CN114663350B

CN114663350B - Track searching method, device and equipment for arc welding seam and storage medium

Info

Publication number: CN114663350B
Application number: CN202210152737.XA
Authority: CN
Inventors: 万章; 孔畅
Original assignee: Shanghai Friendess Electronic Technology Co ltd
Current assignee: Shanghai Friendess Electronic Technology Co ltd
Priority date: 2022-02-18
Filing date: 2022-02-18
Publication date: 2024-04-16
Anticipated expiration: 2042-02-18
Also published as: CN114663350A

Abstract

The invention discloses a track searching method, a track searching device, track searching equipment and a storage medium for arc welding seams. Wherein the method comprises the following steps: collecting points for arcs on the surface of a first workpiece to obtain a plurality of arc scattered points, and fitting and determining an original plane where the arc scattered points are located and a target circle formed by the original plane; collecting points for the straight line on the surface of the second workpiece to obtain a plurality of straight line scattered points, and fitting to determine the original straight line where the straight line is located; judging the spatial position relation between the original straight line and the original plane, and determining an intersection point which is closer to the circular arc scattered point in the intersection point of the original straight line and the target circle as a target starting point under the condition that the two are coplanar; under the condition of non-coplanarity, determining an intersection point which is closer to the circular arc scattered point in the intersection point of the auxiliary straight line and the target circle as a target starting point; determining a weld track and a track starting point of the arc weld based on the target circle and the target starting point; therefore, the method realizes the searching of the track and the starting point of the arc welding seam under different scenes in an intelligent mode, and has the advantages of high efficiency, accuracy and strong applicability.

Description

Track searching method, device and equipment for arc welding seam and storage medium

Technical Field

One or more embodiments of the present invention relate to the field of laser welding technologies, and in particular, to a method, an apparatus, a device, and a storage medium for searching a trajectory of a circular arc weld.

Background

In consideration of the problems of dimensional tolerance and the like of workpieces, after the initial positioning of the workpieces, the numerical control welding system also needs to further perform fine positioning on the welding seam track so as to improve the welding precision, and in the fine positioning, besides the welding seam track, the search of the welding seam starting point for defining the starting position of the track is also important.

Currently, a manual teaching method is generally adopted in the related art to perform the search of the weld track and the starting point. This solution is time-consuming, costly in terms of labor and low in repeatability, and once the welding scene is changed, the trajectory path originally taught is no longer suitable, which is particularly the case with circular arc welds. Therefore, how to improve the efficiency and applicability of the circular arc weld track search is a technical problem to be solved.

Disclosure of Invention

In view of this, one or more embodiments of the present invention provide a track searching method, apparatus, device and storage medium for arc welds.

In order to achieve the above object, one or more embodiments of the present invention provide the following technical solutions:

According to a first aspect of one or more embodiments of the present invention, there is provided a track searching method of a circular arc weld, the method including:

collecting points for arcs on the surface of a first workpiece to obtain a plurality of arc scattered points, fitting and determining an original plane where the arc scattered points are located in an original space, and fitting and determining a target circle formed by the arc scattered points in the original space based on the original plane and the arc scattered points;

collecting points for straight lines on the surface of a second workpiece to obtain a plurality of straight line scattered points, and fitting and determining original straight lines where the straight line scattered points are located in an original space;

judging the spatial position relation between the original straight line and the original plane;

under the condition that the original straight line is in the original plane, determining an intersection point which is closer to the circular arc scattered point among intersection points of the original straight line and the target circle as a target starting point; under the condition that the original straight line is not in the original plane, determining an intersection point which is closer to the circular arc scattered point among the intersection points of the auxiliary straight line and the target circle as a target starting point; the auxiliary straight line is determined by the intersection point of the original straight line and the original plane and the circle center of the target circle;

And determining a weld track and a track starting point of the arc weld based on the target circle and the target starting point.

In one embodiment, the fitting determines an original plane in which the circular arc scatter lies in an original space, including:

determining the scattered point distance between adjacent circular arc scattered points in an original space and the median of the scattered point distance, and filtering out circular arc scattered points with the scattered point distance exceeding a scattered point distance threshold value; wherein the scatter distance threshold is determined based on the median;

and fitting and determining an original plane where the filtered circular arc scattered points are located in the original space based on a least square method.

In one embodiment, the fitting determines an original plane in which the filtered circular arc scattered points lie in the original space, including:

after the original plane is obtained by fitting, determining the point-to-surface distances between each circular-arc scattered point and the original plane fitted at this time, and filtering and removing circular-arc scattered points with the point-to-surface distances exceeding a preset point-to-surface distance threshold;

and fitting the filtered arc scattered points again to obtain a new original plane again until the point-to-surface distances between all the arc scattered points and the original plane are within the point-to-surface distance threshold value and the number of the arc scattered points is not less than the preset scattered point number threshold value, and determining the final original plane.

In one embodiment, the fitting, based on the original plane and the circular arc scattered points, determines a target circle formed by the circular arc scattered points in an original space, including:

determining a mapping relation between an original plane and a projection space coordinate system;

mapping the filtered arc scattered points to a projection space based on the mapping relation to obtain corresponding projection arc scattered points, and fitting and determining a projection circle formed by the projection arc scattered points in the projection space;

and reflecting the projection circle to an original space based on the mapping relation to obtain a corresponding target circle.

In one embodiment, the fitting determines a projected circle formed by the projected arc scattered points in a projection space, including:

randomly selecting part of projection arc scattered points from the projection arc scattered points, fitting to obtain a projection circle formed by the selected projection arc scattered points, and determining the circle center and the radius of the projection circle fitted at this time;

determining the center distance between each projection arc scattered point and the center of the projection circle and the sum of the differences between the center distance and the radius of the projection circle according to the projection circle fitted each time;

and determining that the sum of the differences among the projection circles fitted for multiple times is minimum and the radius is within a preset radius threshold value as a final projection circle.

In one embodiment, the determining the spatial positional relationship between the original straight line and the original plane includes:

based on the mapping relation, mapping the filtered straight-line scattered points to a projection space to obtain corresponding projection straight-line scattered points, and fitting and determining projection straight lines where the projection straight-line scattered points are located in the projection space;

determining a spatial position relationship between the original straight line and the original plane based on a line-plane included angle between the projection straight line and a normal vector of the projection circle; under the condition that the line face included angle exceeds a preset line face included angle threshold value, determining that an original straight line is in an original plane; and under the condition that the line-to-line included angle does not exceed the line-to-line included angle threshold, determining that the original straight line is not in the original plane.

In one embodiment, the determining, as the target origin, an intersection point closer to the circular arc scattered point among the intersection points of the original straight line and the target circle includes:

determining an intersection point which is closer to a projection arc scattered point among intersection points of the projection straight line and the projection circle as a projection starting point;

and reversely mapping the projection starting point to an original space based on the mapping relation to obtain a corresponding target starting point.

In one embodiment, the determining, as the target origin, an intersection point closer to the circular arc scattered point among the intersection points of the auxiliary straight line and the target circle includes:

Determining an intersection point which is closer to a projection arc scattered point among intersection points of the projection auxiliary straight line and the projection circle as a projection starting point; the projection auxiliary straight line is determined by the intersection point of the projection straight line and the plane where the projection circle is located and the circle center of the target circle;

and reversely mapping the projection starting point to an original space based on the mapping relation to obtain a corresponding target starting point. According to a second aspect of one or more embodiments of the present invention, there is provided a trajectory searching device of an arc weld, the device including a point acquisition unit, a fitting unit, a judging unit, and a determining unit; wherein:

the point picking unit is used for picking points for the circular arcs on the surface of the first workpiece to obtain a plurality of circular arc scattered points; collecting points aiming at the straight line on the surface of the second workpiece to obtain a plurality of straight line scattered points;

the fitting unit is used for fitting and determining an original plane where the arc scattered points are located in an original space, and fitting and determining a target circle formed by the arc scattered points in the original space based on the original plane and the arc scattered points; fitting and determining an original straight line where the straight line scattered points are located in an original space;

the judging unit is used for judging the spatial position relationship between the original straight line and the original plane;

The determining unit is used for determining an intersection point which is closer to the circular arc scattered point among the intersection points of the original straight line and the target circle as a target starting point under the condition that the original straight line is in the original plane; under the condition that the original straight line is not in the original plane, determining an intersection point which is closer to the circular arc scattered point among the intersection points of the auxiliary straight line and the target circle as a target starting point; the auxiliary straight line is determined by the intersection point of the original straight line and the original plane and the circle center of the target circle; and determining a weld track and a track starting point of the arc weld based on the target circle and the target starting point.

According to a third aspect of one or more embodiments of the present invention, there is provided an electronic device comprising:

a processor, and a memory for storing processor-executable instructions;

wherein the processor implements the steps of the method of the first aspect described above by executing the executable instructions.

According to a fourth aspect of one or more embodiments of the present invention, a computer-readable storage medium is presented, on which a computer program is stored, which computer program, when being executed by a processor, carries out the steps of the method of the first aspect described above.

As can be seen from the above description, in the present invention, the straight line sampling point and the arc sampling point are respectively executed for the workpiece, the original straight line where the straight line sampling point and the arc sampling point are located is fitted based on the collected straight line scattering points, the original plane where the straight line sampling point and the target circle formed by the original plane are located is fitted based on the collected arc scattering points, then, the spatial position relationship between the original straight line and the original plane is judged, the target starting points are respectively determined in different manners under the condition that the original straight line and the original plane are coplanar and are not coplanar, and then, the weld seam track and the track starting point of the arc weld seam are determined by the target circle and the target starting points.

According to the scheme, the welding seam track of the arc welding seam and the track starting point are searched in an intelligent mode, the method has the advantages of being efficient and accurate, and the situation that workpieces are in different position relations is considered, so that the method is applicable to various welding scenes, and is high in applicability and repeatability.

Drawings

For a clearer description of the embodiments of the invention, or of the drawings that are required to be used in the description of the related art, it is obvious that the drawings in the following description are only parts of the embodiments of the invention, and that other drawings can be obtained from these drawings by a person skilled in the art without inventive faculty.

FIG. 1 is a schematic diagram of a welding scenario shown in an exemplary embodiment.

FIG. 2 is a flow chart of a trajectory search method for a circular arc weld provided by an exemplary embodiment;

FIG. 3 is a flow chart of a method for determining an original plane by fitting, as shown in an exemplary embodiment;

FIG. 4 is a flowchart of another method for determining an original plane by fitting, as shown in an exemplary embodiment;

FIG. 5 is a flowchart illustrating a method of fitting a determined target circle in accordance with an exemplary embodiment;

FIG. 6 is a flowchart illustrating a method for fitting a determined projected circle in accordance with an exemplary embodiment;

FIG. 7 is a flowchart illustrating a method of determining a spatial positional relationship between an original straight line and an original plane in accordance with an exemplary embodiment;

FIG. 8 is a schematic diagram of another welding scenario illustrated in an exemplary embodiment;

FIG. 9 is a schematic diagram of an electronic device according to an exemplary embodiment;

fig. 10 is a block diagram of a trajectory searching device for a circular arc weld provided in an exemplary embodiment.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary embodiments are not representative of all implementations consistent with one or more embodiments of the invention. Rather, they are merely examples of apparatus and methods that are consistent with aspects of one or more embodiments of the invention as detailed in the accompanying claims.

It should be noted that: in other embodiments, the steps of the corresponding method are not necessarily performed in the order shown and described. In some other embodiments, the method may include more or fewer steps than described herein. Furthermore, individual steps described in this disclosure may be broken down into multiple steps in other embodiments; while various steps described in this invention may be combined into a single step in other embodiments.

When a numerical control welding system performs welding, initial positioning is generally only rough determination of the position of a workpiece, and further fine positioning is generally required for the track and the starting point of a welding line in consideration of the problems of dimensional tolerance and the like of the workpiece.

At present, in the related art, a manual teaching method is mostly adopted to search a welding seam track and a starting point, in short, a track route is manually displayed once for a welding robot to memorize the track and the starting point of the welding seam, and a subsequent welding robot executes welding along the taught track route.

The scheme has the advantages that the consumed time and labor cost are high, the repeatability is low, once the welding scene is changed and different workpieces are faced, the original taught track route is not applicable any more, and the re-teaching is needed, so that the problems of low efficiency and poor applicability exist; in particular, in the case of arc welds, the above-mentioned drawbacks are not particularly applicable to different welding scenarios, even with a small number of non-manual solutions. Therefore, how to improve the efficiency and applicability of the circular arc weld track search is a technical problem to be solved.

In view of the above, the present invention provides a track searching method for arc welding seams, which is applied to various numerical control welding devices capable of applying vision technology. It is understood that the track search and welding of the arc weld may be performed by two components integrated in the same apparatus, or may be performed cooperatively by two apparatuses in a numerical control welding system, which is not particularly limited in the present invention.

Referring to fig. 1, fig. 1 is a schematic diagram illustrating a welding scenario according to an exemplary embodiment of the present invention.

At least two workpieces are included in the welding scene; the first workpiece is a workpiece with a surface capable of collecting arc scattered points, the arc scattered points can be located on an arc welding seam to be welded, the second workpiece is a workpiece with a surface capable of collecting straight line scattered points, and the straight line where the straight line scattered points are located is generally close to the arc welding seam in space position.

The arc welding seam to be welded is positioned on the first workpiece, and the electronic equipment for performing track searching searches to determine the welding seam track and the track starting point of the arc welding seam on the surface of the first workpiece so as to perform welding.

Referring to fig. 2, fig. 2 is a flowchart illustrating a track searching method of a circular arc welding seam according to an exemplary embodiment.

The track searching method of the arc welding seam comprises the following specific steps:

step 202, collecting points of an arc on the surface of a first workpiece to obtain a plurality of arc scattered points, fitting and determining an original plane where the arc scattered points are located in an original space, and fitting and determining a target circle formed by the arc scattered points in the original space based on the original plane and the arc scattered points.

In this embodiment, the track search of the arc welding seam and the collection of the arc/linear scattered points may be performed by two components integrated in the same device, or may be performed cooperatively by two devices in the numerical control welding system, which is not particularly limited. For example, the laser seam finder can be used for picking points, and other devices with better computing power can be used for searching tracks; the specific content of the laser seam finder in performing scattered point acquisition can be referred to the related principle, and will not be described herein.

After the arc scattered points are acquired, an original plane where the arc scattered points are located in an original space and a target circle formed by the arc scattered points in the original space can be fitted and determined; where the original space refers to a real physical space, however, it is understood that the original space is actually a virtual space that is also built based on the perspective of the device, and there may be mapping transformations of the spatial coordinate system between different devices.

In order to enable those skilled in the art to more clearly understand the technical solutions provided in the present invention, in the following, the relevant contents of the fitting determination of the original plane and the target circle in step 202 are respectively described.

Fitting and determining an original plane where the circular arc scattered points are located in an original space:

the original plane is the plane where the arc scattered points are located in the original space, and is the plane where the arc welding line is located under the condition that the collected arc scattered points are located above the arc welding line to be welded; in the process of fitting and determining an original plane, the initially acquired circular arc scattered points are generally required to be filtered so as to remove abnormal points and avoid fitting failure.

Referring to fig. 3, fig. 3 is a flowchart illustrating a method for determining an original plane by fitting, in an alternative implementation, in step 202, the determining the original plane where the circular arc scattered points are located in the original space may include:

a02, determining the scattered point distance between adjacent circular arc scattered points in an original space and the median of the scattered point distance, and filtering and removing the circular arc scattered points with the scattered point distance exceeding a scattered point distance threshold value; wherein the scatter distance threshold is determined based on the median.

And step A04, fitting and determining an original plane where the filtered circular arc scattered points are located in an original space based on a least square method.

Assuming that the collected arc scattered points aS1 to aS6 are adjacent to each other in the original space, the arc scattered points aS1 and aS2, aS2 and aS3, aS3 and aS4, aS4 and aS5, and the scattered point distances D-aS12 (1.0 mm), D-aS23 (4.7 mm), D-aS34 (1.2 mm), D-aS45 (1.7 mm), and D-aS56 (1.5 mm) between the arc scattered points aS5 and aS6 are determined, and the median D-aS56 (1.5 mm) of the scattered point distances is determined.

Based on the median, determining the 3 times value of the median as a scatter distance threshold, namely determining the scatter distance threshold as 0.45mm; and comparing each scattered point distance with a scattered point distance threshold value, and eliminating arc scattered points aS2 and aS3 corresponding to the scattered point distance D-aS23 (4.7 mm) which is larger than the scattered point distance threshold value (4.5 mm). It is understood that the manner of setting the scatter distance threshold is not limited to the above-described manner of median multiple.

Fitting the filtered arc scattered points aS1, aS4, aS5 and aS6 by adopting a least square method, and determining an original plane where the filtered arc scattered points aS1, aS4, aS5 and aS6 are located in an original space; details of the fitting plane based on the least squares method can be found in the related principles, and will not be described here. It will be appreciated that the algorithm for fitting the determined original plane is not limited to the least squares method described above.

It should be noted that, the specific number of the arc scattered points, the scattered point distance and the specific numerical value of the scattered point distance threshold value obtained by the collection are only used for illustration, and do not limit the scheme; in a real scene, the actual number of the acquired circular arc scattered points should be more, and the actual values of the scattered point distance and the scattered point distance threshold value influence the fertility.

In order to further improve the accuracy of the fitted original plane, referring to fig. 4, fig. 4 is a flowchart illustrating another method for determining an original plane by fitting according to an exemplary embodiment, in an alternative implementation, in step a04, the determining an original plane where the filtered circular arc scattered points are located in the original space by fitting may include:

and step A042, after the original plane is obtained by fitting, determining the point-surface distances between each circular-arc scattered point and the original plane fitted at this time, and filtering and removing the circular-arc scattered points with the point-surface distances exceeding a preset point-surface distance threshold value.

And (A044) fitting the filtered circular arc scattered points again to obtain a new original plane again until the point-to-surface distances between all the circular arc scattered points and the original plane are within the point-to-surface distance threshold value and the number of the circular arc scattered points is not less than the preset scattered point number threshold value, and determining the final original plane.

Based on the previous example, it is assumed that after the arc scattered points aS1, aS4, aS5, and aS6 are fitted to obtain the original plane oP1 based on the least square method, the point-to-plane distances D-SP11 (0.2 mm), D-SP41 (0.2 mm), D-SP51 (0.7 mm), and D-SP61 (0.4 mm) between the arc scattered points aS1, aS4, aS5, and aS6 and the original plane oP1 to which the present time was fitted are determined.

And comparing the point-surface distance of each circular-arc scattered point with a preset point-surface distance threshold value, and eliminating the circular-arc scattered point aS5 corresponding to the point-surface distance D-SP51 (0.7 mm) which is larger than the preset point-surface distance threshold value (0.5 mm). It will be appreciated that the point-to-face distance threshold may be set to suit the actual accuracy requirements.

And fitting the filtered arc scattered points aS1, aS4 and aS6 by adopting a least square method again to obtain an original plane oP2 where the filtered arc scattered points aS1, aS4 and aS6 are located in an original space, and determining the original plane oP2 aS a final original plane under the condition that the point-to-plane distances D-SP12 (0.2 mm), D-SP42 (0.2 mm) and D-SP62 (0.3 mm) between the arc scattered points aS1, aS4 and aS6 and the original plane oP2 are all within a point-to-plane distance threshold (0.5 mm) and the number (3) of the rest arc scattered points is larger than a preset scattered point number threshold (one third of the number of the arc scattered points which are initially acquired and 2). It is to be understood that the manner of setting the threshold value of the number of scattering points is not limited to the above manner.

It should be noted that, in a real scene, the actual number of the acquired circular arc scattered points should be greater, and the actual number of times of performing the original plane fitting should be greater.

Fitting and determining a target circle formed by the circular arc scattered points in the original space:

the target circle is a circular track which can be formed by arc scattered points in an original space, and is a welding seam track of an arc welding seam under the condition that the acquired arc scattered points are positioned above the arc welding seam to be welded; in the process of fitting and determining the target circle, in order to facilitate calculation and ensure smooth proceeding of the fitting of the target circle, the circular arc scattered points can be filtered and mapped and converted.

Referring to fig. 5, fig. 5 is a flowchart illustrating a method for determining a target circle by fitting, in an alternative implementation, in step 202, the determining, by fitting, a target circle formed by the arc scattering points in an original space based on the original plane and the arc scattering points may include:

and step B02, determining the mapping relation between the original plane and the projection space coordinate system.

And step B04, mapping the filtered circular arc scattered points to a projection space based on the mapping relation to obtain corresponding projection circular arc scattered points, and fitting and determining a projection circle formed by the projection circular arc scattered points in the projection space.

And step B06, reflecting the projection circle to an original space based on the mapping relation to obtain a corresponding target circle.

After an original plane is determined, the original plane is rotated by taking the original plane parallel to an xOy plane in a projection space as a target, and a mapping matrix used for rotation when the original plane reaches a target position is determined, wherein the mapping matrix represents a mapping relation between the original plane and a projection space coordinate system, namely a mapping relation between the original space and the projection space; the details of determining this mapping matrix may be found in the relevant principles and will not be described in detail herein.

After the mapping matrix is determined, mapping the filtered arc scattered points to a projection space to obtain projection arc scattered points corresponding to the arc scattered points respectively, and fitting and determining projection circles formed by the projection arc scattered points in the projection space based on the mapping matrix; the filtered circular arc scattered points can be the circular arc scattered points remained after the circular arc scattered points are removed when the original plane is fitted, however, it is understood that in the process of fitting and determining the projection circle, the projection circular arc scattered points are generally required to be filtered.

And reflecting the projection circle to an original space based on inverse operation of the mapping matrix, so as to obtain a corresponding target circle.

It should be noted that, the fitting determination of the target circle may be performed in the original space, however, the circular arc scattered points are mapped to the projection space in a manner that the original plane is parallel to the xOy plane, and then the projection circle is fitted and reflected in the projection space to obtain the target circle, so that the effects of reducing the calculation amount and improving the calculation precision can be achieved.

Referring to fig. 6, fig. 6 is a flowchart illustrating a method for determining a projected circle by fitting, in an alternative implementation manner, in step B04, the determining a projected circle formed by the projected arc scattered points in a projection space by fitting may include:

and step B042, randomly selecting part of projection arc scattered points from the projection arc scattered points, fitting to obtain a projection circle formed by the selected projection arc scattered points, and determining the circle center and the radius of the projection circle fitted at this time.

And B044, determining the center distance between each projection arc scattered point and the center of the projection circle and the sum of the differences between the center distances and the radius of the projection circle according to the projection circles fitted each time.

And step B046, determining that the sum of the differences among the projection circles fitted for a plurality of times is minimum and the radius is within a preset radius threshold value as a final projection circle.

Assuming that the projected arc scattered points obtained by mapping comprise projected arc scattered points paS to paS, 3 projected arc scattered points are selected each time to fit a projected circle, and a total of 20 projected circles can be obtained by fitting. For example, fitting the projected circular arc scatter paS, paS2, and paS3 can result in a projected circle pC123. It is understood that the manner of fitting the projected circle is not limited to the three-point fitting circle described above.

And determining the circle center and the radius of each projection circle and the difference value between the circle center distance from each projection circular arc scattered point to the circle center and the radius, and summing the difference values between the circle center distances and the radii of all projection circular arc scattered points to obtain the sum of the difference values of the projection circles. For example, for a projected circle pC123 with a radius R1, the center distances D-SC41, D-SC51, and D-SC61 between the projected circular arc scattered points paS, paS5, and paS6 and the center thereof may be determined, and then differences between the respective center distances and the radius R1 may be determined, and the sum of the differences of the projected circle pC123 may be summed (D-sc41+d-sc51+d-SC 61-3R 1).

Of the 20 projected circles obtained by fitting, if the sum of the differences of the projected circles pC123 is minimum and the radius R1 thereof is within a preset radius threshold, it can be determined that the projected circle pC123 is the final projected circle. It will be appreciated that the radius threshold may be set based on workpiece standard size and accuracy requirements.

And 204, collecting points of the straight line on the surface of the second workpiece to obtain a plurality of straight line scattered points, and fitting and determining an original straight line where the straight line scattered points are located in an original space.

In this embodiment, after the device such as the laser seam finder acquires the straight-line scattered points, the original straight line where the straight-line scattered points are located in the original space may be determined by fitting. In the process of fitting and determining the original straight line, filtering the initially collected straight line scattered points is generally needed to remove abnormal points, so that fitting failure is avoided; the specific algorithm used for fitting and determining the original straight line can be referred to as the related principle, and is not limited herein, for example, the fitting of the original straight line can be implemented by using a least square method.

It will be appreciated that in steps 202 to 204, if the fitting of the original plane, the target circle and the original straight line fails, it may be determined that the track search of the arc weld fails, and no further steps are performed.

Step 206, judging the spatial position relationship between the original straight line and the original plane;

in this embodiment, by determining the spatial position relationship between the plane where the circular arc scattered points are located and the straight line where the straight line scattered points are located, the spatial position relationship between the first workpiece and the second workpiece is clarified, so that the track starting point of the circular arc welding seam is positioned in a manner suitable for the spatial position relationship, and the method can be flexibly suitable for different welding scenes and different workpieces.

The determination of the spatial positional relationship between the original straight line and the original plane may also be performed in the projection space based on the aforementioned implementation of determining the target circle from the projection circle fitted in the projection space.

Referring to fig. 7, fig. 7 is a flowchart illustrating a method for determining a spatial position relationship between an original straight line and an original plane according to an exemplary embodiment, in an alternative implementation, in step 206, the determining the spatial position relationship between the original straight line and the original plane may include:

step 2062, based on the mapping relation, mapping the filtered straight-line scattered points to a projection space to obtain corresponding projection straight-line scattered points, and fitting and determining the projection straight lines where the projection straight-line scattered points are located in the projection space.

Step 2064, determining a spatial position relationship between the original straight line and the original plane based on a line-plane included angle between the projection straight line and a normal vector of the projection circle; under the condition that the line face included angle exceeds a preset line face included angle threshold value, determining that an original straight line is in an original plane; and under the condition that the line-to-line included angle does not exceed the line-to-line included angle threshold, determining that the original straight line is not in the original plane.

After a mapping matrix used for coordinate conversion between an original space and a projection space is determined, the linear scattered points can be mapped to the projection space based on the mapping matrix to obtain corresponding projection linear scattered points, and projection lines where the projection linear scattered points are located in the projection space are determined in a fitting mode; alternatively, the fitted original straight line may be mapped to a projection space based on the mapping matrix to obtain a corresponding projection straight line.

Then, the spatial positional relationship of the projected straight line and the projected circle in the projected space is judged, which should be coincident with the spatial positional relationship between the original straight line and the target circle in the original space. Specifically, the cosine value of the line-plane included angle between the projection straight line and the normal vector of the projection circle can be calculated to determine the spatial position relationship of the projection straight line and the projection circle, and the closer the cosine value of the line-plane included angle is to 0, the closer the line-plane included angle between the projection straight line and the plane of the projection circle is to 90 degrees, which means that the higher the coplanarity possibility of the projection straight line and the plane of the projection circle is. It is understood that the line-to-plane angle threshold may be set in accordance with actual accuracy requirements.

For example, it may be determined that the line-to-plane angle exceeds the threshold value and the original straight line is in the original plane if the cosine value of the line-to-plane angle between the projected straight line and the normal vector of the target circle does not exceed 0.25; and under the condition that the cosine value of the included line-plane angle is larger than 0.25, determining that the included line-plane angle does not exceed the threshold value, and the original straight line is not in the original plane.

Step 208, determining an intersection point which is closer to the circular arc scattered point among the intersection points of the original straight line and the target circle as a target starting point under the condition that the original straight line is in the original plane; under the condition that the original straight line is not in the original plane, determining an intersection point which is closer to the circular arc scattered point among the intersection points of the auxiliary straight line and the target circle as a target starting point; the auxiliary straight line is determined by the intersection point of the original straight line and the original plane and the circle center of the target circle. When the target starting point is determined in this step, the point of intersection closer to the circular arc scatter point among the points of intersection of the original straight line and the target circle is determined as the target starting point, namely, for any circular arc scatter point, when the original straight line is in the original plane; and under the condition that the original straight line is not in the original plane, determining an intersection point which is closer to the circular arc scattered point among the intersection points of the auxiliary straight line and the target circle as a target starting point.

In order to enable those skilled in the art to more clearly understand the technical solution provided by the present invention, the following description will respectively describe the related content of determining the target starting point under two spatial position relationships in step 208.

The original straight line is in the original plane:

in the welding scenario shown in fig. 1, the original straight line where the straight line scatter is located in the original plane where the arc scatter is located, that is, the straight line scatter and the arc scatter are coplanar, and under the spatial position relationship, it can be determined that an intersection point closer to the arc scatter among intersections of the original straight line and the target circle is the target origin.

Based on the implementation manner of performing the spatial position relationship determination in the projection space, in step 208, the determining, as the target starting point, the intersection point closer to the circular arc scatter point among the intersections of the original straight line and the target circle includes:

determining an intersection point which is closer to a projection arc scattered point among intersection points of the projection straight line and the projection circle as a projection starting point; and reversely mapping the projection starting point to an original space based on the mapping relation to obtain a corresponding target starting point.

Under the condition that the line-plane included angle between the projection straight line and the normal vector of the projection circle exceeds the line-plane included angle threshold, the original straight line is determined to be in an original plane, the intersection point of the original straight line and the target circle is mapped to a projection space, namely the intersection point of the projection straight line and the projection circle, the intersection point coordinates of the projection straight line and the projection circle are calculated in the projection space, the intersection point which is closer to the projection arc scattered point in the intersection point is determined to be a projection starting point, and then the projection starting point is reversely mapped to the original space based on the inverse operation of the mapping matrix to obtain the coordinates of the target starting point.

It can be appreciated that, in addition to the case where the original straight line on the same plane intersects the target circle, in a few scenarios, there may be a tangent, and no intersection; and determining a tangent point as a target starting point when the arc welding line is tangent, and determining that the track search of the arc welding line fails when the arc welding line is not tangent, so that the follow-up steps are not executed.

(II) the original straight line is not in the original plane:

referring to fig. 8, fig. 8 is a schematic diagram illustrating another welding scenario according to an exemplary embodiment.

In the welding scenario shown in fig. 8, the original straight line where the straight line scatter is located is not located in the original plane where the arc scatter is located, that is, the straight line scatter and the arc scatter are not coplanar, under such a spatial positional relationship, an auxiliary straight line can be determined by an intersection point of the plane where the original straight line and the target circle are located and a circle center of the target circle, and an intersection point closer to the arc scatter among the intersection points of the auxiliary straight line and the target circle is the target origin.

Based on the implementation manner of performing the spatial position relationship determination in the projection space, in step 208, the determining, as the target starting point, an intersection point closer to the circular arc scatter point from among the intersections of the auxiliary straight line and the target circle includes:

Determining an intersection point which is closer to a projection arc scattered point among intersection points of the projection auxiliary straight line and the projection circle as a projection starting point; the projection auxiliary straight line is determined by the intersection point of the projection straight line and the plane where the projection circle is located and the circle center of the target circle; and reversely mapping the projection starting point to an original space based on the mapping relation to obtain a corresponding target starting point.

Under the condition that the line-plane included angle between the projection straight line and the normal vector of the projection circle does not exceed the line-plane included angle threshold, the original straight line is determined not to be in the original plane, the auxiliary straight line is mapped to the projection space, namely, the projection auxiliary straight line determined by the intersection point of the projection straight line and the plane where the projection circle is located and the circle center of the projection circle, the intersection point of the auxiliary straight line and the target circle is mapped to the projection space, namely, the intersection point coordinate of the projection auxiliary straight line and the projection circle is calculated in the projection space, the intersection point which is closer to the projection arc scattered point in the intersection point is determined to be the projection starting point, and then the projection starting point is reversely mapped to the original space based on the inverse operation of the mapping matrix to obtain the coordinate of the target starting point.

Step 210, determining a weld track and a track start point of the arc weld based on the target circle and the target start point.

After the target circle and the target starting point are determined, the welding line track and the track starting point of the arc welding line can be determined, and under the condition that the collected arc scattered points are positioned above the arc welding line to be welded, the target circle is the welding line track of the arc welding line, and the target starting point is the track starting point of the arc welding line.

After the weld track and the track starting point of the arc weld are determined, the related equipment can execute the welding of the arc weld; more commonly, parameters such as the radius and normal vector of the target circle, and the spatial coordinates of the target origin may be indicated to the relevant equipment to cause it to perform welding based on the parameters.

As can be seen from the above description, in the present invention, the straight line sampling point and the arc sampling point are respectively executed for the workpiece, the original straight line where the straight line sampling point and the arc sampling point are located is fitted based on the collected straight line scattering points, the original plane where the straight line and the target circle formed by the original plane are fitted based on the collected arc scattering points, then the spatial position relationship between the original straight line and the original plane is judged, the target starting points are respectively determined in different manners under the condition that the original straight line and the original plane are coplanar and non-coplanar, and then the weld track and the track starting point of the arc weld are determined by the target circle and the target starting points.

Fig. 9 is a schematic structural diagram of an electronic device where a track searching device for arc welding seams is located according to an exemplary embodiment. Referring to fig. 9, at a hardware level, the device includes a processor 902, an internal bus 904, a network interface 906, a memory 908, and a nonvolatile storage 910, although other hardware required by other services is also possible. One or more embodiments of the invention may be implemented in software, such as by the processor 902 reading corresponding computer instructions from the non-volatile storage 910 into the memory 908 and then running. Of course, in addition to software implementation, one or more embodiments of the present invention do not exclude other implementation, such as a logic device or a combination of software and hardware, etc., that is, the execution subject of the following process flows is not limited to each logic unit, but may also be hardware or a logic device.

Referring to fig. 10, fig. 10 is a block diagram of a track searching device for a circular arc welding seam according to an exemplary embodiment, which can be applied to the electronic device shown in fig. 9 to implement the technical scheme of the present invention. The track searching device of the arc welding seam comprises a point collecting unit 1010, a fitting unit 1020, a judging unit 1030 and a determining unit 1040:

The point picking unit 1010 is configured to pick points for an arc on the surface of the first workpiece to obtain a plurality of arc scattered points; collecting points aiming at the straight line on the surface of the second workpiece to obtain a plurality of straight line scattered points;

the fitting unit 1020 is configured to determine, by using a fitting method, an original plane in which the arc scattered points are located in an original space, and determine, by using a fitting method, a target circle formed by the arc scattered points in the original space based on the original plane and the arc scattered points; fitting and determining an original straight line where the straight line scattered points are located in an original space;

the judging unit 1030 is configured to judge a spatial position relationship between the original straight line and the original plane;

the determining unit 1040 is configured to determine, when the original straight line is in the original plane, an intersection point, which is closer to the circular arc scattered point, among intersection points of the original straight line and the target circle, as a target origin; under the condition that the original straight line is not in the original plane, determining an intersection point which is closer to the circular arc scattered point among the intersection points of the auxiliary straight line and the target circle as a target starting point; the auxiliary straight line is determined by the intersection point of the original straight line and the original plane and the circle center of the target circle; and determining a weld track and a track starting point of the arc weld based on the target circle and the target starting point.

Optionally, the fitting unit 1020 is specifically configured to, when the fitting determines an original plane in which the circular arc scattered points are located in the original space:

Optionally, the fitting unit 1020 is specifically configured to, when the fitting determines the original plane in which the filtered circular arc scattered points are located in the original space:

Optionally, the fitting unit 1020 is specifically configured to, when determining, based on the original plane and the circular arc scattered points, a target circle formed by the circular arc scattered points in the original space in a fitting manner:

Optionally, the fitting unit 1020 is specifically configured to, when fitting the projected circle formed by the projected circular arc scattered points in the projection space:

determining the center distance between each projection arc scattered point and the center of the projection circle and the sum of the differences between the center distance and the radius of the projection circle according to the projection circles fitted each time;

Alternatively, the determining unit 1030 is specifically configured to, when determining the spatial positional relationship between the original straight line and the original plane:

Alternatively, the determining unit 1040 is specifically configured to, when determining, as the target starting point, an intersection point closer to the circular arc scatter point among the intersection points of the original straight line and the target circle:

Reversely mapping the projection starting point to an original space based on the mapping relation to obtain a corresponding target starting point;

the determining unit 1040, when determining, as the target origin, an intersection point closer to the circular arc scattered point among the intersection points of the auxiliary straight line and the target circle, is specifically configured to:

The system, apparatus, module or unit set forth in the above embodiments may be implemented in particular by a computer chip or entity, or by a product having a certain function. A typical implementation device is a computer, which may be in the form of a personal computer, laptop computer, cellular telephone, camera phone, smart phone, personal digital assistant, media player, navigation device, email device, game console, tablet computer, wearable device, or a combination of any of these devices.

In a typical configuration, a computer includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, read only compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic disk storage, quantum memory, graphene-based storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by the computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

The foregoing describes certain embodiments of the present invention. Other embodiments are within the scope of the following claims. In some cases, the actions or steps recited in the claims can be performed in a different order than in the embodiments and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

The terminology used in one or more embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of one or more embodiments of the invention. As used in one or more embodiments of the invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any or all possible combinations of one or more of the associated listed items.

It should be understood that while the terms first, second, third, etc. may be used in one or more embodiments of the invention to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of one or more embodiments of the invention. The word "if" as used herein may be interpreted as "at … …" or "at … …" or "responsive to a determination", depending on the context.

The foregoing description of the preferred embodiment(s) of the invention is not intended to limit the embodiment(s) of the invention, but is to be accorded the widest scope consistent with the principles and spirit of the embodiment(s) of the invention.

Claims

1. A track search method for an arc weld, the method comprising:

collecting points for straight lines on the surface of a second workpiece to obtain a plurality of straight line scattered points, and fitting and determining original straight lines where the plurality of straight line scattered points are located in an original space;

under the condition that the original straight line is positioned on the original plane, determining an intersection point which is closer to an arc scattered point among intersection points of the original straight line and the target circle as a target starting point; under the condition that the original straight line is not located on the original plane, determining an intersection point which is closer to an arc scattered point among intersection points of the auxiliary straight line and the target circle as a target starting point; the auxiliary straight line is determined by the intersection point of the original straight line and the original plane and the circle center of the target circle;

2. The method of claim 1, wherein the fitting determines an original plane in which the arc scatter lies in an original space, comprising:

3. The method of claim 2, wherein the fitting determines an original plane in which the filtered circular arc scatter lies in the original space, comprising:

4. The method of claim 1, wherein the fitting the target circle formed by the circular-arc scattered points in the original space based on the original plane and the circular-arc scattered points comprises:

5. The method of claim 4, wherein the fitting determines a projected circle of the projected arc scatter in projection space, comprising:

6. The method of claim 4, wherein said determining a spatial positional relationship between said original straight line and said original plane comprises:

7. The method of claim 6, wherein determining an intersection point closer to the circular arc scatter among the intersection points of the original straight line and the target circle as the target start point comprises:

8. The method according to claim 6 or 7, wherein determining an intersection point closer to the circular arc scatter among the intersection points of the auxiliary straight line and the target circle as the target origin point includes:

9. The track searching device of the arc welding seam is characterized by comprising a point collecting unit, a fitting unit, a judging unit and a determining unit; wherein:

the determining unit is used for determining that an intersection point which is closer to the circular arc scattered point among the intersection points of the original straight line and the target circle is a target starting point under the condition that the original straight line is in the original plane; under the condition that the original straight line is not in the original plane, determining an intersection point which is closer to the circular arc scattered point among the intersection points of the auxiliary straight line and the target circle as a target starting point; the auxiliary straight line is determined by the intersection point of the original straight line and the original plane and the circle center of the target circle; and determining a weld track and a track starting point of the arc weld based on the target circle and the target starting point.

10. An electronic device, comprising:

a processor, and a memory for storing processor-executable instructions;

wherein the processor implements the steps of the method of any one of claims 1 to 8 by executing the executable instructions.

11. A computer-readable storage medium, characterized in that a computer program is stored thereon, which, when being executed by a processor, realizes the steps in the method of any of claims 1 to 8.