Automatic positioning welding method, system and storage medium

Abstract

This application discloses an automatic positioning welding method, system, and storage medium, relating to the field of industrial automation technology and applicable to welding robots. The method comprises: obtaining first coordinates of multiple welding teaching points of a workpiece to be welded in a robot coordinate system before performing a spot welding operation; establishing a reference coordinate system based on the first coordinates, and obtaining second coordinates corresponding to each first coordinate in the reference coordinate system; calculating the starting point reference coordinates and the end point reference coordinates of the workpiece to be welded based on the second coordinates; after performing the spot welding operation, re-obtaining third coordinates corresponding to each welding teaching point in the robot coordinate system; and establishing a positioning coordinate system based on the third coordinates, and obtaining fourth coordinates corresponding to each third coordinate in the positioning coordinate system. This application can improve welding efficiency while ensuring welding accuracy.

Description

Technical Field

[0001] The present application relates to the field of industrial automation technology, and in particular to an automatic positioning welding method, system and storage medium. Background Art

[0002] Welding robots are industrial robots engaged in welding. They can accurately perform automatic welding according to taught movements. They are widely used in many technical fields such as weld tracking, offline programming, path planning, and intelligent control.

[0003] In the related technology, when welding a V-groove, the operator needs to first perform spot welding on the welding workpiece to complete pre-welding, and then the welding robot needs to weld the entire weld bead on the welding workpiece according to the pre-learned teaching trajectory to complete the entire welding operation. When the operator spot welds the welding workpiece, it often causes the welding workpiece to deform, resulting in an increased complexity in teaching the teaching trajectory and teaching posture of the welding robot during the teaching process. The teaching trajectory and teaching posture of the welding robot need to be repeatedly modified to achieve the desired effect, which consumes a lot of time, reduces welding efficiency, and cannot guarantee the welding accuracy of the weld. How to improve welding efficiency while ensuring welding accuracy is an issue that urgently needs to be discussed and resolved. Summary of the Invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes an automatic positioning welding method, system and storage medium, which can improve welding efficiency while ensuring welding accuracy.

[0005] In order to solve the above technical problems, this application proposes the following technical solutions:

[0006] The first embodiment of the present application provides an automatic positioning welding method, which is applied to a welding robot, comprising:

[0007] Before performing the spot welding operation, first coordinates of multiple welding teaching points of the workpiece to be welded are obtained in the robot coordinate system; a reference coordinate system is established based on the first coordinates, and second coordinates corresponding to each of the first coordinates in the reference coordinate system are obtained; and the starting point reference coordinates and the ending point reference coordinates of the workpiece to be welded are calculated based on the second coordinates;

[0008] After performing the spot welding operation, reacquiring the third coordinates of the plurality of welding teaching points corresponding one to one in the robot coordinate system; establishing a positioning coordinate system based on the third coordinates, and obtaining the fourth coordinates of each of the third coordinates corresponding one to one in the positioning coordinate system;

[0009] Calculating a transformation matrix between the reference coordinate system and the positioning coordinate system according to the fourth coordinate and the second coordinate;

[0010] Calculating the first starting point positioning coordinates and the first ending point positioning coordinates in the positioning coordinate system according to the conversion matrix, the starting point reference coordinates and the ending point reference coordinates;

[0011] Calculate the second starting point positioning coordinates and the second end point positioning coordinates of the workpiece to be welded according to the fourth coordinates;

[0012] Calculating the calibration starting point positioning coordinates according to the first starting point positioning coordinates and the second starting point positioning coordinates;

[0013] Calculating the calibration endpoint positioning coordinates according to the first endpoint positioning coordinates and the second endpoint positioning coordinates;

[0014] A welding operation is performed on the workpiece weld according to the calibration starting point positioning coordinates and the calibration end point positioning coordinates.

[0015] The automatic positioning welding method according to the embodiment of the first aspect of the present application has at least the following beneficial effects: the coordinate system before deformation with the workpiece to be welded as the reference object is determined by the reference coordinate system, and the coordinate system after deformation with the workpiece to be welded as the reference object is determined by the positioning coordinate system, so that the offset before spot welding and after electric welding is determined by the welding teaching point at a fixed position, so that the actual starting point and end point of the weld can be determined, and the starting point and end point of the weld are calibrated based on the starting point reference coordinates and end point reference coordinates in the reference coordinate system, the second starting point positioning coordinates and the second end point positioning coordinates in the positioning coordinate system, so as to further ensure the accuracy of the weld starting point and the weld end point. At this time, spot welding can be performed based on the teaching trajectory and teaching posture of the weld starting point and the weld end point of the welding clamp, and the desired effect can be achieved without repeatedly modifying the teaching trajectory and teaching posture of the welding robot, which can improve welding efficiency while ensuring welding accuracy.

[0016] According to some embodiments of the first aspect of the present application, the first coordinates include two first point sets; the two first point sets respectively correspond to coordinate sets of at least two welding teaching points on two intersection lines passing through the weld start point or the weld end point; and establishing a reference coordinate system based on the first coordinates includes:

[0017] Constructing a first teaching straight line on any side of the workpiece to be welded, wherein the first teaching straight line is parallel to a vector from the welding start point to the welding end point;

[0018] Select multiple points on the first teaching line to obtain a third point set;

[0019] Constructing a second teaching line parallel to the first teaching line on any side of the workpiece to be welded, and selecting a plurality of points on the second teaching line to obtain a fourth point set;

[0020] Determine a third coordinate axis point based on the fourth point set, obtain a first perpendicular line that is perpendicular to the first teaching straight line and passes through the third coordinate axis point, and use the intersection of the first perpendicular line and the first teaching straight line as the origin of the reference coordinate system;

[0021] determining a first axis vector of the reference coordinate system according to one of the first point sets;

[0022] determining a second axis vector perpendicular to the first axis vector in the reference coordinate system according to another first point set and the first axis vector;

[0023] determining a third axis vector from the first axis vector and the second axis vector;

[0024] The reference coordinate system is obtained according to the origin of the reference coordinate system, the first axis vector, the second axis vector, and the third axis vector.

[0025] According to some embodiments of the first aspect of the present application, the third coordinates include two fifth point sets; the two fifth point sets respectively correspond one-to-one to coordinate sets of at least two welding teaching points on two intersection lines passing through the weld start point or the weld end point; and establishing a positioning coordinate system based on the third coordinates includes:

[0026] Constructing a third teaching straight line on any side of the workpiece to be welded, wherein the third teaching straight line is parallel to a vector from the welding start point to the welding end point;

[0027] Selecting multiple points on the third teaching straight line to obtain a seventh point set;

[0028] Constructing a fourth teaching line parallel to the third teaching line on any side of the workpiece to be welded, and selecting a plurality of points on the fourth teaching line to obtain an eighth point set;

[0029] Determine a fourth coordinate axis point based on the eighth point set, obtain a second perpendicular line that is perpendicular to the third teaching straight line and passes through the fourth coordinate axis point, and use the intersection of the second perpendicular line and the third teaching straight line as the origin of the positioning coordinate system;

[0030] Determine a fourth axis vector of the positioning coordinate system according to one of the fifth point sets;

[0031] determining a fifth axis vector perpendicular to the fourth axis vector in the positioning coordinate system according to another fifth point set and the fourth axis vector;

[0032] determining a sixth axis vector from the fourth axis vector and the fifth axis vector;

[0033] The positioning coordinate system is obtained according to the origin of the positioning coordinate system, the fourth axis vector, the fifth axis vector and the sixth axis vector.

[0034] According to some embodiments of the first aspect of the present application, calculating the calibration starting point positioning coordinates according to the first starting point positioning coordinates and the second starting point positioning coordinates includes:

[0035] Calculating an average of the first starting point positioning coordinates and the second starting point positioning coordinates to obtain the calibration starting point positioning coordinates;

[0036] The step of calculating the calibration endpoint positioning coordinates according to the first endpoint positioning coordinates and the second endpoint positioning coordinates includes:

[0037] An average value of the first end point positioning coordinate and the second end point positioning coordinate is calculated to obtain the calibration end point positioning coordinate.

[0038] According to some embodiments of the first aspect of the present application, the second coordinates include two ninth point sets and two tenth point sets; the two ninth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on two intersection lines passing through the starting point of the weld; the two tenth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on two intersection lines passing through the end point of the weld; and the starting point reference coordinates and the end point reference coordinates of the workpiece to be welded are calculated based on the second coordinates, including:

[0039] Calculate the first common perpendicular line of the two intersection lines corresponding to the ninth point set;

[0040] Calculate the starting point reference coordinates based on the first common perpendicular line and the ninth point set;

[0041] Calculate the second common perpendicular line of the two intersection lines corresponding to the tenth point set;

[0042] Calculate the end point reference coordinates based on the second common perpendicular line and the tenth point set;

[0043] The fourth coordinates include two eleventh point sets and two twelfth point sets; the two eleventh point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on the two intersection lines passing through the weld start point; the two twelfth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on the two intersection lines passing through the weld end point; the second starting point positioning coordinates and the second end point positioning coordinates of the workpiece to be welded are calculated based on the fourth coordinates, including:

[0044] Calculate the third common perpendicular line of the two intersection lines corresponding to the eleventh point set;

[0045] Calculating the second starting point positioning coordinates based on the third common perpendicular line and the eleventh point set;

[0046] Calculate the fourth common perpendicular line of the two intersection lines corresponding to the twelfth point set;

[0047] The second end point positioning coordinates are calculated based on the fourth common perpendicular and the twelfth point set.

[0048] According to some embodiments of the first aspect of the present application, the welding operation includes:

[0049] Collecting the current sampling signal of the welding robot during the weaving welding process from the calibration starting point positioning coordinate to the calibration end point positioning coordinate according to a preset sampling period;

[0050] Performing a filtering operation on the current sampling signal in the current sampling period to obtain a filtered current signal;

[0051] Integrate the filtered current signal to obtain the sampled current integral;

[0052] Obtaining the swing amplitude of the welding robot in the current sampling period, and obtaining a compensation direction and a compensation value corresponding to the compensation direction according to the sampling current integral of the current sampling period, the sampling current integral of the previous sampling period, and the swing amplitude;

[0053] The welding gun of the welding robot is compensated according to the compensation value and the compensation direction.

[0054] According to some embodiments of the first aspect of the present application, filtering the current sampling signal in the current sampling period to obtain a filtered current signal includes:

[0055] Performing median filtering on the current sampling signal in the current sampling period to obtain a median filtered signal;

[0056] The high-frequency noise in the median filter signal is filtered out by using a preset cutoff frequency and sampling frequency to obtain the filtered current signal.

[0057] According to some embodiments of the first aspect of the present application, the compensation direction includes a first compensation direction and a second compensation direction, and obtaining the compensation direction and the compensation value corresponding to the compensation direction based on the sampling current integral of the current sampling period, the sampling current integral of the previous sampling period, and the swing amplitude includes:

[0058] Compare the sampling current integral of the current sampling period with the sampling current integral of the previous sampling period to obtain the sampling period with the larger sampling current integral;

[0059] Obtaining the swing direction of the welding gun end during the sampling period in which the sampling current integral is larger, when the swing direction of the welding gun end is left, the first compensation direction is right; when the swing direction of the welding gun end is right, the first compensation direction is left;

[0060] Calculating the sampling current integral of the current sampling period, the sampling current integral of the previous sampling period, and the swing amplitude to obtain a compensation value corresponding to the first compensation direction;

[0061] Calculate the sum of the sampling current integral of the current sampling period and the sampling current integral of the previous sampling period to obtain the sampling current integral sum;

[0062] comparing a preset reference current total value with the integrated sum of the sampled currents; when the integrated sum of the sampled currents is greater than the reference current total value, the second compensation direction is upward; and when the integrated sum of the sampled currents is less than the reference current total value, the second compensation direction is downward;

[0063] The total value of the reference current and the integral sum of the sampled current are calculated to obtain a compensation value corresponding to the second compensation direction.

[0064] A second embodiment of the present application provides an automatic positioning welding system, comprising:

[0065] at least one memory;

[0066] at least one processor;

[0067] at least one program;

[0068] The programs are stored in the memory, and the processor executes at least one of the programs to implement:

[0069] An automatic positioning welding method as described in any one of the first aspects of the present application.

[0070] A third aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer-executable signal, wherein the computer-executable signal is used to execute:

[0071] An automatic positioning welding method as described in any one of the first aspects of the present application.

[0072] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Additional aspects and advantages of the present application will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0074] Figure 1 A main flow chart of the automatic positioning welding method provided in some embodiments of the present application;

[0075] Figure 2 A schematic diagram of a robot coordinate system provided for some embodiments of the present application;

[0076] Figure 3 Schematic diagram of a reference coordinate system and a positioning coordinate system provided in some embodiments of the present application;

[0077] Figure 4 A schematic diagram of an automatic positioning welding method provided in some embodiments of the present application;

[0078] Figure 5 A schematic diagram of a current sampling signal provided by another embodiment of the present application;

[0079] Figure 6 A module block diagram of an automatic positioning welding system provided in some embodiments of the present application. DETAILED DESCRIPTION

[0080] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0081] It should be noted that although a logical order is shown in the flowcharts, in some cases, the steps shown or described may be performed in a different order than that shown in the flowcharts. Terms used in the specification, claims, and drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0082] In the description of this application, if there is a description of first or second, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0083] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0084] Welding robots are industrial robots that perform welding and can accurately perform automatic welding according to the taught movements. They are widely used in multiple technical fields such as weld tracking, offline programming, path planning, and intelligent control. In related technologies, when welding a V-groove, the operator must first perform spot welding on the workpiece to complete the pre-welding process. The welding robot then welds the entire weld bead according to the pre-learned teaching trajectory to complete the entire welding operation. However, when the operator spot welds the workpiece, the welded workpiece often deforms, which increases the complexity of the welding robot's teaching trajectory and teaching posture during the teaching process. The welding robot's teaching trajectory and teaching posture need to be repeatedly modified to achieve the desired effect, which consumes a lot of time, reduces welding efficiency, and cannot guarantee the welding accuracy of the weld bead. How to improve welding efficiency while ensuring welding accuracy is an issue that urgently needs to be discussed and resolved.

[0085] Based on this, the automatic positioning welding method of the present application can improve welding efficiency while ensuring welding accuracy.

[0086] Reference Figure 1 In the first aspect, an embodiment of the present application provides an automatic positioning welding method, which is applied to a welding robot, including but not limited to steps S110, S120, S130, S140, S150, S160, S170, and S180.

[0087] S110, before performing the spot welding operation, obtaining first coordinates of multiple welding teaching points of the workpiece to be welded in the robot coordinate system; establishing a reference coordinate system based on the first coordinates, and obtaining second coordinates corresponding to each first coordinate in the reference coordinate system; and calculating the starting point reference coordinates and the ending point reference coordinates of the workpiece to be welded based on the second coordinates;

[0088] S120, after performing the spot welding operation, reacquire the third coordinates of the plurality of welding teaching points corresponding one to one in the robot coordinate system; establish a positioning coordinate system based on the third coordinates, and obtain the fourth coordinates of each third coordinate corresponding one to one in the positioning coordinate system;

[0089] S130, calculating a conversion matrix between the reference coordinate system and the positioning coordinate system according to the fourth coordinate and the second coordinate;

[0090] S140, calculating a first starting point positioning coordinate and a first ending point positioning coordinate in a positioning coordinate system according to the conversion matrix, the starting point reference coordinate and the ending point reference coordinate;

[0091] S150, calculating the second starting point positioning coordinates and the second end point positioning coordinates of the workpiece to be welded according to the fourth coordinates;

[0092] S160, calculating the calibration starting point positioning coordinates according to the first starting point positioning coordinates and the second starting point positioning coordinates;

[0093] S170, calculating the calibration end point positioning coordinates according to the first end point positioning coordinates and the second end point positioning coordinates;

[0094] S180: Perform a welding operation on the workpiece weld according to the calibration starting point positioning coordinates and the calibration end point positioning coordinates.

[0095] It should be noted that the coordinate system before deformation with the workpiece to be welded as the reference object is determined by the reference coordinate system, and the coordinate system after deformation with the workpiece to be welded as the reference object is determined by the positioning coordinate system, so that the offset before spot welding and after electric welding is determined by the welding teaching point at a fixed position, so that the actual starting point and end point of the weld can be determined, and the starting point and end point of the weld are calibrated based on the starting point reference coordinates and end point reference coordinates in the reference coordinate system, and the second starting point positioning coordinates and second end point positioning coordinates in the positioning coordinate system, so as to further ensure the accuracy of the weld starting point and end point. At this time, spot welding can be performed based on the teaching trajectory and teaching posture of the weld starting point and weld end point of the un-electric welding clamp, and the desired effect can be achieved without repeatedly modifying the teaching trajectory and teaching posture of the welding robot, which can improve welding efficiency while ensuring welding accuracy.

[0096] It should be noted that this application is only applicable to workpieces with a thickness greater than or equal to 8 mm. Workpieces with a thickness less than 8 mm may be difficult to locate during positioning due to their thinness.

[0097] Reference Figure 2 and Figure 3 The core idea of ​​this application is: first, obtain the starting point and end point of the weld of the workpiece to be welded, determine multiple welding teaching points based on the starting point and end point of the weld of the workpiece to be welded, and calculate the welding teaching points through the four-point method in the subsequent welding process to locate the starting point and end point of the weld (because the workpiece to be welded may be displaced and deformed after the spot welding operation is completed, which makes it impossible to successfully find the starting point and end point of the weld, so it is necessary to relocate the starting point and end point of the weld according to the welding teaching points after the spot welding operation is performed). Secondly, after the spot welding operation is performed, the offset and rotation of the two-dimensional plane of the workpiece to be welded is located by the three-point method, and the starting point and end point of the workpiece to be welded are offset according to the transformation matrix calculated according to the reference coordinates and the positioning coordinate system, and finally arc tracking is used to complete the welding of the weld of the workpiece to be welded.

[0098] It should be noted that the robot coordinate system in this application is the world coordinate system, and the coordinate origin of the robot coordinate system is the base of the welding robot.

[0099] It can be understood that the first coordinate includes two first point sets; the two first point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on two intersection lines passing through the starting point or the end point of the weld; establishing a reference coordinate system based on the first coordinates, including: constructing a first teaching straight line on any side of the workpiece to be welded, wherein the first teaching straight line is parallel to the vector from the welding start point to the welding end point; selecting multiple points from the first teaching straight line to obtain a third point set; constructing a second teaching straight line parallel to the first teaching straight line on any side of the workpiece to be welded, and selecting multiple points from the second teaching straight line to obtain a fourth point set; determine the third coordinate axis point based on the fourth point set, obtain a first perpendicular line that is perpendicular to the first teaching straight line and passes through the third coordinate axis point, and use the intersection of the first perpendicular line and the first teaching straight line as the origin of the reference coordinate system; determine the first axis vector of the reference coordinate system based on one of the first point sets; determine the second axis vector that is perpendicular to the first axis vector in the reference coordinate system based on the other first point set and the first axis vector; determine the third axis vector from the first axis vector and the second axis vector; obtain the reference coordinate system based on the origin, the first axis vector, the second axis vector and the third axis vector of the reference coordinate system.

[0100] Reference Figure 2 For example, assume that the workpiece to be welded is a V-groove workpiece with a thickness greater than or equal to 8 mm, and one side of the V-groove workpiece is placed parallel to the horizontal plane. First, obtain the position of the weld starting point and the position of the weld end point of the V-groove workpiece, and then determine two intersection lines based on the weld starting point and the weld end point. These two intersection lines can be arbitrarily selected as long as the intersection of the two intersection lines is the weld starting point / weld end point. Then, extract four points P1, P2, P3, and P4 on the intersection line with the weld starting point as the intersection point, where P1 and P2 constitute a first point set, and P3 and P4 constitute another first point set. Extract four points P5, P6, P7, and P8 on the intersection line with the weld end point as the intersection point, where P5 and P6 constitute a second point set, and P7 and P8 constitute another second point set. Furthermore, 6 points or 8 points can also be extracted on the intersection line with the weld starting point as the intersection point, as long as the positions of the extracted points are all on the intersection line.

[0101] Secondly, a first teach line parallel to the vector from the weld start point to the weld end point is constructed on any side of the V-groove workpiece. D1 and D2 are extracted from this first teach line to form the third point set. Furthermore, a second teach line is located on the V-groove workpiece, ensuring that it is parallel to the first teach line. The preparation point for D3, the starting point for D3, and D3 are extracted from this second teach line to form the fourth point set. The first coordinate system includes the first, second, third, and fourth point sets.

[0102] Furthermore, P1, P2, P3, P4, P5, P6, P7, P8, D1, D2 and D3 can also be understood as the coordinates of the welding teaching points in the robot coordinate system. The origin of the robot coordinate system is the base of the welding robot. Here, the coordinates of the welding teaching points in the robot coordinate system are marked as B{ B P1, B P2, B P3 B P4, B D1, B D2, B D3}.

[0103] For example, refer to Figure 3 , Figure 3 The solid line portion in the figure represents the coordinate position of the workpiece to be welded, the coordinate position of the welding teaching point, the coordinate position of the weld start point, and the coordinate position of the weld end point in the robot coordinate system before the spot welding operation is performed, wherein P1 and P2 constitute a first point set, P3 and P4 constitute another first point set, P5 and P6 constitute a second point set, and P7 and P8 constitute another second point set. The first coordinate axis point is D1, the second coordinate axis point is D2, D1 and D2 constitute the third point set, the third coordinate axis point is D3, and the fourth point set includes D3. Assuming that the robot coordinate system in this application is {B}, then B P1 is the coordinate of P1 in the robot coordinate system, B P 12 It is the vector formed by P1 and P2 in the robot coordinate system. The coordinates and vectors of other welding teaching points in the robot coordinate system are the same.

[0104] First, determine a straight line D12 from D1 and D2, and use the intersection of the perpendicular line from D3 to D12 as the origin of the reference coordinate system {TB} TB O, with TB X= B P2- B P1 is the X-axis direction component of the reference coordinate system {TB}, that is, the first axis vector. TB Z= B P 12 × B P 34 As the Z-axis direction component of the reference coordinate system {TB}, that is, the second axis vector, because the coordinate axes of the coordinate system are perpendicular to each other, the Y-axis direction component of the reference coordinate system {TB} is TB Y= TB X× TB Z, the third axis vector.

[0105] Furthermore, the reference coordinate system {TB} can be established based on the origin of the reference coordinate system {TB}, the first axis vector, the second axis vector and the third axis vector of the reference coordinate system {TB}. Then, the second coordinates of the welding teaching points P1, P2, P3, P4, P5, P6, P7, P8, D1, D2 and D3 corresponding to each other in the reference coordinate system {TB} are determined, wherein the second coordinates include TB P1, TB P2, TB P3, TB P4, TB P5, TB P6, TB P7, TB P8.

[0106] It can be understood that the third coordinate includes two fifth point sets; the two fifth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on the two intersection lines passing through the weld start point or the weld end point; establishing a positioning coordinate system based on the third coordinate, including: constructing a third teaching straight line on any side of the workpiece to be welded, wherein the third teaching straight line is parallel to the vector from the welding start point to the welding end point; selecting multiple points from the third teaching straight line to obtain a seventh point set; constructing a fourth teaching straight line parallel to the third teaching straight line on any side of the workpiece to be welded, selecting multiple points from the fourth teaching straight line and obtain the eighth point set; determine the fourth coordinate axis point according to the eighth point set, obtain the second perpendicular line that is perpendicular to the third teaching straight line and passes through the fourth coordinate axis point, and use the intersection of the second perpendicular line and the third teaching straight line as the origin of the positioning coordinate system; determine the fourth axis vector of the positioning coordinate system according to one of the fifth point sets; determine the fifth axis vector that is perpendicular to the fourth axis vector in the positioning coordinate system according to the other fifth point set and the fourth axis vector; determine the sixth axis vector from the fourth axis vector and the fifth axis vector; obtain the positioning coordinate system according to the origin, the fourth axis vector, the fifth axis vector and the sixth axis vector of the positioning coordinate system.

[0107] For example, refer to Figure 3 , Figure 3 The dotted line portion in the figure represents the coordinate position of the workpiece to be welded, the coordinate position of the welding teaching point, the coordinate position of the weld start point, and the coordinate position of the weld end point in the robot coordinate system after the spot welding operation is performed, wherein P1 and P2 constitute a first point set, P3 and P4 constitute another first point set, P5 and P6 constitute a second point set, and P7 and P8 constitute another second point set. The first coordinate axis point is D1, the second coordinate axis point is D2, D1 and D2 constitute the third point set, the third coordinate axis point is D3, and the fourth point set includes D3. Assuming that the robot coordinate system in this application is {B}, then B P1 is the coordinate of P1 in the robot coordinate system, B P 12It is the vector formed by P1 and P2 in the robot coordinate system. The coordinates and vectors of other welding teaching points in the robot coordinate system are the same.

[0108] First, determine a straight line D12 from D1 and D2, and use the intersection of the perpendicular line from D3 to D12 as the origin of the positioning coordinate system {TF} TF O, with TF X= B P2- B P1 is the X-axis direction component of the positioning coordinate system {TF}, that is, the first axis vector. TF Z= B P 12 × B P 34 As the Z-axis direction component of the positioning coordinate system {TF}, that is, the second axis vector, because the coordinate axes of the coordinate system are perpendicular to each other, the Y-axis direction component of the positioning coordinate system {TF} is TF Y= TF X× TF Z, the third axis vector.

[0109] Furthermore, the positioning coordinate system {TF} can be established based on the origin of the positioning coordinate system {TF}, the first axis vector, the second axis vector and the third axis vector of the positioning coordinate system {TF}. Then, the fourth coordinates of the welding teaching points P1, P2, P3, P4, P5, P6, P7, P8, D1, D2 and D3 corresponding to each other in the positioning coordinate system {TF} are determined, wherein the fourth coordinates include TF P1, TF P2, TF P3, TB P4, TF P4, TF P6, TF P7, TF P8.

[0110] It can be understood that the calibration starting point positioning coordinates are calculated based on the first starting point positioning coordinates and the second starting point positioning coordinates, including: calculating the average value of the first starting point positioning coordinates and the second starting point positioning coordinates to obtain the calibration starting point positioning coordinates; the calibration end point positioning coordinates are calculated based on the first end point positioning coordinates and the second end point positioning coordinates, including: calculating the average value of the first end point positioning coordinates and the second end point positioning coordinates to obtain the calibration end point positioning coordinates.

[0111] For example, after obtaining the second coordinate of the reference coordinate system {TB} TB P1, TB P2, TB P3, TB P4, TB P5, TB P6,TB P7, TB P8 and the fourth coordinate of the positioning coordinate system {TF} TF P1, TF P2, TF P3, TB P4, TF P4, TF P6, TF P7, TF After P8, the transformation matrix T = {TF} / {TB} can be calculated based on the second coordinate and the fourth coordinate. Further, the first starting point positioning coordinate can be calculated based on the transformation matrix T and the starting point reference coordinate, and the first end point positioning coordinate can be calculated based on the transformation matrix T and the end point reference coordinate, wherein the starting point reference coordinate and the end point reference coordinate are both calculated based on the second coordinate of the reference coordinate system {TB} TB P1, TB P2, TB P3, TB P4, TB P5, TB P6, TB P7, TB P8 is calculated. Secondly, according to the fourth coordinate of the positioning coordinate system {TF} TF P1, TF P2, TF P3, TB P4, TF P4, TF P6, TF P7, TF P8 calculates the second starting point positioning coordinates and the second end point positioning coordinates. Finally, to improve the welding accuracy of the starting point and end point, this application will also calculate the average of the first starting point positioning coordinates and the second starting point positioning coordinates to obtain the calibration starting point positioning coordinates, and calculate the average of the first end point positioning coordinates and the second end point positioning coordinates to obtain the calibration end point positioning coordinates. Finally, when the welding robot performs welding, it will perform welding according to the calibration starting point positioning coordinates and the calibration end point positioning coordinates.

[0112] Specifically, the fourth coordinate of the welding teaching point in the positioning coordinate system {TF} and the coordinate of the welding teaching point in the robot coordinate system are explained here in combination with the formula:

[0113] TF P1=T{TB}P1

[0114] TF P2=T{TB}P2

[0115] TF P3=T{TB}P3

[0116] TFP4=T{TB}P4

[0117] TF P5=T{TB}P5

[0118] TF P6=T{TB}P6

[0119] TF P7=T{TB}P7

[0120] TF P8=T{TB}P8

[0121] in, TF P1, TF P2, TF P3, TB P4, TF P4, TF P6, TF P7, TF P8 are the fourth coordinates of the positioning coordinate system {TF}; T is the transformation matrix between the reference coordinate system {TB} and the positioning coordinate system {TF}, P1, P2, P3, P4, P5, P6, P7 and P8 are the coordinates of the welding teaching points in the robot coordinate system; {TB}P1, {TB}P2, {TB}P3, {TB}P4, {TB}P5, {TB}P6, {TB}P7 and {TB}P8 are the second coordinates of the reference coordinate system {TB}.

[0122] It can be understood that the second coordinates include two ninth point sets and two tenth point sets; the two ninth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on the two intersection lines passing through the starting point of the weld; the two tenth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on the two intersection lines passing through the end point of the weld; calculating the starting point reference coordinates and the end point reference coordinates of the workpiece to be welded based on the second coordinates includes: calculating a first common perpendicular line of the two intersection lines corresponding to the ninth point set; calculating the starting point reference coordinates based on the first common perpendicular line and the ninth point set; calculating a second common perpendicular line of the two intersection lines corresponding to the tenth point set; and calculating the end point reference coordinates based on the second common perpendicular line and the tenth point set;

[0123] The fourth coordinate includes two eleventh point sets and two twelfth point sets; the two eleventh point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on the two intersection lines passing through the starting point of the weld; the two twelfth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on the two intersection lines passing through the end point of the weld; the second starting point positioning coordinates and the second end point positioning coordinates of the workpiece to be welded are calculated according to the fourth coordinates, including: calculating the third common perpendicular of the two intersection lines corresponding to the eleventh point set; calculating the second starting point positioning coordinates according to the third common perpendicular and the eleventh point set; calculating the fourth common perpendicular of the two intersection lines corresponding to the twelfth point set; calculating the second end point positioning coordinates according to the fourth common perpendicular and the twelfth point set.

[0124] Reference Figure 3 For example, the third coordinate is used as an example to illustrate: the fourth coordinates corresponding to P1 and P2 constitute an eleventh point set, the fourth coordinates corresponding to P3 and P4 constitute another eleventh point set, the fourth coordinates corresponding to P5 and P6 constitute a twelfth point set, and the fourth coordinates corresponding to P7 and P8 constitute another twelfth point set. P1 and P2 form vector P12, P3 and P4 form vector P34, P5 and P6 form vector P56, and P7 and P8 form vector P78. Due to the errors in robot and human eye teaching, P12 and P34 cannot be completely coplanar (that is, P12 and P34 cannot intersect), and P56 and P78 cannot be coplanar. However, before the welding robot performs the welding operation, the starting point and the end point of the welding must be determined. In this case, if manual teaching is used, multiple points need to be located, which increases the difficulty of teaching. To reduce the difficulty of teaching, this application calculates the midpoint of the common perpendicular line of two non-coplanar straight lines P12 and P34 as the position of the welding start point, and calculates the midpoint of the common perpendicular line of two non-coplanar straight lines P56 and P78 as the position of the welding end point. Furthermore, this method is applicable to the robot coordinate system, reference coordinate system and positioning coordinate system of this application (that is, the steps of calculating the weld start point and weld end point in the robot coordinate system, calculating the weld start point and weld end point in the reference coordinate system, and calculating the weld start point and weld end point in the positioning coordinate system are all the same). To explain this method in detail, the positioning coordinate system is used as an example for explanation below:

[0125] (1)Reference Figure 3 , according to the fourth coordinate of P1 in the positioning coordinate system TF The fourth coordinates of P1 and P2 in the positioning coordinate system TF P2 Construction Vector TF P 12 , according to the fourth coordinate of P3 in the positioning coordinate system TF The fourth coordinate of P3 and P4 in the positioning coordinate system TF P4 build vector TF P34 ;

[0126] (2) Calculate vector TF P 12 and vector TF P 34 The coordinates of the midpoint of the common perpendicular line are used as the second starting point positioning coordinates, wherein the calculation process specifically includes:

[0127] T2=-( TF P 13 * TF P 34 - TF P 12 * TF P 34 * TF P 12 * TF P 13 / ( TF P 12 * TF P 12 )) / ( TF P 12 * TF P 34 * TF P 12 * TF P 34 / ( TF P 12 * TF P 12 )- TF P 34 * TF P 34 )

[0128] T1=-( TF P 12 * TF P 13 + TF P 12 * TF P 34 *T2) / ( TF P 12 * TF P 12 )

[0129] TF P m =T1* TF P 12 + TF P1

[0130] TF P n =T2* TF P34 + TF P3

[0131] TF P start = TF P n +0.5*( TF P m - TF P n )

[0132] in, TF P m and TF P n Both TF P 12 and TF P 34 The intersection of the common perpendicular lines; TF P start is the second starting point location coordinate; T1 is TF P 1m Vector Accounting TF P 12 The proportional coefficient of T2 is TF P 3n Vector Accounting TF P 34 The proportionality coefficient of TF P 13 for TF P1 and TF The vector formed by P3.

[0133] (3) According to the fourth coordinate of P5 in the positioning coordinate system TF The fourth coordinate of P5 and P6 in the positioning coordinate system TF P6 Construction Vector TF P 56 , according to the fourth coordinate of P7 in the positioning coordinate system TF The fourth coordinate of P7 and P8 in the positioning coordinate system TF P8 build vector TF P 78 ;

[0134] (4) Calculate vector TF P 56 and vector TF P 78 The coordinates of the midpoint of the common perpendicular line are used as the second end point positioning coordinates, wherein the calculation process specifically includes:

[0135] T4=-( TF P 57 * TF P 78 - TF P56 * TF P 78 * TF P 56 * TF P 57 / ( TF P 56 * TF P 56 )) / ( TF P 56 * TF P 78 * TF P 56 * TF P 78 / ( TF P 56 * TF P 56 )- TF P 78 * TF P 78 )

[0136] T3=-( TF P 56 * TF P 57 + TF P 56 * TF P 78 *T4) / ( TF P 56 * TF P 56 )

[0137] TF P j =T3* TF P 56 + TF P5

[0138] TF P k =T4* TF P 78 + TF P7

[0139] TF P destination = TF P k +0.5*( TF P j - TF P k )

[0140] in, TF P j and TF Pk Both TF P 56 and TF P 78 The intersection of the common perpendicular lines; TF P destination is the second end point location coordinate; T3 is TF P 5j Vector Accounting TF P 56 The proportional coefficient of T4 is TF P 7k Vector Accounting TF P 78 The proportionality coefficient of TF P 57 for TF P5 and TF The vector formed by P7.

[0141] The method for determining the starting point and end point of the weld in the robot coordinate system and the reference coordinate system (i.e., the calculation method of the starting point machine coordinates, the end point machine coordinates, the starting point reference coordinates, and the end point reference coordinates) is the same as the calculation process for determining the second starting point positioning coordinates and the second end point positioning coordinates in the positioning coordinate system. Both rely on the welding teaching points P1, P2, P3, P4, P5, P6, P7, and P8 for calculation, which will not be repeated here.

[0142] Here, the complete positioning process of this application is described in detail with reference to the specific embodiments. Figure 4 In the figure, D1, D2, and D3 are the welding teaching points of the parts to be welded in the reference coordinate system, and F1, F2, and F3 are the welding teaching points of the parts to be welded in the positioning coordinate system. Here, the coordinates of the welding teaching points in the machine coordinate system are explained: D1 (1, 0, 0); D2 (2, 0, 0); D3 (1, 1, 0); F1 (1, 0, 0), F2 (2, 1, 0),

[0143] Here, the intersection of the perpendicular line from D3 to D1D2 is taken as the origin O of the reference coordinate system {TB}, vector D1D2 = D2-D1 = (1, 0, 0), D1D3 = D3-D1 = (0, 1, 0), vector F1F2 = F2-F1 = (1, 1, 0), Let the unit vector D1D2 / norm(D1D2) of D1D2 be the first axis vector X1, the unit vector (D1D2xD1D3) / norm(D1D2xD1D3) of the cross product of D1D2 and D1D3 be the second axis vector Z1, and the third axis vector Y1 be the cross product of the X1 and Z1 vectors. The intersection of the perpendicular line from D3 to D1D2 is the origin O1(0,0,0) of the reference coordinate system {TB}. The reference coordinate system can be expressed as:

[0144]

[0145] Furthermore, the unit vector F1F2 / norm(F1F2) of F1F2 is taken as the fourth axis vector X2 axis, the unit vector (F1F2xF1F3) / norm(F1F2xF1F3) of the cross product of F1F2 and F1F3 is taken as the fifth axis vector Z2 axis, the sixth axis vector Y2 axis is the cross product of the X2 axis and the Z2 axis vector, and the intersection of the perpendicular line from F3 to F1F2 is taken as the origin O2(0.5,0,0) of the positioning coordinate system {TF}.

[0146] The positioning coordinate system can be expressed as:

[0147]

[0148] Transformation Matrix

[0149] Assume that there is a point Ps in the reference coordinate system, which is the starting point in the robot coordinate system. The coordinates in the robot coordinate system are (1.5, 0, 0). Then the coordinates of the positioning coordinate system corresponding to this point (i.e., the first starting point positioning coordinates) are:

[0150]

[0151]

[0152] It can be understood that the welding operation includes: collecting the current sampling signal of the welding robot during the swing welding process from the calibration starting point positioning coordinates to the calibration end point positioning coordinates according to a preset sampling period; filtering the current sampling signal in the current sampling period to obtain a filtered current signal; integrating the filtered current signal to obtain a sampling current integral; obtaining the swing amplitude of the welding robot in the current sampling period, and obtaining the compensation direction and the compensation value corresponding to the compensation direction based on the sampling current integral of the current sampling period, the sampling current integral of the previous sampling period and the swing amplitude; compensating the welding gun of the welding robot according to the compensation value and the compensation direction.

[0153] It should be noted that, referring to Figure 5 The welding robot will generate a current signal during the weaving welding process. Therefore, the current sampling signal of the welding robot during the weaving welding process can be collected through the Hall sensor, and the current sampling signal in the current sampling period can be filtered to filter out the noise in the current sampling signal and obtain the filtered current signal.

[0154] Furthermore, it is necessary to calculate the integral of the filtered current signal within the current sampling period to obtain the sampling current integral S2, and obtain the sampling current integral S1 of the previous sampling period. Combined with the swing amplitude of the welding robot, the sampling current integral S2 of the current sampling period and the sampling current integral S1 of the previous sampling period, the first compensation direction (left or right), the compensation value level1 corresponding to the first compensation direction, the second compensation direction (up or down) and the compensation value level2 corresponding to the second compensation direction are calculated. Combined with the compensation value level1 corresponding to the first compensation direction and the first compensation direction, the left and right swing directions of the welding robot's welding gun are compensated. Combined with the compensation value level2 corresponding to the second compensation direction and the second compensation direction, the up and down swing directions of the welding robot's welding gun are compensated.

[0155] The filtering operation is described in detail here:

[0156] It can be understood that the current sampling signal in the current sampling period is filtered to obtain a filtered current signal, including: performing median filtering on the current sampling signal in the current sampling period to obtain a median filtered signal; filtering out high-frequency noise in the median filtered signal by a preset cutoff frequency and sampling frequency to obtain a filtered current signal.

[0157] For example, after the Hall sensor collects the current sampling signal during the welding robot's weaving process, it is necessary to perform median filtering on the current sampling signal collected during the current sampling period to remove pulse noise signals caused by factors such as spatter during the welding process, thereby obtaining a median filtered signal. The fourth-order Butterworth filter passband cutoff frequency and sampling frequency are then set; the median filtered signal is processed using a fourth-order Butterworth low-pass filter to remove high-frequency noise from the median filtered signal, thereby obtaining a filtered current signal.

[0158] It can be understood that the compensation direction includes a first compensation direction and a second compensation direction, and the compensation direction and the compensation value corresponding to the compensation direction are obtained according to the sampling current integral of the current sampling period, the sampling current integral of the previous sampling period and the swing amplitude, including: comparing the sampling current integral of the current sampling period with the sampling current integral of the previous sampling period to obtain the sampling period with the larger sampling current integral; obtaining the swing direction of the welding gun end in the sampling period with the larger sampling current integral, when the swing direction of the welding gun end is to the left, the first compensation direction is to the right; when the swing direction of the welding gun end is to the right, the first compensation direction is to the left; for the current sampling period, the first compensation direction is to the right; for the current sampling period, the first compensation direction is to the left. The sampling current integral of the sampling period, the sampling current integral of the previous sampling period, and the swing amplitude are calculated to obtain a compensation value corresponding to the first compensation direction; the sampling current integral of the current sampling period and the sampling current integral of the previous sampling period are calculated to obtain a sampling current integral sum; the preset reference current total value and the sampling current integral sum are compared, when the sampling current integral sum is greater than the reference current total value, the second compensation direction is upward; when the sampling current integral sum is less than the reference current total value, the second compensation direction is downward; the reference current total value and the sampling current integral sum are calculated to obtain a compensation value corresponding to the second compensation direction.

[0159] For example, refer to Figure 5 If the sampling current integral S1 of the previous sampling period is greater than the sampling current integral S2 of the current sampling period, and the swing direction of the welding gun end in the previous sampling period is biased to the left, then the first compensation direction is to the right. Similarly, when the swing direction of the welding gun end in the previous sampling period is biased to the right, then the first compensation direction is to the left.

[0160] Similarly, if the sampling current integral S1 of the previous sampling period is less than the sampling current integral S2 of the current sampling period, and the swing direction of the welding gun end in the current sampling period is biased to the left, then the first compensation direction is to the right. Similarly, when the swing direction of the welding gun end in the current sampling period is biased to the right, then the first compensation direction is to the left.

[0161] Here, it is assumed that the left and right compensation of the weaving welding is a plane, and that the swing direction of the welding gun end in the previous sampling cycle is biased to the left, and the swing direction of the welding gun end in the current sampling cycle is biased to the right. Then, the ratio of the sampling current integral S1 of the previous sampling cycle to the sampling current integral S2 of the current sampling cycle can be approximately converted into the area ratio of the weaving welding track within half a cycle in the plane, that is:

[0162]

[0163]

[0164] Among them, S1 is the integral of the sampled current in the previous sampling period; S2 is the integral of the sampled current in the current sampling period; A is the swing amplitude; level1 is the compensation value corresponding to the first compensation direction; num represents the ratio of the integral of the sampled current in the previous sampling period to the integral of the sampled current in the current sampling period.

[0165] Further, if the sum S1 + S2 of the integral of the sampled current S1 in the previous sampling period and the integral of the sampled current S2 in the current sampling period is greater than the total reference current value S, it indicates that the total current in the current sampling period and the previous sampling period is greater than the total reference current value. At this time, the height of the welding torch is close to the surface of the workpiece (because the shorter the conductor length, the smaller the resistance and the greater the current), then it is determined that the welding torch is too low at this time and the welding torch needs to be raised, and the current second compensation direction is upward. Similarly, if the sum S1 + S2 of the integral of the sampled current S1 in the previous sampling period and the integral of the sampled current S2 in the current sampling period is less than the total reference current value S, it indicates that the total current in the current sampling period and the previous sampling period is less than the total reference current value. At this time, the height of the welding torch is far from the surface of the workpiece (because the longer the conductor length, the greater the resistance and the smaller the current), then it is determined that the welding torch is too high at this time and the welding torch needs to be lowered, and the current second compensation direction is downward.

[0166] If the difference between the sum S1 + S2 of the integral of the sampled current S1 in the previous sampling period and the integral of the sampled current S2 in the current sampling period and the total reference current value S is greater, the compensation level is higher. Here, the compensation value corresponding to the second compensation direction is described:

[0167]

[0168] Among them, S1 is the integral of the sampled current in the previous sampling period; S2 is the integral of the sampled current in the current sampling period; S is the preset total reference current value; level2 is the compensation value corresponding to the second compensation direction.

[0169] In a second aspect, referring to Figure 6 , an automatic positioning welding system provided by an embodiment of the present application includes:

[0170] At least one memory 200;

[0171] At least one processor 100;

[0172] At least one program;

[0173] The program is stored in the memory 200, and the processor 100 executes at least one program to implement:

[0174] The automatic positioning welding method according to any one of the embodiments of the first aspect of the present application.

[0175] The processor 100 and the memory 200 may be connected via a bus or other means.

[0176] The memory 200 is a non-transitory readable storage medium that can be used to store non-transitory software instructions and non-transitory instructions. In addition, the memory 200 may include a high-speed random access memory 200, and may also include a non-transitory memory 200, such as at least one disk storage device 200, a flash memory device, or other non-transitory solid-state storage device 200. It is understood that the memory 200 optionally includes a memory 200 remotely located relative to the processor 100, and these remote memories 200 can be connected to the processor 100 via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0177] The processor 100 executes non-transient software instructions, commands and signals stored in the memory 200, thereby performing various functional applications and data processing, thereby realizing the automatic positioning welding method of the first embodiment described above.

[0178] The non-transient software instructions and instructions required to implement the automatic positioning welding method of the above embodiment are stored in the memory 200. When executed by the processor 100, the automatic positioning welding method of the first embodiment of the present application is executed, for example, the above-described Figure 1 Method steps S110 to S180 in .

[0179] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer-executable signal, and the computer-executable signal is used to execute:

[0180] An automatic positioning welding method as described in any embodiment of the first aspect of the application.

[0181] For example, executing the above description Figure 1 Method steps S110 to S180 in .

[0182] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected based on actual needs to achieve the objectives of this embodiment.

[0183] By the description of the above embodiments, it will be appreciated by those skilled in the art that all or some of the steps and systems in the method disclosed above can be implemented as software, firmware, hardware and appropriate combinations thereof. Some physical components or all physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a readable medium, and the readable medium can include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term computer storage medium is included in any method or technology for storing information (such as a computer-readable signal, a data structure, an instruction module or other data) and is volatile and non-volatile, removable and non-removable. Computer storage media includes but is not limited to RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassette, magnetic tape, disk storage or other magnetic storage device, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, as is well known to those skilled in the art, communication media typically embodies computer-readable signals, data structures, instruction modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0184] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the purpose of the present application.

Claims

1. An automatic positioning welding method, applied to a welding robot, characterized in that: include: Before performing the spot welding operation, obtaining first coordinates of a plurality of welding teaching points of the workpiece to be welded in the robot coordinate system; Establishing a reference coordinate system based on the first coordinates, and obtaining second coordinates corresponding to each of the first coordinates in the reference coordinate system; calculating the starting point reference coordinates and the ending point reference coordinates of the workpiece to be welded based on the second coordinates; After performing the spot welding operation, reacquiring the third coordinates of the plurality of welding teaching points corresponding one to one in the robot coordinate system; establishing a positioning coordinate system based on the third coordinates, and obtaining the fourth coordinates of each of the third coordinates corresponding one to one in the positioning coordinate system; Calculating a transformation matrix between the reference coordinate system and the positioning coordinate system according to the fourth coordinate and the second coordinate; Calculating the first starting point positioning coordinates and the first ending point positioning coordinates in the positioning coordinate system according to the conversion matrix, the starting point reference coordinates and the ending point reference coordinates; Calculate the second starting point positioning coordinates and the second end point positioning coordinates of the workpiece to be welded according to the fourth coordinates; Calculating the calibration starting point positioning coordinates according to the first starting point positioning coordinates and the second starting point positioning coordinates; Calculating the calibration endpoint positioning coordinates according to the first endpoint positioning coordinates and the second endpoint positioning coordinates; Performing a welding operation on the workpiece weld according to the calibration starting point positioning coordinates and the calibration end point positioning coordinates; The first coordinates include two first point sets; the two first point sets correspond one-to-one to coordinate sets of at least two welding teaching points on two intersection lines passing through the weld start point or the weld end point; and establishing a reference coordinate system based on the first coordinates includes: Constructing a first teaching straight line on any side of the workpiece to be welded, wherein the first teaching straight line is parallel to a vector from the welding start point to the welding end point; Select multiple points on the first teaching line to obtain a third point set; Constructing a second teaching line parallel to the first teaching line on any side of the workpiece to be welded, and selecting a plurality of points on the second teaching line to obtain a fourth point set; Determine a third coordinate axis point based on the fourth point set, obtain a first perpendicular line that is perpendicular to the first teaching straight line and passes through the third coordinate axis point, and use the intersection of the first perpendicular line and the first teaching straight line as the origin of the reference coordinate system; determining a first axis vector of the reference coordinate system according to one of the first point sets; determining a second axis vector perpendicular to the first axis vector in the reference coordinate system according to another first point set and the first axis vector; determining a third axis vector from the first axis vector and the second axis vector; The reference coordinate system is obtained according to the origin of the reference coordinate system, the first axis vector, the second axis vector, and the third axis vector.

2. The automatic positioning welding method according to claim 1, characterized in that: The third coordinates include two fifth point sets; the two fifth point sets correspond one-to-one to coordinate sets of at least two welding teaching points on two intersection lines passing through the weld start point or the weld end point; and establishing a positioning coordinate system based on the third coordinates includes: Constructing a third teaching straight line on any side of the workpiece to be welded, wherein the third teaching straight line is parallel to a vector from the welding start point to the welding end point; Selecting multiple points on the third teaching straight line to obtain a seventh point set; Constructing a fourth teaching line parallel to the third teaching line on any side of the workpiece to be welded, and selecting a plurality of points on the fourth teaching line to obtain an eighth point set; Determine a fourth coordinate axis point based on the eighth point set, obtain a second perpendicular line that is perpendicular to the third teaching straight line and passes through the fourth coordinate axis point, and use the intersection of the second perpendicular line and the third teaching straight line as the origin of the positioning coordinate system; Determine a fourth axis vector of the positioning coordinate system according to one of the fifth point sets; determining a fifth axis vector perpendicular to the fourth axis vector in the positioning coordinate system according to another fifth point set and the fourth axis vector; determining a sixth axis vector from the fourth axis vector and the fifth axis vector; The positioning coordinate system is obtained according to the origin of the positioning coordinate system, the fourth axis vector, the fifth axis vector and the sixth axis vector.

3. The automatic positioning welding method according to claim 1, characterized in that: The step of calculating the calibration starting point positioning coordinates according to the first starting point positioning coordinates and the second starting point positioning coordinates includes: Calculating an average of the first starting point positioning coordinates and the second starting point positioning coordinates to obtain the calibration starting point positioning coordinates; The step of calculating the calibration endpoint positioning coordinates according to the first endpoint positioning coordinates and the second endpoint positioning coordinates includes: An average value of the first end point positioning coordinate and the second end point positioning coordinate is calculated to obtain the calibration end point positioning coordinate.

4. The automatic positioning welding method according to claim 1, characterized in that: The second coordinates include two ninth point sets and two tenth point sets; the two ninth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on two intersection lines passing through the starting point of the weld; the two tenth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on two intersection lines passing through the end point of the weld; the starting point reference coordinates and the end point reference coordinates of the workpiece to be welded are calculated based on the second coordinates, including: Calculate the first common perpendicular line of the two intersection lines corresponding to the ninth point set; Calculate the starting point reference coordinates based on the first common perpendicular line and the ninth point set; Calculate the second common perpendicular line of the two intersection lines corresponding to the tenth point set; Calculate the end point reference coordinates based on the second common perpendicular line and the tenth point set; The fourth coordinates include two eleventh point sets and two twelfth point sets; the two eleventh point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on the two intersection lines passing through the weld start point; the two twelfth point sets correspond one-to-one to the coordinate sets of at least two welding teaching points on the two intersection lines passing through the weld end point; the second starting point positioning coordinates and the second end point positioning coordinates of the workpiece to be welded are calculated based on the fourth coordinates, including: Calculate the third common perpendicular line of the two intersection lines corresponding to the eleventh point set; Calculating the second starting point positioning coordinates based on the third common perpendicular line and the eleventh point set; Calculate the fourth common perpendicular line of the two intersection lines corresponding to the twelfth point set; The second end point positioning coordinates are calculated based on the fourth common perpendicular and the twelfth point set.

5. The automatic positioning welding method according to claim 1, characterized in that: The welding operation includes: Collecting the current sampling signal of the welding robot during the weaving welding process from the calibration starting point positioning coordinate to the calibration end point positioning coordinate according to a preset sampling period; Performing a filtering operation on the current sampling signal in the current sampling period to obtain a filtered current signal; Integrate the filtered current signal to obtain the sampled current integral; Obtaining the swing amplitude of the welding robot in the current sampling period, and obtaining a compensation direction and a compensation value corresponding to the compensation direction according to the sampling current integral of the current sampling period, the sampling current integral of the previous sampling period, and the swing amplitude; The welding gun of the welding robot is compensated according to the compensation value and the compensation direction.

6. The automatic positioning welding method according to claim 5, characterized in that: The filtering operation is performed on the current sampling signal in the current sampling period to obtain a filtered current signal, including: Performing median filtering on the current sampling signal in the current sampling period to obtain a median filtered signal; The high-frequency noise in the median filter signal is filtered out by using a preset cutoff frequency and sampling frequency to obtain the filtered current signal.

7. The automatic positioning welding method according to claim 5, characterized in that: The compensation direction includes a first compensation direction and a second compensation direction, and obtaining the compensation direction and the compensation value corresponding to the compensation direction according to the sampling current integral of the current sampling period, the sampling current integral of the previous sampling period, and the swing amplitude includes: Compare the sampling current integral of the current sampling period with the sampling current integral of the previous sampling period to obtain the sampling period with the larger sampling current integral; Obtaining the swing direction of the welding gun end during the sampling period in which the sampling current integral is larger, when the swing direction of the welding gun end is left, the first compensation direction is right; when the swing direction of the welding gun end is right, the first compensation direction is left; Calculating the sampling current integral of the current sampling period, the sampling current integral of the previous sampling period, and the swing amplitude to obtain a compensation value corresponding to the first compensation direction; Calculate the sum of the sampling current integral of the current sampling period and the sampling current integral of the previous sampling period to obtain the sampling current integral sum; comparing a preset reference current total value with the integrated sum of the sampled currents; when the integrated sum of the sampled currents is greater than the reference current total value, the second compensation direction is upward; and when the integrated sum of the sampled currents is less than the reference current total value, the second compensation direction is downward; The total value of the reference current and the integral sum of the sampled current are calculated to obtain a compensation value corresponding to the second compensation direction.

8. An automatic positioning welding system, characterized in that: include: at least one processor; at least one program; The programs are stored in the memory, and the processor executes at least one of the programs to implement: The automatic positioning welding method according to any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer-executable signal, wherein the computer-executable signal is used to execute: The automatic positioning welding method according to any one of claims 1 to 7.

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