Control device and control method for a linear stage

Abstract

The present invention provides a control device and control method for a linear stage that can shorten the travel distance of the reaction force stage. [Solution] A control device for a linear stage comprising a main stage that moves on a frame and a reaction force stage that moves on the frame to the opposite side from the main stage to suppress the influence of the reaction force of the main stage on the frame, comprising a filter 40 that extracts acceleration components relating to a predetermined frequency or higher from an acceleration signal for controlling the main stage, and a position generation unit 50 that generates a target position for the reaction force stage using the extracted signal extracted by the filter 40.

Description

[Technical Field]

[0001] The present disclosure relates to a control device and a control method for a linear stage. [Background Art]

[0002] A linear stage in which a stage serving as a mover moves on a gantry having a stator is used in industrial machinery such as machine tools, measuring instruments, and semiconductor manufacturing equipment. Since the motion accuracy of this linear stage greatly affects the quality and characteristics of products, demands for high-precision and high-speed positioning are increasing.

[0003] In such a linear stage, the reaction force generated when driving the main stage vibrates the gantry and degrades the control accuracy of the main stage. For example, Patent Document 1 discloses that a reaction force stage that moves in a direction opposite to the main stage is provided in addition to the main stage, thereby suppressing the reaction force caused by driving the main stage. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2007-67162 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] However, as described above, in the conventional linear stage described above, the main stage and the reaction force stage move in opposite directions to each other, so it is necessary to secure a sufficient movement range, which results in a problem that the gantry becomes large and a large installation space is required. Patent Document 1 does not discuss such a problem and cannot solve it.

[0006] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a control device and a control method for a linear stage that can shorten the movement distance of a reaction force stage. [Means for solving the problem]

[0007] The control device according to this disclosure is a control device for a linear stage comprising a first movable element that moves on a frame and a second movable element that moves on the frame to the opposite side from the first movable element to suppress the effect of the reaction force of the first movable element on the frame, comprising a first extraction unit that extracts acceleration components relating to a predetermined frequency or higher from an acceleration signal for controlling the first movable element, and a generation unit that generates a target position of the second movable element using the extracted signal extracted by the first extraction unit.

[0008] In this disclosure, the first extraction unit extracts acceleration components with a predetermined frequency or higher from the acceleration signal for controlling the first movable element, and the generation unit uses the extracted signal from the first extraction unit to generate the target position of the second movable element and sends it to the second movable element.

[0009] The control device according to this disclosure includes a first amplification unit that amplifies the acceleration signal based on the mass ratio of the first movable element and the second movable element and outputs it to the first extraction unit.

[0010] In this disclosure, the first amplification unit amplifies an acceleration signal for controlling the first movable element based on the mass ratio of the first movable element and the second movable element, and outputs it to the first extraction unit.

[0011] The control device according to this disclosure has a first extraction unit which is a high-pass filter.

[0012] In this disclosure, the first extraction unit is a high-pass filter that extracts acceleration components with frequencies above a predetermined frequency from the acceleration signal from the first amplification unit.

[0013] The control device according to this disclosure includes an auxiliary signal output unit that outputs an auxiliary acceleration signal obtained based on the tracking errors of the first and second movable elements to the generation unit, and the generation unit generates the target position of the second movable element based on the auxiliary acceleration signal from the auxiliary signal output unit and the extraction signal from the first extraction unit.

[0014] In this disclosure, the auxiliary signal output unit generates an auxiliary acceleration signal based on the tracking errors of the first and second movable elements and outputs it to the generation unit, and the generation unit generates the target position of the second movable element based on the auxiliary acceleration signal from the auxiliary signal output unit and the extraction signal from the first extraction unit and transmits it to the second movable element.

[0015] The control device according to this disclosure includes, in the auxiliary signal output unit, a second amplification unit that amplifies and outputs an acceleration signal obtained from the tracking error of the first movable element based on the mass ratio of the first movable element and the second movable element, and a subtraction unit that outputs the difference between the acceleration signal from the second amplification unit and the acceleration signal obtained from the tracking error of the second movable element.

[0016] In this disclosure, the second amplifier amplifies the acceleration signal obtained from the tracking error of the first movable element based on the mass ratio of the first and second movable elements and outputs it to the subtraction unit, which calculates and outputs the difference between the acceleration signal from the second amplifier and the acceleration signal obtained from the tracking error of the second movable element.

[0017] The control device according to this disclosure includes a second extraction unit in the auxiliary signal output unit that extracts acceleration components relating to frequencies other than the predetermined frequency from the acceleration signal from the subtraction unit.

[0018] In this disclosure, the second extraction unit extracts acceleration components related to frequencies other than the predetermined frequency from the acceleration signal from the subtraction unit and outputs them to the generation unit as the auxiliary acceleration signal, and the generation unit generates the target position of the second movable element based on the acceleration signal from the second extraction unit and the extracted signal from the first extraction unit.

[0019] A control method according to the present disclosure is a control method for a linear stage comprising a first mover that moves on a gantry, and a second mover that moves on the gantry to a side opposite to the first mover to suppress an influence exerted on the gantry by a reaction force of the first mover, wherein an acceleration component equal to or higher than a predetermined frequency is extracted from an acceleration signal for controlling the first mover, and a target position of the second mover is generated using the extracted extraction signal.

[0020] In the present disclosure, an acceleration component equal to or higher than a predetermined frequency is extracted from an acceleration signal for controlling the first mover, a target position of the second mover is generated using the extracted extraction signal and transmitted to the second mover. Effects of the Invention

[0021] According to the present disclosure, it is possible to provide a control device and a control method for a linear stage that can shorten the moving distance of a reaction stage. Brief Description of the Drawings

[0022] [Figure 1] FIG. 1 is a schematic explanatory diagram showing the configuration of a control device according to Embodiment 1 and a linear stage controlled by the control device. [Figure 2] FIG. 2 is a block diagram showing the configuration of a control system provided in the control device according to Embodiment 1. [Figure 3] FIG. 3 is a graph showing an example of an acceleration signal output from an acceleration generation unit. [Figure 4] FIG. 4 is a graph showing a target position of a main stage output from a position generation unit. [Figure 5] FIG. 5 is a graph showing a target position (target trajectory) of a reaction stage output from a position generation unit of the control device according to Embodiment 1. [Figure 6] FIG. 6 is a block diagram showing the configuration of a control system provided in the control device according to Embodiment 2. [Figure 7] FIG. 7 is a graph showing a target position (target trajectory) of a reaction stage output from a position generation unit of the control device according to Embodiment 2. [Figure 8]This graph shows the residual vibration of the linear stage (main stage) controlled by the control device according to Embodiment 2. [Modes for carrying out the invention]

[0023] The present invention will be described in detail below with reference to the drawings illustrating its embodiments. In the following description, a so-called linear stage, comprising a main stage as a movable element and a frame having a stator, will be used.

[0024] (Embodiment 1) Figure 1 is a schematic diagram illustrating the configuration of the control device 100 and the linear stage 10 controlled by the control device 100 according to Embodiment 1.

[0025] The linear stage 10 comprises a fixed block 4 as a stator, mounted on a frame 5, and a main stage 1 (first movable element) as a movable element that moves along the fixed block 4. The fixed block 4 extends in the longitudinal direction of the frame 5, and in addition to the main stage 1, a reaction force stage 2 (second movable element) is movably provided on the fixed block 4.

[0026] Main stage 1 is used for transporting goods, and reaction stage 2 suppresses the vibration of the frame 5 caused by the reaction force when main stage 1 is driven. In other words, reaction stage 2 cancels out the effect of the reaction force of main stage 1, i.e., the vibration of frame 5, by moving on frame 5 (fixed block 4) in the opposite direction to main stage 1. Thus, since reaction stage 2 needs to move in the opposite direction to main stage 1, the control target value of reaction stage 2 has the opposite sign (inverse vector) of the control target value of main stage 1.

[0027] The main stage 1 and the reaction stage 2 have a plurality of permanent magnets (not shown) arranged at equal pitches in the longitudinal direction of the fixed block 4, i.e., in the direction of movement of the main stage 1 and the reaction stage 2. In this embodiment, the main stage 1 and the reaction stage 2 have the same pitch, but this is not limited to this, and the pitches of the main stage 1 and the reaction stage 2 may be different.

[0028] Furthermore, the fixed block 4 has magnetic pole teeth (not shown) around which U-phase, V-phase, and W-phase coils are wound, respectively, which are alternately provided at equal pitches in the direction of movement of the main stage 1 and the reaction force stage 2.

[0029] When a three-phase alternating current is passed through the coil of the fixed block 4 to generate a magnetic field in the magnetic pole teeth, the permanent magnets of the main stage 1 and the reaction stage 2 are successively attracted and repelled by this magnetic field, generating thrust in the main stage 1 and the reaction stage 2, causing the main stage 1 and the reaction stage 2 to move linearly along the fixed block 4.

[0030] Furthermore, the fixed block 4 is provided with an encoder 3 in the longitudinal direction of the fixed block 4 for detecting the positions of the main stage 1 and the reaction stage 2. The encoder 3 outputs the detected positions of the main stage 1 and the reaction stage 2 to the control device 100. In this embodiment, the encoder 3 is shared between the main stage 1 and the reaction stage 2, but this is not the only option, and different encoders may be used for the main stage 1 and the reaction stage 2, respectively.

[0031] Furthermore, a control device 100 is connected to the linear stage 10. The control device 100 controls the positions of the main stage 1 and the reaction stage 2. More specifically, the control device 100 controls the positions of the main stage 1 and the reaction stage 2 by outputting their respective target positions.

[0032] Figure 2 is a block diagram showing the configuration of the control system provided in the control device 100 according to Embodiment 1. The control system of the control device 100 includes an acceleration generation unit 80 that generates an acceleration pattern, a position generation unit 50A that generates the target position of the main stage 1, and a position generation unit 50 that generates the target position of the reaction force stage 2. Furthermore, a conversion unit 20, an amplification unit 30 (first amplification unit), and a filter 40 (first extraction unit) are provided between the acceleration generation unit 80 and the position generation unit 50.

[0033] The acceleration generation unit 80 generates and outputs a rectangular wave-shaped acceleration pattern to control the position of the main stage 1. The output terminal of the acceleration generation unit 80 is branched; one end is connected to the input terminal of the position generation unit 50A, and the other end is connected to the input terminal of the conversion unit 20.

[0034] The position generation unit 50A generates the target position of the main stage 1 by performing integration and other processing on the acceleration signal input from the acceleration generation unit 80, and outputs it to the main stage 1. Since the position generation unit 50A has the same configuration as the position generation unit 50 which will be described later, a detailed explanation of the position generation unit 50A will be omitted.

[0035] Furthermore, the output terminal of the conversion unit 20 is connected to the input terminal of the amplification unit 30. The conversion unit 20 converts the acceleration signal vector from the acceleration generation unit 80 into an inverse vector and outputs it to the amplification unit 30.

[0036] Since vibration (force) is proportional to mass, if the masses of main stage 1 and reaction stage 2 are different, the target values ​​of main stage 1 and reaction stage 2 will also differ according to the difference in mass between main stage 1 and reaction stage 2. Therefore, in order to determine the target position of reaction stage 2, it is necessary to consider the difference in mass between main stage 1 and reaction stage 2. Therefore, the amplification unit 30 amplifies the acceleration signal from the acceleration generation unit 80 based on the mass ratio of the main stage 1 and the reaction force stage 2 and outputs it to the filter 40.

[0037] Specifically, the output terminal of the amplification unit 30 is connected to the input terminal of the filter 40, and the amplification unit 30 multiplies the acceleration signal from the acceleration generation unit 80 by the mass ratio of the main stage 1 and the reaction force stage 2 and outputs it to the filter 40.

[0038] The vibrations after the main stage 1 stops at the target position (hereinafter referred to as residual vibrations) are greatly influenced by acceleration signals with high frequencies, including the resonant frequency of the support frame 5, and less influenced by acceleration signals with low frequencies. Therefore, in order to suppress the vibrations of the support frame 5 caused by the reaction force of the main stage 1, it is effective to extract the acceleration signal components related to the resonant frequency of the support frame 5 and higher frequencies from the acceleration signal from the acceleration generation unit 80, which has been converted into an inverse vector by the conversion unit 20, and use them to control the reaction force stage 2.

[0039] Therefore, the filter 40 extracts acceleration signal components from the acceleration signal input from the amplification unit 30 that are above a predetermined frequency. In other words, the filter 40 extracts frequency components that are effective in suppressing vibrations caused by the reaction force of the main stage 1, and by removing frequency components other than those components, it leads to a reduction in the travel distance of the reaction force stage 2.

[0040] The filter 40 is preferably a high-pass filter. The high-pass filter preferably has a transfer function determined based on the resonant frequency of the mount 5. By adjusting the transfer function of the filter 40, the gain of the filter 40 can be adjusted to extract acceleration signal components with a desired predetermined frequency range from the acceleration signal input from the amplification unit 30. In addition to a high-pass filter, the filter 40 can also be a band-pass filter, or a combination or fusion of a high-pass filter and a band-pass filter.

[0041] The following is the transfer function G of filter 40. HPF This is an example of an expression that represents this. G HPF (S) = S / (S + ω) Here, S is the Laplace transformer and ω is the cutoff frequency.

[0042] For example, with respect to the peak value of the resonant frequency of the mount 5, the transfer function G is calculated using frequencies within the range of 10 to 0.1 times the peak value, including the peak value. HPF ) to be determined. Specifically, if the peak resonant frequency of the mount 5 is 24 Hz, then using 0.1 times that value, which is 2.4 Hz, ω can be calculated as "2.4 × 2 × π". This extracts acceleration signal components with frequencies above a predetermined level from the acceleration signal input from the amplification unit 30.

[0043] By setting the gain of the filter 40 for the resonant frequency to be suppressed to "1", and setting the gain of the filter 40 for other frequencies to a value considerably smaller than 1, vibrations of the support structure 5 caused by the reaction force of the main stage 1 can be suppressed more effectively. The output terminal of the filter 40 is connected to the input terminal of the position generation unit 50, and the acceleration signal component (extracted signal) extracted by the filter 40 is output to the position generation unit 50.

[0044] The position generation unit 50 includes a reference characteristic trajectory (NCT) 51 which represents the desired damping characteristics on the phase plane, and two integrators 52 and 53 which perform integration processing. By performing integration and other processing on the acceleration signal input from the filter 40, it generates the target position of the reaction force stage 2 and outputs it to the reaction force stage 2.

[0045] The control of the linear stage 10 (reaction stage 2) by the control device 100 according to Embodiment 1 will be described below.

[0046] The acceleration generation unit 80 generates a target acceleration signal (hereinafter referred to as the target acceleration signal) for controlling the main stage 1 and outputs it to the position generation unit 50A and the conversion unit 20.

[0047] Figure 3 is a graph showing an example of the acceleration signal output from the acceleration generation unit 80. Specifically, Figure 3 shows the target acceleration signal in the control of the main stage 1, with the horizontal axis representing time and the vertical axis representing acceleration. Figure 3A shows the target acceleration signal related to trapezoidal control (trapezoidal acceleration), and Figure 3B shows the target acceleration signal related to S-shaped control (S-shaped acceleration).

[0048] The position generation unit 50A performs integration and other processing on the acceleration signal input from the acceleration generation unit 80 to generate the target position of the main stage 1, and outputs it to the main stage 1.

[0049] Figure 4 is a graph showing the target position of the main stage 1 output from the position generation unit 50A. Specifically, Figure 4 shows the target trajectory for controlling the main stage 1, with the horizontal axis representing time and the vertical axis representing position. Figure 4A is the target trajectory for trapezoidal control, and Figure 4B is the target trajectory for S-shaped control. The curve of the S-shaped control target trajectory is smoother than that of the trapezoidal control target trajectory at the start point (around 0.2 seconds) and end point (around 0.4 seconds).

[0050] When an acceleration signal as shown in Figure 3 is input from the acceleration generation unit 80, the conversion unit 20 converts the vector of the acceleration signal into an inverse vector and outputs it to the amplification unit 30. The amplification unit 30 multiplies the acceleration signal from the acceleration generation unit 80 by the mass ratio of the main stage 1 and the reaction force stage 2 and outputs it to the filter 40. The filter 40 extracts acceleration signal components from the acceleration signal input from the amplification unit 30 that are above a predetermined frequency based on the resonant frequency of the frame 5, and outputs the extracted acceleration signal components to the position generation unit 50. The position generation unit 50 performs integration and other processing on the acceleration signal input from the filter 40 to generate the target position of the reaction force stage 2 and outputs it to the reaction force stage 2.

[0051] Figure 5 is a graph showing the target position (target trajectory) of the reaction force stage 2 output from the position generation unit 50 of the control device 100 according to Embodiment 1. In Figure 5, the horizontal axis represents time and the vertical axis represents position. Figure 5A corresponds to the target acceleration signal for trapezoidal control, and Figure 5B corresponds to the target acceleration signal for S-curve control.

[0052] For comparison with the control device 100 of this embodiment (HPF method) which uses filter 40, Figure 5 also shows the target position of the reaction force stage 2 generated by the conventional method without using filter 40. In Figure 5, the HPF method related to the control device 100 of this embodiment is shown with a dark solid line, and the conventional method is shown with a light solid line.

[0053] As can be seen from Figures 5A and 5B, in the case of the linear stage 10 according to Embodiment 1 using the HPF method, the travel distance of the reaction stage 2 is approximately 20 mm, whereas in the case of the conventional method without the filter 40, the travel distance of the reaction stage 2 is approximately 65 mm, meaning that the travel distance of the reaction stage 2 has been shortened by more than 70%.

[0054] As described above, the control device 100 according to Embodiment 1, by using a filter 40 in addition to the amplification unit 30 when controlling the reaction force stage 2 of the linear stage 10, can significantly shorten the travel distance of the reaction force stage 2 compared to the conventional method that uses only the amplification unit 30 without the filter 40. Therefore, the linear stage 10 can be made more compact, reducing costs and improving ease of installation.

[0055] In the above description, the control device 100 according to Embodiment 1 was explained using the case where it has one filter 40 as an example, but it is not limited to this. Since there may be multiple peak values ​​for the resonant frequency of the mounting frame 5, the control device 100 may be configured to selectively have multiple filters 40.

[0056] Furthermore, although the above description has taken as an example the case in which the control device 100 according to Embodiment 1 generates the target position of the reaction force stage 2 using an acceleration signal for controlling the main stage 1, it is not limited to this. For example, the target position of the reaction force stage 2 may be generated using a command value (e.g., current value) to the servo driver (not shown) of the main stage 1.

[0057] (Embodiment 2) Figure 6 is a block diagram showing the configuration of the control system provided in the control device 100 according to Embodiment 2. In the control device 100 according to Embodiment 2, a target position for controlling the reaction force stage 2 is generated based on the acceleration signal output from the filter 40 and the tracking error of the main stage 1 and the reaction force stage 2.

[0058] In the control device 100 according to Embodiment 2, the control system includes, as in Embodiment 1, an acceleration generation unit 80, a position generation unit 50A, a conversion unit 20, an amplification unit 30, a filter 40, and a position generation unit 50, which have already been described, and a detailed explanation will be omitted.

[0059] The control system in the control device 100 according to Embodiment 2 further includes an adder 60 and an auxiliary signal output unit 70. The adder 60 is provided between the filter 40 and the position generation unit 50, and the auxiliary signal output unit 70 is connected to the adder 60.

[0060] Specifically, one of the summing input terminals of the summing unit 60 is connected to the output terminal of the filter 40, the other summing input terminal of the summing unit 60 is connected to the output terminal of the auxiliary signal output unit 70, and the output terminal of the summing unit 60 is connected to the input terminal of the position generation unit 50. The summing unit 60 adds the signal from the auxiliary signal output unit 70 to the acceleration signal output from the filter 40 and outputs it to the position generation unit 50.

[0061] The auxiliary signal output unit 70 generates an acceleration signal based on the tracking error of the main stage 1 and the tracking error of the reaction force stage 2, and outputs it to the summing unit 60. For the sake of explanation, the acceleration signal output from the auxiliary signal output unit 70 will be referred to as the auxiliary acceleration signal.

[0062] The auxiliary signal output unit 70 includes two differentiators 71 and 72 that perform differential processing on the tracking error of the main stage 1 input from the encoder 3 (see Figure 1), two differentiators 73 and 74 that perform differential processing on the tracking error of the reaction force stage 2 input from the encoder 3, an amplification unit 75, a subtraction unit 76, a conversion unit 77, and a filter 78 (second extraction unit).

[0063] The tracking error of the main stage 1 is input from the encoder 3 to the input terminal of the differentiator 71. The output terminal of the differentiator 71 is connected to the input terminal of the differentiator 72, the output terminal of the differentiator 72 is connected to the input terminal of the amplifier 75, and the output terminal of the amplifier 75 is connected to the addition input terminal of the subtractor 76.

[0064] Furthermore, the tracking error of the reaction force stage 2 is input from encoder 3 to the input terminal of differentiator 73. The output terminal of differentiator 73 is connected to the input terminal of differentiator 74, and the output terminal of differentiator 74 is connected to the subtraction input terminal of subtraction unit 76.

[0065] Furthermore, the output terminal of the subtraction unit 76 is connected to the input terminal of the conversion unit 77, and the output terminal of the conversion unit 77 is connected to the input terminal of the filter 78.

[0066] When the tracking error of the main stage 1 is input from the encoder 3 to the auxiliary signal output unit 70 having this configuration, it is subjected to two differentiation processes by the differentiators 71 and 72 to be converted into an acceleration signal and output to the amplifier unit 75.

[0067] The amplification unit 75, like the amplification unit 30, amplifies the acceleration signal based on the tracking error of the main stage 1, which is input from the differentiator 72, based on the mass ratio of the main stage 1 and the reaction stage 2, and outputs it to the subtraction unit 76. That is, the amplification unit 75 multiplies the acceleration signal from the differentiator 72 by the mass ratio of the main stage 1 and the reaction stage 2 and outputs it to the subtraction unit 76. If the masses of the main stage 1 and the reaction stage 2 are different, the target values ​​of the main stage 1 and the reaction stage 2 will also differ according to the difference in mass between the main stage 1 and the reaction stage 2. In light of this, in order to determine the target position of the reaction stage 2, the amplification unit 75 amplifies the acceleration signal from the differentiator 72 according to the mass ratio of the main stage 1 and the reaction stage 2 and outputs it.

[0068] On the other hand, when the tracking error of the reaction force stage 2 is input to the auxiliary signal output unit 70 from the encoder 3, the differential units 73 and 74 perform two differentiation processes to convert it into an acceleration signal, which is then output to the subtraction unit 76.

[0069] The subtraction unit 76 calculates the difference between the acceleration signal from the amplification unit 75 and the acceleration signal output from the differentiator 74, which is based on the tracking error of the reaction force stage 2, and outputs it to the conversion unit 77. Similar to the conversion unit 20, the conversion unit 77 converts the acceleration signal vector from the subtraction unit 76 into an inverse vector and outputs it to the filter 78.

[0070] The filter 78 extracts components related to specific frequencies from the acceleration signal output from the subtraction unit 76 via the conversion unit 77. Here, the specific frequencies are the frequency components (or frequency bandwidth) used when the acceleration signal components were extracted by the filter 40, the frequency components obtained by adding other frequency components to such frequency components, and frequency components that can suppress residual vibrations of the main stage 1. In this way, the filter 78 avoids extracting acceleration signal components (frequency components) that have already been extracted and supplements them by extracting acceleration signal components related to peak values ​​other than the resonant frequency of the frame 5.

[0071] The filter 78 is a bandpass filter that selectively extracts acceleration signal components related to a specific frequency from among the multiple frequency acceleration signal components from the conversion unit 77 (subtraction unit 76).

[0072] The following is the transfer function G of filter 78. BPF This is an example of an expression that represents this. G BPF (S) = [S·ω / Q] ÷ [S 2+(ω / Q)+ω 2 )] Here, S is the Laplace transformer, ω is the cutoff frequency, and Q is 2.4 (when the bandwidth is 10 Hz). For example, if the peak resonant frequency of the frame 5 is 24 Hz, then when extracting the acceleration signal component related to 24 Hz, ω can be calculated as "24 × 2 × π".

[0073] In this way, the filter 78 selectively extracts acceleration signal components related to specific frequencies from the acceleration signal from the conversion unit 77 (subtraction unit 76) and outputs them to the addition unit 60. As a result, acceleration signals based on the tracking error of the main stage 1 and the tracking error of the reaction force stage 2 are fed back. That is, the difference in motion (difference in operation) between the main stage 1 and the reaction force stage 2 is fed back based on the mass ratio of the main stage 1 and the reaction force stage 2.

[0074] As described above, the output terminal of the filter 40 is connected to one of the summing input terminals of the summing unit 60, and the output terminal of the auxiliary signal output unit 70 is connected to the other summing input terminal of the summing unit 60. The summing unit 60 adds the acceleration signal output from the filter 40 to the auxiliary acceleration signal from the auxiliary signal output unit 70, i.e., the acceleration signal from the filter 78, and outputs the result to the position generation unit 50.

[0075] The position generation unit 50 generates the target position of the reaction force stage 2 based on the auxiliary acceleration signal from the auxiliary signal output unit 70 and the acceleration signal (extracted signal) from the filter 40. Specifically, the position generation unit 50 generates the target position of the reaction force stage 2 by performing integration or other processing on the acceleration signal, which is the sum of the auxiliary acceleration signal from the auxiliary signal output unit 70 and the acceleration signal from the filter 40, input from the addition unit 60, and outputs it to the reaction force stage 2.

[0076] Figure 7 is a graph showing the target position (target trajectory) of the reaction force stage 2 output from the position generation unit 50 of the control device 100 according to Embodiment 2. In Figure 7, the horizontal axis represents time and the vertical axis represents position. Figure 7A corresponds to the target acceleration signal for trapezoidal control, and Figure 7B corresponds to the target acceleration signal for S-curve control.

[0077] For comparison with the control device 100 of this embodiment (HPF+FB method) which uses the filter 40 and the auxiliary signal output unit 70, Figure 7 shows the target position of the reaction force stage 2 generated by the conventional method without using the filter 40 and the auxiliary signal output unit 70. In Figure 7, the "HPF+FB method" of the control device 100 of this embodiment is shown with a dark solid line, and the conventional method is shown with a light solid line.

[0078] As can be seen from Figures 7A and 7B, in the case of the linear stage 10 according to Embodiment 2 using the "HPF+FB method", the travel distance of the reaction force stage 2 is approximately 20 mm, whereas in the case of the conventional method that does not use the filter 40 and auxiliary signal output unit 70, the travel distance of the reaction force stage 2 is approximately 65 mm, meaning that the travel distance of the reaction force stage 2 has been shortened by more than 70%.

[0079] Figure 8 is a graph showing the residual vibration of the linear stage 10 (main stage 1) controlled by the control device 100 according to Embodiment 2. In Figure 8, the horizontal axis represents the time after the target trajectory is completed, and the vertical axis represents the tracking error. Figure 8A corresponds to the target acceleration signal for trapezoidal control, and Figure 8B corresponds to the target acceleration signal for S-curve control.

[0080] For comparison with the control device 100 of this embodiment, which uses the "HPF+FB method," Figure 8 also shows the tracking error (residual vibration) of the main stage 1 generated by the conventional method. In Figure 8, the "HPF+FB method" related to the control device 100 of this embodiment is shown with a dark solid line, and the conventional method is shown with a light solid line.

[0081] As can be seen from Figures 8A and 8B, in the case of the linear stage 10 according to Embodiment 2 using the "HPF+FB method", the settling time of the main stage 1 is shortened compared to when the conventional method is used. Here, the settling time is the time required until the tracking error falls within a predetermined range.

[0082] For example, when such a treatment range is set to 0.1 μm, the settling times in the control device 100 according to Embodiment 2 are 280 ms (Figure 8A) and 110 ms (Figure 8B), compared to 390 ms (Figure 8A) and 220 ms (Figure 8B) when using the conventional method, indicating a reduction in settling time.

[0083] As described above, in the control device 100 according to Embodiment 2, by using a filter 40 in addition to the amplification unit 30, the travel distance of the reaction force stage 2 of the linear stage 10 can be significantly reduced compared to the conventional method.

[0084] Furthermore, in the control device 100 according to Embodiment 2, as described above, the auxiliary signal output unit 70 feeds back acceleration signals based on the tracking error of the main stage 1 and the tracking error of the reaction force stage 2. Therefore, compared to the conventional method, residual vibration of the main stage 1 of the linear stage 10 can be suppressed. Thus, the accuracy of controlling the target position of the main stage 1 can be improved.

[0085] In the above description, the case in which the auxiliary signal output unit 70 of the control device 100 according to Embodiment 2 has one filter 78 has been used as an example, but the invention is not limited to this, and it may be configured to selectively have multiple filters 78.

[0086] Parts similar to those in Embodiment 1 are denoted by the same reference numerals, and detailed descriptions are omitted.

[0087] The technical features (constituent elements) described in Embodiments 1 and 2 are combinable with each other, and by combining them, new technical features can be conceived. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims, not in the sense described above, and all modifications within the sense and scope equivalent to the claims are intended.

[0088] The matters described in each embodiment can be combined with each other. Furthermore, the independent and dependent claims described in the claims can be combined with each other in any combination, regardless of the form of reference. In addition, the claims use a form in which claims referencing two or more other claims (multi-claim form), but are not limited to this. A form in which multi-claims referencing at least one multi-claim (multi-multi-claim) may also be used. [Explanation of symbols]

[0089] 1. Main Stage (First Movable Element) 2. Reaction force stage (second movable element) 5. Stand 10 Linear Stage 30 Amplification section (first amplification section) 40 Filter (First Extraction Section) 50 Position generation section (generation section) 70 Auxiliary signal output section 75 Amplification section (second amplification section) 76 Subtraction Unit 78 Filter (Second Extraction Section) 100 Control device

Claims

1. A control device for a linear stage comprising a first movable element that moves on a frame, and a second movable element that moves on the frame to the opposite side from the first movable element to suppress the effect of the reaction force of the first movable element on the frame, A first extraction unit that extracts acceleration components related to a predetermined frequency or higher from the acceleration signal for controlling the first movable element, A control device comprising: a generation unit that generates a target position for the second movable element using the extraction signal extracted by the first extraction unit.

2. The control device according to claim 1, further comprising a first amplification unit that amplifies the acceleration signal based on the mass ratio of the first movable element and the second movable element and outputs it to the first extraction unit.

3. The control device according to claim 1, wherein the first extraction unit is a high-pass filter.

4. The system includes an auxiliary signal output unit that outputs an auxiliary acceleration signal obtained based on the tracking errors of the first and second movable elements to the generation unit, The control device according to claim 1, wherein the generation unit generates the target position of the second movable element based on the auxiliary acceleration signal from the auxiliary signal output unit and the extraction signal from the first extraction unit.

5. The auxiliary signal output unit is, A second amplifier unit amplifies and outputs an acceleration signal obtained from the tracking error of the first movable element based on the mass ratio of the first movable element and the second movable element, The control device according to claim 4, further comprising a subtraction unit that outputs the difference between the acceleration signal from the second amplification unit and the acceleration signal obtained from the tracking error of the second movable element.

6. The auxiliary signal output unit is, The control device according to claim 5, further comprising a second extraction unit that extracts acceleration components relating to frequencies other than the predetermined frequency from the acceleration signal from the subtraction unit.

7. A control method for a linear stage comprising a first movable element that moves on a frame, and a second movable element that moves on the frame to the opposite side from the first movable element to suppress the effect of the reaction force of the first movable element on the frame, From the acceleration signal for controlling the first movable element, acceleration components relating to a predetermined frequency or higher are extracted. The extracted signal is used to generate the target position of the second movable element. Control method.

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