A method of teaching-free welding of a rivet-type pipe clamp, medium and apparatus

Abstract

The application provides a rivet type pipe clamp teaching-free welding method, medium and equipment, which comprises the following steps: obtaining a pipe clamp workpiece point cloud, determining a pipe clamp workpiece plane equation according to the pipe clamp workpiece point cloud, segmenting a welding seam plane area point cloud and a rivet parameter area point cloud, dividing the welding seam plane area point cloud and the rivet parameter area point cloud to obtain a plurality of welding seam plane sub-area point clouds and rivet parameter sub-area point clouds, determining a circular equation according to the rivet parameter sub-area point cloud, determining a welding seam plane equation according to the welding seam plane area point cloud, and projecting the circular equation to the welding seam plane equation to obtain a rivet circular welding seam, so that the problems of high use cost, low efficiency and unstable production process quality of the existing welding method when welding non-standard or special-shaped workpieces are solved.

Description

Technical Field

[0001] This invention relates to the field of automated welding technology, and in particular to a teach-free welding method, medium, and equipment for riveted pipe clamps. Background Technology

[0002] Riveted pipe clamps are important fasteners that use rivets to secure pipes, and are widely used in the connection and installation of various metal or plastic pipes. In the manufacturing and use of riveted pipe clamps, welding is generally used to fix the connection between the rivet and the clamp. Given that this welding operation must meet stringent requirements of high strength, high precision, and high stability, the welding technology for riveted pipe clamps is extremely demanding.

[0003] Currently, the two most common welding techniques for riveted pipe clamp welding are robotic teaching welding and manual welding. While both robotic teaching welding and manual welding have their advantages, they also have some drawbacks. For robotic teaching welding, although it can perform riveted pipe clamp welding on most standardized workpieces, its adaptability is poor when dealing with non-standardized or irregularly shaped workpieces, requiring the resetting of paths and parameters, which is time-consuming and labor-intensive. Furthermore, teaching welding lacks the ability to perceive and respond to external information, and cannot adjust the welding state in real time, thus making it prone to deviations or errors.

[0004] Therefore, existing welding methods still suffer from high costs and low efficiency when welding non-standard or irregularly shaped workpieces, as well as unstable quality during the manufacturing process. Summary of the Invention

[0005] Based on this, the purpose of this application is to provide a teachless welding method, medium, and equipment for riveted pipe clamps to solve at least one of the technical problems mentioned in the background art.

[0006] In a first aspect, this application provides a teach-free welding method for riveted pipe clamps, comprising:

[0007] S1: Obtain the point cloud of the pipe clamp workpiece;

[0008] S2: Based on the point cloud of the pipe clamp workpiece, determine the plane equation of the pipe clamp workpiece, and divide the point cloud of the weld plane region and the point cloud of the rivet parameter region;

[0009] S3: Divide the weld plane region point cloud and the rivet parameter region point cloud to obtain several weld plane sub-region point clouds and rivet parameter sub-region point clouds;

[0010] S4: Determine the circular equation based on the point cloud of the rivet parameter sub-region;

[0011] S5: Based on the point cloud of the weld plane region, determine the weld plane equation, and project the circular equation onto the weld plane equation to obtain the rivet circular weld.

[0012] Furthermore, the specific steps of step S1 include:

[0013] Obtain the initial workpiece point cloud;

[0014] The initial workpiece point cloud is filtered to obtain the filtered workpiece point cloud.

[0015] A preset threshold is used to segment and filter the workpiece point cloud, resulting in the pipe clamp workpiece point cloud.

[0016] Furthermore, the specific steps of step S2 include:

[0017] S21: Set up a planar model, randomly select n points from the point cloud of the pipe clamp workpiece, fit and determine the parameters of the planar model, and obtain the current planar equation;

[0018] S22: Determine the updated internal points based on the distance between each point in the point cloud of the pipe clamp workpiece and the current plane equation, and count the number of updated internal points;

[0019] S23: Determine whether the number of updated internal points is greater than the quantity threshold. If it is less, return to step S21; if it is not less, the final plane equation is obtained.

[0020] S24: Calculate the perpendicular distance from each point in the pipe clamp workpiece point cloud to the final plane equation, and determine whether the distance is greater than the set threshold. If it is less than the threshold, it is considered as the weld plane region point cloud; if it is not less than the threshold, it is considered as the rivet parameter region point cloud.

[0021] Furthermore, the specific steps of step S3 include:

[0022] Clustering of the point cloud of the weld plane region based on the distance to adjacent points yields several weld plane sub-region point clouds;

[0023] The range of the point cloud of the weld plane sub-region is obtained, and the point cloud of the rivet parameter region is filtered according to the range to obtain several point clouds of the rivet parameter sub-region.

[0024] Furthermore, the specific steps of step S31 include:

[0025] S311: Calculate the distances between all points in the point cloud of the weld plane region and their adjacent points;

[0026] S312: Randomly select a point in the point cloud and divide the point cloud into a weld plane sub-region where the distance between the point cloud and its neighboring points is less than a preset distance coefficient threshold.

[0027] S313: Remove the point cloud of the weld plane sub-region and return to step S312 until all points of the weld plane region point cloud are divided into several weld plane sub-region point clouds.

[0028] Furthermore, the specific steps of step S4 include:

[0029] Calculate the point cloud boundary of the point cloud for each rivet parameter sub-region to obtain the boundary point cloud;

[0030] Determine the equation of the circle based on the boundary point cloud.

[0031] Further, the specific steps to obtain the boundary point cloud include:

[0032] Obtain the normal direction of each point cloud and divide the point cloud into several spheres;

[0033] Obtain the average normal direction of the point cloud in each sphere, and determine whether the angle between the normal direction of the point and the corresponding average normal direction is less than a preset threshold. If it is not less than the threshold, it is a boundary point cloud.

[0034] Furthermore, the specific steps for determining the equation of a circle include:

[0035] S421: Set up a circular model, and randomly select several points from the boundary point cloud as the current interior points. Fit the parameters of the circular model to obtain the current circular equation.

[0036] S422: Based on the distance between each point in the boundary point cloud and the current circular equation, determine the updated interior points and count the number of updated interior points;

[0037] S423: Determine whether the number of updated inner points is greater than the quantity threshold. If it is less than the threshold, return to step S421; if it is not less than the threshold, the final circular equation is obtained.

[0038] Furthermore, the specific steps of step S5 include:

[0039] The plane equation of the weld is determined based on the point cloud of the weld plane region;

[0040] Projecting the circular equation onto the weld plane equation yields the circular weld of the rivet.

[0041] Furthermore, the method also includes:

[0042] Construct a straight line model based on the center of the circular weld of each rivet;

[0043] Determine if the distance between each circle center and the straight line model is greater than a set threshold. If it is, remove the rivet circular weld corresponding to the circle center; otherwise, leave it unchanged.

[0044] Determine whether the distance between any two center points of the remaining welds is within a set distance threshold range. If it is less than the threshold, remove two welds; if it is greater than the threshold, there is a problem of missed identification, and the final weld result is obtained.

[0045] Secondly, this application also provides a computer storage medium storing executable program code; the executable program code is used to execute the teachless welding method for riveted pipe clamps as described in any one of the first aspects.

[0046] Thirdly, this application also provides a terminal device, including a memory and a processor; the memory stores program code executable by the processor; the program code is used to execute the teachless welding method for riveted pipe clamps as described in any one of the first aspects.

[0047] The aforementioned no-teachability welding method, medium, and equipment for riveted pipe clamps obtains several sub-regional point clouds of the weld plane and rivet parameters from the point cloud of the pipe clamp workpiece. Based on the rivet parameter sub-regional point clouds, a circular equation is determined, and this circular equation is projected onto the weld plane to obtain a circular weld for the rivet. This solves the problems of high cost, low efficiency, and unstable quality in existing welding methods when welding non-standard or irregularly shaped workpieces. Attached Figure Description

[0048] Figure 1 This is a flowchart of a teach-free welding method for a rivet-type pipe clamp according to an embodiment of the present invention;

[0049] Figure 2 This is a schematic diagram showing the relative positions of the weld plane region and the rivet parameter region in an embodiment of the present invention;

[0050] Figure 3 This is an example diagram of the weld point distribution according to an embodiment of the present invention. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] It should be noted that if the embodiments of the present invention involve directional indications, such as up, down, left, right, front, back, etc., these directional indications are only used to explain the relative positional relationships and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. Furthermore, if the embodiments of the present invention involve descriptions such as "first," "second," "S1," "S2," "step one," "step two," etc., these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance, or implicitly indicating the number of technical features indicated or the order of method execution. Those skilled in the art will understand that anything that does not violate the inventive concept and is within the scope of the present invention should be included in the protection scope of the present invention.

[0053] like Figure 1 As shown, the present invention provides a teach-free welding method for riveted pipe clamps, the method comprising:

[0054] Step S1: Obtain the point cloud of the pipe clamp workpiece;

[0055] Specifically, it is optional, but not limited to, acquiring images of the workpiece being gripped by the pipe clamp using a data acquisition device to obtain point cloud data of both the pipe clamp and the workpiece, thus obtaining the point cloud of the pipe clamp and the workpiece.

[0056] More specifically, the acquisition device may be, but is not limited to, electronic devices such as cameras, optical scanners, smartphones, or tablets that can be used to capture still images or continuous video.

[0057] Preferred, optional, but not limited to:

[0058] S11: Obtain the initial workpiece point cloud;

[0059] S12: Filter the initial workpiece point cloud to obtain the filtered workpiece point cloud;

[0060] S13: Set a preset threshold to segment and filter the workpiece point cloud to obtain the pipe clamp workpiece point cloud.

[0061] Specifically, after acquiring the workpiece point cloud, the workpiece point cloud is filtered using a pass-through filtering and uniform downsampling method. Then, a region growing segmentation algorithm is used to segment the workpiece point cloud based on a preset smoothness threshold Th. smooth and curvature threshold Th curvature The point cloud of the pipe clamp workpiece is obtained by segmenting and filtering the other point clouds of the workpiece point cloud and the pipe clamp workpiece point cloud.

[0062] Step S2: Based on the point cloud of the pipe clamp workpiece, determine the plane equation of the pipe clamp workpiece, and divide the point cloud of the weld plane region and the point cloud of the rivet parameter region;

[0063] Specifically, the equations that the workpiece must satisfy can be determined based on planar features, but are not limited to this step. The point cloud of the pipe clamp workpiece is then substituted into the equations to filter out points that satisfy them. The equation coefficients are calculated based on these points to obtain the final planar equation of the pipe clamp workpiece.

[0064] S21: Set up a planar model, randomly select n points from the point cloud of the pipe clamp workpiece, fit and determine the parameters of the planar model, and obtain the current planar equation;

[0065] Specifically, the planar model can be optionally defined based on the plane's characteristics and the equations it needs to satisfy. For example, the planar model can be defined using the plane's normal vector and a constant term as parameters; more specifically, the parameters of this planar model can be optionally defined as (A, B, C, D), where A, B, and C are the components of the plane's normal vector, and D is the constant term of the plane's equation, which can be expressed as Ax + By + Cz + D = 0.

[0066] It is worth noting that the equations and parameters required for this planar model are for illustrative purposes only and are not intended to be limiting.

[0067] More specifically, optionally but not limited to, three points P1(x1,y1,z1), P2(x2,y2,z2), and P3(x3,y3,z3) are randomly selected from the point cloud of the pipe clamp workpiece as the current interior points. These points are then substituted into the plane equation to fit and calculate the parameters of the plane model. The formula for calculating the plane normal vector is: × represents the cross product operation, which substitutes the normal vector and any point into the plane equation to obtain the coefficients of the current plane equation.

[0068] S22: Determine the updated internal points based on the distance between each point in the point cloud of the pipe clamp workpiece and the current plane equation, and count the number of updated internal points;

[0069] Specifically, the method may, but is not limited to, using existing distance calculation formulas to calculate the distance from each point in the point cloud of the pipe clamp workpiece to the current plane equation, and determine whether the distance is greater than a preset threshold. If the value is not greater than the specified value, then the point is counted as an interior point of the planar model, and the number of interior points is updated accordingly.

[0070] For example, assuming the point cloud of the pipe clamp workpiece includes 100 points, it is calculated that the distance from 40 points to the plane equation is not greater than a preset threshold. These 40 points are the updated internal points, and the number of updated internal points is recorded as 40.

[0071] S23: Determine whether the number of updated internal points is greater than the quantity threshold. If it is less, return to step S21; if it is not less, the final plane equation is obtained.

[0072] Specifically, if the updated number of interior points is not less than the quantity threshold, it means that these interior points are sufficient to calculate the accurate parameters of the plane equation, and the fitted plane equation is confirmed as the final accurate plane equation. If it is less than the quantity threshold, return to step S21.

[0073] For example, assuming there are 100 points in the point cloud of the pipe clamp workpiece, calculate the distance from each of these 100 points to the current plane equation, where the distance in the point cloud is no greater than a threshold. There are 30 points in total. These 30 points are counted as the updated internal point count, and the preset internal point count threshold is used. If the number of inner points is less than the threshold, return to step S21, randomly select 3 points from the point cloud again, fit and calculate the parameters of the planar model, and then iteratively update the number of inner points according to step S22 until the number of inner points is not less than the threshold.

[0074] More specifically, suppose that after multiple iterations, the number of interior points consistently fails to meet the preset threshold. However, in order to improve computational efficiency and avoid iterating indefinitely, it is possible, but not limited to, setting a pre-defined iteration termination condition, such as ending the iteration process early when the maximum number of iterations t is reached.

[0075] Preferably, after step S23, the method further includes:

[0076] S24: Calculate the perpendicular distance from each point in the pipe clamp workpiece point cloud to the final plane equation, and determine whether the distance is greater than the set threshold. If it is less than the threshold, it is considered as the weld plane region point cloud; if it is not less than the threshold, it is considered as the rivet parameter region point cloud.

[0077] Specifically, after the iteration, the perpendicular distance from each point in the pipe clamp workpiece point cloud to the final plane equation is calculated. Based on a set threshold, the pipe clamp workpiece point cloud is divided into point clouds representing the weld plane region and point clouds representing the rivet parameter region. The weld plane region and the rivet parameter region are as follows: Figure 2 As shown, the bottom rectangular area is the weld plane area, and the top rectangular area is the rivet parameter area.

[0078] For example, a threshold T1 is set, and the vertical distance from each point in the pipe clamp workpiece point cloud to the plane equation of the pipe clamp workpiece is calculated. It is then determined whether the distance is greater than the set threshold T1. Points with a distance less than the set threshold are regarded as the weld plane region point cloud, and points with a distance greater than the set threshold are regarded as the rivet parameter region point cloud. This allows the pipe clamp workpiece point cloud to be divided into the weld plane region point cloud and the rivet parameter region point cloud.

[0079] Step S3: Divide the weld plane region point cloud and the rivet parameter region point cloud to obtain several weld plane sub-region point clouds and rivet parameter sub-region point clouds;

[0080] S31: Cluster the point cloud of the weld plane region according to the distance to the adjacent points to obtain several weld plane sub-region point clouds;

[0081] S311: Calculate the distances between all points in the point cloud of the weld plane region and their adjacent points;

[0082] Specifically, it is optional, but not limited to, defining adjacent points as points that are adjacent to each other in the topology. For example, the point cloud can be viewed as an undirected graph, where each point represents a node and each line segment connecting two adjacent points represents an edge. Then, depth-first search or breadth-first search can be used to find the adjacent points of each point and calculate the distance between each point and its adjacent points.

[0083] Preferably, for each point in the point cloud of the weld plane region, the distance between it and all other points is calculated, and the k points closest to that point are selected as its neighbors; k is a specific number set by those skilled in the art.

[0084] S312: Randomly select a point in the point cloud and divide the point cloud into a weld plane sub-region where the distance between the point cloud and its neighboring points is less than a preset distance coefficient threshold.

[0085] Specifically, a distance coefficient threshold d is set, and points whose distance to neighboring points is less than d are divided into a cluster to obtain a point cloud of a weld plane sub-region.

[0086] For example, if the weld plane region includes 50 points, randomly select one point from the point cloud, and divide all points that are directly or indirectly connected to it and whose distance from the adjacent points is less than d into a cluster to form a weld plane sub-region point cloud.

[0087] Preferably, after step S312, the method further includes:

[0088] S313: Remove the point cloud of the weld plane sub-region and return to step S312 until all points of the weld plane region point cloud are divided into several weld plane sub-region point clouds.

[0089] Specifically, the weld plane sub-region point cloud obtained in step S312 is removed from the weld plane region point cloud. The remaining point cloud in the weld plane region point cloud is further divided according to step S312 until all points are respectively divided into a certain weld plane sub-region, resulting in m weld plane sub-region point clouds.

[0090] S32: Obtain the range of the point cloud of the weld plane sub-region, and filter the point cloud of the rivet parameter region according to the range to obtain several point clouds of the rivet parameter sub-region.

[0091] Specifically, the range of the point cloud of the m weld plane sub-regions obtained in calculation step S313 is represented as (x i min ,y i min ,z i min ) and (x i max ,y i max ,z i max ), where i = 1, 2, ..., m, x i min and x i max Represents the minimum and maximum values ​​of the point cloud of the i-th weld plane sub-region on the x-axis, y i min and yi max Let z represent the minimum and maximum values ​​of the point cloud of the i-th weld plane sub-region on the y-axis. i min and z i max This represents the minimum and maximum values ​​of the point cloud of the i-th weld plane sub-region on the z-axis, and gives the range of the point clouds of the m weld plane sub-regions on the x and y axes (x...). i min ,y i min ) and (x i max ,y i max Based on the range of the point cloud of each weld plane sub-region, the rivet parameter region point cloud is subjected to pass-through filtering to obtain m rivet parameter region point clouds corresponding to m weld plane sub-region point clouds.

[0092] Step S4: Determine the circular equation based on the point cloud of the rivet parameter sub-region;

[0093] S41: Calculate the point cloud boundary of the point cloud for each rivet parameter sub-region to obtain the boundary point cloud;

[0094] S411: Obtain the normal direction of each point cloud and divide the point cloud into several spheres;

[0095] Specifically, the normal direction of each point cloud is calculated based on the point cloud normal estimation method, and a distance r is set. boundary In the point cloud of the rivet parameter sub-region, at intervals of 2*r boundary Set a center point of the sphere, with r boundaryThe point cloud of the rivet parameter sub-region is divided into several spheres with a radius, and the point cloud outside the sphere region is removed; point cloud normal estimation methods include common normal direction calculation methods such as least squares method, KD tree method, mesh method, and normal integration method; distance r boundary The parameters can be arbitrarily set by those skilled in the art based on the distribution of points in the point cloud of the rivet parameter sub-region.

[0096] Preferably, after dividing the point cloud of the rivet parameter sub-region into several spheres, the point cloud of the sphere region is removed, with r boundary Divide the point cloud that is not in the spherical region into several spheres with a radius. Repeat the process of removing point clouds in the spherical region and dividing the remaining point clouds until all point clouds are divided. Set a threshold for the number of point clouds and remove spheres with a number of point clouds less than the threshold, keeping the remaining spheres.

[0097] S412: Obtain the average normal direction of the point cloud in each sphere, and determine whether the angle between the normal direction of the point and the corresponding average normal direction is less than a preset threshold. If it is not less than the threshold, it is a boundary point cloud.

[0098] Specifically, based on the spheres obtained in step S411, the average value of the normal directions of all point clouds corresponding to each sphere is calculated to obtain the average normal direction of each sphere's point cloud. An angle threshold θ is set, and the angle between the normal direction of each point cloud and the average normal direction of the corresponding sphere's point cloud is compared. If the angle is greater than θ, the point cloud is confirmed as a boundary point cloud.

[0099] S42: Determine the equation of the circle based on the boundary point cloud.

[0100] S421: Set up a circular model, and randomly select several points from the boundary point cloud as the current interior points. Fit the parameters of the circular model to obtain the current circular equation.

[0101] Specifically, a circular model can be optionally, but is not limited to, defined based on circular features and the equations it needs to satisfy. For example, a circular model is created, whose parameters can be optionally, but are not limited to, defined as (x, y, z, a, b, c, r), where (x, y, z) are the coordinates of the circle's center, (a, b, c) are the direction vectors of the circular equation, and r is the circle's radius. Then, several points are randomly selected from the boundary point cloud and substituted into the circular model to obtain the equation coefficients of the current circular equation. It is worth noting that the equations and parameters required for this circular model are for illustrative purposes only and are not intended to be limiting.

[0102] More specifically, optionally but not limited to, randomly selecting three points P1, P2, P3 from the boundary point cloud as the current interior points, substituting them into the circular equation, and fitting and calculating the parameters of the circular model, where the formula for calculating the center of the circle is... The formula for calculating the radius is: The formula for calculating the plane normal vector is: × represents the cross product operation, which yields the current circular equation.

[0103] S422: Based on the distance between each point in the boundary point cloud and the current circular equation, determine the updated interior points and count the number of updated interior points;

[0104] Specifically, the distance between each point in the boundary point cloud and the current circular equation is calculated, and a distance threshold is set. Determine if the distance is less than If the value is less than 1, then the point is counted as an interior point of the circular model, and the number of interior points is updated.

[0105] For example, assuming the boundary point cloud includes 50 points, if the distance from 30 points to the circular equation is no greater than a preset threshold, and the distance from 20 points to the circular equation is greater than the preset threshold, then the 30 points whose distance is no greater than the preset threshold are the updated inner points, and the number of updated inner points is recorded as 30.

[0106] S423: Determine whether the number of updated inner points is greater than the quantity threshold. If it is less than the threshold, return to step S421; if it is not less than the threshold, the final circular equation is obtained.

[0107] Specifically, if the number of internal points is updated, it should not be less than the quantity threshold. This indicates that these interior points are sufficient to calculate the accurate parameters of the circular equation, and the fitted circular equation is confirmed as the final accurate circular equation. If the number is less than the threshold... Then return to step S21.

[0108] Example, quantity threshold The value was set to 40, but the calculated updated internal points were 30, which is less than 40. Then return to step S421, randomly select 3 points from the boundary point cloud again, fit and calculate the parameters of the circular model, and then iteratively update the number of inner points according to step S422 until the number of inner points is not less than the quantity threshold.

[0109] More specifically, suppose that after multiple iterations, the number of interior points consistently fails to meet the preset threshold. However, in order to improve computational efficiency and avoid iterating indefinitely, it is possible, but not limited to, setting a pre-defined iteration termination condition, such as ending the iteration process early when the preset maximum number of iterations is reached.

[0110] Step S5: Determine the plane equation of the weld seam based on the point cloud of the weld seam plane region, and project the circular equation onto the plane equation of the weld seam to obtain the circular weld seam of the rivet;

[0111] S51: Determine the plane equation of the weld based on the point cloud of the weld plane region;

[0112] Specifically, the weld plane model can be optionally, but is not limited to, based on the plane characteristics and the equations it needs to satisfy. For example, the weld plane model is set using the plane normal vector and a constant term as parameters; more specifically, the parameters of this weld plane model can be optionally, but are not limited to, defined as: (A, B, C, D), where A, B, and C are the components of the normal vector of the weld plane, and D is the constant term of the weld plane equation. The weld plane equation can be optionally, but is not limited to, expressed as: Ax + By + Cz + D = 0. It is worth noting that the equations and parameters that this weld plane model needs to satisfy are for illustrative purposes only and are not intended to be limiting.

[0113] Specifically, it is optional, but not limited to, randomly selecting 3 points P from the point cloud of the weld plane region. a ,P b ,P c Let be the current interior point. Substitute this point into the plane equation and calculate the parameters of the weld plane model using the fitting method. The formula for calculating the plane normal vector is: × represents the cross product operation, which substitutes the normal vector and any point into the plane equation Ax+By+Cz+D=0 to obtain the equation coefficients of the current weld plane equation.

[0114] Preferably, after step S51, the method further includes:

[0115] S52: Project the circular equation onto the weld plane equation to obtain the rivet circular weld.

[0116] For example, based on the parameters of the circle equation obtained in step S4, the center coordinates (x... i ,y i ,z i Projecting along the direction vector (a,b,c) onto the weld plane equation, where i=1,2,...,m, yields the coordinates of the center (x,b,c) of the circular weld seam of the rivet. i ',y i ',z i The radius and direction vector of the circular weld seam of the rivet are consistent with the circular equation before projection, so that m weld seams S={s1,s2,..,s m}

[0117] This embodiment presents a teach-free welding method for rivet-type pipe clamps according to the present invention. By segmenting the weld plane region point cloud and the rivet parameter region point cloud in the point cloud of the pipe clamp workpiece, several weld plane sub-region point clouds and rivet parameter sub-region point clouds are obtained. Based on the rivet parameter sub-region point clouds, a circular equation is determined, and the circular equation is projected onto the weld plane to obtain a circular weld for the rivet. This solves the problems of high cost, low efficiency, and unstable quality in existing welding methods when welding non-standard or irregularly shaped workpieces.

[0118] More preferably, the teach-free welding method for riveted pipe clamps of the present invention further includes:

[0119] Step S6: Perform anomaly inspection and screening on the weld to obtain the final weld result.

[0120] Specifically, since there will be certain errors in each step of the actual operation, resulting in misidentification or omission, it is necessary to inspect and screen the obtained welds, find the missed welds and remove the misidentified abnormal welds, so as to obtain the final accurate weld results and avoid problems during the final welding process, thereby reducing efficiency.

[0121] Preferably, step S6 may include, but is not limited to:

[0122] S61: Construct a straight line model based on the center of the circular weld of each rivet;

[0123] Specifically, by Figure 3 As shown, the centers of each weld are distributed along a straight line. A linear model y = mx + b can be constructed by fitting the center points of the welds using linear fitting methods such as least squares, RANSAC, and Principal Component Analysis (PCA), but not limited to these methods. Here, m is the slope of the line, b is the intercept, and x and y are the coordinates of points on the line. Substituting the center points of each rivet's circular weld into the linear model yields the equation coefficients of the linear model.

[0124] Preferably, the linear model can also be represented as Where A, B, and C are the components of the direction vector of the line, (a,b,c) is the coordinates of a known point on the line, and (x,y,z) is the coordinates of any point on the line. It is worth noting that the equations that this line model needs to satisfy and the parameters used are for illustrative purposes only and are not intended to be limiting.

[0125] S62: Determine whether the distance between each circle center and the straight line model is greater than a set threshold. If it is greater, remove the rivet circular weld corresponding to the circle center; if it is not greater, leave it unchanged.

[0126] Specifically, the distance between the center point of the weld and the corresponding straight line model is calculated, and a distance threshold T2 is set. Welds with a distance less than the distance threshold are judged as normal welds, while welds with a distance greater than the distance threshold are judged as abnormal welds and are directly deleted.

[0127] S63: Determine whether the distance between any two centers of the remaining welds is within the set distance threshold range. If it is less than the threshold, remove two welds; if it is greater than the threshold, there is a problem of missed identification, and the final weld result is obtained.

[0128] Specifically, it is determined whether the distance between the centers of each weld is within the set distance threshold interval [T3, T4]. If the distance is less than the minimum threshold T3, the two welds are considered to be abnormal and removed. If the distance between the welds is greater than the maximum threshold T4, there is a problem of missed identification between the welds, which needs to be reported to the technical personnel for manual processing to obtain the final weld result. The threshold T2 and the threshold interval [T3, T4] are set in advance by those skilled in the art.

[0129] On the other hand, the present invention also provides a computer storage medium storing executable program code; the executable program code is used to execute any of the above-mentioned teachless welding methods or image recognition methods for riveted pipe clamps.

[0130] On the other hand, the present invention also provides a terminal device, including a memory and a processor; the memory stores program code that can be executed by the processor; the program code is used to execute any of the above-mentioned teachless welding methods or image recognition methods for riveted pipe clamps.

[0131] For example, the program code can be divided into one or more modules / units, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the program code in the terminal device.

[0132] The terminal device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and memory. Those skilled in the art will understand that the terminal device may also include input / output devices, network access devices, buses, etc.

[0133] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0134] The memory can be an internal storage unit of the terminal device, such as a hard drive or RAM. The memory can also be an external storage device of the terminal device, such as a plug-in hard drive, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card. Furthermore, the memory can include both internal and external storage units of the terminal device. The memory is used to store the program code and other programs and data required by the terminal device. The memory can also be used to temporarily store data that has been output or will be output.

[0135] The technical function and beneficial effects of the above-mentioned teachless welding method for rivet-type pipe clamps will not be elaborated here. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0136] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A teach-free welding method for riveted pipe clamps, characterized in that, include: S1: Obtain the point cloud of the pipe clamp workpiece; S2: Based on the point cloud of the pipe clamp workpiece, determine the plane equation of the pipe clamp workpiece, and divide the point cloud of the weld plane region and the point cloud of the rivet parameter region; S3: Divide the weld plane region point cloud and the rivet parameter region point cloud to obtain several weld plane sub-region point clouds and rivet parameter sub-region point clouds; S4: Determine the circular equation based on the point cloud of the rivet parameter sub-region; S5: Determine the plane equation of the weld seam based on the point cloud of the weld seam plane region, and project the circular equation onto the plane equation of the weld seam to obtain the circular weld seam of the rivet; The specific steps of step S4 include: Calculate the point cloud boundary of the point cloud of each rivet parameter sub-region to obtain the boundary point cloud; including: obtaining the normal direction of each point cloud and dividing the point cloud into several spheres; obtaining the average normal direction of the point cloud in each sphere, and determining whether the angle between the normal direction of the point and the corresponding average normal direction is less than a preset threshold. If it is not less than the threshold, it is a boundary point cloud. Based on the boundary point cloud, determine the circular equation; including: S421: Set a circular model, and randomly select several points from the boundary point cloud as the current interior points, fit and determine the parameters of the circular model, and obtain the current circular equation; S422: Determine the updated interior points based on the distance between each point in the boundary point cloud and the current circular equation, and count the number of updated interior points; S423: Determine whether the number of updated interior points is greater than the number threshold. If it is less, return to step S421; if it is not less, the final circular equation is obtained.

2. The teach-free welding method for riveted pipe clamps according to claim 1, characterized in that, The specific steps of step S1 include: Obtain the initial workpiece point cloud; The initial workpiece point cloud is filtered to obtain the filtered workpiece point cloud. A preset threshold is used to segment and filter the workpiece point cloud, resulting in the pipe clamp workpiece point cloud.

3. The teach-free welding method for riveted pipe clamps according to claim 1, characterized in that, The specific steps of step S2 include: S21: Set up a planar model, randomly select n points from the point cloud of the pipe clamp workpiece, fit and determine the parameters of the planar model, and obtain the current planar equation; S22: Determine the updated internal points based on the distance between each point in the point cloud of the pipe clamp workpiece and the current plane equation, and count the number of updated internal points; S23: Determine whether the number of updated internal points is greater than the quantity threshold. If it is less, return to step S21; if it is not less, the final plane equation is obtained. S24: Calculate the perpendicular distance from each point in the pipe clamp workpiece point cloud to the final plane equation, and determine whether the distance is greater than the set threshold. If it is less than the threshold, it is considered as the weld plane region point cloud; if it is not less than the threshold, it is considered as the rivet parameter region point cloud.

4. The teach-free welding method for riveted pipe clamps according to claim 1, characterized in that, The specific steps of step S3 include: S31: Cluster the point cloud of the weld plane region according to the distance to the adjacent points to obtain several weld plane sub-region point clouds; S32: Obtain the range of the point cloud of the weld plane sub-region, and filter the point cloud of the rivet parameter region according to the range to obtain several point clouds of the rivet parameter sub-region.

5. The teach-free welding method for riveted pipe clamps according to claim 4, characterized in that, The specific steps of step S31 include: S311: Calculate the distances between all points in the point cloud of the weld plane region and their adjacent points; S312: Randomly select a point in the point cloud and divide the point cloud into a weld plane sub-region where the distance between the point cloud and its neighboring points is less than a preset distance coefficient threshold. S313: Remove the point cloud of the weld plane sub-region and return to step S312 until all points of the weld plane region point cloud are divided into several weld plane sub-region point clouds.

6. The teach-free welding method for riveted pipe clamps according to any one of claims 1-5, characterized in that, The method further includes: Construct a straight line model based on the center of the circular weld of each rivet; Determine if the distance between each circle center and the straight line model is greater than a set threshold. If it is, remove the rivet circular weld corresponding to the circle center; otherwise, leave it unchanged. Determine whether the distance between any two center points of the remaining welds is within a set distance threshold range. If it is less than the threshold, remove two welds; if it is greater than the threshold, there is a problem of missed identification, and the final weld result is obtained.

7. A computer storage medium, characterized in that, It stores executable program code; the executable program code is used to perform the teach-free welding method for riveted pipe clamps according to any one of claims 1-6.

8. A terminal device, characterized in that, It includes a memory and a processor; the memory stores program code that can be executed by the processor; the program code is used to execute the teachless welding method for riveted pipe clamps according to any one of claims 1-6.

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