A coordinate system transmission method in a robot welding process based on machine vision

Abstract

The application provides a coordinate system transmission method in a robot welding process based on machine vision, an addressing work station photographs a target object through a camera, and models a mark point posture on the target object to obtain a coordinate of the target object relative to a mark point coordinate system; an offset angle of a target object coordinate system and a servo coordinate system aligns the target object coordinate system with the servo coordinate system; the target object after the coordinate system alignment stores a coordinate with the main mark point as the origin to a database for a welding work station to request data; the welding work station photographs the mark point through the camera, and the target object is positioned in a robot coordinate system; an offset angle of the target object coordinate system and the robot coordinate system aligns the target object coordinate system with the robot coordinate system; the target point coordinate data of the addressing work station is requested; a galvanometer, a camera and a robot are jointly calibrated; the target point coordinate of the addressing work station is converted to the target point coordinate of the welding work station; the target point coordinate of the welding work station is converted to the galvanometer coordinate system, and the target point is positioned for welding.

Description

Technical Field

[0001] This invention relates to the field of robotic laser welding technology, and more particularly to a coordinate system transfer method in the robotic welding process based on machine vision. Background Technology

[0002] Currently, in the field of robotic laser welding, the introduction of machine vision technology can effectively improve welding accuracy. Compared to traditional welding that relies on mechanical positioning, machine vision technology can dynamically reduce nonlinear errors generated during the welding process, thereby improving welding accuracy.

[0003] However, due to technological limitations, the welding process is divided into two workstations: an addressing station and a welding station. These two stations use different coordinate systems, raising the question of how to transfer these coordinate systems. To address this issue, it is crucial to solve the problem of how to efficiently and accurately improve the efficiency of vision-guided laser welding. Summary of the Invention

[0004] The present invention aims to provide a coordinate system transfer method in the robotic welding process based on machine vision, so as to overcome the shortcomings of the prior art.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a coordinate system transfer method in a robot welding process based on machine vision, comprising the following steps:

[0006] Step 1: The addressing station drives the camera to take pictures of the target object through the servo mechanism, and uses the marker points on the target object to model its posture and obtain the coordinates of the target object relative to the main marker point coordinate system. The marker points include the main marker point and the auxiliary marker point.

[0007] Step 2: Calculate the offset angle between the target coordinate system and the servo coordinate system, and eliminate the angle to align the target coordinate system with the servo coordinate system.

[0008] Step 3: Calculate the actual coordinates of the target object after coordinate system one, with the main marker point as the origin, and store them in the database for the welding station to request data.

[0009] Step 4: The welding station uses a robot to drive a camera to take pictures of the marker points and locate the target object in the robot coordinate system.

[0010] Step 5: Calculate the offset angle between the target coordinate system and the robot coordinate system, and eliminate the angle to align the target coordinate system with the robot coordinate system.

[0011] Step 6: Request the coordinate data of the target point of the addressing station;

[0012] Step 7: Obtain the joint calibration of the galvanometer, camera, and robot;

[0013] Step 8: Obtain the conversion relationship between the target point of the addressing station and the target point of the welding station, and convert the coordinates of the target point of the addressing station to the coordinates of the target point of the welding station;

[0014] Step 9: Transform the coordinates of the target point in the welding station to the galvanometer coordinate system and perform target point positioning welding.

[0015] As an improvement to the coordinate system transfer method in the robot welding process based on machine vision according to the present invention, step 2, calculating the offset angle between the target object coordinate system and the servo coordinate system includes the following steps:

[0016] Step 201: Move the camera directly above the main marker point using the servo mechanism, record the coordinates of the servo mechanism at this time, take a picture, and calculate the image coordinates of the main marker point in the acquired image.

[0017] Step 202: Move the camera directly above the auxiliary marker point using the servo mechanism, record the coordinates of the servo mechanism at this time, take a picture, and calculate the image coordinates of the auxiliary marker point in the acquired image.

[0018] Step 203: Using the image coordinates of the main and auxiliary marker points and the servo camera position coordinates obtained in steps 201 to 202, calculate the offset angle based on the angle between the line connecting the main and auxiliary marker points and the two rays in the same horizontal direction as the main marker point and the servo coordinate system.

[0019] As an improvement to the coordinate system transfer method in the robot welding process based on machine vision according to the present invention, step 3, calculating the actual coordinates of the target object after addressing the workstation coordinate system includes the following steps.

[0020] Step 301: Record the servo coordinates and image coordinates of the camera at the main marker point;

[0021] Step 302: Record the servo coordinates and image coordinates of the camera at the welding target point;

[0022] Step 303: Calculate the distance between the welding target point and the main marker point, and correct the distance using the angle calculated in step 203.

[0023] As an improvement to the coordinate system transfer method in the robot welding process based on machine vision according to the present invention, step 5, calculating the offset angle between the target object coordinate system and the robot coordinate system includes the following steps:

[0024] Step 501: Move the camera directly above the main marker point using the robot, record the camera's coordinates in the robot's coordinate system at this time, and calculate the image coordinates of the main marker point;

[0025] Step 502: Move the camera directly above the auxiliary marker point using the robot, record the camera's coordinates in the robot's coordinate system at this time, and calculate the image coordinates of the auxiliary marker point.

[0026] Step 503: Using the image coordinates of the main and auxiliary marker points and the robot's photo-taking position coordinates obtained in steps 501 and 502, calculate the offset angle based on the angle between the line connecting the main and auxiliary marker points and the two rays in the same horizontal direction as the main marker point and the robot coordinate system.

[0027] As an improvement to the coordinate system transfer method in the robot welding process based on machine vision according to the present invention, the calculation of the coordinates of the welding target point in the laser galvanometer coordinate system in steps 6 to 9 includes the following steps:

[0028] Step S1: Calculate the addressing station data to obtain the coordinates with the main marker point as the origin of the coordinate system;

[0029] Step S2: Calculate the coordinates of the main marker point in the robot coordinate system using the transformation matrix between the robot and the camera. The calculation formula is as follows:

[0030] (x C0 ,y C0 )[M1]+(x0,y0)=(x R0 ,y R0 )

[0031] Where (x) C0 ,y C0 M1 is the coordinate value of the main marker point in the camera image coordinate system, M2 is the transformation matrix of the camera where the main marker point is located, and (x0, y0) is the coordinate value of the camera point in the robot coordinate system where the camera takes the picture. R0 ,y R0 () represents the absolute coordinates of the main marker point in the robot coordinate system;

[0032] The steps for calculating the transformation matrix M1 are as follows:

[0033] Step S21: Open the camera at the determined shooting height, mark the center of the camera's field of view, record the robot's coordinates (X1, Y1) at this time, and mark the image number as 1;

[0034] Step S22: Move the robot a certain distance along its positive and negative X and Y axes. Take an image at each position and record the robot's coordinates and the corresponding image number. A total of 8 sets of coordinates and images are recorded as (X2,Y2)……(X9,Y9), and the image numbers are marked as 2-9.

[0035] Step S23: Calculate the image coordinates of the marker points in each image to obtain a total of 9 sets of image coordinates, denoted as (R1,C1)……(R9,C9);

[0036] Step S24: Calculate the transformation matrix M1 using the obtained 9 sets of image coordinates (R1, C1) to (R9, C9) and 9 sets of robot coordinates (X1, Y1) to (X9, Y9). Note the coordinate relationships; they correspond one-to-one according to the sequence numbers. The calculation formula is as follows:

[0037] M1(R1,C1)=(X1,Y1)

[0038] M1 can then be obtained;

[0039] Step S3: Calculate the coordinates of the welding target point in the robot coordinate system based on steps S1 and S2;

[0040] Step S4: Calculate the extrinsic parameter matrix of the galvanometer in the robot coordinate system using the 9-point calibration of the galvanometer coordinate system and the robot coordinate system;

[0041] Step S5: Calculate the transformation matrix between the target object and the galvanometer coordinate system using the extrinsic parameter matrix between the robot, camera, and galvanometer.

[0042] Step S6: Use the transformation matrix obtained in step S5 to change the coordinate system of the addressing station to the coordinate system of the welding station galvanometer.

[0043] Step S7: Calculate the coordinates of the target object in the galvanometer coordinate system of the welding station.

[0044] The calculation formula is as follows:

[0045] M2(X R ,Y R )=(X Z ,Y Z )

[0046] Where (X) R ,Y R (X) represents the coordinates of the target object in the robot coordinate system. Z ,Y Z ) represents the coordinates of the target object in the galvanometer coordinate system.

[0047] As an improvement to the coordinate system transfer method in the robot welding process based on machine vision according to the present invention, in step S4, the transformation matrix of the galvanometer in the robot coordinate system is calculated using the 9-point calibration of the galvanometer coordinate system and the robot coordinate system. The steps are as follows.

[0048] Step S41: At the standard welding height, keep the robot stationary, use a galvanometer to emit light and offset coordinates to burn nine marked points. The center point is the galvanometer's 0 position for light emission. The other eight points are shifted a certain distance in the positive and negative directions along the galvanometer's X and Y axes, respectively. Record the galvanometer coordinates and order of the nine points. Z1 ,YZ1 )......(X Z9 ,Y Z9 It is best to label the corresponding solder joint with a serial number, and at the same time record the actual coordinates (X, Y, Z) of the current robot. R ,Y R );

[0049] Step S42: Keeping the welding standard plate stationary, move the robot to position the camera directly above its center. The crosshair at the center of the camera's field of view should be aligned with the welding center point to take a picture. The picture height should be consistent with the camera calibration time. Record the robot's photo coordinates (X...) at this point. C ,Y C The system identifies the image coordinates of nine welding points in the image and obtains their corresponding robot coordinates (X1, Y1) to (X9, Y9) through the calibration relationship between the camera and the robot.

[0050] Step S43: Using the nine coordinates of the galvanometer and the corresponding identified robot coordinates as input, generate transformation matrix M2. Note the coordinate correspondence; use the coordinate difference to perform the transformation, that is, use (X1-X... C ,Y1-Y C )......(X9-X C ,Y9-Y C As robot coordinates are calculated, the calculation method is as follows:

[0051] M2(X1-X C ,Y1-Y C )=(X Z1 ,Y Z1 )

[0052] M2 can then be obtained.

[0053] As an improvement to the coordinate system transfer method in the robot welding process based on machine vision according to the present invention, in step S41, the distance of positive and negative translation of the marker point exceeds 1 / 3 of the camera's field of view.

[0054] Compared with the prior art, the beneficial effects of the present invention are:

[0055] 1. This invention solves the problem of inconsistent coordinate systems between the addressing station and the welding station. It uses the module coordinate system as the transfer system to transfer the coordinates of the target object in the addressing station to the coordinate system of the welding station, and then performs coordinate transformation to complete the positioning welding.

[0056] 2. Compared to traditional methods that select multiple points and use the least squares method to fit a straight line to obtain the angle between coordinate systems, this invention uses two straight lines formed by four marker points on the object. This allows for a more efficient calculation of the angle between coordinate systems, and the relevant accuracy meets practical requirements. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 This is a flowchart of the addressing workstation of the present invention;

[0059] Figure 2 This is a flowchart of the welding station of the present invention;

[0060] Figure 3 A schematic diagram showing the angular deviation between the original servo coordinate system and the target object coordinate system;

[0061] Figure 4 A schematic diagram illustrating the elimination of angular deviation between the servo coordinate system and the target coordinate system.

[0062] Figure 5 A schematic diagram showing the angular deviation between the original robot coordinate system and the target object coordinate system;

[0063] Figure 6 A schematic diagram illustrating the elimination of angular deviations between the robot coordinate system and the target object coordinate system;

[0064] Figure 7 A schematic diagram showing the angle between the line connecting the main and auxiliary markers and the two rays that run in the same direction as the main marker and the servo coordinate system.

[0065] Figure 8 A schematic diagram illustrating the calculation of the coordinates of the auxiliary marker and the main marker in the same image coordinate system;

[0066] Figure 9 A schematic diagram showing the angle between the line connecting the main and auxiliary markers and the two rays that run in the same direction as the main marker and the robot coordinate system.

[0067] Figure 10 This is a schematic diagram for calculating the coordinates of the auxiliary marker and the main marker in the same image coordinate system. Detailed Implementation

[0068] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0069] like Figures 1 to 6As shown, a coordinate system transfer method in the robot welding process based on machine vision includes the following steps: Step 1, the addressing station drives the camera to take pictures of the target object through the servo mechanism, and uses the marker points on the target object to model its posture to obtain the coordinates of the target object relative to the main marker point coordinate system, wherein the marker points include the main marker point and the auxiliary marker point.

[0070] Step 2: Calculate the offset angle between the target coordinate system and the servo coordinate system, and eliminate the angle to align the target coordinate system with the servo coordinate system.

[0071] In step 2, calculating the offset angle between the target coordinate system and the servo coordinate system includes the following steps:

[0072] Step 201: Move the camera directly above the main marker point using the servo mechanism, record the coordinates of the servo mechanism at this time, take a picture, and calculate the image coordinates of the main marker point in the acquired image.

[0073] Step 202: Move the camera directly above the auxiliary marker point using the servo mechanism, record the coordinates of the servo mechanism at this time, take a picture, and calculate the image coordinates of the auxiliary marker point in the acquired image.

[0074] refer to Figure 7 and Figure 8 Step 203: Using the image coordinates of the main and auxiliary marker points and the servo camera position coordinates obtained in steps 201 to 202, the offset angle is calculated based on the angle between the line connecting the main and auxiliary marker points and the two rays in the same horizontal direction as the main marker point and the servo coordinate system, as follows:

[0075] Let the coordinates of the Mark (main) image be (R1, C1), and the servo capture position be (X1, Y1).

[0076] Mark (auxiliary) image coordinates: (R2, C2), servo capture position (X2, Y2),

[0077] Pixel equivalent: Acc, Camera difference: ΔCam;

[0078] Objective: Calculate the coordinates of the main and auxiliary marker points in the same image coordinate system: (R1', C1') and (R2', C2');

[0079] To transform the auxiliary markers to the image coordinate system of the main marker, i.e., R1' = R1, C1' = C1, we only need to calculate (R2', C2'). The steps for calculating (R2', C2') are as follows:

[0080] Actual distance difference: (C2-C1)Acc;

[0081] Servo-controlled image position difference: ΔX = X2 - X1;

[0082] Auxiliary Mark point image coordinates: C2'=C2+(ΔX+ΔCam) / Acc;

[0083] Similarly, R2' = R2 + (ΔY + ΔCam) / Acc.

[0084] Step 3: Calculate the actual coordinates of the target object after coordinate system one, with the main marker point as the origin, and store them in the database for the welding station to request data.

[0085] In step 3, calculating the actual coordinates of the target object after establishing the addressing station coordinate system includes the following steps.

[0086] Step 301: Record the servo coordinates and image coordinates of the camera at the main marker point;

[0087] Step 302: Record the servo coordinates and image coordinates of the camera at the welding target point;

[0088] Step 303: Calculate the distance between the welding target point and the main marker point, and correct the distance using the angle calculated in Step 1.

[0089] Step 4: The welding station uses a robot to drive a camera to take pictures of the marker points and locate the target object in the robot coordinate system.

[0090] Step 5: Calculate the offset angle between the target coordinate system and the robot coordinate system, and eliminate the angle to align the target coordinate system with the robot coordinate system.

[0091] In step 5, calculating the offset angle between the target coordinate system and the robot coordinate system includes the following steps:

[0092] Step 501: Move the camera directly above the main marker point using the robot, record the camera's coordinates in the robot's coordinate system at this time, and calculate the image coordinates of the main marker point;

[0093] Step 502: Move the camera directly above the auxiliary marker point using the robot, record the camera's coordinates in the robot's coordinate system at this time, and calculate the image coordinates of the auxiliary marker point.

[0094] refer to Figure 9 and Figure 10 Step 503: Using the image coordinates of the main and auxiliary marker points and the robot's photographing position coordinates obtained in steps 501 and 502, the offset angle is calculated based on the angle between the line connecting the main and auxiliary marker points and the two rays in the same horizontal direction as the main marker point and the robot coordinate system.

[0095] Let the coordinates of the Mark (main) image be (R1, C1), and the robot's image position be (X1, Y1).

[0096] Mark (auxiliary) image coordinates: (R2, C2), robot image position (X2, Y2),

[0097] Pixel equivalent: Acc, Camera difference: ΔCam;

[0098] Objective: Calculate the coordinates of the main and auxiliary landmarks in the same image coordinate system: (R1', C1') and (R2', C2');

[0099] To transform the auxiliary markers to the image coordinate system of the main marker, i.e., R1' = R1, C1' = C1, we only need to calculate (R2', C2'). The steps for calculating (R2', C2') are as follows:

[0100] Actual distance difference: (C2-C1)Acc;

[0101] Robot's positional difference in taking photos: ΔX = X2 - X1;

[0102] Auxiliary Mark point image coordinates: C2'=C2+(ΔX+ΔCam) / Acc;

[0103] Similarly, R2' = R2 + (ΔY + ΔCam) / Acc.

[0104] Step 6: Request the coordinate data of the target point of the addressing station;

[0105] Step 7: Obtain the joint calibration of the galvanometer, camera, and robot;

[0106] Step 8: Obtain the conversion relationship between the target point of the addressing station and the target point of the welding station, and convert the coordinates of the target point of the addressing station to the coordinates of the target point of the welding station;

[0107] Step 9: Transform the coordinates of the target point in the welding station to the galvanometer coordinate system and perform target point positioning welding.

[0108] In steps 6 to 9, calculating the coordinates of the welding target point in the laser galvanometer coordinate system includes the following steps:

[0109] Step S1: Calculate the addressing station data to obtain the coordinates with the main marker point as the origin of the coordinate system;

[0110] Step S2: Calculate the coordinates of the main marker point in the robot coordinate system using the transformation matrix between the robot and the camera. The calculation formula is as follows:

[0111] (x C0 ,y C0 )[M1]+(x0,y0)=(x R0 ,y R0 )

[0112] Where (x) C0 ,yC0 M1 is the coordinate value of the main marker point in the camera image coordinate system, M2 is the transformation matrix of the camera where the main marker point is located, and (x0, y0) is the coordinate value of the camera point in the robot coordinate system where the camera takes the picture. R0 ,y R0 () represents the absolute coordinates of the main marker point in the robot coordinate system;

[0113] The steps for calculating the transformation matrix M1 are as follows:

[0114] Step S21: Open the camera at the determined shooting height, mark the center of the camera's field of view, record the robot's coordinates (X1, Y1) at this time, and mark the image number as 1;

[0115] Step S22: Move the robot a certain distance along its positive and negative X and Y axes. Take an image at each position and record the robot's coordinates and the corresponding image number. A total of 8 sets of coordinates and images are recorded as (X2,Y2)……(X9,Y9), and the image numbers are marked as 2-9.

[0116] Step S23: Calculate the image coordinates of the marker points in each image to obtain a total of 9 sets of image coordinates, denoted as (R1,C1)……(R9,C9);

[0117] Step S24: Calculate the formula using the obtained 9 sets of image coordinates (R1, C1) to (R9, C9) and 9 sets of robot coordinates (X1, Y1) to (X9, Y9):

[0118] M1(R1,C1)=(X1,Y1)

[0119] M1 can then be obtained.

[0120] Step S3: Calculate the coordinates of the welding target point in the robot coordinate system based on steps S1 and S2;

[0121] Step S4: Calculate the extrinsic parameter matrix of the galvanometer in the robot coordinate system using the 9-point calibration of the galvanometer coordinate system and the robot coordinate system;

[0122] In step S4, the transformation matrix of the galvanometer in the robot coordinate system is calculated using the 9-point calibration between the galvanometer coordinate system and the robot coordinate system. The steps are as follows:

[0123] Step S41: At the standard welding height, keep the robot stationary, use a galvanometer to emit light and offset coordinates to burn nine marked points. The center point is the galvanometer's 0 position for light emission. The other eight points are shifted a certain distance in the positive and negative directions along the galvanometer's X and Y axes, respectively. Record the galvanometer coordinates and order of the nine points. Z1 ,Y Z1 )......(X Z9,Y Z9 It is best to label the corresponding solder joint with a serial number, and at the same time record the actual coordinates (X, Y, Z) of the current robot. R ,Y R );

[0124] Step S42: Keeping the welding standard plate stationary, move the robot to position the camera directly above its center. The crosshair at the center of the camera's field of view should be aligned with the welding center point to take a picture. The picture height should be consistent with the camera calibration time. Record the robot's photo coordinates (X...) at this point. C ,Y C The system identifies the image coordinates of nine welding points in the image and obtains their corresponding robot coordinates (X1, Y1) to (X9, Y9) through the calibration relationship between the camera and the robot.

[0125] Step S43: Using the nine coordinates of the galvanometer and the corresponding identified robot coordinates as input, generate transformation matrix M2. Note the coordinate correspondence; use the coordinate difference to perform the transformation, that is, use (X1-X... C ,Y1-Y C )......(X9-X C ,Y9-Y C As robot coordinates are calculated, the calculation method is as follows:

[0126] M2(X1-X C ,Y1-Y C )=(X Z1 ,Y Z1 )

[0127] M2 can then be obtained.

[0128] In step S41, the distance the marker point is translated in both the positive and negative directions exceeds 1 / 3 of the camera's field of view.

[0129] Step S5: Calculate the transformation matrix between the target object and the galvanometer coordinate system using the extrinsic parameter matrix between the robot, camera, and galvanometer.

[0130] Step S6: Use the transformation matrix obtained in step S5 to change the coordinate system of the addressing station to the coordinate system of the welding station galvanometer.

[0131] Step S7: Calculate the coordinates of the target object in the galvanometer coordinate system of the welding station.

[0132] The calculation formula is as follows:

[0133] M2(X R ,Y R )=(X Z ,Y Z )

[0134] Where (X) R ,YR (X) represents the coordinates of the target object in the robot coordinate system. Z ,Y Z ) represents the coordinates of the target object in the galvanometer coordinate system.

[0135] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0136] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A coordinate system transfer method in a robot welding process based on machine vision, characterized in that, Includes the following steps, Step 1: The addressing station drives the camera to take pictures of the target object through the servo mechanism, and uses the marker points on the target object to model its posture and obtain the coordinates of the target object relative to the main marker point coordinate system. The marker points include the main marker point and the auxiliary marker point. Step 2: Calculate the offset angle between the target coordinate system and the servo coordinate system, and eliminate the angle to align the target coordinate system with the servo coordinate system. Step 3: Calculate the actual coordinates of the target object after coordinate system one, with the main marker point as the origin, and store them in the database for the welding station to request data. Step 4: The welding station uses a robot to drive a camera to take pictures of the marker points and locate the target object in the robot coordinate system. Step 5: Calculate the offset angle between the target coordinate system and the robot coordinate system, and eliminate the angle to align the target coordinate system with the robot coordinate system. Step 6: Request the coordinate data of the target point of the addressing station; Step 7: Obtain the joint calibration of the galvanometer, camera, and robot; Step 8: Obtain the conversion relationship between the target point of the addressing station and the target point of the welding station, and convert the coordinates of the target point of the addressing station to the coordinates of the target point of the welding station; Step 9: Transform the coordinates of the target point in the welding station to the galvanometer coordinate system and perform target point positioning welding.

2. The coordinate system transfer method in a robot welding process based on machine vision according to claim 1, characterized in that, Step 2, calculating the offset angle between the target coordinate system and the servo coordinate system includes the following steps: Step 201: Move the camera directly above the main marker point using the servo mechanism, record the coordinates of the servo mechanism at this time, take a picture, and calculate the image coordinates of the main marker point in the acquired image. Step 202: Move the camera directly above the auxiliary marker point using the servo mechanism, record the coordinates of the servo mechanism at this time, take a picture, and calculate the image coordinates of the auxiliary marker point in the acquired image. Step 203: Using the image coordinates of the main and auxiliary marker points and the servo camera position coordinates obtained in steps 201 to 202, calculate the offset angle based on the angle between the line connecting the main and auxiliary marker points and the two rays in the same horizontal direction as the main marker point and the servo coordinate system.

3. The coordinate system transfer method in a robot welding process based on machine vision according to claim 1, characterized in that, In step 3, calculating the actual coordinates of the target object after the addressing station coordinate system is established includes the following steps: Step 301: Record the servo coordinates and image coordinates of the camera at the main marker point; Step 302: Record the servo coordinates and image coordinates of the camera at the welding target point; Step 303: Calculate the distance between the welding target point and the main marker point, and correct the distance using the angle calculated in step 203.

4. The coordinate system transfer method in a robot welding process based on machine vision according to claim 1, characterized in that, Step 5 involves calculating the offset angle between the target coordinate system and the robot coordinate system, including the following steps: Step 501: Move the camera directly above the main marker point using the robot, record the camera's coordinates in the robot's coordinate system at this time, and calculate the image coordinates of the main marker point; Step 502: Move the camera directly above the auxiliary marker point using the robot, record the camera's coordinates in the robot's coordinate system at this time, and calculate the image coordinates of the auxiliary marker point. Step 503: Using the image coordinates of the main and auxiliary marker points and the robot's photo-taking position coordinates obtained in steps 501 and 502, calculate the offset angle based on the angle between the line connecting the main and auxiliary marker points and the two rays in the same horizontal direction as the main marker point and the robot coordinate system.

5. The coordinate system transfer method in a robot welding process based on machine vision according to claim 1, characterized in that, In steps 6 to 9, calculating the coordinates of the welding target point in the laser galvanometer coordinate system includes the following steps: Step S1: Calculate the addressing station data to obtain the coordinates with the main marker point as the origin of the coordinate system; Step S2: Calculate the coordinates of the main marker point in the robot coordinate system using the transformation matrix between the robot and the camera. The calculation formula is as follows: ； in The coordinates of the main marker point in the camera image coordinate system. The transformation matrix of the camera where the main marker is located. These are the coordinates of the camera's image capture point in the robot's coordinate system. The absolute coordinates of the main marker point in the robot coordinate system; Where, transformation matrix The calculation steps are as follows: Step S21: Open the camera at the determined shooting height, mark the center of the camera's field of view, and record the robot's coordinates at this time. The image number is marked as 1; Step S22: Move the robot a certain distance along its positive and negative X and Y axes, capturing an image at each location and recording the robot's coordinates and corresponding image number. A total of 8 sets of coordinates and images are recorded. ...... The image numbers are marked as 2-9; Step S23: Calculate the image coordinates of the marker points in each image, resulting in a total of 9 sets of image coordinates, denoted as... ...... ; Step S24, using the obtained 9 sets of image coordinates to and 9 sets of robot coordinates to Calculate the transformation matrix Note the coordinate relationship, and follow the one-to-one correspondence according to the serial number, based on the calculation formula: ； You can get ; Step S3: Calculate the coordinates of the welding target point in the robot coordinate system based on steps S1 and S2; Step S4: Calculate the extrinsic parameter matrix of the galvanometer in the robot coordinate system using the 9-point calibration of the galvanometer coordinate system and the robot coordinate system; Step S5: Calculate the transformation matrix between the target object and the galvanometer coordinate system using the extrinsic parameter matrix between the robot, camera, and galvanometer. Step S6: Use the transformation matrix obtained in step S5 to change the coordinate system of the addressing station to the coordinate system of the welding station galvanometer. Step S7: Calculate the coordinates of the target object in the galvanometer coordinate system of the welding station; The calculation formula is as follows: ； in The coordinates of the target object in the robot's coordinate system. The coordinates of the target object in the galvanometer coordinate system; Let be the transformation matrix of the galvanometer in the robot coordinate system.

6. The coordinate system transfer method in a robot welding process based on machine vision according to claim 5, characterized in that, In step S4, the transformation matrix of the galvanometer in the robot coordinate system is calculated using the 9-point calibration between the galvanometer coordinate system and the robot coordinate system. The steps are as follows: Step S41: At the standard welding height, keeping the robot stationary, use a galvanometer to emit light and offset coordinates to burn nine marked points. The center point is the galvanometer's 0 position. The other eight points are shifted a certain distance in the positive and negative directions along the galvanometer's X and Y axes, respectively. Record the galvanometer coordinates and their order for the nine points. ...... Mark the serial number next to the corresponding welding point, and record the actual coordinates of the robot at the same time; Step S42: Keeping the welding standard plate stationary, move the robot to position the camera directly above its center. The camera's field of view should be aligned with the center of the welding point to take a picture. The picture height should be consistent with the camera's calibration. Record the robot's photo coordinates at this point. The image coordinates of nine welding points in the image were identified, and their corresponding robot coordinates were obtained through the calibration relationship between the camera and the robot. To coordinates ; Step S43: Using the nine coordinates of the galvanometer and the corresponding identified robot coordinates as input, generate a transformation matrix. Note the coordinate correspondence; use coordinate differences to perform transformations, that is, use... ...... For robot coordinate calculation, the calculation method is as follows: ； You can get .

7. The coordinate system transfer method in a robot welding process based on machine vision according to claim 6, characterized in that, In step S41, the distance the marker point is translated in both the positive and negative directions exceeds 1 / 3 of the camera's field of view.

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