Gantry-platform kinematic modeling method taking into consideration parallelism and perpendicularity errors

Abstract

The present invention relates to the technical field of intelligent control, and especially relates to a gantry-platform kinematic modeling method taking into consideration parallelism and perpendicularity errors. The gantry-platform kinematic modeling method is applied to a gantry platform device, which comprises a cross beam, a first guide rail and a second guide rail, wherein one end of the cross beam is in sliding fit with the first guide rail, and the other end of the cross beam is in sliding fit with the second guide rail; the first guide rail is provided with a first longitudinal electric motor, and the second guide rail is provided with a second longitudinal electric motor; and the cross beam is provided with a transverse electric motor, which is used to drive a gantry platform to move along the cross beam. The method comprises: establishing a two-dimensional coordinate system; building a forward kinematics model; and building a backward kinematics model. The modeling method of the present invention is applicable to kinematic path planning for an actual gantry platform, and achieves high positioning accuracy; a gantry platform control method of the present invention achieves high positioning accuracy; and the gantry platform device of the present invention has a simple structure and high positioning accuracy, and forced deformation of the cross beam and connectors thereof during movement can also be prevented.

Description

A kinematic modeling method for gantry platforms considering parallelism and perpendicularity errors Technical Field

[0001] The present invention relates to the field of intelligent control technology, and in particular to a kinematic modeling method for a gantry platform taking parallelism and perpendicularity errors into consideration. Background Art

[0002] With the development of high-end manufacturing in China, dual-drive gantry systems, with their advantages of large travel and high speed, have become the dominant XY motion platforms in most high-end manufacturing equipment. This structure employs a dual-drive gantry system, with each end of the beam driven by a motor. Coupling between these redundantly driven motors is unavoidable, and achieving highly coordinated motion is crucial for ensuring the positioning accuracy of the motion platform's end points.

[0003] As shown in Figure 1, the two guide rails exhibited errors in parallelism, and the crossbeam and guide rails lacked perpendicularity. This caused the crossbeam and its connecting components to be severely deformed when motors Y1 and Y2 engaged in purely positional synchronization. This not only prevented the platform's end-position accuracy from being guaranteed, but also increased crossbeam vibration, energy consumption, and even structural damage.

[0004] There are methods in the prior art to improve the positioning accuracy of gantry platforms, such as the flexible gantry dual-drive system and its electromechanical combined decoupling motion control method disclosed in CN115390512B, which realizes the connection between motor Y1 and motor Y2 and the crossbeam through a flexible support device, making the structure of the gantry dual-drive system complex and the control method complex. Another example is a gantry platform calibration method and gantry platform disclosed in CN116803604A, which calculates the offset intersection and offset by measuring the coordinates of the calibration point, and calculates the gantry platform motion compensation amount by the offset. This patented technology does not take into account the errors in the parallelism of the two guide rails and the insufficient verticality accuracy of the crossbeam and the guide rails, resulting in low error measurement accuracy and difficulty in achieving more precise drive control.

[0005] Summary of the Invention

[0006] The purpose of the present invention is to propose a gantry platform kinematic modeling method that takes into account parallelism and perpendicularity errors, which is suitable for the kinematic planning path of an actual gantry platform and has high positioning accuracy;

[0007] Another object of the present invention is to provide a gantry platform control method, which uses the above-mentioned modeling method to achieve higher positioning accuracy of the gantry platform and prevent beam vibration.

[0008] Another object of the present invention is to provide a gantry platform device with a simple structure and high positioning accuracy, and can also avoid forced deformation of the beam and its connecting parts during movement.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] A gantry platform kinematic modeling method considering parallelism and perpendicularity errors is applied to a gantry platform device, the gantry platform device comprising a crossbeam, a first guide rail, and a second guide rail, wherein one end of the crossbeam is in sliding engagement with the first guide rail, and the other end of the crossbeam is in sliding engagement with the second guide rail; the first guide rail is provided with a first longitudinal motor, and the second guide rail is provided with a second longitudinal motor, the first longitudinal motor and the second longitudinal motor being connected to respective ends of the crossbeam; the crossbeam is provided with a transverse motor, and the transverse motor is used to drive the gantry platform to move along the crossbeam;

[0011] The method comprises the following steps:

[0012] (1) Establish a two-dimensional coordinate system

[0013] Taking the first guide rail as the reference guide rail and the initial position of the first longitudinal motor as the origin, a two-dimensional coordinate system O0 is established in the plane where the first guide rail and the second guide rail are located. In this coordinate system, the coordinates of the first longitudinal motor after movement are Y1′(0, y1), the coordinates of the second longitudinal motor after movement are Y2′(x2, y2), and the position coordinates of the gantry platform after movement are (x, y);

[0014] The length of the crossbeam is l, the parallelism error between the first guide rail and the second guide rail is α, and the perpendicularity error between the crossbeam and the first guide rail at the initial position of the first motor is β0;

[0015] (2) Constructing a kinematics model

[0016] It is known that the displacement of the first longitudinal motor, the second longitudinal motor and the transverse motor is y e1 、y e 2. x e , x z0 is the initial offset of the transverse motor, and the displacement x of the gantry platform is solved. r ,y r :

[0017] (3) Constructing the kinematic inverse solution model

[0018] The displacement x of the gantry platform is known r ,y r , solve the displacement y required for the first longitudinal motor, the second longitudinal motor and the transverse motor to move e1 、y e2 、x e :

[0019] Where β is the verticality error after movement.

[0020] Furthermore, in step (2), the steps of constructing the kinematics forward solution model are as follows:

[0021] It is known that the displacement of the first longitudinal motor, the second longitudinal motor and the transverse motor is y e1 、y e2 、x e , x z0 is the initial offset of the transverse motor;

[0022] Coordinate values ​​of each point: x0=x z0 ,y0=x z0 β0,y1=y e1 x2=l cos β0+y e2 α,y2=lβ0+y e2 cosα formula (1-1);

[0023] The verticality error β after movement is:

[0024] The end position x after movement is: x = x e1 cosβ0+x z0 Formula (1-3);

[0025] Then the kinematic solution value x r ,y r for:

[0026] Furthermore, in step (3), the steps of constructing the kinematic inverse solution model are as follows:

[0027] The displacement x of the gantry platform is known r ,y r , the values ​​of x, y, and x2 are: x = x z0 +x r ,y=x z0 β0+y r x2=l cosβ0+y r α formula (1-5);

[0028] According to the geometric relationship of the machine, the equations are obtained:

[0029] The solution to the coordinates (y1, y2) is:

[0030] The verticality error β after movement is:

[0031] The displacement y required for the first longitudinal motor, the second longitudinal motor and the transverse motor to move e1 、y e2 、x e :

[0032] Furthermore, in the formula (1-5), the value of x2 is an estimated value, so let y e2 ≈y r .

[0033] A gantry platform control method utilizing the aforementioned gantry platform kinematic modeling method considering parallelism and perpendicularity errors;

[0034] The gantry platform control method comprises the following steps:

[0035] Get the expected displacement x after the gantry platform moves r ,y r ;

[0036] The displacement x required for the transverse motor, the first longitudinal motor and the second longitudinal motor to move is obtained by the kinematic inverse solution model. e ,y e1 ,y e2 ;

[0037] Controlling the movement of the first longitudinal motor, the second longitudinal motor and the transverse motor;

[0038] Get the actual displacement x of the transverse motor, the first longitudinal motor and the second longitudinal motor t1 ,y t1 ,y t2 ;

[0039] The actual position (x, y) of the gantry platform after movement is obtained through the kinematic forward solution model;

[0040] The desired position after compensating the gantry platform movement (x r ,y r ) and the actual position (x,y).

[0041] Furthermore, the actual displacement x of the transverse motor, the first longitudinal motor and the second longitudinal motor is obtained by a displacement sensor. t1 ,y t1 ,y t2 .

[0042] Furthermore, the parallelism error α and the perpendicularity error β0 are obtained by measurement.

[0043] A gantry platform device, applying the above-mentioned gantry platform control method, the gantry platform device comprising a crossbeam, a first guide rail, and a second guide rail, one end of the crossbeam slidingly engaging with the first guide rail, and the other end of the crossbeam slidingly engaging with the second guide rail; the first guide rail is provided with a first longitudinal motor, the second guide rail is provided with a second longitudinal motor, the first longitudinal motor and the second longitudinal motor are respectively connected to the two ends of the crossbeam; the crossbeam is provided with a transverse motor, the transverse motor being used to drive the gantry platform to move along the crossbeam;

[0044] The gantry platform device further includes a controller and a displacement sensor, wherein the displacement sensor is used to sense the displacement of the transverse motor and the first longitudinal motor and the second longitudinal motor, and send the displacement data to the controller;

[0045] The controller stores the kinematics forward solution model and the kinematics inverse solution model, and is used to derive the displacement y required for the transverse motor, the first longitudinal motor, and the second longitudinal motor according to the expected displacement after the gantry platform moves and the kinematics inverse solution model. e1 ,y e2 ,x e , and sends movement instructions to the transverse motor, the first longitudinal motor, and the second longitudinal motor, and obtains a compensation deviation.

[0046] The technical solution provided by the present invention can have the following beneficial effects:

[0047] The above modeling method takes into account the errors in the parallelism of the two guide rails and the insufficient accuracy of the perpendicularity between the beam and the guide rails. By establishing a kinematic forward solution model and a kinematic inverse solution model, while ensuring the simple structure of the gantry device, the gantry platform positioning is more accurate and more suitable for the kinematic planning path of the actual gantry platform. While improving the positioning accuracy of the gantry platform, it solves the problems of forced deformation and vibration of the beam and insufficient positioning accuracy of the gantry platform caused by the errors in the parallelism of the guide rails and the perpendicularity between the beam and the guide rails. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] FIG1 is a schematic diagram of a beam being forced in an existing pure position synchronization control method;

[0049] FIG2 is a schematic diagram of a gantry platform device of the present invention;

[0050] FIG3 is a schematic diagram of the gantry platform motion taking into account parallelism and perpendicularity errors;

[0051] FIG4 is a diagram showing the results of a simulation experiment of the present invention;

[0052] FIG5 is a diagram showing the motion position of the gantry platform manipulator in the coordinate system o0 during the positioning experiment;

[0053] Figure 6 is a diagram of the positioning experiment results;

[0054] Among them, the crossbeam 1 , the first guide rail 2 , the second guide rail 3 , the first stator 41 , the second stator 51 , the third stator 61 , and the gantry platform 7 . DETAILED DESCRIPTION

[0055] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0056] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention. In addition, features defined as "first" or "second" may explicitly or implicitly include one or more such features, and are used to distinguish between the described features, without distinction of order or importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0058] In order to solve the problems of low positioning accuracy of the gantry platform due to the error in the parallelism of the two guide rails of the gantry platform and the insufficient perpendicularity accuracy between the crossbeam and the guide rail, as well as the problem of complex structure of the gantry dual-drive system in the prior art to solve this problem, the present invention proposes a gantry platform kinematic modeling method taking parallelism error into consideration, which is described below in conjunction with Figures 2 and 3.

[0059] A gantry platform kinematic modeling method that considers parallelism and perpendicularity errors is applied to a gantry platform device. The gantry platform device includes a crossbeam 1, a first guide rail 2, and a second guide rail 3. One end of the crossbeam 1 slides with the first guide rail 2, and the other end of the crossbeam 1 slides with the second guide rail 3. The first guide rail 2 is provided with a first longitudinal motor, and the second guide rail 3 is provided with a second longitudinal motor. The first longitudinal motor and the second longitudinal motor are respectively connected to the two ends of the crossbeam 1. The crossbeam 1 is provided with a transverse motor, which is used to drive the gantry platform 7 to move along the crossbeam 1.

[0060] The method comprises the following steps:

[0061] (1) Establish a two-dimensional coordinate system

[0062] With the first guide rail 2 as the reference guide rail and the initial position of the first longitudinal motor as the origin, a two-dimensional coordinate system O0 is established in the plane where the first guide rail 2 and the second guide rail 3 are located. In this coordinate system, the coordinates of the first longitudinal motor after movement are Y1′(0, y1), the coordinates of the second longitudinal motor after movement are Y2′(x2, y2), and the position coordinates of the gantry platform 7 after movement are (x, y);

[0063] The length of the crossbeam 1 is l, the parallelism error between the first guide rail 2 and the second guide rail 3 is α, and the perpendicularity error between the crossbeam 1 and the first guide rail 2 at the initial position of the first motor is β0;

[0064] (2) Constructing a kinematics model

[0065] It is known that the displacement of the first longitudinal motor, the second longitudinal motor and the transverse motor is y e1 ,y e2 , x e , x z0 is the initial offset of the transverse motor, and the displacement x of the gantry platform 7 is solved. r ,y r :

[0066] (3) Constructing the kinematic inverse solution model

[0067] The displacement x of the gantry platform 7 is known r ,y r , solve the displacement y required for the first longitudinal motor, the second longitudinal motor and the transverse motor to move e1 、y e2 、x e :

[0068] Where β is the verticality error after movement.

[0069] The above modeling method takes into account the errors in the parallelism of the two guide rails and the insufficient accuracy of the perpendicularity between the beam 1 and the guide rails. By establishing a kinematic forward solution model and a kinematic inverse solution model, while ensuring the simplicity of the structure of the gantry device, the positioning of the gantry platform 7 is more accurate and more suitable for the actual kinematic planning path of the gantry platform 7. While improving the positioning accuracy of the gantry platform 7, it solves the problems of forced deformation and vibration of the beam 1 and insufficient positioning accuracy of the gantry platform 7 caused by the errors in the parallelism of the guide rails and the perpendicularity between the beam 1 and the guide rails.

[0070] It should be noted that the displacement of the gantry platform 7 is equivalent to the displacement of the manipulator on the gantry platform 7 in the coordinate system O0.

[0071] Furthermore, in step (2), the steps for constructing the kinematics forward solution model are as follows:

[0072] It is known that the displacement of the first longitudinal motor, the second longitudinal motor and the transverse motor is y e1 、y e2 、x e , x z0 is the initial offset of the lateral motor;

[0073] Coordinate values ​​of each point: x0=x z0 , y0=x z0 β0,y1=y e1 x2=l cosβ0+y e2 α,y2=lβ0+y e2 cosα formula (1-1);

[0074] The verticality error β after movement is:

[0075] The end position x after movement is: x = x e1 cos β0+x z0 Formula (1-3);

[0076] Then the kinematic solution value x r ,y r for:

[0077] Furthermore, in step (3), the steps for constructing the inverse kinematics model are as follows:

[0078] The displacement x of the gantry platform 7 is known r ,y r , the values ​​of x, y, and x2 are: x = x z0 +x r , y = x z0 β0+y r x2=l cosβ0+y rα formula (1-5);

[0079] According to the geometric relationship of the machine, the equations are obtained:

[0080] The solution to the coordinates (y1, y2) is:

[0081] The verticality error β after movement is:

[0082] The displacement y required by the first longitudinal motor, the second longitudinal motor and the transverse motor e1 、y e2 、x e :

[0083] It should be noted that in formula (1-5), the value of x2 is an estimate, and its value should be: x2=l cosβ0+y e2 α, but y e2 Unknown value, let y e2 ≈y r , which can reduce the computational complexity and improve the computational speed without affecting the positioning accuracy.

[0084] Accordingly, the present invention also provides a gantry platform control method, which applies the above-mentioned kinematic modeling method of the gantry platform 7 considering parallelism and verticality errors;

[0085] The gantry platform control method includes the following steps:

[0086] Get the expected displacement x after the gantry platform 7 moves r ,y r ;

[0087] By using the inverse kinematics model, the displacement x required for the transverse motor, the first longitudinal motor and the second longitudinal motor is obtained. e ,y e1 ,y e2 ;

[0088] Controlling the movement of the first longitudinal motor, the second longitudinal motor and the transverse motor;

[0089] Get the actual displacement x of the transverse motor, the first longitudinal motor and the second longitudinal motor t1 ,y t1 ,y t2 ;

[0090] The actual position (x, y) of the gantry platform 7 after movement is obtained through the kinematics forward solution model;

[0091] The expected position after compensating the movement of the gantry platform 7 (xr ,y r ) and the actual position (x,y).

[0092] The gantry platform control method applies the above-mentioned kinematic modeling method of the gantry platform 7 considering the parallelism and perpendicularity errors, obtains the position required to control the movement of the three motors through the inverse kinematic model, and obtains the actual position of the three motors after movement, and then obtains the actual position of the gantry platform 7 after movement through the forward kinematic model. The actual position is used as feedback to compensate for the deviation, thereby greatly improving the positioning accuracy of the gantry platform 7.

[0093] Specifically, the actual displacement x of the transverse motor, the first longitudinal motor and the second longitudinal motor is obtained by the displacement sensor. t1 ,y t1 ,y t2 Exemplarily, the displacement sensor is a linear grating ruler with high detection accuracy. It is understood that the parallelism error α and the perpendicularity error β0 are obtained by measurement, and exemplary, they are obtained by laser measurement.

[0094] Correspondingly, the present invention also provides a gantry platform device, which applies the above-mentioned gantry platform control method. The gantry platform device includes a crossbeam 1, a first guide rail 2, and a second guide rail 3. One end of the crossbeam 1 slides with the first guide rail 2, and the other end of the crossbeam 1 slides with the second guide rail 3. The first guide rail 2 is provided with a first longitudinal motor, and the second guide rail 3 is provided with a second longitudinal motor. The first longitudinal motor and the second longitudinal motor are respectively connected to the two ends of the crossbeam 1. The crossbeam 1 is provided with a transverse motor, which is used to drive the gantry platform 7 to move along the crossbeam 1.

[0095] The gantry platform device further includes a controller and a displacement sensor, wherein the displacement sensor is used to sense the displacement of the transverse motor and the first longitudinal motor and the second longitudinal motor, and send the displacement data to the controller;

[0096] The controller stores a kinematics forward solution model and a kinematics inverse solution model. The controller is used to obtain the displacement x required for the transverse motor, the first longitudinal motor and the second longitudinal motor according to the expected displacement after the gantry platform 7 moves and the kinematics inverse solution model. e ,y e1 ,y e2 and sends movement instructions to the transverse motor, the first longitudinal motor, and the second longitudinal motor, and obtains a compensation deviation.

[0097] It is understood that the controller includes a feedback controller and an end trajectory feedback controller. Each of the transverse motor, the first longitudinal motor, and the second longitudinal motor has a corresponding feedback controller. The end trajectory feedback controller is used to derive the displacement x required for the transverse motor, the first longitudinal motor, and the second longitudinal motor based on the expected displacement after the gantry platform 7 moves and the kinematic inverse solution model. e ,y e1 ,y e2 The feedback controller is used to receive the displacement signal from the displacement sensor, and is also used to receive the control signal sent by the end trajectory feedback controller and send control instructions to the motor.

[0098] Referring to Figure 2, in a gantry platform device according to one embodiment of the present invention, the transverse motor, the first longitudinal motor, and the second longitudinal motor are all linear motors. The first stator 41 of the first longitudinal motor is parallel to the first guide rail 2, and the second stator 51 of the second longitudinal motor is parallel to the second guide rail 3. The two ends of the crossbeam 1 are respectively connected to the first mover and the second mover. The third stator 61 of the transverse motor is fixed to the crossbeam 1, and the third mover is connected to the gantry platform. Because there is a certain gap between the stator and mover of the linear motor to enable smooth movement of the mover, the existence of parallelism error and perpendicularity error does not affect the normal operation of the three motors. Using linear motors as drive components can simplify the structure of the gantry platform device, making it lightweight and more suitable for the processing of precision components.

[0099] Based on the above gantry platform control method and gantry platform device, a simulation experiment is carried out. Set the displacement x of the gantry platform 7 r ,y r is 0.2m. Theoretically, the error between the kinematic solution and the inverse kinematic solution should be equal to 0. However, the error in formula (1-5) for y e2 An estimate was made, resulting in the 8 × 10 -14 The error of m is much smaller than the noise of the actual motion. Therefore, this estimate does not affect the accuracy of the proposed kinematic forward and inverse solutions.

[0100] The gantry platform control method of the present invention is compared with the existing pure position synchronization control method in a positioning experiment. Figure 5 is a motion position diagram of the end of the manipulator installed on the gantry platform 7 in the positioning experiment in the coordinate system o0. The motion trajectory is a circle with a diameter of 100mm. There are 63 positioning points in the trajectory. The end positioning accuracy is measured by a laser interferometer. The steps of the existing pure position synchronization control method are as follows: the expected displacement after the first longitudinal motor moves is y r , that is, the displacement that the first longitudinal motor needs to move is y r ; Make the first longitudinal motor and the second longitudinal motor move synchronously, and obtain the actual position y after the first longitudinal motor moves t1 ,y t1As the target motion displacement of the second longitudinal motor; the desired displacement x of the transverse motor r Target motion displacement as a lateral motor.

[0101] The positioning experiment results are shown in FIG6 . The maximum positioning errors in the XY directions of the existing pure position synchronization control method are all around 10 μm, while the maximum positioning errors in the method of the present invention are reduced to below 4 μm, indicating that the positioning accuracy of the present invention is significantly improved compared with the existing pure position synchronization method.

[0102] Other components and operations of the gantry platform kinematic modeling method considering parallelism and perpendicularity errors according to an embodiment of the present invention are well known to those skilled in the art and will not be described in detail here.

[0103] Throughout this specification, reference to terms such as "embodiment" or "example" indicates that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0104] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A gantry platform control method, characterized in that: Applied to a gantry platform device, the gantry platform device includes a crossbeam, a first guide rail, and a second guide rail, one end of the crossbeam slidingly cooperates with the first guide rail, and the other end of the crossbeam slidingly cooperates with the second guide rail; the first guide rail is provided with a first longitudinal motor, and the second guide rail is provided with a second longitudinal motor, and the first longitudinal motor and the second longitudinal motor are respectively connected to the two ends of the crossbeam; the crossbeam is provided with a transverse motor, and the transverse motor is used to drive the gantry platform to move along the crossbeam; The kinematic modeling method for the gantry platform considering parallelism and perpendicularity errors includes the following steps: (1) Establish a two-dimensional coordinate system Taking the first guide rail as the reference guide rail and the initial position of the first longitudinal motor as the origin, a two-dimensional coordinate system o0 is established in the plane where the first guide rail and the second guide rail are located. In this coordinate system, the coordinates of the first longitudinal motor after movement are Y1′(0, y1), the coordinates of the second longitudinal motor after movement are Y2′(x2, y2), and the position coordinates of the gantry platform after movement are (x, y); The length of the crossbeam is l, the parallelism error between the first guide rail and the second guide rail is α, and the perpendicularity error between the crossbeam and the first guide rail at the initial position of the first longitudinal motor is β0; (2) Constructing a kinematics model It is known that the displacement of the first longitudinal motor, the second longitudinal motor and the transverse motor is y e1 、y e2 、x e , x z0 is the initial offset of the transverse motor, and the displacement x of the gantry platform is solved. r ,y r : (3) Constructing the kinematic inverse solution model The displacement x of the gantry platform is known r ,y r , solve the first longitudinal motor and the second longitudinal motor The displacement y required for the machine and the transverse motor to move e1 、y e2 、x e : Where β is the verticality error after movement; The gantry platform control method comprises the following steps: Get the expected displacement x after the gantry platform moves r ,y r ; The displacement x required for the transverse motor, the first longitudinal motor and the second longitudinal motor to move is obtained by the kinematic inverse solution model. e ,y e1 ,y e2 ; Controlling the movement of the first longitudinal motor, the second longitudinal motor and the transverse motor; Get the actual displacement x of the transverse motor, the first longitudinal motor and the second longitudinal motor t1 ,y t1 ,y t2 ; The actual position (x, y) of the gantry platform after movement is obtained through the kinematic forward solution model; The desired position after compensating the gantry platform movement (x r ,y r ) and the actual position (x, y).

2. The method according to claim 1, characterized in that In step (2), the steps of constructing the kinematics forward solution model are as follows: It is known that the displacement of the first longitudinal motor, the second longitudinal motor and the transverse motor is y e1 、y e2 、x e , x z0 is the initial offset of the transverse motor; Coordinate values of each point: x0=x z0 ,y0=x z0 β0, y1=y e1 x2 = l cosβ0 + y e2 ɑ, y2 = lβ0 + y e2 cosɑ formula (1-1); The verticality error β after movement is: The end position x after movement is: x=x e cosβ0+x z0 Formula (1-3); Then the kinematic solution value x r ,y r for:

3. The method according to claim 1, characterized in that In step (3), the steps of constructing the kinematic inverse solution model are as follows: The displacement x of the gantry platform is known r ,y r , then the values of x, y, and x2 are: x=x z0 +x r ,y=x z0 β0+y r x2 = l cosβ0 + y r α formula (1-5); Obtain the system of equations based on geometric relations: The solution to the coordinates (y1, y2) is: The verticality error β after movement is: The displacement y required for the first longitudinal motor, the second longitudinal motor and the transverse motor to move e1 、y e2 、x e :

4. The method according to claim 3, characterized in that In the formula (1-5), the value of x2 is an estimated value, let y e2 ≈y r .

5. The gantry platform control method according to claim 1, characterized in that: The actual displacement x of the transverse motor, the first longitudinal motor and the second longitudinal motor is obtained by a displacement sensor. t1 ,y t1 ,y t2 .

6. The gantry platform control method according to claim 1, characterized in that: The parallelism error α and the perpendicularity error β0 are obtained by measurement.

7. A gantry platform device, characterized in that: Applying the gantry platform control method according to claim 1, the gantry platform device further comprises a controller and a displacement sensor, wherein the displacement sensor is used to sense the displacement of the transverse motor and the first longitudinal motor and the second longitudinal motor, and send the displacement data to the controller; The controller stores the kinematics forward solution model and the kinematics inverse solution model, and is used to derive the displacement y required for the first longitudinal motor, the second longitudinal motor, and the transverse motor according to the expected displacement after the gantry platform moves and the kinematics inverse solution model. e1 ,y e2 ,x e , and sends movement instructions to the transverse motor, the first longitudinal motor, and the second longitudinal motor, and obtains a compensation deviation.

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