A laser weld seam tracking device and a laser weld seam tracking method

Abstract

The application discloses a laser weld seam tracking device and a laser weld seam tracking method. The laser weld seam tracking device comprises a six-axis welding robot, a laser weld seam tracking sensor, a first angle adjusting mechanism, a second angle adjusting mechanism and a control mechanism. The driving end of the six-axis welding robot is provided with a welding gun. The laser weld seam tracking sensor is arranged at the front end of the welding gun. The first angle adjusting mechanism is arranged on one side of the laser weld seam tracking sensor. The second angle adjusting mechanism is arranged on one side of the laser weld seam tracking sensor. Through the double-degree-of-freedom servo self-adaptive angle adjusting structure, the posture of the laser weld seam tracking sensor is dynamically and self-adaptively adjusted according to the weld seam curvature, the problems of laser stripe loss, imaging distortion and tracking failure under the working conditions of curved surfaces, corners and variable-curvature weld seams are solved, the tracking precision and stability of complex special-shaped weld seams are improved, and the operation and maintenance cost and the debugging cost are reduced.

Description

Technical Field

[0001] This application relates to the field of laser welding technology, and in particular to a laser weld seam tracking device and a laser weld seam tracking method. Background Technology

[0002] Laser weld seam tracking technology is widely used in the field of automated welding. By using laser sensors to identify the weld seam groove shape, it can realize weld seam positioning and real-time tracking, effectively improving welding accuracy and production efficiency.

[0003] Most existing laser weld seam tracking devices adopt a fixed angle-adjusting structure, which can only adapt to standard weld seam conditions such as regular straight lines and planes. In the case of curved surfaces, corners, and weld seams with high curvature, laser stripe loss, imaging distortion, and tracking failure will occur; the tracking accuracy and stability are poor. At the same time, for workpieces with different curvatures and different welding postures, the installation angle of the laser weld seam tracking sensor needs to be manually adjusted, resulting in high operation and maintenance costs and debugging costs. Summary of the Invention

[0004] The purpose of this application is to provide a laser weld seam tracking device and a laser weld seam tracking method to improve the problems of missing laser stripes, imaging distortion, tracking failure, low tracking accuracy, poor stability, high operation and maintenance costs, and high debugging costs.

[0005] This invention discloses a laser weld seam tracking device, which adopts the following technical solution: A laser weld seam tracking device includes a six-axis welding robot, a laser weld seam tracking sensor, a first angle adjustment mechanism, a second angle adjustment mechanism, and a control mechanism. The six-axis welding robot has a welding torch mounted on its drive end, and is used at least to drive the welding torch to move for welding workpieces. The laser weld seam tracking sensor is mounted on the welding torch and is used at least to acquire bevel contour images, calculate weld seam position deviations, calculate bevel curvature and bevel cross-sectional tilt angles, and for locating and tracking weld seams. The first angle adjustment mechanism is located on one side of the laser weld seam tracking sensor and is used at least to adjust the pitch angle of the laser weld seam tracking sensor. The second angle adjustment mechanism is located on one side of the laser weld seam tracking sensor and is used at least to adjust the horizontal swing angle of the laser weld seam tracking sensor. The six-axis welding robot, the laser weld seam tracking sensor, the first angle adjustment mechanism, and the second angle adjustment mechanism are all electrically connected to the control mechanism.

[0006] By adopting the above technical solution and using a dual-degree-of-freedom servo adaptive angle adjustment structure, the attitude of the laser weld seam tracking sensor is dynamically and adaptively adjusted according to the curvature of the weld seam. This effectively solves the problems of laser stripe loss, imaging distortion, and tracking failure of traditional fixed-angle sensors under curved surface, corner, and variable curvature weld seam conditions, significantly improving the tracking accuracy and stability of complex irregular weld seams. At the same time, it reduces the process of manually adjusting the installation angle of the laser weld seam tracking sensor, reducing operation and maintenance costs and debugging costs. This makes the laser weld seam tracking equipment adaptable to flexible welding production of various types and irregular workpieces, with a wider range of applicable scenarios.

[0007] Optionally, the laser weld seam tracking sensor includes a housing, inside which are disposed an industrial camera, a lens, a line laser emitter, and a drive circuit board, the industrial camera, the line laser emitter, and the drive circuit board being electrically connected; the industrial camera is used to receive bevel laser stripe images and acquire bevel contour images; the line laser emitter is used to emit a line-shaped laser.

[0008] By adopting the above technical solution, the line laser emitter is used to project a linear laser beam onto the bevel of the workpiece. The industrial camera is used to receive the laser stripe image reflected from the bevel and to acquire the bevel contour image. The controller on the circuit board calculates the weld position deviation, the bevel curvature, and the bevel cross-sectional tilt angle, and is used to locate and track the weld.

[0009] Optionally, each joint of the six-axis welding robot is equipped with a joint encoder, which is used at least to acquire the actual rotation angle of the joints of the six-axis welding robot, and the controller of the six-axis welding robot is used at least to acquire the welding torch pose.

[0010] By adopting the above technical solution, the joint encoder can acquire the actual rotation angle of the joints of the six-axis welding robot, and the controller of the six-axis welding robot can calculate and obtain the real-time pose of the welding torch and the welding travel speed. This enables the linkage control of weld morphology parameters and robot motion parameters, providing an accurate data foundation for multi-dimensional attitude and speed advance compensation of the equipment. It effectively improves the problems of lag in attitude adjustment and tracking jitter of the laser weld seam tracking sensor during high-speed or variable curvature welding. Simultaneously, it can predict the relative position of the welding torch and the laser weld seam tracking sensor, avoiding interference and collisions, significantly improving weld seam tracking accuracy and the safety and stability of equipment operation.

[0011] Optionally, a narrowband filter is provided on the camera in front of the lens. The narrowband filter is used to filter out welding arc light, spatter light and ambient light to reduce interference from welding light.

[0012] By adopting the above technical solution, the narrowband filter is used to filter out welding arc light, spatter light and ambient stray light, so as to reduce the interference of welding light and improve the recognition accuracy.

[0013] Optionally, the first angle adjustment mechanism includes a first servo motor, a worm gear is fixedly connected to the drive end of the first servo motor, a worm wheel is meshed with one side of the worm gear, a support seat is provided on one side of the worm wheel, the support seat rotates with the worm wheel, and the laser weld seam tracking sensor is fixedly mounted on the support seat.

[0014] By adopting the above technical solution, the rotation of the first servo motor drives the support base to rotate via a worm gear and worm shaft, thereby driving the laser weld seam tracking sensor to rotate and achieving real-time adjustment of the pitch angle of the laser weld seam tracking sensor. The worm gear and worm shaft have a self-locking function, which can precisely lock the angle after adjustment, preventing angle deviation caused by welding vibration and realizing precise adjustment of the pitch accuracy of the laser weld seam tracking sensor.

[0015] Optionally, a first angle feedback encoder is provided on the drive shaft of the first servo motor, and the first angle feedback encoder rotates with the first servo motor.

[0016] By adopting the above technical solution, the first angle feedback encoder can provide real-time feedback on the actual rotation angle of the first servo motor, forming an angle closed-loop correction, which can effectively compensate for the adjustment error of the first angle adjustment mechanism and greatly improve the adjustment accuracy and tracking stability of the laser weld seam tracking sensor in the vertical direction.

[0017] Optionally, the second angle adjustment mechanism includes a second servo motor, the drive end of the second servo motor is provided with a turntable, and the fixed end of the first servo motor is fixedly connected to the turntable.

[0018] Optionally, a second angle feedback encoder is provided on the drive shaft of the second servo motor, and the second angle feedback encoder rotates with the second servo motor.

[0019] By adopting the above technical solution, the second angle feedback encoder can provide real-time feedback on the actual rotation angle of the second servo motor, forming an angle closed-loop correction. This effectively compensates for the adjustment error of the second angle adjustment mechanism and significantly improves the adjustment accuracy and tracking stability of the laser weld seam tracking sensor in the horizontal direction.

[0020] Optionally, a protective cover is provided on the outside of the first angle adjustment mechanism and the second angle adjustment mechanism. The protective cover is used to prevent fumes and welding slag from splashing onto the first angle adjustment mechanism and the second angle adjustment mechanism.

[0021] By adopting the above technical solution, the protective cover is used to prevent smoke and welding slag from splashing onto the first angle adjustment mechanism and the second angle adjustment mechanism.

[0022] In another aspect, the present invention discloses a laser weld seam tracking method, based on a laser weld seam tracking device, the laser weld seam tracking method comprising the following steps: S1. Set the attitude threshold of the laser weld seam tracking sensor corresponding to different curvatures on the control mechanism; S2: The laser weld seam tracking sensor scans the weld seam to be welded and obtains the real-time curvature of the weld seam, the bevel inclination angle, the weld seam offset direction and deformation parameters. S3: The control mechanism calculates in real time the pitch angle and horizontal swing angle required by the laser weld seam tracking sensor; S4: The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to adjust the overall attitude of the laser weld seam tracking sensor according to the required pitch angle and horizontal swing angle. S5: The first angle feedback encoder and the second angle feedback encoder transmit the actual adjustment angle in real time. The control mechanism calculates the difference between the actual adjustment angle and the theoretical optimal angle. The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to compensate for the adjustment error.

[0023] By adopting the above technical solution, and combining the joint angles collected by the six-axis robot joint encoder, the welding torch pose and walking speed are calculated, and a multi-dimensional attitude database is constructed to achieve linkage control between weld morphology and robot motion state. The optimal attitude angle is dynamically calculated based on real-time bevel parameters, improving weld recognition accuracy. The dual-degree-of-freedom servo adaptive angle adjustment structure enables the laser weld tracking sensor's attitude to dynamically and adaptively adjust with the weld curvature, improving the tracking accuracy and stability of complex irregular welds and reducing maintenance and debugging costs. Combined with the welding torch walking speed, attitude advance prediction compensation effectively overcomes servo response lag defects and improves the problems of sensor attitude adjustment lag and laser stripe mismatch during high-speed welding. Simultaneously, dual-encoder angle closed-loop error correction is used to compensate for adjustment deviations in real time, improving attitude adjustment accuracy.

[0024] In summary, this application includes at least one of the following beneficial technical effects: 1. The laser weld seam tracking device provided by this invention, through a dual-degree-of-freedom servo adaptive angle adjustment structure, realizes the dynamic adaptive adjustment of the laser weld seam tracking sensor's attitude according to the weld seam curvature. This effectively solves the problems of laser stripe loss, imaging distortion, and tracking failure of traditional fixed-angle sensors under curved surface, corner, and variable curvature weld seam conditions, significantly improving the tracking accuracy and stability of complex irregular weld seams. At the same time, it reduces the process of manually adjusting the installation angle of the laser weld seam tracking sensor, reducing operation and maintenance costs and debugging costs. This makes the laser weld seam tracking device adaptable to flexible welding production of various types and irregularly shaped workpieces, with a wider range of applicable scenarios. 2. The present invention provides a laser weld seam tracking device, wherein the joint encoder can collect the actual rotation angle of each joint of the six-axis welding robot, and the controller of the six-axis welding robot can perform calculation to obtain the real-time pose and welding traveling speed of the welding torch. The device realizes the coordinated regulation of weld seam morphology parameters and robot motion parameters, provides an accurate data basis for multi-dimensional posture and advance speed compensation of the device, and can effectively improve the problems of hysteresis in posture adjustment and tracking jitter of the laser weld seam tracking sensor during high-speed or variable-curvature welding. Meanwhile, it can predict the relative position between the welding torch and the laser weld seam tracking sensor, avoid interference and collision, and significantly improve the weld seam tracking accuracy as well as the safety and stability of device operation; 3. The present invention provides a laser weld seam tracking device, wherein the narrowband filter is used to filter out welding arc light, strong spatter light and ambient stray light, so as to reduce the interference of strong welding light and improve the recognition accuracy; 4. The present invention provides a laser weld seam tracking device, wherein the worm gear and the worm have a self-locking function, which can accurately lock the angle after the adjustment is completed, prevent angle offset caused by welding vibration, and realize precise adjustment of the pitch accuracy of the laser weld seam tracking sensor; 5. The present invention provides a laser weld seam tracking device, wherein the angle feedback encoder can feed back the actual rotation angle of the angle adjustment mechanism in real time to form angle closed-loop correction, which can effectively make up for the adjustment error of the angle adjustment mechanism, and greatly improve the adjustment accuracy and tracking stability of the laser weld seam tracking sensor; 6. The present invention provides a laser weld seam tracking method, which collects joint angles in combination with the robot joint encoder, calculates and obtains the pose and traveling speed of the welding torch, constructs a multi-dimensional posture database, and realizes coordinated regulation of weld seam morphology and robot motion state. The method dynamically calculates the optimal posture angle according to the real-time groove parameters to improve the weld seam recognition accuracy; the two-degree-of-freedom servo adaptive angle adjustment structure realizes dynamic adaptive adjustment of the posture of the laser weld seam tracking sensor along with the weld seam curvature, improves the tracking accuracy and stability of complex special-shaped weld seams, and reduces operation and maintenance costs and commissioning costs; in combination with the traveling speed of the welding torch, the method performs posture advance prediction and compensation, effectively overcomes the defect of servo response lag, and improves the problems of sensor posture adjustment lag and laser stripe mismatch during high-speed welding. At the same time, the dual-encoder angle closed-loop error correction is used to compensate the adjustment deviation in real time, which improves the posture adjustment accuracy. Brief Description of the Drawings

[0025] Figure 1 is a front view of a laser weld seam tracking device provided in a typical embodiment of the present invention; Figure 2 is a schematic structural diagram of a first angle adjustment mechanism and a second angle adjustment mechanism provided in a typical embodiment of the present invention; Figure 3 is a flowchart of the laser weld seam tracking method of the first embodiment; Figure 4 This is a flowchart of the laser weld seam tracking method in Example 2; In the diagram: 1. Six-axis welding robot; 2. Welding torch; 3. Laser weld seam tracking sensor; 4. First angle adjustment mechanism; 5. Second angle adjustment mechanism; 6. Protective outer cover. First servo motor; 402, worm gear; 403, worm wheel; 404, support base; 501. Second servo motor; 502. Turntable. Detailed Implementation

[0026] The following is in conjunction with the appendix Figure 1 - Appendix Figure 4 This application will be described in further detail below.

[0027] This invention discloses a laser weld seam tracking device, with reference to... Figure 1 The system includes a six-axis welding robot 1, a laser weld seam tracking sensor 3, a first angle adjustment mechanism 4, a second angle adjustment mechanism 5, and a control mechanism. The six-axis welding robot 1 has a welding torch 2 at its drive end, and is used at least to drive the welding torch 2 to move and weld the workpiece. The laser weld seam tracking sensor 3 is mounted on the welding torch 2 and is used at least to acquire bevel contour images, calculate weld seam position deviations, calculate bevel curvature and bevel cross-sectional tilt angles, and to locate and track the weld seam. Specifically, the laser weld seam tracking sensor 3 includes a housing, inside which are an industrial camera, a lens, a line laser emitter, and a drive circuit board. The industrial camera, line laser emitter, and drive circuit board are electrically connected. The lens is mounted on the front end of the industrial camera and is part of the camera's imaging section. The line laser emitter projects a linear laser beam onto the workpiece bevel. The industrial camera receives the laser stripe image reflected from the bevel and acquires the bevel contour image.

[0028] The first angle adjustment mechanism 4 is disposed on one side of the laser weld seam tracking sensor 3, and the first angle adjustment mechanism 4 is used at least to adjust the pitch angle of the laser weld seam tracking sensor 3; specifically, as shown in... Figure 2As shown, the first angle adjustment mechanism 4 includes a first servo motor 401. A worm gear 402 is fixedly connected to the drive end of the first servo motor 401, and the worm gear 402 is rotatably connected to the outer protective cover. A worm wheel 403 is meshed with one side of the worm gear 402, and a support base 404 is provided on one side of the worm wheel 403. The support base 404 rotates with the worm wheel 403, and the laser weld seam tracking sensor 3 is fixedly mounted on the support base 404. The rotation of the first servo motor 401 drives the worm gear 402 to rotate, and the rotation of the worm gear 402 drives the meshed worm wheel 403 to rotate, thereby driving the support base 404 and the laser weld seam tracking sensor 3 to rotate, realizing real-time adjustment of the pitch angle of the laser weld seam tracking sensor 3. The worm wheel 403 and the worm gear 402 have a self-locking function, which can precisely lock the angle after adjustment, preventing angle deviation caused by welding vibration, and achieving precise adjustment of the pitch accuracy of the laser weld seam tracking sensor 3.

[0029] The second angle adjustment mechanism 5 is disposed on one side of the laser weld seam tracking sensor 3, and the second angle adjustment mechanism 5 is used at least to adjust the swing angle of the laser weld seam tracking sensor in the horizontal direction; specifically, as shown in... Figure 2 As shown, the second angle adjustment mechanism 5 includes a second servo motor 501, and a turntable 502 is provided at the drive end of the second servo motor 501. The fixed end of the first servo motor 401 is fixedly connected to the turntable 502. The rotation of the first servo motor 401 drives the turntable 502 to rotate, thereby driving the first angle adjustment mechanism 4 and the laser weld seam tracking sensor 3 to swing horizontally. A locking structure is provided on the first servo motor.

[0030] The six-axis welding robot 1, the laser weld seam tracking sensor 3, the first angle adjustment mechanism 4, and the second angle adjustment mechanism 5 are electrically connected to the control mechanism.

[0031] This application utilizes a dual-degree-of-freedom servo adaptive angle adjustment structure to achieve dynamic adaptive adjustment of the attitude of the laser weld seam tracking sensor 3 according to the curvature of the weld seam. This effectively solves the problems of laser stripe loss, imaging distortion, and tracking failure of traditional fixed-angle sensors under conditions of curved surfaces, corners, and weld seams with varying curvature. It significantly improves the tracking accuracy and stability of complex irregular weld seams. At the same time, it reduces the process of manually adjusting the installation angle of the laser weld seam tracking sensor 3, thereby reducing maintenance and debugging costs. This makes the laser weld seam tracking equipment adaptable to flexible welding production of various types and irregularly shaped workpieces, with a wider range of applicable scenarios.

[0032] In some implementation examples, each joint of the six-axis welding robot 1 is equipped with a joint encoder. The joint encoder can collect the actual rotation angles of the joints of the six-axis welding robot 1, and the controller of the six-axis welding robot 1 can calculate the real-time pose and welding travel speed of the welding torch 2. This enables the coordinated control of weld morphology parameters and robot motion parameters, providing an accurate data foundation for multi-dimensional attitude and speed advance compensation of the equipment. It effectively improves the problems of attitude adjustment lag and tracking jitter of the laser weld seam tracking sensor 3 during high-speed or variable curvature welding. Simultaneously, it can predict the relative position of the welding torch 2 and the laser weld seam tracking sensor 3, avoiding interference and collisions, significantly improving weld seam tracking accuracy and the safety and stability of equipment operation.

[0033] In some implementations, a narrow-band filter is provided on the camera in front of the lens. The narrow-band filter is used to filter out welding arc light, spatter light and ambient light to reduce interference from welding light and improve recognition accuracy.

[0034] In some implementation cases, a first angle feedback encoder is provided on the drive shaft of the first servo motor 401. The first angle feedback encoder rotates with the first servo motor 401 and can provide real-time feedback on the actual rotation angle of the first servo motor 401, forming an angle closed-loop correction. This can effectively compensate for the adjustment error of the first angle adjustment mechanism 4 and greatly improve the adjustment accuracy and tracking stability of the laser weld seam tracking sensor 3 in the vertical direction.

[0035] In some implementations, a second angle feedback encoder is installed on the drive shaft of the second servo motor 501, and the second angle feedback encoder rotates with the second servo motor 501. The second angle feedback encoder can provide real-time feedback on the actual rotation angle of the second servo motor 501, forming an angle closed-loop correction, which can effectively compensate for the adjustment error of the second angle adjustment mechanism 5, and significantly improve the adjustment accuracy and tracking stability of the laser weld seam tracking sensor 3 in the horizontal direction.

[0036] In some implementation cases, a protective cover 6 is provided on the outside of the first angle adjustment mechanism 4 and the second angle adjustment mechanism 5. The protective cover 6 is provided on the outside of the first angle adjustment mechanism 4 and the second angle adjustment mechanism 5. The protective cover 6 is used to prevent smoke and welding slag from splashing onto the first angle adjustment mechanism 4 and the second angle adjustment mechanism 5, and also to support the first angle adjustment mechanism.

[0037] In another aspect, the present invention discloses a laser weld seam tracking method, based on a laser weld seam tracking device, the laser weld seam tracking method comprising the following steps: S1. Set the attitude thresholds of the laser weld seam tracking sensor corresponding to different curvatures on the control mechanism; specifically, before the welding operation begins, complete the basic calibration (the equipment performs initial imaging and attitude calibration on the standard undeformed straight groove weld seam, and the manual / system records a set of optimal reference parameters, specifically including: 1) the reference projection angle of the laser weld seam tracking sensor (optimal pitch angle and horizontal swing angle under standard working conditions); 2) the standard laser stripe imaging clarity, imaging distance, and field of view; 3) establish the initial groove curvature-optimal projection angle correspondence reference relationship), and input the standard straight weld seam reference projection angle and imaging parameters; establish a "groove curvature-optimal projection angle" database to determine the sensor attitude thresholds corresponding to different curvatures.

[0038] S2: The laser weld seam tracking sensor scans the weld seam to be welded and obtains the real-time curvature of the weld seam, the bevel tilt angle, the weld seam offset direction and deformation parameters. Specifically, during the welding process, the laser weld seam tracking sensor scans the weld seam to be welded in advance, acquires laser stripe images in real time, and extracts the real-time curvature of the weld seam, the bevel tilt angle, the weld seam offset direction and deformation parameters through image processing algorithms. S3: The control mechanism calculates the pitch angle and horizontal swing angle required by the laser weld seam tracking sensor in real time; specifically, the control mechanism combines real-time bevel curvature data and camera imaging field of view to calculate the optimal pitch angle and horizontal swing angle required by the sensor in real time. S4: The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to adjust the overall posture of the laser weld seam tracking sensor according to the required pitch angle and horizontal swing angle; it can accurately adjust the overall posture of the laser weld seam tracking sensor so that the line laser is projected vertically or at the optimal tilt angle onto the current bevel surface, ensuring that the laser stripe completely and uniformly covers the bevel contour. S5: The first angle feedback encoder and the second angle feedback encoder transmit the actual adjustment angle in real time. The control mechanism calculates the difference between the actual adjustment angle and the theoretical optimal angle. The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to compensate for the adjustment error.

[0039] For continuous changes in weld curvature and switching between curved and circular arcs, the system continuously monitors, calculates, and adjusts in real time to maintain the optimal matching between the laser stripes and the bevel throughout the process. It also works in conjunction with the weld correction algorithm to track the trajectory until the welding process is completed.

[0040] Based on the above, the encoders of each joint of the six-axis welding robot in S1 collect the rotation angle of each joint, and the controller of the six-axis welding robot calculates the real-time joint posture, welding torch end pose, and welding torch walking speed; and constructs a multi-dimensional posture database including bevel curvature, bevel inclination angle, welding torch posture, and welding walking speed; specifically, the specific calculation method of welding torch walking speed is as follows: the joint encoders of the six-axis welding robot collect the rotation angle of each joint in real time, and the robot controller, based on the DH forward kinematics model, continuously calculates the spatial coordinate position of the welding torch end in the base coordinate system according to the real-time joint angles. By performing differential operations on the end spatial position at adjacent sampling times, the displacement of the welding torch end per unit time is calculated, and the welding walking linear speed of the welding torch is obtained in real time.

[0041] In S3, the control mechanism matches the multi-dimensional attitude database to calculate the pitch angle and horizontal swing angle required by the laser weld seam tracking sensor; and performs dynamic advance prediction compensation in combination with the welding torch travel speed. Example 1

[0042] A laser weld seam tracking method, based on a laser weld seam tracking device, includes the following steps: S1. Set the attitude threshold of the laser weld seam tracking sensor corresponding to different curvatures on the control mechanism; S2: The laser weld seam tracking sensor scans the weld seam to be welded and obtains the real-time curvature of the weld seam, the bevel inclination angle, the weld seam offset direction and deformation parameters. S3: The control mechanism calculates in real time the pitch angle and horizontal swing angle required by the laser weld seam tracking sensor; S4: The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to adjust the overall attitude of the laser weld seam tracking sensor according to the required pitch angle and horizontal swing angle. S5: The first angle feedback encoder and the second angle feedback encoder transmit the actual adjustment angle in real time. The control mechanism calculates the difference between the actual adjustment angle and the theoretical optimal angle. The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to compensate for the adjustment error. Example 2

[0043] A laser weld seam tracking method, based on a laser weld seam tracking device, includes the following steps: S1. Construct a multi-dimensional attitude database on the control mechanism, including bevel curvature, bevel inclination angle, welding torch posture, and welding travel speed. S2: The laser weld seam tracking sensor scans the weld seam to be welded and obtains the real-time curvature of the weld seam, the bevel inclination angle, the weld seam offset direction and deformation parameters. S3: The control mechanism matches the multi-dimensional attitude database to calculate the pitch angle and horizontal swing angle required by the laser weld seam tracking sensor; and performs dynamic advance prediction compensation in combination with the welding torch travel speed. S4: The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to adjust the overall attitude of the laser weld seam tracking sensor according to the required pitch angle and horizontal swing angle. S5: The first angle feedback encoder and the second angle feedback encoder transmit the actual adjustment angle in real time. The control mechanism calculates the difference between the actual adjustment angle and the theoretical optimal angle. The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to compensate for the adjustment error.

[0044] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A laser weld seam tracking device, characterized in that: include A six-axis welding robot (1) is provided with a welding torch (2) at its drive end. The six-axis welding robot (1) is at least used to drive the welding torch (2) to move in order to weld the workpiece. Laser weld seam tracking sensor (3) is installed on the welding torch (2). The laser weld seam tracking sensor (3) is used at least to acquire groove contour images, calculate weld seam position deviation, calculate groove curvature and groove cross-sectional tilt angle, and to locate and track weld seams. The first angle adjustment mechanism (4) is disposed on one side of the laser weld seam tracking sensor (3), and the first angle adjustment mechanism (4) is used to adjust the pitch angle of the laser weld seam tracking sensor (3). The second angle adjustment mechanism (5) is disposed on one side of the laser weld seam tracking sensor (3), and the second angle adjustment mechanism (5) is used at least to adjust the swing angle of the laser weld seam tracking sensor in the horizontal direction; The control mechanism includes the six-axis welding robot (1), the laser weld seam tracking sensor (3), the first angle adjustment mechanism (4), and the second angle adjustment mechanism (5), which are electrically connected to the control mechanism.

2. The laser weld seam tracking device according to claim 1, characterized in that: The laser weld seam tracking sensor (3) includes a housing, inside which are arranged an industrial camera, a lens, a line laser emitter and a drive circuit board, and the industrial camera, the line laser emitter and the drive circuit board are electrically connected; the industrial camera is used to receive the laser stripe image of the bevel and to acquire the bevel contour image; the line laser emitter is used to emit a line laser.

3. The laser weld seam tracking device according to claim 2, characterized in that: Each joint of the six-axis welding robot (1) is equipped with a joint encoder. The joint encoder is used to collect the actual rotation angle of the joints of the six-axis welding robot (1). The controller of the six-axis welding robot (1) is used to obtain the pose of the welding torch (2).

4. The laser weld seam tracking device according to claim 2, characterized in that: A narrow-band filter is provided on the camera in front of the lens. The narrow-band filter is used to filter out welding arc light, spatter light and ambient light to reduce interference from welding light.

5. A laser weld seam tracking device according to claim 1, characterized in that: The first angle adjustment mechanism (4) includes a first servo motor (401), a worm gear (402) is fixedly connected to the drive end of the first servo motor (401), a worm wheel (403) is meshed on one side of the worm gear (402), a support seat (404) is provided on one side of the worm wheel (403), the support seat (404) rotates with the worm wheel (403), and the laser weld seam tracking sensor (3) is fixedly mounted on the support seat (404).

6. The laser weld seam tracking device according to claim 1, characterized in that: A first angle feedback encoder is provided on the drive shaft of the first servo motor (401), and the first angle feedback encoder rotates with the first servo motor (401).

7. A laser weld seam tracking device according to claim 5, characterized in that: The second angle adjustment mechanism (5) includes a second servo motor (501), the drive end of the second servo motor (501) is provided with a turntable (502), and the fixed end of the first servo motor (401) is fixedly connected to the turntable (502); And / or, a second angle feedback encoder is provided on the drive shaft of the second servo motor (501), and the second angle feedback encoder rotates with the second servo motor (501).

8. A laser weld seam tracking device according to claim 1, characterized in that: The first angle adjustment mechanism (4) and the second angle adjustment mechanism (5) are provided with a protective cover (6) on their outer sides. The protective cover (6) is used to prevent smoke and welding slag from splashing onto the first angle adjustment mechanism (4) and the second angle adjustment mechanism (5).

9. A laser weld seam tracking method, characterized in that: Based on the laser weld seam tracking device according to any one of claims 1-8, the laser weld seam tracking method includes the following steps: S1. Set the attitude threshold of the laser weld seam tracking sensor corresponding to different curvatures on the control mechanism; S2: The laser weld seam tracking sensor scans the weld seam to be welded and obtains the real-time curvature of the weld seam, the bevel inclination angle, the weld seam offset direction and deformation parameters. S3: The control mechanism calculates in real time the pitch angle and horizontal swing angle required by the laser weld seam tracking sensor; S4: The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to adjust the overall attitude of the laser weld seam tracking sensor according to the required pitch angle and horizontal swing angle. S5: The first angle feedback encoder and the second angle feedback encoder transmit the actual adjustment angle in real time. The control mechanism calculates the difference between the actual adjustment angle and the theoretical optimal angle. The control mechanism drives the first angle adjustment mechanism and the second angle adjustment mechanism to compensate for the adjustment error.

10. A laser weld seam tracking method according to claim 9, characterized in that: In S1, the encoders of each joint of the six-axis welding robot collect the rotation angle of each joint, and the controller of the six-axis welding robot calculates the real-time joint posture, welding torch end pose and welding torch walking speed; and constructs a multi-dimensional posture database including bevel curvature, bevel cutting angle, welding torch posture and welding walking speed. In S3, the control mechanism matches the multi-dimensional attitude database to calculate the pitch angle and horizontal swing angle required by the laser weld seam tracking sensor; and performs dynamic advance prediction compensation in combination with the welding torch travel speed.

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