A control method and control device of a sports table system and a sports table system

Abstract

The present invention discloses a control method, a control device and a motion platform system. The control method comprises: obtaining the actual position information of the gantry axis beam in the second direction and the actual rotation angle information in the third direction; determining the driving force resultant required by the gantry axis beam in the second direction according to the actual position information, and determining the first torque required by the gantry axis beam in the third direction according to the actual rotation angle information; and calculating the first driving force of the first motor and the second driving force of the second motor in combination with the driving force resultant and the first torque. The output of the first motor and the second motor are determined in combination with the driving force resultant and the first torque, so that the position of the gantry dual-drive structure in the RW direction can be controlled, thereby solving the problem of unbalanced torque of the gantry axis beam caused by the unbalanced output of the first motor and the second motor, and improving the positioning accuracy of the point of interest and the service life of the connector in the gantry dual-drive structure.

Description

Technical Field

[0001] Embodiments of the present invention relate to the field of precision manufacturing technology, and in particular to a control method and a control device of a motion stage system, and a motion stage system. Background Art

[0002] In the fields of semiconductor wafer inspection, laser processing, etc., there are high requirements for the positioning accuracy and repeatability of the servo motion platform. The gantry dual-drive structure is widely used in the mechanical structure design of high-precision motion equipment due to its advantages such as high combined positioning accuracy and high stability. It is generally used in the architecture design of the bottom axis, and can also improve the stability of the upper axis. In general equipment, the upper axis is a single-drive structure, and the bottom axis adopts a gantry dual-drive structure. The gantry dual-drive structure is generally composed of two motors, two grating encoders, and a gantry axis beam. The movement direction of the gantry axis beam is controlled by the joint output of the two motors.

[0003] However, due to installation errors, asynchronous motor drive, and mechanical dynamics differences, the motor output on both sides of the gantry axis beam is unbalanced, the drive efficiency is low, and torque is generated in the motion platform surface, causing the gantry axis beam to deflect around its axial symmetry axis. If this position deflection is not controlled, it will affect the positioning accuracy of the point of interest. At the same time, long-term unbalanced torque will affect the life of the connectors of the gantry dual-drive structure. Summary of the invention

[0004] Based on the above-mentioned defects of the prior art, the present invention provides a control method, a control device and a motion platform system for improving the positioning accuracy of points of interest and prolonging the service life of the connecting parts in the gantry dual-drive structure.

[0005] In a first aspect, an embodiment of the present invention provides a control method for a motion platform system, wherein the motion platform system includes a gantry dual-drive structure, the gantry dual-drive structure includes a gantry axis beam, a first motor and a second motor, when the gantry dual-drive structure is in a mechanical balance posture, the gantry axis beam extends along a first direction; the first motor and the second motor are respectively arranged on both sides of the extension direction of the gantry axis beam, and the first motor and the second motor drive the gantry axis beam to move along a second direction; the first direction is perpendicular to the second direction;

[0006] The control method of the motion table system includes:

[0007] Acquire the actual position information of the gantry axis crossbeam in the second direction and the actual rotation angle information in the third direction; the third direction rotates around the virtual symmetry axis of the gantry axis crossbeam, and the virtual symmetry axis is perpendicular to the first direction and the second direction;

[0008] Determine the driving force resultant required by the gantry axis crossbeam in the second direction according to the actual position information, and determine the first torque required by the gantry axis crossbeam in the third direction according to the actual rotation angle information;

[0009] A first driving force of the first motor and a second driving force of the second motor are calculated by combining the driving force resultant and the first torque.

[0010] In a second aspect, an embodiment of the present invention provides a control device for a sports table system, which is applicable to a control method for a sports table system provided by any embodiment of the present invention;

[0011] The control device of the motion table system includes:

[0012] An actual motion information acquisition module is used to acquire actual position information of the gantry axis crossbeam in the second direction and actual rotation angle information in the third direction; the third direction rotates around a virtual symmetry axis of the gantry axis crossbeam, and the virtual symmetry axis is perpendicular to the first direction and the second direction;

[0013] A driving force resultant and first torque determination module, used to determine the driving force resultant required by the gantry axis crossbeam in the second direction according to the actual position information, and to determine the first torque required by the gantry axis crossbeam in the third direction according to the actual rotation angle information;

[0014] The motor driving force decoupling module is used to calculate the first driving force of the first motor and the second driving force of the second motor by combining the driving force resultant and the first torque.

[0015] In a third aspect, an embodiment of the present invention provides a motion platform system, including a gantry dual-drive structure and a controller, wherein the controller is electrically connected to the gantry dual-drive structure;

[0016] The gantry dual-drive structure includes a gantry axis crossbeam, a first motor and a second motor. When the gantry dual-drive structure is in a mechanically balanced posture, the gantry axis crossbeam extends along a first direction; the first motor and the second motor are respectively arranged on both sides of the extension direction of the gantry axis crossbeam, and the first motor and the second motor drive the gantry axis crossbeam to move along a second direction, and the first direction is perpendicular to the second direction;

[0017] The controller is used to execute the control method of the sports table system provided by any embodiment of the present invention.

[0018] The control method of the motion platform system provided by the embodiment of the present invention first obtains the actual position information of the gantry axis beam in the second direction and the actual rotation angle information in the third direction; secondly, the driving force resultant required by the gantry axis beam in the second direction is determined according to the actual position information, and the first torque required by the gantry axis beam in the third direction is determined according to the actual rotation angle information; then, the first driving force of the first motor and the second driving force of the second motor are calculated in combination with the driving force resultant and the first torque. Taking into account the actual rotation angle of the gantry axis beam in the third direction, the output of the first motor and the output of the second motor are determined in combination with the driving force resultant and the first torque, so that the position of the gantry dual-drive structure in the RW direction can be controlled, thereby solving the problem of unbalanced torque of the gantry axis beam caused by the imbalance of the output of the first motor and the second motor, and improving the positioning accuracy of the point of interest and the service life of the connector in the gantry dual-drive structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A front view of a sports table system provided by an embodiment of the present invention;

[0020] Figure 2 A top view of another sports table system provided by an embodiment of the present invention;

[0021] Figure 3 A flow chart of a control method of a sports platform system provided by an embodiment of the present invention;

[0022] Figure 4 A schematic diagram of the movement direction of a gantry dual-drive structure provided in an embodiment of the present invention;

[0023] Figure 5 A control logic block diagram of a controller provided by an embodiment of the present invention;

[0024] Figure 6 A schematic diagram of the output direction of a sports table system provided by an embodiment of the present invention;

[0025] Figure 7 A control logic block diagram for compensating for mass center offset and single-axis output is provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0027] It should be noted that the words “having”, “including”, “comprising”, etc. described in this application are all open-ended meanings, that is, when describing that a module “has”, “including”, or “comprising” a first element, a second element, and / or a third element, it means that the module includes other elements in addition to the first element, the second element, and / or the third element. In addition, ordinal numbers such as “first”, “second”, and “third” in this application are not intended to limit a specific order, but are only used to distinguish various parts.

[0028] The control method of the motion platform system provided by the embodiment of the present invention is applicable to the motion platform system adopting the gantry dual-drive structure in the prior art. Figure 1 A front view of a sports table system provided by an embodiment of the present invention, Figure 2 A top view of another sports table system provided by an embodiment of the present invention, Figure 1 shows a front view of the motion table system, Figure 2 A top view of the motion table system is shown, referring to Figure 1 and Figure 2 The motion platform system includes a gantry dual-drive structure, which includes a gantry axis beam 10, a first motor 11 and a second motor 12. When the gantry dual-drive structure is in a mechanical balance posture, the gantry axis beam 10 extends along a first direction X; the first motor 11 and the second motor 12 are respectively arranged on both sides of the extension direction of the gantry axis beam 10, and the first motor 11 and the second motor 12 drive the gantry axis beam 10 to move along a second direction Y; the first direction X is perpendicular to the second direction Y.

[0029] like Figure 1 and Figure 2 As shown, the gantry drive structure can be installed on the base 20 of the motion platform system, and the mechanical balance posture of the gantry dual-drive structure can also be understood as the state of the gantry axis crossbeam 10 in the initial state. Figure 2 The figure shows that the gantry dual-drive structure is in a mechanically balanced posture. Figure 2 In the orientation shown in , the horizontal direction is the first direction X, the vertical direction is the second direction Y, and the plane determined by the first direction X and the second direction Y is the plane where the base 20 is located. The first motor 11 and the second motor 12 are respectively arranged on both sides of the gantry axis crossbeam 10, and the first motor 11 and the second motor 12 jointly drive the gantry axis crossbeam 10 to move along the second direction Y. The sample stage 30 is installed on the side of the gantry axis crossbeam 10 away from the base 20, and the sample (such as a wafer) is placed on the sample stage 30, and the position of the sample stage 30 in the second direction Y is adjusted by the first motor 11 and the second motor 12.

[0030] The motion stage system also includes a grating encoder component, which is used to detect the position of the gantry axis crossbeam 10 (sample stage 30) to ensure that the sample stage 30 moves to the target position. The grating encoder is a measurement feedback device that works based on the optical principle of the grating. The grating encoder is often used in the closed-loop servo system of CNC machine tools and can be used to detect linear displacement or angular displacement. The measurement output signal is a digital pulse with the characteristics of a large detection range, high detection accuracy, and fast response speed.

[0031] like Figure 1 and Figure 2 As shown, in the embodiment of the present invention, the motion stage system includes a first grating encoder 13 and a second grating encoder 14, and the first grating encoder 13 and the second grating encoder 14 components are respectively located on both sides of the extension direction of the gantry axis cross beam 10. The first grating encoder 13 and the second grating encoder 14 are electrically connected to a controller (not shown in the figure) of the motion stage system, and the controller determines the position information of the gantry axis cross beam 10 according to the grating scale readings of the first grating encoder 13 and the second grating encoder 14.

[0032] The specific configuration of the gantry drive structure and the grating encoder assembly is not limited, and any existing gantry drive structure and grating encoder assembly are within the scope of the technical solution protected by the embodiment of the present invention. Figure 1 and Figure 2 , the stators of the first motor 11 and the second motor 12 and the grating scales of the first grating encoder 13 and the second grating encoder 14 can be installed on the marble base 20 on both sides of the gantry axis cross beam 10, and the movers of the first motor 11 and the second motor 12 and the readers of the first grating encoder 13 and the second grating encoder 14 can be fixed on both sides of the gantry axis cross beam 10. The side connected to the gantry axis cross beam 10 and the first motor 11 can be defined as the first side, and the side connected to the second motor 12 can be defined as the second side. When the first motor 11 and the second motor 12 are driven asynchronously, there will be a difference between the driving force of the first motor 11 on the first side and the driving force of the second motor 12 on the second side, that is, the output of the first motor and the output of the second motor are unbalanced, thereby causing the gantry axis cross beam 10 to rotate in the third direction RW. In order to avoid uncontrollable rotation of the gantry axis cross beam 10 in the third direction RW, an embodiment of the present invention proposes a solution for decoupling control of the actual rotation angle information of the gantry axis cross beam 10. The control method of the motion platform system proposed in the embodiment of the present invention is applicable to the motion platform system with a gantry dual-drive structure. The control method can be executed by a control device of the motion platform system, and the control device can be a controller of the motion platform system. Figure 3 A flowchart of a control method of a sports platform system provided by an embodiment of the present invention can be referred to Figure 3 , the control method of the motion table system comprises the following steps:

[0033] S110, obtaining actual position information of the gantry axis crossbeam in the second direction and actual rotation angle information in the third direction.

[0034] Among them, reference Figure 1 and Figure 2 , the third direction RW rotates around the virtual symmetry axis 101 of the gantry axis beam 10, and the virtual symmetry axis 101 is perpendicular to the first direction X and the second direction Y. The virtual symmetry axis 101 of the gantry axis beam 10 refers to a virtual axis that is perpendicular to the gantry axis beam 10 (or the plane where the base is located) and coincides with the center of the gantry axis beam 10. The extension direction of the virtual symmetry axis 101 is Figure 1 In the Z direction. Generally, the gantry axis cross beam 10 is of a regular shape, and its center can also be regarded as the center of mass of the gantry axis cross beam 10. The first grating encoder 13 and the second grating encoder 14 can be used to detect the actual position of the gantry axis cross beam 10 in the second direction Y and the third direction RW in real time. The position of the gantry axis cross beam 10 in the second direction Y can refer to the moving distance of the gantry axis cross beam 10 in the second direction Y, and the position in the second direction Y can refer to its rotation angle in the third direction RW, that is, the angle of rotation around the Z direction.

[0035] The specific method of using the first grating encoder and the second grating encoder to determine the actual position information and the actual rotation angle signal is not limited and can be implemented by any existing technology.

[0036] For example, in some embodiments, the actual location information is P G , the actual rotation angle information is P RW , P G It can be calculated using the following formula (1): P RW It can be calculated using the following formula (2):

[0037] ; Formula (1);

[0038] ; Formula (2);

[0039] P En1 is the grating scale reading of the first grating encoder, P En2 is the grating scale reading of the second grating encoder, L En is the distance between the first grating encoder and the second grating encoder in the extension direction of the gantry axis crossbeam.

[0040] Based on the grating scale readings of the first grating encoder and the second grating encoder, the actual position information of the gantry axis crossbeam in the second direction and the actual rotation angle information in the third direction can be determined according to the above formulas (1) and (2).

[0041] S120, determining the driving force resultant required by the gantry axis crossbeam in the second direction according to the actual position information, and determining the first torque required by the gantry axis crossbeam in the third direction according to the actual rotation angle information.

[0042] Figure 4 A schematic diagram of the movement direction of a gantry dual-drive structure provided in an embodiment of the present invention, referring to Figure 4 The third direction RW can be regarded as the direction in which the gantry axis cross beam 10 rotates from the first direction X to the second direction Y. It can be understood that when the gantry axis cross beam 10 is controlled to move upward along the second direction Y, the driving force along the second direction Y received by the gantry axis cross beam 10 drives it to move upward; the torque in the third direction RW received by the gantry axis cross beam 10 drives it to rotate in the third direction RW.

[0043] In this embodiment, the controller may include a driving force resultant and a first torque determination module, which can determine the driving force resultant required by the gantry axis beam in the second direction according to the actual position information of the gantry axis beam in the second direction, and determine the first torque required by the gantry axis beam in the third direction according to the actual rotation angle information of the gantry axis beam in the third direction. The driving force resultant is the driving force that needs to be applied to the gantry axis beam to control the gantry axis beam to move to the target position. The first torque is the torque that needs to be applied to the gantry axis beam to control the gantry axis beam to rotate to the target angle. Generally, the rotation of the gantry axis beam is an undesirable rotation. For the air-floating guide rail, the target angle can be regarded as 0 degrees. For the mechanical guide rail, the target angle can refer to the angle when the gantry axis beam is perpendicular to the guide rail. At the target angle, the gantry dual-drive structure is in a mechanical balance posture.

[0044] S130 , calculating a first driving force of the first motor and a second driving force of the second motor by combining the driving force resultant and the first torque.

[0045] Since the first motor and the second motor jointly drive the gantry axis beam to move, the movement of the gantry axis beam in the second direction and the rotation in the third direction are the result of the joint drive of the first motor and the second motor. Therefore, in the present invention, after determining the driving force resultant and the first torque required for the gantry axis beam to move from the current position to the target position, the first driving force that the first motor still needs to provide and the second driving force that the second motor still needs to provide can be determined in combination with the driving force resultant and the first torque. Then, the motor control module controls the first motor to provide the first driving force and the second motor to provide the second driving force, respectively, to drive the gantry axis beam to move toward the target position. In the process of driving the gantry axis beam to move, the controller continuously obtains the actual horizontal position of the gantry axis and executes the above control logic to ensure the accuracy of the position control of the gantry axis beam and to ensure that the position in the RW direction is controllable.

[0046] Compared with the prior art, which only determines the output of the first motor and the second motor according to the driving force received by the gantry axis beam in the second direction, the solution in the present invention takes into account the actual rotation angle of the gantry axis beam in the third direction, and determines the output of the first motor (i.e., the first driving force) and the output of the second motor (i.e., the second driving force) in combination with the driving force resultant and the first torque, so that the position of the gantry dual-drive structure in the RW direction can be controlled, thereby solving the problem of unbalanced torque on the gantry axis beam caused by the imbalance of the output of the first motor and the second motor. It can improve the positioning accuracy of the point of interest, solve the problem of the positioning repeatability of the motion platform caused by the repeatability in the RW direction, and improve the service life of the connector in the gantry dual-drive structure.

[0047] For example, Figure 5 A control logic block diagram of a controller provided by an embodiment of the present invention, such as Figure 5 As shown, the controller may include an actual motion information acquisition module 100, a driving force resultant force and a first torque determination module 200, a motor driving force decoupling module 300 and a motor control module 400. The actual motion information acquisition module 100 determines the actual position information of the gantry axis crossbeam in the second direction based on the first grating encoder and the second grating encoder. P G And the actual rotation angle information in the third direction P RW The driving force resultant and first torque determination module 200 includes a second direction control module 201 and a third direction control module 202. The actual position information of the gantry axis crossbeam in the second direction P G It can be used as the input of the second direction control module 201, the driving force F G is the output of the second direction control module 201, the actual position information P GAfter the determination, the second direction control module 201 can calculate the driving force required for the gantry axis beam to move from the actual position (i.e., the current position) to the target position. F G And output. The actual rotation angle information of the gantry axis beam in the third direction P RW Can be used as an input to the third direction control module 202, the first torque T RWFB is the output of the third direction control module 202, the actual rotation angle information P RW After the determination, the third direction control module 202 can calculate the first torque required for the gantry axis beam to move from the actual rotation angle (i.e., the current rotation angle) to the target angle. T RWFB The internal control logic of the second direction control module 201 and the third direction control module 202 is the same as the input and output logic of the position controller in the prior art, and will not be described in detail here. F G and first torque T RWFB As the input of the motor driving force decoupling module 300, the motor driving force decoupling module 300 converts the driving force into F G and first torque T RWFB Transformed into the first driving force F 1 and the second driving force F 2 And output. The first driving force F 1 and the second driving force F 2 Input motor control module 400, the motor control module 400 may include a first motor control submodule and a second motor control submodule ( Figure 5 The first motor control submodule is used to output a control signal to the first motor, and the second motor control submodule is used to output a control signal to the second motor. The first motor control submodule controls the first motor to provide a first driving force F 1 The second motor control submodule controls the second motor to provide a second driving force F 2 , to drive the gantry axis crossbeam to move. During the movement of the gantry axis crossbeam, the first grating encoder and the second grating encoder continuously feed back position detection data to the actual motion information acquisition module 100 P En1 and P En2, the controller repeatedly executes the above control logic until the gantry axis beam moves to the target position.

[0048] The control method of the motion platform system provided by the embodiment of the present invention first obtains the actual position information of the gantry axis beam in the second direction and the actual rotation angle information in the third direction; the third direction rotates around the virtual symmetry axis of the gantry axis beam, and the virtual symmetry axis is perpendicular to the first direction and the second direction; secondly, the driving force resultant required by the gantry axis beam in the second direction is determined according to the actual position information, and the first torque required by the gantry axis beam in the third direction is determined according to the actual rotation angle information; then the first driving force of the first motor and the second driving force of the second motor are calculated by combining the driving force resultant and the first torque. Taking into account the actual rotation angle of the gantry axis beam in the third direction, the output of the first motor and the output of the second motor are determined by combining the driving force resultant and the first torque, so that the gantry dual-drive structure can be controlled in the RW direction, thereby solving the problem of unbalanced torque of the gantry axis beam caused by the unbalanced output of the first motor and the second motor, and improving the positioning accuracy of the point of interest. At the same time, the problem of the repeatability of the motion platform positioning caused by the repeatability of the RW direction is solved, and the service life of the connector in the gantry dual-drive structure is improved.

[0049] Optionally, in a possible embodiment, the above (S120) may be refined as follows: determining the driving force resultant according to the difference between the actual position information and the target reference position information, and determining the first torque according to the difference between the actual rotation angle information and the target reference rotation angle information.

[0050] You can continue to refer to Figure 5 The target reference position indicates the reference position of the gantry axis beam in the second direction, that is, the final target position of the gantry axis beam; the target reference rotation angle indicates the reference position of the gantry axis beam in the third direction, that is, the target rotation angle of the gantry axis beam. Actual position information P G and target reference position information P GRef The difference between the two values ​​is used as the input of the second direction control module 201, and the second direction control module 201 can calculate the driving force required for the gantry axis beam to move to the target position. F G . Actual rotation angle information P RW and target reference rotation angle information P RwRef The third direction control module 202 can calculate the first torque required for the gantry axis crossbeam to rotate to the target rotation angle according to the difference between the two. T RWFB .

[0051] Optionally, in a possible embodiment, the first driving force is F 1 , the second driving force is F 2 , F 1 and F 2 The following formulas (3) and (4) are used for calculation;

[0052] ; Formula (3);

[0053] ; Formula (4);

[0054] L 1 is the distance between the first motor output point and the initial center of mass of the gantry axis in the extension direction of the gantry axis crossbeam, L 2 is the distance between the second motor output point and the initial center of mass of the gantry axis in the extension direction of the gantry axis crossbeam, F G As the driving force, T RWFB is the first torque. L 1 and L 2 Both are scalar and positive.

[0055] like Figure 4 As shown, the initial mass center G1 of the gantry axis is the mass center of the gantry axis cross beam 10 when it is at the gantry axis logic zero position. The gantry axis logic zero position is the initial position of the gantry axis cross beam 10. At the initial position, the mass center G1 of the gantry axis cross beam 10 is at Figure 4 It can be understood that the first driving force F 1 and the second driving force F 2 The resultant force along the second direction is the driving force resultant force F G ,Right now F G = F 1 + F 2 , regard the gantry axis beam as a lever. According to the lever law, F 1 × L 1 - F 2 × L 2 = T RW, these two formulas can be used to obtain the above formulas (3) and (4). F G and first torque T RWFB After the determination, the output of the first motor and the output of the second motor can be calculated according to formula (3) and formula (4).

[0056] Optional, you can continue to refer to Figure 1 and Figure 2 , the motion table system also includes a single-axis driving structure, a third grating encoder 42 and a fourth grating encoder 43. The single-axis driving structure includes a single-axis shaft body 40 and a third motor 41. The single-axis shaft body 40 and the third motor 41 are located on the gantry axis beam 10. The third motor 41 is connected to the single-axis shaft body 40 and is used to drive the single-axis shaft body 40 to move along the extension direction of the gantry axis beam 10; the third grating encoder 42 and the fourth grating encoder 43 are respectively located on both sides of the single-axis shaft body 40 along the second direction Y, and the third grating encoder 42 and the fourth grating encoder 43 are used together to detect the position information of the single-axis shaft body 40. Before the above (S130), it also includes: calculating the feedforward compensation torque of the gantry axis beam in the third direction according to the third driving force of the third motor; calculating the second torque of the gantry axis beam in the third direction in combination with the first torque and the feedforward compensation torque: (S130) can be refined as: calculating the first driving force of the first motor and the second driving force of the second motor in combination with the driving force resultant force and the second torque; wherein the feedforward compensation torque is T RWFF , the second torque is T RW ,

[0057] ; Formula (5);

[0058] ; Formula (6);

[0059] h is the distance between the output point of the third motor and the mass center of the single shaft in the second direction, F S is the third driving force of the third motor, T RWFB is the first torque.

[0060] like Figure 1 and Figure 2As shown, the single-axis shaft body 40 is installed on the gantry axis cross beam 10, and the gantry axis cross beam 10 can be used as the motion axis of the single-axis driving structure. The third motor 41 is connected to the single-axis shaft body 40, and the third motor 41 drives the single-axis shaft body 40 to move back and forth along the extension direction of the gantry axis cross beam 10. The sample stage 30 is installed on the side of the single-axis shaft body 40 away from the gantry axis cross beam 10, and the sample stage 30 is driven by the third motor 41 to adjust the position of the sample stage 30 in the first direction X.

[0061] Among them, continue to refer to Figure 1 and Figure 2 The single-axis drive structure may include a third grating encoder 42 and a fourth grating encoder 43, and the third grating encoder 42 and the fourth grating encoder 43 are respectively close to both sides of the single-axis shaft body 40 along the second direction Y. Exemplarily, the grating scales of the third grating encoder 42 and the fourth grating encoder 43 may be distributed on both sides of the gantry axis crossbeam 10 along the second direction Y (i.e. Figure 2 The stator of the third motor 41 is located in the middle of the gantry axis cross beam 10, and the readers of the third grating encoder 42 and the fourth grating encoder 43 are fixed to the two sides of the single-axis shaft body 40 along the second direction Y by connecting members. The third grating encoder 42 and the fourth grating encoder 43 are connected to the controller ( Figure 1 and Figure 2 The controller determines the position information of the single-axis drive structure according to the grating scale readings of the third grating encoder 42 and the fourth grating encoder 43. The position information of the single-axis drive structure includes the position information of the single-axis shaft body 40 in the extension direction of the gantry axis cross beam 10 and the rotation angle information in the third direction RW.

[0062] Figure 6 A schematic diagram of the output direction of a sports table system provided by an embodiment of the present invention, referring to Figure 6 , due to factors such as equipment installation errors or mechanical structure design, the single-axis shaft body mass center G2 and the third motor output point f3 may not coincide in the second direction Y. When the single-axis shaft body mass center G2 and the third motor output point f3 do not coincide, the rotational torque of the single-axis shaft body 40 may be transmitted to the gantry axis crossbeam 10, causing the gantry axis crossbeam 10 to have crosstalk of the single-axis shaft body torque. If the driving force is calculated only based on the first torque, there will be a tracking error related to the driving force form of the single-axis motor (i.e., the third motor) in the third direction RW.

[0063] Based on this, this embodiment proposes a torque compensation scheme of feedforward plus feedback, and the feedback is the first torque of the gantry axis beam determined according to the actual rotation angle information. T RWFB Feedforward refers to the calculation of the feedforward compensation torque of the gantry axis crossbeam based on the output of the third motor. T RWFF , the feedforward compensation torqueT RWFF It can also be understood as the actual torque of the uniaxial shaft in the second direction during the movement of the sample stage.

[0064] Among them, continue to refer to Figure 6 , feedforward compensation torque T RWFF The above formula (5) can be used for calculation, where the distance between the third motor output point f3 and the single-axis shaft body mass center G2 in the second direction Y is h is a vector, when the mass center G2 of the single-axis body is in the positive direction of the second direction Y relative to the output point f3 of the third motor, h When the centroid G2 of the single-axis body and the output point f3 of the third motor do not coincide in the second direction Y, and the distance between the output point f3 of the third motor and the centroid G2 of the single-axis body in the second direction Y is h and the third driving force F S When it is not 0, a torque crosstalk in the third direction RW will be generated on the gantry axis crossbeam 10. The crosstalk torque is the product of the force and the lever arm, that is, F S × h At this time, in the third direction RW, you need to output - F S × h Torque (i.e. feedforward compensation torque T RWFF ) to balance this disturbance.

[0065] Therefore, in this embodiment, the feedforward compensation torque can be calculated according to formula (6): T RWFF and first torque T RWFB The sum of the values ​​is taken as the second torque T RW Output, thereby offsetting the influence of the actual torque of the single-axis shaft body on the torque of the gantry axis crossbeam in the third direction, improving the positioning accuracy and setting speed of the system. It can be understood that when the influence of the actual torque of the single-axis shaft body on the torque crosstalk of the gantry axis crossbeam is not considered, the second torque T RW With the first torque T RWFB equal.

[0066] When the torque compensation scheme of feedforward plus feedback is adopted, the above formulas (3) and (4) are refined as follows:

[0067] ; Formula (7);

[0068] ; Formula (8);

[0069] For example, Figure 7 A control logic block diagram of compensating mass center offset and single-axis output provided by an embodiment of the present invention, Figure 7 The embodiment shown in the above Figure 5 The embodiment shown is further refined. Figure 7 In the illustrated embodiment, the third direction control module 202 can be subdivided into a feedforward control submodule 2021 and a feedback control submodule 2022. F S The distance between the third motor output point f3 and the single-axis body mass center G2 in the second direction Y h It can be used as the input of the feedforward control submodule 2021 to feedforward compensate the torque T RWFF As the output of the feedforward control submodule 2021; the actual rotation angle information of the gantry axis crossbeam 10 P RW is the input of the feedback control submodule 2022, the first torque T RWFB is the output of the feedback control submodule 2022, the feedforward compensation torque T RWFF and first torque T RWFB The sum is used as the final output of the third direction control module 202 (i.e., the second torque T RW ).

[0070] Optionally, the motor control module may further include a third motor control submodule, which is used to output a control signal to the third motor, and the third driving force may be fed back by the third motor control submodule.

[0071] The distance between the output point of the third motor and the mass center of the single shaft in the second direction in the above formula (5) is h , which can be determined during the debugging stage of the motion table system. Exemplarily, in some embodiments, the control method also includes: during the system debugging stage, the single-axis shaft body servo is in the single-axis logic zero position, and the gantry axis beam is controlled to move along the second direction, and the first arm length and the second arm length of the gantry axis beam are identified with the center of mass of the gantry axis beam as the axis center; the single-axis logic zero position is the initial position of the single-axis shaft body; based on the first arm length and the second arm length, the single-axis shaft body is moved to the edge position of the gantry axis beam along the first direction, and the gantry axis beam is controlled to move along the second direction to identify the single-axis mass ratio; based on the first arm length, the second arm length and the single-axis mass ratio, the gantry axis beam servo is controlled to be in the gantry axis logic zero position, and the single-axis shaft body is controlled to move along the extension direction of the gantry axis beam to identify the distance between the third motor output point and the center of mass of the single-axis shaft body in the second direction. h ; The logical zero position of the gantry axis is the initial position of the gantry axis crossbeam.

[0072] Specifically, the single-axis logic zero position is the initial position of the single-axis body. At the initial position, the center of mass of the single-axis body is at Figure 4 The origin of the coordinate axis shown. The steps for determining parameters during the system debugging phase are as follows:

[0073] Step 1: The single-axis axis servo is in the single-axis logic zero position, and the gantry axis beam is controlled to move with large acceleration along the second direction. During the movement of the gantry axis beam, the first arm length is identified according to the principle of minimum position error in the third direction. L 1 and the second arm length L 2 , and the identified parameters L 1 and L 2 Write to system configuration;

[0074] Step 2: Based on the identification in the first step L 1 and L 2 , the single-axis shaft body servo is at the edge of the gantry axis beam, and controls the gantry axis beam to accelerate along the second direction. During the movement of the gantry axis beam, according to the principle of minimum position error in the third direction, the single-axis mass ratio is identified. K m , and the identified parameters K m Write to system configuration;

[0075] Step 3: Based on the identification in Steps 1 and 2 L 1 , L 2 and K m , the gantry axis crossbeam servo is in the gantry axis logical zero position, and controls the single axis body to move with large acceleration along the extension direction of the gantry axis crossbeam (i.e. the first direction). During the movement of the single axis body, according to the principle of minimum position error in the third direction, identify the distance between the output point of the third motor and the center of mass of the single axis body in the second direction. h , and write the identified parameters into the system configuration. L 1 , L 2 、K m and h Written into the system configuration as configuration parameters of the algorithm in the control logic.

[0076] The specific identification method of the above configuration parameters can be implemented by using any existing technology, and the embodiment of the present invention does not elaborate on it or limit it.

[0077] Optionally, in a possible embodiment, before (calculating the first driving force of the first motor and the second driving force of the second motor by combining the driving force resultant and the second torque) in the above embodiment, it may also include: determining the center of mass offset distance between the actual center of mass of the gantry axis and the initial center of mass of the gantry axis in the first direction; the initial center of mass of the gantry axis is the center of mass of the gantry axis crossbeam when the gantry axis is in the logical zero position of the gantry axis; (calculating the first driving force of the first motor and the second driving force of the second motor by combining the driving force resultant and the second torque) can be further refined as: calculating the first driving force of the first motor and the second driving force of the second motor by combining the center of mass offset distance, the driving force resultant and the second torque.

[0078] The inventors found that when the gantry axis cross beam is driven by the motors on both sides, the displacement of the center of mass of the gantry axis cross beam will generate torque disturbance in the third direction. Based on this, this embodiment proposes that the distribution algorithm of the driving force of the first motor and the second motor can be designed according to the change of the center of mass of the gantry axis cross beam.

[0079] Specifically, in determining the driving force F G and the second torque T RW After that, you can first determine the mass center offset distance between the actual mass center of the gantry axis and the initial mass center of the gantry axis. The initial mass center of the gantry axis refers to the mass center when the gantry axis crossbeam servo is in the logical zero position of the gantry axis, and the actual mass center of the gantry axis refers to the actual mass center of the gantry axis crossbeam during the movement of the sample stage. Then, you can combine the mass center offset distance, the driving force resultant force, and the F G and the second torque T RW Calculate the first driving force of the first motor F 1 and the second driving force of the second motor F 2 , or it can be understood that the above formulas (7) and (8) are corrected according to the mass center offset distance, so as to obtain the first driving force after compensating the mass center offset of the gantry axis crossbeam F 1 and the second driving force F 2 , further improving the system positioning accuracy.

[0080] For further reference, Figure 2 and Figure 6 As described above, the single-axis shaft body 40 is located on the gantry shaft beam 10, and the support force of the gantry shaft beam 10 on the single-axis shaft body 40 balances the gravity of the single-axis shaft body 40. Therefore, the center of mass of the gantry shaft beam 10 will move with the change of the position of the single-axis shaft body 40. As an optional embodiment, the center of mass offset distance of the gantry shaft beam 10 is ∆ LGG ,∆ L GG Calculated using formula (9);

[0081] ; Formula (9);

[0082] K m The single-axis mass ratio is obtained by identification during the system debugging phase. P S is the actual position of the uniaxial shaft body 40 in the first direction X; the first driving force is F 1 , the second driving force is F 2 , the above formula (7) can be corrected to formula (10), and formula (8) can be corrected to formula (11);

[0083] ; Formula (10);

[0084] ; Formula (11);

[0085] L 1 is the distance between the first motor output point and the initial center of mass of the gantry axis in the extension direction of the gantry axis crossbeam, L 2 is the distance between the second motor output point and the initial center of mass of the gantry axis in the extension direction of the gantry axis crossbeam, F G The driving force is combined.

[0086] Specifically, the uniaxial mass ratio K m =( m x ) / ( m x ＋m y ), m x is the mass of the uniaxial shaft, m y is the mass of the gantry axis beam. As mentioned above, the mass ratio of a single axis is K m Identified and written into the system configuration during the system adjustment phase. The actual position of the single-axis axis in the first direction P S Can be determined based on the third grating encoder and the fourth grating encoder. Single axis quality ratio K m and the actual position of the single-axis body in the first direction P SThe product of is the mass center offset distance ∆ of the gantry axis beam L GG .

[0087] Furthermore, the centroid offset distance ∆ L GG Influence on the first arm length of the gantry axis beam L 1 and the second arm length L 2 Determination of the centroid offset distance ∆ L GG After determination, the first driving force can be calculated according to the above formula (10) and formula (11): F 1 and the second driving force F 2 Through the above solution, the position error in the third direction caused by the position change of the single-axis shaft body is compensated, ensuring the first driving force F 1 and the second driving force F 2 The accuracy of the output increases the system tuning speed.

[0088] You can continue to refer to Figure 7 , offset the center of mass of the gantry axis beam by a distance ∆ L GG Taking into account the actual position of the uniaxial axis in the first direction P S It can also be used as an input of the motor driving force decoupling module 300, which combines the actual position of the single-axis shaft in the first direction P S First driving force F 1 and the second driving force F 2 Output.

[0089] Based on the same concept, an embodiment of the present invention also provides a control device for a sports table system, which can be used to control the sports table system provided by an embodiment of the present invention, that is, to execute the control method for the sports table system provided by any embodiment of the present invention. The control device can be implemented by software and / or hardware, and is generally integrated into the sports table system in the form of a controller. Figure 5 , the control device of the motion table system includes:

[0090] The actual motion information acquisition module 100 is used to acquire the actual position information of the gantry axis crossbeam in the second direction and the actual rotation angle information in the third direction; the third direction rotates around the virtual symmetry axis of the gantry axis crossbeam, and the virtual symmetry axis is perpendicular to the first direction and the second direction;

[0091] A driving force resultant and first torque determination module 200, for determining the driving force resultant required by the gantry axis crossbeam in the second direction according to the actual position information, and determining the first torque required by the gantry axis crossbeam in the third direction according to the actual rotation angle information;

[0092] The motor driving force decoupling module 300 is used to calculate the first driving force of the first motor and the second driving force of the second motor by combining the driving force resultant and the first torque.

[0093] Optionally, the control device of the sports table system may further include a motor control module 400, and the motor control module 400 is used to output control information to the first motor and the second motor to control the first motor and the second motor to work according to the control instruction.

[0094] The control device of the motion platform system provided by the embodiment of the present invention takes into account the actual rotation angle of the gantry axis beam in the third direction, and determines the output of the first motor and the second motor in combination with the driving force resultant and the first torque, so that the position of the gantry dual-drive structure in the RW direction can be controlled, thereby solving the problem of unbalanced torque on the gantry axis beam caused by the imbalance of the output of the first motor and the second motor, which can improve the positioning accuracy of the point of interest and increase the service life of the connecting parts in the gantry dual-drive structure.

[0095] The control device of the sports table system provided in the embodiment of the present invention also includes all the technical features and corresponding beneficial effects of the control method of the sports table system provided in any embodiment of the present invention, which will not be repeated here.

[0096] The embodiment of the present invention also provides a sports table system. The structure of the sports table system can be referred to Figure 1 and Figure 2 As well as the description of the corresponding embodiments, the motion platform system includes a gantry dual-drive structure and a controller, and the controller is electrically connected to the gantry dual-drive structure; the gantry dual-drive structure includes a gantry axis beam 10, a first motor 11 and a second motor 12, and when the gantry dual-drive structure is in a mechanically balanced posture, the gantry axis beam 10 extends along a first direction X; the first motor 11 and the second motor 12 are respectively arranged on both sides of the extension direction of the gantry axis beam 10, and the first motor 11 and the second motor 12 drive the gantry axis beam 10 to move along a second direction Y, and the first direction X is perpendicular to the second direction Y; the controller is used to execute the control method of the motion platform system provided by any embodiment of the present invention.

[0097] Optional, you can continue to refer to Figure 1 and Figure 2The motion table system also includes a single-axis driving structure, a third grating encoder 42 and a fourth grating encoder 43. The single-axis driving structure includes a single-axis shaft body 40 and a third motor 41. The single-axis shaft body 40 is located on the gantry axis cross beam 10. The third motor 41 is connected to the single-axis shaft body 40. The third motor 41 is used to drive the single-axis shaft body 40 to move along the extension direction of the gantry axis cross beam 10; the third grating encoder 42 and the fourth grating encoder 43 are respectively located on both sides of the single-axis shaft body 40 along the second direction Y, and the third grating encoder 42 and the fourth grating encoder 43 are jointly used to detect the position information of the single-axis shaft body 40.

[0098] The sports table system provided by the embodiment of the present invention includes all the technical features and corresponding beneficial effects of the control method of the sports table system provided by any embodiment of the present invention, which will not be repeated here.

[0099] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A control method for a motion table system, characterized in that: The motion platform system includes a gantry dual-drive structure, the gantry dual-drive structure includes a gantry axis beam, a first motor and a second motor, when the gantry dual-drive structure is in a mechanical balance posture, the gantry axis beam extends along a first direction; the first motor and the second motor are respectively arranged on both sides of the extension direction of the gantry axis beam, the first motor and the second motor drive the gantry axis beam to move along a second direction; the first direction is perpendicular to the second direction; the motion platform system also includes a single-axis drive structure, the single-axis drive structure includes a single-axis shaft body and a third motor, the single-axis shaft body is located on the gantry axis beam, the third motor is connected to the single-axis shaft body, and is used to drive the single-axis shaft body to move along the extension direction of the gantry axis beam; The control method of the motion table system comprises: Acquire the actual position information of the gantry axis crossbeam in the second direction and the actual rotation angle information of the third direction; the third direction rotates around the virtual symmetry axis of the gantry axis crossbeam, and the virtual symmetry axis is perpendicular to the first direction and the second direction; Determine the driving force resultant required by the gantry axis crossbeam in the second direction according to the actual position information, and determine the first torque required by the gantry axis crossbeam in the third direction according to the actual rotation angle information; Calculating a first driving force of the first motor and a second driving force of the second motor by combining the driving force resultant and the first torque; Before calculating the first driving force of the first motor and the second driving force of the second motor by combining the driving force resultant and the first torque, the method further includes: Calculating a feedforward compensation torque of the gantry axis crossbeam in the third direction according to the third driving force of the third motor; Calculating a second torque of the gantry axis beam in the third direction by combining the first torque and the feedforward compensation torque; Calculating a first driving force of the first motor and a second driving force of the second motor in combination with the driving force resultant and the first torque includes: The first driving force of the first motor and the second driving force of the second motor are calculated by combining the driving force resultant and the second torque.

2. The control method of the sports table system according to claim 1, characterized in that: The motion stage system further includes a third grating encoder and a fourth grating encoder; the third grating encoder and the fourth grating encoder are respectively located on both sides of the single-axis shaft body along the second direction, and the third grating encoder and the fourth grating encoder are used together to detect the position information of the single-axis shaft body; Among them, the feedforward compensation torque is T RWFF , the second torque is T RW , ， ； h is the distance between the center of mass of the single-axis body and the output point of the third motor in the second direction, F S is the third driving force of the third motor, T RWFB is the first torque.

3. The control method of the sports table system according to claim 2, characterized in that: The control method further comprises: During the system debugging stage, the single-axis shaft body servo is at the single-axis logic zero position, and controls the gantry axis crossbeam to move along the second direction, and identifies the first arm length and the second arm length of the gantry axis crossbeam with the center of mass of the gantry axis crossbeam as the axis center; the single-axis logic zero position is the initial position of the single-axis shaft body; Based on the first arm length and the second arm length, move the single-axis shaft body to the edge position of the gantry axis crossbeam along the first direction, and control the gantry axis crossbeam to move along the second direction to identify the single-axis mass ratio; Based on the first arm length, the second arm length and the single-axis mass ratio, the gantry axis crossbeam servo is at the gantry axis logic zero position, and the single-axis shaft body is controlled to move along the extension direction of the gantry axis crossbeam to identify the distance between the third motor output point and the center of mass of the single-axis shaft body in the second direction. h ; The logical zero position of the gantry axis is the initial position of the gantry axis crossbeam.

4. The control method of the sports table system according to claim 2, characterized in that: Before calculating the first driving force of the first motor and the second driving force of the second motor by combining the driving force resultant and the second torque, the method includes: Determine the mass center offset distance between the actual mass center of the gantry axis and the initial mass center of the gantry axis in the first direction; the initial mass center of the gantry axis is the mass center of the gantry axis crossbeam when it is at the logical zero position of the gantry axis; Calculating the first driving force of the first motor and the second driving force of the second motor by combining the driving force resultant and the second torque includes: The first driving force of the first motor and the second driving force of the second motor are calculated by combining the mass center offset distance, the driving force resultant, and the second torque.

5. The control method of the sports table system according to claim 4, characterized in that: The centroid offset distance is ∆ L GG , ； K m The single-axis mass ratio is obtained by identification during the system debugging phase. P S is the actual position of the uniaxial shaft body in the first direction; The first driving force is F 1 , the second driving force is F 2 , ； ； L 1 is the distance between the first motor output point and the initial center of mass of the gantry axis in the extension direction of the gantry axis crossbeam, L 2 is the distance between the second motor output point and the initial center of mass of the gantry axis in the extension direction of the gantry axis crossbeam, F G is the driving force resultant.

6. The control method of the sports table system according to claim 1, characterized in that: The motion stage system further comprises a first grating encoder and a second grating encoder, wherein the first grating encoder and the second grating encoder components are respectively located on both sides of the extension direction of the gantry axis cross beam; The actual location information is P G , the actual rotation angle information is P RW , ； ； P En1 is the grating scale reading of the first grating encoder, P En2 is the grating scale reading of the second grating encoder, L En is the distance between the first grating encoder and the second grating encoder in the extending direction of the gantry axis crossbeam.

7. The control method of the sports table system according to claim 1, characterized in that: Determining the driving force resultant required by the gantry axis crossbeam in the second direction according to the actual position information, and determining the first torque required by the gantry axis crossbeam in the third direction according to the actual rotation angle information, including: The driving force resultant is determined according to the difference between the actual position information and the target reference position information, and the first torque is determined according to the difference between the actual rotation angle information and the target reference rotation angle information.

8. The control method of the sports table system according to claim 1, characterized in that: The first driving force is F 1 , the second driving force is F 2 , ； ； L 1 is the distance between the first motor output point and the initial center of mass of the gantry axis in the extension direction of the gantry axis crossbeam, L 2 is the distance between the second motor output point and the initial center of mass of the gantry axis in the extension direction of the gantry axis crossbeam, F G is the driving force resultant, T RWFB is the first torque.

9. A control device for a sports table system, characterized in that: A control method for a sports table system according to any one of claims 1 to 8; The control device of the sports table system comprises: An actual motion information acquisition module, used to acquire actual position information of the gantry axis crossbeam in the second direction and actual rotation angle information of the third direction; the third direction rotates around a virtual symmetry axis of the gantry axis crossbeam, and the virtual symmetry axis is perpendicular to the first direction and the second direction; a driving force resultant and first torque determination module, configured to determine the driving force resultant required by the gantry axis crossbeam in the second direction according to the actual position information, and to determine the first torque required by the gantry axis crossbeam in the third direction according to the actual rotation angle information; a motor driving force decoupling module, configured to calculate a first driving force of the first motor and a second driving force of the second motor by combining the driving force resultant and the first torque; The driving force resultant force and first torque determination module is specifically used to calculate the feedforward compensation torque of the gantry axis crossbeam in the third direction according to the third driving force of the third motor; and calculate the second torque of the gantry axis crossbeam in the third direction in combination with the first torque and the feedforward compensation torque; The motor driving force decoupling module is specifically configured to calculate the first driving force of the first motor and the second driving force of the second motor by combining the driving force resultant and the second torque.

10. A sports table system, characterized in that: It includes a gantry dual-drive structure and a controller, wherein the controller is electrically connected to the gantry dual-drive structure; The gantry dual-drive structure comprises a gantry axis crossbeam, a first motor and a second motor. When the gantry dual-drive structure is in a mechanically balanced posture, the gantry axis crossbeam extends along a first direction; the first motor and the second motor are respectively arranged on both sides of the extension direction of the gantry axis crossbeam, and the first motor and the second motor drive the gantry axis crossbeam to move along a second direction, and the first direction is perpendicular to the second direction; The controller is used to execute the control method of the sports table system as described in any one of claims 1-8.

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