JP3507234B2 - Active vibration isolation device and active vibration isolation method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention can improve the vibration damping performance without impairing the vibration isolation performance. In particular, the transmission characteristics of vibration from the equipment installation foundation such as a floor can be significantly improved as compared with the conventional one. The present invention relates to an improved active vibration isolation device and active vibration isolation method for mounting on precision equipment such as a semiconductor exposure apparatus.

[0002]

2. Description of the Related Art As precision instruments such as electron microscopes and semiconductor exposure apparatuses have become more precise, higher performance of precision vibration isolation devices equipped with them has been required. Particularly, in a semiconductor exposure apparatus, in order to perform appropriate and quick exposure, a vibration isolation table that eliminates external vibrations including vibrations from the equipment installation foundation such as a floor is necessary. This is because it is necessary to prevent vibration that adversely affects the exposure from occurring on the exposure stage.

Further, in a semiconductor exposure apparatus characterized by an intermittent operation called step-and-repeat, an XY for exposure is used.
Repeated step motion of the stage excites vibration of the vibration isolation table. Therefore, the anti-vibration table has anti-vibration performance against external vibration including vibration from the equipment installation foundation such as floor.
It is required to achieve a well-balanced damping performance against vibrations generated by the operation of the equipment mounted on the vibration isolation table.

There is also a semiconductor exposure apparatus that employs a scan exposure method as an alternative to step-and-repeat. In this apparatus as well, vibration transmitted from the outside such as vibration from the equipment installation foundation is removed as much as possible. It is necessary to instantly suppress the vibration of the vibration isolation table excited by the scanning operation of the exposure stage. In particular, in a scan exposure device, since exposure is performed while the exposure stage is performing a scanning operation, vibration isolation performance against external vibration and vibration suppression performance against vibration generated by the operation of the equipment mounted on the vibration isolation table are required. The demands for are highly demanded, and higher-performance vibration isolation devices have become indispensable.

In response to such a demand, the vibration of the vibration isolation table is detected by a vibration sensor, the output signal of the vibration sensor is compensated, and the vibration signal is fed back to an actuator that applies a control force to the vibration isolation table. An active vibration isolation device that controls vibration of a vibration isolation table has been put into practical use. The active vibration isolation system enables a well-balanced realization of vibration isolation performance and vibration control performance, which was difficult with the conventional vibration isolation system composed of only passive vibration isolation elements such as springs and dampers. .

Further, in response to the higher precision of the equipment mounted on the vibration isolation table, in the active vibration isolation device, the vibration of the equipment installation foundation such as the floor is detected, and the compensation signal is used to detect the vibration from the equipment installation foundation. A method of controlling the actuator to reduce the vibration transmissibility and a method of controlling the actuator to cancel the driving reaction force based on the drive signal of the equipment mounted on the vibration isolation table have been proposed. The performance of the shaking device has improved dramatically.

Among these control methods, the method of controlling the actuator acting on the vibration isolation table by the vibration compensation signal of the equipment installation foundation significantly improves the insulation performance of the equipment installation foundation vibration as compared with the conventional method. Higher definition of semiconductor exposure equipment and relaxation of vibration standard of equipment installation foundation.

As a method of controlling the active vibration isolator based on the compensation signal of the equipment installed basic vibration, for example, Japanese Patent Laid-Open No. 263868/1993 "Method for controlling ground motion disturbance of vibration isolation table" includes actuator characteristics. There is also disclosed a method of performing control using a device installation fundamental vibration compensator designed based on some measured characteristics of an active vibration isolation device. The method disclosed in the publication uses an apparatus installation basic vibration compensator that directly reflects the characteristics of an actual apparatus, and thus an active vibration isolation system composed only of a control loop that feeds back the vibration of a conventional vibration isolation table. Compared with the vibration device, the insulation performance of the device installation fundamental vibration can be greatly improved.

[0009]

Several proposals have been made for the active vibration isolation device and the control method thereof, which include the method described in the above-mentioned publication, for performing vibration control based on the compensation signal of the device installation basic vibration. ing. By the way, in these devices and their control methods, the device installation fundamental vibration is generally treated as translational vibration. Translational vibration is usually dominant in vibrations of equipment installation foundations such as floors. Therefore, conventionally, in this type of device, control was performed by considering the device installation foundation vibration as translational vibration.

For example, in the apparatus disclosed in Japanese Unexamined Patent Publication No. Hei 5-99271, "Method for active control of vibration isolation table", a relative displacement signal between the vibration isolation table and the equipment installation foundation is detected by a displacement sensor, and the output signal From the acceleration detection signal of the equipment installation foundation, the acceleration signal of the vibration isolation table is derived by calculation, and this is used to control the vibration of the vibration isolation table.

In the device disclosed in the above publication, the basic vibration of the device installation is regarded as translational vibration of horizontal and vertical three degrees of freedom, these are detected by three acceleration sensors, and the detection signal and the vibration isolation table are arranged in each part. Based on the vibration isolation table detected by the displacement sensor and the relative displacement signal of the equipment installation foundation, the acceleration sensor detects the vibration of the equipment installation foundation by calculating the acceleration of each part of the vibration isolation table. Have reduced to only. In this device and control method, it is premised that the device installation fundamental vibration is mainly a translational vibration. As described above, in the conventional active vibration isolator of this type, it is general to treat the basic vibration of the device installation as a vibration of translational 3 degrees of freedom with horizontal 2 degrees of freedom and vertical 1 degree of freedom.

Even in the conventional active vibration isolator, depending on the device configuration, there is a device capable of controlling the influence of the rotational vibration of the device installation foundation on the vibration isolation table, but the influence of the rotational vibration component of the device installation foundation is emphasized. However, there has been no apparatus and method for controlling appropriately by paying attention to its control performance.

However, depending on the structure of the building in which the device is installed, the device installation foundation vibration may include a rotational vibration component, and even if vibration control is performed by considering only the translational vibration of the device installation foundation, In some cases, a sufficient vibration isolation effect cannot be obtained. Many precision instruments mounted on a vibration isolation table especially hate rotational vibration, and in a vibration isolation table mounted with such a device, insulation of rotational vibration of the equipment installation foundation becomes a big problem. Therefore, it is indispensable to improve the insulation performance of rotary vibration of the equipment installation foundation, which has not been sufficiently considered in the past, to the same level as or higher than the insulation performance of translational vibration.

[0014]

In order to solve the above problems SUMMARY OF THE INVENTION, active anti-vibration apparatus of the present invention, the anti-vibration table, before Kijo isolation base
It includes a plurality of actuators for applying a force, the pre Kijo vibration table
A plurality of first detecting the vibration of the foundation device that is installed
A vibration detecting means, based on an output signal of said plurality of first vibration detection unit, extracts a vibration signal of the rotational movement mode of the base, <br/> based on said vibration signal of the rotational motion mode And a control means for controlling the plurality of actuators. The control means controls the output signals of the plurality of vibration detection means.
Based on the number, each movement including the rotational movement mode of the foundation
The vibration signal of each mode is extracted and the vibration signal of each motion mode is extracted.
For controlling the plurality of actuators based on
Is desirable.

Further, the active vibration isolation system is provided on the vibration isolation table.
When a plurality of second vibration detection means for detecting vibration are provided
Moni, wherein said control means further on the basis of the output signal of the plurality of second vibration detection unit, extracts a vibration signal for each motion mode of the anti-vibration table, said the vibration signal for each motion mode
It is desirable to control the plurality of actuators based on the above.

Further, the control means is provided with a plurality of displacement detection means for detecting a displacement amount of the vibration isolation table with respect to a reference position.
Further based on the output signals of the plurality of displacement detection means
Or be one that controls the plurality of actuators Te, based on the output signal of the plurality of displacement detection means to extract a displacement signal of the motion mode of the anti-vibration table, based on the displacement signals of the respective motion modes It may be one that controls the plurality of actuators.

Further, the plurality of actuators, electrodeposition magnetic <br/> drive Dori linear motors and pneumatic control actuator
At least one can be included.

Further, the abovepluralFirst vibration detecting meansOh
AndThe abovepluralSecond vibration detecting meansAt least one of
Can use an acceleration sensor.

[0019]

According to the present invention, apparatus is installed, including a vibration isolation table
Vibration of the foundation is detected by a plurality of first vibration detecting means,
From these output signals, the vibration signal of the rotary motion mode of the foundation is extracted and based on the vibration signal of the rotary motion mode.
Te, control a plurality of actuators for applying a force to said anti-vibration table
Control . The rotary motion mode of the foundation or this rotary motion
The vibration signal of each motion mode including
Therefore, it is preferable to use it to control the actuators.
Good

The actuator for applying a control force to the vibration isolation table is an electromagnetically driven actuator such as a voice coil motor, or a pneumatic control type actuator for controlling the generated force by adjusting the internal pressure of an air spring with a servo valve, Alternatively, both of them can be used.

[0021] In addition the present invention, the vibration isolation table of the vibration detected by the plurality of second vibration detection unit, extracts a vibration signal for each motion mode of the anti-vibration table from these detection signals, Re their
Controlling said plurality of activator <br/> Yueta based on Luo vibration signal for each motion mode.

Even if the vibration signal of each motion mode such as translation and rotation of the equipment installation foundation is compensated for each motion mode, signals are exchanged between each motion mode considering the coupled vibration of the vibration isolation table. It may be one that does. Desirably, in consideration of the mechanical characteristics of the active vibration isolation device, the characteristics of each motion mode of the basic vibration of the device installation to the thrust, the moment to which they act on the vibration isolation table, and the characteristics of the actuator, Compensation calculation is performed after designing and adjusting considering interaction and coupled vibration.

As a result, it is possible to greatly improve the translational vibration of the equipment installation foundation and the insulation performance of the rotation vibration of the equipment installation foundation, which was difficult to sufficiently secure by the conventional control system of this kind. , It is possible to contribute to the performance improvement of the precision equipment mounted on the vibration isolation table.

[0024]

DETAILED DESCRIPTION OF THE INVENTION

[Embodiment 1] FIG. 1 is a configuration diagram of an active vibration isolator according to a first embodiment of the present invention, and is a view best showing the features of the present invention. Hereinafter, this device will be described with reference to FIG. Although this device is a vibration isolator that acts in the horizontal direction, the means detailed below may be applied to an active vibration isolator that acts in the vertical direction.

Further, this apparatus controls the movement of three degrees of freedom in the horizontal plane, that is, the horizontal translation two degrees of freedom and the rotation about the vertical axis of one degree of freedom, and the remaining three degrees of freedom rigid body movement. It is also possible to combine a device for controlling the mode, that is, the vertical translation 1 degree of freedom and the rotation about the horizontal axis 2 degrees of freedom.

Further, like the present apparatus, not only the control of the movement of the three degrees of freedom in the horizontal plane, but also the apparatus of controlling the movement mode of the six degrees of freedom including the translational and rotational three degrees of freedom in the same manner as the present apparatus. Methods are also included in the invention.

As shown in FIG. 1, the active vibration isolator comprises an anti-vibration table 1 on which precision equipment such as a semiconductor exposure apparatus is mounted, a supporting means for supporting the same to prevent vibration, and an active anti-vibration table 1. Active vibration isolation mount 2 with actuator for applying control force
a, 2b, 2c, 2d, first for detecting the vibration of the vibration isolation table 1
Vibration isolation table vibration motion mode for extracting vibration signals of motion modes such as translation and rotation of the vibration isolation table 1 from the output signals of the vibration detection means 3a, 3b, 3c and the first vibration detection means 3a, 3b, 3c. Extraction circuit 4, vibration isolation table vibration motion mode extraction circuit 4
Second vibration detecting means 7 for detecting the vibration of the vibration isolation table vibration compensating circuit 5 that performs appropriate compensation calculation processing on the vibration signal of each motion mode of the vibration isolation table 1 extracted in Step 2, and the vibration of the device installation foundation 6 such as the floor.
a, 7b, 7c, second vibration detecting means 7a, 7b, 7c
Of the device installation foundation 6 extracted by the device installation foundation vibration motion mode extraction circuit 8 and the device installation foundation vibration motion mode extraction circuit 8 for extracting the vibration signal of each motion mode such as translation and rotation of the device installation foundation 6 from the output signal of Thrust command signal of each motion mode obtained as the output of the device installation basic vibration compensation circuit 9, the vibration isolation table vibration compensation circuit 5 and the device installation basic vibration compensation circuit 9 that perform appropriate compensation calculation processing on the vibration signal of each motion mode ,
The moment command signal is transmitted to the drive circuits 11a, 11b, 11
c, 11d, the thrust distribution circuit 10, and the active vibration isolation mounts 2a, 2b, 2 based on the output of the thrust distribution circuit 10.
The drive circuits 11a, 11b, 11c, 11d, etc. for driving the actuators incorporated in c and 2d.

Active vibration isolation mounts 2a, 2b, 2c, 2d
Is provided with a spring for supporting the vibration isolation table 1 for vibration isolation, a damper element, an actuator for applying an active control force to the vibration isolation table 1, and the like,
They are mechanically arranged in series or in parallel between the equipment installation base 6 and the vibration isolation table 1. As an actuator that is incorporated in the active vibration isolation mounts 2a, 2b, 2c, 2d and applies an active control force to the vibration isolation table 1, for example, an electromagnetically driven actuator such as a voice coil motor, or an internal pressure of an air spring is used as a servo valve. It is possible to use an air pressure control type actuator that controls the generated force, or both of them by adjusting with, for example. When a pneumatic control type actuator is used as the actuator, it can also be used as a spring or a damper element for supporting the vibration isolation table 1.

An acceleration sensor can be used for the first vibration detecting means 3a, 3b, 3c and the second vibration detecting means 7a, 7b, 7c.

This active vibration isolator comprises a vibration isolation loop for compensating the vibrations of the vibration isolation table 1 and a vibration compensation loop for the vibration isolation table 1. 1
It consists of a device installation basic vibration compensation loop that controls the vibration by focusing on the vibration transmission to the device. The configuration and operation of this vibration isolation table vibration compensation loop are as follows. That is, the vibrations of the vibration isolation table 1 supported by the active vibration isolation mounts 2a, 2b, 2c, 2d are detected by the first vibration detection means 3a, 3b, 3c such as an acceleration sensor and detected. The vibration isolation table 1 is extracted from the signal by the vibration isolation table vibration motion mode extraction circuit 4.
Extract the vibration signal of each motion mode such as translation and rotation of
In the vibration isolation table vibration compensation circuit 5, an appropriate compensation calculation process is applied to the vibration signal of each motion mode of the vibration isolation table 1. Then, it is added with a compensation signal for vibration of each motion mode such as translation and rotation of the device installation foundation 6 which will be described later in detail, and this signal is distributed to the drive circuits 11a, 11b, 11c, 11d by the thrust distribution circuit 10, It controls the actuators incorporated in each active vibration isolation mount 2a, 2b, 2c, 2d.

The active vibration isolation mounts 2a, 2b, 2c are provided with displacement detecting means for detecting the relative displacement of the vibration isolation table 1 with respect to the reference position, compensating the signal of the displacement detecting means.
The present invention also includes an active vibration isolation device having a vibration isolation table displacement control loop that feeds back to the actuator incorporated in 2d. Also, regarding the vibration isolation table displacement control loop,
Displacement signals of each motion mode such as translation and rotation of the vibration isolation table 1 are extracted from the displacement signals of the vibration isolation table 1 detected by the plurality of displacement detection means with respect to the reference position, and the signals are appropriately compensated.
It is desirable that the compensation signal of each motion mode obtained thereby be distributed to each active vibration isolation mount and controlled.

Next, the device installation basic vibration compensation loop will be described.

The apparatus installation foundation vibration compensating loop is provided for the second vibration of the apparatus installation foundation 6 such as the floor on which the active vibration isolator is installed.
Of the vibration detection means 7a, 7b, 7c, and the detection signals from the vibration detection means 7a, 7b, 7c are used to extract the vibration signals of the respective motion modes such as translation and rotation of the device installation foundation 6 in the device installation foundation vibration motion mode extraction circuit 8. In the installation foundation vibration compensation circuit 9, appropriate compensation calculation processing is performed on the vibration signal of each motion mode of the apparatus installation foundation 6. Then, the above-described vibration compensation signals for each motion mode such as translation and rotation of the vibration isolation table 1, that is, the output signal of the vibration isolation table vibration compensation circuit 5, is added for each motion mode, and this is added to the thrust distribution circuit 10. Drive circuit 11
a, 11b, 11c, 11d and controls the actuators incorporated in the active vibration isolation mounts 2a, 2b, 2c, 2d.

The operation formulas of the motion mode extraction performed by the vibration isolation table vibration motion mode extraction circuit 4, the device installation basic vibration motion mode extraction circuit 8 and the thrust distribution circuit 10 are calculated by the first vibration detection means 3a, 3b. 3c, second vibration detecting means 7
a, 7b, 7c and active vibration isolation mounts 2a, 2b, 2
It is determined based on the geometrical arrangement relationship of c and 2d.

For example, the first vibration detecting means 3a, 3b,
It is assumed that 3c is arranged as shown in FIG. At this time, assuming that the vibration detection directions of the first vibration detection means 3a, 3b, 3c are the directions of arrows 80, 81, 82, respectively, the vibration signals α ₁ , α ₂ , α ₃ detected by them are vibration-isolated. Stand 1
Translational components α _x , α _{Y in} two horizontal directions X and Y orthogonal to each other
And the rotational vibration component of θ _Z around the vertical axis orthogonal to the horizontal plane.

[0036]

[Outer 1] Is expressed by the equation (1). Here, the positional relationship between the origin O of the coordinate system and the first vibration detecting means 3a, 3b, 3c is assumed to be as shown in FIG.

[0037]

[Equation 1] Therefore, the signal of the vibration component of each motion mode is calculated by the inverse matrix of the equation (1).

[0038]

[Equation 2] Can be derived as shown in Equation 3.

[0039]

[Equation 3] Note that, here, the first vibration detection means 3a, 3b, 3c
The calculation formula for extracting the vibrations of the translational and rotational motion modes in the horizontal plane of the vibration isolation table 1 was shown from the output signal of 1. Can be derived, and an arithmetic expression for extracting the vibration of the motion mode of the rigid body 6 degrees of freedom can be derived.

Further, in Japanese Patent Application Laid-Open No. 7-83276, “Control device for vertical direction air spring type vibration isolation table”, in addition to the rigid vibration components of three degrees of freedom as described above, from the output of four sensors, Although the method of deriving the non-rigid body vibration component of the main body is disclosed, the device of the present invention may perform the same calculation. Further, here, the distance between the origin O of the coordinate system and the detection axis of each vibration detecting means is assumed to be 1 as shown in FIG. 2, but it can be derived similarly in other cases as well.

Similarly to this, the second vibration detecting means 7
From a, 7b, 7c, it is possible to derive the vibration of each motion mode such as translation and rotation of the device installation foundation. For example, the second vibration detection means 7a, 7b, 7c are arranged as shown in FIG. 3, and their vibration detection directions are indicated by arrows 83, respectively.
If the directions are 84 and 85, the translational vibration components α _x0 and α _{y0 in the} two horizontal directions X and Y orthogonal to the device installation foundation 6 are assumed.
And the rotational vibration component of θ _z around the vertical axis

[0042]

[Outside 2] Can be derived from the vibrations α ₁₀ , α ₂₀ and α ₃₀ detected by the second vibration detecting means 7a, 7b and 7c by the arithmetic expression of Formula 4.

[0043]

[Equation 4] Note that, here, the distance between the origin O of the coordinate system and the detection axis of each vibration detection means is assumed to be 1 as shown in FIG. 3, but it can be derived similarly in other cases as well.

The arithmetic expression of the thrust distribution circuit 10 is determined by the geometrical arrangement relationship of the actuators incorporated in the active vibration isolation mounts 2a, 2b, 2c and 2d.

For example, the active vibration isolation mounts 2a, 2b, 2
It is assumed that c and 2d are arranged as shown in FIG. At this time, the actuator 12 which is incorporated in the active vibration isolation mounts 2a, 2b, 2c, 2d and applies a control force to the vibration isolation table 1
a, 12b, 12c, the direction of action of the 12d is assumed to be the direction of the respective arrows 86,87,88,89, their occurrence thrust _{F a, F b, F c} , and F _d, according to their resultant force, divided The relationship between the translational thrusts F _x and F _{y in} the two horizontal directions X and Y acting on the center of gravity G of the shaking table 1 and the rotational moment M _z about the vertical axis θ _z is as shown in Formula 5.

[0046]

[Equation 5] Therefore, this inverse equation

[0047]

[Equation 6] According to the translational thrusts F _x and F _{y in the} two horizontal directions X and Y,
The control signal of the rotation moment M _z about the vertical axis θ _z is
The actuators 12a, 12b, 12c, 12d can be distributed to each actuator incorporated in the active vibration isolation mounts 2a, 2b, 2c, 2d. In addition,
Here, the center of gravity G of the vibration isolation table 1 and each actuator 12a,
The distance between the action axes of 12b, 12c and 12d is 1 as shown in FIG. 4, but it can be derived in the same manner in other cases as well.

In the vibration isolation table vibration compensation circuit 5 and the apparatus installation basic vibration compensation circuit 9, compensation calculation is performed for each motion mode. As the compensation calculation, PI compensation (proportional / integral compensation), gain compensation, integral compensation, or a combination thereof is applied. Depending on the arrangement of the active anti-vibration mounts 2a, 2b, 2c, 2d and the position of the center of gravity of the anti-vibration table 1, mutual motion modes may be coupled with each other. Considering Figure 5
It is desirable to perform a compensation calculation having interference terms between the respective motion modes as shown in FIG. FIG. 5 shows translation X as an example.
It is assumed that the mode of 1 and the mode of rotation θ _z are coupled, and the compensation calculation circuit in consideration of this is shown.

In the present embodiment, the apparatus and method for performing the compensation calculation of the vibration isolation table vibration in the vibration isolation table vibration control loop has been described for each motion mode. The vibration isolation table vibration compensation calculation is shown in FIG. As described above, it may be performed for each active vibration isolation mount.

Although not described in this embodiment,
A control loop provided with a displacement detecting means for detecting a displacement amount of the vibration isolation table 1 with respect to a reference position, and compensating an output signal of the displacement detecting means to feed back to an actuator incorporated in the active vibration isolation mounts 2a, 2b, 2c, 2d. May be provided. In this case, the means for compensating for the output of the displacement detecting means is based on the displacement signals detected by the plurality of displacement detecting means with respect to the reference position of the vibration isolation table 1 and the displacement signals for each motion mode such as translation and rotation of the vibration isolation table 1. Is extracted, the signal is appropriately compensated, and the compensation signal of each motion mode obtained thereby is distributed to the drive circuits 11a, 11b, 11c, 11d, and incorporated in the active vibration isolation mounts 2a, 2b, 2c, 2d. It may be one that controls a separate actuator.

As described above, the active vibration isolator detects the vibration of the equipment installation foundation by a plurality of vibration detecting means, and from these signals, the vibration signals of each motion mode such as translation and rotation of the equipment installation foundation. The extraction is performed, the compensation is appropriately performed, and the compensation signals of the respective motion modes obtained thereby are distributed to the actuators that apply the control force to the vibration isolation table to perform the control. As a result, in addition to translational vibration of the equipment installation foundation, it is possible to significantly improve the insulation performance of rotational vibration of the equipment installation foundation, which was difficult to secure sufficiently with conventional equipment of this type. It can be suitably used as an anti-vibration table on which a precision instrument that dislikes vibration is mounted.

[Second Embodiment] The second embodiment described in the first embodiment.
As the vibration detection means of, in addition to the usual acceleration sensor,
For example, the first vibration detecting means 3a, 3b, 3c and a plurality of displacements arranged close to the first vibration detecting means 3a, 3b, 3c for detecting relative displacement between the apparatus installation foundation 6 and the vibration isolation table 1 The vibration of the equipment installation foundation may be calculated from the signal of the sensor. In this case, the first vibration detecting means 3a, 3b, 3c and the displacement sensor are arranged as close to each other as possible, and the detection axes of both are preferably coincident with each other.

FIG. 7 is a diagram showing the structure of the active vibration isolator according to this embodiment.

The structure and operation of the vibration isolation table vibration compensation loop in this apparatus are exactly the same as those of the first embodiment. Even if the vibration isolation table vibration compensation calculation is performed for each motion mode, each active vibration isolation mount is used. You may do it every time.

Next, the device installation basic vibration compensation loop in this device will be described.

In this equipment installation foundation vibration compensating loop, the vibration of the equipment installation foundation 6 such as the floor on which the active vibration isolator is installed is determined by, for example, the first vibration detection means 3a, 3b, 3c and the vibration isolation table 1. Displacement sensor 1 that detects the amount of displacement from the position
It is calculated from the output signals of 3a, 13b, and 13c. The displacement sensors 13a, 13b, 13c detect relative displacement between the apparatus installation foundation 6 and the vibration isolation table 1. The displacement sensors 13a, 13b, 13c are the first vibration detecting means 3
It is arranged as close to a, 3b, and 3c as possible, preferably at a position where both detection axes match.

The basic vibration of the apparatus is detected as follows.

An acceleration sensor is used as the first vibration detecting means 3a, 3b, 3c, and the accelerations α _b1 , α _b2 , α _b3 of each part of the vibration isolation table 1 are detected by the acceleration sensor. On the other hand, by the displacement sensors 13a, 13b, 13c arranged in proximity to the first vibration detecting means 3a, 3b, 3c, the relative displacement x ₁ between the device installation base 6 and the vibration isolation table 1 at each part of the vibration isolation table ₁ , x
₂ and x ₃ are detected. Here, the displacement sensors 13a, 13
The outputs x ₁ , x ₂ , x ₃ of b, 13c are the displacement amounts x _b1 , x _b2 , x _{b3 of} each part of the vibration isolation table 1 on the absolute coordinate system and the displacement of the equipment installation foundation 6 on the absolute coordinate system. It is the difference between the quantities x _f1 , x _f2 and x _f3 . Therefore, the signal that is the second-order derivative of that signal is
It is the difference signal between the accelerations α _b1 , α _b2 , α _{b3 of} each part of the vibration isolation table 1 and the accelerations α _f1 , α _f2 , α _f3 of the equipment installation base 6 at the positions where the displacement sensors 13a, 13b, 13c are arranged. .

Therefore, the device installation basic vibration deriving means 14
In a, 14b, and 14c, the first vibration detection means 3
a, 3b, 3c and the displacement sensors 13a, 13b, 13c, the detection gains and their geometrical arrangements are taken into consideration, and the physical quantities of both signals are made to coincide with the acceleration, and the difference signal is derived. Vibration acceleration of α _f1 , α _f2 , α _f3
The signal corresponding to can be extracted. At this time, the first
Vibration detection means 3a, 3b, 3c and displacement sensor 13a,
If the detection axes of the sensors arranged close to each other among 13b and 13c are made to coincide with each other, it is not necessary to consider the geometrical arrangement relationship between them, and the device installation foundation 6 can be calculated by a simpler calculation.
Vibration can be detected.

Therefore, the device installation basic vibration deriving means 14
In a, 14b, and 14c, based on the vibration signal of the device installation foundation 6 derived as described above, each motion mode such as translation and rotation of the device installation foundation 6 in the device installation foundation vibration motion mode extraction circuit 8 The vibration signal is extracted, and the device installation foundation vibration compensation circuit 9 performs appropriate compensation calculation processing on the vibration signal of each motion mode of the device installation foundation 6, and this is applied to the thrust distribution circuit 10 by the drive circuits 11a, 11b. 1
1c, 11d, active isolation mounts 2a, 2b,
By controlling the actuators incorporated in 2c and 2d, an active vibration isolator having the same performance as that of the first embodiment can be realized.

Although not shown in FIG. 7, the displacement sensors 13a, 13b and 13c can also be used for controlling the displacement amount of the vibration isolation table 1 with respect to the reference position.

Further, in the present embodiment, the apparatus installation basic vibration deriving means 14a, 14b, 14c and the apparatus installation basic vibration motion mode extraction circuit 8 are all arithmetic processing means, but these arithmetic processings are performed by one arithmetic processing means. You may do it all at once.

As a result, not only the translational vibration of the equipment installation foundation but also the transmission of rotational vibration to the vibration isolation table can be significantly suppressed, and expensive vibration such as an acceleration sensor as the second vibration detecting means can be suppressed. Since it is not necessary to use the detection means, it is possible to contribute to cost reduction of the device.

[Third Embodiment] In the second embodiment, as the second vibration detecting means for detecting the vibration of the apparatus installation foundation 6, the first vibration detecting means 3a, 3b, 3c and the first vibration detecting means 3a are used. 3b, 3c, which are arranged close to each other, and which derive the signal of the apparatus installation foundation vibration by calculation from the signals of a plurality of displacement sensors that detect the relative displacement of the apparatus installation foundation 6 and the vibration isolation table 1. , Active vibration isolation mounts 2a, 2
When an electromagnetically driven actuator such as a voice coil motor is used for the actuators incorporated in b, 2c, and 2d, the back electromotive force signal of the electromagnetically driven actuator is used to detect the vibration signal of the device installation foundation 6 in a similar manner. Can be detected.

In this case, since the back electromotive force signal of the electromagnetic actuator is proportional to the relative speed of the vibration isolation table 1 and the apparatus installation base 6 at the position of each active vibration isolation mount, the signal is differentiated to accelerate the physical quantity. When the difference signals of the actuators installed in the respective active vibration isolation mounts and the first vibration detection means 3a, 3b, 3c are extracted in consideration of the geometrical arrangement relationship and the like, the apparatus is installed. The vibration acceleration signal of the foundation 6 can be obtained.

The arithmetic processing other than this is the same as in the first embodiment.
And it may be performed in the same manner as that described in the second embodiment.

[0067]

According to the present invention, the vibration of the equipment installation foundation is detected, the signals of the translational and rotational motion modes are extracted from the detected signal, the signals of the respective motion modes are compensated, and Since the control force is applied to the vibration isolation table based on the signal to which the compensation signal is distributed to perform vibration isolation, translational vibration of the equipment installation foundation as well as conventional active vibration isolation technology of this type can be sufficiently secured. It has been possible to significantly improve the insulation performance of the rotary vibration of the equipment installation foundation, which was difficult, and to reduce the vibration transmissibility from the equipment installation foundation to the vibration isolation table to 0 db or less in a very wide frequency band, especially yawing, It can be suitably used for vibration isolation when mounting precision equipment such as pitching and rolling that dislikes rotational vibration.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an active vibration isolator that best represents the features of the present invention.

2 is a diagram showing an arrangement of sensors that detect vibration of a vibration isolation table that can be applied to the apparatus of FIG.

FIG. 3 is a diagram showing an arrangement of sensors for detecting a device installation fundamental vibration that can be applied to the device of FIG.

FIG. 4 is a diagram showing an active vibration isolation mount applicable to the apparatus of FIG. 1 and an arrangement of actuators incorporated therein.

FIG. 5 is a diagram illustrating a compensator having motion mode interference terms that can be applied to the apparatus of FIG. 1;

FIG. 6 is a diagram showing a modified example of the apparatus of FIG.

FIG. 7 is a diagram showing an active vibration isolation device according to a second embodiment of the present invention.

[Explanation of symbols]

1: Vibration isolation table, 2a, 2b, 2c, 2d: Active vibration isolation mount, 3a, 3b, 3c: First vibration detection means, 4: Vibration isolation table vibration motion mode extraction circuit, 5: Vibration isolation table vibration compensation circuit,
6: device installation foundation, 7a, 7b, 7c: second vibration detecting means, 8: device installation foundation vibration motion mode extraction circuit, 9:
Equipment installation basic vibration compensation circuit, 10: Thrust distribution circuit, 11
a, 11b, 11c, 11d: drive circuits, 12a, 12
b, 12c, 12d: actuators, 13a, 13
b, 13c: displacement sensor, 14a, 14b, 14c: device installation basic vibration deriving means.

Continuation of the front page (56) Reference JP-A-7-317835 (JP, A) JP-A-7-310779 (JP, A) JP-A-7-139582 (JP, A) JP-A-6-294445 (JP , A) JP-A-5-99271 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/027 F16F 15/00 G12B 5/00 H01L 21/68 G03F 7/20

Claims (13)

(57) [Claims] 1. A vibration isolating table and, before a plurality of actuators applying force to Kijo isolation table, before a plurality of first vibration system comprises detecting the vibration of the foundation that has been installed Kijo vibration table Based on output signals of the detection means and the plurality of first vibration detection means
Te, extracts a vibration signal of the rotational movement mode of the base, before
An active vibration isolation device, comprising: a control unit that controls the plurality of actuators based on a vibration signal in the rotational motion mode . 2. The control means controls the plurality of vibration detecting hands.
Based on the output signal of the stage, the rotary motion mode of the foundation is determined.
The vibration signal of each motion mode including is extracted, and each motion mode is extracted.
Control the actuators based on the vibration signal
The active vibration isolation device according to claim 1, wherein the active vibration isolation device is controlled. 3. A plurality of second detecting means for detecting vibration of the vibration isolation table.
Together obtain Bei vibration detecting means, said control means further
To, based on an output signal of said plurality of second vibration detection unit
Te, extracts a vibration signal for each motion mode of the anti-vibration table, before
Serial active anti-vibration apparatus according to claim 1 or 2, wherein the one in which the controls a plurality of activator <br/> Yueta based on the vibration signal for each motion mode. 4. A plurality of displacement detection means for detecting a displacement amount of the vibration isolation table with respect to a reference position, wherein the control means is provided.
Luo, active anti-vibration apparatus according to any one of claims 1-3, characterized in that for controlling the pre <br/> SL plurality of actuators based on the output signal of the plurality of displacement detection means. Wherein said control means based on the output signal of the plurality of displacement detection means to extract a displacement signal of the motion mode of the anti-vibration table, based on the displacement signal of the respective motion modes
Active anti-vibration apparatus according to claim 4, characterized in that for controlling the plurality of actuators are. Wherein said plurality of actuators, electric磁駆dynamic
Of Li linear motors and pneumatic control actuator small
At least one is included, The one of Claims 1-6 characterized by the above-mentioned.
The active vibration isolation device according to any one of the above. 7. At least one of the plurality of first vibration detection unit and before <br/> SL plurality of second vibration detecting means, any claim 1-6, characterized in that the acceleration sensor
The active vibration isolator according to any one of the above. 8. A vibration of an anti-vibration table, which is vibration-isolated with respect to the foundation, is detected, the detected signal is compensated, a control force based on the compensation signal is applied to the anti-vibration table, and Vibration is detected, translational and rotational motion mode signals are extracted from this detection signal, each motion mode signal is compensated, and a control force is applied to the vibration isolation table based on the signal obtained by distributing the compensation signal. An active vibration isolation method characterized by the above. 9. A vibration isolator and a plurality of
The vibration of the foundation on which the device, including the actuator, is installed
Based on the output signals of the plurality of first vibration detecting means for detecting movement.
Then, the vibration signal of the rotary motion mode of the foundation is extracted.
Based on the vibration signal of the rotational motion mode,
Vibration isolation characterized by controlling the actuator of the
Method. 10. In the output signal of the plurality of vibration detection means
Based on each motion mode including the rotational motion mode of the foundation,
The vibration signal of the motion
Based on controlling the plurality of actuators based on
The active vibration isolation method according to claim 9, which is used as a characteristic. 11. Furthermore, the vibration of the vibration isolation table is detected.
Based on the output signals of the plurality of second vibration detection means,
Extract the vibration signal of each motion mode of the vibration isolation table,
The plurality of actuators based on modal vibration signals
11. The method according to claim 9 or 10, characterized in that
Active vibration isolation method. 12. The method according to claim 12, Furthermore, the vibration isolation table for the reference position
Based on the output signals of a plurality of displacement detection means for detecting the displacement amount of
Characterized by controlling the plurality of actuators based on
Active vibration isolation according to any one of claims 9 to 11.
Method. 13. The output signals of the plurality of displacement detection means
Extraction of displacement signal of each motion mode of the vibration isolation table based on
Then, based on the displacement signal of each of the motion modes,
13. An actuator is controlled to control the actuator.
Active vibration isolation method described.