CN117226844A - Steel structural member welding method and system based on robot welding - Google Patents

Abstract

The application belongs to the technical field of welding, and provides a welding method and a welding system for a steel structural member based on robot welding, wherein the method comprises the steps of firstly constructing a structural model of the steel structural member; then, planning locating and welding tracks according to the structural model; specifically, determining weld information to be welded from a structural model; planning a motion trail in a preset motion control strategy, a locating process strategy and a welding process strategy according to the structural model and the welding seam information; finally, controlling the robot to weld the steel structural member according to the planned locating and welding track; by means of the structural model and according to the structural model and the welding seam information, the motion trail is planned in a preset motion control strategy, a locating process strategy and a welding process strategy, dependence on a machine vision technology is reduced, an effective welding trail is obtained, and working stability of the whole welding process is improved.

Description

Steel structural member welding method and system based on robot welding

Technical Field

The application belongs to the technical field of welding, and particularly relates to a welding method and system for a steel structural member based on robot welding.

Background

The steel structure industry has large welding demand and high flexibility requirement, and is a field which is difficult to solve by robot welding. The flexibility requirement of the steel structure industry is mainly met in two aspects, namely the requirement of production replacement efficiency is firstly met, the shape and the size of the steel components are based on the actual requirement of a main field of industry, the steel structure industry is completely non-calibrated and manufactured, the requirement that the production replacement speed is close to the mass production speed is required to be achieved, and the requirement of the steel structure industry can not be achieved at all by using a tool positioning and teaching programming mass welding solution for traditional robot welding; secondly, the requirement of workpiece size deviation compensation is that the steel member is large in general size, relatively low in assembly precision and stable in welding only by adopting a weld seam locating function during welding.

The inventor finds that the flexibility requirement of the steel structure industry is mostly met by adopting a machine vision mode in the current industry, but the problems of high visual cost and poor stability are always obstructing the popularization of the solution, and an effective welding track cannot be obtained.

Disclosure of Invention

In order to solve the problems, the application provides a method and a system for welding a steel structural member based on robot welding.

In order to achieve the above object, the present application is realized by the following technical scheme:

in a first aspect, the present application provides a method for welding a steel structural member based on robot welding, comprising:

obtaining a structural model of a steel structural member;

planning locating and welding tracks according to the structural model; specifically, determining weld information to be welded from the structural model; planning a motion trail in a preset motion control strategy, a locating process strategy and a welding process strategy according to the structural model and the welding seam information;

and controlling the robot to weld the steel structural member according to the planned locating and welding track.

Further, the steel structural member is integrally photographed, and an integral point cloud model of the member is obtained.

Further, presetting various component node types in offline programming software; selecting a preset node according to the node type of the actual component, inputting a corresponding size, and generating a component containing the node in software; and continuously selecting preset node types and input sizes according to the node types and the sizes of the actual components to perform permutation and combination, so as to obtain a three-dimensional model of the actual components.

Further, the sizes of steel column feet, rib plates, brackets and connecting plates in the steel structural member are obtained; establishing a steel column model according to the flange plate width, the web plate width, the flange plate thickness, the web plate thickness, the fillet size and the steel column length of the steel column; selecting preset column foot nodes, and obtaining a column foot model on the steel column according to the length, width and thickness of the column foot at one end of the steel column, the number of triangular rib plates on the column foot, the distance between the triangular rib plates, the length of the triangular rib plates, the width of the triangular rib plates, the chamfer angle of the triangular rib plates and the thickness of the triangular rib plates; selecting preset rib plate nodes, obtaining a rib plate model on the steel column according to the distance of the rib plate at one end of the steel column, the height of the rib plate, the thickness of the rib plate and the chamfer size of the rib plate, copying the shape size of the rib plate, and only changing the position size to obtain a plurality of rib plate models on the steel column; selecting preset bracket nodes, and obtaining a bracket model according to the distance of the bracket at one end of the steel column, the length width and the inclination of the bracket, the plate thickness dimension of the outer contour, and the positions and the plate thickness dimension of a plurality of rib plates in the bracket; and selecting preset connecting plate nodes, obtaining a connecting plate model according to the distance between the connecting plate and one end of the steel column, the distance between the connecting plate and the edge of the steel column, the width of the connecting plate and the thickness of the connecting plate, copying the shape and the size of the connecting plate, and only changing the position and the size to obtain a plurality of connecting plate models.

Further, the locating process strategy comprises the steps of selecting one or more component pairing deviation forms according to the phenomena of different field pairing precision according to the field actual situation; the group deviation forms include a normal deviation, a longitudinal deviation, and a dimensional deviation.

Further, when the conventional deviation locating is adopted, three locating points are made at one end of the welding line in three directions of XYZ, the position of an end point is calculated, and then the welding line automatically extends to the other end according to the length of the welding line, so that an actual welding track is obtained;

for a double-sided fillet weld vertical to the component, three locating points are made at one end of the weld in three directions of XYZ, the position of the end point is calculated, and then the welding points automatically extend to the other end according to the length of the weld, so that an actual welding track is obtained; three locating points are made on a three-face fillet weld vertical to the component in the three-face welding line crossing point in the three directions of XYZ, the crossing position of the three-face welding line is calculated, and then the three-face fillet weld extends from the crossing position to the tail end of the three-face welding line according to the length of the welding line, so that an actual welding track is obtained; for a four-side fillet weld vertical to the component, three searching points are respectively made in the three directions of XYZ at two intersecting points, two end points of one welding line are calculated, and then the two end points extend to the tail ends of the other four welding lines according to the length of the welding line, so that an actual welding track is obtained; and (3) carrying out three searching points on a pentagonal welding line perpendicular to the component at four intersecting points in three directions of XYZ, calculating two end points of the four welding lines, and extending from the two end points to the tail ends of the other four welding lines according to the length of the welding lines to obtain an actual welding track.

Furthermore, when adopting the longitudinal deviation locating strategy, the locating points are reduced on the basis of the conventional deviation locating strategy.

Further, when adopting a size deviation locating strategy, three locating points are made in three directions of XYZ at one end of a welding line, the position of an end point is calculated, then the welding line extends to the other end according to the length of the welding line, three locating points are made in the XYZ direction of the other end, the position of the other end point is calculated, and the two end points are connected to obtain an actual welding track; for a two-sided fillet weld, three locating points are made in three directions of XYZ at one end of the weld, the position of an end point is calculated, then the welding points extend to the other end according to the length of the weld, three locating points are made in the XYZ direction of the other end, the position of the other end point is calculated, and the two end points are connected to obtain an actual welding track; for a three-sided angle weld, three locating points are made in the three directions of XYZ at the crossing points of the three weld, the crossing positions of the three weld are calculated, then the other three weld extends to the tail end, three locating points are respectively made in the XYZ directions of the other three tail end points, the positions of the other three end points are calculated, and the crossing positions and the other three end points are respectively connected to obtain an actual welding track; for one four-side fillet weld, three locating points are respectively formed in the two intersecting points in the XYZ directions, two end points of one weld are calculated, then the other four welds extend to the tail end, three locating points are respectively formed in the XYZ directions of the other four tail end points, the positions of the other four end points are calculated, and the two end points and the other four end points of the middle weld are respectively connected to obtain an actual welding track; for a pentagonal welding seam, three locating points are respectively made in the directions of XYZ at four intersecting points, two end points of four welding seams are calculated, then the four welding seams extend to the tail ends, three locating points are respectively made in the directions of XYZ at the other four tail end points, the positions of the other four end points are calculated, and the end points of the middle four welding seams and the other four end points are respectively connected to obtain an actual welding track.

Further, the motion control strategy comprises a robot external shaft form, a robot coordinate system direction, a robot travel range calibration and a robot motion speed; the welding process strategy comprises welding current, welding speed, an arc swinging mode, a welding power supply working mode, a welding seam offset mode and a welding seam offset distance.

In a second aspect, the present application also provides a steel structural member welding system based on robot welding, comprising:

a data acquisition module configured to: obtaining a structural model of a steel structural member;

a planning module configured to: planning locating and welding tracks according to the structural model; determining welding seam information to be welded from the structural model; planning a motion trail in a preset motion control strategy, a locating process strategy and a welding process strategy according to the structural model and the welding seam information;

a control module configured to: and controlling the robot to weld the steel structural member according to the planned locating and welding track.

Compared with the prior art, the application has the beneficial effects that:

1. firstly, constructing a structural model of a steel structural member; then, planning locating and welding tracks according to the structural model; specifically, determining weld information to be welded from a structural model; planning a motion trail in a preset motion control strategy, a locating process strategy and a welding process strategy according to the structural model and the welding seam information; finally, controlling the robot to weld the steel structural member according to the planned locating and welding track; by means of the structural model and according to the structural model and the welding seam information, the motion trail is planned in a preset motion control strategy, a locating process strategy and a welding process strategy, dependence on a machine vision technology is reduced, an effective welding trail is obtained, and the working stability of the whole welding process is improved;

2. according to the application, under three modes of conventional deviation, longitudinal deviation and dimensional deviation, the actual welding tracks corresponding to different numbers of fillet welds are determined, so that the effective welding tracks are obtained, and the working stability of the whole welding process is improved.

3. In the traditional parametric modeling method, part of the technology adopts the method that all parameters are given at one time to directly generate a model, so that the flexibility is poor, the method cannot be well used for building the model with a complex structure, and the built model has lower precision; in another part of the techniques, the most basic parameters are given, a simplest primitive is generated, and then a plurality of primitives are combined into a complex model, so that the workload is high. Aiming at the problems, when the model is built, various component node types are preset in offline programming software; selecting a preset node according to the node type of the actual component, inputting a corresponding size, and generating a component containing the node in software; the preset node types and input sizes are continuously selected according to the node types and the sizes of the actual components to be arranged and combined, so that a three-dimensional model of the actual components is obtained, and compared with the method for giving all parameters at one time, the method only aims at one model, the flexibility is greatly improved, complex models in different forms can be built, and the accuracy of the model is ensured; compared with the mode of giving one simple graphic element at a time, the method can give one more complex node at a time, reduces the workload and provides a reliable model foundation for the intelligent flow of welding the steel structural members by the robot.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification, illustrate and explain the embodiments and together with the description serve to explain the embodiments.

Fig. 1 is a flowchart of embodiment 1 of the present application.

Detailed Description

The application will be further described with reference to the drawings and examples.

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

Example 1:

at present, the flexible requirements of the steel structure industry are mostly met by adopting a machine vision mode in the industry, but the problems of high visual cost and poor stability are always obstructing the popularization of the solution, and an effective welding track cannot be obtained.

In view of the above problems, the present embodiment provides a method for welding a steel structural member based on robot welding, in which a structural model of the steel structural member is first constructed; then, planning locating and welding tracks according to the structural model; specifically, determining weld information to be welded from a structural model; planning a motion trail in a preset motion control strategy, a locating process strategy and a welding process strategy according to the structural model and the welding seam information; finally, controlling the robot to weld the steel structural member according to the planned locating and welding track; by means of the structural model and according to the structural model and the welding seam information, the motion trail is planned in a preset motion control strategy, a locating process strategy and a welding process strategy, dependence on a machine vision technology is reduced, an effective welding trail is obtained, and working stability of the whole welding process is improved.

Specifically, the embodiment reduces the dependence on the machine vision technology and improves the working stability of the whole process. Compared with the existing pure visual identification component or the visual+three-dimensional model, the embodiment provides three ways for obtaining the constructed model, and the specific obtaining method is different from the prior art, and compared with the existing line laser locating or three-dimensional visual locating mode, the embodiment adopts the method for generating the touch locating track by offline programming to solve the stability problem of visual locating; the method specifically comprises the following steps:

s1, obtaining a structural model of a steel structural member;

s2, planning locating and welding tracks according to the structural model;

and S3, executing actions by sending control codes to the robot or connecting the robot control API.

In step S1, optionally, when the structural model is obtained, the structural model may be derived after modeling by using three-dimensional software, and then be imported into offline programming software; or, carrying out integral photographing on the component to obtain an integral point cloud model of the component; and the latter, manually inputting the node size according to the preset node type, and parameterizing to build a component model.

The method comprises the steps of modeling through other three-dimensional software, exporting a model, importing the model into offline programming software, and adopting different methods according to different modeling software, wherein the optional method is as follows:

using tekla modeling, the model data in the tekla needs to be converted into data acceptable by offline programming software by using a tekla plug-in for secondary development, and the data comprises three-dimensional model information and weld position information;

alternatively, using machine industry engineering software modeling, such as SolidWorks, UG and proE, etc., the stp format model is directly exported into the offline programming software, and this data contains only three-dimensional model information.

The method comprises the steps of integrally photographing a component to obtain an integral point cloud model, fixing a camera on a ground rail in an out-of-hand mode, arranging the camera at a position right above a workpiece, enabling the camera to face the workpiece, and obtaining the integral point cloud in a line laser scanning or structured light multi-point photographing mode.

The parameterization building mode of the component model is to preset the component node type in offline programming software. Only the operator is required to select a preset node according to the node type of the actual component and input the corresponding size, and a component containing the node is generated in the software. The preset node type input sizes are continuously selected for arrangement and combination according to the node types and the sizes of the actual components, and a three-dimensional model of the actual components can be obtained rapidly.

For example, a typical steel column member often includes a column foot, ribs, brackets, connection plates, and the like. The dimensions of the steel column body, such as flange plate width, web width, flange plate thickness, web thickness, fillet size and steel column length of the H-section steel, can be input first, thus creating a steel column; selecting preset column foot nodes, inputting the position size and the shape size of a column foot, such as the length, the width and the thickness of a column foot at one end of a steel column, the number of triangular rib plates on the column foot, the spacing of the triangular rib plates, the length width chamfer size and the thickness of the triangular rib plates, so that a column foot is established on the steel column; selecting preset rib plate nodes, inputting the position size and the shape size of the rib plates, such as the distance between the rib plates and one end of a steel column, the height of the rib plates, the thickness of the rib plates and the size of rib plate chamfers, so that a rib plate is established on the steel column, and generally, a plurality of rib plates exist in one member, and the shape size of the rib plates can be copied to change the position size only so as to realize rapid addition of the plurality of rib plates; selecting preset bracket nodes, inputting the position size and the shape size of the bracket, for example, the distance between the bracket and one end of a steel column, the length width of the bracket or the inclination of the bracket and the plate thickness size of the outer contour of the bracket are simultaneously arranged on one side surface or two side surfaces of the steel column, and a plurality of rib plates are arranged in the bracket, so that one bracket or a pair of brackets are obtained; the preset connecting plate nodes are selected, the position size and the shape size of the connecting plate are input, for example, the distance between the connecting plate and one end of a steel column, the distance between the connecting plate and the edge of the steel column, the width of the connecting plate and the thickness of the connecting plate are selected, a plurality of connecting plates are arranged in one component generally, the shape size of the connecting plate can be copied, and only the position size is changed, so that the rapid addition of the plurality of connecting plates is realized.

S2, according to the structural model planning locating and welding track, firstly, a welding line to be welded is found out from the structural model, wherein if the structural model is derived from tekla or parameterized modeling of software, the welding line information is carried, and if the structural model is derived from other three-dimensional software or a point cloud model obtained by visual photographing, the welding line is judged by a deep learning method, and then whether the welding line information is correct or not is manually confirmed. And planning a motion track according to the preset motion control strategy, the locating process strategy and the welding process strategy from the model information and the weld joint information, wherein the locating process strategy is the most important, a touch locating mode is adopted, and the software automatically gives locating points, locating directions and locating points according to the node types.

The motion control strategy mainly comprises the form of an external shaft of the robot, the direction of a coordinate system of the robot, the calibration of the stroke range of the robot and the motion speed of the robot. The external shaft forms of the robot comprise a single-shaft ground rail type, a single-shaft suspension type, a single-shaft gantry type, a two-shaft suspension type, a two-shaft gantry type and a three-shaft gantry type.

The welding process strategy mainly comprises welding current, welding speed, an arc swinging mode, a welding power supply working mode, a welding seam offset mode and a welding seam offset distance.

The locating process strategy mainly comprises the steps of selecting one or more component pairing deviation forms according to the actual situation of the site and different phenomena of different field pairing precision, wherein the deviation forms comprise conventional deviation, longitudinal deviation and dimensional deviation, and the three forms are as follows:

aiming at a general working condition, a conventional deviation locating strategy assumes that the perpendicularity of the workpiece group meets the welding requirement, and locating compensation is not needed; and assuming that the dimensional accuracy of the workpiece meets the welding requirement, no locating compensation is needed. Therefore, the following locating mode is adopted:

for a double-sided fillet weld vertical to the component, only one weld is included, the position of the end point can be calculated by only making three locating points in the three directions of XYZ at one end of the weld, and then the actual welding track can be obtained by automatically extending to the other end according to the length of the weld in the model.

For a three-sided fillet weld vertical to the component, three welding lines are included, but all the three welding lines are attributed to one point, so long as three locating points are made in three directions of XYZ at the point where the three welding lines intersect, the intersecting position of the three welding lines can be calculated, and then the actual welding track can be obtained by extending from the end point to the tail end of the three welding lines according to the length of the welding lines in the model.

The four-side fillet weld vertical to the component comprises five welding lines, wherein two three-side intersection points pass through XYZ three directions at the two intersection points, three searching points are respectively carried out, two end points of one welding line can be calculated, and then the two end points extend to the tail ends of the other four welding lines according to the length of the welding line in the model, so that the actual welding track is obtained.

For a pentagonal weld perpendicular to the component, eight welds are included, four of the three-sided intersections pass through three directions of XYZ at the four intersections, three seeking points are respectively made, two end points of the four welds can be calculated, and then the actual welding track can be obtained by extending from the two end points to the tail ends of the other four welds according to the length of the welds in the model.

The longitudinal deviation locating strategy aims at the working conditions of high assembly precision and low material deformation, and the workpiece assembly perpendicularity is assumed to meet the welding requirement without locating compensation; assuming that the dimensional accuracy of the workpiece meets the welding requirement, locating compensation is not needed; the base material size uniformity is high assuming that the work piece is not bent. Therefore, the mode of reducing the locating points on the basis of the conventional deviation locating strategy is adopted, each locating point in the conventional deviation locating needs to find three directions of XYZ, the longitudinal deviation only finds the X direction, and the Y Z direction default precision meets the welding requirement.

The dimension deviation locating strategy aims at the working conditions of poor assembly precision and large material deformation, and the locating compensation is needed under the assumption that all positions of a workpiece have problems. Therefore, the following locating mode is adopted:

for a two-sided fillet weld, only one weld is included, three locating points are made at one end of the weld in the three directions of XYZ, the position of the end point can be calculated, then the two ends extend to the other end according to the length of the weld in the model, the position of the other end can be calculated by making three locating points at the XYZ direction of the other end, and the two ends are connected to form an actual welding track.

The three welding lines are all attributed to one point, three locating points are made in the XYZ three directions at the crossing points of the three welding lines, the crossing positions of the three welding lines can be calculated, then the other three welding lines extend to the tail end, three locating points are respectively made in the XYZ directions of the other three tail end points, the positions of the other three tail ends can be calculated, and the crossing points and the other three tail ends are respectively connected, so that an actual welding track is obtained.

The four-side fillet weld comprises five welding lines, wherein two three-side intersecting points are respectively provided with three locating points in the XYZ three directions at the two intersecting points, two end points of one welding line can be calculated, then the other four welding lines extend to the tail ends, three locating points are respectively provided with the other four end points in the XYZ directions, the positions of the other four end points can be calculated, and the two end points and the other four end points of the middle welding line are respectively connected, so that an actual welding track can be obtained.

The five-sided fillet weld comprises eight welding seams, wherein four three-sided intersecting points are respectively provided with three locating points in the XYZ three directions at the four intersecting points, two end points of the four welding seams can be calculated, then the four welding seams extend to the tail ends, three locating points are respectively provided with the other four end points in the XYZ directions, the positions of the other four end points can be calculated, and the end points of the middle four welding seams and the other four end points are respectively connected, so that an actual welding track is obtained.

And S3, executing actions by sending control codes to the robot or connecting the robot control API.

Optionally, a plurality of robot post-processing logics are built in the software, control code instructions adapting to the brand of robots can be generated according to the planned tracks, the robot demonstrator is connected to the robot demonstrator through network communication, or code files are copied to the robot demonstrator through a USB flash disk to be executed.

The robot supporting API of the individual brands can directly control the robot, and the robot action can be directly controlled on the upper computer through offline programming software without additionally operating on a demonstrator.

Example 2:

the embodiment provides a steel structural member welding system based on robot welding, comprising:

a data acquisition module configured to: obtaining a structural model of a steel structural member;

a planning module configured to: planning locating and welding tracks according to the structural model; determining welding seam information to be welded from the structural model; planning a motion trail in a preset motion control strategy, a locating process strategy and a welding process strategy according to the structural model and the welding seam information;

a control module configured to: and controlling the robot to weld the steel structural member according to the planned locating and welding track.

The working method of the system is the same as the welding method of the steel structural member based on the robot welding in embodiment 1, and will not be repeated here.

The above description is only a preferred embodiment of the present embodiment, and is not intended to limit the present embodiment, and various modifications and variations can be made to the present embodiment by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment should be included in the protection scope of the present embodiment.

Claims (10)

1. A method for welding a steel structural member based on robot welding, comprising:

obtaining a structural model of a steel structural member;

planning locating and welding tracks according to the structural model; specifically, determining weld information to be welded from the structural model; planning a motion trail in a preset motion control strategy, a locating process strategy and a welding process strategy according to the structural model and the welding seam information;

and controlling the robot to weld the steel structural member according to the planned locating and welding track.

2. The welding method for steel structural members based on robot welding according to claim 1, wherein the steel structural members are integrally photographed to obtain an integral point cloud model of the members.

3. A method for welding steel structural members based on robot welding according to claim 1, characterized in that various member node types are preset in off-line programming software; selecting a preset node according to the node type of the actual component, inputting a corresponding size, and generating a component containing the node in software; and continuously selecting preset node types and input sizes according to the node types and the sizes of the actual components to perform permutation and combination, so as to obtain a three-dimensional model of the actual components.

4. A method of welding a steel structural member based on robot welding according to claim 3, wherein the dimensions of steel column feet, rib plates, brackets and connecting plates in the steel structural member are obtained; establishing a steel column model according to the flange plate width, the web plate width, the flange plate thickness, the web plate thickness, the fillet size and the steel column length of the steel column; selecting preset column foot nodes, and obtaining a column foot model on the steel column according to the length, width and thickness of the column foot at one end of the steel column, the number of triangular rib plates on the column foot, the distance between the triangular rib plates, the length of the triangular rib plates, the width of the triangular rib plates, the chamfer angle of the triangular rib plates and the thickness of the triangular rib plates; selecting preset rib plate nodes, obtaining a rib plate model on the steel column according to the distance of the rib plate at one end of the steel column, the height of the rib plate, the thickness of the rib plate and the chamfer size of the rib plate, copying the shape size of the rib plate, and only changing the position size to obtain a plurality of rib plate models on the steel column; selecting preset bracket nodes, and obtaining a bracket model according to the distance of the bracket at one end of the steel column, the length width and the inclination of the bracket, the plate thickness dimension of the outer contour, and the positions and the plate thickness dimension of a plurality of rib plates in the bracket; and selecting preset connecting plate nodes, obtaining a connecting plate model according to the distance between the connecting plate and one end of the steel column, the distance between the connecting plate and the edge of the steel column, the width of the connecting plate and the thickness of the connecting plate, copying the shape and the size of the connecting plate, and only changing the position and the size to obtain a plurality of connecting plate models.

5. The welding method for the steel structural members based on the robot welding according to claim 1, wherein the locating process strategy comprises the steps of selecting one or more member group deviation forms according to the phenomena of different field group pair precision according to the field actual situation; the group deviation forms include a normal deviation, a longitudinal deviation, and a dimensional deviation.

6. The welding method of the steel structural member based on the robot welding according to claim 5, wherein when the conventional deviation locating is adopted, three locating points are made in three directions of XYZ at one end of a welding line, the position of an endpoint is calculated, and then the welding line automatically extends to the other end according to the length of the welding line, so that an actual welding track is obtained;

for a double-sided fillet weld vertical to the component, three locating points are made at one end of the weld in three directions of XYZ, the position of the end point is calculated, and then the welding points automatically extend to the other end according to the length of the weld, so that an actual welding track is obtained; three locating points are made on a three-face fillet weld vertical to the component in the three-face welding line crossing point in the three directions of XYZ, the crossing position of the three-face welding line is calculated, and then the three-face fillet weld extends from the crossing position to the tail end of the three-face welding line according to the length of the welding line, so that an actual welding track is obtained; for a four-side fillet weld vertical to the component, three searching points are respectively made in the three directions of XYZ at two intersecting points, two end points of one welding line are calculated, and then the two end points extend to the tail ends of the other four welding lines according to the length of the welding line, so that an actual welding track is obtained; and (3) carrying out three searching points on a pentagonal welding line perpendicular to the component at four intersecting points in three directions of XYZ, calculating two end points of the four welding lines, and extending from the two end points to the tail ends of the other four welding lines according to the length of the welding lines to obtain an actual welding track.

7. The welding method for steel structural members based on robot welding according to claim 6, wherein when adopting a longitudinal deviation locating strategy, locating points are reduced on the basis of a conventional deviation locating strategy.

8. The welding method of the steel structural member based on the robot welding according to claim 5, wherein when adopting a size deviation locating strategy, three locating points are made in three directions of XYZ at one end of a welding line to calculate the position of an end point, then the welding line extends to the other end according to the length of the welding line, three locating points are made in the XYZ direction of the other end to calculate the position of the other end point, and the two end points are connected to obtain an actual welding track; for a two-sided fillet weld, three locating points are made in three directions of XYZ at one end of the weld, the position of an end point is calculated, then the welding points extend to the other end according to the length of the weld, three locating points are made in the XYZ direction of the other end, the position of the other end point is calculated, and the two end points are connected to obtain an actual welding track; for a three-sided angle weld, three locating points are made in the three directions of XYZ at the crossing points of the three weld, the crossing positions of the three weld are calculated, then the other three weld extends to the tail end, three locating points are respectively made in the XYZ directions of the other three tail end points, the positions of the other three end points are calculated, and the crossing positions and the other three end points are respectively connected to obtain an actual welding track; for one four-side fillet weld, three locating points are respectively formed in the two intersecting points in the XYZ directions, two end points of one weld are calculated, then the other four welds extend to the tail end, three locating points are respectively formed in the XYZ directions of the other four tail end points, the positions of the other four end points are calculated, and the two end points and the other four end points of the middle weld are respectively connected to obtain an actual welding track; for a pentagonal welding seam, three locating points are respectively made in the directions of XYZ at four intersecting points, two end points of four welding seams are calculated, then the four welding seams extend to the tail ends, three locating points are respectively made in the directions of XYZ at the other four tail end points, the positions of the other four end points are calculated, and the end points of the middle four welding seams and the other four end points are respectively connected to obtain an actual welding track.

9. A method of welding steel structural members based on robotic welding as claimed in claim 1, wherein said motion control strategy includes robot external axis form, robot coordinate system orientation, robot range of travel calibration and robot motion speed; the welding process strategy comprises welding current, welding speed, an arc swinging mode, a welding power supply working mode, a welding seam offset mode and a welding seam offset distance.

10. A steel structural member welding system based on robot welding, comprising:

a data acquisition module configured to: obtaining a structural model of a steel structural member;

a planning module configured to: planning locating and welding tracks according to the structural model; determining welding seam information to be welded from the structural model; planning a motion trail in a preset motion control strategy, a locating process strategy and a welding process strategy according to the structural model and the welding seam information;

a control module configured to: and controlling the robot to weld the steel structural member according to the planned locating and welding track.