Precise motion compensation device applying stick-slip friction mechanism and control method thereof

Abstract

The invention relates to the technical field of precision motion, in particular to a precision motion compensation device applying a stick-slip friction mechanism and a control method thereof.The precision motion compensation device comprises a base, a top plate and a PID controller, the top plate and the base are connected through two sets of crossed roller guide rails, and the middle of the base is connected with a stick-slip actuator; the parameters of the PID controller are globally optimized through an eddy current search algorithm, the dynamic performance and the steady-state precision of the PID controller can be remarkably improved, the system can keep stable operation under the non-linear and high-frequency disturbance condition, a two-stage motion control strategy is adopted, when an error value is larger than a preset threshold value, rough positioning is carried out through the maximum step length, and the precision of the system is improved. According to the method, the target position is rapidly approached, the control response speed is improved, when the error is smaller than or equal to the preset threshold value, the fine motion mode after PID controller parameter optimization is switched to, high-precision final positioning is achieved, balance between the response speed and the control precision is achieved, and the comprehensive performance of motion control is improved.

Description

Technical Field

[0001] The present invention relates to the field of precision motion technology, and in particular to a precision motion compensation device using a stick-slip friction mechanism and a control method thereof. Background Art

[0002] Precision motion compensators are widely used in semiconductor manufacturing, optical systems, precision measurement and other fields. Their control systems have extremely high requirements on response speed, positioning accuracy and stability. The PID (proportional-integral-differential) control algorithm is one of the most widely used classic control methods in the field of industrial control. It is known for its simple structure and good robustness. It can achieve high-precision closed-loop control and is therefore widely used in automation control systems.

[0003] However, the performance of the PID controller is highly sensitive to the selection of its parameters (proportional coefficient Kp, integral coefficient Ki, differential coefficient Kd). If the parameters are not selected properly, it may cause the system to respond too slowly, overshoot too much, or even become unstable, which will significantly affect the control performance. In addition, since the precision motion compensator involves complex factors such as nonlinear characteristics, high-frequency disturbances, and stick-slip friction mechanisms (such as stick-slip piezoelectric motors and precision positioning platforms), it is difficult to balance the control accuracy and control response speed when using a PID controller to control the precision motion compensator. Summary of the invention

[0004] In order to overcome the deficiencies of the prior art, an object of the present invention is to provide a precision motion compensation device and a control method thereof using a stick-slip friction mechanism, which has high stability, improves control response speed and simultaneously improves control accuracy.

[0005] The technical solution adopted by the present invention is: A precision motion compensation device using a stick-slip friction mechanism comprises a base and a top plate arranged above the base, and also comprises a PID controller. The top plate and the base are connected by two sets of cross roller guides. A stick-slip actuator is connected to the middle of the base. The stick-slip actuator comprises a driving block, a piezoelectric ceramic component, and a flexible transmission structure abutting the piezoelectric ceramic component. The driving block is mounted on the top of the flexible transmission structure, and its upper side surface abuts the lower side surface of the top plate. A boss is connected to the top of the top plate, and a laser displacement sensor is arranged on one side of the boss. The laser displacement sensor and the piezoelectric ceramic component are both electrically connected to the PID controller.

[0006] Preferably, both sides of the base are connected with first screws through threads, and the two first screws are respectively abutted against the back sides of the two groups of cross roller guide rails.

[0007] The present invention also provides a control method for a precision motion compensation device using a stick-slip friction mechanism, comprising the following steps: S1, using a laser displacement sensor to detect the current position of the boss in real time, and calculating the error value between the current position and the set target position through a PID controller; S2. When the error value is greater than a preset threshold, the stick-slip actuator is controlled to drive the top plate to move continuously in steps with a maximum step length; S3. When the error value is less than or equal to the preset threshold, the eddy current search algorithm is used to optimize and adjust the initial parameters of the PID controller to obtain the optimal parameters of the PID controller; S4, the PID controller outputs an electrical signal to the piezoelectric ceramic component according to the optimal parameters, so that the stick-slip actuator drives the top plate to move continuously in steps with an optimal step length according to the current electrical signal.

[0008] Preferably, after step S4, the method further includes the following steps: S5. Determine whether the error value is less than or equal to the preset accuracy value. If so, stop driving the stick-slip actuator. If not, return to step S3.

[0009] Preferably, in step S3, the initial parameters of the PID controller are adjusted using an eddy current search algorithm, and the specific steps for obtaining the optimal parameters of the PID controller are: S31, determining the initial parameters of the PID controller based on empirical rules, determining the number of eddy current search particles, the maximum number of iterations, and the upper and lower bounds of the d-dimensional search space according to the initial parameters, and setting the fitness function value of the eddy current center to infinity; S32. Calculate the eddy center and vortex radius , eddy center Calculation formula and eddy current radius The calculation formulas are expressed as follows:

[0010] ; in, is the upper bound of the d-dimensional search space, is the lower bound of the d-dimensional search space, , , is the inverse incomplete gamma function, is a parameter in the inverse incomplete gamma function, which takes the value 1; S33, draw a circle with the current eddy center as the center and the current eddy radius as the radius, use Gaussian distribution to sample within the circle and generate a candidate solution set consisting of multiple eddy search particles, the candidate solution set It is expressed as: ; in, Search particle number for eddy current, is the current iteration number; S34, calculate the fitness function values ​​of all eddy current search particles, and extract the minimum value from the fitness function values ​​of all eddy current search particles, and determine whether the minimum value is less than the fitness function value of the current eddy current center. If so, the eddy current search particle corresponding to the minimum value is used as the current eddy current center. It is expressed as: ; in, Search for particles for the eddy current corresponding to the minimum value; S35, determine whether the current number of iterations is equal to the maximum number of iterations, if so, use the current eddy center particle value as the optimal parameter of the PID controller , otherwise the radius is adjusted and the process returns to step S33. The formula for adjusting the radius is expressed as: , ; in, is the maximum number of iterations, is the current iteration number, , is the radius of the tth iteration, , , is the inverse incomplete gamma function, is a parameter in the inverse incomplete gamma function.

[0011] Preferably, in step S33, the formula for sampling within the circle using Gaussian distribution is expressed as: ; in, is the probability density function, which represents the random variable The probability of being selected, is a d×1 dimensional random variable, is the vortex center vector, is the covariance matrix, , is the d-dimensional identity matrix, for The determinant of for The inverse matrix of .

[0012] Preferably, in step S33, the specific steps of sampling within a circle using Gaussian distribution and generating a candidate solution set consisting of a plurality of eddy current search particles are: S331, sampling within the circle using Gaussian distribution and generating a candidate solution set consisting of a plurality of eddy current search particles; S332, perform boundary constraint processing on each eddy current search particle in the candidate solution set. The boundary constraint processing formula of each eddy current search particle is expressed as: ; in, is the set of nearest solutions in the tth iteration The value of the kth eddy current search particle. When the value of the eddy current search particle is less than the lower bound When taking the lower bound When the value of the eddy current search particle is greater than the upper bound When taking the upper bound otherwise, keep the original value unchanged.

[0013] Preferably, in step S34, the specific steps of calculating the fitness function values ​​of all eddy current search particles are: S341, using each eddy current search particle as a parameter input of the PID controller, predicting the boss position after executing h moves, S342, calculating the fitness function value of each eddy current search particle according to the preset boss target position and the boss predicted position, and the calculation formula of the fitness function value of each eddy current search particle is expressed as: ; in, is the fitness function value, To predict the boss position after h moves, is the boss target position.

[0014] Preferably, the rule of thumb is the Ziegler-Nichols rule of thumb or the Chien-Hrones-Reswick rule of thumb.

[0015] The beneficial effects of the present invention are: This precision motion compensation device and control method using the stick-slip friction mechanism globally optimizes the PID controller parameters through an eddy current search algorithm, which can significantly improve the dynamic performance and steady-state accuracy of the PID controller, provide a better control scheme for complex nonlinear systems, and enable the system to maintain stable operation under nonlinear and high-frequency disturbance conditions. A two-stage motion control strategy is adopted. When the error value is greater than a preset threshold, the maximum step size is used for rough positioning to quickly approach the target position and improve the control response speed. When the error is less than or equal to the preset threshold, the device switches to the fine motion mode after the PID controller parameters are optimized to achieve high-precision final positioning, achieve a balance between response speed and control accuracy, and improve the comprehensive performance of motion control. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A three-dimensional schematic diagram of a precision motion compensation device that applies a stick-slip friction mechanism.

[0017] Figure 2 Schematic diagram of the partial structure of a precision motion compensation device that applies the stick-slip friction mechanism.

[0018] Figure 3 for Figure 2 Schematic diagram of the structural decomposition.

[0019] Figure 4 Schematic diagram of the internal structure of a precision motion compensation device that applies a stick-slip friction mechanism.

[0020] Figure 5 The present invention is a flow chart of a control method for a precision motion compensation device using a stick-slip friction mechanism.

[0021] Figure 6 Schematic diagram of the iteration of the eddy current search algorithm.

[0022] In the figure: 1. base; 2. top plate; 3. cross roller guide; 4. drive block; 5. flexible transmission structure; 6. boss; 7. laser displacement sensor; 8. first screw; 9. second screw; 10. third screw; 11. fourth screw; 12. double parallel plate flexible hinge; 13. mounting block; 14. piezoelectric ceramic component. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] See also Figure 1-Figure 4 The present invention provides a technical solution: a precision motion compensation device using a stick-slip friction mechanism, comprising a base 1 and a top plate 2 arranged above the base 1, and also comprising a PID controller, the top plate 2 and the base 1 are connected via two sets of cross roller guide rails 3, a stick-slip actuator is connected to the middle of the base 1, the stick-slip actuator comprises a driving block 4, a piezoelectric ceramic component 14 and a flexible transmission structure 5 abutting against the piezoelectric ceramic component 14, the driving block 4 is mounted on the top of the flexible transmission structure 5, and its upper side abuts against the lower side of the top plate 2, a boss 6 is connected to the top of the top plate 2, a laser displacement sensor 7 is arranged on one side of the boss 6, and the laser displacement sensor 7 and the piezoelectric ceramic component 14 are both electrically connected to the PID controller; The top plate 2 is driven by the stick-slip actuator so that the top plate 2 moves relative to the base 1 through the cross roller guide 3, and the boss 6 moves with the top plate 2. The current position of the boss 6 is detected in real time by the laser displacement sensor 7, and the error value between the current position and the set target position is calculated by the PID controller. When the error value is greater than the preset threshold, the stick-slip actuator is controlled to drive the top plate 2 to perform continuous stepping movement with the maximum step length, thereby quickly approaching the target position and improving the control response speed. When the error value is less than or equal to the preset threshold, the eddy current search algorithm is used to optimize and adjust the initial parameters of the PID controller to obtain the optimal parameters of the PID controller, which can significantly improve the dynamic performance and steady-state accuracy of the PID controller, provide a better control scheme for complex nonlinear systems, and enable the system to maintain stable operation under nonlinear and high-frequency disturbance conditions. The PID controller outputs an electrical signal to the piezoelectric ceramic component 14 according to the optimal parameters, so that the stick-slip actuator drives the top plate 2 to perform continuous stepping movement with the optimal step length according to the current electrical signal, and achieves high-precision final positioning, achieving a balance between response speed and control accuracy, and improving the comprehensive performance of motion control. The principle of the stick-slip actuator driving the top plate 2 to move in steps is as follows: the piezoelectric ceramic component 14 can be composed of multiple layers of piezoelectric ceramics stacked in sequence. By utilizing the inverse piezoelectric effect of the piezoelectric ceramic component 14, the piezoelectric ceramic component 14 produces corresponding deformation after power is turned on, thereby converting electrical energy into mechanical energy. The flexible transmission structure 5 serves as a transmission mechanism to transmit the deformation of the piezoelectric ceramic component 14 to the driving block 4. When the piezoelectric ceramic component 14 recovers its deformation, the flexible transmission structure 5 recovers to its initial shape through elasticity, so that the driving block 4 periodically pushes the top plate 2 to move continuously in steps along the cross roller guide 3 through the stick-slip friction principle. The stick-slip friction principle involves two different friction states, namely the adhesion stage and the sliding stage. In the adhesion stage, The relative sliding between the contact surface of the driving block 4 and the top plate 2 has not yet begun. At this time, the friction force exists in the form of static friction. The driving block 4 pushes the top plate 2 forward by the static friction. When the piezoelectric ceramic component 14 reaches the maximum deformation set by the electrical signal, the piezoelectric ceramic component 14 is controlled to quickly retract to the initial state, and at the same time, the driving block 4 is driven to reset through the flexible transmission structure 5. Due to the existence of inertia, the top plate 2 cannot move synchronously with the driving block 4 in time, but remains in the original position. Relative sliding is formed between the contact surface of the driving block 4 and the top plate 2. At this time, the friction force exists in the form of dynamic friction. These two stages cause the top plate 2 to produce a net displacement. Repeating the two stages of adhesion and sliding allows the top plate 2 to move forward continuously.

[0025] In order to facilitate improving the matching accuracy between the top plate 2 and the base 1 so as to meet the requirements of high-precision movement for parallelism and posture, in the present embodiment, preferably, both sides of the base 1 are connected with first screws 8 through threads, and the two first screws 8 are respectively abutted against the back side of the two sets of cross roller guides 3, so as to press the cross roller guides 3 toward the top plate 2 through the first screws 8 on the base 1 to prevent looseness between the cross roller guides 3 and the top plate 2, thereby improving the matching accuracy between the top plate 2 and the base 1 and meeting the requirements of high-precision movement for parallelism and posture.

[0026] In order to facilitate the adjustment of the positive pressure of the contact between the driving block 4 and the top plate 2, and thus change the magnitude of the friction force, in the present embodiment, preferably, the top of the flexible transmission structure 5 is connected with a double parallel plate flexible hinge 12, and a mounting block 13 is provided in the middle of the double parallel plate flexible hinge 12, the driving block 4 is fixed to the top of the mounting block 13 by a second screw 9, and the flexible transmission structure 5 is threadedly connected with a third screw 10, and the third screw 10 passes through the flexible transmission structure 5 and abuts against the lower side of the mounting block 13, so as to push the mounting block 13 upward by the third screw 10, adjust the deformation degree of the double parallel plate flexible hinge 12 in the vertical direction, thereby adjusting the positive pressure of the contact between the driving block 4 and the top plate 1, and thus changing the magnitude of the friction force.

[0027] In order to facilitate the adjustment of the preload force of the piezoelectric ceramic component 14, in the present embodiment, preferably, the base 1 is threadedly connected with a fourth screw 11, and the side of the flexible transmission structure 5 away from the piezoelectric ceramic component 14 abuts against the fourth screw 11, so as to push the flexible transmission structure 5 toward the piezoelectric ceramic component 14 through the fourth screw 11, thereby adjusting the preload force of the piezoelectric ceramic component 14 to make the movement smooth and provide a certain load capacity.

[0028] See also Figure 5 The present invention also provides a control method for a precision motion compensation device using a stick-slip friction mechanism, comprising the following steps: S1, using the laser displacement sensor 7 to detect the current position of the boss 6 in real time, and calculating the error value between the current position and the set target position through the PID controller; S2. When the error value is greater than a preset threshold, the stick-slip actuator is controlled to drive the top plate 2 to move continuously in a maximum step length, and the maximum step length is determined by the performance of the selected stick-slip actuator; S3. When the error value is less than or equal to the preset threshold, the eddy current search algorithm is used to optimize and adjust the initial parameters of the PID controller to obtain the optimal parameters of the PID controller; S4. The PID controller outputs an electrical signal to the piezoelectric ceramic component 14 according to the optimal parameters. The piezoelectric ceramic component 14 generates a corresponding deformation according to the electrical signal. The flexible transmission structure 5 serves as a transmission mechanism to transmit the deformation of the piezoelectric ceramic component 14 to the driving block 4. The driving block 4 pushes the top plate 2 forward through static friction. When the piezoelectric ceramic component 14 reaches the maximum deformation corresponding to the electrical signal, the piezoelectric ceramic component 14 is controlled to retract quickly to the initial state. At the same time, the driving block 4 is driven to reset through the flexible transmission structure 5. Due to the existence of inertia, the top plate 2 cannot move synchronously with the driving block 4 in time, but remains in the original position. Relative sliding is formed between the contact surfaces of the driving block 4 and the top plate 2. At this time, the friction force exists in the form of dynamic friction. The above deformation process of the piezoelectric ceramic component 14 is repeated, and then the top plate 2 is pushed by the driving block 4 to perform continuous stepping movement with the optimal step length.

[0029] In order to further improve the control accuracy, in this embodiment, preferably, the following steps are further included after step S4: S5, determining whether the error value is less than or equal to a preset accuracy value, if so, stopping driving the stick-slip actuator, if not, returning to step S3; The purpose is to use the laser displacement sensor 7 to detect the current position of the boss 6 in real time after the top plate 2 is continuously stepped with the optimal step length, and calculate the error value between the current position and the set target position through the PID controller to determine whether the error value is less than or equal to the preset accuracy value. If so, stop driving the stick-slip actuator. If not, return to step S3 to re-adjust the optimal parameters of the PID controller. This cycle is repeated to make the error value less than or equal to the preset accuracy value, thereby improving the control accuracy and preventing the stick-slip actuator from being stopped when the error value is not less than or equal to the preset accuracy value, thereby improving reliability.

[0030] See also Figure 6 In order to improve the parameter optimization and setting effect of the PID controller, in this embodiment, preferably, in step S3, the eddy current search algorithm is used to set the initial parameters of the PID controller, and the specific steps for obtaining the optimal parameters of the PID controller are: S31, determining the initial parameters of the PID controller based on empirical rules, determining the number of eddy current search particles, the maximum number of iterations, and the upper and lower bounds of the d-dimensional search space according to the initial parameters, and setting the fitness function value of the eddy current center to infinity; S32. Calculate the eddy center and vortex radius , eddy center Calculation formula and eddy current radius The calculation formulas are expressed as follows:

[0031] ; in, is the upper bound of the d-dimensional search space, is the lower bound of the d-dimensional search space, , , is the inverse incomplete gamma function, is a parameter in the inverse incomplete gamma function, which takes the value 1; S33, draw a circle with the current eddy center as the center and the current eddy radius as the radius, use Gaussian distribution to sample within the circle and generate a candidate solution set consisting of multiple eddy search particles, the candidate solution set It is expressed as: ; in, Search particle number for eddy current, is the current iteration number; S34, calculate the fitness function values ​​of all eddy current search particles, and extract the minimum value from the fitness function values ​​of all eddy current search particles, and determine whether the minimum value is less than the fitness function value of the current eddy current center. If so, the eddy current search particle corresponding to the minimum value is used as the current eddy current center. It is expressed as: ; in, Search for particles for the eddy current corresponding to the minimum value; S35, determine whether the current number of iterations is equal to the maximum number of iterations, if so, use the current eddy center particle value as the optimal parameter of the PID controller , the optimal parameters It is expressed as: ; in, is the optimal proportionality coefficient, is the optimal integration coefficient, is the optimal differential coefficient Otherwise, the radius is adjusted and the process returns to step S33. The formula for adjusting the radius is expressed as: , ; in, is the maximum number of iterations, is the current iteration number, , is the radius of the tth iteration, , , is the incomplete gamma function The inverse function of is a parameter in the inverse incomplete gamma function; It is expressed as: .

[0032] In order to facilitate the acquisition of multiple candidate solutions, in this embodiment, preferably, in step S33, the formula for sampling within the circle using Gaussian distribution is expressed as: ; in, is the probability density function, which represents the random variable The probability of being selected, is a d×1 dimensional random variable, is the vortex center vector, is the covariance matrix, , is the d-dimensional identity matrix, for The determinant of for The inverse matrix of .

[0033] In order to prevent the candidate solutions from exceeding the boundary of the d-dimensional search space, in this embodiment, preferably, in step S33, the specific steps of sampling within the circle using Gaussian distribution and generating a candidate solution set consisting of multiple eddy current search particles are: S331, sampling within the circle using Gaussian distribution and generating a candidate solution set consisting of a plurality of eddy current search particles; S332, perform boundary constraint processing on each eddy current search particle in the candidate solution set. The boundary constraint processing formula of each eddy current search particle is expressed as: ; in, is the set of nearest solutions in the tth iteration The value of the kth eddy current search particle. When the value of the eddy current search particle is less than the lower bound When taking the lower bound When the value of the eddy current search particle is greater than the upper bound When taking the upper bound otherwise, keep the original value unchanged.

[0034] In order to conveniently measure the quality of each eddy current search particle, in this embodiment, preferably, in step S34, the specific steps of calculating the fitness function values ​​of all eddy current search particles are: S341, using each eddy current search particle as a parameter input of the PID controller, predicting the position of the boss 6 after executing h moves, S342, calculating the fitness function value of each eddy current search particle according to the preset boss 6 target position and the boss 6 predicted position, and the calculation formula of the fitness function value of each eddy current search particle is expressed as: ; in, is the fitness function value, To predict the position of boss 6 after h moves, For the target position of boss 6, the optimal eddy current search particle should minimize the fitness function value, so the quality of each eddy current search particle can be measured according to the fitness function value.

[0035] In order to facilitate and quickly perform preliminary tuning of the initial parameters of the PID controller, in this embodiment, preferably, the empirical rule is the Ziegler-Nichols empirical rule or the Chien-Hrones-Reswick empirical rule. The purpose is to perform preliminary tuning of the initial parameters of the PID controller by the Ziegler-Nichols empirical rule or the Chien-Hrones-Reswick empirical rule, improve adaptability, save time and cost of system modeling, and directly perform parameter tuning according to the actual process response, thereby improving work efficiency, and providing more appropriate initial parameter values, avoiding over-adjustment or improper parameter selection that may occur in manual adjustment, and effectively avoiding excessive oscillation or slow response of the system.

[0036] Finally, it should be noted that the above description is only a preferred example of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A precision motion compensation device using a stick-slip friction mechanism, comprising a base (1) and a top plate (2) arranged above the base (1), characterized in that: The invention also comprises a PID controller, wherein the top plate (2) and the base (1) are connected via two groups of cross roller guide rails (3), the middle part of the base (1) is connected with a stick-slip actuator, the stick-slip actuator comprises a driving block (4), a piezoelectric ceramic component (14) and a flexible transmission structure (5) abutting against the piezoelectric ceramic component (14), the driving block (4) is mounted on the top of the flexible transmission structure (5), and the upper side surface thereof abuts against the lower side surface of the top plate (2), the top of the top plate (2) is connected with a boss (6), one side of the boss (6) is provided with a laser displacement sensor (7), and the laser displacement sensor (7) and the piezoelectric ceramic component (14) are both electrically connected to the PID controller.

2. The precision motion compensation device using the stick-slip friction mechanism according to claim 1, characterized in that: Both sides of the base (1) are connected with first screws (8) via threads, and the two first screws (8) are respectively in contact with the opposite sides of the two sets of cross roller guide rails (3).

3. A control method for a precision motion compensation device using a stick-slip friction mechanism according to claim 1 or 2, characterized in that: The following steps are involved: S1, using a laser displacement sensor (7) to detect the current position of the boss (6) in real time, and calculating the error value between the current position and the set target position through a PID controller; S2, when the error value is greater than a preset threshold, controlling the stick-slip actuator to drive the top plate (2) to perform continuous stepping movement at a maximum step length; S3. When the error value is less than or equal to the preset threshold, the eddy current search algorithm is used to optimize and adjust the initial parameters of the PID controller to obtain the optimal parameters of the PID controller; S4, the PID controller outputs an electrical signal to the piezoelectric ceramic component (14) according to the optimal parameters, so that the stick-slip actuator drives the top plate (2) to perform continuous stepping movement at an optimal step length according to the current electrical signal.

4. The control method of the precision motion compensation device using the stick-slip friction mechanism according to claim 3, characterized in that: After step S4, the method further includes the following steps: S5. Determine whether the error value is less than or equal to the preset accuracy value. If so, stop driving the stick-slip actuator. If not, return to step S3.

5. The control method of the precision motion compensation device using the stick-slip friction mechanism according to claim 3, characterized in that: In step S3, the specific steps of using the eddy current search algorithm to adjust the initial parameters of the PID controller and obtain the optimal parameters of the PID controller are: S31, determining the initial parameters of the PID controller based on empirical rules, determining the number of eddy current search particles, the maximum number of iterations, and the upper and lower bounds of the d-dimensional search space according to the initial parameters, and setting the fitness function value of the eddy current center to infinity; S32. Calculate the eddy center and vortex radius , the vortex center Calculation formula and eddy current radius The calculation formulas are expressed as follows: ； in, is the upper bound of the d-dimensional search space, is the lower bound of the d-dimensional search space, , , is the inverse incomplete gamma function, is a parameter in the inverse incomplete gamma function, which takes the value 1; S33, draw a circle with the current eddy center as the center and the current eddy radius as the radius, use Gaussian distribution to sample within the circle and generate a candidate solution set consisting of multiple eddy search particles, the candidate solution set It is expressed as: ； in, Search particle number for eddy current, is the current iteration number; S34, calculate the fitness function values ​​of all eddy current search particles, and extract the minimum value from the fitness function values ​​of all eddy current search particles, and determine whether the minimum value is less than the fitness function value of the current eddy current center. If so, use the eddy current search particle corresponding to the minimum value as the current eddy current center. It is expressed as: ； in, Search for particles for the eddy current corresponding to the minimum value; S35, determine whether the current number of iterations is equal to the maximum number of iterations, if so, use the current eddy center particle value as the optimal parameter of the PID controller Otherwise, the radius is adjusted and the process returns to step S33. The formula for adjusting the radius is expressed as: ， ； in, is the maximum number of iterations, is the current iteration number, , is the radius of the tth iteration, , , is the inverse incomplete gamma function, is a parameter in the inverse incomplete gamma function.

6. The control method of the precision motion compensation device using the stick-slip friction mechanism according to claim 5, characterized in that: In step S33, the formula for sampling within a circle using Gaussian distribution is expressed as: ； in, is the probability density function, which represents the random variable The probability of being selected, is a d×1 dimensional random variable, is the vortex center vector, is the covariance matrix, , is the d-dimensional identity matrix, for The determinant of for The inverse matrix of .

7. The control method of a precision motion compensation device using a stick-slip friction mechanism according to claim 5, characterized in that: In step S33, the specific steps of sampling within a circle using Gaussian distribution and generating a candidate solution set consisting of a plurality of eddy current search particles are: S331, sampling within the circle using Gaussian distribution and generating a candidate solution set consisting of a plurality of eddy current search particles; S332, perform boundary constraint processing on each eddy current search particle in the candidate solution set, wherein the boundary constraint processing formula of each eddy current search particle is expressed as: ； in, is the set of nearest solutions in the tth iteration The value of the kth eddy current search particle. When the value of the eddy current search particle is less than the lower bound When taking the lower bound When the value of the eddy current search particle is greater than the upper bound When taking the upper bound otherwise, keep the original value unchanged.

8. The control method of a precision motion compensation device using a stick-slip friction mechanism according to claim 5, characterized in that: In step S34, the specific steps of calculating the fitness function values ​​of all eddy current search particles are: S341, using each eddy current search particle as a parameter input of the PID controller, predicting the position of the boss (6) after executing h moves, S342, calculating the fitness function value of each eddy current search particle according to the preset boss (6) target position and the boss (6) predicted position, wherein the fitness function value of each eddy current search particle is calculated as follows: ； in, is the fitness function value, To predict the position of boss (6) after h moves, is the target position of the boss (6).

9. The control method of a precision motion compensation device using a stick-slip friction mechanism according to claim 5, characterized in that: The empirical rule is the Ziegler-Nichols empirical rule or the Chien-Hrones-Reswick empirical rule.

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