A thin-wall welding automatic positioning method and system

Abstract

The embodiment of the present invention provides a thin-wall welding automatic positioning method and system, which obtains 3D point cloud information of a workpiece to be welded, and uses the 3D point cloud information to make a 3D point cloud model of the current workpiece to be welded; inputs a 3D Mesh model of a standard workpiece and a corresponding standard coordinate system, and converts the coordinates of the workpiece to be welded in the standard coordinate system based on standard component parameters, and performs conversion and alignment; obtains a detection target point cloud cluster of the current workpiece to be welded by presetting a 3D standard welding position, extracts the position of matching weld points by a welding point extraction algorithm, and uses the Mesh surface information between weld points to obtain the trajectory of the current target weld; locates the thin-wall lap welding position by using the 3D point cloud information, and improves welding efficiency by combining with a robot.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of weld positioning, and in particular to a thin-wall welding automatic positioning method and system. Background Art

[0002] At present, when welding and assembling large quantities of parts, robots cannot identify the exact welding positions of the many parts one by one due to the large number of parts. Therefore, welding and assembling large quantities of parts (such as automobile assembly) are mainly completed manually. When welding is done manually, the human influence factor is large, so the welding quality and welding efficiency are difficult to guarantee, and the welding stability and welding quality consistency cannot be guaranteed. Summary of the invention

[0003] The embodiment of the present invention provides a thin-wall welding automatic positioning method and system, which locates the thin-wall overlap welding position through three-dimensional point cloud information and improves the welding efficiency by combining with a robot.

[0004] In a first aspect, an embodiment of the present invention provides a thin-wall welding automatic positioning method, comprising:

[0005] Step S1, obtaining three-dimensional point cloud information of the workpiece to be welded, and constructing a three-dimensional point cloud model of the workpiece to be welded based on the three-dimensional point cloud information;

[0006] Step S2, aligning the three-dimensional point cloud model of the workpiece to be welded with the three-dimensional Mesh model of the standard workpiece, and converting the coordinates of the three-dimensional point cloud model of the workpiece to be welded into the reference coordinate system of the three-dimensional Mesh model;

[0007] Step S3, based on a number of preset welding points on each weld in the three-dimensional mesh model, and based on mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model, a target weld trajectory in the workpiece to be welded is obtained.

[0008] Preferably, the step S1 specifically includes:

[0009] A three-dimensional scan is performed on the workpiece to be welded based on a preset scanning trajectory to obtain three-dimensional point cloud information of the workpiece to be welded, the three-dimensional point cloud information is filtered, fused and triangulated, small components that do not need to be welded are removed, and a three-dimensional point cloud model of the workpiece to be welded is obtained after smoothing.

[0010] Preferably, the step S2 specifically includes:

[0011] Obtain a three-dimensional mesh model of the standard workpiece, and construct a reference coordinate system of the standard bus based on the three-dimensional mesh model, with the preset welding point starting point as the initial welding point;

[0012] The rotation and translation matrix of the three-dimensional point cloud model and the reference coordinate system is calculated, and the workpiece to be inspected is converted to the reference coordinate system based on the rotation and translation matrix.

[0013] Preferably, in step S2, calculating the rotation and translation matrix of the three-dimensional point cloud model and the reference coordinate system specifically includes:

[0014] Obtain a directed bounding box of the three-dimensional Mesh model, wherein the directed bounding box is a minimum outer bounding cuboid that completely contains the three-dimensional Mesh model;

[0015] If the point cloud of the workpiece to be detected is within the directed bounding box, it is judged as valid point cloud data; otherwise, the current point cloud data is discarded, and a small piece removal operation is performed on the current point cloud data to obtain valid point cloud data within the maximum connected domain;

[0016] Based on the ICP algorithm and the best fit algorithm, the translation transformation matrix of the three-dimensional point cloud model converted into the three-dimensional Mesh model is obtained, and the point cloud data of the workpiece to be welded is transformed into a reference coordinate system based on the translation transformation matrix.

[0017] Preferably, in step S3, based on a number of preset welding points on each weld in the three-dimensional mesh model, based on mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model, specifically includes:

[0018] Obtain the preset position information of each weld, and obtain the position and patch information of all points within the specified radius of each preset welding point;

[0019] Based on the position and patch information of each point, determine the curvature change value of each point, where the curvature change value is the sum of the absolute values ​​of the angles between the normal vectors of the N points closest to the current point and the normal vector of the current point; if the curvature change value is greater than a preset threshold, determine that the corresponding point is a key candidate point for the preset welding point, otherwise, it is not considered as a key candidate point for the preset welding point;

[0020] Constructing a plane equation based on the current preset welding point, and projecting the key candidate point into the plane equation of the constructed plane;

[0021] In the plane equation, small components are removed from key candidate points, and an area whose curvature change is greater than a preset curvature threshold is searched as a key area;

[0022] Performing curve fitting on the points in the key area to obtain a curve equation, and taking the points on the curve equation as candidate welding points;

[0023] At the candidate welding point, the triangular facet information is collected, and the best point is searched within a preset radius. The candidate welding point is updated based on the best point to serve as the position of the target welding point.

[0024] Preferably, in step S3, obtaining the target weld trajectory in the workpiece to be welded specifically includes:

[0025] Based on the position of the target welding point and the three-dimensional surface information of the three-dimensional Mesh model, the trajectory of the target welding point is obtained.

[0026] In a second aspect, an embodiment of the present invention provides a thin-wall welding automatic positioning system, comprising:

[0027] A three-dimensional scanning module is used to obtain three-dimensional point cloud information of the workpiece to be welded, and to construct a three-dimensional point cloud model of the workpiece to be welded based on the three-dimensional point cloud information;

[0028] A coordinate alignment module aligns the three-dimensional point cloud model of the workpiece to be welded with the three-dimensional Mesh model of the standard workpiece, and converts the coordinates of the three-dimensional point cloud model of the workpiece to be welded into the reference coordinate system of the three-dimensional Mesh model;

[0029] The welding trajectory matching module obtains the target weld trajectory in the workpiece to be welded based on a number of preset welding points on each weld in the three-dimensional Mesh model and based on the mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model.

[0030] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the automatic positioning method for thin-wall welding as described in the embodiment of the first aspect of the present invention are implemented.

[0031] In a fourth aspect, an embodiment of the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the automatic positioning method for thin-wall welding as described in the embodiment of the first aspect of the present invention.

[0032] An embodiment of the present invention provides an automatic positioning method and system for thin-wall welding, which obtains three-dimensional point cloud information of a workpiece to be welded, and uses the three-dimensional point cloud information to make a three-dimensional point cloud model of the current workpiece to be welded; inputs a three-dimensional Mesh model of a standard workpiece and a corresponding standard coordinate system, and converts the coordinates of the workpiece to be welded in the standard coordinate system based on standard component parameters, and performs conversion and alignment; obtains a detection target point cloud cluster of the current workpiece to be welded by presetting a three-dimensional standard welding position, extracts the position of matching weld points by a welding point extraction algorithm, and obtains the trajectory of the current target weld by using the Mesh surface information between weld points; locates the thin-wall lap welding position by using the three-dimensional point cloud information, and improves welding efficiency by combining with a robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A flowchart of an automatic positioning method for thin-wall welding according to an embodiment of the present invention;

[0035] Figure 2 An exemplary diagram of a workpiece to be welded according to an embodiment of the present invention;

[0036] Figure 3 is a schematic diagram of key candidate points according to an embodiment of the present invention;

[0037] Figure 4 is a schematic diagram of a key area according to an embodiment of the present invention;

[0038] Figure 5 is a schematic diagram of output points of a weld according to an embodiment of the present invention;

[0039] Figure 6 FIG. 4 is a schematic diagram of a physical structure according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0041] In the embodiments of the present application, the term "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0042] The terms "first" and "second" in the embodiments of the present application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a system, product or device comprising a series of parts or units is not limited to the listed parts or units, but optionally also includes parts or units that are not listed, or optionally also includes other parts or units inherent to these products or devices. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0043] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0044] At present, when welding and assembling large quantities of parts, robots cannot identify the exact welding positions of the many parts one by one due to the large number of parts. Therefore, welding and assembling large quantities of parts (such as automobile assembly) are mainly completed manually. When welding is done manually, the human influence factor is large, so the welding quality and welding efficiency are difficult to guarantee, and the welding stability and welding quality consistency cannot be guaranteed.

[0045] Therefore, the embodiment of the present invention provides a thin-wall welding automatic positioning method and system, which locates the thin-wall lap welding position through three-dimensional point cloud information, and improves the welding efficiency by combining with a robot. The scheme of the present invention will be described below through multiple embodiments.

[0046] Figure 1According to an embodiment of the present invention, a thin-wall welding automatic positioning method is provided, which uses the three-dimensional point cloud information of the workpiece to be welded (welding point); uses the three-dimensional point cloud information to make a three-dimensional point cloud model of the current workpiece to be welded; inputs the three-dimensional Mesh model of the standard workpiece, and converts the coordinates of the workpiece to be welded in the standard coordinate system of the three-dimensional Mesh model based on the standard part parameters, and performs conversion and alignment; obtains the detection target point cloud cluster of the current workpiece to be welded by presetting the position of the three-dimensional standard welding welding point, extracts the position of the matching weld point through the welding point extraction algorithm, and uses the Mesh surface information between the weld points to obtain the trajectory of the current target weld. The embodiment of the present invention uses the three-dimensional point cloud information to locate the thin-wall lap welding position, and combines with the robot to improve the welding efficiency; the method specifically includes:

[0047] Step S1, obtaining three-dimensional point cloud information of the workpiece to be welded, and constructing a three-dimensional point cloud model of the workpiece to be welded based on the three-dimensional point cloud information;

[0048] In this embodiment, a robot-clamped three-dimensional scanner is used to scan the sample to be welded, and a three-dimensional scan is performed on the workpiece to be welded based on a preset scanning trajectory to obtain three-dimensional point cloud information of the workpiece to be welded, and the three-dimensional point cloud information is filtered, fused and triangulated to remove small components that do not need to be welded. After smoothing, a three-dimensional point cloud model of the workpiece to be welded is obtained, and the three-dimensional point cloud model can be a Mesh model.

[0049] Step S2, aligning the three-dimensional point cloud model of the workpiece to be welded with the three-dimensional Mesh model of the standard workpiece, and converting the coordinates of the three-dimensional point cloud model of the workpiece to be welded into the reference coordinate system of the three-dimensional Mesh model;

[0050] In this embodiment, valid data of the sample to be welded is obtained, and the sample to be welded and the standard sample are aligned to unify the coordinate system; the standard sample is obtained, and a reference coordinate system is established with its coordinate system, and the welding point preset by the instrument is used as the initial welding point; the rotation and translation matrix RT required for the point cloud under the coordinate system of the standard model and the sample to be welded is calculated, and the current sample to be welded is converted to the reference coordinate system, which specifically includes:

[0051] Obtain a directed bounding box of the three-dimensional Mesh model, wherein the directed bounding box is a minimum outer bounding cuboid that completely contains the three-dimensional Mesh model;

[0052] If the point cloud of the workpiece to be detected is within the directed bounding box, it is judged as valid point cloud data; otherwise, the current point cloud data is discarded, and a small piece removal operation is performed on the current point cloud data to obtain valid point cloud data within the maximum connected domain;

[0053] Based on the ICP algorithm and the best fit algorithm, the translation transformation matrix of the three-dimensional point cloud model converted into the three-dimensional Mesh model is obtained, and the point cloud data of the workpiece to be welded is transformed into a reference coordinate system based on the translation transformation matrix.

[0054] Step S3, based on a number of preset welding points on each weld in the three-dimensional mesh model, and based on mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model, a target weld trajectory in the workpiece to be welded is obtained.

[0055] In order to improve detection efficiency and accuracy, the welding point extraction and matching algorithm of the embodiment of the present invention pre-sets multiple uniformly distributed welding points on each weld under the three-dimensional Mesh model; the implementation steps are as follows:

[0056] Obtain the preset position information of each weld, and obtain the position and patch information of all points within the specified radius of each preset welding point;

[0057] For the positions and patch information of all the above points, based on the position and patch information of each point, determine the curvature change value of each point, the curvature change value is the sum of the absolute values ​​of the angles between the normal vectors of the nearest N (preset value) points to the current point and the normal vector of the current point; if the curvature change value is greater than the preset threshold, the corresponding point is judged to be a key candidate point of the preset welding point, otherwise it is not used as a key candidate point of the preset welding point, and the approximate position of the welding point of the workpiece to be welded is determined by the preset welding point, displayed on the digital model for preset, and then searched near the preset welding point on the workpiece to be welded, and the welding point position is extracted, such as Figure 2 As shown in;

[0058] Constructing a plane equation based on the current preset welding point, and projecting the key candidate point into the plane equation of the constructed plane;

[0059] In the plane equation, small components are removed from the key candidate points, and the area with obvious significant adjustment (curvature change is greater than the preset curvature threshold) is searched as the key area. By constructing the plane, all the welding points are realized on one plane, and then all the workpieces to be welded are subsequently projected onto the current plane. The nearest valid point can be quickly found on the plane, that is, the best welding point can be quickly searched around the current preset welding point in the workpiece to be welded, such as Figure 3 As shown in;

[0060] Performing curve fitting on the points in the key area to obtain a curve equation, and taking the points on the curve equation as candidate welding points;

[0061] At the candidate welding point, the triangular facet information is collected, and the best point is searched within a preset radius. The candidate welding point is updated based on the best point to be output as the position of the target welding point, such as Figure 4 as shown in .

[0062] Based on the current corresponding welding point, the trajectory of the target welding point is obtained based on the position of the target welding point and the three-dimensional surface information of the three-dimensional Mesh model.

[0063] The embodiment of the present invention further provides a thin-wall welding automatic positioning system, based on the thin-wall welding automatic positioning method in the above embodiments, comprising:

[0064] A three-dimensional scanning module is used to obtain three-dimensional point cloud information of the workpiece to be welded, and to construct a three-dimensional point cloud model of the workpiece to be welded based on the three-dimensional point cloud information;

[0065] A coordinate alignment module aligns the three-dimensional point cloud model of the workpiece to be welded with the three-dimensional Mesh model of the standard workpiece, and converts the coordinates of the three-dimensional point cloud model of the workpiece to be welded into the reference coordinate system of the three-dimensional Mesh model;

[0066] The welding trajectory matching module obtains the target weld trajectory in the workpiece to be welded based on a number of preset welding points on each weld in the three-dimensional Mesh model and based on the mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model.

[0067] Based on the same concept, the embodiment of the present invention also provides a schematic diagram of an entity structure, such as Figure 6 As shown, the server may include: a processor 810, a communications interface 820, a memory 830 and a communication bus 840, wherein the processor 810, the communications interface 820 and the memory 830 communicate with each other through the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute the steps of the thin-wall welding automatic positioning method described in the above embodiments. For example, it includes:

[0068] Step S1, obtaining three-dimensional point cloud information of the workpiece to be welded, and constructing a three-dimensional point cloud model of the workpiece to be welded based on the three-dimensional point cloud information;

[0069] Step S2, aligning the three-dimensional point cloud model of the workpiece to be welded with the three-dimensional Mesh model of the standard workpiece, and converting the coordinates of the three-dimensional point cloud model of the workpiece to be welded into the reference coordinate system of the three-dimensional Mesh model;

[0070] Step S3, based on a number of preset welding points on each weld in the three-dimensional mesh model, and based on mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model, a target weld trajectory in the workpiece to be welded is obtained.

[0071] In addition, the logic instructions in the above-mentioned memory 830 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0072] Based on the same concept, an embodiment of the present invention further provides a non-transitory computer-readable storage medium, which stores a computer program, which includes at least one code segment, and the at least one code segment can be executed by a main control device to control the main control device to implement the steps of the thin-wall welding automatic positioning method described in the above embodiments. For example, it includes:

[0073] Step S1, obtaining three-dimensional point cloud information of the workpiece to be welded, and constructing a three-dimensional point cloud model of the workpiece to be welded based on the three-dimensional point cloud information;

[0074] Step S2, aligning the three-dimensional point cloud model of the workpiece to be welded with the three-dimensional Mesh model of the standard workpiece, and converting the coordinates of the three-dimensional point cloud model of the workpiece to be welded into the reference coordinate system of the three-dimensional Mesh model;

[0075] Step S3, based on a number of preset welding points on each weld in the three-dimensional mesh model, and based on mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model, a target weld trajectory in the workpiece to be welded is obtained.

[0076] Based on the same technical concept, an embodiment of the present application also provides a computer program, which, when executed by a main control device, is used to implement the above method embodiment.

[0077] The program may be stored in whole or in part on a storage medium packaged together with the processor, or may be stored in whole or in part on a memory not packaged together with the processor.

[0078] Based on the same technical concept, the embodiment of the present application further provides a processor, which is used to implement the above method embodiment. The above processor can be a chip.

[0079] In summary, an embodiment of the present invention provides an automatic positioning method and system for thin-wall welding, which obtains three-dimensional point cloud information of a workpiece to be welded, and uses the three-dimensional point cloud information to make a three-dimensional point cloud model of the current workpiece to be welded; inputs a three-dimensional Mesh model of a standard workpiece and a corresponding standard coordinate system, and converts the coordinates of the workpiece to be welded in the standard coordinate system based on standard part parameters, and performs conversion and alignment; obtains a detection target point cloud cluster of the current workpiece to be welded by presetting a three-dimensional standard welding position, extracts the position of matching weld points by a welding point extraction algorithm, and obtains the trajectory of the current target weld by using the Mesh surface information between weld points; locates the thin-wall lap welding position by using the three-dimensional point cloud information, and improves welding efficiency by combining with a robot.

[0080] The various embodiments of the present invention can be combined arbitrarily to achieve different technical effects.

[0081] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in this application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk SolidStateDisk), etc.

[0082] Those skilled in the art can understand that to implement all or part of the processes in the above-mentioned embodiments, the processes can be completed by computer programs to instruct related hardware, and the programs can be stored in computer-readable storage media. When the programs are executed, they can include the processes of the above-mentioned method embodiments. The aforementioned storage media include: ROM or random access memory RAM, magnetic disk or optical disk and other media that can store program codes.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thin-wall welding automatic positioning method, characterized in that: include: Step S1, obtaining three-dimensional point cloud information of the workpiece to be welded, and constructing a three-dimensional point cloud model of the workpiece to be welded based on the three-dimensional point cloud information; Step S2, aligning the three-dimensional point cloud model of the workpiece to be welded with the three-dimensional Mesh model of the standard workpiece, and converting the coordinates of the three-dimensional point cloud model of the workpiece to be welded into the reference coordinate system of the three-dimensional Mesh model; Step S3, based on a number of preset welding points on each weld in the three-dimensional mesh model, and based on mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model, obtaining a target weld trajectory in the workpiece to be welded; Based on a number of preset welding points on each weld in the three-dimensional Mesh model, based on the mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model, specifically including: Obtain the preset position information of each weld, and obtain the position and patch information of all points within the specified radius of each preset welding point; Based on the position and patch information of each point, determine the curvature change value of each point, where the curvature change value is the sum of the absolute values ​​of the angles between the normal vectors of the N points closest to the current point and the normal vector of the current point; if the curvature change value is greater than a preset threshold, determine that the corresponding point is a key candidate point for the preset welding point, otherwise, it is not considered as a key candidate point for the preset welding point; Constructing a plane equation based on the current preset welding point, and projecting the key candidate point into the plane equation of the constructed plane; In the plane equation, small components are removed from key candidate points, and an area whose curvature change is greater than a preset curvature threshold is searched as a key area; Performing curve fitting on the points in the key area to obtain a curve equation, and taking the points on the curve equation as candidate welding points; At the candidate welding point, the triangular patch information is collected to search for the best point within a preset radius, and the candidate welding point is updated based on the best point to serve as the position of the target welding point; Obtain the target weld trajectory in the workpiece to be welded, specifically including: Based on the position of the target welding point and the three-dimensional surface information of the three-dimensional Mesh model, the trajectory of the target welding point is obtained.

2. The thin-wall welding automatic positioning method according to claim 1 is characterized in that: The step S1 specifically includes: A three-dimensional scan is performed on the workpiece to be welded based on a preset scanning trajectory to obtain three-dimensional point cloud information of the workpiece to be welded, the three-dimensional point cloud information is filtered, fused and triangulated, small components that do not need to be welded are removed, and a three-dimensional point cloud model of the workpiece to be welded is obtained after smoothing.

3. The thin-wall welding automatic positioning method according to claim 1, characterized in that: The step S2 specifically includes: Acquire a three-dimensional mesh model of the standard workpiece, and construct a reference coordinate system of the standard workpiece based on the three-dimensional mesh model, with a preset welding point starting point as the initial welding point; The rotation and translation matrix of the three-dimensional point cloud model and the reference coordinate system is calculated, and the workpiece to be inspected is converted to the reference coordinate system based on the rotation and translation matrix.

4. The thin-wall welding automatic positioning method according to claim 3 is characterized in that: In the step S2, calculating the rotation and translation matrix of the three-dimensional point cloud model and the reference coordinate system specifically includes: Obtain a directed bounding box of the three-dimensional Mesh model, wherein the directed bounding box is a minimum outer bounding cuboid that completely contains the three-dimensional Mesh model; If the point cloud of the workpiece to be detected is within the directed bounding box, it is judged as valid point cloud data; otherwise, the current point cloud data is discarded, and a small piece removal operation is performed on the current point cloud data to obtain valid point cloud data within the maximum connected domain; Based on the ICP algorithm and the best fit algorithm, the translation transformation matrix of the three-dimensional point cloud model converted into the three-dimensional Mesh model is obtained, and the point cloud data of the workpiece to be welded is transformed into a reference coordinate system based on the translation transformation matrix.

5. A thin-wall welding automatic positioning system, characterized in that: include: A three-dimensional scanning module is used to obtain three-dimensional point cloud information of the workpiece to be welded, and to construct a three-dimensional point cloud model of the workpiece to be welded based on the three-dimensional point cloud information; A coordinate alignment module aligns the three-dimensional point cloud model of the workpiece to be welded with the three-dimensional Mesh model of the standard workpiece, and converts the coordinates of the three-dimensional point cloud model of the workpiece to be welded into the reference coordinate system of the three-dimensional Mesh model; A welding trajectory matching module, based on a number of preset welding points on each weld in the three-dimensional mesh model, and based on mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model, obtains a target weld trajectory in the workpiece to be welded; Based on a number of preset welding points on each weld in the three-dimensional Mesh model, based on the mesh surface information between the preset welding points and the point cloud in the three-dimensional point cloud model, specifically including: Obtain the preset position information of each weld, and obtain the position and patch information of all points within the specified radius of each preset welding point; Based on the position and patch information of each point, determine the curvature change value of each point, where the curvature change value is the sum of the absolute values ​​of the angles between the normal vectors of the N points closest to the current point and the normal vector of the current point; if the curvature change value is greater than a preset threshold, determine that the corresponding point is a key candidate point for the preset welding point, otherwise, it is not considered as a key candidate point for the preset welding point; Constructing a plane equation based on the current preset point, and projecting the key candidate point into the plane equation of the constructed plane; In the plane equation, small components are removed from key candidate points, and an area whose curvature change is greater than a preset curvature threshold is searched as a key area; Performing curve fitting on the points in the key area to obtain a curve equation, and taking the points on the curve equation as candidate welding points; At the candidate welding point, the triangular patch information is collected to search for the best point within a preset radius, and the candidate welding point is updated based on the best point to serve as the position of the target welding point; Obtain the target weld trajectory in the workpiece to be welded, specifically including: Based on the position of the target welding point and the three-dimensional surface information of the three-dimensional Mesh model, the trajectory of the target welding point is obtained.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the thin-wall welding automatic positioning method as claimed in any one of claims 1 to 4 are implemented.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the thin-wall welding automatic positioning method as claimed in any one of claims 1 to 4 are implemented.

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