CN115041701A

CN115041701A - Manufacturing method and system for multi-directional steel node bent pipe branch based on electric arc additive

Info

Publication number: CN115041701A
Application number: CN202210797543.5A
Authority: CN
Inventors: 陈胜元; 余圣甫; 汪能; 余振宇
Original assignee: Hubei Honglu Steel Structure Co Ltd
Current assignee: Hubei Honglu Steel Structure Co Ltd
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2022-09-13
Anticipated expiration: 2042-07-08
Also published as: CN115041701B

Abstract

The invention relates to a manufacturing method of a multidirectional steel node elbow branch based on electric arc additive manufacturing, which comprises the following steps: acquiring a digital model of the bent pipe part; acquiring a central axis of a pipeline based on a digital model of a bent pipe part, and determining a tangent slope curve of the central axis of the pipeline; acquiring an electric arc additive manufacturing process parameter library; performing digital-to-analog slicing to obtain a plurality of sliced layers; for each sliced layer, acquiring a thickness change curve of the sliced layer and a path position of a welding bead in the sliced layer; acquiring an arc process parameter change curve corresponding to the corresponding welding bead based on a welding bead high-melting-temperature change curve and an arc additive manufacturing process parameter library; printing the current slice layer based on the arc process parameter change curve corresponding to the weld bead and the weld bead position in the slice layer; the manufacturing method and the system realize automatic slicing of the multi-directional steel node bent pipe area through the extracted central axis of the pipeline of the bent pipe part.

Description

Manufacturing method and system for multi-directional steel node bent pipe branch based on electric arc additive

Technical Field

The invention relates to the technical field of additive manufacturing, in particular to a manufacturing method and system of an arc-based additive multidirectional steel node bent pipe branch.

Background

The multi-directional steel node is generally composed of a plurality of circular pipe pieces with different orientations, different sizes and different thicknesses, and the pipe pieces are connected with one another in an intersecting and intersecting mode and can be used for bearing forces from different directions and changing the bearing direction of the forces in the structure. The multidirectional steel node is generally positioned in a key part of a steel structure and is a key component in a modern large complex steel structure. As the multidirectional steel nodes in different buildings are usually designed differently and belong to personalized products, and the traditional casting method is time-consuming, labor-consuming, high in rejection rate and high in cost, the electric arc additive manufacturing technology becomes one of the main manufacturing means of the existing multidirectional steel nodes.

However, the multi-directional steel node comprises a plurality of bent pipe branch pipes, and the bent pipe branch pipes have different space curves and complicated shapes, so that the bent pipe branch pipes are difficult to form by a conventional plane slicing or printing strategy. Therefore, for the elbow part, the current common method is to manually divide the part into a straight line section and a bent section, a plane slicing mode is adopted in the straight line section, and the result of the plane slicing is manually corrected in the bent section, so that the elbow branch printing in the multi-directional steel node is realized. However, the manual correction of the slicing result is not repeatable for different parts, and the molding quality of the printed product after correction is greatly affected by the operator, and the printing process is difficult to control.

Disclosure of Invention

The invention aims to provide a manufacturing method and a system of a multi-directional steel node bent pipe branch based on electric arc additive, and the manufacturing method and the system realize automatic slicing of a multi-directional steel node bent pipe area through the extracted central axis of a pipe of a bent pipe part.

The specific scheme of the invention is as follows: a method of manufacturing an arc-based additive multi-directional steel node elbow branch, the method comprising:

acquiring a digital model of the bent pipe part;

acquiring a central axis of the pipeline based on the digital model of the elbow part, and determining a tangent slope curve of the central axis of the pipeline;

acquiring an electric arc additive manufacturing process parameter library, wherein the process parameter library comprises the melting height of workpieces under different electric arc process parameters, and determining an upper limit value and a lower limit value of the melting height in the process parameter library;

performing digital-analog slicing on the basis of a tangent slope curve of the central axis of the pipeline to obtain a plurality of slice layers, wherein each slice layer is formed by overlapping a plurality of welding seams, the fusion height of each welding seam is not completely consistent, and the thickness of each slice layer is between an upper limit value and a lower limit value of the fusion height;

for each sliced layer, acquiring a thickness change curve of the sliced layer and path positions of weld beads in the sliced layer, and determining a melting temperature change curve of each weld bead based on the thickness change curve of the sliced layer and the path positions of the weld beads;

acquiring an arc process parameter change curve corresponding to the welding bead based on the welding bead melting height change curve and the arc additive manufacturing process parameter library;

and printing the current slicing layer based on the arc process parameter change curve corresponding to the welding bead and the welding bead position in the slicing layer.

Further, the method for acquiring the central axis of the digital model of the elbow part comprises the following steps: and acquiring the central axis based on modeling information in the elbow part digital model.

Further, the obtaining of the central axis of the numerical model of the elbow part in the invention includes: obtaining the central axis based on an image processing algorithm; the image processing algorithm comprises gray processing, binarization operation and a center line extraction algorithm, the gray processing and the binarization operation can obtain the minimum envelope surface of the bent pipe, the center line extraction algorithm can fit a circular profile surface based on the minimum envelope surface of the bent pipe, and the central axis is obtained based on the circular profile surface extraction.

Further, the present invention performs digital-to-analog slicing based on a tangent slope curve of a central axis of the pipeline to obtain a plurality of sliced layers, and further includes: acquiring a tangent slope change curve corresponding to the tangent slope curve; determining a first preset threshold value of slope change; when the tangent slope change curve is larger than or equal to the first preset threshold, changing the pose of the robot/positioner of the current slicing layer, and performing digital-analog slicing based on the tangent direction of the central axis after the pose is changed; and when the change curve of the tangent slope is smaller than the first preset threshold value, performing digital-analog slicing based on the tangent direction of the central axis of the pipeline.

Further, in the present invention, the performing digital-analog slicing based on the tangential direction of the central axis of the pipeline further includes:

and when the thickness of the part of the digital analogy after slicing exceeds the upper limit value or the lower limit value of the melting height, correcting slices of a plurality of adjacent layers of the slicing layer, and averaging the exceeding/missing parts of the part of the digital analogy into the adjacent layers to ensure that the thickness of the slice of the whole digital analogy meets the requirement.

Further, the electric arc process parameters in the invention comprise one or more of voltage, current, welding speed, pulse frequency, base current and peak current.

A system for manufacturing an arc additive-based multi-directional steel node elbow branch, the system comprising:

the part digital-analog obtaining module is used for obtaining a part digital-analog of the bent pipe;

the tangent slope curve determining module is used for acquiring a central axis of the pipeline based on the digital model of the elbow part and determining a tangent slope curve of the central axis of the pipeline;

the system comprises a process parameter library acquisition module, a control module and a control module, wherein the process parameter library acquisition module is used for acquiring an electric arc additive manufacturing process parameter library, the process parameter library comprises the melting height of workpieces under different electric arc process parameters, and an upper limit value and a lower limit value of the melting height are determined in the process parameter library;

the slicing layer obtaining module is used for carrying out digital-analog slicing on the basis of a tangent slope curve of the central axis of the pipeline to obtain a plurality of slicing layers, wherein each slicing layer is formed by overlapping a plurality of welding seams, the melting height of each welding seam is not completely consistent, and the thickness of each slicing layer is between an upper limit value and a lower limit value of the melting height;

the slicing layer processing module is used for acquiring a thickness change curve of each slicing layer and a path position of a welding bead in the slicing layer for each slicing layer, and determining a melting temperature change curve of each welding bead based on the thickness change curve of each slicing layer and the path position of the welding bead; acquiring an arc process parameter change curve corresponding to the corresponding welding bead based on the welding bead high-melting-height change curve and the arc additive manufacturing process parameter library; and printing the current slicing layer based on the arc process parameter change curve corresponding to the welding bead and the welding bead position in the slicing layer.

A system for manufacturing an arc additive based multi-directional steel node elbow branch, the system comprising a processor configured to perform any one of the arc additive based multi-directional steel node elbow branch manufacturing methods.

According to the method, the automatic slicing of the multi-directional steel node bent pipe area is realized through the extracted central axis of the pipeline of the bent pipe part, the mode of correcting the slicing result has repeatability, the molding quality of the printed part after correction is guaranteed, the printing process can be controlled, and the method has good practical application and popularization values.

Drawings

The specification will further describe exemplary embodiments, which will be described in detail by way of accompanying drawings. These embodiments are not intended to be limiting, and in these embodiments like numerals are used to indicate like structures, wherein:

FIG. 1 is a system block diagram of an exemplary arc additive based multi-directional steel node elbow branch manufacturing system according to embodiments of the present invention;

FIG. 2 is a schematic flow diagram of a method of manufacturing an arc additive based multi-directional steel node elbow branch according to an embodiment of the invention;

FIG. 3 is a schematic flow chart of a method for performing digital-to-analog slicing based on a tangent slope curve of a central axis of a pipeline according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a multi-directional steel node part digifax shown in the embodiment of the invention;

FIGS. 5-1 and 5-2 are schematic diagrams showing slope curves corresponding to elbow branches in the digifax of the multi-directional steel node part shown in FIG. 4;

FIG. 6 is a schematic diagram of the minimum circumcircle of the pipeline and the determination of the position of the central axis according to the embodiment of the present invention;

FIG. 7 is a schematic illustration of a planar slice shown in an embodiment of the present invention;

FIG. 8 is a schematic diagram illustrating adaptive slice-angle changes based on the slope of a leg of an elbow according to an embodiment of the invention;

FIG. 9 is a schematic diagram illustrating adaptive slice-level angle changes based on the slope of the elbow branch after pose changes, according to an embodiment of the invention;

fig. 10 is a schematic view of a weld bead cross section shown in accordance with an embodiment of the present invention.

Detailed Description

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only examples or embodiments of the invention, and that for a person skilled in the art the invention can be applied to other similar contexts without inventive effort on the basis of these drawings. Unless otherwise apparent from the context, or otherwise indicated, like reference numbers in the figures refer to the same structure or operation.

It should be understood that "system", "device", "unit" and/or "module" as used in this specification is a method for distinguishing different components, elements, parts or assemblies at different levels. However, other words may be substituted by other expressions if they accomplish the same purpose.

As used in this specification and the appended claims, the terms "a," "an," "the," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

Flow charts are used in this description to illustrate operations performed by a system according to embodiments of the present description. It should be understood that the preceding or following operations are not necessarily performed in the exact order in which they are performed. Rather, the various steps may be processed in reverse order or simultaneously. Meanwhile, other operations may be added to the processes, or a certain step or several steps of operations may be removed from the processes.

Fig. 1 is a system block diagram of an exemplary arc additive based multi-directional steel node elbow branch manufacturing system, according to an embodiment of the present invention.

As shown in fig. 1, the system 100 may include: a part digital-to-analog obtaining module 110, a tangent slope curve determining module 120, a process parameter library obtaining module 130, a slice layer obtaining module 140, and a slice layer processing module 150, wherein:

a part digital-analog obtaining module 110, configured to obtain a bent pipe part digital analog;

a tangent slope curve determining module 120, configured to obtain a central axis of the pipeline based on the elbow part digital model, and determine a tangent slope curve of the central axis of the pipeline;

a process parameter library obtaining module 130, configured to obtain an arc additive manufacturing process parameter library, where the process parameter library includes melting heights of workpieces under different arc process parameters, and an upper limit value and a lower limit value of the melting heights are determined in the process parameter library;

the slicing layer obtaining module 140 is configured to perform digital-to-analog slicing on the basis of a tangent slope curve of the central axis of the pipeline to obtain a plurality of slicing layers, where each slicing layer is formed by overlapping a plurality of welding seams, the melting height of each welding seam is not completely consistent, and the thickness of each slicing layer is between an upper limit value and a lower limit value of the melting height;

the slicing layer processing module 150 is configured to acquire, for each slicing layer, a thickness variation curve of the slicing layer and a path position of a weld bead in the slicing layer, and determine a melting temperature variation curve of each weld bead based on the thickness variation curve of the slicing layer and the path position of the weld bead; acquiring an arc process parameter change curve corresponding to the welding bead based on the welding bead melting height change curve and the arc additive manufacturing process parameter library; and printing the current slicing layer based on the arc process parameter change curve corresponding to the welding bead and the welding bead position in the slicing layer.

Further, the tangent slope curve determining module 120 is configured to obtain the central axis based on modeling information in the elbow part digifax.

Further, the tangent slope curve determining module 120 is further configured to obtain the central axis based on an image processing algorithm; the image processing algorithm comprises gray processing, binarization operation and a center line extraction algorithm, the gray processing and the binarization operation can obtain the minimum envelope surface of the bent pipe, the center line extraction algorithm can fit a circular profile surface based on the minimum envelope surface of the bent pipe, and the central axis is obtained based on the circular profile surface extraction.

Further, the slice layer obtaining module 140 is further configured to obtain a tangent slope change curve corresponding to the tangent slope curve; determining a first preset threshold value of slope change; when the tangent slope change curve is larger than or equal to the first preset threshold, changing the pose of the robot/positioner of the current slicing layer, and performing digital-analog slicing based on the tangent direction of the central axis after the pose is changed; and when the change curve of the tangent slope is smaller than the first preset threshold value, performing digital-analog slicing based on the tangent direction of the central axis of the pipeline.

Further, in the present invention, the slice layer obtaining module 140 is further configured to, when the thickness of the part of the digifax after being sliced exceeds the upper limit value or the lower limit value of the melting height, correct slices of several adjacent layers of the slice layer, and average the exceeding/missing part of the digifax into the several adjacent layers, so that the thickness of the slice of the whole digifax meets the requirement.

It should be appreciated that the system and its modules in one or more implementations of the present description may be implemented in a variety of ways. For example, in some embodiments, the system and its modules may be implemented in hardware, software, or a combination of software and hardware. Wherein the hardware portion may be implemented using dedicated logic; the software portions may be stored in a memory for execution by a suitable instruction execution system, such as a microprocessor or specially designed hardware. Those skilled in the art will appreciate that the methods and systems described above may be implemented using computer executable instructions and/or embodied in processor control code, such code being provided, for example, on a carrier medium such as a diskette, CD-or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The system and its modules in this specification may be implemented not only by hardware circuits such as very large scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., but also by software executed by various types of processors, for example, or by a combination of the above hardware circuits and software (e.g., firmware).

It should be noted that the above description of the processing device and its modules is merely for convenience of description and is not intended to limit the present description to the scope of the illustrated embodiments. It will be appreciated by those skilled in the art that, given the teachings of the present system, any combination of modules or sub-system configurations may be used to connect to other modules without departing from such teachings.

Fig. 2 is a schematic flow diagram of a method of manufacturing an arc additive based multi-directional steel node elbow branch according to an embodiment of the invention. In some embodiments, the method 200 may further be performed by the system 100.

And step 210, acquiring a multi-directional steel node bent pipe branch digital analog.

In some embodiments, step 210 may be performed by part digital-to-analog acquisition module 110.

As shown in fig. 4, which is a part digifax of a typical multi-directional steel node, in the drawing, the

branch pipes

410 and 420 are typical elbow branches, 430 is a main pipe of the multi-directional steel node, and 440 is a intersecting region of the multi-directional steel node. It should be noted that the multi-directional steel node part digifax in fig. 4 is only used as an example and is not meant to limit the present invention. For example, there may be other numbers of elbow branches in a multidirectional steel node part digifax, such as 2, 3, 4, 6, 8 …, etc. For another example, the pipe elements in the digifax of the multi-directional steel node part may be formed by combining circular pipes, square pipes, irregular curved pipes, and the like with different diameters, and the description herein is not limited.

And step 220, acquiring a central axis of the pipeline based on the digital model of the elbow part, and determining a tangent slope curve of the central axis of the pipeline.

In some embodiments, step 220 may be performed by the tangent slope curve determination module 120.

In some embodiments, tangent slope curve determination module 120 may obtain the corresponding pipe diameter and pipe axis position directly based on modeling information in the printed part data model. For example, a digital model of a to-be-processed printing part is modeled and drawn by using three-dimensional drawing software such as UG, SOLIDWORKS, CATIA, etc., and modeling driving information is retained in the digital model, the tangent slope curve determining module 120 may directly obtain the diameter of the pipe fitting and the position of the axial line in the pipe fitting based on the modeling driving information. The modeling driving information refers to original information required for drawing a digital model, which is reserved in the modeling process, for example, the drawing of a pipe in three-dimensional software is driven and generated by information such as spline curves and modeling sketches, and then the elements such as the spline curves and the modeling sketches can be called as the modeling driving information. Specifically, the centerline information (e.g., centerline 411 and centerline 421) of the elbow branch is retained in the digifax of the multidirectional steel node shown in fig. 4.

In some embodiments, the cross-sectional shape of the elbow branches may be an irregular arbitrary shape. Specifically, an irregular pipe is shown in fig. 6. In the figure, 610 represents a pipe with an irregular section, 620 represents the smallest circumscribed cylinder tangent to the

pipe

610, 640 represents spline curve information left in the original modeling process, 630 represents the pipe centerline position, and 650 diagonally shaded areas represent sketch information required to draw a numerical model. It is apparent that the pipe 610 shown in fig. 6 is drawn by spline curve 640 through sketch 650. In this scenario embodiment, the tangent slope curve determination module 120 may directly read the modeling driving information (shaded region 650 and spline curve 640) based on the digital-analog, and then directly obtain the sketch and the axis position in the pipe based on the modeling driving information. For example, the tangent slope curve determination module 120 may obtain the size of the smallest circumscribed cylinder (e.g., the graph 620) from the sketch and obtain the position relationship between the spline curve 640 and the circumscribed circle center line 630, so as to obtain the position of the circumscribed circle center line 630 (i.e., the central axis of the pipe).

In some embodiments, the tangent slope curve determination module 120 may obtain the corresponding tubular diameter and tubular axis position based on an image processing algorithm. The image processing algorithm may include, but is not limited to, one or more of a series of algorithms including gray scale processing, binarization operation, and centerline extraction algorithm. Specifically, the grayscale processing and/or binarization operation may extract an outer surface of the pipe (that is, the pipe 610 is obtained), the center line extraction algorithm may determine a minimum circumscribed circular profile (that is, the minimum circumscribed cylinder 620 is obtained) based on the outer surface of the pipe (that is, the pipe 610 is obtained), and then extract a central axis of the pipe (that is, the central axis 630 is obtained) and a diameter of the pipe corresponding to the central axis based on the minimum circumscribed circular profile.

Further, the tangent slope curve determination module 120 may determine a tangent slope curve of the central line axis based on the obtained central line axis. It will be appreciated that the central axis of the conduit may be a straight line or a two-dimensional curve or a three-dimensional curve reflecting the orientation of the elbow branch in space. Therefore, the slope curve of the tangent to the central axis of the pipe may be a constant value (with a constant slope of the bend), or may be an arbitrary curve or a polygonal line. Fig. 5-1 shows a tangential slope curve corresponding to the central axis of the elbow leg 410, and fig. 5-2 shows a tangential slope curve corresponding to the central axis of the elbow leg 420.

And step 230, acquiring an electric arc additive manufacturing process parameter library.

In some embodiments, step 230 may be performed by the process parameter library acquisition module 130.

The electric arc additive manufacturing process parameter library comprises melting height and melting width data corresponding to various electric arc process parameters, wherein the electric arc process parameters comprise one or more of voltage, current, welding speed, pulse frequency, base value current and peak value current.

Further, the process parameter library obtaining module 130 determines an upper limit value and a lower limit value of the melting height based on the melting height information in the arc additive manufacturing process parameter library, so as to determine the maximum value and the minimum value of the slice thickness.

And 240, performing digital-to-analog slicing on the basis of the tangent slope curve of the central axis of the pipeline to obtain a plurality of sliced layers.

In some embodiments, step 240 may be performed by slice layer acquisition module 140.

It will be appreciated that the formed part is built up from N layers of sliced layers. In one or more embodiments of the present disclosure, each sliced layer may have a thickness that is completely uniform or not completely equal, but the upper and lower melting height limits determined in step 230 are between the upper and lower melting height limits regardless of the thickness of the sliced layer in a layer.

Due to the arc fuse additive manufacturing technology, direct forming of parts with certain inclination angles can be achieved (for example, direct forming can be achieved when the inclination angle is lower than 45 degrees). Therefore, in some embodiments of the present disclosure, when the slope of the central axis is lower than a certain value (e.g., when the slope of the central axis is lower than 1), the slice layer obtaining module 140 may directly perform plane slicing on the elbow branch, so as to obtain multiple slice layers. For example, if the tangent slope of the tangent slope curve shown in fig. 5-1 is always below 1, the corresponding elbow branch 410 can be sliced directly by planar slicing. A typical planar slicing method is shown in fig. 7, and the distribution of sliced layers is between the dotted lines. In an embodiment of the scenario, slices are sliced and layered along a plurality of parallel planes all the time, and then corresponding arc additive manufacturing paths and corresponding process parameters are generated based on the slicing results. It should be noted that, when the planar slicing method shown in fig. 7 is used for slicing, the thicknesses of the sliced layers may be uniform or nonuniform; the parameters of the arc additive process of the sliced layer and the sliced layer can be consistent or inconsistent, and similar changes are still within the protection scope of the invention.

In some embodiments, when the thickness of the sliced part of the digifax exceeds the upper limit value or the lower limit value of the melt height, the slice layer obtaining module 140 further corrects slices of several adjacent layers of the slice layer, and averages the exceeding/missing parts of the part of the digifax into the several adjacent layers, so that the slice thickness of the whole digifax meets the requirement.

However, although the entire product can be printed when the slice layer obtaining module 140 directly performs slicing on the elbow branch by using a planar slicing method, the surface of the obtained metal product has a shape similar to the original model due to the thick layer in the arc additive manufacturing process, and the roughness is low and the manufacturing accuracy is poor.

In order to make the shape of the printed and molded part more fit the actual digital-analog, in one or more embodiments of the present invention, the slice layer obtaining module 140 may perform adaptive slice layer angle change based on the slope of the elbow branch, so that the slice layer fits the actual digital-analog as much as possible. As shown in fig. 8, specifically, the slice layer obtaining module 140 may perform digital-analog slicing based on a tangential direction of the central axis, the printing mechanism further obtains a corresponding digital-analog slicing result, and the arc additive manufacturing apparatus further performs direct printing of the slice layer.

In one or more arc additive manufacturing application scenarios involving the present invention, the inclination angle of the central axis of the elbow branch may exceed the limit angle that the arc fuse additive manufacturing technology can directly form. At the moment, because the metal wire or the metal strip can be melted into the liquid metal in the electric arc additive printing process, when the liquid metal is not solidified, the liquid metal tends to flow downwards under the action of gravity, so that the forming precision of a printed and formed part is poor or the printed and formed part can not be formed directly. In some embodiments, in order to improve the forming precision of the surface of the workpiece, the slice layer obtaining module 140 may obtain a tangent slope variation curve corresponding to the tangent slope curve; determining a first preset threshold value of slope change; when the tangent slope change curve is larger than or equal to the first preset threshold, changing the pose of the robot/positioner of the current slicing layer, and performing digital-analog slicing based on the tangent direction of the central axis after the pose is changed; and when the change curve of the tangent slope is smaller than the first preset threshold value, performing digital-analog slicing based on the tangent direction of the central axis of the pipeline.

Step 250 further includes substeps 251 through 259. In some embodiments, step 250 may be performed by sliced layer processing module 150.

And 251, acquiring a thickness change curve of the slice layer and path positions of weld beads in the slice layer, and determining a melting temperature change curve of each weld bead based on the thickness change curve of the slice layer and the path positions of the weld beads.

As can be seen from one or more embodiments of the present invention, the thickness of the obtained sliced layer is not completely uniform, and therefore, in order to meet the requirement of fusion height for different sliced layer positions, the variation curve of the process parameters in the current sliced layer needs to be determined. In one or more embodiments of the present description, the thickness variation curve may be obtained based on a sliced layer that has already been sliced. The thickness variation curve may be reflected in the form of a three-dimensional cloud representing thickness information for each point in the sliced layer. Further, the manner and direction of bead filling in the sliced layer are determined, and the melt height variation of each bead is determined based on the filling direction of the bead. A schematic view of a typical weld bead cross-sectional arrangement is shown in fig. 10. After the three-dimensional cloud image with the known thickness is obtained, a weld bead section (as shown in fig. 10) can be obtained, and the weld heights corresponding to the weld beads 1, 2, 3 and 4 are determined based on the weld bead section (as shown in fig. 10). Therefore, the melting temperature change curves corresponding to different welding beads can be easily obtained based on different welding bead sections.

It will be appreciated that since each bead is not of a regular cross-section, in one or more embodiments of the present description, the highest value of the top surface above the bead may be taken as the weld height of the bead at this location. In some embodiments, the mean value of the discrete top surface on the weld bead can also be used as the weld height of the weld bead at the present position. In still other embodiments, the centroid of the arc region may also be used as the location coordinate of the melt-up at the present location.

And 253, acquiring an arc process parameter change curve corresponding to the weld bead based on the weld height change curve of the weld bead and the arc additive manufacturing process parameter library.

The slice layer processing module 150 may further determine an arc process parameter variation curve corresponding to the weld bead based on the weld bead melting variation curve obtained in step 251 and the arc additive manufacturing process parameter library. Because the arc process parameter library comprises the arc process parameters corresponding to different melting heights, the corresponding process parameter curve can be determined based on the melting height value in the melting height change curve.

It is understood that the parameters affecting the arc fuse additive manufacturing fuse height include, but are not limited to, one or more of voltage, current, welding speed, pulse frequency, background current, and peak current. Therefore, in one or more embodiments of the present disclosure, the corresponding arc process parameter variation curve includes, but is not limited to, one or more of a voltage variation curve, an average current variation curve, a welding speed variation curve, a pulse frequency variation curve, a base current variation curve, a peak current variation curve, and the like.

Further, since the variation of the welding speed has a great influence on the melt width of the entire bead, the melt height fluctuates greatly at a constant weld bead overlapping amount. Therefore, in one or more embodiments of the present specification, the change value of the welding speed in the arc process parameter change curve should tend to be stable, and the welding height should be adaptively adjusted based on other parameters preferentially, and when the change of other parameters cannot meet the change requirement of the welding height adjustment, the welding height is corrected by fine adjustment of the welding speed.

And 259, printing the current slicing layer based on the electric arc process parameter change curve corresponding to the welding bead and the welding bead position in the slicing layer.

The slice layer processing module 150 may determine an arc process parameter based on a melting height corresponding to a weld bead, determine a process parameter variation curve based on the melting height variation curve, and perform additive manufacturing of a current slice layer based on the process parameter variation curve and a position of the weld bead.

FIG. 3 is a schematic flow chart diagram illustrating a method for digital-to-analog slicing based on a tangent slope curve of a centerline axis of a pipeline in accordance with some embodiments of the invention.

And step 310, acquiring a tangent slope change curve corresponding to the tangent slope curve.

Illustratively, the corresponding change curve of the slope of the tangent may be obtained based on the slope curves of the tangents as shown in fig. 5-1 and 5-2. It can be understood that the change rate of the tangent slope is reflected by the change curve of the tangent slope, and mainly represents the degree of the bending change of the elbow branch, and the faster the change rate of the tangent slope is, the faster the change of the bending angle of the elbow branch is, the lower the probability that the printing can be directly performed is.

Step 320, determining a first preset threshold of slope change, and determining whether the tangent slope change curve is greater than the first preset threshold.

The first predetermined threshold value may be a value obtained through a number of experiments and having manufacturability. In some embodiments, the first predetermined threshold may also be a value that is manually determined by a human technician. The description is not intended to be limiting.

And 330, when the change curve of the tangent slope is greater than or equal to the first preset threshold, changing the pose of the robot/position changer of the current slice layer, and performing digital-analog slicing based on the tangent direction of the central axis after the pose is changed.

The robot position posture comprises a welding gun posture and a positioner posture, but because the position of a welding gun is consistent with the orientation of the positioner in the welding process, when the welding gun posture is not matched with the turnover angle of the positioner, the robot may have the situation of interference or poor forming precision, so in one or more embodiments of the description, the position of the welding gun is taken as an example for illustration, and the positioner posture and the welding gun posture are always kept opposite.

For example, assume that the initial state of the torch is initially oriented in the positive y-axis direction. To print the intersecting region of the tube 2, the torch should be rotated along the y-z plane by a first spatial angle α, then rotated along the x-z direction by a second spatial angle β, and then rotated along the x-y plane by a third spatial angle θ such that the torch is oriented vertically toward the intersecting region. Therefore, the robot position and posture determining module 140 may obtain the corresponding robot posture transformation matrix based on the coordinate system shown in fig. 7, so as to obtain the robot posture. The mathematical formula can be calculated as follows:

wherein R is _x (α)、R _y (β)、R _z (theta) represents a rotation matrix corresponding to rotations alpha, beta, theta around X, Y, Z respectively,

is an overall transformation matrix. By passing

The robot position and pose determination module 140 may be based on primitiveAnd obtaining the welding gun position of the intersecting area.

Further, digital-analog slicing is performed based on the tangential direction of the central axis after the pose of the welding gun changes, and this method may refer to the corresponding description in step 250, which is not described herein again.

And 340, performing digital-to-analog slicing based on the tangential direction of the central axis of the pipeline when the change curve of the tangential slope is smaller than the first preset threshold.

When the change curve of the tangent slope is smaller than the first preset threshold, the method as in step 250 is adopted to perform slicing, which is not described herein again.

It should be understood that the above description of steps is exemplary only, and is not intended to limit the scope of the present disclosure. Many modifications and variations will be apparent to those skilled in the art in light of the description. However, such modifications and changes do not depart from the scope of the present specification.

Having thus described the basic concept, it will be apparent to those skilled in the art that the foregoing detailed disclosure is to be regarded as illustrative only and not as limiting the present specification. Various modifications, improvements and adaptations to the present description may occur to those skilled in the art, although not explicitly described herein. Such modifications, improvements and adaptations are proposed in the present specification and thus fall within the spirit and scope of the exemplary embodiments of the present specification.

Also, the description uses specific words to describe embodiments of the description. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the specification is included. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the specification may be combined as appropriate.

Moreover, those skilled in the art will appreciate that aspects of the present description may be illustrated and described in terms of several patentable species or situations, including any new and useful combination of processes, machines, manufacture, or materials, or any new and useful improvement thereof. Accordingly, aspects of this description may be performed entirely by hardware, entirely by software (including firmware, resident software, micro-code, etc.), or by a combination of hardware and software. The above hardware or software may be referred to as "data block," module, "" engine, "" unit, "" component, "or" system. Furthermore, aspects of the present description may be represented as a computer product, including computer readable program code, embodied in one or more computer readable media.

The computer storage medium may comprise a propagated data signal with the computer program code embodied therewith, for example, on baseband or as part of a carrier wave. The propagated signal may take any of a variety of forms, including electromagnetic, optical, etc., or any suitable combination. A computer storage medium may be any computer-readable medium that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code located on a computer storage medium may be propagated over any suitable medium, including radio, cable, fiber optic cable, RF, or the like, or any combination of the preceding.

Computer program code required for the operation of various portions of this specification may be written in any one or more programming languages, including an object oriented programming language such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C + +, C #, VB.NET, Python, and the like, a conventional programming language such as C, VisualBasic, Fortran2003, Perl, COBOL2002, PHP, ABAP, a dynamic programming language such as Python, Ruby, and Groovy, or other programming languages, and the like. The program code may run entirely on the device computer, as a stand-alone software package, partly on the device computer, partly on a remote computer or entirely on the remote computer or processing device. In the latter scenario, the remote computer may be connected to the device computer through any form of network, such as a Local Area Network (LAN) or a Wide Area Network (WAN), or the connection may be made to an external computer (for example, through the Internet), or in a cloud computing environment, or as a service, such as a software as a service (SaaS).

Additionally, the order in which the elements and sequences are processed, the use of alphanumeric characters, or the use of other designations in this specification is not intended to limit the order of the processes and methods in this specification, unless otherwise specified in the claims. While various presently contemplated embodiments of the invention have been discussed in the foregoing disclosure by way of example, it is to be understood that such detail is solely for that purpose and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements that are within the spirit and scope of the embodiments herein. For example, although the system components described above may be implemented by hardware devices, they may also be implemented by software-only solutions, such as installing the described system on an existing processing device or mobile device.

Similarly, it should be noted that in the preceding description of embodiments of the present specification, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure aiding in the understanding of one or more of the embodiments. This method of disclosure, however, is not intended to imply that more features than are expressly recited in a claim. Indeed, the embodiments may be characterized as having less than all of the features of a single embodiment disclosed above.

Numerals describing the number of components, attributes, etc. are used in some embodiments, it being understood that such numerals used in the description of the embodiments are modified in some instances by the use of the modifier "about", "approximately" or "substantially". Unless otherwise indicated, "about", "approximately" or "substantially" indicates that the number allows a variation of ± 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that may vary depending upon the desired properties of the individual embodiments. In some embodiments, the numerical parameter should take into account the specified significant digits and employ a general digit preserving approach. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the range are approximations, in the specific examples, such numerical values are set forth as precisely as possible within the scope of the application.

For each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., cited in this specification, the entire contents of each are hereby incorporated by reference into this specification. Except where the application history document is inconsistent or contrary to the present specification, and except where the application history document is inconsistent or contrary to the present specification, the application history document is not inconsistent or contrary to the present specification, but is to be read in the broadest scope of the present claims (either currently or hereafter added to the present specification). It is to be understood that the descriptions, definitions and/or use of terms in the accompanying materials of this specification shall control if they are inconsistent or contrary to the content of this specification.

Finally, it should be understood that the examples in this specification are only intended to illustrate the principles of the examples in this specification. Other variations are also possible within the scope of the present description. Thus, by way of example, and not limitation, alternative configurations of the embodiments of the present specification can be seen as consistent with the teachings of the present specification. Accordingly, the embodiments of the present description are not limited to only those embodiments explicitly described and depicted herein.

Claims

1. A manufacturing method of an arc-based additive multi-directional steel node elbow branch is characterized by comprising the following steps:

acquiring a digital model of the bent pipe part;

2. The method for manufacturing the elbow branch based on the arc additive multi-directional steel node according to claim 1, wherein the step of obtaining a central axis of a elbow part digifax comprises the steps of: and acquiring the central axis based on modeling information in the elbow part digital model.

3. The method for manufacturing the elbow branch based on the arc additive multi-directional steel node according to claim 1, wherein the step of obtaining the central axis of the elbow part digifax comprises the steps of: obtaining the central axis based on an image processing algorithm; the image processing algorithm comprises gray processing, binarization operation and a center line extraction algorithm, the gray processing and the binarization operation can obtain the minimum envelope surface of the bent pipe, the center line extraction algorithm can fit a circular profile surface based on the minimum envelope surface of the bent pipe, and the central axis is obtained based on the circular profile surface extraction.

4. The method of manufacturing an arc-based additive multi-directional steel node elbow branch of claim 1, wherein performing digital-to-analog slicing based on a tangent slope curve of a central axis of the pipeline to obtain a plurality of sliced layers further comprises: acquiring a tangent slope change curve corresponding to the tangent slope curve; determining a first preset threshold value of slope change; when the tangent slope change curve is larger than or equal to the first preset threshold, changing the pose of the robot/positioner of the current slicing layer, and performing digital-analog slicing based on the tangent direction of the central axis after the pose is changed; and when the change curve of the tangent slope is smaller than the first preset threshold value, performing digital-analog slicing based on the tangent direction of the central axis of the pipeline.

5. The method of manufacturing an arc-based additive multi-directional steel node elbow branch of claim 1, wherein performing digital-to-analog slicing based on a tangential direction of the central axis of the pipeline further comprises:

and when the thickness of the part of the digifax after slicing exceeds the upper limit value or the lower limit value of the melting height, correcting the slices of the plurality of adjacent layers of the slicing layer, and averaging the exceeding/missing parts of the part of the digifax into the plurality of adjacent layers so that the thickness of the slices of the whole digifax meets the requirement.

6. The manufacturing method of the arc-based additive multi-directional steel node elbow branch according to claim 1, wherein the arc process parameters comprise one or more of voltage, current, welding speed, pulse frequency, base current and peak current.

7. A system for manufacturing a multi-directional steel node elbow branch based on arc additive, the system comprising:

the tangent slope curve determining module is used for acquiring a central axis of the pipeline based on the elbow part digital model and determining a tangent slope curve of the central axis of the pipeline;

the system comprises a process parameter base acquisition module, a control module and a control module, wherein the process parameter base acquisition module is used for acquiring an electric arc additive manufacturing process parameter base, the process parameter base comprises the melting height of workpieces under different electric arc process parameters, and the upper limit value and the lower limit value of the melting height are determined in the process parameter base;

8. A system for manufacturing an arc-based additive multi-directional steel node elbow branch, the system comprising a processor for executing any one of the arc-based additive multi-directional steel node elbow branch manufacturing methods of claims 1-6.