KR20080097288A - Active passive vibration isolator using voice coil motor - Google Patents

Abstract

An automatic and manual damper is provided that the displacement is made by using the voice coil motor and it is possible for the low-frequency damping and being lowered at the resonance point. An automatic and manual damper comprises a plurality of manual dampers(15) comprised of the phase consisting of the metal material, and the lower plate, and the elastic body damping the frequency of the high frequency substitution, an automatic damper which is connected in parallel with the manual damper and comprised of one or more voice coil motors(51) damping the frequency of the low side, and acceleration sensors(53a, 53b).

Description

Active passive vibration isolator using voice coil motor

Figure 1 is a schematic diagram showing a state in which the active damper and passive damper in parallel.

2 is a perspective view of a passive vibration damper composed of an elastic body having a metal upper plate and a lower plate;

3 is a graph showing the transfer function of the output p (s) against the external stress Fu (s).

Figure 4 is a graph showing the transfer rate of the output for the floor vibration (b (s)).

Figure 5 is a perspective view showing a state in which the passive vibration damper and active vibration damper according to the present invention in parallel.

Figure 6 is a perspective view showing the configuration of a vertical voice coil motor according to the present invention.

Figure 7 is a perspective view of a vertical voice coil motor with a coil removed in accordance with the present invention.

Figure 8 is a perspective view showing the arrangement of the coil of the vertical voice coil motor according to the present invention.

9 is a perspective view showing the configuration of a horizontal voice coil motor according to the present invention.

10 is a perspective view of a horizontal voice coil motor with a coil removed in accordance with the present invention.

Figure 11 is a perspective view showing the arrangement of the coil of the horizontal voice coil motor according to the present invention.

12 is a block diagram showing the relative position of the voice coil motor and the acceleration sensor according to the present invention.

Figure 13 is a schematic diagram showing the relationship between the force in the z-axis direction of the three vertical voice coil motor according to the present invention.

Figure 14 is a schematic diagram showing the relationship between the force in the horizontal direction of the voice coil motor of the three horizontal direction in accordance with the present invention.

FIG. 15 is a graph showing open loop transfer rate in a coupled bond mode. FIG.

16 is a block diagram showing feedback control of the speed of a load point.

Figure 17 is a graph showing the transfer rate in the state in which the active and passive vibration damper according to the present invention.

<Description of Signs of Major Parts of Drawings>

11: rigid spring,

12: damper,

14: load point,

15: manual vibration damper,

22: elastic body,

51: Vertical voice coil motor,

51a: Magnet of vertical voice coil motor,

51b: York of vertical voice coil motor,

51c: coil of vertical voice coil motor,

51d: coil jig of vertical voice coil motor,

51e: coil support of vertical voice coil motor,

52: horizontal voice coil motor,

52a: Magnet of horizontal voice coil motor,

52b: York of horizontal voice coil motor,

52c: coil of horizontal voice coil motor,

52d: coil cover of horizontal voice coil motor,

52e: coil support of horizontal voice coil motor,

53a: vertical acceleration sensor,

53b: horizontal acceleration sensor,

54: The top plate of the active passive vibration damper,

55: the bottom of the active passive vibration damper,

91;

92: integrator.

The present invention relates to an active passive vibration suppressor using a voice coil motor, and more particularly, a passive vibration suppressor that supports the load of the device and attenuates a high frequency band and is connected in parallel to the resonance damper to reduce the resonance frequency. The present invention relates to an active vibration damper which reduces vibration amplitude and improves vibration damping performance.

In the precision processing and inspection process, the generation of vibration is directly connected to the defective product, so we apply the fine vibration regulation value for each device and process. When constructing the process system, the vibration control system must be designed together from the construction stage. Most of the precision processes used up to now have passive vibration damping method, which is a high frequency vibration damping method that cancels vibration by using a rigid device such as a mount or a damper. However, as the process becomes more precise, the required damping performance also increases, and the passive damping system for achieving improved damping performance is economically and technically limited. Therefore, the active control system showing excellent performance in the vibration control of low frequency components has been applied in the hybrid form in addition to the existing high frequency oriented passive system.

Active vibration control system is divided into actuators according to the applied actuators. Pneumatic and hydraulic are adopted for the vibration of structures requiring large displacements and forces, and micro vibration control such as precision process equipment is applied to electromagnetic and piezo motors. Use an actuator.

Active micro-vibration control technology is a key technology to achieve the ultra-precision precision required by production and inspection facilities of representative high value-added precision industries such as next-generation semiconductors and displays. Particularly, in the Giga-class semiconductor process and next-generation PDP / LCD process requiring processing accuracy of line width 0.1 ~ 0.23㎛, micro vibration from the ground becomes a problem, and high-performance dustproof system is essential to control this.

In the conventional invention, a piezo motor is used to perform such active vibration suppression, and the use of such a piezo motor not only generates a lot of costs, but also has a small displacement and a weak controllable force, thus preventing vibration against a larger external vibration. It is difficult to achieve the disadvantage.

In addition, when piezo motors are connected in series with elastic mounts, this system requires additional floor vibrations compared to parallel, requiring additional sensors, which is expensive. In addition, if the sensor is not additionally installed, it has two degrees of freedom, making it difficult to control. In addition, calibration is necessary because the resonant frequency of the elastic mount changes according to the added load.

The present invention has been made to solve this problem, and has the object of making the displacement large by using a voice coil motor, and achieving a vibration damping effect against large external vibrations by controlling the force.

In addition, it is another object of the present invention to obtain a simple control performance by using the acceleration sensor only for feedback control without installing an additional sensor through a parallel structure.

The active passive vibration suppressor using the voice coil motor according to the present invention includes a plurality of passive components including an upper body and a lower plate composed of metal, and an elastic body interposed in close contact with an intermediate part of the upper and lower plates to damp the high frequency band. A vibration damper; An active vibration damper including a voice coil motor connected to a plurality of passive vibration suppressors in parallel to reduce the frequency of a low frequency band, and an acceleration sensor for transmitting the acceleration of the upper and lower plates of the active passive vibration suppressor to the voice coil motor as a feedback signal. It characterized by consisting of.

This will be described in detail with reference to the accompanying drawings. 1 shows an active passive vibration suppressor seen in one dimension as applied to the present invention. The spring 11 represented by the spring in FIG. 1 is K, the damping 12 is C, and the voice coil motor 13 is connected in parallel with the vibrating bottom F. In FIG. The model above shows that the floor vibration B (s) effectively blocks the transmission of the load point M (14). As shown in Fig. 1, the passive vibration suppressor 15 serves to support the load applied to the load point, and provides sufficient attenuation within its resonance frequency and a range of damping at resonance.

2 shows the structure of the passive vibration damper 15. The metal support 21 of the lower plate fixes the elastic body 22 to the lower plate, and the bolt fastening mechanism 24 has the elastic body 22 between the metal support 23 of the upper plate and the metal support 21 of the lower plate interposed therebetween. . The elastic body 22 serves to provide rigidity and damping to the active passive vibration suppressor.

In detail, the effect of the system model having the floor vibration signal input b (s) and the control signal input Fu (s) on the output variable p (s) is as follows.

In this case, the equations for the four mounts are as follows.

F _x = M _p X _p "+ C _x (X _P '-X _B ') + K _x (X _p -X _B ) + C _x P _z (θ _yp '-θ _yB ' ) + K _x P _z (θ _yp -θ _yB )

F _Y = M _P Y _p "+ C _y (Y _P '-Y _B ') + K _y (Y _P -Y _B ) -C _y P _z (θ _xp '-θ _xb ') -K _y P _z ( θ _xp -θ _xb )

M _θz = I _zz θ " _zp + (C _x P _y ² + C _y P _x ² ) (θ _zp '-θ _zb ') + (K _x P _y ² + K _y P _x ² ) (θ _zp -θ _zb )

F _Z = M _P Z _p "+ C _z (Z ' _p -Z' _B ) + K _z (Z _p -Z _B )

M _θx = I _xx θ " _xp -C _x P _z (Y _P '-Y _B ') -K _y P _z (Y _p -Y _B ) + (C _y P _z ² ) (θ _xp '-θ _xb ' )

+ (K _y P _z ² ) (θ _xp -θ _xb )

M _θy = I _yy θ " _yp + C _x P _z (X _P '-X _B ') + K _x P _z (X _p -X _B ) + (C _x P _z ² ) (θ _yp '-θ _yb ' )

+ (C _x P _z ² ) (θ _yp -θ _yb )

Where M _P represents the mass at the load point, C _x represents damping about the major axis and K _x represents rigidity about the major axis. P _x , P _{y and} P _z also represent relative distances from the center of mass of the mounted equipment. If the following equation is expressed in matrix form, it is as follows.

As is apparent from the matrix, Equations 3 and 4 are not combined, and other equations are combined. In this case, the influence of the control signal input Fu (s) and the bottom vibration input b (s) on the output variable P (s) can be expressed by the following equation.

([M] s ² + [C] s + [K]) p (s) = [C] sb (s) + [K] b (s) + Fu (s)

⇒p (s) =

P (s) = Gc (s) Fu (s) + G _T (s) b (s)

M, C, K are mass, damping and stiffness matrix, Gc (s) is the transfer function for the input of the control signal Fu (s), and G _T (s) represents the transfer rate of the floor vibration b (s), respectively. .

3 and 4 show the transfer function for the input of the control signal and the transfer rate for the input of the floor vibration, respectively. From this, it can be seen that the output p (s) for Fu (s) and the output p (s) for floor vibration b (s) are combined.

An active vibration suppressor is used for the vibration isolation of the low frequency band, which is applied to the voice coil motors 51 in three vertical directions, the voice coil motors 52 in three horizontal directions, and the voice coil motors 51 and 52. Acceleration sensors 53a and 53b for transmitting the acceleration of the active passive vibration suppressor as a feedback signal are included. Voice coil motors (51, 52) can be said to be a kind of actuator, the actuator is driven by Fleming's left hand law. That is, the force generated by the interaction between the current moving through the coil and the permanent magnetic field is transmitted to the upper plate 54 of the active passive vibration suppressor, and the current flows by the force transmitted to the upper plate 54 of the active passive vibration suppressor. The coil is supposed to move.

5 is a perspective view showing the arrangement of an active passive vibration suppressor according to the present invention in which four passive vibration dampers and six voice coil motors 51 and acceleration sensors 53a and 53b in the vertical direction and the vertical direction are combined. Four passive vibration dampers, six voice coil motors 51 and six acceleration sensors 53a and 53b are positioned below the upper plate 54. The four passive vibration dampers 15 below the upper plate 54 have upper and lower surfaces 23 and 21 made of metal as described above, and are composed of an elastic body 22 interposed between the upper and lower surfaces 21 and 230. The active vibration damper connected in parallel includes six voice coil motors 51 and 52, three horizontal acceleration sensors 53b, and three vertical acceleration sensors 53a. The three vertical voice coil motors 51 and 52 are disposed at each vertex position of the equilateral triangle to balance the vertical force, and the three horizontal voice coil motors 52 are provided. They are placed at the vertices of the equilateral triangles to balance the forces in the x- and y-axis directions, and the acceleration sensors 53a and 53b are the acceleration sensor 53a in the vertical direction and the acceleration sensor 53b in the horizontal direction. Room with load point M (14) And the role of providing the absolute value of the acceleration.

The vertical voice coil motor 51 and the horizontal voice coil motor 52 are designed by this principle.

The operation thereof will be described in detail with reference to FIGS. 6 to 11.

6 is a detailed view showing the vertical voice coil motor 51. In order to describe the vertical voice coil motor 51 in detail, the description will be made as shown in FIGS. 7 and 8. 7 shows the vertical voice coil motor 51 with the coil 51c removed. The magnet 51a is attached to the yoke 51b on the side of the voice coil motor 51 so that the magnet 51a is perpendicular to the direction of the current, thereby transmitting the driving force in the vertical direction by the Lorentz force. FIG. 8 is a perspective view showing an assembly of coils 51c coupled together to a vertical voice coil motor 51 without the coil 51b of FIG.

As shown in FIG. 8, the coil 51c is located under the jig 51d of the coil while the current flows.

To find the equation for this force, we will use a model with one degree of freedom for the force acting in the z-axis direction. here

K _z = 4 * K _dyn = 8.6 * 10 ⁵ N / m and C _z = 4 * C _dyn = 1.42 * 10 ³ Ns / m

Let's use the model. At this time, the force required for the vertical voice coil motor 51 becomes as shown in [Equation 9].

Ms ² P (s) + Cs (P (s) -B (s)) + K (P (s) -B (s)) = Ft = 3F _VCM = 3nBgli = 3K _t i

⇒ Ms ² T (s) B (s) + CsB (s) (T (s) -1) + KB (s) (T (s) -1) = 3F _VCM

Where T (s) is the transmission rate of the passive vibration suppressor, Kt is the constant of the force, n is the number of revolutions of the coil, Bg is the magnetic flux density between the air layers, and l is the effective length of the coil.

In order to find the maximum force required for the bandwidth of 0.1 to 100 Hz, consider 100 Hz, where the maximum acceleration and speed are transmitted to the top plate in the passive vibration damper. If we calculate the transfer rate, T (s) = 0.0143 = -36.9 dB. It is shown in FIG. 4 that the transmission rate of the passive damper varies with frequency.

At this time, the maximum force to be obtained is shown in Equation 10 below.

3F _VCM = MTs ² B (s) + CsB (s) (T-1) + KB (s) (T-1) ⇒ F _VCM = -29.33N

(At this time, assume that K = 8.6 * 10 ⁵ (N / m) and C = 1420 (Ns / m) of the manual vibration damper.)

9 is a detailed view showing the structure of the horizontal voice coil motor 52. 10 and 11 show the state of the horizontal voice coil motor 52 with the coil 52c removed and the coil 52c disposed. FIG. 10 shows the voice coil motor 52 with the coil removed, and unlike the vertical voice coil motor 51, the magnet 52a is attached to the lower surface of the yoke 52b and the coil 52c shown in FIG. In a vertical state, the movement of the load point 14 in the x and y axis directions is controlled. As described above, this force is also driven by Fleming's left-hand law to give the Lorentz force.

If the voice coil motors 51 and 52 and the acceleration sensors 53a and 53b are designed according to the requirements thereof, the arrangement is as shown in FIG. 12. All the voice coil motors 51 and 52 are connected to the upper plate 54. As described above, the voice coil motors 51 and 52 form a structure disposed at the vertex position of the equilateral triangle.

The equations for the forces generated by the three vertical voice coil motors 51 are represented by Equations 11 to 13. (Where Lv represents the height of the equilateral triangle, L _H represents the length of one side of the equilateral triangle. Fz is the force in the z direction, and M _θx and M _θy represent the moments.)

Fz = F1 + F2 + F3

M _θx = (F1 + F2) (L _V / 3) -F3 * (2L _V / 3)

M _θy = F2 * (L _H / 2)-F1 * (L _H / 2)

Similarly, the equation for the force generated by the three horizontal voice coil motor 52 is as follows. (F _x and F _y are the forces in the x and y directions, and M _θZ are the moments.)

Fx = Fa-Fb cos (π / 3) -Fc cos (π / 3)

Fy = 0 * Fa + Fb sin (π / 3) -Fc sin (π / 3)

_{M θz = L V cosθz (Fa} + Fb + Fc)

13 and 14 show the relationship between the vertical force and the horizontal force, respectively.

The sensor 53 is mounted on the voice coil motors 51 and 52 to check the disturbance transmitted through the passive vibration damper and provide a feedback signal to the voice coil motors 51 and 52.

From the acceleration sensors 53a and 53b, six modes of translation elements Xm, Ym and Zm and rotation elements θ _zm , θ _xm and θ _ym can be measured.

W and Ls represent relative dimensions.

Here, six horizontal and vertical acceleration sensors 53a and 53b are used, which are suitable for detecting very low amplitude vibrations.

The above is described with respect to the three vertical voice coil motor 51 and the horizontal voice coil motor 52, but a plurality of vertical voice coil motor 51 and a plurality of in order to adjust the force in the six-axis direction The two horizontal voice coil motors 52 can also be applied to the analogical analogy in view of those skilled in the art and can be omitted.

This minimizes the resonant frequency and reduces the amplitude at resonance by using the passive vibration damper 15 having four mounts, the voice coil motors 51 and 52, and the acceleration sensors 53a and 53b. It is possible to design a damper that can be reduced.

16 combines the compensator 91 and the integrator 92 to calculate a signal for the speed sP (s) of the load point M (14) as a controlled stress Fu (s) to load point M (14). Is a block diagram showing the process of transmitting the signal of acceleration of) as a feedback signal.

The compensator 91 is used for Proportional-Integral-Derivative control. The first consideration in the design of this compensator 91 is the vibration isolation and the stability of the closed circuit against disturbance of the floor vibration b (s).

In addition, a single input single output (SISO) model has been designed that uses modal decomposition to isolate six rigid body-mode vibrations and to use a feedback compensator 91 for the individual modes to be controlled.

15 shows open mode transfer rates in isolated mode. As shown in FIG. 15, since the bottom vibration is not coupled, individual control is possible.

16 shows a block diagram for a speed feedback control system.

Where Mm, Cm and Km represent modal mass, damping matrix and stiffness matrix. When the feedback velocity signal sP (s) is input, the feedback stress Fu (s) is

Fu (s) = K ₁ P (s) + K _p sP (s) + K _D s ² P (s) is obtained. Where K _I is the integrated signal gain, K _p is the proportional signal gain, and K _D is the differential signal gain.

 The closed loop transfer function for the floor vibration from the load point 14 is

The purpose of the system is to achieve a low resonance frequency (f _CL = 0.1 Hz) and a high damping ratio (ξ _CL > = 1.0). The combined open loop transfer rate and closed loop transfer rate after tuning using proportional derivatives are shown in FIG. 17. As can be seen from FIG. 17, it can be seen that closed loop proportional integral compensation (PID) not only provides sufficient active damping, but also achieves a vibration isolation effect with a low cutoff frequency of up to 0.1 Hz.

By connecting the passive vibration damper and the active vibration damper in parallel, it is possible not only to enable vibration suppression of low frequency below 100 Hz, but also to obtain the effect of lowering the amplitude at the resonance point. In addition, in case of series connection, attenuation rate of higher vibration can be obtained. However, in the case of parallel connection, it becomes 1 degree of freedom, which makes it easy to control.

In the case of using an active vibration damper using the voice coil motor 51 according to the present invention, the vibration damping effect can be obtained against external vibrations having a larger displacement and greater force than the conventional vibration damper using a piezo motor and an elastic mount. . In addition, the combination of the active vibration damper and the passive vibration damper enables not only low frequency vibration damping but also lowering the amplitude at the resonance point.

Claims (8)

A plurality of passives including an upper and lower plates 21 and 23 made of a metal material and an elastic body 22 which is interposed close to the middle part of the upper and lower plates 21 and 23 to damp the frequency of the high frequency band. A vibration damper 15; One or more voice coil motors 51 which are connected in parallel with the passive vibration suppressor to damp the frequencies of the low frequency band, and an acceleration sensor 53a for transmitting the acceleration of the upper and lower plates 54 and 55 of the active passive vibration suppressor as feedback signals. Active vibration damper, comprising; 53b). The method of claim 1, The voice coil motor (51, 52) is an active passive vibration suppressor using a plurality of vertical voice coil motor (51) and a plurality of horizontal voice coil motor (52) to adjust the displacement of the six axes. The method of claim 2, The plurality of vertical voice coil motors 51 is an active passive vibration suppressor using a voice coil motor 51 disposed at each vertex of an equilateral triangle or each vertex position of a square. The method of claim 3, wherein The plurality of voice coil motors 51 in the vertical direction have a magnet 51a attached to a side of the yoke 51b, and a coil 51c is disposed in a direction perpendicular thereto so that the coil can be moved in the z-axis direction. Active passive vibration suppressor using the voice coil motor 51, characterized in that. The method of claim 2, The plurality of horizontal voice coil motors 52 is an active passive vibration suppressor using a voice coil motor 52 disposed at each vertex of an equilateral triangle or each vertex position of a square. The method of claim 5, The plurality of horizontal voice coil motors 52 have magnets 52b attached to upper and lower surfaces of the yoke 52b, and coils 52c are disposed in a direction perpendicular thereto to move the coils in the x and y axis directions. Active passive vibration suppressor using the voice coil motor 52, characterized in that to enable. The method of claim 1, The acceleration sensors 53a and 53b are positioned on the same plane as the voice coil motors 51 and 52 to measure the vertical acceleration and the vertical acceleration of the load point M 14. Active Passive Vibrators using 51,52). The method of claim 1, The control method for measuring the absolute acceleration of the load point 14 to the voice coil motors 51 and 52 and transmitting the speed feedback signal is a proportional differential integral control method. Active passive vibration damper used.

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