A continuous weld multi-layer multi-pass automatic welding method and system for an industrial robot

Abstract

The present application belongs to the technical field of robot welding, and specifically relates to a continuous weld multi-layer multi-pass automatic welding method and system for an industrial robot, which comprises the following steps: acquiring multi-layer multi-pass weld information of a workpiece to be welded; welding a root pass and recording discrete points on a path thereof in real time; establishing a weld coordinate system with the recorded points as an origin based on a welding reference surface normal vector and a welding direction vector, and determining a transformation matrix thereof relative to a robot base coordinate system; automatically calculating a path point set of all cover passes according to the root pass recorded points and a preset cover pass offset; when the weld is a continuous weld, recalculating cover pass offset points at adjacent weld intersection points and eliminating abnormal points; and finally, adding the processed path points to a robot motion queue in sequence to perform welding. The present application realizes automatic generation of cover pass paths, avoids manual repeated teaching, and guarantees the continuity and efficiency of the welding process by optimizing the paths at the continuous weld intersection points.

Description

Technical Field

[0001] This invention belongs to the field of robotic welding technology, specifically a method and system for continuous multi-layer, multi-pass automatic welding of weld seams using industrial robots. Background Technology

[0002] In industrial robot welding technology, for workpieces with wide weld seams, a multi-layer, multi-pass welding process is typically required to meet welding quality requirements and structural strength. In this process, in addition to the initial root weld, multiple cover welds are subsequently stacked layer by layer on top of the root weld.

[0003] Currently, industrial robots generally face the following technical limitations when performing multi-layer, multi-pass welding tasks: for each layer and each covering weld pass, the welding path still requires manual teaching and programming by the operator via a teach pendant, or at least complex offset settings and verification of the reference path (usually the root weld pass path). This mode, which heavily relies on human experience and repetitive operations, not only makes the welding preparation process cumbersome and inefficient, but also, due to the inevitable random errors introduced by manual teaching, directly affects the accuracy and consistency of the welding trajectory, ultimately adversely impacting the welding quality of the workpiece.

[0004] Existing methods can automatically generate welding paths for each covering weld bead by setting the path offset of the initial root weld bead. For example, by setting a fixed offset, multiple layers and passes of welding paths can be automatically generated on a single weld. However, these methods are usually only applicable to independent, simple single welds. When faced with complex continuous welds composed of multiple straight lines, arcs, etc. connected end to end, existing methods cannot intelligently handle the path connection problem of adjacent welds at corners or intersections. If the offset rules of a single weld bead are simply applied to continuous welds, problems such as trajectory discontinuity, interference between the welding torch and the workpiece, or uneven weld filling can easily occur at corners, thereby disrupting the continuity of the welding process and limiting the application efficiency and scope of automated welding systems on complex workpieces.

[0005] Therefore, developing a method that can automatically, continuously, and without interference complete the multi-layer, multi-pass welding path planning for complex continuous welds has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide an automated method and system for multi-layer, multi-pass continuous weld seams using industrial robots. Based on the root weld path and the offset set in the robot's programming, the method automatically calculates the paths of each covering weld bead. Furthermore, for situations involving welding multiple continuous weld seams simultaneously, the method automatically optimizes the offset of the covering weld beads at the intersection of adjacent weld seams. This avoids interference between the welding torch and the workpiece while ensuring the continuity of the multi-layer, multi-pass welding process for workpieces with multiple weld seams. This method effectively solves the problems of existing technologies, such as reliance on manual teaching, cumbersome processes, and low efficiency due to the inability to weld multiple continuous weld seams simultaneously.

[0007] The technical solution adopted by the present invention to achieve the above objectives is: a multi-layer, multi-pass automatic welding method for continuous weld seams of industrial robots, comprising the following steps:

[0008] Step S1: Obtain multi-layer, multi-pass weld information of the workpiece to be welded; the weld information includes: weld type and position data of the start and end points of each weld;

[0009] Step S2: Control the industrial robot to weld the root weld and record the discrete points on the root weld path in real time according to the set recording interval;

[0010] Step S3: Based on the preset welding reference plane normal vector, welding direction vector and the currently recorded root weld point, establish the weld coordinate system and determine the transformation matrix of the weld coordinate system relative to the robot base coordinate system.

[0011] Step S4: Calculate the set of path points corresponding to all covered welds based on the discrete points recorded in the root weld and the preset offset of the covered weld.

[0012] Step S5: When the weld type contains two or more continuous welds, recalculate the offset point of the covering weld at the intersection of adjacent welds, and judge and remove abnormal covering weld points near the intersection.

[0013] Step S6: Add all processed cover weld path point sets to the robot motion queue in sequence, and control the industrial robot to perform cover weld welding.

[0014] In step S1, the weld type includes single weld and continuous weld;

[0015] The single weld seam refers to a weld seam consisting of only one straight line or one circular arc weld seam welded in a single arc initiation;

[0016] The continuous weld refers to the welding of two or more continuous welds completed in one arc initiation, specifically including straight-to-straight welds, straight-to-circular arc welds, and circular arc-to-circular arc welds;

[0017] The pose data is acquired through robot teaching or scanning with a 3D vision sensor.

[0018] Step S2 specifically includes:

[0019] Step S21: Set welding parameters, including weld information, number of welding layers, number of weld passes per layer, offset of each covering weld pass relative to the root weld pass, and interval distance for recording root weld pass path points.

[0020] Step S22: Transmit welding parameters to the robot controller to create a welding job;

[0021] Step S23: Control the robot to weld the root weld and record the discrete points on the root weld path in real time according to the recorded interval.

[0022] Step S3 specifically includes:

[0023] The origin is the current root weld bead recording point, the X-axis is the welding direction vector, and the Z-axis is the welding reference plane normal vector.

[0024] For straight welds, the welding direction vector is a vector pointing from the starting point to the ending point;

[0025] For circular arc welds, the welding direction vector is the tangent direction vector of the circular arc at the recording point.

[0026] Step S4 includes the following steps:

[0027] Step 41: The preset offset S of the covered weld bead is expressed as:

[0028] in These represent the translational offset of the covering weld bead relative to the root weld bead position in the X, Y, and Z axes of the weld coordinate system, respectively. These represent the rotation angles of the welding torch posture around the X, Y, and Z axes of the weld coordinate system, respectively.

[0029] Step 42: Determine the corresponding transformation matrix for:

[0030]

[0031] in, For the reason The rotation matrix formed, Translation vector ;

[0032] Step 43: Calculate the coverage weld points based on the offset.

[0033] Step S43 specifically includes:

[0034] a) Calculate the points corresponding to the offset of the cover weld bead in the Y-axis and Z-axis directions. for:

[0035]

[0036] in, The first point in the set of root weld points in the robot base coordinate system point, The offset transformation matrix The matrix that retains only the translation components in the Y and Z directions has the following translation vector: ;

[0037] b) X-direction offset calculation method:

[0038] Processing X-axis offset :like Then the cover weld bead extends along the welding direction based on the root weld bead at the start and end points; if If so, then shorten it;

[0039] For straight-line continuous welds and In the case of shortening, the shortening process specifically includes:

[0040] Let the first point of the root weld bead location set of the first straight line segment be... The end point of the root weld point set of the second straight segment, which is continuous with the first straight segment, is... , Let be the unit vector in the direction of the first line segment. The unit vector in the direction of the second line segment;

[0041] In the set of points on the first straight line segment, from Traverse backwards, when the traversal point is reached arrive distance When, adjust this point to and with the adjusted This serves as the actual starting point for the covered weld bead;

[0042] In the set of points on the second straight line segment, from Traverse forward, when the traversal point arrive distance When, adjust this point to and with the adjusted This serves as the actual endpoint of the covered weld bead.

[0043] In step S5, the recalculation of the offset point of the covering weld bead at the intersection of adjacent weld seams specifically includes:

[0044] Step S51: Calculate the two weld direction vectors at the intersection point. and The included angle ;

[0045] Step S52: with With the direction of the X-axis, re-establish the weld coordinate system at the intersection point;

[0046] Step S53: Adjust the Y-axis offset of the weld bead covering the intersection point as follows:

[0047] ;

[0048] Step S54: Using the adjusted offset, combined with the current situation, Translation vector Recalculate the coverage weld points at the intersection. for:

[0049]

[0050] in, The root weld point at the intersection. To use the adjusted Y-axis offset The offset transformation matrix.

[0051] In step S5, the judgment and removal of abnormal weld bead coverage points near the intersection specifically includes:

[0052] Set distance threshold From the intersection Traverse the root weld bead point set forward and backward respectively. For each traversed point, calculate its distance to the root weld bead. distance And its corresponding covered weld points to distance If both conditions are met and If the covered weld bead point is found to be abnormal, it will be removed.

[0053] A welding system for an automated multi-layer, multi-pass continuous weld seam welding method using an industrial robot includes:

[0054] The information acquisition module is used to acquire multi-layer, multi-pass weld information of the workpiece to be welded. The weld information includes the weld type and the position data of the start and end points of each weld.

[0055] The root weld welding and recording module is used to control the industrial robot to weld the root weld and record the discrete points on the root weld path in real time according to the set recording interval.

[0056] The coordinate system processing module is used to establish a weld coordinate system based on the preset welding reference plane normal vector and welding direction vector, with the currently recorded root weld point as the origin, and to determine the transformation matrix of the weld coordinate system relative to the robot base coordinate system.

[0057] The path calculation module is used to calculate the set of path points corresponding to all covered welds based on the discrete points recorded in the root weld and the preset offset of the covered weld.

[0058] The intersection optimization module is used to recalculate the offset point of the covered weld bead at the intersection of adjacent welds when the weld type contains two or more continuous welds, and to judge and remove abnormal covered weld bead points near the intersection.

[0059] The motion control module is used to add all the processed cover weld path points to the robot motion queue in sequence, and control the industrial robot to perform cover weld welding.

[0060] The present invention has the following beneficial effects and advantages:

[0061] 1. This invention uses the weld root path as a reference and automatically calculates the covered weld path of multi-layer and multi-pass welding processes by combining preset offsets, thereby reducing the manual repetitive teaching process and improving operation efficiency and welding quality.

[0062] 2. This invention optimizes the offset algorithm of the covered weld bead at the intersection of adjacent weld seams, ensuring the process continuity when performing multi-layer and multi-pass welding on workpieces with multiple weld seams, thereby improving welding efficiency while ensuring the safety of the welding process.

[0063] 3. The core improvement of this invention lies in the specially designed path optimization algorithm at the intersection (or corner) of adjacent welds, specifically designed for continuous welds composed of multiple line segments. By re-establishing the local coordinate system at the intersection and dynamically adjusting the lateral offset of the covered weld bead at the corner, a smooth and continuous transition of the welding trajectory when the direction changes is ensured. Simultaneously, by calculating and eliminating abnormal path points near the intersection, the risk of collision and interference between the welding torch and the workpiece sidewall caused by simple path offsets is intelligently avoided. This enables the robot to complete multi-layer, multi-pass welding of workpieces with complex contours, truly achieving automated and continuous welding.

[0064] 4. The method proposed in this invention is not only applicable to simple straight welds, but its core algorithm based on vector and coordinate transformation can also effectively handle complex continuous welds containing arc segments (such as straight-arc and arc-arc combinations). By uniformly discretizing the arc path and taking the tangent direction at each point as the welding direction, this invention successfully extends the offset and connection logic of straight welds to curved welds, thereby adapting to the weld geometry encountered in most practical welding applications. This significantly enhances the practical value and promotion potential of this automated welding method in diverse industrial scenarios.

[0065] 5. This invention uses the actual path of the completed root weld bead as a benchmark, combined with preset process offset parameters, and automatically calculates the precise path positions of all covering weld beads through an established weld coordinate system and transformation matrix. This completely eliminates the traditional mode of manually teaching or individually programming each covering weld bead, significantly shortening the preparation time before welding and reducing the technical threshold and labor intensity for operators. At the same time, the algorithm-generated paths have high consistency and repeatability, effectively eliminating random errors introduced by human factors, thereby consistently improving the uniformity and reliability of welding quality. Attached Figure Description

[0066] Figure 1 This is a schematic diagram of the multi-layer, multi-pass welding path of straight and continuous straight welds according to an embodiment of the present invention;

[0067] Figure 2 This is a schematic diagram of the overall workflow of an embodiment of the present invention;

[0068] Figure 3 This is a schematic diagram of the multi-layer, multi-pass welding path of a continuous straight and circular arc weld according to an embodiment of the present invention.

[0069] Figure 4 This is a schematic diagram of the multi-layer, multi-pass welding path of a circular arc and a continuous circular arc weld according to an embodiment of the present invention. Detailed Implementation

[0070] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0071] This invention provides an automated multi-layer, multi-pass welding method for continuous weld seams in industrial robots. By recording the path points of the root weld and based on a set offset, it automatically calculates the path points of the multi-layer, multi-pass weld seams covering the continuous weld seam. Specifically, the continuous weld seams involved in this invention include straight-to-straight weld seams, straight-to-circular arc weld seams, circular arc-to-circular arc weld seams, and more complex combinations of straight lines and circular arcs.

[0072] like Figure 2The diagram shown is a schematic representation of the overall workflow of an embodiment of the present invention. The technical solution adopted by the present invention is as follows: A method for automatic multi-layer, multi-pass continuous weld seam welding of an industrial robot, comprising the following steps:

[0073] 1) Obtain multi-layer, multi-pass weld information, including weld type (such as straight weld, circular arc weld, etc.) and position data of weld start and end points;

[0074] 1-1) Weld types can be divided into single welds and continuous welds. A single weld refers to welding only one straight line or one circular arc weld in one arc initiation; a continuous weld refers to welding two or more continuous welds in one arc initiation, specifically including straight-to-straight welds, straight-to-circular arc welds, circular arc-to-circular arc welds, etc.

[0075] 1-2) The pose data of the weld start and end points includes position information and welding torch posture information, which can be obtained through teaching point positioning or by scanning the weld with a 3D vision sensor. If it is a circular arc weld, in addition to the pose of the start and end points, the pose of the midpoint of the arc also needs to be obtained.

[0076] 2) Weld the root weld and record the discrete points along the root weld path in real time;

[0077] 2-1) Set welding parameters, including weld information, number of layers for multi-layer and multi-pass welding, number of weld passes corresponding to each layer, offset of each covering weld pass relative to the root weld pass, and other relevant welding parameters;

[0078] 2-2) Transmit welding parameters to the robot controller to create multi-layer, multi-pass welding operations;

[0079] 2-3) Start welding the root weld and set the point recording interval distance. Record the discrete points on the root weld path that meet the interval requirements in real time during the welding process.

[0080] 3) Based on the normal vector of the welding reference plane, the welding direction vector, and the current root weld bead recording point position, establish a weld coordinate system and determine the transformation matrix of the weld coordinate system relative to the robot base coordinate system.

[0081] 3-1) The normal vector of the welding reference plane can be set in a custom way, for example, by selecting the Z-axis direction of the welding torch coordinate system or the Z-axis direction of the world coordinate system;

[0082] 3-2) The welding direction vector of a straight weld is from the starting point to the ending point, and the welding direction vector of a circular arc weld is taken from the tangent direction of the arc.

[0083] 3-3) Establish a weld coordinate system with the welding reference plane normal vector as the Z-axis, the welding direction vector as the X-axis, and the current root weld path point as the origin.

[0084] 4) Based on the points recorded in the root weld bead and the preset offset, calculate the set of points corresponding to all covered weld bead paths;

[0085] 4-1) Assuming that the weld type in step 1) is a continuous weld of straight line-straight line, set point A as the starting point of the first straight line, point B as the ending point of the first straight line and the starting point of the second straight line, and point C as the ending point of the second straight line;

[0086] 4-2) The following is a set of root weld points that were welded and recorded:

[0087] The set of points along line AB is:

[0088] The set of points along line BC is:

[0089] in, Indicates the first root weld bead in the set of root weld bead locations. The pose of a point, expressed in Euler angles, is as follows:

[0090] , ;

[0091] 4-3) The set offset of the cover weld bead is expressed as:

[0092] S

[0093] in These represent the translational offset of the covering weld bead relative to the root weld bead position in the X, Y, and Z axes of the weld coordinate system, respectively. These represent the rotation angles of the welding torch posture around the X, Y, and Z axes of the weld coordinate system, respectively.

[0094] The offset can then be represented by the transformation matrix as follows:

[0095]

[0096] in, For the reason The rotation matrix formed, where t is the translation vector, is denoted as:

[0097] 4-4) Calculate the coverage weld points based on the offset. Note that the X-direction offset only applies to the arc initiation and extinguishing points, therefore it needs to be handled separately from the Y and Z-direction offsets.

[0098] Methods for calculating offsets in the Y and Z directions:

[0099] ,

[0100] in, The first point in the set of root weld points in the robot base coordinate system point; This is the transformation matrix of the weld coordinate system in the robot base coordinate system; To cover the weld bead offset transformation matrix, the translation vector is denoted as: ; The first weld bead point in the set of root weld bead points in the desired robot base coordinate system. The point corresponds to the weld bead coverage point.

[0101] bX direction offset calculation method:

[0102] The rules for handling X-direction offset are as follows: If The coverage weld extends from the root weld at both ends; if If so, then shorten it.

[0103] set up Let be the first point of the set of points along line AB; Let be the tail point of the set of points along line BC; Let be the unit vector in the direction of line AB; Let be the unit vector along the direction of line BC. The specific calculation process is as follows:

[0104] when hour:

[0105]

[0106]

[0107] Will and Insert the beginning and end of the set of covered weld points respectively, as the start and end points of the covered weld points based on the extension points of the root weld.

[0108] when hour:

[0109] Based on the set of points along line AB, starting from the first point Traverse backwards and calculate the current point. arrive distance ,like Then adjust the point as follows:

[0110]

[0111] Based on the set of points along line BC, starting from the tail point Traverse forward and calculate the current point. arrive distance ,like Then adjust the point as follows:

[0112]

[0113] Will As the first point of the set of weld bead points covered by straight line AB. As the tail point of the set of weld bead points covered by straight line BC, and respectively removed from the original set. Previously and The next points.

[0114] For circular arc welds, the calculation method for the offset in the X direction is the same: extend or shorten along the tangent of the arc.

[0115] Finally, by combining the above processing methods, a complete set of offset points for the covered weld bead is obtained.

[0116] 5) Recalculate the offset point of the cover weld at the intersection of continuous welds, and shorten or extend it accordingly along the welding direction;

[0117] 5-1) Recalculate the offset point of the cover weld bead corresponding to the intersection of the two straight lines. The specific process is as follows:

[0118] a) Calculate the direction vectors of lines AB and BC. and The included angle ;

[0119] b) with Establish a new coordinate system for the weld at the intersection point, using the X-axis as the coordinate axis. ;

[0120] c) Adjust the offset S at the intersection point. The value is calculated using the following formula:

[0121]

[0122] at this time, The translation vector is: ;

[0123] d) Recalculate the locations of the covered weld beads at the intersection:

[0124]

[0125] 5-2) Identify and remove abnormal weld bead coverage points near the intersection. The implementation method is as follows:

[0126] From the intersection Traverse the root weld bead point set forward and calculate the distance from each traversed point to the root weld bead point. distance And the corresponding covered weld points to distance If the current traversal point satisfies:

[0127] and

[0128] in, If the covered weld bead is not found, it will be considered an abnormal point and removed.

[0129] Similarly, from Traverse backwards and remove outliers.

[0130] Finally, as described in step 6), all covered weld points are added to the robot motion queue in sequence to perform covered weld welding and complete the multi-layer, multi-pass welding process.

[0131] The automatic welding method of the present invention will be further described below with reference to Example 1.

[0132] Example 1:

[0133] like Figure 1 The image shows an example of a calculation method for multi-layer, multi-pass covering weld paths in a straight-line weld type within a continuous weld type. The overall process is as follows: Figure 2 As shown, it includes the following steps:

[0134] S1: The weld is composed of straight lines AB and BC. The position data of three points A, B, and C of the weld and the attitude of the welding gun are obtained by teaching or scanning the weld with a 3D vision sensor.

[0135] S2: Set the cover weld offset, root weld point recording interval, and other relevant welding parameters to create a multi-layer, multi-pass welding operation. Begin welding the root weld and record the discrete points of the root weld in real time:

[0136] The set of root weld points in section AB is denoted as:

[0137] The set of root weld points in section BC is denoted as:

[0138] S3: For each point in the root weld set, based on the set welding reference plane and the straight line direction vector, establish the weld coordinate system corresponding to the current point, and obtain the transformation matrix relative to the robot base coordinate system. ;

[0139] S4: Calculate the set of path points for all covered welds based on the root weld record points and the set offset. Figure 1 This is a schematic diagram of the XY section of the weld coordinate system. Taking the calculation of the covered weld bead A`B`-B`C` as an example, the calculation process is explained:

[0140] (1) Given the offset S ,in These represent the translational offset of the covering weld bead relative to the root weld bead position in the X, Y, and Z axes of the weld coordinate system, respectively. These represent the rotation angles of the welding torch posture around the X, Y, and Z axes of the weld coordinate system, respectively.

[0141] The transformation matrix corresponding to the offset is then expressed as:

[0142]

[0143] in, For the reason The rotation matrix formed, where t is the translation vector, is denoted as: ;

[0144] (2) The calculation methods for the offsets in the Y and Z directions are as follows:

[0145] ,

[0146] in, The first point in the set of root weld points in the robot base coordinate system point; This is the transformation matrix of the weld coordinate system in the robot base coordinate system; To cover the weld bead offset transformation matrix, the translation vector is denoted as: ; The first weld bead point in the set of root weld bead points in the desired robot base coordinate system. The point corresponds to the weld bead coverage point.

[0147] (3) The method for calculating the offset in the X direction is as follows:

[0148] The rules for handling X-direction offset are as follows: If The coverage weld extends from the root weld at both ends; if If so, then shorten it. (Legend is known.) , The unit vector in the direction of line AB ; The unit vector in the direction of line BC The specific calculation process is as follows:

[0149] Based on the set of points along line AB, starting from the first point Traverse backwards and calculate the current traversal point. arrive distance If the current traversal point satisfies: Then adjust the point as follows:

[0150]

[0151] Based on the set of points along line BC, starting from the tail point Traverse forward and calculate the current traversal point. arrive distance If the current traversal point satisfies: Then adjust the point as follows:

[0152]

[0153] Will As the first point of the set of weld bead points covered by straight line AB. As the tail point of the set of weld points covered by straight line BC, and respectively discarded Previously and The next points.

[0154] S5: Recalculate the offset point of the cover weld at the intersection of the two straight lines, as follows:

[0155] (1) Calculate the direction vectors of lines AB and BC. and The included angle ;

[0156] (2) with Establish a new coordinate system for the weld at the intersection point, using the X-axis as the coordinate axis. ;

[0157] (3) Adjust the offset S at the intersection point. value:

[0158]

[0159] at this time, The translation vector is:

[0160] (4) Recalculate the locations of the weld beads at the intersection:

[0161]

[0162] (5) Identify and remove abnormal weld bead coverage points near the intersection:

[0163] From the intersection Traverse the root weld bead point set forward and calculate the distance from each traversed point to the root weld bead point. distance And the corresponding covered weld points to distance If the current traversal point satisfies:

[0164] and

[0165] in, If the covered weld bead is not found, it will be considered an abnormal point and removed.

[0166] Similarly, from Traverse backwards and remove outliers.

[0167] (6) Obtain the set of path points that ultimately cover weld A`B`-B`C`:

[0168] Section A`B`:

[0169] Section B`C`:

[0170] The calculation method for the remaining covered weld paths (such as A``B``- B``C``, etc.) is the same.

[0171] S6: Add all covered weld points to the robot motion queue in sequence, perform covered weld welding, and complete the multi-layer, multi-pass welding process.

[0172] Figure 3 and Figure 4 Examples of calculation methods for multi-layer, multi-pass weld paths in straight-to-circular arc welds and circular arc-to-circular arc welds are presented respectively. The main difference between the circular arc path calculation and the straight-line calculation lies in the determination of the welding direction vector: the welding direction of the circular arc segment is the tangent direction at that point. The remaining related calculation methods and steps are consistent with the aforementioned straight-to-straight weld example and will not be repeated here.

[0173] In summary, the automated multi-layer, multi-pass welding method for continuous weld seams in industrial robots provided by this invention innovatively integrates real-time path recording, dynamic coordinate system construction, automatic path offset calculation based on mathematical transformation, and intelligent optimization processing for the intersections of continuous weld seams, constructing a complete, efficient, and reliable automated welding path generation solution. This method not only overcomes the inherent defects of traditional manual teaching, such as low efficiency and poor consistency, but also crucially solves the core technical bottleneck of existing automatic offset technologies being unable to adapt to complex continuous weld seams and prone to discontinuities and interference at corners. The implementation of this invention will strongly promote the development of robotic welding processes towards higher levels of automation, intelligence, and flexibility, providing solid technical support for improving welding quality, production efficiency, and process reliability in high-end equipment manufacturing, and possesses significant industrial application value and broad market prospects.

[0174] Those skilled in the art will understand that the above description is merely a preferred embodiment of the present invention, and the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. This is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0175] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A method for automated multi-layer, multi-pass continuous weld seam welding using an industrial robot, characterized in that, Includes the following steps: Step S1: Obtain multi-layer, multi-pass weld information of the workpiece to be welded; the weld information includes: weld type and pose data of the start and end points of each weld; Step S2: Control the industrial robot to weld the root weld and record the discrete points on the root weld path in real time according to the set recording interval; Step S3: Based on the preset welding reference plane normal vector, welding direction vector and the currently recorded root weld point, establish the weld coordinate system and determine the transformation matrix of the weld coordinate system relative to the robot base coordinate system. Step S4: Calculate the set of path points corresponding to all covered welds based on the discrete points recorded in the root weld and the preset offset of the covered weld. Step S4 includes the following steps: Step 41: The preset offset S of the covered weld bead is expressed as: in These represent the translational offset of the covering weld bead relative to the root weld bead position in the X, Y, and Z axes of the weld coordinate system, respectively. These represent the rotation angles of the welding torch posture around the X, Y, and Z axes of the weld coordinate system, respectively. Step 42: Determine the corresponding transformation matrix for: ； in, For the reason The rotation matrix formed, Translation vector ; Step 43: Calculate the coverage weld points based on the offset; Step S5: When the weld type is a continuous weld containing two or more continuous welds, recalculate the offset point of the covering weld at the intersection of adjacent welds, and judge and remove abnormal covering weld points near the intersection. In step S5, the recalculation of the offset point of the covering weld bead at the intersection of adjacent weld seams specifically includes: Step S51: Calculate the two weld direction vectors at the intersection point. and The included angle ; Step S52: with With the direction of the X-axis, re-establish the weld coordinate system at the intersection point; Step S53: Adjust the Y-axis offset of the weld bead covering the intersection point as follows: ； Step S54: Using the adjusted offset, combined with the current situation, Translation vector Recalculate the corresponding cover weld points at the intersection. for: ； in, The root weld point at the intersection. To use the adjusted Y-axis offset The offset transformation matrix; This is the transformation matrix of the weld coordinate system in the robot base coordinate system; In step S5, the judgment and removal of abnormal weld bead coverage points near the intersection specifically includes: Set distance threshold From the intersection Traverse the root weld bead point set forward and backward respectively. For each traversed point, calculate its distance to the root weld bead. distance And its corresponding covered weld points to distance If both conditions are met and If so, the covered weld bead point is determined to be an abnormal point and is removed; Step S6: Add all the processed cover weld path point sets to the robot motion queue in sequence, and control the industrial robot to perform cover weld welding.

2. The method for automatic multi-layer, multi-pass continuous weld seam welding of an industrial robot according to claim 1, characterized in that, In step S1, the weld type includes single weld and continuous weld; The single weld seam refers to a weld seam consisting of only one straight line or one circular arc weld seam welded in a single arc initiation; The continuous weld refers to the welding of two or more continuous welds completed in one arc initiation, specifically including straight-to-straight welds, straight-to-circular arc welds, and circular arc-to-circular arc welds; The pose data is acquired through robot teaching or scanning with a 3D vision sensor.

3. The method for automatic multi-layer, multi-pass continuous weld seam welding of an industrial robot according to claim 1, characterized in that, Step S2 specifically includes: Step S21: Set welding parameters, including weld information, number of welding layers, number of weld passes per layer, offset of each covering weld pass relative to the root weld pass, and interval distance for recording root weld pass path points. Step S22: Transmit welding parameters to the robot controller to create a welding job; Step S23: Control the robot to weld the root weld and record the discrete points on the root weld path in real time according to the recorded interval.

4. The method for automatic multi-layer, multi-pass continuous weld seam welding of an industrial robot according to claim 1, characterized in that, Step S3 specifically includes: The origin is the current root weld bead recording point, the X-axis is the welding direction vector, and the Z-axis is the welding reference plane normal vector. For straight welds, the welding direction vector is a vector pointing from the starting point to the ending point; For circular arc welds, the welding direction vector is the tangent direction vector of the circular arc at the recording point.

5. The method for automatic multi-layer, multi-pass continuous weld seam welding of an industrial robot according to claim 1, characterized in that, Step S43 specifically includes: a) Calculate the points corresponding to the offset of the cover weld bead in the Y-axis and Z-axis directions. for: ； in, The first point in the set of root weld points in the robot base coordinate system point, Offset transformation matrix The matrix that retains only the translation components in the Y and Z directions has the following translation vector: ; This is the transformation matrix of the weld coordinate system in the robot base coordinate system; b) X-direction offset calculation method: Processing X-axis offset :like Then the cover weld bead extends along the welding direction based on the root weld bead at the start and end points; if If so, then shorten it; For straight-line continuous welds and In the case of shortening, the shortening process specifically includes: Let the first point of the root weld bead location set of the first straight line segment be... The end point of the root weld point set of the second straight segment, which is continuous with the first straight segment, is... , Let be the unit vector in the direction of the first line segment. The unit vector in the direction of the second line segment; In the set of points on the first straight line segment, from Traverse backwards, when the traversal point is reached arrive distance When, adjust this point to and with the adjusted This serves as the actual starting point for the covered weld bead; In the set of points on the second straight line segment, from Traverse forward, when the traversal point arrive distance When, adjust this point to and with the adjusted This serves as the actual endpoint of the covered weld bead.

6. The welding system of the continuous multi-layer multi-pass automatic welding method for industrial robots according to claim 1, characterized in that, include: The information acquisition module is used to acquire multi-layer, multi-pass weld information of the workpiece to be welded. The weld information includes the weld type and the positional data of the start and end points of each weld. The root weld welding and recording module is used to control the industrial robot to weld the root weld and record the discrete points on the root weld path in real time according to the set recording interval. The coordinate system processing module is used to establish a weld coordinate system based on the preset welding reference plane normal vector and welding direction vector, with the currently recorded root weld point as the origin, and to determine the transformation matrix of the weld coordinate system relative to the robot base coordinate system. The path calculation module is used to calculate the set of path points corresponding to all covered welds based on the discrete points recorded in the root weld and the preset offset of the covered weld. The intersection optimization module is used to recalculate the offset point of the covered weld bead at the intersection of adjacent welds when the weld type contains two or more continuous welds, and to judge and remove abnormal covered weld bead points near the intersection. The motion control module is used to add all the processed cover weld path points to the robot motion queue in sequence, and control the industrial robot to perform cover weld welding.

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