Method, system and equipment for identifying cold extrusion area of fastener hole of structural part and medium

Abstract

The invention relates to the technical field of digital assembly design, in particular to a structural part fastener hole cold extrusion area identification method, system and equipment and a medium. The method comprises the following steps: firstly, searching and acquiring a cold extrusion area identifier, and judging whether a structural part has a cold extrusion area; secondly, according to fasteners assembled by structural parts, geometric information of assembly hole sites is obtained; basic information of the fastener is obtained, and a part fastener hole data model is constructed; and finally, identifying a cold extrusion hole site by analyzing and judging the spatial relationship between the fastener and the cold extrusion area identifier. According to the method, the three-dimensional fastener hole features are converted from recessive expression to dominant expression, then the fastener hole features and the spatial position of the closed surface patch in the cold extrusion area are analyzed, and the relation between the fastener hole and the closed surface patch is accurately recognized, so that the recognition accuracy and efficiency of the cold extrusion hole site are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of digital assembly process design, and specifically, to a method, system, device, and medium for identifying cold extrusion areas of fastener holes in structural parts. Background Art

[0002] A process specification is a productive process document compiled by the process department according to design requirements, process technical requirements, and quality requirements. The process specification not only includes process information but also production information and quality information, and is a specific work instruction guiding workers to actually operate the specified assembly process flow, including operation instructions, processes, assembly time sequences, change records, and other information.

[0003] Currently, process specifications are still mainly compiled manually, with a long cycle for the process specification compilation work, poor standardization of the process specification compilation results, and even some quality errors. Therefore, realizing the automatic compilation of process specifications has become an urgent problem to be solved in aircraft development and production, and the automatic identification of aircraft parts and features is an important factor restricting the automatic compilation and planning of process specifications.

[0004] To improve the fatigue resistance of the airframe structure, implementing a cold extrusion process on structural fastener holes is one of the main measures for aircraft structure life extension. By using a powerful pressure to cause plastic deformation of the metal material, the mechanical properties and surface quality of structural parts are improved.

[0005] In the process preparation stage, when process personnel identify the cold extrusion area, they need to compare the cold extrusion area markings of the part digital model with the part digital model, and then compile the cold extrusion process requirements in the process instructions. The cold extrusion area markings are usually in the form of irregular closed patches, wrapping as many fastener holes to be cold extruded as possible within the closed patches, and the closed patches are saved in the three-dimensional digital model of the part. Due to the large number of fastener hole positions and the scattered distribution of cold extrusion hole positions in aviation parts, the closed patches do not tightly wrap a single fastener hole, and the wrapped area is large. In addition, in the three-dimensional digital model of structural parts, the spatial position relationship between fasteners and parts is often used to implicitly represent the fastener holes on the structural parts, lacking the actual existing three-dimensional fastener hole features.

[0006] Currently, visual identification is still one of the main methods for identifying cold extrusion structural fastener holes. In a complex space, it is very difficult to visually identify whether a fastener has an assembly relationship with the part and whether it is inside the closed patch. Problems such as missed identification and misidentification may occur, resulting in a situation where the actual state is inconsistent with the design state, and the visual identification method cannot meet the requirements of automatic compilation and planning of process specifications. Summary of the Invention

[0007] In view of the problem of low efficiency in the cold extrusion requirements for visually identifying the holes of structural fasteners, the present invention proposes a method, system, device and medium for identifying the cold extrusion area of the holes of structural parts fasteners; the method first searches for and obtains the cold extrusion area identifier, and judges whether the structural part has a cold extrusion area; secondly, according to the fasteners assembled on the structural part, the geometric information of the assembled hole positions is obtained; then the basic information of the fasteners is obtained, and a data model of the fasteners holes of the part is constructed; finally, according to the analysis and judgment of the spatial relationship between the fasteners and the cold extrusion area identifier, the cold extrusion hole positions are identified; by converting the three-dimensional fasteners hole features from implicit expression to explicit expression, and then analyzing the spatial positions of the fasteners hole features and the closed patches of the cold extrusion area, the accuracy and efficiency are improved.

[0008] The specific implementation content of the present invention is as follows: A method for identifying the cold extrusion area of the holes of structural parts fasteners, first judges whether the structural part has a cold extrusion area according to the cold extrusion area identifier searched for and obtained; secondly, according to the fasteners assembled on the structural part, the geometric information of the assembled hole positions is obtained; then according to the obtained geometric information of the assembled hole positions, the basic information of the fasteners is obtained, and a data model of the fasteners holes of the part is constructed; finally, according to the cold extrusion area identifier and the data model of the fasteners holes of the part, the spatial relationship between the fasteners and the cold extrusion area identifier is analyzed and judged, and the cold extrusion hole positions are identified.

[0009] In order to better implement the present invention, further, the method for identifying the cold extrusion area of the holes of structural parts fasteners specifically includes the following steps: Step S1: Obtain the cold extrusion area identifier according to the obtained STG model, and judge whether the structural part has a cold extrusion area, where the STG model is a model established with the local features of the three-dimensional model as vertices and the adjacency relationship between local features as edges; Step S2: According to the fasteners assembled on the structural part, obtain the geometric information of the assembled hole positions, and establish a mapping relationship between the fasteners holes of the part and the fasteners; Step S3: Obtain the basic information of the fasteners according to the obtained mapping relationship between the fasteners holes of the part and the fasteners, and construct a data model of the fasteners holes of the part; Step S4: Summarize the geometric data according to the cold extrusion area identifier and the data model of the fasteners holes of the part, and call geometric calculation to analyze and judge the spatial relationship between the fasteners and the cold extrusion area identifier, and identify the cold extrusion hole positions.

[0010] In order to better implement the present invention, further, the step S1 specifically includes the following steps: Step S11: Obtain the structural part pp from the obtained STG model; Step S12: Search for and obtain the cold extrusion area identifier according to the geometric graphic set nodes; Step S13: Determine whether the structural part pp has a cold extrusion area according to the cold extrusion area identifier.

[0011] To better implement the present invention, further, the step S2 specifically includes the following steps: Step S21: Extract the assembly relationship between structural parts according to the STG model; Step S22: Obtain the fastener information having an assembly relationship with the structural part pp according to the assembly relationship; Step S23: Obtain the geometric information of the assembly hole positions according to the fastener information, and establish the mapping relationship between the part fastener hole positions and the fasteners.

[0012] To better implement the present invention, further, the step S21 specifically includes the following steps: Step S211A: Describe the name and shape information of the obtained structural parts; Step S212A: Use the double interference test method to obtain the connection relationship between structural parts and establish an adjacency model; Step S213A: Calculate the set of connection relationship features matching the structural part classification rule library according to the name and shape information of the structural parts; Step S214A: Use the matching relationship as the search space to obtain the assembly relationship between structural parts.

[0013] To better implement the present invention, further, the step S211A specifically includes the following steps: Step S2111A: Initialize the structural part category set C; Step S2112A: Obtain the name id of the model file corresponding to the structural part pp pp ; Step S2113A: Determine whether the part category c of the structural part pp pp belongs to the category set C. If not, call the shape distribution algorithm to describe the shape information of the structural part pp as a k-dimensional shape vector s pp , and establish a part descriptor <id pp , s pp >, and add the structural part pp as a new part category c pp to the category set; Step S2114A: If the name id of the structural part model file pp =id qq , id qq ∈c qq , then establish a part descriptor <id qq , s qq >, id qqis the name of the model file corresponding to part qq, c qq is the part category of part qq; Step S2115A: Repeat steps S2112A - S2114A until all parts are traversed.

[0014] To better implement the present invention, further, the step S212A specifically includes the following steps: Step S2121A: Obtain assembly I from the structural part classification rule library, initialize the m×m dimensional adjacency matrix G, and calculate the AABB bounding box R of the structural part; where m is the number of parts in the to-be-recognized structural part model A; Step S2122A: Select the structural part pp’ from assembly I and initialize the set S; Step S2123A: Randomly obtain part qq from assembly I. If the bounding box R pp’ ∩R qq ≠ , then add part qq to set S. R pp’ is the AABB bounding box of part pp’, and R qq is the AABB bounding box of part qq; Step S2124A: According to part qq in set S, call the octree interference checking algorithm to perform spatial interference checking on structural part pp’ and part qq. If the checking result is contact or interference, then the adjacency matrix G pp’qq = 1; Step S2125A: Repeat steps S2122A - S2124A until all parts of assembly I are traversed.

[0015] To better implement the present invention, further, the step S213A specifically includes the following steps: Step S2131A: Initialize the matching part set Com pp ; Step S2132A: Add the structural part with the name id pp in the to-be-recognized finished product model A to the matching part set Com pp ; Step S2133A: Calculate the shape vector s pp of structural part pp and the similarity with the shape vector s i of the parts in the i-th category of the part category set C; Step S2134A: According to the set shape similarity threshold, determine whether the similarity is greater than or equal to the shape similarity threshold. If so, add all parts in the i-th category to the matching part set Com pp .

[0016] In order to better implement the present invention, further, the shape vector s of the structural part pp is calculated in step S2133A pp The shape vector s of the part in the i-th category in the part category set C i The formula for the similarity is: ; Among them, s pp represents the shape vector of the structural part pp, k represents the dimension of the k-dimensional shape vector of the part, l j pp represents the j-th shape vector of the structural part pp, l j qq Represents the j-th shape vector of part qq in the i-th category.

[0017] In order to better implement the present invention, further, the specific operation of step S2134A is: according to the set shape similarity threshold ε, if the similarity sim(s pp ,s i )≥ε, then add all parts in the i-th category to the matching parts set Com pp ,s i is the shape vector of the parts in the i-th category.

[0018] In order to better implement the present invention, further, the specific operation of step S414A is: using the part matching relationship as the search space, calling the Ullmann subgraph matching algorithm in the adjacency matrix G of the finished product model A to be identified A Search the adjacency matrix G with assembly I I The subgraphs with the same structure are matched to identify the assembly relationship between the structural parts.

[0019] In order to better implement the present invention, further, the step S21 specifically includes the following steps: Step S211B: constructing a structural parts assembly relationship instance library according to the acquired STG model; Step S212B: converting the acquired structural part shape information into a k-dimensional vector according to the constructed structural part assembly relationship instance library, and calculating a neighbor vector set according to the acquired spatial neighbor characteristics between the structural parts; Step S213B: searching for a matching candidate set of the three-dimensional model of the structural part according to the k-dimensional vector and the nearest neighbor vector set; Step S214B: According to the matching candidate set, the spatial distribution aggregation of the matching structural parts is obtained, and the assembly relationship between the structural parts is identified.

[0020] In order to better implement the present invention, further, step S212B specifically includes the following steps: Step S2121B: Obtain structure part instances according to the constructed instance library of the assembly relationship of structure parts, and construct an OBB bounding box for the structure parts; the structure part instances include the maximum length, maximum width, and maximum height of the structure parts. Step S2122B: Judge the spatial distribution relationship between parts according to the interference situation of the bounding boxes, and obtain a set of neighbor vectors. Step S2123B: Repeat Step S2121B - Step S2122B until each part in the structure part model and the instance library of the assembly relationship of structure parts is traversed.

[0021] To better implement the present invention, further, the specific steps of Step S213B include the following steps: Step S2131B: Coarsely filter part pp according to the set shape similarity threshold and the similarity between structure part pp and part qq to obtain an initial set. Step S2132B: Calculate the similarity between the parts in the initial set and the neighbor set of structure part pp according to the initial set. Step S2133B: Match the initial set according to the set neighbor similarity threshold and neighbor similarity to obtain a matching candidate set.

[0022] To better implement the present invention, further, the specific steps of Step S214B include the following steps: Step S2141B: Construct an ordered set according to the size of the neighbor set of parts in the structure part instance. Step S2142B: Initialize set list, set Ca, set Flag, and set Tar. Step S2143B: Assign the ordered set to set list. If structure part pp is the first element of set list, assign the matching candidate set to set Ca. Step S2144B: Randomly select part qq1 from set Ca and judge whether it meets the set criterion conditions. Step S2145B: If not, assign Ca - {qq1} to set Ca, and assign Ca pp - {qq1} to the matching candidate set Ca of part pp pp ; if the set , then select the next part qq2 in set Ca and return to Step S2144B; if the set , then end the search; Ca - {qq1}, Ca pp - {qq1} are respectively the sets after removing element {qq1} from Ca and Ca pp ; Step S2146B: If the set criterion holds, add the structural part pp to the set Flag, and simultaneously establish an ordered set list of the neighbor vector set Nei of part pp pp of the ordered set list pp ; Step S2147B: If , then use the part set corresponding to the output set Tar as the assembly relationship, assign to the set list, assign Ca pp -{qq1} to the set Ca, and return to Step S2144B; Step S2148B: If , then assign to the set Tar, assign to the set Ca, assign list pp to the set list, and return to Step S2144B, is the neighbor vector set of part qq1; Step S2149B: The output set Tar is the assembly relationship of the matching structural parts.

[0023] To better implement the present invention, further, the Step S3 specifically includes the following steps: Step S31: Obtain the basic fastener information according to the mapping relationship between the fastener hole positions and the fasteners; the basic fastener information includes the fastener drawing number, fastener instance number, fastener name, fastener structure tree path, and fastener axis endpoint coordinates; Step S32: Combine the obtained basic fastener information with the mapping relationship between the fastener hole positions and the fasteners to construct a part fastener hole data model.

[0024] To better implement the present invention, further, the Step S4 specifically includes the following steps: Step S41: Obtain the coordinate sp of the starting point of the fastener axis relative to the part coordinate system and the coordinate ep of the ending point of the fastener axis relative to the part coordinate system according to the basic fastener information; Step S42: According to the starting point coordinate sp, ending point coordinate ep of the fastener axis, and transformation matrix rm, perform matrix operations to obtain the starting point sppp in the part coordinate system and the ending point eppp in the part coordinate system; Step S43: In the part coordinate system, establish a geometric ray that extends infinitely in the starting point direction, and call the SetLineType function in the CAD secondary development interface to set the line to the StartInf mode; Step S44: Call the CAD secondary development interface GetIntersect method to perform an intersection operation between the geometric ray and the cold extrusion area identifier. If there are no intersecting elements, it is determined that there is no cold extrusion area in the current fastener hole; if there are intersecting elements, obtain all the point elements and store them in the point set List. The number of elements in the point set is num, and the index starts from 1. Step S45: Use the singularity theorem to determine the relationship between the identifier and the fastener axis; if the number of elements in the point set List is odd, the fastener hole is a cold extrusion area; otherwise, further judgment is made. Add the starting point sppp and the ending point eppp of the fastener axis to the point set List, establish a normalized vector vec pointing from the ending point eppp to the starting point sppp, and sort the point set List along the direction from the ending point to the starting point using the projection value of the coordinates in the direction of the vector vec. Step S46: Retrieve the index k of the starting point sppp in the point set List. If the number of elements pnum = num - k from the starting point sppp to the last intersection point is even, it is determined that the fastener hole is a cold extrusion area; otherwise, the fastener hole is a non-cold extrusion area.

[0025] To better implement the present invention, further, the cold extrusion area identification method for the fastener holes of the structural parts further includes step S5: In the constructed data model of the part fastener holes, traverse the basic information of each fastener, and execute steps S41 - S46 until all the cold extrusion areas of the part are obtained.

[0026] To better implement the present invention, further, the establishment process of the STG model in step S1 is as follows: First, establish a vertex adjacency graph according to the topological relationship between the geometric elements of the obtained B-rep data; secondly, search for the maximum cliques in the adjacency graph and use the geometric regions corresponding to the maximum cliques as local features of the solid model; then call a statistical method to transform the shape information of the local features into feature vectors, form a feature space, and use an unsupervised learning algorithm to suppress the local features; finally, establish an STG model with the local features as vertices and the adjacency relationship between the local features as edges.

[0027] Based on the above-mentioned cold extrusion area identification method for the fastener holes of the structural parts, to better implement the present invention, further, a cold extrusion area identification system for the fastener holes of the structural parts is proposed, which is used to execute the above-mentioned cold extrusion area identification method for the fastener holes of the structural parts; it includes a search unit, an acquisition unit, a construction unit, and an identification unit. The search unit is used to determine whether the structural part has a cold extrusion area according to the searched and obtained cold extrusion area identifier. The acquisition unit is used to obtain the geometric information of the assembly hole positions according to the fasteners assembled on the structural part. The building unit is used to obtain the basic information of fasteners according to the acquired geometric information of assembly hole positions and construct a part fastener hole data model. The recognition unit is used to analyze and judge the spatial relationship between the fastener and the cold extrusion area identifier according to the cold extrusion area identifier and the part fastener hole data model, and recognize the cold extrusion hole positions.

[0028] Based on the above-mentioned method for identifying the cold extrusion area of fastener holes in structural parts, in order to better implement the present invention, further, an electronic device is proposed, which includes a memory and a processor; a computer program is stored on the memory; when the computer program is executed on the processor, the above-mentioned method for identifying the cold extrusion area of fastener holes in structural parts is realized.

[0029] Based on the above-mentioned method for identifying the cold extrusion area of fastener holes in structural parts, in order to better implement the present invention, further, a computer-readable storage medium is proposed, and a computer instruction is stored on the computer-readable storage medium; when the computer instruction is executed on the above-mentioned electronic device, the above-mentioned method for identifying the cold extrusion area of fastener holes in structural parts is realized.

[0030] The present invention has the following beneficial effects: (1) By accurately identifying the relationship between the fastener holes and the closed surface patches, the present invention improves the recognition accuracy and efficiency of cold extrusion hole positions.

[0031] (2) The present invention converts the three-dimensional fastener hole features from implicit expression to explicit expression, and then analyzes the spatial positions of the fastener hole features and the closed surface patches of the cold extrusion area. Compared with the traditional visual recognition, it has higher accuracy and efficiency. Description of the Drawings

[0032] Figure 1 It is a schematic diagram of the fast recognition process of the cold extrusion area of structural parts provided by the present invention.

[0033] Figure 2 It is an example diagram of structural parts and the cold extrusion area provided by the present invention. Detailed Embodiments

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments, and therefore should not be regarded as limiting the protection scope. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technical staff in the art without creative work fall within the protection scope of the present invention.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "set", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can also be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] Embodiment 1: This embodiment proposes a method for identifying the cold extrusion area of the fastener holes of structural parts. First, according to the obtained cold extrusion area identifier, it is judged whether the structural part has a cold extrusion area; secondly, according to the fasteners assembled on the structural part, the geometric information of the assembled hole positions is obtained; then, according to the obtained geometric information of the assembled hole positions, the basic information of the fasteners is obtained, and a data model of the part fastener holes is constructed; finally, according to the cold extrusion area identifier and the data model of the part fastener holes, the spatial relationship between the fasteners and the cold extrusion area identifier is analyzed and judged to identify the cold extrusion hole positions.

[0037] Working principle: In this embodiment, the three-dimensional fastener hole features are converted from implicit expression to explicit expression, and then the spatial positions of the fastener hole features and the closed patches of the cold extrusion area are analyzed. Compared with the traditional visual identification, it has higher accuracy and efficiency.

[0038] Embodiment 2: This embodiment is described in the form of steps on the basis of the above Embodiment 1.

[0039] The method for identifying the cold extrusion area of the fastener holes of the structural parts specifically includes the following steps: Step S1: Obtain the cold extrusion area identifier according to the obtained STG model, and judge whether the structural part has a cold extrusion area.

[0040] Further, the step S1 specifically includes the following steps: Step S11: Obtain the structural part pp from the obtained STG model; Step S12: Search and obtain the cold extrusion area identifier according to the geometric graphic set nodes; Step S13: Judge whether the structural part pp has a cold extrusion area according to the cold extrusion area identifier.

[0041] Among them, the STG model obtained in step S1 of this embodiment is to first establish a vertex adjacency graph according to the topological relationship between geometric elements such as vertices and faces in the B-rep data; search for the maximum cliques in the graph and use the corresponding geometric regions as the local features of the model; based on statistical methods, convert the shape information of the local features into feature vectors to form a feature space, and use an unsupervised learning algorithm to suppress the differences of the local features so that the locally similar features have the same encoding; finally, establish an STG model with local features as vertices and adjacency relationships as edges.

[0042] Step S2: Obtain the geometric information of the assembly hole positions according to the fasteners for assembling the structural parts, and establish the mapping relationship between the part fastener holes and the fasteners. The said step S2 specifically includes the following steps: Step S21: Extract the assembly relationship between the structural parts according to the STG model. Step S22: Obtain the fastener information having an assembly relationship with the structural part pp according to the said assembly relationship. Step S23: Obtain the geometric information of the assembly hole positions according to the said fastener information, and establish the mapping relationship between the part fastener holes and the fasteners.

[0043] Step S3: Obtain the basic information of the fasteners according to the mapping relationship between the part fastener holes and the fasteners, and construct a part fastener hole data model.

[0044] The said step S3 specifically includes the following steps: Step S31: Obtain the basic information of the fasteners according to the mapping relationship between the firmware hole positions and the fasteners; the said basic information of the fasteners includes fastener drawing number, fastener instance number, fastener name, fastener structure tree path, fastener axis endpoint coordinates. Step S32: Combine the obtained basic information of the fasteners with the mapping relationship between the fastener holes and the fasteners to construct a part fastener hole data model.

[0045] Step S4: Summarize the geometric data according to the cold extrusion area identifier and the part fastener hole data model, call geometric calculation to analyze and judge the spatial relationship between the fasteners and the cold extrusion area identifier, and identify the cold extrusion hole positions.

[0046] The said step S4 specifically includes the following steps: Step S41: Obtain the coordinate sp of the starting point of the fastener axis relative to the part coordinate system and the coordinate ep of the ending point of the fastener axis relative to the part coordinate system according to the basic information of the fasteners. Step S42: According to the starting point coordinate sp, ending point coordinate ep of the fastener axis and the transformation matrix rm, perform matrix operations to obtain the starting point sppp in the part coordinate system and the ending point eppp in the part coordinate system. Step S43: In the part coordinate system, establish a geometric ray that extends infinitely in the starting direction, and call the SetLineType function in the CAD secondary development interface to set the line to the StartInf mode; Step S44: Call the GetIntersect method of the CAD secondary development interface to perform an intersection operation between the geometric ray and the cold extrusion area identifier. If there are no intersecting elements, it is determined that there is no cold extrusion area in the current fastener hole; if there are intersecting elements, obtain all the point elements and store them in the point set List. The number of elements in the point set is num, and the index starts from 1; Step S45: Use the singularity theorem to judge the relationship between the identifier and the axis of the fastener; if the number of elements in the point set List is odd, the fastener hole is a cold extrusion area; otherwise, further judgment is made. Add the starting point sppp and the ending point eppp of the fastener axis to the point set List, establish a normalized vector vec pointing from the ending point eppp to the starting point sppp, and sort the point set List in the direction from the ending point to the starting point using the projection value of the coordinates in the direction of the vector vec; Step S46: Retrieve the index k of the starting point sppp in the point set List. If the number of elements pnum = num - k from the starting point sppp to the last intersection point is even, it is determined that the fastener hole is a cold extrusion area; otherwise, the fastener hole is a non-cold extrusion area.

[0047] Step S5: In the constructed part fastener hole data model, traverse each fastener basic information and execute Step S41 - Step S46 until all the cold extrusion areas of the part are obtained.

[0048] Working principle: In this embodiment, first, search and obtain the cold extrusion area identifier according to the part three-dimensional digital model, and judge whether the structural part has a cold extrusion area by identifying the cold extrusion area identifier; secondly, use the fasteners assembled on the part to obtain the geometric information of the assembly hole positions. Extract the assembly relationship between the parts according to the assembly digital model, identify the fastener information having an assembly relationship with the part described in the first step, and establish a mapping relationship between the part fastener hole positions and the fasteners; then obtain the fastener basic information according to the obtained mapping relationship between the part fastener hole positions and the fasteners, obtain the drawing number, name, structure tree path, and axis endpoint coordinates of the fasteners, and construct a part fastener hole data model; finally, summarize the geometric data according to the obtained cold extrusion area identifier and the obtained part fastener hole position model, analyze and judge the spatial relationship between the fasteners and the cold extrusion area identifier through geometric calculations, and summarize the basic information of the fastener hole positions included in the cold extrusion area to meet the rapid identification of the cold extrusion area of the part.

[0049] Other parts of this embodiment are the same as those of the above Embodiment 1, so they will not be described in detail.

[0050] Example 3: This example is based on any one of the above Examples 1 - 2. As Figure 1 , Figure 2 shown, a specific example will be described in detail.

[0051] Step S1: Search for and obtain the cold extrusion area identifier of the structural part.

[0052] For the structural part pp, search for the geometric graphic set node with "cold extrusion area" in the structure tree in the 3D CAD software, and filter the closed patch geometric elements under this node; store the geometric element node in the Object container of the secondary development interface of the 3D CAD software; provide the cold extrusion area recognition method only for the parts with closed patch geometric elements. The selected structural part and the cold extrusion area identifier in this case are as Figure 2 shown. The yellow area in the figure is the cold extrusion area identifier to be searched. After positioning the area, the cold extrusion hole positions are identified in combination with the assembly relationship.

[0053] Step S2: Extract the assembly relationship between the zero parts according to the assembly digital model.

[0054] Extract each assembly relationship information in the assembly model, summarize the assembly relationship information related to the structural part pp, identify the corresponding fastener nodes according to the drawing number, and establish the mapping relationship KP = {kp1, kp2,..., kpi,..., kpn} between the part fastener holes and the fasteners, where kpi represents the standard part node corresponding to the i-th fastener hole of the structural part pp, and there are n assembly holes in total. Store the n assembly hole nodes in the Vector of the secondary development interface of the 3D CAD software <object>In the container set.

[0055] Step S3: Build the data model of the part fastener holes.

[0056] According to the mapping relationship KP of the structural part pp, obtain n basic fastener information ST = {pn, in, name, rm, sp, ep}, where pn is the drawing number, in is the instance number, name is the name, rm is the transformation matrix, sp is the starting coordinate of the fastener axis, and ep is the ending coordinate of the fastener axis. Combine the above information with the mapping relationship KP of the structural part pp to build the data model of the part fastener holes MST = {ST1, ST2, ST3, …, STi, …, STn}, which expresses the attributes and geometric information of n fastener holes in the structural part pp.

[0057] Step S4: Judge the spatial relationship between the fastener and the mark, and identify the cold extrusion area of the part.

[0058] For the basic fastener information ST, obtain the coordinates of the starting point and the ending point of the fastener axis relative to the part coordinate system. According to the starting point sp and the ending point coordinate ep of the fastener axis obtained in step S3 and the transformation matrix rm, perform matrix operations to obtain the starting point sppp = rm * sp and the ending point eppp = rm * ep in the part coordinate system.

[0059] In the part coordinate system, establish a geometric ray with an infinitely extending starting direction, and use the SetLineType function in the secondary development interface of the 3D CAD software to set the line to the StartInf mode.

[0060] Use the GetIntersect method in the secondary development interface of the 3D CAD software to perform an intersection operation between the geometric ray and the mark. If there is no intersecting element, it is determined that there is no cold extrusion area for this fastener hole. If there are intersecting elements, obtain all the point elements among them and store them in the point set List. The number of elements in the point set is num, and the index starts from 1.

[0061] Use the singularity theorem to judge the relationship between the mark and the fastener axis. If the number of elements in the point set List is odd, then this fastener hole is a cold extrusion area. Otherwise, further judgment is required. Add the starting point sppp and the ending point eppp of the fastener axis to the point set List. Establish a normalized vector vec pointing from the ending point eppp to the starting point sppp. Sort the point set List in the direction from the ending point to the starting point using the projection value of the coordinates in the direction of the vector vec.

[0062] Retrieve the index k of the starting point sppp in the point set List. If the number of elements pnum = num - k from the starting point to the last intersection point is even, then it is determined that this fastener hole is a cold extrusion area. Otherwise, this fastener hole is a non-cold extrusion area.

[0063] In the part fastener hole data model MST constructed in step S3, traverse the n basic fastener information ST, execute the above judgment, and obtain all the cold extrusion areas of the part.

[0064] Other parts of this embodiment are the same as any one of the above embodiments 1-2, so they will not be described in detail.

[0065] Embodiment 4: Based on any one of the above embodiments 1-3, this embodiment illustrates step S21 with a specific example.

[0066] The step S21 specifically includes the following steps: Step S21A: Extract the assembly relationship between structural parts according to the STG model.

[0067] The step S21A specifically includes the following steps: Step S211A: Describe the name and shape information of the obtained parts. The step S211A specifically includes the following steps: Step S2111A: Initialize the set C of structural part categories. Step S2112A: Obtain the name id of the model file corresponding to the structural part pp pp ; Step S2113A: Judge whether the part category c of the structural part pp pp belongs to the category set C. If not, call the shape distribution algorithm to describe the shape information of the structural part pp as a k-dimensional shape vector s pp , and establish a part descriptor <id pp , s pp >, and add the structural part pp as a new part category c pp to the category set; Step S2114A: If the name id of the structural part model file pp =id qq , id qq ∈c qq , then establish a part descriptor <id qq , s qq >, id qq is the name of the model file corresponding to the part qq, and c qq is the part category of the part qq; Step S2115A: Repeat steps S2112A - S2114A until all parts are traversed.

[0068] Step S212A: Obtain the connection relationship between parts using a double interference testing method and establish an adjacency model.

[0069] The step S212A specifically includes the following steps: Step S2121A: Obtain the assembly I from the structural part classification rule library, initialize the m×m dimensional adjacency matrix G, and calculate the AABB bounding box R of the structural parts; where m is the number of parts in the to-be-identified structural part model A. Step S2122A: Select the structural part pp’ from the assembly I and initialize the set S. Step S2123A: Randomly obtain the part qq from the assembly I. If the bounding box R pp’ ∩Rq q ≠ , then add the part qq to the set S. R pp’ is the AABB bounding box of the part pp’, and R qq is the AABB bounding box of the part qq. Step S2124A: According to the part qq in the set S, call the octree interference testing algorithm to perform spatial interference testing on the structural part pp’ and the part qq. If the test result is contact or interference, then the adjacency matrix G pp’qq = 1; Step S2125A: Repeat steps S2122A - S2124A until all parts of the assembly I are traversed.

[0070] Step S213A: Calculate the connection relationship feature set that matches the finished product installation classification rule library according to the name and shape information of the finished product. The step S213A specifically includes the following steps: Step S2131A: Initialize the matching part set Com pp ; Step S2132A: Add the structural part with the name id pp in the to-be-identified finished product model A to the matching part set Com pp ; Step S2133A: Calculate the similarity between the shape vector s pp of the structural part pp and the shape vector s i of the parts in the i-th category of the part category set C. The specific operation of the step S2133A is: ; where s pp represents the shape vector of the structural part pp, k represents the dimension of the k-dimensional shape vector of the part, and l j pp Represents the j - dimensional shape vector of the structural part pp, l j qq Represents the j - dimensional shape vector of the part qq in the i - th category.

[0071] Step S2134A: According to the set shape similarity threshold, determine whether the similarity is greater than or equal to the shape similarity threshold. If so, add all parts in the i - th category to the matching part set Com pp .

[0072] The specific operation of the said step S2134A is: According to the set shape similarity threshold ε, determine whether the similarity sim(s pp , s i ) is greater than or equal to the shape similarity threshold. If the similarity sim(s pp , s i ) ≥ ε, then add all parts in the i - th category to the matching part set Com pp , that is, Com pp = Com pp ∪ {c i |sim(s pp , s i ) ≥ ε}, where 1 ≤ i ≤ n and qq ≠ pp, s i is the shape vector of the part in the i - th category, and c i is the set of parts in the i - th category of the part category set C.

[0073] Step S214A: Using the matching relationship as the search space, obtain the assembly relationship.

[0074] The specific operation of the said step S214A is: Taking the part matching relationship as the search space, call the Ullmann sub - graph matching algorithm to search for the sub - graph matching result with the same structure as the adjacency matrix G A in the structural part model A and the adjacency matrix G I of the assembly body I, and identify the assembly relationship between the structural parts.

[0075] Other parts of this embodiment are the same as any one of the above - mentioned Embodiment 1 - Embodiment 3, so they will not be elaborated here.

[0076] Embodiment 5: Based on any one of the above - mentioned Embodiment 1 - Embodiment 4, this embodiment illustrates step S21 in another implementation manner. The said step S21 specifically includes the following steps: Step S211B: According to the obtained STG model, construct an instance library of structural part assembly relationships.

[0077] Step S212B: According to the established instance library of the assembly relationship of structural parts, convert the obtained shape information of the structural parts into a k-dimensional vector, and calculate the set of neighbor vectors according to the obtained spatial neighbor characteristics between the structural parts.

[0078] Furthermore, the step S212B specifically includes the following steps: Step S2121B: According to the established instance library of the assembly relationship of structural parts, obtain the structural part instance and construct the OBB bounding box of the structural part; the structural part instance includes the maximum length, maximum width, and maximum height of the structural part pp. Step S2122B: Judge the spatial distribution relationship between parts according to the bounding box interference situation, and obtain the set of neighbor vectors. Step S2123B: Repeat Step S2121B - Step S2122B until each part in the structural part model and the instance library of the assembly relationship of structural parts is traversed.

[0079] Step S213B: Search for the matching candidate set of the 3D model of the structural part according to the k-dimensional vector and the set of neighbor vectors. The step S213B specifically includes the following steps: Step S2131B: Coarsely filter the part pp according to the set shape similarity threshold and the similarity between the structural part pp and the part qq to obtain the initial set. Step S2132B: Calculate the similarity between the parts in the initial set and the neighbor set of the structural part pp according to the initial set. Step S2133B: Match the initial set according to the set neighbor similarity threshold and the neighbor similarity to obtain the matching candidate set.

[0080] Step S214B: Obtain the spatial distribution aggregation of the matching structural parts according to the matching candidate set, and identify the assembly relationship between the structural parts.

[0081] The step S214B specifically includes the following steps: Step S2141B: Construct an ordered set according to the size of the part neighbor set in the structural part instance. Step S2142B: Initialize the set list, set Ca, set Flag, and set Tar. Step S2143B: Assign the ordered set to the set list. If the structural part pp is the first element of the set list, assign the matching candidate set to the set Ca. Step S2144B: Randomly select a part qq1 from the set Ca and judge whether it meets the set criterion conditions. Step S2145B: If not satisfied, assign Ca - {qq1} to set Ca, and assign Ca pp - {qq1} to the matching candidate set Ca of part pp pp ; If the set , then select the next part qq2 in set Ca and return to step S2144B; If the set , then end the search; Ca - {qq1}, Ca pp - {qq1} are the sets obtained by removing element {qq1} from Ca and Ca pp respectively; Step S2146B: If the set criterion is satisfied, add the structural part pp to set Flag, and at the same time establish an ordered set list pp of the neighbor vector set Nei pp of part pp; Step S2147B: If , then take the part set corresponding to the output set Tar as the assembly relationship, assign to set list, assign Ca pp - {qq1} to set Ca, and return to step S2144B; Step S2148B: If , then assign to set Tar, assign to set Ca, assign list pp to set list, and return to step S2144B, is the neighbor vector set of part qq1; Step S2149B: Take the output set Tar as the assembly relationship of the matching structural parts.

[0082] Other parts of this embodiment are the same as any one of the above Embodiment 1 - Embodiment 4, so they will not be elaborated here.

[0083] Embodiment 6: Based on any one of the above Embodiment 1 - Embodiment 5, this embodiment proposes a cold extrusion area recognition system for structural part fastener holes, which is used to execute the above-mentioned cold extrusion area recognition method for structural part fastener holes; it includes a search unit, an acquisition unit, a construction unit, and an identification unit; The search unit is used to judge whether the structural part has a cold extrusion area according to the searched and acquired cold extrusion area identifier; The acquisition unit is used to acquire the geometric information of the assembly hole position according to the fastener assembled on the structural part; The construction unit is used to acquire the basic information of the fastener according to the acquired geometric information of the assembly hole position and construct a part fastener hole data model; The recognition unit is configured to analyze and judge the spatial relationship between the fastener and the cold extrusion area identifier according to the cold extrusion area identifier and the part fastener hole data model, and recognize the cold extrusion hole position.

[0084] This embodiment also provides an electronic device, including a memory and a processor; a computer program is stored on the memory; when the computer program is executed on the processor, the above-mentioned method for identifying the cold extrusion area of the fastener hole of the structural part is implemented.

[0085] This embodiment also provides a computer-readable storage medium, on which a computer instruction is stored; when the computer instruction is executed on the above-mentioned electronic device, the above-mentioned method for identifying the cold extrusion area of the fastener hole of the structural part is implemented.

[0086] Other parts of this embodiment are the same as any one of the above Embodiment 1 - Embodiment 5, and thus will not be described in detail.

[0087] The processor involved in the embodiment of this application may be a chip. For example, it may be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processing circuit (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0088] The memory involved in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM). It should be noted that the memory of the systems and methods described herein is intended to include but not be limited to these and any other suitable types of memory.

[0089] It should be understood that in various embodiments of the present application, the magnitudes of the serial numbers of the above processes do not mean the order of execution is prior or subsequent. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0090] Those of ordinary skill in the art can realize that the modules and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0091] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and modules described above can refer to the corresponding processes in the foregoing method embodiments, and will not be described herein again.

[0092] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections between each other can be through some interfaces. The indirect couplings or communication connections of devices or modules can be in electrical, mechanical, or other forms.

[0093] The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical modules, that is, they can be located in one device or distributed to multiple devices. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0094] In addition, in each embodiment of the present application, the functional modules can be integrated in one device, or each module can exist physically alone, or two or more modules can be integrated in one device.

[0095] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using a software program, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from a website, a computer, a server, or a data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, Digital Subscriber Line (DSL)) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that the computer can access or a data storage device such as a server or a data center that contains one or more integrated media. The available medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a DVD), or a semiconductor medium (such as a Solid State Disk (SSD)), etc.

[0096] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claimed rights.< / object>

Claims

1. A method for identifying the cold extrusion area of the hole of a structural part fastener, characterized in that It includes the following steps: Step S1: Obtain the cold extrusion area identifier according to the acquired STG model, and determine whether the structural part has a cold extrusion area. The STG model is a model established with the local features of the 3D model as vertices and the adjacency relationship between local features as edges; Step S2: Obtain the geometric information of the assembly hole positions according to the fasteners assembled on the structural part, and establish the mapping relationship between the part fastener hole positions and the fasteners; Step S3: Obtain the basic information of the fasteners according to the mapping relationship between the part fastener hole positions and the fasteners obtained, and construct the part fastener hole data model; Step S4: Summarize the geometric data according to the cold extrusion area identifier and the part fastener hole data model, call geometric calculation and analysis to judge the spatial relationship between the fasteners and the cold extrusion area identifier, and identify the cold extrusion hole positions.

2. The method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 1, characterized in that The specific steps of step S1 include the following steps: Step S11: Obtain the structural part pp from the acquired STG model; Step S12: Search and obtain the cold extrusion area identifier according to the geometric graphic set nodes; Step S13: Judge whether the structural part pp has a cold extrusion area according to the cold extrusion area identifier.

3. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 2, characterized in that, The specific steps of step S2 include the following steps: Step S21: Extract the assembly relationship between the structural parts according to the STG model; Step S22: Obtain the fastener information having an assembly relationship with the structural part pp according to the assembly relationship; Step S23: Obtain the geometric information of the assembly hole positions according to the fastener information, and establish the mapping relationship between the part fastener hole positions and the fasteners.

4. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 3, characterized in that, The specific steps of step S21 include the following steps: Step S211A: Describe the name and shape information of the acquired structural parts; Step S212A: Obtain the connection relationship between the structural parts by using the double interference inspection method, and establish the adjacency model; Step S213A: Calculate the connection relationship feature set matching the structural part classification rule library according to the name and shape information of the structural parts; Step S214A: Obtain the assembly relationship between the structural parts with the matching relationship as the search space.

5. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 4, characterized in that, The specific steps of step S211A include the following steps: Step S2111A: Initialize the structural part category set C; Step S2112A: Obtain the name id of the model file corresponding to the structural part pp pp ; Step S2113A: Determine the part category c of the structural part pp pp Whether it belongs to the category set C. If not, call the shape distribution algorithm to describe the shape information of the structural part pp as a k-dimensional shape vector s pp , and establish a part descriptor <id pp , s pp >, and use the structural part pp as a new part category c pp Add it to the category set; Step S2114A: If the name id of the structural part model file pp = id qq , id qq ∈ c qq , then create a part descriptor <id qq , s qq >, where id qq is the name of the model file corresponding to part qq, and c qq is the part category of part qq; Step S2115A: Repeat step S2112A - step S2114A until all parts are traversed.

6. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 5, characterized in that, The specific steps of step S212A include the following steps: Step S2121A: Obtain the assembly body I from the structural part classification rule library, initialize the m×m-dimensional adjacency matrix G, and calculate the AABB bounding box R of the structural parts; where m is the number of parts in the to-be-identified structural part model A; Step S2122A: Select the structural part pp' from the assembly body I and initialize the set S; Step S2123A: Randomly obtain part qq from assembly I. If bounding box R pp’ ∩R qq ≠ , then add part qq to set S. R pp’ is the AABB bounding box of part pp', and R qq is the AABB bounding box of part qq; Step S2124A: For the part qq in the set S, call the octree interference checking algorithm to perform spatial interference checking on the structural part pp' and the part qq. If the checking result is contact or interference, then the adjacency matrix G pp’qq = 1; Step S2125A: Repeat step S2122A - step S2124A until all parts of the assembly body I are traversed.

7. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 6, characterized in that, The specific steps of step S213A include the following steps: Step S2131A: Initialize the matching part set Com pp ; Step S2132A: Add the structural part with the name id in the finished product model A to be recognized to the matching part set Com pp ; pp ; Step S2133A: Calculate the shape vector s of the structural part pp pp and the shape vector s of the part in the i-th category of the part category set C i for similarity; Step S2134A: Determine whether the similarity is greater than or equal to the set shape similarity threshold. If so, add all the parts in the i-th category to the matching part set Com pp .

8. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 7, characterized in that, In the step S2133A, calculate the shape vector s of the structural part pp pp and the shape vector s of the part in the i-th category of the part category set C i The formula for the similarity is as follows: ； where s pp represents the shape vector of the structural part pp, k represents the dimension of the k-dimensional shape vector of the part, and l j pp represents the j-th dimensional shape vector of the structural part pp, and l j qq represents the j-th dimensional shape vector of the part qq in the i-th category.

9. A method for identifying the cold extrusion area of a hole in a structural part fastener according to claim 8, characterized in that, The specific operation of the step S2134A is as follows: according to the set shape similarity threshold ε, if the similarity sim(s pp , s i ) ≥ ε, then all the parts in the i-th category are added to the matching part set Com pp , s i is the shape vector of the parts in the i-th category.

10. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 9, characterized in that, The specific operation of the step S214A is as follows: taking the part matching relationship as the search space, and calling the Ullmann subgraph matching algorithm to search for the subgraph matching result with the same structure as the adjacency matrix G of the assembly I in the adjacency matrix G of the finished product model A to be recognized, so as to identify the assembly relationship between the structural parts. A in the I adjacency matrix G of the assembly I, and identifying the assembly relationship between the structural parts.

11. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 3, characterized in that, The specific steps of step S21 include the following steps: Step S211B: Construct the structural part assembly relationship instance library according to the acquired STG model; Step S212B: According to the established instance library of the assembly relationship of structural parts, convert the obtained shape information of the structural parts into a k-dimensional vector, and calculate the set of neighbor vectors according to the obtained spatial neighbor characteristics between the structural parts; Step S213B: Search for a matching candidate set of the 3D model of the structural parts according to the k-dimensional vector and the set of neighbor vectors; Step S214B: According to the matching candidate set, obtain the spatial distribution aggregation of the matching structural parts, and identify the assembly relationship between the structural parts.

12. A method for identifying the cold extrusion area of the holes of a structural part fastener according to claim 11, characterized in that, The specific steps of the said Step S212B include the following steps: Step S2121B: According to the established instance library of the assembly relationship of structural parts, obtain the structural part instances, and construct the OBB bounding box of the structural parts; the structural part instances include the maximum length, maximum width, and maximum height of the structural parts; Step S2122B: Judge the spatial distribution relationship between the parts according to the interference situation of the bounding boxes, and obtain the set of neighbor vectors; Step S2123B: Repeat Step S2121B - Step S2122B until each part in the structural part model and the instance library of the assembly relationship of structural parts is traversed.

13. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 12, characterized in that, The specific steps of the said Step S213B include the following steps: Step S2131B: Coarsely filter part pp according to the set shape similarity threshold and the similarity between structural part pp and part qq to obtain the initial set; Step S2132B: Calculate the similarity of the neighbor sets between the parts in the initial set and structural part pp according to the initial set; Step S2133B: Match the initial set according to the set neighbor similarity threshold and the neighbor similarity to obtain the matching candidate set.

14. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 13, characterized in that, The specific steps of the said Step S214B include the following steps: Step S2141B: Construct an ordered set according to the size of the part neighbor set in the structural part instance; Step S2142B: Initialize set list, set Ca, set Flag, and set Tar; Step S2143B: Assign the ordered set to set list. If structural part pp is the first element of set list, assign the matching candidate set to set Ca; Step S2144B: Randomly select part qq1 from set Ca, and judge whether it meets the set criterion conditions; Step S2145B: If not satisfied, assign Ca - {qq1} to set Ca, and assign Ca pp - {qq1} to the matching candidate set Ca of part pp pp ; If the set , then select the next part qq2 in set Ca and return to step S2144B; If the set , then end the search; Ca - {qq1} and Ca pp - {qq1} are the sets obtained by removing element {qq1} from Ca and Ca pp respectively; Step S2146B: If the set criterion holds, add the structural part pp to the set Flag, and at the same time establish an ordered set list of the neighbor vector set Nei of the part pp pp of the ordered set list pp ; Step S2147B: If , then take the part set corresponding to the output set Tar as the assembly relationship, assign to the set list, assign Ca pp -{qq1} to the set Ca, and return to Step S2144B; Step S2148B: If , then assign to the set Tar, assign to the set Ca, assign list pp to the set list, and return to Step S2144B, is the set of neighbor vectors of part qq1; Step S2149B: Take the output set Tar as the assembly relationship of the matching structural parts.

15. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 1, characterized in that, The specific steps of the said Step S3 include the following steps: Step S31: According to the mapping relationship between the fastener hole positions and the fasteners, obtain the basic information of the fasteners; the basic information of the fasteners includes the fastener drawing number, fastener instance number, fastener name, fastener structure tree path, and fastener axis endpoint coordinates; Step S32: Combine the obtained basic information of the fasteners with the mapping relationship between the fastener hole positions and the fasteners to construct a part-fastener hole data model.

16. A method for identifying the cold extrusion area of the hole of a structural part fastener according to claim 15, characterized in that, The specific steps of the said Step S4 include the following steps: Step S41: Obtain the coordinate sp of the starting point of the fastener axis relative to the part coordinate system and the coordinate ep of the ending point of the fastener axis relative to the part coordinate system according to the basic information of the fasteners; Step S42: Based on the starting point coordinates sp, ending point coordinates ep of the fastener axis, and transformation matrix rm, perform matrix operations to obtain the starting point sppp in the part coordinate system and the ending point eppp in the part coordinate system; Step S43: In the part coordinate system, establish a geometric ray that extends infinitely in the starting point direction, and call the SetLineType function in the CAD secondary development interface to set the line to the StartInf mode; Step S44: Call the GetIntersect method in the CAD secondary development interface to perform an intersection operation between the geometric ray and the cold extrusion area identifier. If there are no intersecting elements, it is determined that there is no cold extrusion area in the current fastener hole; if there are intersecting elements, obtain all the point elements and store them in the point set List. The number of elements in the point set is num, and the index starts from 1; Step S45: Use the singularity theorem to judge the relationship between the identifier and the fastener axis; if the number of elements in the point set List is odd, the fastener hole is a cold extrusion area; otherwise, further judgment is made. Add the starting point sppp and ending point eppp of the fastener axis to the point set List, establish a normalized vector vec pointing from the ending point eppp to the starting point sppp, and sort the point set List along the direction from the ending point to the starting point using the projection value of the coordinates in the direction of the vector vec; Step S46: Retrieve the index k of the starting point sppp in the point set List. If the number of elements pnum = num - k from the starting point sppp to the last intersection point is even, it is determined that the fastener hole is a cold extrusion area; otherwise, the fastener hole is a non-cold extrusion area.

17. A method for identifying the cold extrusion area of a fastener hole of a structural part according to claim 16, characterized in that, It further includes Step S5: In the constructed part fastener hole data model, traverse each fastener basic information and execute Step S41 - Step S46 until all cold extrusion areas of the part are obtained.

18. A method for identifying the cold extrusion area of holes in structural part fasteners according to claim 1, characterized in that, The establishment process of the STG model in Step S1 is as follows: First, establish a vertex adjacency graph based on the topological relationship between the geometric elements of the obtained B-rep data; secondly, search for the maximum cliques in the adjacency graph and use the geometric regions corresponding to the maximum cliques as local features of the solid model; then call the statistical method to transform the shape information of the local features into feature vectors to form a feature space, and use an unsupervised learning algorithm to suppress the local features differently; finally, establish an STG model with the local features as vertices and the adjacency relationship between the local features as edges.

19. A cold extrusion area recognition system for structural part fastener holes, which is used to execute the cold extrusion area recognition method for structural part fastener holes as described in claim 1; characterized in that, It includes a search unit, an acquisition unit, a construction unit, and an identification unit; The search unit is used to judge whether the structural part has a cold extrusion area according to the searched and obtained cold extrusion area identifier; The acquisition unit is used to obtain the geometric information of the assembly hole positions according to the fasteners assembled on the structural part; The construction unit is used to obtain the fastener basic information according to the obtained geometric information of the assembly hole positions and construct a part fastener hole data model; The identification unit is used to analyze and judge the spatial relationship between the fastener and the cold extrusion area identifier according to the cold extrusion area identifier and the part fastener hole data model, and identify the cold extrusion hole positions.

20. An electronic device, characterized in that, It includes a memory and a processor; a computer program is stored on the memory; when the computer program is executed on the processor, it implements the method for identifying the cold extrusion area of the fastener hole of the structural part as described in any one of claims 1-18.

21. A computer-readable storage medium, characterized in that, A computer instruction is stored on the computer-readable storage medium; when the computer instruction is executed on the electronic device as described in claim 20, it implements the method for identifying the cold extrusion area of the fastener hole of the structural part as described in any one of claims 1-18.

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