A laser welding method and system based on three-dimensional visual positioning of sealed pipes

Abstract

Embodiments of the present invention provide a laser welding method and system based on three-dimensional visual positioning of sealed pipe fittings, comprising the following steps: S1: acquiring first and second parameters of multiple sealed pipe fittings, scanning the multiple sealed pipe fittings, and obtaining point cloud data for the multiple sealed pipe fittings; selecting a corresponding first welding trajectory generation method to generate the first welding trajectory adapted for the current sealed pipe fitting; and S4: driving a laser welding gun to perform welding along the first welding trajectory, relating to the field of intelligent welding systems. By selecting a single weld center point (point P0) as a reference three-dimensional positioning point, the weld end points (P1 and P2) are quickly calculated based on the pipe fitting size and type, and an interpolation algorithm is used to generate a smooth welding trajectory. Compared to the existing technology that relies on complex calculations for multiple positioning points, this method significantly reduces the computational complexity of point cloud processing and feature extraction, making it particularly suitable for high-speed production lines.

Description

Technical Field

[0001] The present invention relates to the field of intelligent welding systems, and in particular to a laser welding method and system based on three-dimensional visual positioning of sealed pipes. Background Art

[0002] Laser welding technology and intelligent welding systems work closely together in the manufacture of sealed pipe fittings. Relying on 3D visual positioning technology, they form a highly efficient and accurate existing technology system, which is widely used in aerospace, automotive manufacturing, energy equipment and other fields. Intelligent welding systems use high-precision 3D visual sensors (such as laser scanners or structured light cameras) to obtain 3D point cloud data of pipe fittings, providing precise spatial positioning for laser welding, automatically generating optimized welding trajectories, and ensuring precise movement of the laser beam along complex welds. However, existing technologies still have the following shortcomings in practical applications:

[0003] Complexity of multi-point positioning: Existing methods typically rely on multiple 3D positioning points (such as multiple characteristic points of a weld) to generate welding trajectories. This approach requires complex point cloud processing and feature extraction algorithms, resulting in high computational complexity and lengthy trajectory generation times. This approach is particularly inefficient when processing complex pipes such as square tubes, D-shaped tubes, or circular intersecting tubes, making it difficult to meet the demands of high-speed production lines.

[0004] To address the above issues, there is an urgent need for an efficient and precise laser welding method that can quickly generate an adaptive welding trajectory with a minimum of three-dimensional positioning points, while taking into account the adaptability of different pipe types and the dynamic adjustment capability of the welding process to improve the efficiency and quality of automated welding. Summary of the Invention

[0005] According to an embodiment of the present invention, a laser welding method and system based on three-dimensional visual positioning of a sealing pipe are provided to solve the technical problems existing in the above-mentioned background technology.

[0006] In a first aspect of the present invention, a laser welding method based on three-dimensional visual positioning of a sealing pipe is provided.

[0007] The laser welding method based on three-dimensional visual positioning of sealing pipe fittings includes the following steps: S1: acquiring first parameters and second parameters of multiple sealing pipe fittings, scanning the multiple sealing pipe fittings, and obtaining point cloud data of the multiple sealing pipe fittings; S2: extracting weld feature points of the multiple sealing pipe fittings based on the point cloud data, and generating three-dimensional positioning points based on the weld feature points; S3: selecting a corresponding first welding trajectory generation method based on the three-dimensional positioning points and in combination with the first parameters and the second parameters, and generating the first welding trajectory adapted to the current sealing pipe fitting; S4: driving the laser welding gun to perform the welding operation along the first welding trajectory.

[0008] In a second aspect of the present invention, a laser welding system based on three-dimensional visual positioning of sealed pipes is provided.

[0009] The laser welding system based on three-dimensional visual positioning of sealing pipes includes a cabinet and two sets of welding components; the two sets of welding components are connected to the cabinet, and the welding components include a first drive module, a second drive module, a third drive module, a connecting frame, a drive mechanism, a blue light scanner, a laser welding gun and a robotic arm;

[0010] The cabinet is connected to the first driving module, the driving end of the first driving module is connected to the second driving module, the driving end of the second driving module is connected to the third driving module, the driving end of the third driving module is connected to the connecting frame, the connecting frame is connected to the driving mechanism, the output end of the driving mechanism is connected to the robotic arm, and the moving end of the robotic arm is respectively connected to the laser welding gun and the blue light scanner.

[0011] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0012] 1. This invention provides a laser welding method and system based on 3D visual positioning of sealed pipe fittings. By selecting a single weld center point (P0) as the reference 3D positioning point, the system rapidly calculates the weld's two end points (P1 and P2) based on the pipe size and type. An interpolation algorithm is then used to generate a smooth weld trajectory. Compared to existing technologies that rely on complex calculations involving multiple positioning points, this method significantly reduces the computational complexity of point cloud processing and feature extraction, making it particularly suitable for high-speed production lines.

[0013] It should be understood that the contents described in the summary of the invention are not intended to limit the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and other features, advantages and aspects of the embodiments of the present invention will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. In the accompanying drawings, the same or similar reference numerals represent the same or similar elements, wherein:

[0015] Figure 1 A flow chart of a laser welding method based on three-dimensional visual positioning of a sealing pipe according to an embodiment of the present invention is shown;

[0016] Figure 2 A schematic diagram of the weld position of a laser welding method based on three-dimensional visual positioning of a sealing pipe according to an embodiment of the present invention is shown;

[0017] Figure 3A schematic diagram of the three-dimensional structure of a laser welding system based on three-dimensional visual positioning of a sealing pipe according to an embodiment of the present invention is shown;

[0018] Figure 4 A schematic diagram of the connection structure of the welding components of the laser welding system based on three-dimensional visual positioning of the sealing pipe according to an embodiment of the present invention is shown;

[0019] Figure 5 A schematic diagram of the connection structure of a moving module of a laser welding system based on three-dimensional visual positioning of a sealing pipe according to an embodiment of the present invention is shown;

[0020] Figure 6 A partial enlarged view of a moving module of a laser welding system based on three-dimensional visual positioning of a sealing pipe according to an embodiment of the present invention is shown;

[0021] Figure 7 A schematic diagram of the connection structure of a first fixing mechanism of a laser welding system based on three-dimensional visual positioning of a sealing pipe according to an embodiment of the present invention is shown;

[0022] Figure 8 A schematic diagram showing the connection structure of the linkage mechanism of the laser welding system based on three-dimensional visual positioning of the sealing pipe according to an embodiment of the present invention is shown;

[0023] Figure 9 A schematic diagram of the connection structure of the linkage mechanism and the second fixing mechanism of the laser welding system based on three-dimensional visual positioning of the sealing pipe according to an embodiment of the present invention is shown;

[0024] Figure 10 A schematic diagram of the connection structure of the second fixing mechanism of the laser welding system based on three-dimensional visual positioning of the sealing pipe according to an embodiment of the present invention is shown;

[0025] Figure 11 A schematic diagram of the connection structure of a placement platform of a laser welding system based on three-dimensional visual positioning of a sealed pipe according to an embodiment of the present invention is shown.

[0026] Description of reference numerals:

[0027] 1-cabinet, 2-welding assembly, 201-first drive module, 202-second drive module, 203-third drive module, 204-connecting frame, 205-mechanical arm, 206-laser welding gun, 207-blue light scanner, 208-drive mechanism, 3-moving module, 301-fourth drive module, 302-first motor, 303-outer cylinder, 304-electric push rod, 305-connector, 306-outer frame, 307-second motor, 308-telescopic rod, 4-first fixing mechanism, 401-support arm, 402-first limiter, 403-second limiter, 404-rack, 405-gear, 406-positioning column, 407-slide, 408- Back plate, 5-linkage mechanism, 501-dual-axis motor, 502-spindle, 503-cam, 504-first pulley, 505-second pulley, 506-bracket, 507-belt, 508-connecting shaft, 509-pressure plate, 6-second fixing mechanism, 601-positioning plate, 602-axis body, 603-holding piece, 604-shift block, 605-contact rod, 606-limiting sleeve, 607-limiting rod, 608-limiting bar, 609-trapezoidal block, 610-extension piece, 611-spring, 7-placing platform, 701-fixed platform, 702-first seat body, 703-moving platform, 704-negative pressure assembly, 705-second seat body, 8-auxiliary pipe, 9-main pipe. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] In this document, the term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0030] like Figures 1 to 2 As shown in the figure, this laser welding method based on 3D visual positioning of sealed pipes aims to achieve high-precision weld positioning and automated welding through 3D vision technology. This method uses point cloud data to extract weld features, generate adaptive welding trajectories, and perform precise welding based on pipe parameters. Through the coordinated cooperation of the entire process, an intelligent welding system is constructed and realized with high efficiency. The specific steps are as follows:

[0031] Acquire sealing pipe fitting parameters and point cloud data: Obtain the first and second parameters of multiple sealing pipe fittings. The first parameter represents the dimensional parameters of the sealing pipe fitting, including diameter, wall thickness, and length; the second parameter represents the type of sealing pipe fitting, including square pipe, D-shaped pipe, and circular intersecting line pipe. Use 3D visual scanning equipment (such as a laser triangulation measuring instrument or structured light scanner) to scan multiple sealing pipe fittings and obtain high-resolution 3D point cloud data for each sealing pipe fitting. The point cloud data contains geometric information about the pipe fitting surface and weld area.

[0032] Extract weld features and generate 3D positioning points: Preprocess the point cloud data, including denoising (e.g., removing outliers using statistical filtering), segmenting the point cloud (e.g., separating weld regions using region growing algorithms), and smoothing the surface (e.g., using moving least squares). Extract weld feature points based on the preprocessed point cloud data. This includes identifying weld geometric features such as weld width, depth, and centerline curvature, and extracting key feature points along the weld centerline. Based on the extracted weld feature points, 3D positioning points are generated, serving as a reference for subsequent weld trajectory generation.

[0033] Generate an adaptive welding trajectory: Based on the generated 3D positioning points, combined with the first parameter (size of the sealing fitting) and the second parameter (type of the sealing fitting), select an adaptive welding trajectory generation method. The specific steps are as follows: Through the teaching interface or automatic recognition algorithm, select the weld center point as the reference 3D positioning point, marked as point P0; based on point P0 and the sealing fitting type and size parameters, calculate the weld end points, marked as points P1 and P2, respectively; use an interpolation algorithm (such as cubic spline interpolation or Bezier curve) to generate a smooth first welding trajectory that adapts to the weld geometry of the current sealing fitting. This first welding trajectory is optimized, taking into account the motion constraints of the laser welding gun 206 (such as maximum acceleration, welding speed, and welding gun tilt angle) to ensure trajectory smoothness and welding accuracy.

[0034] Performing laser welding: A clamping assembly secures multiple sealed pipes. The clamping assembly adjusts the position and posture of the pipes in real time based on the three-dimensional positioning points to align the pipes with the first welding trajectory. A laser welding gun 206 is driven to perform the welding operation along the first welding trajectory, and its process parameters are controlled, including laser power (e.g., 1.5-3 kW); welding speed (e.g., 3-10 mm / s); and focal position (offset relative to the weld surface). During the welding process, the welding status is monitored in real time (e.g., using an infrared thermometer to monitor the melt pool temperature or a CCD camera to monitor the melt pool shape). Based on the monitoring results, the clamping assembly posture and laser welding gun 206 parameters are dynamically adjusted to ensure weld quality.

[0035] This method utilizes only 3D point cloud data and a feature extraction algorithm to achieve weld positioning errors of less than 0.1mm, ensuring accuracy while saving computational time and costs throughout the welding process. Welding trajectories are automatically generated based on pipe size and type, adapting to a variety of sealing pipes. Optimized trajectories and dynamic control ensure uniform, defect-free welds.

[0036] In a specific embodiment, a laser scanner (resolution 0.05mm) is used to acquire point cloud data for a straight sealing pipe with a diameter of 60mm and a wall thickness of 3mm. After denoising and segmenting the point cloud, the characteristic points of the weld centerline are extracted to generate points P0, P1, and P2. The first welding trajectory is generated based on cubic spline interpolation, with a trajectory length of 120mm. The clamping assembly adjusts the posture of the pipe, and the laser welding gun 206 welds along the trajectory at a speed of 6mm / s and a power of 2.5kW. During the welding process, the molten pool temperature is controlled at 1400-1500℃. After welding is completed, the weld width is consistent, and there are no cracks or pores on the surface, meeting industrial standards. This method is suitable for the automated welding of various sealing pipes, especially for production scenarios with high precision requirements, and has significant industrial applicability.

[0037] Refer to the accompanying drawings in the specification Figure 2 A1 and A2 represent the two sealing pipes to be welded, S represents the weld between sealing pipes A1 and A2, and P0, P1, and P2 represent three points on weld S. In actual welding, for a sealing pipe with a circular cross-section, the arc of the first weld is 180 degrees, that is, the arc enclosed by P0, P1, and P2. The clamping assembly is then switched to the other direction to weld the other side.

[0038] In this embodiment, a clamping assembly is used to secure and dynamically adjust the plurality of sealing tubes during the welding operation to ensure alignment of the weld seam with the laser welding gun 206 .

[0039] It is worth noting that the clamping assembly can adjust the position and posture of the sealing pipe in three-dimensional space. Before the welding operation begins, the clamping assembly automatically adjusts the position of the clamping jaws according to the generated three-dimensional positioning points, fixes multiple sealing pipes in a predetermined posture, and ensures that the weld area is aligned with the initial trajectory of the laser welding gun 206.

[0040] In this embodiment, in a laser welding method based on 3D visual positioning of sealed pipes, generating a first welding trajectory that is suitable for the current sealed pipe is a key step in achieving welding. This embodiment generates a smooth and suitable welding trajectory based on the 3D positioning points by combining the size and type of the sealed pipe. The specific implementation method is as follows:

[0041] The first parameter is the dimensions of the sealing pipe, including but not limited to diameter, wall thickness, and length (e.g., diameter ranges from 10-100mm, wall thickness ranges from 1-5mm). The second parameter is the type of sealing pipe, including round pipe, D-shaped pipe, square pipe, etc. The type determines the geometric characteristics of the weld (e.g., straight or curved).

[0042] 3D Positioning Point Selection and Marking: Using the teach-in interface or an automatic recognition algorithm, the center of the weld is selected from the extracted weld feature points as the reference 3D positioning point, marked as point P0. Point P0 is located midway along the weld's length, with coordinates determined by point cloud data (e.g., with an accuracy of ±0.05mm). The teach-in interface supports manual input or automatic positioning of point P0 using the vision system. The interface displays the 3D model of the pipe fitting and the weld feature points for easy operator confirmation.

[0043] Weld endpoint calculation: Based on point P0, the first parameter (size), and the second parameter (type) of the sealing fitting, the weld endpoints are calculated, labeled P1 and P2. For straight pipes, the relative coordinates of P1 and P2 are calculated along the weld centerline based on the pipe diameter and weld length, with P0 as the reference. For curved or shaped pipes, the locations of P1 and P2 are determined using a surface fitting algorithm (such as the least squares method) based on the pipe curvature and the geometric characteristics of the point cloud data. Ensure that points P1 and P2 align with the actual weld boundary, with a deviation of less than 0.1mm.

[0044] Generation of the first welding trajectory: An interpolation algorithm is used to generate a smooth first welding trajectory based on points P0, P1, and P2. For straight welds, linear interpolation is used to generate a straight trajectory from P1 to P2. For curved welds, cubic spline interpolation or Bezier curves are used to generate a smooth trajectory based on the curvature constraint of P0. During trajectory generation, the motion constraints of the laser welding gun 206 (such as a maximum speed of 10 mm / s and an inclination range of ±15°) are considered, and the trajectory point spacing is optimized (to 0.2-0.5 mm) to ensure continuity and stability of the welding process. The generated trajectory is stored as a 3D coordinate sequence, adapted to the motion control system of the laser welding gun 206.

[0045] Trajectory Verification and Optimization: After generating the first welding trajectory, the trajectory's compatibility is verified using simulation software or a teaching interface to check whether the trajectory aligns with the weld geometry. If there are any deviations (e.g., if the trajectory deviates from the weld centerline by more than 0.1 mm), the P1 and P2 points are readjusted based on the point cloud data, and the trajectory is iteratively optimized. This optimized trajectory ensures stable movement of the laser welding gun 206 along the weld path, reducing weld defects (e.g., burn-through or lack of fusion).

[0046] This method, based on 3D positioning points and an interpolation algorithm, achieves a precise alignment of the trajectory with the weld geometry, achieving positioning accuracy better than 0.1mm. It automatically adapts to various weld configurations, including straight and curved pipes, based on pipe size and type. The teaching interface supports a combination of manual and automatic positioning, improving the efficiency and reliability of trajectory generation. Smoothing the trajectory and optimizing point positions reduces vibration and deviation during welding, ensuring a uniform weld.

[0047] In a specific embodiment, for a straight sealed pipe with a diameter of 40 mm and a wall thickness of 2 mm, the weld length is 100 mm. The weld center point is selected through the teaching interface and marked as P0 (coordinates [0, 0, 0]). Based on the pipe diameter and weld length, P1 ([-50, 0, 0]) and P2 ([50, 0, 0]) are calculated. Linear interpolation is used to generate the first welding trajectory, with a point spacing of 0.3 mm. After the trajectory is verified by simulation, the laser welding gun 206 welds along the trajectory at a speed of 5 mm / s and a power of 2 kW. After welding, the weld width is 1.5 mm, the surface is smooth, and there are no pores or cracks, meeting industrial standards. This method significantly improves the automation and accuracy of laser welding of sealed pipe fittings through precise positioning point selection and trajectory generation algorithms, making it suitable for a variety of industrial welding scenarios.

[0048] In this embodiment, in a laser welding method based on 3D visual positioning of sealed pipes, generating the first welding trajectory on one side of the sealed pipe is a key step in achieving precise welding. This embodiment uses an interpolation algorithm based on the 3D positioning points and the type of sealed pipe to generate a smooth and adaptive welding trajectory. The specific implementation method is as follows:

[0049] Input points and parameters: Use weld feature points, including: P0: The weld center point, used as the reference for trajectory generation, with coordinates determined by point cloud data (positioning accuracy ±0.05mm). P1 and P2: The weld end points, calculated from P0 and the fitting size and type. The fitting type (e.g., round, D-shaped, or square) determines the weld geometry (e.g., straight or curved), affecting the distribution and number of trajectory points.

[0050] Interpolation algorithm generates additional points: Based on points P0, P1, and P2, an interpolation algorithm is used to calculate additional points on the first weld trajectory. The specific method is as follows: For round tube or D-shaped tube welds, linear interpolation or cubic spline interpolation is used to generate additional points between P1 and P2, with a spacing of 0.2-0.5mm. For square tube welds, linear interpolation is preferred to adapt to the linear characteristics of square tube welds, and the spacing between points is kept consistent.

[0051] The number of other points is determined by the type of sealed pipe: For round and D-shaped pipes, a total of 65 points (including P0, P1, and P2) are established, 62 of which are generated through interpolation. For square pipes, a total of 55 points (including P0, P1, and P2) are established, 52 of which are generated through interpolation. During point generation, the motion constraints of the laser welding gun 206 (such as a maximum speed of 10 mm / s and an angular acceleration of 5° / s) are considered to ensure that the trajectory points are evenly distributed and compatible with the welding equipment.

[0052] Generation of the first welding trajectory: Based on points P0, P1, P2, and other points, a three-dimensional coordinate sequence for the first welding trajectory is generated. The trajectory generation step includes connecting all points in sequence to form a continuous path. The path is smoothed (e.g., using a five-point cubic smoothing algorithm) to eliminate potential sharp corners or jitter. The trajectory is verified for compatibility with the weld geometry, ensuring that the trajectory deviates from the weld centerline by less than 0.1 mm. The generated trajectory is output in a standard format (e.g., G-code or a three-dimensional coordinate array) compatible with the motion control system of the laser welding gun 206.

[0053] Trajectory Optimization and Verification: The adaptability of the initial welding trajectory is verified using simulation software or a teaching interface, checking whether the trajectory points align with the actual weld path. If there are any deviations in the trajectory (e.g., a point deviating from the weld boundary by more than 0.1 mm), the distribution of other points is readjusted based on the point cloud data, and the trajectory is iteratively optimized. This optimized trajectory ensures smooth movement of the laser welding gun 206 along the weld path, reducing vibration or offset during the welding process.

[0054] This method, based on an interpolation algorithm and point cloud data, ensures that trajectory points closely match weld geometry, with deviations less than 0.1mm. The number of points can be adjusted based on the type of sealing pipe (round, D-shaped, or square), accommodating a variety of weld configurations. Cubic spline interpolation and path smoothing algorithms ensure trajectory continuity and enhance welding stability. Simulation verification and iterative optimization mechanisms improve trajectory generation efficiency and reduce debugging time.

[0055] In a specific embodiment, for a circular sealing pipe with a diameter of 50 mm and a wall thickness of 2 mm, the weld length is 80 mm. The input points are P0 ([0,0,0]), P1 ([-40,0,0]), and P2 ([40,0,0]). A linear interpolation algorithm is used to generate the other 62 points, for a total of 65 points, with a point spacing of approximately 0.3 mm. Based on these points, the first welding trajectory is generated. After the trajectory is smoothed three times at five points, simulation verification shows that the deviation from the weld centerline is less than 0.08 mm. The laser welding gun 206 welds along the trajectory at a speed of 6 mm / s and a power of 2 kW. After welding is completed, the weld width is 1.2 mm, the surface is smooth, and there is no porosity or unfused surface. This method significantly improves the accuracy and efficiency of laser welding on one side of the sealing pipe through precise point generation and trajectory optimization, and is suitable for a variety of industrial welding scenarios.

[0056] In this embodiment, in the laser welding method based on 3D visual positioning of sealed pipes, verifying the accuracy of the first welding trajectory is a key step in ensuring welding precision. This embodiment compares the distance between the first welding trajectory point and the weld feature point, calculates the deviation index, and verifies the adaptability of the trajectory to ensure that the laser welding gun 206 performs the welding operation along the correct path. The specific implementation method is as follows:

[0057] Input data preparation: Use a set of weld feature points extracted from the point cloud data of the sealed pipe. These feature points represent key geometric points along the weld centerline or boundary, with a positioning accuracy better than 0.05mm. Obtain the point sequence of the first weld trajectory and generate the trajectory points as a 3D coordinate sequence with a point spacing of 0.2-0.5mm.

[0058] Distance calculation: For each point T on the first welding trajectory i (x i ,y i ,z i ), calculate the nearest feature point F in the weld feature point set j (x j ,y j ,z j )’s Euclidean distance D i , the formula is: ,in It means taking the minimum value of all possible j, and finally D i is the distance from point i to its nearest neighbor. The nearest neighbor search algorithm is used to optimize distance calculation, reduce computational complexity, and ensure real-time verification.

[0059] Deviation index calculation: based on the distance D of all trajectory points i , calculate the deviation index E, the specific methods include: average deviation E avg , calculate the average of all distances: Eavg =(1 / N)*sum(D i )(i ranges from 1 to N), where N is the total number of trajectory points and sum represents the sum. Maximum deviation E max , extract the maximum distance value: E max =max(D i ), where max(D i ) means taking all D i The deviation index considers the average deviation and the maximum deviation to evaluate the adaptability of the trajectory as a whole to the weld characteristics.

[0060] Track accuracy check: compare the deviation index with the preset threshold value, which is determined according to the welding process requirements and pipe type (such as straight pipe threshold 0.1mm, curved pipe threshold 0.15mm). The specific rules are as follows: If E avg <theta avg And E max <theta max (theta avg and theta max are the average distance deviation threshold and the maximum distance deviation threshold allowed by the welding process respectively), then it is confirmed that the first welding trajectory is accurate and the trajectory meets the weld geometry requirements (E avg <theta avg It can prevent local over-welding or leakage welding, E max <theta max Ensure the stability of the overall path. If any deviation indicator exceeds the threshold, the trajectory is deemed inaccurate and requires re-optimization (such as adjusting interpolation points or recalculating P1 and P2). Verification results are output through the control system or teaching interface for operator confirmation or intervention.

[0061] Execute welding operation: If the first welding trajectory passes the verification, drive the laser welding gun 206 to perform welding operation along the trajectory. If the trajectory fails to pass the verification, suspend the welding operation and generate a prompt message to guide the operator or control system to correct the trajectory.

[0062] This method uses point cloud data and nearest neighbor distance calculation to achieve trajectory deviation assessment accuracy better than 0.05mm. The threshold is dynamically adjusted based on the pipe type, accommodating various weld configurations, such as straight and curved pipes. Algorithms such as the KD tree are used to optimize distance calculations, meeting real-time verification requirements. Deviation indicator verification ensures that the trajectory is highly consistent with the weld, reducing welding defects such as offset welding or lack of fusion.

[0063] In a specific embodiment, for a straight sealed pipe with a diameter of 60 mm and a wall thickness of 3 mm, the weld length is 100 mm. The first welding trajectory contains 333 points (point spacing 0.3 mm), and the weld feature point set contains 500 points (accuracy 0.05 mm). The KD tree algorithm is used to calculate the distance from each trajectory point to the nearest feature point to obtain the average deviation E avg =0.06mm, maximum deviation E max =0.09mm. The preset threshold is theta avg =0.1mm, theta max =0.15mm, and the verification results indicate an accurate trajectory. Laser welding gun 206 welded along the trajectory at a speed of 5mm / s and a power of 2.5kW. After completion, the weld seam was 1.3mm wide, with a smooth surface and no cracks or pores. This method significantly improves the reliability and quality of the welding trajectory through precise deviation calculation and verification mechanisms, making it suitable for automated welding of various sealing pipe fittings.

[0064] In this embodiment, in a laser welding method based on three-dimensional visual positioning of sealed pipes, when the deviation index of the first welding trajectory is greater than or equal to a preset threshold, it indicates that the trajectory does not fully match the weld characteristics, and a second welding trajectory needs to be generated as a new welding path to ensure welding accuracy and quality. This embodiment regenerates an adapted second welding trajectory based on point cloud data and weld characteristic points, and drives the laser welding gun 206 to perform the welding operation. The specific implementation method is as follows:

[0065] Deviation index evaluation: The first welding trajectory deviation index calculated using (trajectory calibration) includes: average deviation E avg , the formula is: E avg =(1 / N)*sum(D i )(i ranges from 1 to N), where D i is the Euclidean distance from the trajectory point to the nearest weld feature point, N is the total number of trajectory points, and sum represents the sum. max , the formula is: E max =max(D i ), where max(D i ) represents the maximum distance. Compare the deviation index with the preset threshold (such as straight pipe: theta avg =0.1mm, theta max =0.15mm; elbow: theta avg =0.15mm, theta max =0.2mm): If E avg >=theta avg or E max >=theta max, then the first welding trajectory is inaccurate, triggering the second welding trajectory generation process.

[0066] Reanalyze point cloud data and weld feature points: Based on the generated point cloud data and weld feature point set, reanalyze the weld geometric characteristics, including: extracting the curvature, width and boundary points of the weld centerline with an accuracy better than 0.05mm.

[0067] Identify the area with large deviation of the first welding trajectory (such as the distance D i Exceeding theta max The weld seam is then re-divided using a point cloud segmentation algorithm (such as a region growing-based segmentation method) to ensure that the feature points cover the entire weld seam.

[0068] Generate a second weld trajectory: Based on the reanalyzed weld feature points, adjust the reference points (P0, P1, and P2). If the deviation is primarily due to reference point errors, reselect the weld center point P0 (optimize the position using the weighted average method) and recalculate the two end points P1 and P2. If the deviation is due to trajectory interpolation, adjust the interpolation algorithm parameters (such as increasing the number of control points for cubic spline interpolation or reducing the point spacing to 0.1-0.3 mm).

[0069] An interpolation algorithm is used to generate the second welding trajectory. For straight pipe welds, linear interpolation is used to generate a new point sequence. For curved or shaped pipe welds, cubic spline interpolation or Bezier curves are used to generate a smooth path based on curvature constraints in key areas. The number of points in the second welding trajectory is determined by the pipe type (e.g., 65 points for round and D-shaped pipes; 55 points for square pipes), and the point spacing is optimized to 0.1-0.3mm. The trajectory is smoothed (e.g., using a five-point cubic smoothing algorithm) to ensure smooth movement of the laser welding gun 206 with a deviation of less than 0.1mm.

[0070] Second welding track verification: Repeat the verification process for the second welding track: calculate the distance D from each track point to the nearest weld feature point i Calculate the deviation index E avg and E max . Compare with the preset threshold, if E avg <theta avg And E max <theta max , then the second welding trajectory is confirmed to be accurate. If it still does not meet the threshold, iterative optimization is performed, or the operator is prompted to manually adjust the key points through the teaching interface.

[0071] Execute the welding operation: The verified second welding trajectory is used as the new welding path and output as a three-dimensional coordinate sequence (e.g., in G-code format) for adaptation to the motion control system of laser welding gun 206. Laser welding gun 206 is driven to perform the welding operation along the second welding trajectory. Control parameters include: laser power: 1.5-3kW; welding speed: 3-10mm / s; focal position: offset from the weld surface by ±0.2mm. During the welding process, the weld state is monitored in real time (e.g., using a CCD camera to monitor the molten pool shape), and welding gun parameters are dynamically adjusted to ensure weld quality.

[0072] This method automatically generates an adapted secondary welding trajectory based on point cloud data and deviation analysis, significantly improving trajectory accuracy. Weld feature points are reanalyzed with positioning errors less than 0.05mm, ensuring high consistency between the trajectory and weld geometry. It supports a variety of pipe types, including round, D-shaped, and square tubes, with adaptive adjustment of the number of points and interpolation algorithm. Through secondary verification and real-time monitoring, weld defects (such as offset welding or burn-through) are reduced, improving weld consistency.

[0073] In a specific embodiment, for a circular sealing pipe with a diameter of 50 mm and a wall thickness of 2 mm, the weld length is 80 mm. The verification result of the first welding track (65 points, point spacing 0.3 mm) is E avg =0.12mm, E max =0.18mm, exceeding the preset threshold (theta avg =0.1mm, theta max =0.15mm). The system re-analyzes the weld feature points based on the point cloud data, identifies the deviation concentration area, adjusts the P0 point and optimizes the interpolation parameters to generate the second welding trajectory (65 points, point spacing 0.2mm). The second trajectory verification result is E avg =0.05mm, E max =0.08mm, which meets the threshold requirement. The laser welding gun 206 welds along the second track at a speed of 6mm / s and a power of 2kW. After welding, the weld width is 1.2mm, the surface is flat, and there are no pores or cracks.

[0074] This method utilizes a deviation-triggered second trajectory generation and verification mechanism to improve welding efficiency while also incorporating a self-correction mode to correct weld position. This allows operators to easily identify weld deviations caused by factors such as sealing pipes. This significantly improves the reliability and quality of the welding path and is suitable for automated welding of various sealing pipes. The entire welding path calculation process, from simple to complex, ensures weld accuracy while maintaining efficiency.

[0075] In addition, by Figures 3 to 11As shown, another embodiment of the present invention provides a laser welding system based on three-dimensional visual positioning of sealed pipes. The intelligent welding system comprises a cabinet 1 and two sets of welding assemblies 2. The cabinet 1 serves as the basic support structure for the entire system, carrying and securing the two sets of welding assemblies 2. The two sets of welding assemblies 2 are responsible for welding different weld seam locations on multiple sealed pipes. A first drive module 201 is fixedly mounted on the cabinet 1. The first drive module 201 utilizes a linear motion mechanism driven by a servo motor, with its drive end capable of linear motion along a first direction (e.g., the X-axis). The drive end of the first drive module 201 is connected to the base of the second drive module 202 via a rigid flange, ensuring smooth and precise motion transmission. The second drive module 202: The base of the second drive module 202 is fixedly connected to the drive end of the first drive module 201. The second drive module 202 also utilizes a linear motion mechanism driven by a servo motor, with its drive end capable of linear motion along a second direction (e.g., the Y-axis, perpendicular to the first direction). The driving end of the second drive module 202 is fixedly connected to the base of the third drive module 203 via a connector. Third drive module 203: The base of the third drive module 203 is connected to the driving end of the second drive module 202. The driving end of the third drive module 203 is capable of linear motion along a third direction (e.g., the Z-axis, perpendicular to the first and second directions), thereby enabling position adjustment within three dimensions. The driving end of the third drive module 203 is connected to subsequent components via a connecting frame 204. Connecting frame 204: The function of connecting frame 204 is to transmit the motion of the three-axis drive module to the drive mechanism 208, while also providing a stable support platform for the installation of the robotic arm 205 and its accessories. Drive mechanism 208: The drive mechanism 208 is fixed to the connecting frame 204. Its input end synchronizes with the movement of the connecting frame 204, and its output end is connected to the base of the robotic arm 205. The drive mechanism 208 includes a multi-degree-of-freedom rotational drive unit (such as a servo motor or stepper motor combination) to achieve posture adjustment of the robotic arm 205. The driving mechanism 208 is connected to the robotic arm 205 through a high-precision reducer to ensure the smoothness of movement and positioning accuracy. Robotic arm 205: The robotic arm 205 is a multi-joint mechanical structure, and its base is connected to the output end of the driving mechanism 208, which can realize multi-axis rotation and spatial positioning under the control of the driving mechanism 208. The mobile end of the robotic arm 205 is designed with a universal mounting interface for fixing the laser welding gun 206 and the blue light scanner 207 respectively. The range of motion and flexibility of the robotic arm 205 can meet the welding requirements of complex curved pipe fittings. Laser welding gun 206 and blue light scanner 207: The laser welding gun 206 and the blue light scanner 207 are respectively fixed to the mobile end of the robotic arm 205. The laser welding gun 206 is used to output a laser beam to perform the welding task of sealed pipe fittings; the blue light scanner 207 is used to perform three-dimensional scanning of the surface of the pipe fitting to obtain high-precision spatial position data.

[0076] In actual use, the first drive module 201, the second drive module 202, and the third drive module 203 work together, precisely controlled by servo motors, to move the connecting frame 204 to the initial scanning area of the pipe. Driven by the robotic arm 205, the blue light scanner 207 performs high-precision three-dimensional scanning of the pipe surface. By emitting blue light and receiving reflected light, the blue light scanner 207 generates point cloud data of the pipe surface. This point cloud data is processed by the control system to form a three-dimensional spatial model of the pipe, which is used for subsequent welding path planning. Under the control of the drive mechanism 208, the robotic arm 205 can flexibly adjust the scanning angle and distance of the blue light scanner 207 to accommodate pipes of different shapes and sizes. Laser welding execution: After path planning is completed, the first drive module 201, the second drive module 202, and the third drive module 203 work together to drive the connecting frame 204, moving the robotic arm 205 to the welding starting point. The drive mechanism 208 further adjusts the posture of the robotic arm 205 so that the laser output end of the laser welding gun 206 is aligned with the weld seam. The laser welding gun 206 emits a laser beam along a predetermined path to weld the pipe. During the welding process, the robotic arm 205 can adjust the angle and position of the laser welding gun 206 in real time to accommodate the curved surface features of the pipe. Using the high-precision three-dimensional point cloud data generated by the blue light scanner 207, the blue light scanner 207 can accurately identify the spatial position and geometric features of the sealed pipe. Compared to traditional two-dimensional visual positioning, three-dimensional visual positioning can adapt to complex curved surfaces and irregular shapes of pipes, significantly improving positioning accuracy.

[0077] In this embodiment, the clamping assembly consists of a moving module 3, two first fixing mechanisms 4, a linkage mechanism 5, multiple second fixing mechanisms 6, and a placement platform 7. It is used to fix two main pipes 9 and multiple secondary pipes 8. Here, the two main pipes 9 and multiple secondary pipes 8 form a heating pipe. The two main pipes 9 are arranged horizontally on the upper and lower sides, while the multiple secondary pipes 8 are arranged vertically and equidistantly between the two main pipes 9. This ensures the positional stability and accuracy of the pipes during welding.

[0078] In actual use, before welding begins, two main pipes 9 and multiple auxiliary pipes 8 are placed on the placement platform 7 using an external robot or manually. The placement of the main pipes 9 and auxiliary pipes 8 is pre-planned according to the welding process requirements, ensuring that the weld area is exposed within the working range of the laser welding gun 206. The fully automated clamping process and the intelligent detection function of the control system reduce the technical requirements of the operator, simplify the operation process, and improve the usability and reliability of the production line.

[0079] In this embodiment, the movable module 3 specifically includes a fourth drive module 301, which serves as the basic motion unit of the movable module 3 and is securely connected to the upper surface of the cabinet 1. The fourth drive module 301 utilizes a linear guide system or ball screw mechanism driven by a servo motor. Its movable end is capable of high-precision linear motion along a first direction (e.g., the X-axis). The movable end of the fourth drive module 301 is fixedly connected to the base of the first motor 302 via a rigid flange, ensuring stable and accurate motion transmission. The first motor 302 is connected to the movable end of the fourth drive module 301 via bolts or locating pins. The output end of the first motor 302 is connected to the input end of the outer cylinder 303 via a coupling, driving the outer cylinder 303 to rotate about its axis. The first motor 302 is equipped with a high-resolution encoder, enabling precise rotation angle control. The outer cylinder 303 is connected to the output end of the first motor 302 to ensure smooth rotation. The other end of the outer cylinder 303 is securely connected to the base of the electric linear actuator 304. The outer cylinder 303 transmits the rotational motion of the first motor 302 to subsequent components, while also providing guidance and support for the telescopic rod 308. Electric push rod 304: The base of electric push rod 304 is bolted to the outer cylinder 303. The output end of electric push rod 304 is connected to the base end of telescopic rod 308, driving telescopic rod 308 to extend and retract along the axis of outer cylinder 303. Telescopic rod 308: The base end of telescopic rod 308 is connected to the output end of electric push rod 304. The rod body partially slides within the outer cylinder 303, maintaining low-friction contact with the outer cylinder 303 via guide grooves. The free end of telescopic rod 308 is connected to connector 305 to transmit the telescopic motion. Connector 305: One end of connector 305 is connected to telescopic rod 308, and the other end is fixedly connected to outer frame 306 via bolts. Outer frame 306: Outer frame 306 is fixedly connected to connector 305. The outer frame 306 is connected to the two first fixing mechanisms 4 and multiple second fixing mechanisms 6 in the clamping assembly. Second motor 307: Second motor 307 is a servo motor or stepper motor, fixedly mounted near the free end of telescopic rod 308. Its base is bolted to telescopic rod 308. The output end of second motor 307 is connected to the hinge point of connector 305 via a reducer or direct drive mechanism, driving connector 305 to rotate about the hinge point, thereby adjusting the posture of outer frame 306.

[0080] In actual use, before the clamping assembly is activated, the control system calculates the target position of the fixing mechanism based on the placement of the main tube 9 and auxiliary tube 8. The fourth drive module 301 is activated, and through precise control of the servo motor, it drives the first motor 302 along the first direction (X-axis) to its initial position, providing the basis for subsequent movement. The first motor 302 is activated, rotating the outer cylinder 303 about its axis, thereby adjusting the azimuth angle of the telescopic rod 308 and the connecting member 305. The rotation of the outer cylinder 303 changes the orientation of the outer frame 306, aligning the fixing mechanism with the clamping area of the pipe. The electric push rod 304, in response to control commands, drives the telescopic rod 308 to extend or retract along the axis of the outer cylinder 303, thereby adjusting the longitudinal position (e.g., Z-axis) of the connecting member 305 and the outer frame 306. The second motor 307 is activated, and its output terminal drives the connecting member 305 to rotate about its hinge point with the telescopic rod 308, thereby adjusting the tilt angle (e.g., pitch angle about the Y-axis) of the outer frame 306. This rotational movement enables the fixing mechanism to adapt to the complex geometry of the pipe, ensuring an optimal fit between the clamping point and the pipe surface.

[0081] In this embodiment, the first fixing mechanism 4 includes: a back plate 408 fixed on the outer frame 306 of the movable module 3, and connected to the outer frame 306 by high-strength bolts. Two slide grooves 407 are provided on the back plate 408, and the slide grooves 407 are linear grooves. Support arm 401: The two support arms 401 are fixedly connected to the two first limit members 402 by bolts respectively. The function of the support arm 401 is to transmit the clamping force of the first limit member 402 to the main pipe 9, and at the same time, it is connected to the slide groove 407 of the back plate 408 through the positioning column 406 to ensure the guiding nature of the clamping movement. First limit member 402: The two first limit members 402 are clamping components, and are designed with a V-shaped or arc-shaped clamping surface to adapt to the outer diameter of the main pipe 9. The first limit member 402 is slidably connected to the back plate 408 through a sliding connection mechanism, and can move relative to the back plate 408 along the direction of the slide groove 407. Second stoppers 403: Two second stoppers 403 are fixed to either side of the outer frame 306, connected to the outer frame 306 via bolts and fixed relative to the backplate 408. The clamping surface of the second stoppers 403, which also features a V-shaped or arc-shaped design, forms a space for clamping the main pipe 9 together with the first stopper 402. The fixed design of the second stoppers 403 ensures a stable reference position during the clamping process. Positioning posts 406: Two positioning posts 406 are fixedly connected to the two support arms 401 via threads. The positioning posts 406 engage within the grooves 407 of the backplate 408, forming a low-friction sliding connection with the grooves. The positioning posts 406 guide the precise movement of the support arms 401 and the first stopper 402 along the grooves 407, while also transmitting the clamping force through their connection to the rack 404. Rack 404: The two racks 404 are fixedly connected to the two positioning posts 406 via bolts. The rack 404 is arranged along the direction of the slide 407, and its inner teeth mesh with the gear 405. Gear 405: The teeth of the gear 405 mesh with the inner teeth of the two racks 404, and can drive the two racks 404 to move synchronously in opposite directions by rotation.

[0082] In actual use, before clamping the main pipe 9, the two first limiting members 402 are in an initial position away from the second limiting member 403, the two support arms 401 are located at both ends of the slide 407 via the positioning column 406, and the rack 404 is engaged with the gear 405 but is not driven. The main pipe 9 is placed on the placement platform 7, with its axis aligned with the clamping surface of the second limiting member 403. The rotation of the gear 405 drives the two racks 404 to move synchronously inward along the direction of the slide 407. Because the rack 404 is fixedly connected to the positioning column 406, the positioning column 406 slides in the slide 407, guiding the support arms 401 and the first limiting member 402 to approach the second limiting member 403. As the first limiting member 402 approaches the second limiting member 403, the clamping surface of the first limiting member 402 gradually contacts the outer surface of the main pipe 9. The clamping surfaces of the two first stoppers 402 and the two second stoppers 403 work together to securely clamp the main pipe 9 in the desired position. During the clamping process, the V-shaped or curved clamping surfaces ensure that the axis of the main pipe 9 is precisely aligned with the welding path. The synchronized clamping action driven by gear 405 reduces clamping time and improves the overall efficiency of the clamping assembly.

[0083] In this embodiment, the second fixing mechanism 6 is used to fix the auxiliary pipe 8. The structure and connection relationship of each component are described in detail below: the inner surface of the positioning plate 601 is designed to be an arc or V-shaped structure that fits the outer shape of the auxiliary pipe 8 to ensure the initial positioning of the auxiliary pipe 8. The positioning plate 601 is fixed on the outer frame 306 of the movable module 3 and serves as the basic support structure of the second fixing mechanism 6. A bearing hole is provided on the positioning plate 601 for forming a rotational connection with the shaft body 602. Shaft body 602: The shaft body 602 is installed in the bearing hole of the positioning plate 601, and the shaft body 602 is rotationally connected to the positioning plate 601 through a ball bearing to ensure smooth rotation and low friction. One end of the shaft body 602 is fixedly connected to the clamping member 603 by a thread or a keyway, and the other end is connected to the shift block 604 by a keyway or a bolt for transmitting the rotational driving force. A torsion spring is mounted on shaft 602, one end of which is connected to shaft 602 and the other to positioning plate 601. The spring's elastic force drives clamping member 603 to rotate away from the center of positioning plate 601. This prevents clamping member 603 from approaching the center of positioning plate 601, which could affect clamping. Clamping member 603: This is an arc-shaped clamping component with an inner clamping surface that matches the outer diameter of secondary tube 8. High-friction material or a non-slip coating is used to enhance clamping force. Clamping member 603 is secured to shaft 602 by bolts or welding. As shaft 602 rotates, it can approach and tighten against secondary tube 8, achieving a clamping function. Shifter block 604: This is secured to the end of shaft 602 and connected to shaft 602 via a keyway or bolts. The side of shifter block 604 features a protrusion or beveled surface for contact with the end of contact rod 605. The function of the shift block 604 is to convert the movement of the contact rod 605 into the rotational movement of the shaft 602, and then drive the clamping member 603 to clamp the auxiliary pipe 8. Contact rod 605: One end of the contact rod 605 contacts the protrusion or inclined surface of the shift block 604 through a sliding connection, and the other end fits with the trapezoidal block 609. The contact rod 605 can slide in the limit sleeve 606. Limit sleeve 606: The limit sleeve 606 is fixed on the positioning plate 601 and connected to the positioning plate 601. The inner hole of the limit sleeve 606 slides with the contact rod 605. The function of the limit sleeve 606 is to provide a precise linear guide for the contact rod 605 to ensure that its movement trajectory is stable. Limit bar 608: The limit bar 608 is fixed on the outer frame 306 and is connected to the outer frame 306 by bolts. A sliding groove is provided on the limit bar 608 for forming a sliding connection with the trapezoidal block 609. Trapezoidal block 609: Trapezoidal block 609 is slidably connected to stop bar 608. Trapezoidal block 609 fits snugly against contact rod 605, and its top is slidably connected to stop bar 607 via a sliding hole. As trapezoidal block 609 moves, its sloped sides drive contact rod 605.Limiting rod 607: Limiting rod 607 is fixed to limiting bar 608. One end of limiting rod 607 is connected to limiting bar 608 by threading or welding, and the other end passes through the sliding hole of trapezoidal block 609. The function of limiting rod 607 is to provide guidance for the sliding movement of trapezoidal block 609, preventing it from deviating from the predetermined trajectory. Spring 611: Spring 611 is mounted on limiting rod 607, with one end of spring 611 resting on the top of trapezoidal block 609 and the other end resting on the inside of limiting bar 608. Spring 611 provides a reset force during the clamping process, ensuring that trapezoidal block 609 can be smoothly reset when the clamping force is released.

[0084] In actual use, before clamping the auxiliary tube 8, the auxiliary tube 8 is placed on the inner arc or V-shaped surface of the positioning plate 601, and the clamping member 603 is in the initial position away from the auxiliary tube 8. The contact rod 605 is located in the limiting sleeve 606 at a position away from the shift block 604, the trapezoidal block 609 is at the initial end in the sliding groove of the limiting bar 608, and the spring 611 is in a natural or slightly compressed state. When the clamping action is started, the outer frame 306 is driven by the moving module 3 to move in a predetermined direction, driving the limiting bar 608 and the trapezoidal block 609 to move closer to the positioning plate 601. The trapezoidal block 609 slides in the sliding groove of the limiting bar 608, while maintaining stable movement through the guidance of the limiting rod 607. The movement of the trapezoidal block 609 pushes the contact rod 605 to slide forward in the limiting sleeve 606. Clamping action: The front end of the contact rod 605 contacts the protrusion or inclined surface of the shift block 604, applying a thrust to rotate the shift block 604 around the axis of the shaft body 602. The rotation of the shift block 604 drives the shaft body 602 and the clamping member 603 to rotate synchronously. The arc-shaped clamping surface of the clamping member 603 gradually approaches the auxiliary tube 8 and presses against its outer surface. The clamping member 603 works together with the inner surface of the positioning plate 601 to firmly clamp the auxiliary tube 8 in the predetermined position. The guiding effect of the limit rod 607 and the limit sleeve 606 prevents the trapezoidal block 609 and the contact rod 605 from shifting during the clamping process.

[0085] In this embodiment, the linkage mechanism 5 is used to coordinate the clamping action of the first fixing mechanism 4 and the second fixing mechanism 6. The structure and connection relationship of each component are described in detail below: The dual-axis motor 501 is a high-precision servo motor, which is fixedly mounted on the connector 305 of the mobile module 3. The dual-axis motor 501 has a bidirectional output shaft, which can realize unidirectional or unidirectional driving. Main shaft 502: The main shaft 502 is fixedly connected to the output shaft on one side of the dual-axis motor 501. The other end of the main shaft 502 is rotatably connected to the bracket 506 through a bearing, and the middle part of the main shaft 502 is fixedly connected to the cam 503 and the first pulley 504. Cam 503: The cam 503 is fixed on the main shaft 502 and is connected to the main shaft 502 by a keyway or bolt. The contour design of the cam 503 is non-circular, including a raised part and a low-position part, and its surface is in contact with the top surface of the pressure plate 509. The raised portion of cam 503 pushes pressure plate 509 downward, triggering the clamping action of second fixing mechanism 6. It's worth noting that when the raised portion of cam 503 contacts pressure plate 509, the sealing tube is clamped. Pressure plate 509: The top surface of pressure plate 509 slides in contact with the contoured surface of cam 503, while the bottom surface is fixedly connected to extension member 610 of second fixing mechanism 6 via bolts or welding. This ensures smooth movement. The function of pressure plate 509 is to convert the rotational motion of cam 503 into linear motion of extension member 610. First pulley 504: The first pulley 504 is fixed to the main shaft 502 and connected to the main shaft 502 via a keyway or bolts. The outer periphery of the first pulley 504 is provided with a toothed or grooved structure that meshes with belt 507, transmitting the rotational motion of the main shaft 502 to the second pulley 505. The first pulley 504 is mounted on a bracket 506. Second pulley 505: The second pulley 505 is fixed to the connecting shaft 508 and connected to the connecting shaft 508 via a keyway or bolts. The outer periphery of the second pulley 505 engages with the belt 507, and the second pulley 505 is mounted on the bracket 506 via a bearing. Connecting shaft 508: One end of the connecting shaft 508 is fixedly connected to the second pulley 505, and the other end is connected to the gear 405 of the first fixing mechanism 4 via a coupling or gear. The connecting shaft 508 is rotatably connected to the bracket 506 via a bearing, and is used to transmit the rotational motion of the second pulley 505 to the first fixing mechanism 4. Bracket 506: Bracket 506 is used to support the rotational motion of the main shaft 502, the first pulley 504, the second pulley 505, and the connecting shaft 508.

[0086] In actual use, before the clamping action begins, the dual-axis motor 501 is in standby mode, and the main shaft 502 and connecting shaft 508 are stationary. The lower portion of the cam 503 engages the pressure plate 509, which is in the upper position, and the clamping action of the second fixing mechanism 6 is not triggered. The first pulley 504 and the second pulley 505 are connected by a belt 507 but are not rotating. The gear 405 of the first fixing mechanism 4 is in its initial position. When the clamping command is issued, the dual-axis motor 501 is activated, and its output shaft drives the main shaft 502 to rotate. The rotation of the main shaft 502 simultaneously drives the cam 503 and the first pulley 504 to rotate synchronously. As the main shaft 502 rotates, the raised portion of the cam 503 gradually contacts the top surface of the pressure plate 509, pushing the pressure plate 509 to move. The movement of the pressure plate 509 drives the trapezoidal block 609 and contact rod 605 of the second fixing mechanism 6 through the extension member 610, thereby triggering the clamping member 603 to rotate and clamp the auxiliary pipe 8. The contour design of the cam 503 ensures that the triggering timing of the clamping action is synchronized with the clamping action of the first fixing mechanism 4. The rotation of the main shaft 502 drives the second pulley 505 to rotate through the first pulley 504 and the belt 507. The second pulley 505 drives the connecting shaft 508 to rotate, and the rotational motion of the connecting shaft 508 is transmitted to the gear 405 of the first fixing mechanism 4 through the transmission mechanism. The gear 405 drives the rack 404 to move, so that the first limit member 402 approaches the second limit member 403, clamping the main pipe 9. After clamping is completed, the dual-axis motor 501 remains locked through the closed-loop control system, and the raised part of the cam 503 continuously presses the pressure plate 509 to maintain the clamping force of the second fixing mechanism 6; the rotational force of the connecting shaft 508 maintains the clamping state of the first fixing mechanism 4 through the gear 405 and the rack 404. The rigid design of the bracket 506 ensures that there is no obvious vibration during the transmission process. When welding is complete, the dual-axis motor 501 rotates in the reverse direction, causing the lower portion of the cam 503 to contact the pressure plate 509. This plate 509, under the restoring force of the spring 611 of the second fixing mechanism 6, moves upward, releasing the clamping force on the secondary pipe 8. Simultaneously, the connecting shaft 508 rotates in the reverse direction, driving the gear 405 and rack 404 to move in the reverse direction, causing the first stopper 402 to release the primary pipe 9. The dual-axis motor 501 and the cam-pulley transmission system ensure that the clamping actions of the first fixing mechanism 4 and the second fixing mechanism 6 are carried out synchronously, thereby improving the clamping coordination of the main pipe 9 and the auxiliary pipe 8. It is worth noting that the cam 503 only rotates half a circle during the entire fixing process. The entire process is demonstrated as follows: when the first fixing mechanism 4 and the second fixing mechanism 6 are in a fixed position, the cam 503 rotates half a circle. At this time, the raised part of the cam 503 contacts the pressure plate 509 and drives the pressure plate 509 to move downward to complete the clamping of the auxiliary pipe 8. At the same time, the first limit member 402 and the second limit member 403 clamp and fix the main pipe 9, and the clamping force is maintained by relying on the mechanical limit of the dual-axis motor 501.

[0087] In this embodiment, the placement platform 7 includes: a fixed platform 701 fixedly mounted on the upper surface of the cabinet 1. A first base 702: Multiple first bases 702 are fixed to the surface of the fixed platform 701 and are used to initially position the auxiliary pipe 8. A movable platform 703: Two movable platforms 703 are respectively mounted on the front and rear sides of the fixed platform 701 and are slidably connected to the guide rails of the fixed platform 701 via sliding guides or ball bearings. The movable platforms 703 can move a limited distance in the front-to-back direction on the fixed platform 701. A second base 705: Multiple second bases 705 are fixed to the surfaces of the two movable platforms 703 and connected to the movable platforms 703 via bolts or locating pins. The top surface of the second base 705 is also designed with an arc-shaped or V-shaped groove structure that matches the shape of the main pipe 9 and is used to initially position the main pipe 9. A negative pressure assembly 704: The negative pressure assembly 704 is a vacuum adsorption system installed in the internal cavity of the second base 705 and connected to an external vacuum pump via a sealed pipe. The negative pressure component 704 includes a suction cup or adsorption hole, which is arranged on the arc-shaped or V-grooved surface of the second base body 705 and can absorb the outer surface of the main pipe 9 through negative pressure to ensure its stability after placement.

[0088] In actual use, before placing the main pipe 9 and the auxiliary pipe 8, the distance between the two movable platforms 703 must be adapted to the length of the auxiliary pipe 8. The current position must ensure that the first fixing mechanism 4 and the second fixing mechanism 6 can clamp the two main pipes 9 and multiple auxiliary pipes 8. Furthermore, the external manipulator must ensure that the opening of the main pipe 9 is aligned with the auxiliary pipe 8. This ensures that the auxiliary pipe 8 can be aligned with the opening of the main pipe 9 and the welding can be completed. After placement is completed, the negative pressure assembly 704 is activated, and the external vacuum pump generates negative pressure within the suction cup or adsorption hole of the second base 705 through the pipeline. The negative pressure suction force acts on the outer surface of the main pipe 9, firmly adsorbing it into the positioning groove of the second base 705, preventing the auxiliary pipe 8 from shifting during the positioning process.

[0089] The above specific embodiments do not constitute a limitation on the scope of protection of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors.

Claims

1. A laser welding system based on three-dimensional visual positioning of sealed pipes, characterized in that: The system is applied to a laser welding method based on three-dimensional visual positioning of sealed pipes, which includes the following steps: S1: Acquire first parameters and second parameters of a plurality of sealing pipes, scan the plurality of sealing pipes, and obtain point cloud data of the plurality of sealing pipes; S2: extracting a plurality of weld feature points of the sealing pipe based on the point cloud data, and generating three-dimensional positioning points based on the weld feature points; S3: selecting a corresponding first welding trajectory generation method based on the three-dimensional positioning point and in combination with the first parameter and the second parameter to generate the first welding trajectory adapted to the current sealing pipe fitting; S4: driving the laser welding gun (206) to perform a welding operation along the first welding trajectory; The system comprises a cabinet (1) and two sets of welding assemblies (2); the two sets of welding assemblies (2) are connected to the cabinet (1); the welding assemblies (2) comprise a first drive module (201), a second drive module (202), a third drive module (203), a connecting frame (204), a drive mechanism (208), a blue light scanner (207), a laser welding gun (206), and a robotic arm (205); The cabinet (1) is connected to the first drive module (201), the drive end of the first drive module (201) is connected to the second drive module (202), the drive end of the second drive module (202) is connected to the third drive module (203), the drive end of the third drive module (203) is connected to the connecting frame (204), the connecting frame (204) is connected to the drive mechanism (208), the output end of the drive mechanism (208) is connected to the robotic arm (205), and the moving end of the robotic arm (205) is respectively connected to the laser welding gun (206) and the blue light scanner (207); It also includes two main pipes (9), a plurality of auxiliary pipes (8), a moving module (3), two first fixing mechanisms (4), a linkage mechanism (5), a plurality of second fixing mechanisms (6) and a placement platform (7); The movable module (3) is used to adjust the positions of the two first fixing mechanisms (4) and the plurality of second fixing mechanisms (6); the linkage mechanism (5) is used to synchronously drive the two first fixing mechanisms (4) and the plurality of second fixing mechanisms (6); the two first fixing mechanisms (4) and the second fixing mechanisms (6) are respectively used to fix the two main pipes (9) and the plurality of auxiliary pipes (8); the placement platform (7) is used to place the two main pipes (9) and the plurality of auxiliary pipes (8) and cooperate with the two first fixing mechanisms (4) and the plurality of second fixing mechanisms (6) to clamp the two main pipes (9) and the plurality of auxiliary pipes (8); The first fixing mechanism (4) comprises two supporting arms (401), two first limiting members (402), two second limiting members (403), two racks (404), a gear (405), two positioning columns (406), two sliding grooves (407) and a back plate (408); The two support arms (401) are respectively connected to the two first limiting members (402), the two first limiting members (402) are slidably connected to the back plate (408), the two sliding grooves (407) are opened on the back plate (408), the two positioning columns (406) are respectively slidably connected to the two sliding grooves (407), the two positioning columns (406) are respectively connected to the two support arms (401), the two positioning columns (406) are respectively connected to the two racks (404), the inner sides of the two racks (404) are meshed with the gear (405), and when the first limiting member (402) moves in a direction close to the second limiting member (403), the first limiting member (402) and the second limiting member (403) clamp the main pipe (9).

2. The laser welding system based on three-dimensional visual positioning of sealed pipes according to claim 1 is characterized in that: The mobile module (3) comprises a fourth driving module (301), a first motor (302), an outer cylinder (303), a telescopic rod (308), an electric push rod (304), a connecting piece (305), an outer frame (306) and a second motor (307); The movable end of the fourth driving module (301) is connected to the first motor (302), the output end of the first motor (302) is connected to the outer cylinder (303), the outer cylinder (303) is connected to the electric push rod (304), the output end of the electric push rod (304) is connected to the telescopic rod (308), the telescopic rod (308) is connected to the connecting member (305), the connecting member (305) is connected to the outer frame (306), the second motor (307) is connected to the telescopic rod (308), the output end of the second motor (307) is connected to the connecting member (305), and the second motor (307) can drive the connecting member (305) to rotate at a hinge point between the connecting member (305) and the telescopic rod (308).

3. The laser welding system based on three-dimensional visual positioning of sealed pipes according to claim 2 is characterized in that: The two second limiting members (403) are connected to two sides of the outer frame (306); The second fixing mechanism (6) includes a positioning plate (601), a shaft (602), a clamping member (603), a shifting block (604), a contact rod (605), a limiting sleeve (606), a limiting rod (607), a spring (611), an extension member (610), a trapezoidal block (609) and a limiting bar (608); The inner side of the positioning plate (601) matches the shape of the auxiliary tube (8), the positioning plate (601) is rotatably connected to the shaft (602), the shaft (602) is connected to the clamping member (603), the clamping member (603) can be pressed against the auxiliary tube (8), the shift block (604) is connected to the shaft (602), the contact rod (605) can touch the shift block (604) and drive the clamping member (603) to rotate in the direction close to the auxiliary tube (8), the limiting sleeve (606) is slidably connected to the contact rod (605), and the limiting sleeve ( 606) is connected to the positioning plate (601), the contact rod (605) is fitted with the trapezoidal block (609), the trapezoidal block (609) is slidably connected to the limiting bar (608), the limiting bar (608) is connected to the outer frame (306), the limiting rod (607) is connected to the limiting bar (608), the limiting rod (607) is slidably connected to the trapezoidal block (609), the spring (611) is sleeved on the limiting rod (607), and the two ends of the spring (611) are respectively connected to the trapezoidal block (609) and the limiting bar (608).

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