JPH10143254A - Active damping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To independently control an object for control, to be damped with high performance in three degree of-freedoms in the horizontal direction while decreasing the number of sensors and actuators as much as possible. SOLUTION: This device has horizontal vibration sensors 1', 2', 3' and 4' and horizontal displacement sensors 1'', 2'', 3'' and 4'' for detecting the horizontal vibration and displacement of a controlled system 9 to be de-excited as well as plural horizontal actuators 1, 2, 3 and 4 for injecting a horizontal manipulated variable (u) through a control system 10 based on detected amounts from the horizontal vibration sensors and the horizontal displacement sensors. The respective sensors and actuators are respectively practically positioned at four corners A, B, C and D and the detecting direction of respective sensors and the manipulated variable generating direction of actuators are provided point- symmetrically while being orthogonal with a straight line L connecting the center point O in the horizontal direction of the controlled system with four corners.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active vibration isolator and, more particularly, to an active vibration isolator which effectively works on complicated vibrations caused by self-excitation or the like.

[0002]

2. Description of the Related Art Conventionally, in order to obtain the precision required for precision equipment represented by a semiconductor manufacturing / inspection apparatus, an electron microscope, an optical measuring instrument, etc.
An active anti-vibration device that supports these facilities from vibrations from the installation foundation or floor is used. As shown in FIG. 3, for example, as shown in FIG. 3, such an active anti-vibration device is provided with + x and -x horizontal directions to vibrate the horizontal vibration of a control object 55 such as a surface plate on which precision equipment and the like are mounted. A horizontal actuator 51 having manipulated variables u51, u52,
52, and horizontal actuators 53 and 54 having + y and -y horizontal operation amounts u53 and u54 are provided near the midpoint of each side of the control target 55, respectively. Therefore, the operation amount ux in the x horizontal direction by the horizontal actuators 51 and 52 is

[0003]

(Equation 2)

The horizontal actuators 53, 5
The operation amount uy in the y-horizontal direction according to 4 is

[0005]

(Equation 3)

[0006] In order to detect horizontal vibration, horizontal actuators 51, 52, 53, 5
The same number of horizontal sensors (not shown) as 4 are controlled objects 5
5 is installed. However, in the active vibration isolator 50, the operation amount uω in the yawing horizontal direction is
Could not be injected, and had only two degrees of freedom in the horizontal direction. Further, the horizontal actuators 51, 52, 53, near the midpoint of each side of the control target 55,
Since the 54 is provided, there is a possibility that it interferes with the load and its wiring and piping.

In a six-degree-of-freedom vibration system, in order to control each vibration independently, a number of sensors and actuators corresponding to each vibration are required. SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem. An active vibration isolator capable of independently controlling the three degrees of freedom with high performance by reducing the number of sensors and actuators as much as possible. The purpose is to provide.

[0008]

An active vibration isolator according to the present invention for achieving the above object comprises a plurality of horizontal sensors for detecting horizontal vibration or displacement of a controlled object to be removed, and A plurality of horizontal actuators for injecting a horizontal operation amount via a control system based on a detection amount from the direction sensor, wherein the plurality of horizontal sensors and the plurality of horizontal actuators are substantially controlled objects respectively. The detection direction of the horizontal sensor and the operation amount generation direction of the horizontal actuator located at the four corners of the object are point-symmetrical at right angles to a straight line connecting the horizontal center point of the controlled object and the four corners. It is provided as follows.

In the active vibration isolator according to the present invention, when the control system is at a predetermined angle with respect to the horizontal long axis in the detection direction of the horizontal sensor and the operation amount generation direction of the horizontal actuator, the control system calculates the operation force from the detected amount. Calculate the variable and calculate the determinant from the manipulated variable.

[0010]

(Equation 4)

And a calculating means for calculating the operation amount of the horizontal actuator.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an active vibration isolator according to the present invention will be described below with reference to the drawings. This active vibration isolator includes a vibration-isolated table or a control object 9 (see FIG. 1 (FIG. a)) is provided.

As shown in FIGS. 1 (a) and 2, the control object 9 has horizontal vibration sensors 1 ', 2', 3 ', 4 which detect vibration and output a horizontal vibration signal S1. 'Is mounted. These horizontal vibration sensors 1 ', 2',
3 'and 4' are substantially four corners A of the control object 9, respectively.
B, C, D, the acceleration or speed detection direction is the horizontal center point O and four corners A, B, C,
It is mounted so as to be point-symmetrical at right angles to a straight line L connecting D and D.

These horizontal vibration sensors 1 ', 2',
As the 3 'and 4', for example, a known acceleration sensor, speed sensor, gyro, or the like can be used. When a speed sensor is used as the horizontal vibration sensor, the acceleration signal is obtained by differentiating the speed once. When an acceleration sensor is used as the horizontal vibration sensor, the speed signal is obtained by integrating the acceleration once. Here, the controlled object 9 includes not only a vibration-isolated table such as a surface plate, but also precision equipment such as an electron microscope mounted on the table and a stepper which is an IC and LSI manufacturing apparatus. In this case, the horizontal vibration sensors 1 ', 2', 3 ', 4' may be mounted on such precision equipment itself.

A non-contact horizontal displacement sensor 1 ", 2", 3 ", 4" for detecting a horizontal displacement of the control object 9 and outputting a horizontal displacement signal S10 is provided by the control object 9 or 9 ". It is mounted on any of the installation surfaces. The non-contact horizontal displacement sensors 1 ", 2", 3 ", 4" are substantially the four corners A of the control object 9 similarly to the above-described horizontal vibration sensors 1 ', 2', 3 ', 4'. , B, C, D,
The position detection directions of the non-contact horizontal displacement sensors 1 ", 2", 3 ", and 4" correspond to a straight line L connecting the horizontal center point O of the control object 9 and the four corners A, B, C, and D. On the other hand, it is mounted so as to be orthogonal and point symmetric. As the non-contact horizontal displacement sensors 1 ", 2", 3 ", 4", for example, an eddy current element, a differential transformer, a potentiometer, an LED, a laser element or the like can be adopted.

Further, horizontal vibration sensors 1 ', 2',
3 ', 4' and non-contact horizontal displacement sensor 1 ",
Vibration signal S1 and displacement signal S1 from 2 ", 3", 4 "
Horizontal actuators 1, 2, 3, and 4 driven by a control system 10 through 0 are provided for the control target 9. This horizontal actuator 1, 2, 3, 4
Similarly to the horizontal vibration sensors 1 ', 2', 3 ', 4' and the non-contact horizontal displacement sensors 1 ", 2", 3 ", 4", the four corners A of the control object 9 are substantially each. B, C, D
, And the operating force generation direction of the horizontal actuators 1, 2, 3, 4 is orthogonal to a straight line L connecting the horizontal center point O of the control object 9 and the four corners A, B, C, D. It is mounted so as to be point symmetric. As the horizontal actuators 1, 2, 3, and 4, for example, an air spring,
A VCM (voice coil motor), a piezo element, or the like can be used.

Such a horizontal vibration sensor 1 ',
2 ′, 3 ′, 4 ′, non-contact horizontal displacement sensor 1 ″,
2 ", 3", 4 "and horizontal actuator 1,
In the active vibration isolator provided with 2, 3, and 4, for example, in order to control the control object 9 in the x direction with the operation force variable ux, the horizontal actuator 1

[0018]

(Equation 5)

In the horizontal actuator 2,

[0020]

(Equation 6)

In the horizontal actuator 3,

[0022]

(Equation 7)

In the horizontal actuator 4,

[0024]

(Equation 8)

The following manipulated variables are generated. In addition,
θ is the amount of deviation (angle) of the operation force generation direction of the horizontal actuators 1, 2, 3, 4 with respect to the horizontal long axis x.
However, 0 ° <θ <π / 2. In addition, the control object 9
Is controlled in the y direction by the operation force variable uy.

[0026]

(Equation 9)

The horizontal actuator 2

[0028]

(Equation 10)

The horizontal actuator 3

[0030]

[Equation 11]

The horizontal actuator 4

[0032]

(Equation 12)

The following operation amounts are generated. Further, the operation force variable uω is set in the rotation direction of the vertical axis of the control object 9.
In order to control by the horizontal actuator 1,

[0034]

(Equation 13)

In the horizontal actuator 2,

[0036]

[Equation 14]

The horizontal actuator 3

[0038]

(Equation 15)

The horizontal actuator 4

[0040]

(Equation 16)

The following operation amounts are generated. Each operation amount u of these horizontal actuators 1, 2, 3, 4
The relationship between 1, u2, u3, u4 and the operation force variables ux, uy, uω can be summarized as a determinant.

[0042]

[Equation 17]

And u = H · u ′ ‥‥‥ (16). Here, u is an operation amount, H is a transformation matrix, and u ′ is an operation force variable. Therefore, the horizontal actuator 1 is in the direction of arrow E, the horizontal actuator 2 is in the direction of arrow F, and the horizontal actuator 3 is in the direction of arrow G.
Since the directional and horizontal actuators 4 can respectively generate the operation amounts in the direction of the arrow H, the balance of the forces can be maintained. Accordingly, a force in the pulling direction can be generated, and thus control of the control object 9 in the rotation direction of the vertical axis becomes possible.

The horizontal vibration sensors 1 ', 2',
3 ', 4' or non-contact horizontal displacement sensor 1 ",
To calculate the operation force variables ux, uy, uω from the acceleration (or speed) or displacement detected by 2 ″, 3 ″, 4 ″, classical control such as PI control, H∞ control, optimal control, etc. Modern control is used, such a conversion matrix and control rules are executed by a control system 10 as shown in Fig. 1 (b), that is, the horizontal vibration sensor 1 'mounted on the control object 9. Detected at 2 ', 3', 4 ',
For example, the acceleration detection amount is converted into acceleration. An operation force variable u '= ux using, for example, H∞ control for this acceleration,
Calculate uy and uω. The operation force variable u ′ obtained by the H∞ control is inversely transformed by a transformation matrix H, and the operation amount u =
u1, u2, u3, and u4 are obtained and used as control signals S3 for canceling vibrations and the like by the horizontal actuators 1, 2, 3, and 4. In addition, a non-contact horizontal displacement sensor 1 ″,
The operation amounts u = u1, u2, u3, and u4 are obtained by calculating the displacement detection amounts detected at 2 ", 3", and 4 "in the same manner, and the vibrations by the horizontal actuators 1, 2, 3, and 4, etc. Is used as a control signal S3 for canceling the above.A microcomputer, a personal computer, or the like is used as arithmetic means of such a control system 10.

As a result, the control object 11 controlled by the control system 10 can be independently controlled with high performance in three degrees of freedom of horizontal components (x, y, ω). The control object 11 controlled by the control system 10 is not limited to the control object 9 defined in the present embodiment, but includes the horizontal actuators 1, 2, 3, and 4.

[0046]

As described above, according to the active anti-vibration apparatus of the present invention, the three degrees of freedom in the horizontal direction can be controlled at a high performance with a small number of sensors and actuators. Space and a good vibration isolation device can be realized. In addition, since it can be separated into each degree of freedom and can be controlled independently, it is easy to adjust, and the vibration isolation performance can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of an active vibration isolator according to the present invention, in which (a) is an explanatory diagram and (b) is a block diagram of a control system.

FIG. 2 is a block diagram showing an embodiment of the active vibration isolation device of the present invention.

FIG. 3 is an explanatory diagram of a conventional active vibration isolation device.

[Explanation of symbols]

1, 2, 3, 4 ... horizontal actuator 1 ', 2', 3 ', 4' ... horizontal vibration sensor 1 ", 2", 3 ", 4" ... non-contact horizontal displacement sensor 10 ... control system 9 ... Control objects A, B, C, D ... Four corners of the control object O ... Horizontal center point of the control object L ... Straight line connecting the horizontal center point of the control object and the four corners θ ... Predetermined angles ux, uy, uω ... operation force variables u1, u2, u3, u4 ... operation amounts

Claims (2)

[Claims] A plurality of horizontal sensors (1 ', 2', 3 ', 4', 1 ", 2", 3 ") for detecting horizontal vibration or displacement of a control object (9) to be vibrated. "4")
And operation amounts (u1, u2, u3, u3,...) In the horizontal direction through the control system (10) based on the detection amount from the horizontal direction sensor.
u4) to inject a plurality of horizontal actuators (1,
2, 3, 4), wherein the plurality of horizontal sensors and the plurality of horizontal actuators are respectively located substantially at four corners (A, B, C, D) of the control object, and The detection direction of the horizontal sensor and the operation amount generation direction of the horizontal actuator are point-symmetrical at right angles to a straight line (L) connecting the horizontal center point (O) of the controlled object and the four corners. An active vibration isolator, which is provided to be: 2. The control system according to claim 1, wherein a predetermined angle (θ) is set with respect to a horizontal long axis (x) in a detection direction of the horizontal sensor and an operation amount generation direction of the horizontal actuator.
An operation force variable (ux, uy, uω) is calculated from the detected amount, and a determinant is calculated from the operation force variable. 2. The active vibration isolator according to claim 1, further comprising a calculation unit that calculates the operation amount of the horizontal actuator by using the operation unit.