Multi-module integrated calibration method for laser mass transfer system

Abstract

A multi-module integrated calibration method for a laser mass transfer system comprises the following steps that parameters to be calibrated are determined based on the laser mass transfer system and coordinate systems of all modules of the laser mass transfer system; determining an initial value of a to-be-calibrated parameter; constructing a conversion matrix from a pixel coordinate system to a calibration plate coordinate system through a coordinate system conversion matrix of each module; calculating the coordinate of the re-projection point of the calibration feature point in the pixel coordinate system; calculating by using an image processing algorithm to obtain coordinates of the calibration feature points in a pixel coordinate system; by adopting a least square method, taking the minimum re-projection error as a target function, and performing nonlinear optimization on the to-be-calibrated parameters by utilizing an iteration method to complete integrated calibration of multi-module error parameters; according to the invention, simultaneous calculation and optimization of internal parameters and external parameters of the camera and kinematics parameters of the parallel motion platform are realized, and the problem of error propagation is avoided; the invention also comprises a system, equipment and a medium for implementing the method.

Description

Technical Field

[0001] The present invention relates to the technical field of system calibration, and particularly relates to a multi-module integrated calibration method for a laser mass transfer system. Background Art

[0002] The laser mass transfer system mainly consists of modules such as a vision camera, a precision motion platform, and a laser galvanometer. In view of the high alignment accuracy requirements in the laser mass transfer process, high requirements are put forward for the error calibration of the overall system. The detection accuracy of the vision camera is a key link in the motion accuracy of the laser mass transfer system, and the quality of camera calibration is crucial for the measurement accuracy of the vision system. On the other hand, the motion accuracy of the precision motion platform is also an important part determining the overall accuracy of the laser mass transfer system. Errors will inevitably occur during the processing, manufacturing, and assembly of the motion platform. Therefore, calibrating the kinematic errors of the motion platform is a necessary process to improve the accuracy of the motion platform.

[0003] Traditional calibration methods generally adopt a step-by-step calibration method. First, the camera parameters are calibrated, and then the camera parameters are used as known quantities to measure the pose errors of the motion platform for calibrating the precision motion platform. For example, the invention with the patent application number CN202011614377.8 discloses a method that uses a step-by-step calibration method, that is, a camera with pre-calibrated internal parameters is used to calibrate the kinematic parameters of the parallel platform. Although this step-by-step calibration method has the advantages that the individual calibration tasks of each module are relatively simple, and when changing the position or parameters of the module, only the module needs to be calibrated separately. However, in terms of considering the calibration errors of each module, this calibration method has the drawback that the calibration errors of the previous module will propagate to the next module. Summary of the Invention

[0004] To solve the above problems, the object of the present invention is to propose a multi-module integrated calibration method for a laser mass transfer system, which realizes the simultaneous solution and optimization of the internal parameters, external parameters of the camera, and the kinematic parameters of the precision platform, and can avoid the error propagation problem among the calibration errors of each module in the separate calibration of multiple modules in the laser mass transfer device.

[0005] To achieve the above object, the technical solution of the present invention is as follows:

[0006] A multi-module integrated calibration method for a laser mass transfer system specifically includes the following steps:

[0007] S1. Determine the parameters to be calibrated, including the camera internal parameter matrix M, the camera distortion coefficient D, and the overall kinematic parameters ρ of the platform, based on the coordinate systems of the laser mass transfer system and its various modules; the coordinate systems of the various modules are respectively: the pixel coordinate system 301, the world coordinate system 101, the end effector coordinate system 102, the calibration board coordinate system 201, and the camera coordinate system 302;

[0008] S2. Determine the initial values of the parameters to be calibrated;

[0009] S3. Construct the transformation matrix from the pixel coordinate system 301 to the calibration board coordinate system 201 through the transformation matrix from the pixel coordinate system 301 considering lens distortion to the world coordinate system 101, the transformation matrix from the world coordinate system 101 to the end effector coordinate system 102, and the transformation matrix from the end effector coordinate system 102 to the calibration board coordinate system 201;

[0010] S4. Select calibration feature points, obtain the coordinate positions of the calibration feature points in the calibration board coordinate system 201 through the coordinate definition rules, and calculate the coordinates of the reprojection points of the calibration feature points in the pixel coordinate system 301;

[0011] S5. The camera captures the marker image, and uses the image processing algorithm to calculate the coordinates of the calibration feature points in the pixel coordinate system 301;

[0012] S6. Adopt the least squares method, take minimizing the reprojection error as the objective function, and use the iterative method to perform nonlinear optimization on the parameters to be calibrated to complete the integrated calibration of the multi-module error parameters.

[0013] The specific steps of step S1 are as follows:

[0014] There are a total of five coordinate systems for the various modules, which are respectively the pixel coordinate system 301 {u, v}, the world coordinate system 101 {x w , y w , z w}, the end effector coordinate system 102 {x t , y t , z t}, the calibration board coordinate system 201 {x cal , y cal , z cal}, and the camera coordinate system 302 {x c , y c , z c}. The coordinate transformation matrix between the five coordinate systems is in the form of a homogeneous transformation matrix where the rotation matrix The translation matrix T = [t x t y t z T , specifically:​

[0015] (1) represents the coordinate transformation matrix from the camera coordinate system 302 to the world coordinate system 101, named the camera-world transformation matrix;

[0016] (2) represents the coordinate transformation matrix from the camera coordinate system 302 to the calibration board coordinate system 201, named the camera-calibration board transformation matrix;

[0017] (3) represents the coordinate transformation matrix from the calibration board coordinate system 201 to the end effector coordinate system 102, named the calibration board-end effector transformation matrix;

[0018] (4) represents the coordinate transformation matrix from the end effector coordinate system 102 to the world coordinate system 101, named the end effector-world transformation matrix;

[0019] (5) The world coordinate system 101 is fixed at the center of the base of the precision motion platform;

[0020] Camera internal parameter matrix The camera distortion coefficient D = [k1 k2], and the overall kinematic parameters of the platform ρ = [ρ1 ρ2... ρ n T , which is the kinematic parameter set of the camera-world transformation matrix calibration board-end effector transformation matrix and the end effector-world transformation matrix coupled in the parameters of the rotation matrix R and the translation matrix T.

[0021] The initial value determination of the parameters to be calibrated in step S2 is specifically as follows:

[0022] The initial values of the camera internal parameter matrix M, the camera distortion coefficient D, and the camera-calibration board transformation matrix are obtained by calculating from the camera specification parameters and the Zhang Zhengyou calibration method; the initial value of the camera-world transformation matrix is given by the design value of the laser mass transfer system; the initial value of the end effector-world transformation matrix is provided by the design drawing of the precision alignment motion platform, and the accuracy is guaranteed by machining and assembly; the calibration board-end effector transformation matrix is calculated after the movement of the precision alignment platform.

[0023] Step S3 is specifically as follows:

[0024] The transformation matrix from the pixel coordinate system 301 considering lens distortion to the calibration board coordinate system 201 is specifically: Dist represents the non-linear transformation caused by the distortion coefficient D; ​

[0025] The coordinate transformation matrix from the camera coordinate system 302 to the calibration board coordinate system 201 can be constructed from the coordinate transformation matrix from the camera coordinate system 302 to the world coordinate system 101 the transformation matrix from the world coordinate system 101 to the end - effector coordinate system 102 and the transformation matrix from the end - effector coordinate system 102 to the calibration board coordinate system 201, specifically: Specifically:

[0026]

[0027] Therefore, the transformation matrix from the pixel coordinate system 301 to the calibration board coordinate system 201 is rewritten as:

[0028]

[0029] The specific steps of step S4 are as follows:

[0030] The marked feature points are any corner points, dot points or custom feature markers on the calibration board. The spacing and angle between the marked feature points are known. The forms of the calibration board include checkerboards, dot boards or coded disks;

[0031] The definition rule of the calibration board coordinate system is: Place the calibration board coordinate system at the pattern center of the feature marker. After defining the calibration board coordinate system, determine the coordinate positions (x cali , y cali , z cali ) of the marked feature points in the calibration board coordinate system 201 according to the spacing and angle between the marked feature points, where i represents the number of feature points;

[0032] The coordinates of the reprojection points of the calibrated feature points in the pixel coordinate system 301 are calculated by the following formula:

[0033]

[0034] The specific steps of step S5 are as follows:

[0035] The image - processing algorithm for the marker image is selected according to the shape of the feature points of the selected feature marker, including dot - detection algorithms, corner - detection algorithms or template - matching algorithms. Its purpose is to extract the coordinates A i (u i , v i ) of the feature points in the pixel coordinate system 301.

[0036] The specific steps of step S6 are as follows:

[0037] The minimization of the reprojection error function using the least - squares method is specifically:

[0038]

[0039] Among them, A is the coordinate of the feature point in the pixel coordinate system, A' is the coordinate of the feature point reprojected into the pixel coordinate system, M is the camera internal parameter, D is the camera distortion parameter, ρ is the system kinematic parameter, m is the number of poses of the precision motion platform for displacement, and n is the number of checkerboard corner points used for calculation;

[0040] The non-linear optimization adopts the Levenberg-Marquardt algorithm, sets the iteration convergence threshold, and the optimization result converges quickly, making the overall error minimum.

[0041] The present invention also includes a system, including a calibration module, which can run the above-mentioned multi-module integrated calibration method for a laser mass transfer system.

[0042] The present invention also includes a device, including:

[0043] A memory: used to store a computer program for implementing the above-mentioned multi-module integrated calibration method for a laser mass transfer system;

[0044] A processor: used to implement the above-mentioned multi-module integrated calibration method for a laser mass transfer system when executing the computer program.

[0045] The present invention also includes a computer-readable storage medium, and the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the above-mentioned multi-module integrated calibration method for a laser mass transfer system.

[0046] Compared with the existing step-by-step calibration technology, the present invention has the following advantages:

[0047] (1) In step 3, through the coordinate transformation relationship, the coupling of the platform kinematic parameter and the camera calibration board transformation matrix is realized, and during the subsequent work process of the platform, the calibration parameters can be updated in real time by the real-time acquisition of images by the camera and the acquisition of the platform's own motion data, which can maximize the utilization of the requirements suitable for dynamic environments and online calibration.

[0048] (2) From step 4 to step 5, an error minimum reprojection error function is constructed by data support such as the image data collected by the camera and the motion data measured by the displacement sensors of each motor of the platform. During the process of optimizing the error function, the data collected by the sensors can be maximally utilized.

[0049] (3) Step 6 adopts the Levenberg-Marquardt optimization algorithm to perform non-linear optimization on the error function, realizing the simultaneous solution and optimization of the camera internal parameters, external parameters, and the kinematic parameters of the parallel motion platform, and can avoid the error propagation problem between the calibration errors of each module in step-by-step calibration.

[0050] In summary, the present invention realizes the simultaneous solution and optimization of the internal parameters, external parameters of the camera, and the kinematic parameters of the parallel kinematic platform, which can avoid the error propagation problem between the calibration errors of each module in the separate calibration of multiple modules in the laser mass transfer device; because it can solve all parameters simultaneously, the calibration process is simplified, the efficiency is improved, it is suitable for dynamic environments and online calibration requirements, and the data collected by the sensor can be maximally utilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 FIG. is a schematic structural diagram of a laser mass transfer system provided by an embodiment of the present invention.

[0052] Figure 2 FIG. is a schematic diagram of a laser mass transfer calibration system provided by an embodiment of the present invention.

[0053] Reference numerals: 1, precision alignment platform; 101, world coordinate system; 102, end coordinate system; 2, calibration plate; 201, calibration plate coordinate system; 3, vision camera; 301, pixel coordinate system; 302, camera coordinate system. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application. In the following description, the same modules are denoted by the same reference numerals, and their names and functions are also the same, and their detailed descriptions will not be repeated.

[0055] A multi-module integrated calibration method for a laser mass transfer system calibrates a laser mass transfer calibration system; as Figure 1 shown in the laser mass transfer calibration system, it includes a precision alignment platform 1, a calibration plate 2, and a vision camera 3; as Figure 2 shown in the laser mass transfer calibration system coordinate system, it includes a world coordinate system 101, an end coordinate system 102, a calibration plate coordinate system 201, a pixel coordinate system 301, and a camera coordinate system 302.

[0056] The coordinate transformation matrix between the five coordinate systems in the calibration system is in the form of a homogeneous transformation matrix Specifically:

[0057] (1) represents the coordinate transformation matrix from the camera coordinate system 302 to the world coordinate system 101, named the camera-world transformation matrix;

[0058] (2) Represents the coordinate transformation matrix from the camera coordinate system 302 to the calibration board coordinate system 201, named the camera calibration board transformation matrix;

[0059] (3) Represents the coordinate transformation matrix from the calibration board coordinate system 201 to the end effector coordinate system 102, named the calibration board end effector transformation matrix;

[0060] (4) Represents the coordinate transformation matrix from the end effector coordinate system 102 to the world coordinate system 101, named the end effector world transformation matrix;

[0061] (5) The world coordinate system 101 is fixed at the center of the base of the precision motion platform;

[0062] The parameters to be calibrated include:

[0063] The camera internal parameter matrix M, the camera distortion coefficient D, the camera world transformation matrix The calibration board end effector transformation matrix and the end effector world transformation matrix and other kinematic parameters ρ = [ρ1 ρ2... ρ n T ;

[0064] The specific calibration method of the present invention is as follows:

[0065] S1. Based on the coordinate systems of the laser mass transfer system and its various modules, determine the parameters to be calibrated, including the camera internal parameter matrix M, the camera distortion coefficient D, and the kinematic parameters ρ of the platform.

[0066] Specifically, the world coordinate system 101 is selected as the center of the base of the precision alignment platform, which is a fixed coordinate system, and the end effector coordinate system 102 is selected as the center of the end effector of the precision alignment platform, which is a variable coordinate system;

[0067] Considering that the camera manufacturing error and the camera distortion error are relatively small, the camera internal parameter matrix is selected The camera distortion coefficient D = [k1 k2], the camera world transformation matrix The calibration board end effector transformation matrix and the end effector world transformation matrix The kinematic parameters are expressed as the overall kinematic parameters ρ = [ρ1 ρ2... ρ n T , which are coupled in the parameters of the rotation matrix R and the translation matrix T.

[0068] S2. Determine the initial values of the parameters to be calibrated.​​

[0069] Specifically, the initial values of the camera internal parameter matrix M, the camera distortion coefficient D, and the camera calibration board transformation matrix are obtained by calculating according to the camera specification parameters and the Zhang Zhengyou calibration method; the initial value of the camera world transformation matrix is given by the design value of the laser mass transfer system; the initial value of the end effector world transformation matrix is provided by the design drawing of the precision alignment motion platform, and the accuracy is guaranteed by machining and assembly; the calibration board end effector transformation matrix is calculated after the movement of the precision alignment platform.

[0070] S3. By considering the transformation matrix from the pixel coordinate system 301 to the world coordinate system 101, the transformation matrix from the world coordinate system 101 to the end effector coordinate system 102, and the transformation matrix from the end effector coordinate system 102 to the calibration board coordinate system 201 after considering lens distortion, construct the transformation matrix from the pixel coordinate system 301 to the calibration board coordinate system 201.

[0071] The transformation matrix from the pixel coordinate system 301 considering lens distortion to the calibration board coordinate system 201 is specifically: Dist represents the non-linear transformation caused by the distortion coefficient D;

[0072] The camera calibration board transformation matrix can be constructed from the camera world coordinate transformation matrix with a known initial value, the world end effector transformation matrix with known movement, and the solved end effector calibration board transformation matrix as:

[0073] Specifically, the calibration board end effector transformation matrix is calculated after the movement of the precision alignment platform. After the camera captures the pixel coordinates of the checkerboard corner points, the precision alignment platform is used to perform sufficient displacements in the three degrees of freedom of XYθ, such as 2 groups of 6 specific displacements of pure translation and pure rotation movements. It is required that the checkerboard image is within the camera's field of view during each group of movements. After each group of movements is completed, record the pixel coordinates of the checkerboard corner points after the corresponding movement, and calculate the calibration board end effector transformation matrix through the geometric method

[0074] Specifically, because as the precision alignment platform moves, the end effector world transformation matrix will change accordingly, and the camera calibration board transformation relationship will also change accordingly. Since the displacement performed by the precision alignment platform is a simple two-dimensional planar movement and is known, the end effector world transformation matrix after each movement can be determined through a simple rigid body transformation relationship, thereby deriving the camera calibration board transformation relationship For subsequent calibration optimization.

[0075] S4. Select calibration feature points, obtain the coordinate positions of the calibration feature points in the calibration board coordinate system 201 through the coordinate system definition rules, and calculate the coordinates of the reprojection points of the calibration feature points in the pixel coordinate system 301.

[0076] Specifically, a checkerboard is used as the calibration board, and the feature points in its feature markers are the corner points of the checkerboard. The calibration board coordinate system is fixed at the central corner point of the pattern on the checkerboard plane. According to the grid size of the checkerboard, the coordinates (x cali , y cali , z cali ) of each corner point in the calibration board coordinate system are obtained;

[0077] Therefore, the conversion relationship between the pixel coordinate system and the calibration board coordinate system considering lens distortion is derived from the M, D, and coordinate transformation relationship. The specific coordinates of the corner points in the corresponding pixel coordinate system calculated from the corner point coordinates of the calibration board coordinate system are:

[0078]

[0079] S5. The camera captures the marker image, and uses an image processing algorithm to calculate the coordinates of the calibration feature points in the pixel coordinate system 301.

[0080] The image processing algorithm for the marker image needs to be selected according to the shape of the feature points of the selected feature marker, including but not limited to circle detection algorithms, corner detection algorithms, template matching algorithms, etc. The purpose is to extract the coordinates A i (u i , v i ) of the feature points in the pixel coordinate system 301. Specifically, after the camera takes a picture of the checkerboard, the Harris corner detection algorithm is used to detect the coordinates A i (u i , v i ) of each corner of the checkerboard in the pixel coordinate system 301.

[0081] Specifically, the pixel coordinates A i (u i , v i ) of the checkerboard corners detected by the camera are used as the actual values, and the calculated checkerboard corner coordinates A' i (u' i , v' i ) are used as the predicted values. The reprojection error equation of the feature points considering lens distortion is constructed as:

[0082] e = A i - A i '.

[0083] S6. Using the least squares method, taking the minimization of the reprojection error as the objective function, and using the iterative method to perform non-linear optimization on the parameters to be calibrated, so as to complete the integrated calibration of the multi-module error parameters.

[0084] Using the least squares error cost function, adopting the Levenberg-Marquardt algorithm, and setting a reasonable iterative convergence threshold to minimize the reprojection error, and iteratively optimizing and calculating each error parameter. The expression is:

[0085]

[0086] Among them, A is the coordinate of the feature point in the pixel coordinate system, A' is the coordinate of the feature point reprojected into the pixel coordinate system, M is the camera internal parameter, D is the camera distortion parameter, ρ is the system kinematic parameter, m is the number of poses of the precision motion platform for displacement, and n is the number of checkerboard corner points used for calculation.

[0087] Regarding the correlation between the pixel coordinate system and the calibration board coordinate system, among them, the pixel coordinates of the actual feature points are measured by the vision camera, and the pixel coordinates of the predicted feature points are calculated by the coordinate system definition rules and the motion of the precision alignment platform. The main difference between this method and the traditional step-by-step calibration method is that all error parameters can be iteratively calculated simultaneously according to the above formula. A single feature marker point can only provide two constraint conditions. Therefore, in order to calculate more accurate error parameters, it is necessary to measure and calculate the coordinates of enough feature marker points.

[0088] The present invention also includes a system, including a calibration module that can run the above-mentioned multi-module integrated calibration method for a laser mass transfer system.

[0089] The present invention also includes a device, including:

[0090] A memory: used to store a computer program for implementing the above-mentioned multi-module integrated calibration method for a laser mass transfer system;

[0091] A processor: used to implement the above-mentioned multi-module integrated calibration method for a laser mass transfer system when executing the computer program.

[0092] The present invention also includes a computer-readable storage medium, the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned multi-module integrated calibration method for a laser mass transfer system is implemented.

[0093] It should be noted that in this application, each step can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved, and no further limitations will be provided herein.

[0094] The above are only specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application will not be limited to these embodiments shown herein, but rather will conform to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A multi-module integrated calibration method for a laser mass transfer system, characterized in that Specifically, it includes the following steps: S1. Based on the coordinate systems of the laser mass transfer system and its various modules, determine the parameters to be calibrated, including the camera internal parameter matrix M, the camera distortion coefficient D, and the overall kinematic parameter ρ of the platform; the coordinate systems of the various modules are respectively: pixel coordinate system (301), world coordinate system (101), end coordinate system (102), calibration board coordinate system (201), and camera coordinate system (302); S2. Determine the initial values of the parameters to be calibrated; S3. Construct the transformation matrix from the pixel coordinate system (301) to the calibration board coordinate system (201) through the transformation matrix from the pixel coordinate system (301) considering lens distortion to the world coordinate system (101), the transformation matrix from the world coordinate system (101) to the end coordinate system (102), and the transformation matrix from the end coordinate system (102) to the calibration board coordinate system (201); S4. Select calibration feature points, obtain the coordinate positions of the calibration feature points in the calibration board coordinate system (201) through the coordinate definition rules, and calculate the coordinates of the reprojection points of the calibration feature points in the pixel coordinate system (301); S5. The camera captures the marker image, and uses the image processing algorithm to calculate the coordinates of the calibration feature points in the pixel coordinate system (301); S6. Adopt the least squares method, use the minimization of the reprojection error as the objective function, and use the iterative method to perform nonlinear optimization on the parameters to be calibrated to complete the integrated calibration of the multi-module error parameters.

2. The multi-module integrated calibration method for a laser mass transfer system according to claim 1, wherein The specific content of step S1 is as follows: There are a total of five coordinate systems for each of the modules, namely the pixel coordinate system (301) {u, v}, the world coordinate system (101) {x w , y w , z w}, the end coordinate system (102) {x t , y t , z t}, the calibration board coordinate system (201) {x cal , y cal , z cal}, and the camera coordinate system (302) {x c , y c , z c}. The coordinate transformation matrix between the five coordinate systems is in the form of a homogeneous transformation matrix where the rotation matrix The translation matrix T = [t x t y t z T , specifically: (1) Represents the coordinate transformation matrix from the camera coordinate system (302) to the world coordinate system (101), named the camera-world transformation matrix; (2) represents the coordinate transformation matrix from the camera coordinate system (302) to the calibration board coordinate system (201), named the camera calibration board transformation matrix; (3) Represents the coordinate transformation matrix from the calibration board coordinate system (201) to the end - effector coordinate system (102), named the calibration board - end - effector transformation matrix; (4) represents the coordinate transformation matrix from the end - effector coordinate system (102) to the world coordinate system (101), named the end - effector to world transformation matrix; (5) The world coordinate system (101) is fixed at the center of the base of the precision motion platform; Camera intrinsic matrix The camera distortion coefficient D = [k1 k2], and the overall kinematic parameters of the platform ρ = [ρ1 ρ2... ρ n T , which is the camera world transformation matrix The end conversion matrix of the calibration board and the end world transformation matrix is a set of kinematic parameters, which are coupled in the parameters of the rotation matrix R and the translation matrix T.​ 3. The multi-module integrated calibration method for a laser mass transfer system according to claim 2, characterized in that, The determination of the initial values of the parameters to be calibrated in step S2 is specifically as follows: The initial values of the camera internal parameter matrix M, the camera distortion coefficient D, and the camera calibration board transformation matrix are obtained by calculating from the camera specification parameters and the Zhang Zhengyou calibration method; the initial value of the camera world transformation matrix is given by the design value of the laser mass transfer system; the initial value of the end-effector world transformation matrix is provided by the design drawing of the precision alignment motion platform, and the accuracy is guaranteed by machining and assembly; Calibration plate end transformation matrix Calculated from the movement of the precision alignment platform 4. A multi-module integrated calibration method for a laser mass transfer system according to claim 2, characterized in that, The specific content of step S3 is as follows: The conversion matrix from the pixel coordinate system (301) considering lens distortion to the calibration board coordinate system (201) is specifically as follows: Dist represents the non - linear transformation caused by the distortion coefficient D; The coordinate transformation matrix from the camera coordinate system (302) to the calibration board coordinate system (201) can be constructed from the coordinate transformation matrix from the camera coordinate system (302) to the world coordinate system (101) the transformation matrix from the world coordinate system (101) to the end - effector coordinate system (102) and the transformation matrix from the end - effector coordinate system (102) to the calibration board coordinate system (201) Specifically, it is constructed as follows: Therefore, the transformation matrix from the pixel coordinate system (301) to the calibration board coordinate system (201) is rewritten as:

5. A multi-module integrated calibration method for a laser mass transfer system according to claim 4, characterized in that The specific content of step S4 is as follows: The marked feature points are any corner points, dot points or custom feature markers on the calibration board. The spacing angles between the marked feature points are known. The forms of the calibration board (2) include checkerboard, dot board or coded disk; The calibration board coordinate system is defined as follows: Place the calibration board coordinate system at the pattern center of the feature marker. After defining the calibration board coordinate system, determine the coordinate positions (x cali , y cali , z cali ) of the marker feature points in the calibration board coordinate system (201) according to the spacing angles between the marker feature points, where i represents the number of feature points; The coordinates of the reprojection points of the calibration feature points in the pixel coordinate system (301) are calculated by the following formula:

6. The multi-module integrated calibration method for a laser mass transfer system according to claim 1, characterized in that The specific content of step S5 is as follows: The image processing algorithm for the marker image is selected according to the feature point shape of the selected feature marker, including a dot detection algorithm, a corner point detection algorithm, or a template matching algorithm, and its purpose is to extract the coordinates A of the feature points in the pixel coordinate system (301). i (u i ,v i ).

7. A multi-module integrated calibration method for a laser mass transfer system according to claim 1, characterized in that, The specific content of step S6 is as follows: The minimization of the reprojection error function using the least squares method is specifically: Where A is the coordinate of the feature point in the pixel coordinate system, A' is the coordinate of the feature point reprojected into the pixel coordinate system, M is the camera internal parameter, D is the camera distortion parameter, ρ is the system kinematic parameter, m is the number of poses of the precision motion platform for displacement, and n is the number of checkerboard corner points used for calculation; The nonlinear optimization adopts the Levenberg-Marquardt algorithm, sets the iterative convergence threshold, and the optimization result converges quickly to minimize the overall error.

8. A system, characterized in that, It includes a calibration module that can run a multi-module integrated calibration method for a laser mass transfer system according to any one of claims 1-7.

9. An apparatus, characterized in that, It includes: A memory: used to store a computer program for implementing a multi-module integrated calibration method for a laser mass transfer system according to any one of claims 1-7; Processor: When executing the computer program, it is used to implement the above multi-module integrated calibration method for a laser mass transfer system.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the multi-module integrated calibration method for a laser mass transfer system according to any one of claims 1-7.

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