A control method for a non-rigid connection large-stroke high-precision motion platform

Abstract

The application provides a non-rigid connection large-stroke high-precision motion table control method, which avoids synchronous deviation and internal force coupling caused chattering instability by decomposing and compensating coarse and fine motion parasitic coupling disturbance force into stiffness, damping and unmodeled disturbance force, and realizes stable control of coarse and fine motion coordination; the method realizes parameter identification and disturbance force estimation by only relying on input and output data, without additional measurement mechanism and precise model, and has the effects of simplification and realization, and universality and expandability in engineering; the method has the effects of improving coarse and fine motion coordination and Y direction fast and accurate positioning through virtual spindle synchronous control and fine motion feedforward compensation, and realizes high-precision motion control; finally, the method realizes coarse and fine motion high-precision decoupling and overall control precision improvement through calculation and compensation of stiffness, damping and unmodeled disturbance force, and can be directly applied to the field of flat plate lithography to improve lithography precision of a lithography machine.

Description

Technical Field

[0001] This invention belongs to the field of ultra-precision equipment manufacturing, specifically relating to a control method for a non-rigid connection large-stroke high-precision motion table. Background Technology

[0002] The precision motion stage is a core component of flatbed lithography machines and CNC machine tools, and its motion performance directly affects the manufacturing accuracy of flatbeds and workpieces. For example, the mainstream 6th generation flatbed lithography machines currently require a motion stage speed of 800 mm / s and an acceleration of 5 m / s². 2 The stabilization time is less than 150ms, the stroke is 2m, the driving mass reaches 450Kg, and the repeatability accuracy requirement is less than 130nm, meeting the imaging accuracy requirements of the photolithography process. Traditional H-type coarse and fine motion stages with rigid connections are characterized by structural symmetry and high overall rigidity. However, due to the influence of the crossbeam, a complex decoupled dynamic model and a complex synchronization control algorithm need to be established, leading to difficulties in engineering applications.

[0003] The currently used H-type motion table with high rigidity connection enables complete coupling of the axis dynamics, but uneven internal forces between the axes and unknown disturbance coupling cause unbalanced motor output on both sides of the crossbeam, resulting in low drive efficiency, complex control algorithm, difficulty in completely eliminating motion table chatter, which is not conducive to further improvement of the motion table's speed and accuracy performance indicators. Moreover, the unbalanced torque over a long period of time causes irreversible damage to the rigid crossbeam structure and the guide rail structure. Summary of the Invention

[0004] The purpose of this invention is to provide a non-rigid connection large-stroke high-precision motion table control method for improving the accuracy of the motion table, reducing coarse and fine motion coupling, and optimizing the service life of the motion table guide rail.

[0005] To achieve the above objectives, the present invention employs a non-rigid connection, large-stroke, high-precision motion stage control method, comprising the following steps:

[0006] Step S1: Measure the coarse Y displacement and rotation angle: The displacement signal of coarse motor Y1 is detected by position sensor one, and the displacement signal of coarse motor Y2 is detected by position sensor two. The displacement measurement value in the coarse Y direction and the displacement measurement value of the coarse rotation angle θ are calculated from the two detected displacement signals.

[0007] Step S2: Set the target and control the current: Set the target position of the coarse rotation angle θ and the coarse rotation Y position. Calculate the error based on the displacement measurement value in the coarse rotation Y direction obtained in Step S1 and the set value of the coarse rotation Y position. Calculate the error based on the displacement measurement value of the coarse rotation angle θ obtained in Step S1 and the set value of the coarse rotation angle θ. The controller calculates the adjustment amount based on the error and calculates the current setting values ​​for coarse rotation motor 1 Y1 and coarse rotation motor 2 Y2 based on the adjustment amount.

[0008] Step S3: Feedforward compensation micro-motion Y: Input the acceleration information in the micro-motion Y direction into the coarse motion feedforward controller, and adopt the micro-motion feedforward control strategy to make the displacement of the coarse motion Y follow the micro-motion Y direction, so as to achieve fast and accurate position control in the Y direction.

[0009] Step S4: Compensation and decoupling of coarse and micro motion disturbances: The parasitic coupled disturbances between coarse motion Y and micro motion Y are compensated and decoupled to reduce the mutual interference between coarse and micro motions;

[0010] Step S5: In the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the stiffness coefficient estimate is calculated based on the motion data of the uniform motion segment;

[0011] Step S6: In the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the damping coefficient estimate is calculated based on the frequency domain characteristics.

[0012] Step S7: In the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the estimated value of the unmodeled disturbance force is calculated based on the disturbance observation value based on the nominal model and Q filter.

[0013] Preferably, in step S4, the parasitic coupling disturbance force between coarse motion Y and micro motion Y is decomposed and equivalently modeled using stiffness disturbance force, damping disturbance force, and unmodeled disturbance force.

[0014] Preferably, in step S5, the stiffness coefficient estimate is calculated based on the controller adjustment amount and position amount of the uniform motion segment.

[0015] Preferably, the stiffness value is calculated by linear fitting after obtaining the displacement and output force of the motion table during the uniform speed segment.

[0016] Preferably, in step S6, the damping coefficient estimate is calculated by identifying the frequency domain transfer function.

[0017] Preferably, in step S6, spectral data is obtained through pink noise excitation to complete the identification and calculation of the damping coefficient.

[0018] Preferably, the method further includes step S7, wherein in the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the unmodeled disturbance force is estimated based on the disturbance observations of the nominal model and the Q filter.

[0019] Preferably, the method for estimating the unmodeled disturbance force in step S7 involves estimating the unmodeled disturbance force using a disturbance observer based on a nominal model, and employing a Q-filter to filter high-frequency noise to avoid exciting high-frequency vibrations in the motion table.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) This invention employs a disturbance force compensation and decoupling method based on input-output data to decompose and compensate for parasitic coupled disturbance forces in terms of stiffness, damping, and unmodeled disturbance forces. This avoids chattering, instability, and structural damage caused by synchronization deviation and internal force coupling, and improves the stability and accuracy of coarse and fine motion coordinated control. It solves the problems of synchronization deviation and parasitic coupled disturbance forces between coarse motion Y and fine motion Y.

[0022] (2) The method proposed in this invention does not require additional measuring mechanisms or precise models of precision motion stages; it relies solely on system input and output data to complete parameter identification and control. This simplifies system implementation, reduces hardware dependence, and enhances the versatility and scalability of the method, facilitating practical engineering applications. It also overcomes the shortcomings of rigid connection structure control algorithms being complex and reliant on additional sensors or models.

[0023] (3) This invention employs a virtual spindle control strategy to synchronously control the displacement and rotation angle between the coarse dual-drive system. This effectively eliminates the internal forces caused by the asynchronous coarse dual drives, improving the overall coordination and reliability of the motion table. It solves the problem of synchronous control of coarse dual drives in the prior art.

[0024] (4) This invention introduces the acceleration information in the micro-motion Y direction into the coarse motion feedforward controller and adopts a feedforward control strategy with input compensation to achieve coarse Y-motion following control of micro-motion Y. This improves the fast response and accurate positioning capability in the Y direction, and realizes high-precision control under coarse and micro-motion coordination. It solves the problem of insufficient performance of coarse and micro-motion coordinated control.

[0025] (5) This invention uses data from uniform motion segments to fit the stiffness coefficient, identifies the damping coefficient using the frequency domain transfer function, and estimates the unmodeled disturbance force using a disturbance observer with a nominal model and a Q filter. This solves the problem of inaccurate modeling of parameters in coarse-fine motion parasitic coupling disturbance forces. It achieves effective compensation for stiffness, damping, and unmodeled disturbance forces, improves the accuracy of disturbance force estimation and decoupling, and thus enhances overall control performance.

[0026] (6) Furthermore, the control method of this invention is designed for large-stroke, high-precision motion stages with non-rigid connections, and is particularly suitable for the motion control of flatbed lithography in lithography machines. It improves the control accuracy and stability of the motion stage, thereby enhancing the lithography accuracy of the lithography machine, and has good engineering application value. Attached Figure Description

[0027] Figure 1 A schematic diagram of a non-rigid connection unidirectional dual-drive motion stage structure in the non-rigid connection large stroke high-precision motion stage control method provided in the embodiments of the present invention;

[0028] Figure 2A block diagram of a centroid-driven virtual spindle synchronous control system in a non-rigid connection large stroke high-precision motion table control method provided in an embodiment of the present invention;

[0029] Figure 3 for Figure 2 A partial enlarged view of the control system;

[0030] Figure 4 Block diagram of the coarse and fine motion following system in the non-rigid connection large stroke high precision motion stage control method provided in the embodiments of the present invention;

[0031] Figure 5 A schematic diagram of stiffness damping compensation in a non-rigid connection, large stroke, high precision motion table control method provided in an embodiment of the present invention;

[0032] Figure 6 A schematic diagram of damping correction in a non-rigid connection, large stroke, high precision motion table control method provided in an embodiment of the present invention;

[0033] Figure 7 A block diagram of a DOB-based coupling parameter identification system in a non-rigid connection large stroke high precision motion stage control method provided in an embodiment of the present invention;

[0034] Figure 8 The comparison diagram shows the results of using stiffness damping and disturbance observer compensation in the non-rigid connection large stroke high precision motion table control method provided in the embodiments of the present invention.

[0035] The serial numbers in the diagram are as follows:

[0036] 1-1, Position sensor one; 1-2, Position sensor two; 1-3, Hall sensor one; 1-4, Hall sensor two; 1-5, Hall sensor three. Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0038] like Figure 1 As shown, this embodiment provides a non-rigid connection unidirectional dual-drive motion stage structure in a non-rigid connection large stroke high-precision motion stage control method. The main body of the motion stage has a coarse motor Y1 and a coarse motor Y2 on both sides. A position sensor 1-1 is installed on the coarse motor Y1, and a position sensor 1-2 is installed on the coarse motor Y2, which are used to detect the displacement signals of the corresponding coarse motors.

[0039] The coarse motion motor Y1 is connected to the main body via three micro motors Y5, X1, and Y6. The coarse motion motor Y2 is connected to the main body via three micro motors Y3, X2, and Y4. Hall sensor 1-3 is mounted on micro motor X1. Hall sensors 1-4 and 1-5 are mounted on micro motor X2. These serve as "high-precision position eyes" for the coarse motion stage, providing real-time and accurate position feedback signals to the closed-loop control system through non-contact measurement, thereby achieving stable and accurate motion control of the coarse motion stage.

[0040] The steps of the control method for a non-rigid connection, large stroke, high-precision motion table are as follows:

[0041] Step S1: Measure the coarse Y displacement and rotation angle: (e.g.) Figure 2 and Figure 3 As shown, the displacement signal of coarse motor Y1 is detected by position sensor 1-1, and the displacement signal of coarse motor Y2 is detected by position sensor 1-2. The displacement measurement value in the coarse Y direction and the displacement measurement value in the coarse rotation angle θ are calculated from the two detected displacement signals.

[0042] The formulas for calculating the displacement measurement value in the coarse Y direction and the coarse rotation angle θ measurement value are as follows:

[0043]

[0044] Among them, l y1 , l y2 These represent the horizontal distances from the center of mass of the motion table to the two motors on either side when the table is at its geometric center position. The displacement signals y1 and y2 are measured by position sensor 1-1 and position sensor 1-2, respectively.

[0045] Step S2: Set the target and control the current: Set the coarse motion angle θ to 0. Set the coarse motion Y position as needed, which can be input by the control system or the user. Calculate the error based on the displacement measurement value in the coarse motion Y direction obtained in Step S1 and the set value of the coarse motion Y position. Calculate the error based on the measurement value of the coarse motion angle θ obtained in Step S1 and the set value of the coarse motion angle θ. The controller calculates the adjustment amount based on the above errors, and calculates the current setting values ​​for coarse motion motor 1 Y1 and coarse motion motor 2 Y2 based on the adjustment amount, using the following formula:

[0046]

[0047] Where, k ly1 k ly2 These are the motor thrust constants, x ss (t+τ) represents the displacement of the micro-stage in the X direction, obtained by the micro-stage position sensor. Fy F θ These are the adjustment amounts calculated by controller Y based on the coarse Y position error and controller θ based on the coarse rotation angle θ error, respectively.

[0048] The controller consists of a PID controller, a second-order low-pass filter, and multiple notch filters connected in series. The PID controller and the second-order low-pass filter are connected in series in the following form:

[0049]

[0050] Where Kp is the proportional gain, f i f is the integral frequency. d For the differential frequency, f lpf β is the filtering frequency of a second-order low-pass filter. lpf This represents the damping coefficient of a second-order low-pass filter.

[0051] The Notch filter takes the following form:

[0052]

[0053] Where, ω zero ω pole These are the zero and pole frequencies, respectively, β zero ,β pole These are the zero-point and pole-point damping, respectively.

[0054] Step S3: Feedforward compensation micro-motion Y: such as Figure 4 As shown, the acceleration information in the Y direction of the micro-motion is input into the coarse motion feedforward controller, and the feedforward control strategy with input compensation is used for following control to achieve fast and accurate position control in the Y direction.

[0055] Step S4: Compensation and decoupling of coarse and micro motion disturbances: The parasitic coupled disturbances between coarse motion Y and micro motion Y are compensated and decoupled, and equivalent models are performed using stiffness disturbance, damping disturbance, and unmodeled disturbance.

[0056] See the compensation for stiffness disturbance force plus damping disturbance force. Figure 5 An equivalent model is performed for the unmodeled perturbation force in relation to the coarse-fine motion parasitic coupling perturbation force, and the equivalent model is expressed as follows:

[0057]

[0058] Among them, F par e is the coarse-to-fine dynamic parasitic coupling perturbation vector; diff The coarse and fine relative displacement vectors in the Y direction detected by Hall sensor 1-3, Hall sensor 2-4 and Hall sensor 3-5; Let be the differential of the relative displacement vector, K and D be the coefficients of the stiffness-damping matrix to be calculated by this method, and Δ be the unmodeled disturbance to be calculated by this method.

[0059] Step S5: In the calculation of parasitic coupling disturbance force compensation and decoupling for coarse and fine motion, the stiffness coefficient estimate is calculated based on the controller adjustment and position of the uniform motion segment. First, the stiffness coefficient of the stiffness disturbance force is calculated. An interferometer measurement system is used for closed-loop control in the fine motion stage, while a position encoder is used to control the coarse motion stage, keeping it stationary. The uniform motion segment of the trajectory generator is used as the system excitation signal for the fine motion stage. Since the fine motion stage is air-supported, the air-bearing friction is approximately zero, the damping force term is constant, and the unmodeled disturbance term Δ is not considered. At this point, the following equation applies:

[0060] In the calculation of coarse and fine dynamic parasitic coupling disturbance dynamics compensation and decoupling:

[0061] F ctrl =K·e diff +Ω

[0062] The controller output force F ctrl With e diff Given that Ω is the damping force constant, the stiffness coefficient K is determined by linear fitting, and random errors are eliminated by averaging the values ​​from multiple motions.

[0063] Step S6: In the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the spectrum data is obtained by pink noise excitation, the identification is completed and the damping coefficient of the damping disturbance force is calculated. The fine motion is controlled by an interferometer measurement system, and the coarse motion is controlled by Hall sensor 1-3, Hall sensor 2-4 and Hall sensor 3-5. The unmodeled disturbance Δ is not considered.

[0064] The transfer function of parasitic disturbance force:

[0065] H par =K+D·s=d diff / e diff

[0066] Where K and D are the stiffness damping matrix coefficients in step S4, respectively. diff is the coarse-to-fine dynamic parasitic coupling perturbation force. s is the Laplace operator.

[0067] The closed-loop transfer function of the parasitic disturbance force is:

[0068] H par_close =ctrl ss / e diff

[0069] Among them ctrl ss This refers to the adjustment amount of the micro-motion controller.

[0070] The closed-loop transfer function of the system can be equivalent to:

[0071] H close =ctrl ss / d diff

[0072] Among them, H par_close H close Applied to Figure 6 Pink noise is added at point e in the equation, and the result is obtained using the closed-loop frequency domain transfer function identification method.

[0073] Combining the above conditions, we can obtain the following transformation:

[0074]

[0075] Where a is the real part of the transfer function obtained by the closed-loop frequency domain transfer function identification method, b is the imaginary part of the transfer function obtained by the closed-loop frequency domain transfer function identification method, and i is the general mathematical description of the imaginary number, which is not a variable and therefore does not need to be specially marked.

[0076] The damping coefficient is then:

[0077] D = b / 2πf

[0078] Where f is the system sampling frequency. D is the damping matrix coefficient in step S4.

[0079] Step S7: In the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the unmodeled disturbance force is calculated. A disturbance observer based on the nominal model and Q filter is used to estimate the unmodeled disturbance force. The control block diagram is as follows: Figure 7 As shown, it can be done through Figure 7 z in -m The filter delay is compensated. Considering that parasitic coupling disturbances mainly act in the mid-to-low frequencies, G... n The nominal model of the controlled object in the low to medium frequency range can be taken as 1 / ms. 2 .

[0080]

[0081] The Q filter is a second-order low-pass filter, with the second-order low-pass cutoff frequency ω set to half the bandwidth of the micro-motion control system, and the damping β set to 0.707.

[0082] like Figure 8As shown in the figure, "with" represents using the algorithm, and "without" represents not using the algorithm. Table 1 shows that the disturbance observer based on the nominal model and Q-filter suppresses unmodeled disturbance frequencies below the second-order low-pass cutoff frequency, improving the amplitude of the control error. The compensation for the stiffness damping β estimate positively impacts the moving average (MA) of the uniform velocity segment, improves the effect of DOB on moving standard deviation (MSD), reduces motion error, and enhances motion performance.

[0083] Table 1 Comparison of MA and MSD

[0084]

[0085] This embodiment decomposes parasitic coupled disturbance forces into stiffness disturbance forces, damping disturbance forces, and unmodeled disturbance forces in the compensation and decoupling calculations of coarse and fine motion parasitic coupling disturbance forces, and performs equivalent modeling and compensation for each. This avoids chattering, instability, and structural damage caused by synchronization deviation and internal force coupling, achieving stability and high precision under coarse and fine motion coordinated control. By relying solely on system input and output data for parameter identification and disturbance force estimation, without the need for additional measuring mechanisms or precise motion table models, the method achieves simplicity and low hardware dependence, demonstrating scalability and versatility in practical engineering. By adopting a control strategy based on a virtual spindle to synchronously control the displacement and rotation angle of the coarse motion unidirectional dual drive, the method eliminates the internal forces caused by dual drive asynchrony, achieving coordination and reliability of the overall coarse motion. By controlling the micro motion in the Y direction... The acceleration information is input to the coarse motion feedforward controller, and a feedforward control strategy with input compensation is adopted, so that the displacement of coarse motion Y can follow that of micro motion Y. This improves the fast response and accurate positioning in the Y direction, and realizes high-precision position control under the coordination of coarse and micro motions. By calculating the stiffness coefficient from the controller output force and displacement in the uniform motion segment data, identifying the damping coefficient by combining the frequency domain transfer function, and estimating the unmodeled disturbance force by using a disturbance observer based on the nominal model and Q filter, the stiffness, damping and unmodeled disturbance force can be accurately compensated, and high-precision decoupling of parasitic disturbance forces of coarse and micro motions is achieved. Finally, by applying the above control method to a non-rigid connection large stroke high-precision motion stage, the overall control accuracy and stability of the motion stage are improved, realizing the application value of improving the control accuracy of the motion stage and the lithography accuracy of the lithography machine in the field of flatbed lithography technology.

[0086] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0087] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0088] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A control method for a non-rigidly connected, large-stroke, high-precision motion stage, characterized in that: Includes the following steps: Step S1: Measure the coarse Y displacement and rotation angle: The displacement signal of coarse motor Y1 is detected by position sensor 1 (1-1), and the displacement signal of coarse motor Y2 is detected by position sensor 2 (1-2). The displacement measurement value in the coarse Y direction and the displacement measurement value of the coarse rotation angle θ are calculated from the two detected displacement signals. Step S2: Set targets and control current: Set the target position of coarse rotation angle θ and the target position of coarse rotation Y. Calculate the error based on the displacement measurement value of the coarse rotation Y direction obtained in Step S1 and the set value of the coarse rotation Y position. Calculate the error based on the displacement measurement value of the coarse rotation angle θ obtained in Step S1 and the set value of the coarse rotation angle θ. The controller calculates the adjustment amount based on the error. Calculate the current setting values ​​of coarse rotation motor 1 Y1 and coarse rotation motor 2 Y2 based on the adjustment amount. Step S3: Feedforward compensation micro-motion Y: Input the acceleration information in the micro-motion Y direction into the coarse motion feedforward controller, and adopt the micro-motion feedforward control strategy to make the displacement of the coarse motion Y follow the micro-motion Y direction, so as to achieve fast and accurate position control in the Y direction. Step S4: Compensation and decoupling of coarse and micro motion disturbances: The parasitic coupled disturbances between coarse motion Y and micro motion Y are compensated and decoupled to reduce the mutual interference between coarse and micro motions; Step S5: In the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the stiffness coefficient estimate is calculated based on the motion data of the uniform motion segment; Step S6: In the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the damping coefficient estimate is calculated based on the frequency domain characteristics. Step S7: In the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the estimated value of the unmodeled disturbance force is calculated based on the disturbance observation value based on the nominal model and Q filter.

2. The non-rigid connection large stroke high-precision motion stage control method according to claim 1, characterized in that, In step S4, the parasitic coupling disturbance force between coarse motion Y and micro motion Y will be decomposed and equivalently modeled using stiffness disturbance force, damping disturbance force, and unmodeled disturbance force.

3. The non-rigid connection large stroke high-precision motion stage control method according to claim 1, characterized in that, In step S5, the stiffness coefficient estimate is calculated based on the controller adjustment amount and position amount of the uniform motion segment.

4. The non-rigid connection large stroke high-precision motion stage control method according to claim 3, characterized in that, The stiffness value is calculated by linear fitting after obtaining the displacement and output of the motion table during the uniform speed segment.

5. The non-rigid connection large stroke high-precision motion stage control method according to claim 1, characterized in that, In step S6, the damping coefficient estimate is calculated by identifying the frequency domain transfer function.

6. The non-rigid connection large stroke high-precision motion stage control method according to claim 5, characterized in that, In step S6, spectrum data is obtained through pink noise excitation to complete the identification and calculation of the damping coefficient.

7. The non-rigid connection large stroke high-precision motion stage control method according to claim 1, characterized in that, It also includes step S7, which is: in the calculation of coarse and fine motion parasitic coupling disturbance force compensation and decoupling, the unmodeled disturbance force is estimated based on the disturbance observations of the nominal model and Q filter.

8. The non-rigid connection large stroke high-precision motion stage control method according to claim 7, characterized in that, The method for estimating the unmodeled disturbance force in step S7 involves estimating the unmodeled disturbance force using a disturbance observer based on a nominal model, and using a Q filter to filter high-frequency noise to avoid exciting high-frequency vibrations of the motion table.

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