machine 21 is not limited to a vibration parts feeder in this embodiment, but is a general vibration device. In this vibration machine 21, as in the vibration part feeder 2 of the conventional example, the mass m is the acceleration d.² x / dt² When the vibration factor is 1 / s (s is a Laplace transducer—the same applies hereinafter), the velocity is dx / dt, which is multiplied by the viscosity coefficient c, and the vibration damping force is applied to the mass m. Works. Further, when the speed dx / dt passes through the integral element 1 / s, the displacement x is obtained, and the product of this multiplied by the spring constant k acts on the mass m as a restoring force. The displacement x of the vibration machine 21 is detected by a vibration displacement detector 22 composed of a sensor, as in the conventional example. The output signal of the detected displacement x is supplied to the amplitude detector 5 and the self-excited oscillation controller 3. Similar to the conventional example, the amplitude detector 5 obtains the amplitude of the vibration machine 21 from the signal of the displacement x and supplies it to the amplitude controller 30 described later.
[0026]
On the other hand, the self-excited oscillation controller 3 has a variable gain K given by the amplitude controller 30.₀ In the variable amplifier 7, the variable gain K₀ The signal of the displacement x fed back is amplified with an amplification factor of. Note that noise n may be added to the signal of the displacement x supplied to the self-excited oscillation controller 3. Further, this is amplified by the power amplifier 9 and supplied to the vibration drive source 17 that applies the excitation force to the vibration machine 21. In this embodiment, the vibration drive source 17 is an electromagnet and has a phase delay of 90 degrees. Therefore, a phase delay of 180 degrees (π) occurs in the open loop, and the variable gain K₀ Is the actual stability limit gain K_crIf it is larger than ', self-excited vibration is generated and the vibration grows.
[0027]
Next, the amplitude controller 30 according to the present invention will be described with reference to FIG.
[0028]
An amplitude command value xr that is a desired amplitude value is input to the amplitude controller 30. Further, the amplitude value x ′ detected from the amplitude detector 5 is supplied to this. In the amplitude controller 30, the adder / subtractor 24 calculates the deviation Δr from the amplitude command value xr and the amplitude value x ', that is, the amplitude value x' is subtracted from the amplitude command value xr. The deviation Δr is supplied to the proportional value calculation unit 25, the third power value calculation unit 26 (N = 1 here), and the integral value calculation unit 27. In the proportional value calculation unit 25, the deviation Δr is converted into a coefficient K.₁ This coefficient K₁ Changes according to the value of the amplitude command value xr. In the cube value calculation unit 26, the multiplier 19 'multiplies the deviation Δr three times, that is, (Δr)^Three After calculating the coefficient K_Three In this embodiment, this coefficient K is also amplified._Three Changes according to the value of the amplitude command value xr. The integral value calculation unit 27 calculates the deviation Δr as a coefficient K._s In FIG. 2, this coefficient K is passed through the integration element 1 / s._s Also depends on the magnitude of the amplitude command value xr. Then, the adder 28 adds the calculation results of the proportional value calculation unit 25, the third power value calculation unit 26, and the integral value calculation unit 27. The value added by the adder 28 is supplied to the adder 28 ', where it is further set to a set stability limit gain K (for example, a stability limit gain that can be obtained in the reference state)._crAdd In this way, the amplitude controller 30 is K = K₁ ・ Δr + K_Three ・ (Δr)^Three + K_s ・ ∫Δrdt + K_crAnd gain K is obtained. In the present embodiment, a gain limiter 29 is provided between the amplitude controller 30 and the variable amplifier 7. The gain limiter 29 outputs a value as it is when the gain K obtained by the amplitude controller 30 has a positive value, and outputs a zero value when the gain K has a negative value. . That is, at this time, when the gain K> 0, the variable gain K₀ = Gain K, but when gain K ≦ 0, variable gain K₀ = 0.
[0029]
The embodiment of the present invention is configured as described above. Next, this operation will be described.
[0030]
Although not shown, a DC power source is connected to the power amplifier 9 of FIG. 1 via a switch, and when the vibration machine 21 is driven by self-oscillation, the switch is closed and the power amplifier 9 is put into an operating state. In addition, the self-excited oscillation controller 3, the amplitude controller 30, and the like are similarly put in an operating state. In the amplitude controller 30, the vibration is first oscillated by a minute signal such as the external noise n, and the amplitude deviation Δr becomes the maximum because the amplitude of the movable part of the vibration machine 21 is zero. Accordingly, the gain K is accordingly K = K₁ ・ Δr + K_Three ・ (Δr)^Three + K_s ・ ∫Δrdt + K_crSince the value at this time is a positive value, the variable gain K₀ Becomes a gain K. Therefore, the variable gain K₀ Is the actual stability limit gain K_crWhen larger than ', self-excited vibration is generated and the vibration grows. In this embodiment, since the odd function is used, the rising characteristic is good. In FIG. 1, the coefficient K₁ , K_Three , K_s Is changed according to the amplitude command value, so that the rising characteristic does not change due to the change of the amplitude command value, and the steady-state noise can be removed.
[0031]
FIG. 3 shows a block diagram of an actually simulated model. In the actual model, the mass m of the vibration machine 21 is set to 1, the damping rate c = 0.001, and the spring constant k = 1. In the block diagram of FIG. 3, the amplitude command value xr supplied to the adder / subtractor 24 is actually the effective value of the amplitude command value xr (the value when the amplitude is DC, that is, the amplitude command value xr is 1). ..., That is, the adder / subtractor 24 compares the detected effective value of the amplitude with the effective value of the amplitude command value. In the figure, F₁ The input value is u₁ And output y₁ Then y₁ = (10 / 1.41) / u₁ Is an arithmetic unit that calculates F₂ The input value is u₂ And the output is y₂ And y₂ = (10 / 1.41)^Three / U₂ Is an arithmetic unit for calculating. F₂ Is supplied with a value obtained by squaring the amplitude command value xr. Therefore, the coefficient K of the proportional value calculation unit 25 '₁ Is K₁ = K₁ ’・ Y₁ = 0.003 × {(10 / 1.41) / xr} (where K₁ 'Is a coefficient), and the coefficient K of the cube value calculation unit 26_Three Is K_Three = K_Three ’・ Y₂ = {(10 / 1.41)^Three / (Xr)^Three } / 35000 (however, K_Three 'Is a coefficient). The coefficient K₁ ′ And coefficient K_Three When the amplitude command value is 10, the command voltage waveform is a clean sine wave in a steady state, that is, a constant with low driving noise and good rising characteristics. In the block diagram shown in FIG. 3, the coefficient K of the integral value calculation unit 27_s Is a constant, K_s = 0.00010. In FIG. 3, the offset gain K_crIs set to 0.00.
[0032]
Further, when the amplitude command value xr is set to an effective value of 10, the block diagram in FIG. 3 is exactly the same as the block diagram in FIG. 12 of the conventional example, and the obtained amplitude waveform and command voltage waveform are the same as in FIG. Exactly the same waveform, that is, a clean sine wave. Therefore, at this time, a good rise characteristic is obtained, and the waveform is not distorted even in a steady state and a clean sine wave is obtained, so that driving noise can be reduced.
[0033]
FIG. 4A shows an amplitude waveform when the amplitude command value xr is 25. An enlarged view of the amplitude waveform of 1900 sec to 2000 sec, which is a steady state at this time, is also shown in FIG. 4A. Further, the amplitude command value xr is set to 25, and the time width in the enlarged view of FIG. 4A, that is, the temporal change of the command voltage waveform in 1900 sec to 2000 sec is shown in FIG. 4B. As apparent from FIG. 4B, in the present invention, even when the amplitude command value is 25, the amplitude waveform has a clean sine wave shape, and the command voltage is hardly distorted.
[0034]
Furthermore, an amplitude waveform when the amplitude command value xr is set to 1 is shown in FIG. An enlarged view of the amplitude waveform of 1900 sec to 2000 sec, which is a steady state at this time, is also shown in FIG. 5A. Further, the amplitude command value xr is set to 1, and the time width in the enlarged view of FIG. 5A, that is, the temporal change of the command voltage waveform in 1900 sec to 2000 sec is shown in FIG. 5B. As apparent from FIG. 5A, even when the amplitude command value is as small as 1, the rise time from 0% to 95% is about 70 sec, and the rise characteristic is the rise when the amplitude command value xr is 10. It is almost the same as the characteristics and is good.
[0035]
In FIG. 4 or FIG. 5, an excessive overshoot occurs. For example, in FIG. 5, the amplitude command value xr is 25, but an overshoot of about 50, which is almost twice as large, is generated. This is a variable gain K₀ The formula that determines the gain K that gives_s This is because it has ∫Δrdt). Therefore, in order to prevent this excessive overshoot, the coefficient K of the integral value calculation unit 27 is_s Alternatively, the input gain to the integrator constituting ∫Δrdt may change with time. For example, the integral term 27 may be turned off until the amplitude value reaches about 70% of the amplitude command value, and the integral term may be added after the amplitude value becomes 70% or more of the amplitude command value.
[0036]
As mentioned above, although the Example of this invention was described, of course, this invention is not limited to this, A various deformation | transformation is possible based on the technical idea of this invention.
[0037]
For example, in the above embodiment, the vibration displacement of the vibration machine 21 is detected, the detection signal is negatively fed back to the self-excited oscillation controller 3, and a phase delay of 90 degrees is generated between the voltage and the excitation force as a vibration drive source. An electromagnet was used. However, when there is no phase lag between the voltage and the excitation force as the vibration drive source, as shown in FIG. 7, for example, when the vibration drive source 17 ′ such as an electrodynamic type or a piezoelectric type is used, 90 If a self-excited oscillation controller 3 ″ having a phase controller 41 that generates a phase delay of degree (π / 2) (shown by a first-order lag element in FIG. 7 but may be an integral element) is used, The present invention is applicable, for example, as a self-excited vibration type vibration device using the vibration drive source 17 ′ having no phase delay, there is a vibration part feeder 2 ′ shown in FIG. The bowl 10 ′, which is a movable part, is coupled to the base block 11 ′ by a plurality of inclined leaf springs 12 ′ disposed at equal angular intervals.The base block 11 ′ is supported on the floor by a vibration isolating rubber 43. The A known drive mass body 44 is disposed between the bowl 10 ′ and the base block 11 ′, and is coupled to the base block 11 ′ by a leaf spring 45 disposed substantially horizontally and at equal angular intervals. Piezoelectric elements 46a and 46b are attached to both surfaces of each leaf spring 15, and an AC voltage (not shown) is applied to the piezoelectric elements 46a and 46b. Then, bending vibration is generated in the leaf spring 15 and the vibration parts feeder is vibrated. In the self-excited oscillation controller 3 ″ shown in FIG. 7, the phase controller 41 is provided in front of the variable amplifier 7. It may be provided after. Further, in the above embodiment, the full-wave rectification type detector, that is, the absolute value conversion and the low-pass filter is used as the amplitude detector. However, by this other method, for example, a half-wave rectification type detector or A detector using an rms circuit may be used.
[0038]
In the above embodiment, the coefficient K₁ , K_Three Is made variable as a function related to the amplitude command value, but a correspondence table between the amplitude command value and the coefficient may be created, and the coefficient may be changed according to this table.
[0039]
Further, as shown in FIG. 9, the vibration speed detector 42 detects the vibration speed of the vibration machine 21 and positively feeds back this to obtain an amplitude from the vibration speed (for example, having an integrator). Gain K given by the amplitude controller 30 receiving₀ The self-excited vibration may be generated by amplification.
[0040]
In the above embodiment, when the gain K is a positive value, the value is output, and when the gain K is a negative value, the variable gain K is output.₀ A gain limiter 29 is set to zero. However, any gain limiter may be used as long as the gain K output from the amplitude controller 30 becomes zero when the gain K is a negative value. For example, the gain K is an actual stability limit gain K._crThe gain K may be set to zero when the value is less than a positive value sufficiently smaller than ', and the gain K may be output as it is when larger than the positive value. Further, the amplitude detector 5 can substantially remove high-frequency components, and the steady state (variable gain K₀ This gain limiter need not be provided when the variation in gain K is small and always becomes a positive value.
[0041]
In the above embodiment, the variable gain K₀ Gain K giving K = K₁ ・ Δr + K_Three ・ (Δr)^Three + K_s ・ ∫Δrdt + K_cr(However, K₁ , K_Three , K_s Is the coefficient, N is an integer, K_crIs offset gain), but K_Three ・ (Δr)^Three Instead of K_Five ・ (Δr)^Five , K₇ ・ (Δr)⁷ ... K_{2N + 1}・ (Δr)^{2N + 1}Even if an odd function is used, the rise characteristic can be improved.
[0042]
【The invention's effect】
As described above, according to the self-excited vibration type vibration device of the present invention, even if the amplitude command value is arbitrarily changed, the rising characteristics can be always improved. In addition, even if the amplitude command value is arbitrarily changed, the command voltage waveform in the steady state is hardly distorted and a clean sine wave can be obtained, so that vibration drive sound can be reduced and amplitude stability can be increased. Can do.
[Brief description of the drawings]
FIG. 1 is a block diagram of a self-excited vibration type vibration device according to an embodiment of the present invention.
FIG. 2 is a block diagram showing details of an amplitude controller used in a self-excited vibration type vibration device according to an embodiment of the present invention.
FIG. 3 is a block diagram of a model in which simulation is performed according to an embodiment of the present invention.
4 is a time chart showing a temporal change of a waveform when an amplitude command value is 25 in the block diagram shown in FIG. 3, A is a time change of an amplitude value, and B is a command voltage for driving an electromagnet. The time change of a waveform is shown.
5 is a time chart showing a temporal change of a waveform when an amplitude command value is 1 in the block diagram shown in FIG. 3. A shows a time change of an amplitude value, and B is a command voltage for driving an electromagnet. The time change of a waveform is shown.
FIGS. 6A and 6B are diagrams illustrating waveforms for explaining the operation of the gain limiter used in the embodiment of the present invention, in which A represents a signal waveform of the displacement x fed back, and B represents a variable gain K in a steady state.₀ C represents the waveform of the command voltage applied to the vibration drive source.
FIG. 7 is a block diagram of a self-excited vibration type vibration device according to a first modification of the present invention.
FIG. 8 is a perspective view of a vibrating parts feeder to which a first modification of the present invention is applied.
FIG. 9 is a block diagram of a self-excited vibration type vibration device according to a second modification of the present invention.
FIG. 10 is a block diagram of a self-excited vibration type vibration device according to a conventional example.
FIG. 11 is a block diagram of a model for which a simulation according to a conventional example is performed.
12 is a time chart showing a temporal change of a waveform when an amplitude command value is 10 in the block diagram shown in FIG. 11, A showing a temporal change of an amplitude value, and B being a command voltage for driving an electromagnet; The time change of a waveform is shown.
13 is a time chart showing a temporal change of a waveform when an amplitude command value is 25 in the block diagram shown in FIG. 11, A showing a temporal change of an amplitude value, and B being a command voltage for driving an electromagnet; The time change of a waveform is shown.
14 is a time chart showing a temporal change of a waveform when the amplitude command value is 1 in the block diagram shown in FIG. 11. A shows a time change of the amplitude value, and B is a command voltage for driving the electromagnet. The time change of a waveform is shown.
[Explanation of symbols]
3 Self-excited oscillation controller
3 ”self-oscillation controller
5 Amplitude detector
7 Variable amplifier
9 Power amplifier
17 Vibration drive source
17 'vibration drive source
21 Vibration machine
22 Vibration displacement detector
24 Adder / Subtractor
25 Proportional value calculator
26 cubed value calculation unit
27 Integral value calculator
28 Adder
28 'adder
28 "adder
29 Gain limiter
30 Amplitude controller
41 Phase controller
42 Vibration speed detector
K gain
K₀     Variable gain
K₁     coefficient
K_Three     coefficient
K_cr    Stability limit gain
K_s     coefficient
x displacement
x '(actual) amplitude value
xr Amplitude command value
Δr deviation

Claims (9)

Vibration speed detection means for detecting the vibration speed of the vibration device, a controller that feeds back the output of the vibration speed detection means as a positive feedback signal, and amplifies the output of the vibration speed detection means with a variable gain K ₀ , and the controller A power amplifier that amplifies the output from the power, a vibration drive source that vibrates the vibration device in response to the output of the power amplifier, and an amplitude detection means that detects the amplitude of the vibration device from the output signal of the vibration speed detection means When, the variable gain K ₀ An amplitude controller that outputs a function K to be determined in accordance with an amplitude deviation Δr between the amplitude detected from the amplitude detection means and the amplitude command value, and the amplitude detected from the amplitude detection means is the amplitude command value In the self-excited vibration type vibration device in which the self-excited vibration is grown or attenuated when there is a deviation between the expressions,
K = K ₁ ・ Δr + K _{2N + 1} ・ (Δr) ^{2N + 1} + K _s ∫Δrdt + K _cr and coefficient, K ₁ , K _{2N + 1} , K _s is a variable that varies depending on the magnitude of the amplitude command value , N is an integer, and K _cr is an offset gain. . A vibration displacement detecting means for detecting a vibration displacement of the vibration device; an output from the vibration displacement detecting means is fed back as a negative feedback signal; the output of the vibration displacement detecting means is amplified by a variable gain K ₀ ; A controller that performs phase delay control using a primary delay element, a power amplifier that amplifies the output from the controller, a vibration drive source that receives the output of the power amplifier and vibrates the vibration device, and an output of the vibration displacement detection means Amplitude detecting means for detecting the amplitude of the vibration device from the signal, and an amplitude for outputting the function K for determining the variable gain K ₀ according to the amplitude deviation Δr between the amplitude detected from the amplitude detecting means and the amplitude command value And a self-excited vibration is grown or attenuated when the amplitude detected from the amplitude detecting means has a deviation from the amplitude command value. Expression in self-excited oscillation type oscillation apparatus lend representing the function K: is
K = K ₁ ・ Δr + K _{2N + 1} ・ (Δr) ^{2N + 1} + K _s ∫Δrdt + K _cr and coefficient, K ₁ , K _{2N + 1} , K _s is a variable that changes in accordance with the magnitude of the amplitude command value , N is an integer, and K _cr is an offset gain. Vibration device. Vibration displacement detection means for detecting vibration displacement of the vibration device, a controller that feeds back an output from the vibration displacement detection means as a negative feedback signal, and amplifies the output of the vibration displacement detection means with a variable gain K ₀ , A power amplifier for amplifying the output from the controller; an electromagnet for generating a magnetic attraction force for vibrating the vibration device in response to the output of the power amplifier; and an output signal from the vibration displacement detection means. Amplitude detecting means for detecting an amplitude, and an amplitude controller for outputting a function K for determining the variable gain K ₀ according to an amplitude deviation Δr between the amplitude detected from the amplitude detecting means and an amplitude command value, Self-excited vibration type vibration in which self-excited vibration is grown or attenuated when the amplitude detected from the amplitude detecting means has a deviation from the amplitude command value. In the device, the formula representing the function K: is
K = K ₁ ・ Δr + K _{2N + 1} ・ (Δr) ^{2N + 1} + K _s ∫Δrdt + K _cr and coefficient, K ₁ , K _{2N + 1} , K _s is a variable that changes according to the magnitude of the amplitude command value , N is an integer, and K _cr is an offset gain. apparatus. 4. The self-excited vibration type vibration device according to claim _1, wherein the coefficient K ₁ is inversely proportional to the amplitude command value, and the coefficient K _{2N + 1} is inversely proportional to the (2N + 1) th power of the amplitude command value. 5. The self-excited vibration type vibration device according to any one of claims 1 to 4, wherein the offset gain K _cr is a stability limit gain in a reference state. Wherein when the gain K is negative value, self-excited oscillation type oscillation device according to any one of claims 1 to 5 comprising a gain limiter to a variable gain K ₀ zero. The self-excited vibration type vibration device according to any one of claims 4 to 6, wherein an input gain to the integrator constituting the coefficient K _s or the ∫Δrdt changes with the passage of time. 8. The input gain to the integrator constituting the coefficient K _s or the ΔΔrdt is zero from the start time of self-excited vibration until the amplitude of the vibration machine reaches a predetermined time. Self-excited vibration type vibration device.   The self-excited vibration type vibration device according to claim 8, wherein the predetermined time is when the amplitude of the vibration machine detected by the vibration detection unit reaches a predetermined ratio of the amplitude command value.

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