JPH09184536A - Vibration damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve vibration damping characteristics by calculating physical parameters of a mechanical spring for supporting a vibration resistant body and a viscous element on the basis of a calculating means for the simple physical parameter in which arbitrariness is eliminated and setting a compensating parameter of a floor vibration feedforward compensator on the basis of the calculated value. SOLUTION: While a signal is output from an oscillator 14, an electronic switch 16a for interrupting a signal of a feedback device 12, and a switch 16b for interrupting a signal of a feedforward device 23 are opened by a control signal 15. A vibration compensating stand 1 is vibrated by exciting a power amplifier 7 by the output of the oscillator 14, the outputs of a pre-filter 5 and the oscillator 14 in the exiting period are guided to a physical parameter calculating means 17, and a compensating parameter of a floor vibration feedforward compensator 11 is set by a compensating parameter setting means 18 on the basis of the calculated value. After setting, damping is applied by the operation of the feedback device 12, simultaneously, the feedforward device 23 functions, and the vibration resistant ratio can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for suppressing the propagation of floor vibration to a vibration isolation table. Particularly, it is a vibration isolator suitably used as one component unit of a semiconductor exposure apparatus having an XY stage for exposure, and a vibration isolator or VCM using a voice coil motor (hereinafter abbreviated as VCM) as an actuator. The present invention relates to improvement of floor vibration damping rate of a vibration control device using other actuators in combination.

[0002]

2. Description of the Related Art On a vibration isolation table, a group of equipment that dislikes vibration is mounted. For example, it is an optical microscope or an XY stage for exposure. In particular, in the case of the exposure XY stage, the stage must be mounted on a vibration isolation table that eliminates vibrations transmitted from the outside as much as possible so that proper and quick exposure can be performed. This is because the exposure must be performed with the exposure XY stage completely stopped. In addition, XY for exposure
It should be noted that the stage has an intermittent motion called step & repeat as an operation mode, and the step vibration itself is repeatedly generated, which causes the vibration of the vibration isolation table. It is impossible to start the exposure operation even when such vibrations remain without being settled. Therefore, the anti-vibration table is required to achieve a good balance of anti-vibration against external vibration and damping performance of forced vibration caused by the movement of the mounted device itself.

Incidentally, instead of the step & repeat type semiconductor exposure apparatus in which the XY stage is completely stopped and then the exposure light is applied to the silicon wafer mounted on the stage, exposure is performed while scanning the XY stage and the like. A scan type semiconductor exposure apparatus that irradiates a silicon wafer with light has also appeared. Even for a vibration isolation table used in such a device, it is possible to satisfy a well-balanced balance between the external vibration isolation and the vibration isolation performance against the forced vibration caused by the movement of the equipment itself mounted on the vibration isolation table. The requirements are the same.

As is well known, the vibration isolator is classified into a passive vibration isolator and an active vibration isolator. High-accuracy positioning, high-accuracy scanning required for equipment mounted on the vibration isolation table,
In recent years, there is a tendency to use an active anti-vibration device in order to meet the demand for high-speed movement, and air springs, VCMs, piezoelectric elements, etc. are known as actuators used therein.

First, the structure and operation of a vibration isolation device using a VCM as an actuator will be described with reference to FIG. In the figure, 1 is a vibration isolation table, 2 is a first acceleration sensor for measuring the vibration of the vibration isolation table 1, 3 is a preload mechanical spring, 4 is a
Is a viscous element expressing the viscosity of the entire mechanism. Vibration isolation table 1
The output of the first acceleration sensor 2 for detecting the vibration is passed through the prefilter 5 to be appropriately filtered and converted into an electric signal. Then, the output signal of the pre-filter 5 passes through the integral compensator 6 and becomes a signal having the dimension of velocity, which excites the power amplifier 7, and as a result, the VCM 8 drives the vibration isolation table 1. This closed loop is called the feedback device 12. The floor vibration feedforward for removing or reducing the influence of the floor vibration on the vibration isolation table 1 is suitable through the filter 10 which detects the floor vibration by the second acceleration sensor 9 and filters its output and converts it into an electric signal. It is realized by adding to the front stage of the power amplifier 7 via the floor vibration feedforward compensator 11 having a different transfer function. This loop is called a feedforward device 23. VCM here
An example of the structure of No. 8 is shown in FIG. In the figure, 19 is a permanent magnet, 20 is a winding coil, 21 is a support frame for the winding coil 20, and 22 is a fixed frame for fixing the permanent magnet 19. When the support frame 21 is firmly fixed and a current is applied to the winding coil 20, a fixed frame 22 including the permanent magnet 19 is wound when the fixing frame 22 is firmly fixed and a current is applied to the winding coil 20. The supporting frame 21 including the wire coil 20 obtains a driving force.

As will be shown later, the basic structure of the transfer function of the floor vibration feedforward compensator 11 can be theoretically derived, and in order to realize the transfer function, physical parameters as a dynamic system of the vibration isolation table are required. Specifically, it is a spring constant and a viscous friction coefficient. As a method of calculating physical parameters,
In the field, a method using a gain curve of frequency response is often used. A conventional physical parameter calculation method based on a gain curve will be described below. Consider calculation of the spring constant K and the viscous friction coefficient C of the VCM type supporting leg 13 within the broken line with reference to FIG. The transfer function from the driving force f _d to the acceleration α of the vibration isolation table is given by equation (1).

[0007]

[Equation 2] The gain curve of this frequency response is as shown in FIG. Here, K and C can be calculated by reading the resonance magnification M _P and the frequency f _P that gives it, and sequentially performing the calculations from equations (2) to (5). However, the mass M is known.

[0008]

(Equation 3) Now, the actually measured gain curve of the frequency characteristic includes the gain of the power amplifier that generates f _d , the gain when the acceleration α is detected as the amount of electricity, and the like. Therefore, M
_P is the difference between the gain flat part in the high frequency range and the gain at the main resonance point f _P. However, in general, when measuring the frequency response from the driving force to the acceleration of the vibration isolation table in a structure such as the VCM type supporting leg 13 shown in FIG. 3, in many cases, in addition to the main resonance mode, several sub-resonance modes exist. However, it distorts a flat gain curve in the high frequency range.
Here, there is a factor that deteriorates accuracy in the physical parameter calculation. That is, the presence of the sub-resonant mode distorts the gain flat portion of the frequency characteristic, and the level determination becomes arbitrary. If M _P 's decision is arbitrary,
With reference to the expressions (2) to (5), K and C have ambiguous values. Here, FIG. 5 shows an inertance response, that is, one measured example of the equation (1). The ↑ mark in the figure is the main resonance point. Resonance also exists on the high frequency side of this point, thus disturbing the flatness of the gain curve at this portion.

Now, as a publicly known document concerning a floor vibration feed forward provided to reduce or eliminate the influence of the floor vibration on the vibration isolation table, Japanese Patent Application Laid-Open No. 6-23543.
No. 9 (“Vibration control method and device”). Here, a method for forming a feedforward signal by inputting floor vibration as a reference signal and vibration of a vibration isolation table as an error signal to an adaptive filter, and updating the filter coefficient based on an adaptive algorithm to process the reference signal and its A device configuration is disclosed. Further, Japanese Patent Laid-Open No. 7-93037 discloses an adaptive algorithm based on the least squares method, which obtains an error signal from the vibration state of a vibration isolation table.

These known materials are designed on the assumption that the transfer characteristics from the floor vibration to the vibration isolation table cannot be accurately grasped. The origin of the idea is to capture the ambiguous transfer characteristics from the floor to the vibration isolation table by using an adaptive algorithm. In summary, there are two methods of constructing a floor vibration feedforward compensator by an adaptive algorithm. Its characteristics are as follows.

(1) In case of recursive compensator Advantages: A low-dimensional compensator can be realized. Convergence is fast. Cons: Stability of compensator is not guaranteed.

(2) Non-recursive compensator Advantages: Stability is guaranteed. Cons: Higher order compensator and hence slow convergence.

The state of the floor on which the vibration isolation table is installed varies widely. The automatic generation of an appropriate floor vibration feedforward compensator that can deal with all kinds of floor vibration conditions is originally expected for the adaptive algorithm. However, in reality, due to the characteristics of the adaptive algorithm itself as described above, it is difficult to say that it is practical. There remains a problem that it is very difficult to realize a floor vibration feedforward that is stable under all kinds of floor vibration conditions and vibration conditions of the vibration isolation table and does not impair vibration isolation performance.

[0014]

The floor vibration feedforward is a signal obtained by detecting a floor vibration having a vibration isolation table by using a vibration sensor such as an acceleration sensor and performing appropriate compensation on the detected signal. Is forwarded to the actuator that drives the vibration isolation table, and as a result, the vibration that the floor vibration transmits to the vibration isolation table is suppressed. Here, the structure of the transfer function of a so-called floor vibration feedforward compensator for performing appropriate compensation can be theoretically calculated. However, the problem was that the calculated values of the physical parameters had to be used in the implementation.

In general, when the stability is ensured in the control system and further higher performance is desired, feedforward is used. The so-called control system structure has two degrees of freedom. The compensation parameter for feedforward is configured by using the physical parameter to be controlled, and the calculation accuracy thereof determines the performance of feedforward.

Such a situation is exactly the same in the vibration isolator provided with the floor vibration feedforward compensator, and how the physical parameters of the vibration isolation table to be controlled are accurately calculated and the values are calculated. Whether it can be reflected in the design of the vibration feedforward compensator directly affects the device performance. It is natural that the floor vibration feedforward compensator designed using inaccurate physical parameters cannot meet the specifications of the vibration damping ratio from the floor vibration to the vibration isolation table.

According to the present invention, the physical parameters are calculated more accurately than before, and the compensation parameters of the floor vibration feedforward compensator are set based on the calculated values to improve the vibration isolation characteristics of the vibration isolation device. To do.

[0018]

In order to solve the above-mentioned problems, a vibration isolator according to the present invention is a mechanical spring for supporting a vibration isolation table based on a calculation procedure of a physical parameter which is simple and free of arbitraryness. And the physical parameters of the viscous element are calculated, based on this value, the compensation parameters of the floor vibration feedforward compensator are set, and the feedforward loop including them is made to function.

More specifically, in the vibration isolator of the present invention, a voice coil motor for driving the vibration isolation table, a first acceleration sensor for detecting vibration of the vibration isolation table, and an output of the first acceleration sensor as an electric signal. For driving the vibration isolation table in response to an output signal of the pre-filter, an integral compensator for integrating the output of the pre-filter, and an integral compensator. A feedback device having a power amplifier that excites a voice coil motor, a second acceleration sensor that detects a floor vibration when a vibration isolation table is installed, and an output of the second acceleration sensor are converted into an electric signal and appropriate filtering processing is performed. A floor vibration feed filter having a filter for performing and an appropriate transfer function for compensating the output signal of the filter and feeding forward to the front stage of the power amplifier. In a vibration isolation device including a feedforward device having a word compensator, an electronic switch for connecting and disconnecting a signal in the feedback device and the feedforward device, and an oscillator for exciting a power amplifier to drive a vibration isolation table. , A physical parameter calculating means for calculating the dynamic physical parameters of the vibration isolation table by taking in the output signal of the oscillator and the output signal of the prefilter, and the floor vibration feedforward compensator based on the output of the physical parameter calculating means. Compensation parameter setting means for setting a compensation parameter is provided. In this case, the transfer function of the floor vibration feedforward compensator is PI
It is characterized by a transfer function in which a compensator and an integrator are cascade-connected or a transfer function of a double integrator.

Further, the output of the floor vibration feedforward compensator in the feedforward device may be a vibration isolator that feedforwards to the stage before the integral compensator in the feedback device. In this case, the floor vibration feedforward compensator becomes a transfer function of the PI compensator or the integral compensator whose order is decreased by one compared with the above-mentioned configuration.

[0021]

In calculating the physical parameters of the dynamic system, the real part curve in the frequency response is used instead of the conventional gain curve. The real part curve of the frequency response has better discrimination of the resonance mode than the gain curve, and the physical parameters calculated using the obtained data have high accuracy. Typically,
The feedforward compensation is used to realize the compensator for the parameter to be controlled, but the better the accuracy of the parameter that can be obtained, the better the effect of the feedforward compensation. Therefore, when the floor vibration feedforward compensator realized by using the physical parameters of the vibration isolation table with high accuracy is installed in the feedforward loop, it is possible to effectively suppress the propagation of floor vibration to the vibration isolation table. To work.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows the structure of a vibration isolation device using a VCM as an actuator according to an embodiment of the present invention. In the figure, the same or corresponding portions as those in FIG. 3 are designated by the same reference numerals, and detailed description thereof will be omitted. Reference numeral 9 is a second acceleration sensor for detecting floor vibration, and 10 is a filter for converting the output of the second acceleration sensor 9 into an electric signal to remove offset and high frequency noise. Reference numeral 11 is a floor vibration feedforward compensator, and this output signal is added to the preceding stage of the power amplifier 7. Reference numeral 14 is an oscillator, the output of which is applied to the front stage of the power amplifier 7. Electronic switch 1 for interrupting the signal of the feedback device 12 by the control signal 15 while the oscillator 14 is outputting the signal.
6a and the signal of the feedforward device 23 are intermittently connected 1
Both 6b are open. The power amplifier 7 is excited by the output of the oscillator 14 to excite the vibration isolation table 1, and the output of the prefilter 5 and the output of the oscillator 14 during the excitation period are guided to the physical parameter calculation means 17, which will be described later. The physical parameters are obtained according to the procedure. Based on the calculated value,
The compensation parameter setting means 18 sets the compensation parameter of the floor vibration feedforward compensator 11. After setting the parameters, the electronic switch 1 is controlled by the control signal 15.
6a and 16b are closed and damping is provided by the action of the feedback device 12, and at the same time, the feedforward device 23 also functions to improve the vibration isolation rate.

The background showing the effect of the floor vibration feedforward compensation in the above-mentioned device configuration will be described. Figure 7 is V
It is a block diagram of a vibration isolator using CM as an actuator. Using the symbols shown in the figure, variables x and f
The function of _dis and x ₀ is as shown in equation (6).

[0024]

(Equation 4) Here, in order to eliminate or reduce the influence of x ₀ on x, G _ff (s) is selected as in equation (8a) or (8b), that is, the PI compensator and the integrator are cascaded. The transfer function is a connected transfer function or a transfer function of a double integrator, where P means proportional and I means integral operation.

[0025]

(Equation 5) Although the background of another embodiment described later will be described in advance, the output of the floor vibration feedforward compensator 11 can be feedforward to the stage before the integral compensator 6 with reference to FIG. 9. In this case, the variables x, f _dis , x ₀
The relationship is as shown in equation (9).

[0026]

(Equation 6) To eliminate or reduce the effect of x ₀ on x,
G _ff (s) is selected as in equation (10a) or (10b). That is, G _ff (s) may be used as the transfer function of the PI compensator or the I compensator.

[0027]

(Equation 7) The symbols used have the following meanings.

X [m]: displacement of the vibration isolation table, f _dis [N]:
Disturbance, x ₀ [m]: displacement of floor vibration, M [kg]: mass,
C [N · sec / m]: Viscous friction coefficient, K [N / m]:
Spring constant, K _a [V / m / sec ² ]: Conversion gain from the output of the first acceleration sensor 2 to the electric quantity from the prefilter 5 (time constant is omitted for simplicity), k _ac [V / M
/ Sec ² ]: conversion gain from the output of the second acceleration sensor 9 to the electric quantity to the filter 10 (time constant is omitted for simplicity), B [1 / sec]: integral gain of the integral compensator 6, K _t [N / V]: V from the input to the power amplifier 7
Conversion gain up to thrust generated by CM8, G _ff (s)
[−]: Transfer function of the floor vibration feedforward compensator 11, s: Labrus operator.

As described above, when the actuator is the VCM, equations (8a) and (8b) or (10a) and (10
As shown in the equation (b), only the values of the spring constant K and the viscous friction coefficient C, or only the value of the spring constant K are necessary for realizing the floor vibration feedforward compensator G _ff (s).

Now, the physical parameter calculating means 17 of FIG.
Then, the following calculation is performed to calculate the physical parameters K and C. Here, f _max and f _min are frequencies giving peaks and bottoms in the real part curve of the frequency response shown in FIG.

[0031]

(Equation 8) The reason why the real part curve can better identify the main resonance mode of the dynamic system and the physical parameters thereof can be calculated more accurately than the gain curve of the frequency response can be explained as follows.

The fact that the main resonance mode is well recognized and the calculation accuracy of the physical parameters is high means that the curves change sharply when the parameters change, that is, the sensitivity is high. Let's compare the gain curve | G | of the equation (1) and the real part curve Re of the equation with the sensitivity function regarding the natural frequency f _n and the damping coefficient ζ and compare them. As is well known, the sensitivity function expresses the change of the characteristic value with respect to the parameter change of interest with a change rate. For example, if the characteristic value is Q and the parameter of interest is q (15)
Defined by an expression.

[0033]

[Equation 9] The calculation results are as follows. First, the sensitivity function for the frequency f is calculated, and when f = f _n is substituted, the gain curve |
The sensitivity of G | is shown in equation (16), and the sensitivity of the real part curve Re is shown in equation (17).

[0034]

(Equation 10) Comparing equations (16) and (17), the relation of equation (18) is easily established.

[0035]

[Equation 11] Similarly, when the sensitivity function regarding the damping coefficient ζ is calculated and compared, Expression (19) is obtained.

[0036]

(Equation 12) According to the equations (18) and (19), the sensitivity with respect to the natural frequency f _n and the damping coefficient ζ is higher in the real part curve than in the gain curve, and therefore the discriminability of the main resonance mode in the dynamic system is high. I can say.

As described above, in deriving the spring constant K and the viscous friction coefficient C, as can be seen from the equations (11) and (12), in the calculation of ζ and f _n as preprocessing, it is obtained from the real part curve of the frequency response. Use f _max and f _min . As shown in FIG. 5 of the actual measurement example, in the conventional case, the flat gain portion in the high frequency region is distorted due to the influence of the sub-resonance mode. The most arbitrary thing was to calculate the difference from the gain. However, even if the sub-resonance is present near the main resonance, it can be said that the distinction between the main resonance mode and the sub-resonance mode is good according to the equation (17), and there is no room for ambiguity.

[0038]

Other Embodiments Generally, in feedforward compensation, a feedforward signal is added to driving means for exciting an actuator. In the floor vibration feedforward compensation, which is the subject of the present invention, the output signal of the floor vibration feedforward compensator 11 is added before the power amplifier 7 as shown in FIGS. In this case, the obtained transfer function of the floor vibration feedforward compensator 11 is (8
As shown in equations (a) and (8b), both have two integrators. However, the problems of drift and saturation hinder the implementation. Although the theoretical background has already been described, in the case of FIG. 9, the transfer function of the floor vibration feedforward compensator 11 includes only one integrator as shown in the equations (10a) and (10b). Therefore, there is an advantage that the mounting problem is alleviated as compared with FIG. 7.

Therefore, the structure of the vibration isolator according to another embodiment of the present invention is shown in FIG. The difference from FIG. 1 is that the output of the floor vibration feedforward compensator 11 is added to the preceding stage of the integral compensator 6. Although the addition location of the output of the feedforward device 23 is changed, the order of the transfer function of the floor vibration feedforward compensator 11 is lowered by one order compared with the case of FIG. Is profitable.

For the sake of simplicity, the vibration isolation device shown in FIGS. 1 and 2 is shown for one axis in the vertical direction.
It goes without saying that the same device configuration is used in the horizontal direction. Of course, the same device configuration is applied to a multi-axis anti-vibration device including the vertical and horizontal directions. Also, FIG.
Then, the vibration isolation device using, for example, a VCM, which is a typical electromagnetic actuator, is used, but it may be a vibration isolation device in which other actuators including it are combined.

Further, in the embodiments of FIGS. 1 and 2, the control device is realized by an analog arithmetic circuit, but a part or all of this may be replaced by a digital arithmetic device such as an electronic computer. .

[0042]

According to the present invention, the following effects can be obtained.

(1) It is possible to calculate the physical parameter without arbitrariness from the measured real part curve of the frequency response, and the value can be used to set the compensation parameter of the floor vibration feedforward compensator.

(2) When mechanical control is generally performed without limiting to the control of the vibration isolation table, it is inevitable that a number of high-order resonance modes and local mechanical vibrations occur. At that time, the physical parameters should be calculated on the basis of the form of the mechanically derived low-order transfer function. Since the real part curve in the frequency response in which the identification of the main resonance mode is good is used, it is easy to accurately calculate the dynamic parameter from the data. As a result, the parameters of the floor vibration feedforward compensator can be set accurately.

(3) Therefore, there is an effect that the damping rate from floor vibration to vibration on the vibration isolation table can be increased as compared with the conventional case.

(4) Further, the above parameter setting is performed off-line. When the mechanical characteristics of the vibration isolation table are changed due to the installation conditions of the vibration isolation table, the parameter setting may be retried, and the best floor vibration feedforward can always be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a vibration isolation device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a vibration isolation device according to another embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a conventional image stabilization device using a VCM.

FIG. 4 is a frequency response gain curve.

FIG. 5 is an example of an actually measured result of inertance response.

FIG. 6 is an example of a VCM structure.

FIG. 7 is a control block diagram of a vibration isolation device using a VCM as an actuator.

FIG. 8 is a real part curve of a frequency response.

FIG. 9 is a modification of a control block diagram of a vibration isolation device using a VCM as an actuator.

[Explanation of symbols]

1: Vibration isolation table, 2: First acceleration sensor, 3: Preload mechanical spring, 4: Viscous element, 5: Filter, 6: Integral compensator,
7: power amplifier, 8: VCM, 9: second acceleration sensor, 10: filter, 11: floor vibration feedforward compensator, 12: feedback device, 13: VCM type supporting leg, 14: oscillator, 15: control signal , 16a, 16
b: electronic switch, 17: physical parameter calculation means, 1
8: compensation parameter setting means, 19: permanent magnet, 20:
Winding coil, 21: support frame, 22: fixed frame, 23: feedforward device.

Claims (5)

[Claims] 1. A voice coil motor for driving an anti-vibration table, a first acceleration sensor for detecting vibration of the anti-vibration table, an output of the first acceleration sensor converted into an electrical signal, and an appropriate filtering process. A prefilter for, an integral compensator for integrating the output of the prefilter,
And a feedback device having a power amplifier that excites the voice coil motor in response to the output signal of the integral compensator, a second acceleration sensor that detects a floor vibration on which the vibration isolation table is installed, and the second acceleration sensor. It has a filter for converting the output of the acceleration sensor into an electric signal and performing an appropriate filtering process, and an appropriate transfer function for compensating the output signal of this filter and feeding it forward to the preceding stage of the power amplifier. A vibration isolation device comprising a feedforward device having a floor vibration feedforward compensator, wherein an electronic switch for connecting and disconnecting signals in the feedback device and the feedforward device, and the vibration isolation by exciting the power amplifier. An oscillator for driving the table, an output signal of the oscillator and the pre-filler A physical parameter calculating means for calculating the mechanical physical parameters of the vibration isolation table by taking in the output signal of the vibration damping table, and the compensation for setting the compensation parameter of the floor vibration feedforward compensator based on the output of the physical parameter calculating means. An anti-vibration device comprising: parameter setting means. 2. The vibration isolator according to claim 1, wherein the transfer function of the floor vibration feedforward compensator is a transfer function in which a PI compensator and an integrator are cascade-connected or a transfer function of a double integrator. apparatus. 3. The output of the floor vibration feedforward compensator is fed forward to the front stage of the integral compensator instead of being fed forward to the front stage of the power amplifier, and the transfer function of the floor vibration feedforward compensator is PI compensated. The vibration isolation device according to claim 1, wherein the vibration isolation device is an instrument or an integral compensator. 4. The physical parameter calculation means uses the output signal of an oscillator for vibrating the vibration isolation table and the acceleration signal of the vibration isolation table driven in response to the output of the oscillator as input signals for frequency response. The data of the real part curve in is calculated, the frequency f _max giving the peak and the frequency f _min giving the bottom are detected from the data string of the real part curve, and after being confirmed, the damping coefficient ζ and the natural frequency f _n are calculated as follows: ] And a spring constant K for supporting the vibration isolation table
And viscous friction coefficient C are respectively K = 4πf _n ² M.V.
The vibration damping device according to claim 1, 2 or 3, wherein the vibration damping device is calculated based on a calculation formula of C = 4πf _n ζM. 5. An actuator for driving an anti-vibration table, an acceleration sensor provided on a floor on which the anti-vibration table is installed, a compensating means for compensating the detection signal based on a predetermined compensation parameter, and a compensating means for the compensating means. In a vibration control device including a drive unit that drives the actuator based on an output, the compensation parameter includes an oscillator for driving the actuator to apply vibration to the vibration isolation table, and the vibration isolation table provided in the vibration isolation table. Based on the acceleration sensor and the output of the acceleration sensor and the oscillator, the data of the real part curve in the frequency response when the vibration is applied is calculated, and the spring constant or the spring constant for supporting the vibration isolation table based on this is calculated. In addition to this, a means for obtaining a viscous friction coefficient and a predetermined compensation in the compensating means are performed by this spring constant or by the viscous friction coefficient in addition thereto. A vibration control device, wherein the vibration control device is set by a parameter setting means including means for setting a parameter for controlling the vibration.