JP2003021190A - Active vibration resistant device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the vibration resistant performance of an active vibration resistant device for performing floor vibration feed-forward control. SOLUTION: This active vibration resistant device is provided with a vibration resistant stand, a support mechanism for supporting the vibration resistant stand to prevent the vibration, an actuator for applying the control force to the vibration resistant stand, a displacement detecting means for detecting a displacement quantity of the vibration resistant stand in relation to the standard position thereof, a vibration measuring means for measuring the vibration of the vibration resistant stand, a speed sensor for measuring the vibration of a floor for installation of the vibration resistant stand, a first compensation unit 7 for compensating a target value of the displacement quantity of the vibration resistant stand in relation to the standard position and a differential signal of the output signal PO of the displacement detecting means for feedback to the actuator, second compensation units 9 and 12 for compensating the output signal AS and VS of the vibration measuring means for feedback to the actuator, and a third compensation unit 20 for compensating the speed signal based on the output signal FVS of the speed sensor for feedback to the actuator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active vibration isolation device including a vibration isolation table for mounting precision equipment, and more particularly to an active vibration isolation device for improving vibration isolation performance of floor vibration.

[0002]

2. Description of the Related Art In a semiconductor exposure apparatus or the like, X is placed on a vibration isolation device.
The Y stage is mounted. This vibration isolation device uses an air spring,
It plays the role of damping the vibration by the vibration absorbing means such as a coil spring and a vibration-proof rubber. However, in the passive vibration isolator equipped with these vibration absorbing means, although the vibration propagating from the floor can be attenuated to some extent, the vibration generated by the XY stage itself mounted on the vibration isolator is effective. There is a problem that it cannot be attenuated. That is, the reaction force generated by the high-speed movement of the XY stage itself causes the vibration isolator to oscillate, and this vibration significantly impairs the positioning stability of the XY stage. Further, in the passive vibration isolation device, there is a tore-off relationship between the insulation (vibration isolation) of the vibration propagating from the floor and the vibration suppression (vibration suppression) performance generated by the high speed movement of the XY stage itself. In order to solve these problems, an active vibration isolation device is often used in recent years.

The active vibration isolator comprises a vibration control loop for detecting the vibration of the vibration isolation table and feeding it back, and a position control loop for localizing the vibration isolation table at a predetermined location. The former vibration control loop is characteristic of active vibration isolation systems as opposed to passive ones.

In the case of the active vibration isolator, the skyhook damper effect and the skyhook spring effect can be realized in principle. For example, in a vibration isolation device using an air actuator, the acceleration signal is first-order integrated by the integral characteristic of the air actuator by acceleration feedback to become a dimension of velocity, and acts as damping (viscosity) as an operation amount for the mechanical system. Similarly, when velocity feedback is performed, the dimension of the position becomes a dimension due to the integral characteristic of the air actuator, and it acts as a spring (spring property) as an operation amount for the mechanical system. Therefore, the skyhook damper effect is obtained by acceleration feedback, and the skyhook spring effect is obtained by speed feedback.

By the way, most of the conventional active vibration isolation devices give an operation amount as damping to a support mechanism for a vibration isolation table by feeding back an output of an acceleration sensor which is a representative of vibration measuring means. That is, only the skyhook damper effect is used. In order to maximize the performance of the active vibration isolation device, it is desirable to use not only the skyhook damper effect but also the skyhook spring effect. At present, there are almost no active vibration isolation devices that have skyhook springs mounted together with skyhook dampers.

In Japanese Patent Application No. 11-9259 (active vibration isolator, exposure apparatus and method, and device manufacturing method), not only the skyhook damper but also the skyhook spring effect has been effectively used. A device has been proposed. This makes it essential to use a speed sensor in place of the acceleration sensor in order to realize the skyhook spring effect.

Further, in order to improve the insulation (vibration isolation) performance of the vibration propagating from the floor which is the foundation of the equipment installation, the vibration propagating from the floor to the surface plate through the support mechanism is detected and propagated through the support mechanism. The floor vibration feedforward control is used in which the vibration from the floor is canceled by causing the actuator to generate a vibration waveform opposite to the vibration waveform.

[0008]

However, the conventional floor vibration feedforward control has a problem in that sufficient floor vibration insulation (vibration isolation) performance cannot be realized yet. An object of the present invention is to improve vibration isolation performance in an active vibration isolation device using floor vibration feedforward control.

[0009]

In order to solve the above problems, the present invention performs floor vibration feedforward control using a speed sensor instead of a conventional acceleration sensor. That is, the first active vibration isolation device according to the present invention includes a vibration isolation table, a support mechanism that supports the vibration isolation table for vibration isolation, an actuator that applies a control force to the vibration isolation table, and a vibration isolation table for the vibration isolation table. Displacement detecting means for detecting a displacement amount with respect to a reference position, vibration measuring means for measuring the vibration of the vibration isolation table, and a speed sensor which is a floor vibration measuring means for measuring the vibration of the floor on which the vibration isolation table is installed. The control means for controlling the vibration isolation of the vibration isolation table compensates the difference signal between the target value of the displacement of the vibration isolation table with respect to the reference position and the output signal of the displacement detection means, and feeds it back to the actuator. Compensator, a second compensator for compensating the output signal of the vibration measuring means and feeding back to the actuator, and a speed signal based on the output signal of the speed sensor for feedforward to the actuator. Characterized by comprising a third compensator that. As the speed sensor, for example, a so-called servo type speed sensor or a geophone sensor can be used.

A second active anti-vibration device according to the present invention is the first active anti-vibration device, further comprising a plurality of active support legs for supporting the anti-vibration table at a plurality of points, and the actuators are provided with respective active support legs. Is an air actuator or a linear motor incorporated in a dynamic support leg, and each active support leg is provided with a vibration measuring means and a position measuring means for measuring the vibration and the position of the supporting point, respectively. The means is a sensor for detecting acceleration or speed, and the control means controls the drive of the actuator based on the output of the vibration measuring means to provide the damping table with an electrical damping effect and the spring effect. An acceleration / velocity feedback loop for imparting the force and a drive of the actuator based on the output of the position measuring means. A position feedback loop for positioning the vibration isolation table at a predetermined equilibrium position without steady deviation by performing control, and drives the actuator using a speed signal based on the output of the speed sensor for the floor vibration. It is characterized by performing feed-forward control to perform.

Further, a third active vibration isolator according to the present invention is, in the second active vibration isolator, a pressurization force measuring means for measuring a pressurization force of the air actuator incorporated in each active support leg. Is attached, and the control means is provided with a pressurizing force feedback loop for controlling the pressurizing force of the air actuator based on the output of the pressurizing force measuring means.

A fourth active vibration isolator according to the present invention is the active vibration isolator according to any one of the first to third aspects, wherein phase lag compensation or phase compensation is applied to the detection output of the speed sensor as the floor vibration measuring means. A first compensating means for performing advance compensation or shaping of frequency characteristics is provided, and the feedback control is performed based on an output signal of the first compensating means.

A fifth active vibration isolator according to the present invention is the active vibration isolator according to any one of the first to fourth aspects, wherein the vibration measuring means is a speed sensor for outputting a speed signal, and the second compensator is The velocity signal of the velocity sensor is compensated and fed back to the actuator.

A sixth active vibration isolator according to the present invention is, in the first to fourth active vibration isolators, a speed sensor as the vibration measuring means for detecting the speed of the vibration isolation table, and A second compensating means for performing phase lag compensation or phase lead compensation on the detection output or for shaping the frequency characteristic, and performing the feedback control based on the output of the second compensating means to remove the above It is characterized by imparting an electric spring effect to the shaking table.

[0015]

In the conventional active vibration isolator, an acceleration sensor has been used to detect floor vibration when performing floor vibration feedforward control. When an acceleration sensor is used, a floor vibration feedforward requires a second-order integral calculation on the output of the acceleration sensor to obtain an absolute displacement. When an air actuator is used, since it has an integral characteristic, the compensator needs a first-order integral operation.

Further, it is expected that the effect of feedforward to the high frequency range will be improved by using a linear motor having a better response than the air actuator. However, when the floor vibration is fed forward to the linear motor, the compensator needs to perform the second-order integral calculation.

In the vibration isolator of the present invention, a velocity sensor is used as the floor vibration measuring means used for the floor vibration feedforward control, instead of the acceleration sensor. In the floor vibration feedforward control, the absolute displacement is obtained from the output of the floor vibration measuring means, and the absolute displacement is appropriately input to the actuator, thereby suppressing the transmission of the floor vibration. Here, the second-order integral calculation is necessary to obtain the absolute displacement from the output of the acceleration sensor, but the first-order integral calculation may be used to obtain the absolute displacement from the output of the speed sensor.

By the way, the acceleration sensor is used on the premise that it can detect from DC to high frequencies, but in reality, in a structure (vibration isolation table) for vibration control, in most cases, it is extremely low. Since substantially no frequency acceleration is present, the output signal in this frequency domain is dominated by acceleration sensor noise, which is independent of structural vibration. If the noise in the extremely low frequency range is subjected to integration processing with high amplification in the low frequency range and applied to the actuator, drift or the like will occur and the posture control of the structure will become unstable. Therefore, in practice, it is necessary to perform a low-frequency cut filtering process on the acceleration signal in the low frequency range, and as a result, vibration control in the low frequency range cannot be effectively realized.

On the other hand, in the case of the present invention using a speed sensor,
The velocity in the extremely low frequency region can be detected more dominantly than the acceleration in this region, and the absolute displacement signal obtained by first-order integration can also be used as a significant signal, improving the stability of operation. As described above, the floor vibration is measured by the speed sensor and the floor vibration feedforward control is performed, so that the ability to suppress the transmission of the floor vibration (vibration isolation performance) can be improved.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a control system of an active vibration isolator according to an embodiment of the present invention, and FIG. 2 shows a configuration of a vibration isolation table and an active support leg portion of the active vibration isolator of FIG. It is a perspective view shown.

First, the structure of this active vibration isolator for controlling the movement posture of the rigid body 6 degrees of freedom will be described with reference to FIG. As shown in the figure, this active vibration isolation device has a mechanical structure for controlling the motion posture of a rigid body 6 degrees of freedom of the vibration isolation table 1 having a substantially triangular shape. In the figure, 2 is an XY stage mounted on the vibration isolation table 1 and 3 (3-1, 3-2 and 3-).
3) is an active support leg that supports the vibration isolation table 1. In one active support leg 3, the acceleration sensor AS and the speed sensor VS, which are vibration measuring means, and the positions as position measuring means, which are necessary to control the two axes of the vertical direction and the horizontal direction, are provided. A sensor PO, a pressure sensor PR, a servo valve SV and an air actuator are built in. "A in the figure
The symbols attached to the symbols such as "S" and "PO" indicate the azimuth according to the coordinate system in the figure and the location of the active support leg 3. For example, "Y2" refers to the active support leg 3-2 arranged on the left side in the Y-axis direction. Further, 4 is a floor on which a vibration isolation device is installed, and is a speed sensor FV which is a floor vibration measuring means for measuring the vibration of the floor near the active support legs on the floor.
S are mounted in the required number for controlling the two axes of the vertical direction and the horizontal direction.

Next, referring to FIG. 1, the active vibration isolator will be described.
The configuration of the control system will be described. Position sensor PO (PO-Z
1, PO-Z2, PO-Z3, PO-X1, PO-Y2
And the output of PO-Y3) is the output of the position target value output unit 5.
(Z_Ten, Z₂₀, Z₃₀, X_Ten, Y_{2 0}, Y₃₀),
Position deviation signal (e_z1， E_z2， E_z3， E_x1， E_y2， E_y3)
Becomes These deviation signals correspond to the translational motion of the vibration isolation table 1 and
Motion mode position with a total of 6 degrees of freedom with rotational motion around the axis
Deviation signal (e_x， E_y， E_zEq_xEq_yEq_z) Is calculated and output
Guided to the motion mode extraction calculation means 6 regarding the position signal
It The signal output is almost non-interfering for each motion mode.
Gain compensator 7 for position signal for adjusting position characteristics
(First compensator). Position this loop
It is called a dback loop.

Next, the acceleration sensor AS (AS-Z1, AS
-Z2, AS-Z3, AS-X1, AS-Y2 and A
S-Y3) and speed sensor VS (VS-Z1, VS-
Z2, VS-Z3, VS-X1, VS-Y2 and VS
A feedback loop based on the output of -Y3) will be described. The speed sensor VS is a sensor that can detect speed. The acceleration signal is ideally passed through an integrator, and actually, a pseudo integrator is used to open the velocity signal, which is different from the principle of outputting the speed signal.
It is premised that it is disclosed in Japanese Patent Publication (servo-type geophone), a power generation type utilizing relative motion of a permanent magnet and a coil, and the like. A floor speed sensor FVS (FVS
-Z1, FVS-Z2, FVS-Z3, FVS-X1,
The same applies to FVS-Y2 and FVS-Y3).

The acceleration signal from the acceleration sensor AS is subjected to appropriate filtering processing such as removal of high frequency noise as necessary, and is input to the motion mode extraction means 8 relating to the acceleration signal. Its output motion mode acceleration signals _{(a x, a y, a} z, aq x, aq y, aq z) becomes. The motion mode acceleration signal is guided to the gain compensator 9 (second compensator) for the acceleration signal at the next stage so that the optimum damping is set for each motion mode. By adjusting this gain, optimum damping characteristics can be obtained for each motion mode.

The speed signal from the speed sensor VS is required
Depending on the appropriate filter filter, such as removing high frequency noise.
Motion mode extraction means for the velocity signal
Input to 10. Its output is the motion mode velocity signal
(V_x, V_y, V_z, Vq_x, Vq _y, Vq_z). However
Before the motion mode extraction means 10 relating to the speed signal
The speed output of the speed sensor VS.
Signal phase compensator 11 (second compensator) is inserted.
Has been. The motion mode velocity signal is maximum for each motion mode.
The speed signal of the next stage should be
To the gain compensator 12 (second compensator). This
By adjusting the gain of the
Ihook spring can be realized. Acceleration signal
Of the gain compensator 9 (second compensator) and the speed
Of the gain compensator 12 (second compensator) regarding the frequency signal
The force is added for each motion mode, and the force is added before the PI compensator 13.
Be fed back to. This feedback loop
We will call it the acceleration / velocity feedback loop.

Here, the phase compensator 11 for the velocity signal
The role of (second compensation means) will be described. The phase compensator 11 for the speed signal is used to reduce the gain of the speed sensor VS having a band-pass type frequency characteristic, particularly in the low frequency range, and to advance the phase advance in the low frequency range paired with such gain characteristic. It is inserted in the latter stage of the speed output in consideration of the one. The compensation in the phase compensator 11 for the speed signal is phase lag compensation or phase lead compensation. Alternatively, without inserting the phase compensator 11, the gain and phase characteristics of the output itself of the speed sensor VS in the low frequency range have appropriate frequency characteristics so as not to cause instability due to the feedback of the speed output. You may make compensation.

The output of the gain compensator 7 for the position signal
And the negative feedback signal of the acceleration / velocity feedback loop is
The motion mode drive signal is added and passes through the PI compensator 13.
(D _x, D_y, D_z, Dq_x, Dq_y, Dq_z), And for each axis
In order to obtain the driving force that the actuator should generate,
It is guided to the motion mode distribution calculation means 14, and its output is for each axis.
Drive signal (dz₁, Dz₂, Dz₃, Dx₁, Dy₂, D
y₃). This drive signal is added to each axis.
Input to the pressure feedback loop.

Regarding the principle of pressure feedback,
It is disclosed in Japanese Patent Laid-Open No. 10-256141 (active vibration isolation device). Briefly, in this pressure feedback loop, the pressure measuring means (pressure sensor) PR for measuring the internal pressure of the air actuator is used.
(PR-Z1, PR-Z2, PR-Z3, PR-X1,
The outputs of PR-Y2 and PR-Y3) are led to the pressure detection means 15 which performs filtering for appropriate amplification and high frequency noise removal, and this output is applied to the PI relating to the pressure signal.
Feedback is provided to the front stage of the compensator 16 (fourth compensator).

The output of the PI compensator 16 relating to the pressure signal is input to a voltage-current converter (abbreviated as VI conversion in the figure) 17 for opening and closing the servo valve SV. A bias voltage for determining the neutral position of the air actuator is applied from the target pressure value output unit 18 to the preceding stage of the PI compensator 16 regarding the pressure signal. In this pressing force feedback loop, the internal pressure of the air actuator is detected and fed back by the pressing force measuring means PR typified by a pressure sensor. However, the load generated by the air actuator is typified by the load sensor. The function similar to the above-mentioned pressure feedback loop can be realized also when the load feedback is constructed by negatively feeding back this output detected by the measuring means. That is, here, the technical content is described using the pressure feedback loop in the pressurization force feedback loop.

Next, a floor velocity sensor FVS (FVS, which is a floor vibration measuring means, is newly installed in this embodiment.
-Z1, FVS-Z2, FVS-Z3, FVS-X1,
FVS-Y2 and FVS-Y3) will be described. The velocity signal from the floor velocity sensor FVS is subjected to appropriate filtering processing such as removal of high frequency noise as necessary, and is input to the phase compensator 19 regarding the floor velocity signal. The phase compensator 19 (first compensating means) for the floor velocity signal is used to reduce the gain in the output of the floor velocity sensor FVS having a bandpass frequency characteristic, especially in the low frequency range, and to compare with such gain characteristic. It is based on how to advance the phase in the low frequency region, and the compensation is phase delay compensation or phase advance compensation. Alternatively, instead of using the phase compensator 19, the low-frequency gain and phase characteristics of the output itself of the floor speed sensor FVS may be compensated so as to have appropriate frequency characteristics.

The output of the phase compensator 19 relating to the floor velocity signal is the floor vibration compensator 2 used for the floor vibration feedforward.
0 (third compensator). In this embodiment, for example, an integrator can be used as the floor vibration compensator 20. Therefore, the floor vibration compensator 20 performs an integral operation on the input signal. The output is the linear motor LM (LM-Z1, LM-Z2, LM-Z
3, LM-X1, LM-Y2, LM-Y3) is an input to the driver 21 which supplies a current. Floor vibration compensator 20
The floor vibration transmitted to the anti-vibration table can be suppressed by properly adjusting. Further, the output of the phase compensator 19 is processed by a floor vibration compensator different from the floor vibration compensator 20 and added to the voltage / current converter 17, and the servo valves SV (SV-Z1, SV).
V-Z2, SV-Z3, SV-X1, SV-Y2, SV
In some cases, a method (not shown) for controlling -Y3) is effective. In this case, it is advantageous that the floor vibration compensator does not require integration. Further, a method (not shown) of controlling both the frequency regions such as SV for the low frequency region and LM for the high frequency region is also possible.

The superiority of the floor vibration feedforward control by the speed sensor will be described with reference to FIGS. 3 and 4. FIG. 3 illustrates the configuration of this embodiment, and FIG. 4 illustrates a part of the conventional configuration with one axis.

FIG. 3 shows the configuration when floor vibration feedforward control using a speed sensor is performed. The output signal of the acceleration / speed feedback loop is input to the PI compensator 16, and the output of the PI compensator 16 is the VI converter 1.
7 and the output of the VI converter 17 is the servo valve SV.
Entered in. Further, the signal of the pressure sensor PR is appropriately processed by the pressure detection means 15 and fed back to the input of the PI compensator 16. Further, a bias voltage for determining the neutral position of the air actuator is input from the target pressure value output unit 18. The output of the floor velocity sensor FVS is phase-compensated by the phase compensator 19 relating to the floor velocity signal and then input to the floor vibration compensator 20.
Is the input of the driver 21. Speed sensor FVS
In order to obtain the absolute displacement signal as the floor vibration feedforward control output from the output of the above to the linear motor LM, the floor vibration compensator 20 needs the integral calculation of the first floor.

FIG. 4 shows a conventional configuration in which floor vibration feedforward control using an acceleration sensor is performed. The configurations of the acceleration, velocity feedback loop, and pressure feedback are the same as in FIG. In FIG. 4, floor vibration is detected by the floor acceleration sensor FAS. The output of the floor acceleration sensor FAS is input to the floor vibration compensator 20, and the output of the floor vibration compensator 20 becomes the input of the driver 21. In order to obtain an absolute displacement signal from the output of the acceleration sensor to the floor vibration feedforward control output to the linear motor, the second-order integral calculation by the floor vibration compensators 20-1 and 20-2 is required.

By the way, the acceleration sensor is used on the premise that it can detect from DC to high frequencies, but in reality,
In a structure (vibration isolation table) to which vibration is controlled, extremely low frequency acceleration does not substantially exist in most cases.
The output signal in this frequency domain is dominated by the noise of the acceleration sensor, which is independent of the vibration of the structure. If the noise in the extremely low frequency range is subjected to integration processing with high amplification in the low frequency range and applied to the actuator, drift or the like will occur and the posture control of the structure will become unstable. Therefore, in practice, it is necessary to perform a low-frequency cut filtering process on the acceleration signal in the low frequency range, and as a result, vibration control in the low frequency range cannot be effectively realized.

Therefore, according to the configuration of the present invention, the effect of the floor vibration feedforward control is improved by avoiding the above-mentioned instability factor by detecting the floor vibration by the speed sensor instead of the acceleration sensor. When the velocity sensor is used, the velocity in the extremely low frequency region can be detected more dominantly than the acceleration in this region, and the integral calculation for obtaining the absolute displacement signal can be performed on the first floor. That is, by using the speed sensor, it is possible to suppress the occurrence of drift or the like due to the floor vibration feedforward control. Therefore, in the floor vibration feedforward control using the speed sensor, the stability in the low range is improved as compared with the case where the acceleration sensor is used, and the effect of floor vibration insulation in a wider band can be obtained.

[0037]

In the active vibration isolator, the floor vibration feedforward control is used in order to improve the insulation (vibration isolation) performance of the vibration propagating from the floor. Conventionally, an acceleration sensor has been used as a vibration measuring means used for floor vibration feedforward control. However, to use for floor vibration feedforward, 2
Integral calculation of the floor is required. Since the output of a commonly used acceleration sensor contains a drift and a noise component in a low frequency range, the influence of these factors is greatly exerted by the second-order integration calculation.

Therefore, in the present invention, a speed sensor is used as the vibration measuring means used for the floor vibration feedforward control. Compared to the acceleration sensor, the speed sensor has less noise in the low frequency range, and since the floor vibration feedforward control can be realized by the integration calculation on the first floor, it is more stable operation against the noise in the low frequency range. Is possible. From the above, the floor vibration feedforward control using the speed sensor can improve the insulation performance of the floor vibration.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a mechanical structure of the active vibration isolator of FIG.

FIG. 3 is a diagram showing a configuration of floor vibration feedforward control using a speed sensor according to the present invention.

FIG. 4 is a diagram showing a configuration of a floor vibration feedforward control using a conventional acceleration sensor.

[Explanation of symbols]

1: Vibration isolation table, 2: XY stage, 3: Active support leg,
4, floor, 5: position target value output unit, 6: motion mode extraction / calculation unit for position signal, 7: gain compensator (first compensator) for position signal, 8: motion mode extraction / calculation unit for acceleration signal, 9: gain compensator for acceleration signal (second compensator), 10: motion mode extraction calculation means for velocity signal, 11: phase compensator for velocity signal (second compensator), 12: gain compensation for velocity signal Device (second compensator), 13: PI compensator, 14: motion mode distribution calculating means, 15: pressure detecting means, 16: PI compensator (fourth compensator) for pressure signal, 17: voltage-current conversion 18: Pressure target value output unit, 19: Phase compensator (first compensator) for floor velocity signal, 20: Floor vibration compensator (third compensator), 21: Driver, PO: Position sensor, AS: Speed sensor, VS: speed sensor, P
R: pressure sensor, FVS: floor speed sensor, SV: servo valve, LM: linear motor.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shinji Wakui             Kyano, 3-30-2 Shimomaruko, Ota-ku, Tokyo             Within the corporation (72) Inventor Michio Yanagisawa             Kyano, 3-30-2 Shimomaruko, Ota-ku, Tokyo             Within the corporation F term (reference) 3J048 AB09 AB11 AD03 DA01 EA13                 5F046 AA23 DA30 DB14

Claims (7)

[Claims] 1. An anti-vibration table, a support mechanism for supporting the anti-vibration table in a vibration-proof manner, an actuator for applying a control force to the anti-vibration table, and a displacement detection for detecting a displacement amount of the anti-vibration table with respect to a reference position. Means, a vibration measuring means for measuring the vibration of the vibration isolation table, a speed sensor for measuring the vibration of the floor on which the vibration isolation table is installed, a target value of the displacement amount of the vibration isolation table with respect to a reference position, and the displacement A first compensator for compensating the difference signal of the output signals of the detecting means and feeding back to the actuator;
A second compensator for compensating the output signal of the vibration measuring means and feeding back to the actuator, and a third compensator for compensating the speed signal based on the output signal of the speed sensor and feeding forward to the actuator. An active vibration isolation device characterized by being provided. 2. An air actuator is used as the actuator, and a pressing force measuring unit that measures a pressing force of the air actuator with respect to the vibration isolation table, and an output signal of the pressing force measuring unit is compensated to the air actuator. The active vibration isolator according to claim 1, further comprising: a fourth compensator for feedback. 3. The actuator according to claim 1, wherein a plurality of types of actuators including a linear motor are used as the actuator, and a speed signal based on an output signal of the speed sensor is fed forward to the linear motor.
The active vibration isolator according to 1. 4. A first compensating means for compensating a phase delay or a phase lead with respect to an output signal of the speed sensor or shaping a frequency characteristic, according to any one of claims 1 to 3. The active vibration isolator according to one. 5. The vibration measuring means outputs a speed signal,
5. The active vibration isolator according to claim 1, wherein the second compensator compensates the velocity signal of the vibration measuring means and feeds it back to the actuator. 6. The vibration measuring means outputs an acceleration signal and a speed signal, and the second compensator compensates the acceleration signal and the speed signal of the vibration measuring means, respectively, and feeds them back to the actuator. The active vibration isolator according to any one of claims 1 to 4. 7. The second compensating means for performing phase delay compensation or phase lead compensation or shaping of frequency characteristics for the speed signal of the vibration measuring means, according to claim 5 or 6. Active vibration isolation device.