Vibration treatment device, stage drive device, vibration treatment method, vibration treatment program

Abstract

To provide a vibration processor making it possible to further upgrade the precision of an actuator.SOLUTION: A vibration processor 3 includes an X actuator 120, a vibration data collection unit 31 that collects vibration data when a Y actuator 130 is not driven, a peak frequency identification unit 32 that identifies at least one of peak frequencies, at which a maximal value appears, through frequency analysis of vibration data, a peak frequency output unit 33 that outputs a peak frequency, and an object-of-suppression frequency designation unit 35 that designates as an object-of-suppression frequency a peak frequency, which is outputted by the peak frequency output unit 33, for a filter 4 capable of suppressing a frequency component of a predetermined object-of-suppression frequency when the X actuator 120 and Y actuator 130 are not driven.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to vibration processing for actuators. [Background Art]

[0002] Patent Document 1 discloses a stage driving device for an exposure apparatus used in semiconductor manufacturing, which is capable of automatically removing resonance frequency components during stage driving. Resonance associated with stage driving is detected through signal analysis when the stage is driven to a target position, and the frequency characteristics of the filter are automatically adjusted to remove the frequency component. [Prior Art Literature] [Patent Literature]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2003-228422 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] With the progress of semiconductor miniaturization, the positioning accuracy required for stage driving devices is increasing year by year. In such "ultra-precision" actuators (driving devices), besides the resonance during stage driving considered in Patent Document 1, there may exist disturbance factors caused by the structure and operating mechanism of the actuator itself, the installation environment of the actuator, and the like.

[0005] The present invention has been made in view of these circumstances, and an object of the present invention is to provide a vibration processing apparatus and the like that enable further higher accuracy of actuators. [Means for Solving the Problems]

[0006] To solve the above problems, a vibration processing apparatus according to one aspect of the present invention comprises: a vibration data acquisition unit that collects vibration data when the actuator is not driven; a peak frequency identification unit that identifies at least one peak frequency in which a maximum value appears through frequency analysis of the vibration data; and a peak frequency output unit that outputs the peak frequency.

[0007] In this configuration, peaks that could act as disturbances are identified and output from vibration data when the actuator is not operating, which can then be used to take actions to further improve the accuracy of the actuator, such as suppressing its frequency components.

[0008] Another aspect of the present invention is a stage drive device. This device comprises an actuator, a stage driven by the actuator, a vibration data acquisition unit for collecting vibration data when the actuator is not driven, a peak frequency identification unit for identifying at least one peak frequency in which a maximum value appears through frequency analysis of the vibration data, and a peak frequency output unit for outputting the peak frequency.

[0009] Another aspect of the present invention is a vibration processing method. This method comprises a vibration data acquisition step of collecting vibration data when an actuator is not driven, a peak frequency identification step of identifying at least one peak frequency in which a maximum value appears through frequency analysis of the vibration data, and a peak frequency output step of outputting the peak frequency.

[0010] Furthermore, any combination of the above components, as well as conversions of the expression of the present invention between methods, apparatus, systems, recording media, computer programs, etc., are also valid embodiments of the present invention. [Effects of the Invention]

[0011] According to the present invention, the actuator can be made even more precise. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view of the air stage. [Figure 2] This is a cross-sectional view of an air actuator. [Figure 3] This is a functional block diagram of the actuator's vibration control device. [Figure 4] An example of the screen output by the peak frequency output unit is shown. [Modes for carrying out the invention]

[0013] The following describes in detail embodiments (hereinafter also referred to as "models") for carrying out the present invention, with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc., are denoted by the same reference numerals, and redundant descriptions are omitted. The scale and shape of each part shown in the drawings are set for convenience to simplify the description and are not to be interpreted restrictively unless otherwise specified. The embodiments are illustrative and do not limit the scope of the present invention in any way. Not all features or combinations thereof described in the embodiments are necessarily essential to the present invention.

[0014] The present invention can be applied to any type of actuator based on any principle (e.g., magnetism or electricity), but in this embodiment, a fluid actuator or air actuator that drives the target object with a working fluid such as air will be described.

[0015] Figure 1 is a perspective view of an air stage 100 to which the fluid actuator of this embodiment is applied. The air stage 100 comprises a base plate 102, a vibration isolation table 104, a vibration isolation device 106, a stage 110, one X-axis air actuator 120, and two Y-axis air actuators 130A and 130B (hereinafter collectively referred to as Y-axis air actuators 130). The base plate 102 is supported by the vibration isolation table 104. The air stage 100 is formed in an H-shape when viewed from above by the X-axis air actuator 120 as the upper axis and the two Y-axis air actuators 130A and 130B as the lower axis. The vibration isolation device 106 suppresses the transmission of vibrations from the floor or the like on which the air stage 100 is placed to the base plate 102.

[0016] The X-axis air actuator 120 and the Y-axis air actuator 130 are fluid actuators that drive the stage 110, which is the target of the drive, along the X and Y axes using air as the working fluid. The X-axis air actuator 120 has a guide 122 (square shaft), a slider 124, a servo valve 126 (not shown), and piping 128 (not shown). Similarly, the Y-axis air actuator 130 has a guide 132, a slider 134, a servo valve 136, and piping 138. The stage 110 is mounted on the slider 124. Both ends of the guide 122 are supported by the slider 134 of the Y-axis air actuator 130.

[0017] Sliders 124 and 134 constitute a drive unit that drives the stage 110, which is the object to be driven, along the X and Y axes. Servo valves 126 and 136 constitute a working fluid supply unit that supplies air to sliders 124 and 134 based on the intake and exhaust volume, which is the amount of air operating, calculated by the control device. Piping 128 and 138 allows air to flow between the drive unit and the working fluid supply unit. Position sensor 140 detects the position of the stage 110 in the X axis direction, and position sensor 142 detects the position of the stage 110 in the Y axis direction.

[0018] Figure 2 is a cross-sectional view of the air actuator. The X-axis air actuator 120 comprises a guide 122, a slider 124, a servo valve 126 (spool valve), and piping 128. Pressurized air is supplied between the outer circumferential surface of the guide 122 and the inner circumferential surface of the slider 124 to form a hydrostatic bearing. The slider 124, which floats above the guide 122 due to the pressurized air, can move smoothly in the X-axis direction without contacting the guide 122. The slider 124 is provided with an internal space called a servo chamber 150. The servo chamber 150 is divided into a positive chamber chamber 152 and a negative chamber chamber 154 by a pressure receiving plate 123 integrally formed with the guide 122.

[0019] The slider 124 is driven by a servo valve 126. The servo valve 126 controls the intake and exhaust flow rate of the control port depending on the position of the spool. The air actuators 120 and 130 for each axis include a pair of servo valves 126P and 126N disposed on the positive side and the negative side. The control port of the positive-side servo valve 126P communicates with the positive-side chamber 152 via the positive-side pipe 128P. The control port of the negative-side servo valve 126N communicates with the negative-side chamber 154 via the negative-side pipe 128N. The position of the slider 124 relative to the guide 122 (pressure receiving plate 123) is controlled by the differential pressure generated between the positive-side chamber 152 and the negative-side chamber 154 in accordance with the spool positions of the servo valves 126P and 126N. The above primarily describes the X-axis air actuator 120, but the Y-axis air actuator 130 can also be configured in the same manner as the X-axis air actuator 120.

[0020] Figure 3 is a functional block diagram of the vibration processing device 3 for actuators such as the X-axis air actuator 120 and the Y-axis air actuator 130. The vibration processing device 3 includes a vibration data acquisition unit 31, a peak frequency identification unit 32, a peak frequency output unit 33, a setting operation reception unit 34, a suppression target frequency setting unit 35, and a suppression target frequency storage unit 36. These functional blocks are realized through cooperation between hardware resources such as a central processing unit of a computer, a memory, an input device, an output device, and peripheral devices connected to the computer, and software executed using these resources. Regardless of the type or installation location of the computer, each of the above functional blocks may be realized by hardware resources of a single computer, or may be realized by combining hardware resources distributed among a plurality of computers. For example, part or all of the functional blocks of the vibration processing device 3 may be realized in a distributed or centralized manner by a computer or processor provided in an actuator (such as the X-axis air actuator 120 or the Y-axis air actuator 130) or a driving device (such as the air stage 100), or may be realized in a distributed or centralized manner by a computer or processor capable of wired or wireless communication with the actuator or the driving device.

[0021] In the stage controller 160, the control unit 2 of the air stage 100 and / or the air actuators 120, 130 performs feedback control on the air actuators 120, 130 based on the X position and Y position of the stage 110 measured by the position sensors 140, 142, and moves the stage 110 to target X and Y positions. Specifically, the control unit 2 generates an X valve command that determines the intake and exhaust volume of the X servo valve 126, which is the operation amount for the X actuator 120, based on the deviation (X position deviation) between the current X position of the stage 110 measured by the X position sensor 140 and the target X position (X position command) provided from the X position command unit 21. Similarly, the control unit 2 generates a Y valve command that determines the intake and exhaust volume of the Y servo valve 136, which is the operation amount for the Y actuator 130, based on the deviation (Y position deviation) between the current Y position of the stage 110 measured by the Y position sensor 142 and the target Y position (Y position command) provided from the Y position command unit 22.

[0022] The vibration data collection unit 31 collects vibration data of the stage 110 when the actuators 120 and 130 are not driven. Here, the term "non-driven" means when the stage 110, which is the driven object of the actuators 120 and 130, is stopped or stationary in the driving directions (X-axis direction, Y-axis direction) of the respective actuators 120 and 130. That is, when the stage 110 is stopped in the X-axis direction, the X actuator 120 is in a non-driven state, and when the stage 110 is stopped in the Y-axis direction, the Y actuator 130 is in a non-driven state. It is preferable that the vibration data of the stage 110 is collected by the vibration data collection unit 31 when both actuators 120 and 130 are non-driven, that is, when the stage 110 is stopped in both the X-axis direction and the Y-axis direction. However, the vibration data of the stage 110 may also be collected when one of the actuators 120 and 130 is non-driven. Note that, typically, the actuators 120 and 130 are energized even in the non-driven state, and servo control is performed with the stop position of the stage 110 as the target position.

[0023] The position (stopping position) of the stage 110 where the vibration data acquisition unit 31 collects vibration data can be any position within the movable range of the stage 110 in the X-axis and Y-axis directions. Figure 3 shows the positions of both ends in the X-axis and Y-axis directions as typical stopping positions, indicated by dotted lines. XL is the position of one end (left end) in the X-axis direction, XR is the position of the other end (right end) in the X-axis direction, YU is the position of one end (upper end) in the Y-axis direction, and YD is the position of the other end (lower end) in the Y-axis direction. In addition to or instead of these positions, the stage 110 may be stopped at the central position, indicated by the solid line in Figure 3, and the vibration data acquisition unit 31 may collect vibration data.

[0024] The collection of vibration data by the vibration data acquisition unit 31 and the processing by other functional blocks of the vibration processing device 3, described later, may be performed in the factory that manufactures the drive device such as the air stage 100 before shipment, or during setup and adjustment before full operation after installation in the facility where the drive device will be used, or during pauses in the operation of the drive device such as when the stage 110 is temporarily stopped or during waiting periods between operating times of the drive device.

[0025] The vibration data acquisition unit 31 collects vibration data when the actuators 120 and 130 are not driven, i.e., when the stage 110 is stopped, so it can effectively detect disturbance elements caused by the structure and operating mechanism of the actuators 120 and 130 themselves, the installation environment of the actuators 120 and 130, etc. It is also conceivable to collect vibration data when the actuators 120 and 130 are driven, i.e., when the stage 110 is moving, as described in Patent Document 1, but there is a high possibility that the static disturbance elements mentioned above will be masked by resonance and other vibrations associated with stage driving, which is the subject of Patent Document 1.

[0026] The vibration data acquisition unit 31 may directly acquire vibration data of the stage 110 when the actuators 120 and 130 are not driven, using position sensors 140 and 142 that detect vibrations as minute fluctuations in the position of the stage 110 in the X-axis and Y-axis directions, or vibration sensors attached to the stage 110, etc. Alternatively, the vibration data acquisition unit 31 may indirectly acquire vibration data of the stage 110 based on fluctuations in signals inside the control unit 2 while the stage 110 is stopped. When the stage 110 is stopped (not driven), macroscopically the current X position from the X position sensor 140 coincides with the target X position from the X position command unit 21, and the current Y position from the Y position sensor 142 coincides with the target Y position from the Y position command unit 22. However, in reality, microscopic vibrations cause a discrepancy between the current position and the target position, causing fluctuations in the signals inside the control unit 2, from which vibrations of the stage 110 can be indirectly detected.

[0027] The peak frequency identification unit 32 identifies at least one peak frequency in which a maximum value appears through frequency analysis of the vibration data collected by the vibration data acquisition unit 31. Specifically, the peak frequency identification unit 32 identifies the peak frequency in the frequency domain vibration data obtained by Fourier transforming the time domain vibration data collected by the vibration data acquisition unit 31. The peak frequency output unit 33 outputs the peak frequency identified by the peak frequency identification unit 32. The peak frequency output unit 33 displays an image or screen, such as the one shown in Figure 4, on the display of an operating terminal (computer, etc.) of the air stage 100 operator. The left side of Figure 4 displays the frequency domain vibration data obtained by the frequency analysis (Fourier transform) of the peak frequency identification unit 32, and the right side of Figure 4 displays information about the peak identified by the peak frequency identification unit 32.

[0028] The peak frequency output unit 33 outputs or displays peak frequencies up to a predetermined number, starting from the one with the largest maximum value. In the example in Figure 4, the predetermined number is 3, so the peak frequency output unit 33 outputs or displays up to 3 peak frequencies, starting from the one with the largest maximum value. Here, the maximum value or peak magnitude may be the absolute value of the peak (the "intensity" value shown in Figure 4), or the difference in intensity between the peak and its surroundings (the effective peak height). The peak frequency output unit 33 may output or display only peak frequencies of a predetermined frequency (e.g., 3 Hz) or higher. As will be described later, the peak frequencies output by the peak frequency output unit 33 are subject to removal by the filter 4, but if low-frequency components below 3 Hz are removed by the filter 4, for example, the operation of actuators 120 and 130 may become unstable. Therefore, it is preferable to exclude such low peak frequencies from the output target of the peak frequency output unit 33.

[0029] As a result of applying the peak detection criteria described above, in the example in Figure 4, two peaks—fewer than the maximum number of peaks that can be output per processing cycle (3)—are identified by the peak frequency identification unit 32 and displayed by the peak frequency output unit 33. On the left side of Figure 4, marks P1 and P2, which point to the two peaks, are displayed on the frequency-analyzed vibration data in the frequency domain. Each mark P1 and P2 is displayed on the vertical axis (intensity) position corresponding to the maximum value (intensity) of the peak it points to, and on the horizontal axis (frequency) position corresponding to the peak frequency. On the right side of Figure 4, the frequency (peak frequency) and intensity (maximum value) are displayed for each of the two peaks. Thus, the display of the peak frequencies and intensities (right side) along with the frequency-analyzed vibration data in the frequency domain (left side) in Figure 4 enhances the overall readability.

[0030] The peak frequency output unit 33 displays a setting operation reception unit 34 along with the peak frequency, which accepts the operation to set the peak frequency identified by the peak frequency identification unit 32 as the target frequency for suppression of the filter 4 (Figure 3) of the stage controller 160, which is capable of suppressing frequency components of predetermined target frequencies. As shown in Figure 4, for each of the two peak frequencies identified by the peak frequency identification unit 32, the setting operation reception unit 34 is displayed as a button that allows selection of "Apply Filter" to set it as the target frequency for suppression of the filter 4, and "Do Not Apply Filter" to not set it as the target frequency for suppression of the filter 4. The air stage 100 adjuster can easily switch between "Apply Filter" and "Do Not Apply Filter" by clicking or performing other operations on the setting operation reception unit 34 on the screen.

[0031] The suppression target frequency setting unit 35 sets the peak frequency that has been marked as "filter applied" by the setting operation reception unit 34 as the suppression target frequency for the filter 4. Alternatively, the suppression target frequency setting unit 35 may set the peak frequency identified by the peak frequency identification unit 32 and output by the peak frequency output unit 33 as the suppression target frequency for the filter 4 without going through the setting operation reception unit 34. In this case, a series of processes including vibration data collection by the vibration data acquisition unit 31, peak frequency identification by the peak frequency identification unit 32, peak frequency output by the peak frequency output unit 33, and setting of the suppression target frequency by the suppression target frequency setting unit 35 can be automated. Note that the setting or updating of the suppression target frequency of the filter 4 by the suppression target frequency setting unit 35 is performed when the actuators 120 and 130 are not driven, similar to the vibration data collection by the vibration data acquisition unit 31. When the actuators 120 and 130 are driven, the control unit 2 uses the filter 4 to precisely drive the stage 110, so it is preferable to avoid making changes to the suppression target frequency of the filter 4.

[0032] Filter 4 is a bandstop filter, such as a notch filter, capable of suppressing the frequency components of the suppression target frequencies set by the suppression target frequency setting unit 35. When the control unit 2 performs feedback control of the X actuator 120 and Y actuator 130 based on the X position deviation and Y position deviation, the filter 4 suppresses or removes the frequency components of the suppression target frequencies. For example, filter 4 is applied as a command filter to the X position command and Y position command from the X position command unit 21 and Y position command unit 22, and the suppression target frequency components included in the X position command and Y position command are removed. As a result, the influence of peaks such as P1 in Figure 4, which are disturbances to the feedback control, is reduced or removed, thereby improving the positioning accuracy of the stage 110 by the X actuator 120 and Y actuator 130. If the difference between multiple suppression target frequencies set by the suppression target frequency setting unit 35 is smaller than a predetermined value, filter 4 may be set to form a single bandstop filter or a single stopband that suppresses these multiple suppression target frequencies together.

[0033] The suppression target frequency storage unit 36 ​​stores the suppression target frequencies set by the suppression target frequency setting unit 35. By making the suppression target frequencies stored in the suppression target frequency storage unit 36 ​​set in the filter 4, an appropriate suppression target frequency can be set in the filter 4 without repeating a series of processes in the other functional blocks (31 to 35) of the vibration processing device 3, as long as the operating conditions of the air stage 100 do not change. The suppression target frequency storage unit 36 ​​may also store the position of the stage 110 where the peak frequency that becomes the suppression target frequency is detected or identified, along with the suppression target frequency.

[0034] For example, in Figure 3, the suppression target frequencies FL, FR, FU, and FD (peak frequencies) detected at each position XL, XR, YU, and YD may be stored in the suppression target frequency storage unit 36 ​​as pairs with the respective positions XL, XR, YU, and YD (FL,XL), (FR,XR), (FU,YU), and (FD,YD). In this case, when the air stage 100 is in operation, the suppression target frequency FL stored in the suppression target frequency storage unit 36 ​​is applied to the filter 4 when the stage 110 moves from position XL, the suppression target frequency FR stored in the suppression target frequency storage unit 36 ​​is applied to the filter 4 when the stage 110 moves from position XR, the suppression target frequency FU stored in the suppression target frequency storage unit 36 ​​is applied to the filter 4 when the stage 110 moves from position YU, and the suppression target frequency FD stored in the suppression target frequency storage unit 36 ​​is applied to the filter 4 when the stage 110 moves from position YD. In this way, by dynamically applying the suppression target frequency stored for each position of the stage 110, the positioning accuracy of the stage 110 can be further improved.

[0035] The present invention has been described above based on embodiments. The embodiments are illustrative, and it will be understood by those skilled in the art that various modifications are possible in combinations of their components and processing processes, and that such modifications also fall within the scope of the present invention.

[0036] The functional configurations of each device described in the embodiments can be realized using hardware resources, software resources, or through the collaboration of hardware and software resources. Hardware resources can include processors, ROMs, RAMs, and other LSIs. Software resources can include operating systems, applications, and other programs. [Explanation of symbols]

[0037] 2 control unit, 3 vibration processing unit, 4 filter, 31 vibration data acquisition unit, 32 peak frequency identification unit, 33 peak frequency output unit, 34 setting operation reception unit, 35 suppression target frequency setting unit, 36 suppression target frequency storage unit, 100 air stage, 110 stage, 120 X actuator, 130 Y actuator.

Claims

1. A vibration data acquisition unit that collects vibration data of an actuator that drives a stage when the stage is stationary and not being driven, A peak frequency identification unit identifies at least one peak frequency at which a maximum value appears through frequency analysis of the vibration data, A peak frequency output unit that outputs the aforementioned peak frequency, A suppression target frequency setting unit sets the peak frequency output by the peak frequency output unit as the suppression target frequency for the filter, and causes the filter to suppress the frequency component of the suppression target frequency, A vibration treatment device equipped with the following features.

2. The vibration processing apparatus according to claim 1, wherein the peak frequency output unit outputs a predetermined number of peak frequencies, starting from the one with the largest maximum value.

3. The vibration processing apparatus according to claim 1 or 2, wherein the peak frequency output unit outputs the peak frequency at or above a predetermined frequency.

4. The vibration processing apparatus according to any one of claims 1 to 3, wherein the peak frequency output unit displays the peak frequency.

5. The vibration processing apparatus according to claim 4, wherein the peak frequency output unit displays the maximum value at the peak frequency.

6. The vibration processing apparatus according to claim 4 or 5, wherein the peak frequency output unit displays the peak frequency together with the frequency-analyzed vibration data.

7. The vibration processing apparatus according to any one of claims 4 to 6, wherein the peak frequency output unit displays a mark indicating the maximum value and / or the peak frequency on the frequency-analyzed vibration data.

8. The vibration processing apparatus according to any one of claims 4 to 7, wherein the peak frequency output unit displays together the peak frequency a setting operation reception unit that accepts an operation to set the peak frequency as the suppression target frequency for a filter capable of suppressing frequency components of a predetermined suppression target frequency.

9. Actuator and A stage driven by the actuator, A vibration data acquisition unit for the actuator collects vibration data when the stage is stationary and not in operation, A peak frequency identification unit identifies at least one peak frequency at which a maximum value appears through frequency analysis of the vibration data, A peak frequency output unit that outputs the aforementioned peak frequency, A suppression target frequency setting unit sets the peak frequency output by the peak frequency output unit as the suppression target frequency for the filter, and causes the filter to suppress the frequency component of the suppression target frequency, A stage drive device equipped with the following features.

10. A vibration data acquisition step for an actuator that drives a stage, which collects vibration data of the stage when the stage is stationary and not being driven, A peak frequency identification step involves identifying at least one peak frequency at which a maximum value appears through frequency analysis of the vibration data, A peak frequency output step that outputs the aforementioned peak frequency, A suppression target frequency setting step in which the peak frequency output step outputs the peak frequency to be suppressed is set for the filter as the suppression target frequency, and the filter is instructed to suppress the frequency component of the suppression target frequency, A vibration treatment method comprising the following:

11. A vibration data acquisition step for an actuator that drives a stage, which collects vibration data of the stage when the stage is stationary and not being driven, A peak frequency identification step involves identifying at least one peak frequency at which a maximum value appears through frequency analysis of the vibration data, A peak frequency output step that outputs the aforementioned peak frequency, A suppression target frequency setting step in which the peak frequency output step outputs the peak frequency to be suppressed is set for the filter as the suppression target frequency, and the filter is instructed to suppress the frequency component of the suppression target frequency, A vibration processing program that causes a computer to execute.

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