A method, system, device, and medium for identifying cold-extruded regions of a structural part fastener hole

Abstract

The present application relates to the technical field of digital assembly design, in particular to a structure part fastener hole cold extrusion region identification method, system, device and medium; the method first searches and obtains the cold extrusion region identification, judges whether the structure part has the cold extrusion region; secondly, according to the fastener of structure part assembly, obtains the assembly hole position geometric information; then obtains the fastener basic information, constructs the part fastener hole data model; finally, according to the space relationship between the fastener and the cold extrusion region identification, the cold extrusion hole position is identified; by converting the three-dimensional fastener hole feature from implicit expression to explicit expression, then analyzing the spatial position of the fastener hole feature and the closed surface sheet of the cold extrusion region, and through accurately identifying the relationship between the fastener hole and the closed surface sheet, the identification accuracy and efficiency of the cold extrusion hole position are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of digital assembly process design, in particular, to a structure part fastener hole cold extrusion region identification method, system, device and medium. BACKGROUND

[0002] The process procedure is a production process document prepared by the process department according to design requirements, process technical requirements and quality requirements. The process procedure not only includes process information, but also production information and quality information, which guides workers to operate the specific work instructions of the specified assembly process flow, including operation instructions, processes, assembly timing, change records and other information.

[0003] At present, the process procedure is still mainly prepared manually, and the process procedure preparation work has a long cycle, and the process procedure preparation result is poor in standardization, and even some quality errors may occur. Therefore, the automatic preparation of the process procedure becomes an urgent problem in aircraft development and production, and the automatic identification of aircraft parts and features is an important factor restricting the automatic preparation and planning of the process procedure.

[0004] To improve the fatigue resistance of the structure, the cold extrusion process is one of the main measures to prolong the service life of the aircraft structure. The metal material is deformed by using strong pressure to improve the mechanical properties and surface quality of the structure part.

[0005] In the process preparation stage, the process personnel need to compare the part model with the cold extrusion region mark of the part model when identifying the cold extrusion region, and then compile the cold extrusion process requirements in the process instruction. The cold extrusion region mark is usually in the form of an irregular closed patch, which wraps as many fastener holes as possible that need to be cold extruded in the closed patch, and the closed patch is saved in the three-dimensional model of the part. Due to the large number of fastener hole positions of the aviation parts, the cold extrusion hole positions are scattered, and other situations, the closed patch does not tightly wrap a single fastener hole, and the wrapping area is large. In addition, the spatial position relationship between the fastener and the part is often used to express the fastener hole on the structure implicitly, and the actual existing three-dimensional fastener hole feature is lacking.

[0006] At present, visual identification is still one of the main methods for identifying cold extrusion structure fastener holes. In a complex space, it is very difficult to visually identify whether the fastener has an assembly relationship with the part and whether it is inside the closed patch. There may be problems such as missed identification and mistaken identification, which may cause the actual state to be inconsistent with the design state, and the visual identification method cannot meet the needs of automatic preparation and planning of the process procedure. SUMMARY

[0007] The present application aims at the low efficiency problem of visual identification of cold extrusion requirements of structural fastener holes, and proposes a structural part fastener hole cold extrusion region identification method, system, equipment and medium; the method first searches and obtains cold extrusion region identification, judges whether the structural part has a cold extrusion region; secondly, according to the fasteners assembled by the structural part, the assembly hole position geometric information is obtained; then the fastener basic information is obtained, and the part fastener hole data model is constructed; finally, according to the analysis of the spatial relationship between the fastener and the cold extrusion region identification, the cold extrusion hole position is identified; by converting the three-dimensional fastener hole feature from implicit expression to explicit expression, and then analyzing the spatial position of the fastener hole feature and the cold extrusion region closed surface sheet, the accuracy and efficiency are improved.

[0008] The present application specifically realizes the following contents:

[0009] A structural part fastener hole cold extrusion region identification method, first, according to the cold extrusion region identification obtained by searching, judges whether the structural part has a cold extrusion region; secondly, according to the fasteners assembled by the structural part, the assembly hole position geometric information is obtained; then the fastener basic information is obtained according to the obtained assembly hole position geometric information, and the part fastener hole data model is constructed; finally, according to the cold extrusion region identification, the part fastener hole data model, the spatial relationship between the fastener and the cold extrusion region identification is analyzed and judged, and the cold extrusion hole position is identified.

[0010] In order to better realize the present application, further, the structural part fastener hole cold extrusion region identification method specifically includes the following steps:

[0011] Step S1: according to the obtained STG model, the cold extrusion region identification is obtained, and it is judged whether the structural part has a cold extrusion region, the STG model is a model established by taking the local features of a three-dimensional model as vertices and the adjacency relationship between the local features as edges;

[0012] Step S2: according to the fasteners assembled by the structural part, the assembly hole position geometric information is obtained, and the mapping relationship between the part fastener hole and the fastener is established;

[0013] Step S3: according to the mapping relationship between the part fastener hole and the fastener obtained, the fastener basic information is obtained, and the part fastener hole data model is constructed;

[0014] Step S4: according to the cold extrusion region identification, the part fastener hole data model is summarized, the geometric data is called, the spatial relationship between the fastener and the cold extrusion region identification is analyzed and judged, and the cold extrusion hole position is identified.

[0015] In order to better realize the present application, further, the step S1 specifically includes the following steps:

[0016] Step S11: obtaining a structural part pp from the acquired STG model;

[0017] Step S12: searching and obtaining a cold extrusion area identifier according to a geometry set node;

[0018] Step S13: judging whether the structural part pp has a cold extrusion area according to the cold extrusion area identifier.

[0019] To better realize the present application, further, the step S2 specifically comprises the following steps:

[0020] Step S21: extracting an assembly relationship between structural parts according to the STG model;

[0021] Step S22: obtaining fastener information having an assembly relationship with the structural part pp according to the assembly relationship;

[0022] Step S23: obtaining assembly hole geometry information according to the fastener information, and establishing a mapping relationship between a part fastener hole and a fastener.

[0023] To better realize the present application, further, the step S21 specifically comprises the following steps:

[0024] Step S211A: describing the name and shape information of the obtained structural part;

[0025] Step S212A: obtaining a connection relationship between structural parts by using a double interference verification method, and establishing an adjacency model;

[0026] Step S213A: calculating a connection relationship feature set matched with a structural part classification rule library according to the name and shape information of the structural part;

[0027] Step S214A: taking a matched relationship as a search space, and obtaining an assembly relationship between structural parts.

[0028] To better realize the present application, further, the step S211A specifically comprises the following steps:

[0029] Step S2111A: initializing a structural part category set C;

[0030] Step S2112A: obtaining a name id of a model file corresponding to the structural part pp pp ;

[0031] Step S2113A: judging whether a part category c pp of the structural part pp belongs to the category set C, if not, calling a shape distribution algorithm to describe the shape information of the structural part pp as a k-dimensional shape vector s ppand a part descriptor <id pp , s pp > is established, id pp is the name of the model file corresponding to the part qq, and c pp is the part category of the part qq.

[0032] Step S2114A: if the name id qq of the model file of the structural part is id qq , and id qq ∈ c qq , a part descriptor <id qq , s qq > is established, id qq is the name of the model file corresponding to the part qq, and c pp’ is the part category of the part qq.

[0033] Step S2115A: steps S2112A to S2114A are repeated until all parts are traversed.

[0034] To better implement the present application, further, the step S212A specifically comprises the following steps:

[0035] Step S2121A: an assembly I is obtained from a structural part classification rule library, an m*m dimensional adjacency matrix G is initialized, and an AABB bounding box R of the structural part is calculated; wherein m is the number of parts in the model A of the structural part to be identified.

[0036] Step S2122A: a structural part pp' is selected from the assembly I, and a set S is initialized.

[0037] Step S2123A: a part qq is randomly obtained from the assembly I, if the bounding box R pp’ ∩R qq ≠ , the part qq is added 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.

[0038] Step S2124A: according to the parts qq in the set S, an octree interference checking algorithm is called to spatially interfere check the structural part pp' and the part qq, if the checking result is contact or interference, the adjacency matrix G pp’qq =1.

[0039] Step S2125A: steps S2122A to S2124A are repeated until all parts of the assembly I are traversed.

[0040] To better implement the present application, further, the step S213A specifically comprises the following steps:

[0041] Step S2131A: initialize the matched part set Com pp ;

[0042] Step S2132A: add the structural part with name id pp in the to-be-identified end product model A to the matched part set Com pp ;

[0043] Step S2133A: calculate the similarity of the shape vector s pp of the structural part pp with the shape vector s i of the parts in the i-th category in the part category set C;

[0044] Step S2134A: according to the set shape similarity threshold, judge whether the similarity is greater than or equal to the shape similarity threshold, if yes, add all the parts in the i-th category to the matched part set Com pp .

[0045] In order to better realize the present application, further, the formula for calculating the similarity of the shape vector s pp of the structural part pp with the shape vector s i of the parts in the i-th category in the part category set C in the step S2133A is:

[0046] ;

[0047] wherein s pp represents the shape vector of the structural part pp, k represents the dimension of the part k-dimensional shape vector, l j pp represents the j-th dimensional shape vector of the structural part pp, l j qq represents the j-th dimensional shape vector of the part qq in the i-th category.

[0048] In order to better realize the present application, further, the specific operation of the step S2134A is: according to the set shape similarity threshold ε, if the similarity sim(s pp , s i ) ≥ ε, then add all the parts in the i-th category to the matched part set Com pp , s i is the shape vector of the part in the i-th category.

[0049] In order to better realize the present application, further, the specific operation of the step S414A is: taking the part matching relationship as the search space, calling the Ullmann subgraph matching algorithm to search in the adjacency matrix G A of the to-be-identified end product model A and the adjacency matrix G IThe matching result of the subgraph with the same structure identifies the assembly relationship between the structural parts.

[0050] To better realize the present application, further, the step S21 specifically comprises the following steps:

[0051] Step S211B: constructing a structural part assembly relationship instance library according to the acquired STG model;

[0052] 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 spatial neighbor characteristics between the acquired structural parts;

[0053] Step S213B: searching for a matching candidate set of the structural part three-dimensional model according to the k-dimensional vector and the neighbor vector set;

[0054] Step S214B: acquiring the spatial distribution aggregation of the matching structural parts according to the matching candidate set, and identifying the assembly relationship between the structural parts.

[0055] To better realize the present application, further, the step S212B specifically comprises the following steps:

[0056] Step S2121B: acquiring a structural part instance and constructing an OBB bounding box of the structural part according to the constructed structural part assembly relationship instance library; the structural part instance comprises a maximum length, a maximum width and a maximum height of the structural part;

[0057] Step S2122B: judging the spatial distribution relationship between the parts according to the bounding box interference, and acquiring a neighbor vector set;

[0058] Step S2123B: repeating the step S2121B to the step S2122B until each part in the structural part model and the structural part assembly relationship instance library is traversed.

[0059] To better realize the present application, further, the step S213B specifically comprises the following steps:

[0060] Step S2131B: coarsely filtering a part pp to obtain an initial set according to a set shape similarity threshold and the similarity between the part pp and a part qq;

[0061] Step S2132B: calculating the neighbor set similarity between the parts in the initial set and the part pp according to the initial set;

[0062] Step S2133B: matching the initial set to obtain a matching candidate set according to a set neighbor similarity threshold and the neighbor similarity.

[0063] In order to better implement the present invention, further, step S214B specifically includes the following steps:

[0064] Step S2141B: constructing an ordered set according to the size of the part neighbor set in the structural part instance;

[0065] Step S2142B: Initialize the set list, set Ca, set Flag, and set Tar;

[0066] 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.

[0067] Step S2144B: Randomly select part qq1 from the set Ca and determine whether it meets the set criteria;

[0068] Step S2145B: If not satisfied, assign Ca-{qq1} to the set Ca, and assign Ca pp -{qq1} is assigned to the matching candidate set Ca of part pp pp If the collection , then select the next part qq2 in the set Ca and return to step S2144B; if the set , then the search ends; Ca-{qq1}, Ca pp -{qq1} are respectively from Ca, Ca pp The set after removing the element {qq1};

[0069] Step S2146B: If the set criteria are met, then add the structural part pp to the set Flag, and simultaneously establish the neighbor vector set Nei of the part pp pp An ordered set list pp ;

[0070] Step S2147B: If , then the parts set corresponding to the output set Tar is used as the assembly relationship, Assign to the collection list, Ca pp - Assign {qq1} to the set Ca and return to step S2144B;

[0071] Step S2148B: If , then Assign to the collection Tar, Assign to the set Ca, list pp Assign the value to the set list and return to step S2144B, is the set of neighbor vectors of part qq1;

[0072] Step S2149B: Set the output set Tar as the assembly relationship of the matched structural parts.

[0073] To better implement the present application, further, the step S3 specifically comprises the following steps:

[0074] Step S31: Obtain fastener basic information according to the mapping relationship between the fastener hole site and the fastener; the fastener basic information comprises a fastener drawing number, a fastener instance number, a fastener name, a fastener structure tree path, and fastener axis endpoint coordinates;

[0075] Step S32: Combine the obtained fastener basic information with the mapping relationship between the fastener hole site and the fastener to construct a part fastener hole data model.

[0076] To better implement the present application, further, the step S4 specifically comprises the following steps:

[0077] Step S41: Obtain the coordinates sp of the start point of the fastener axis relative to the part coordinate system and the coordinates ep of the end point of the fastener axis relative to the part coordinate system according to the fastener basic information;

[0078] Step S42: Obtain the start point sppp in the part coordinate system and the end point eppp in the part coordinate system through matrix operation according to the fastener axis start point coordinates sp, the end point coordinates ep, and the transformation matrix rm;

[0079] Step S43: Establish a geometric ray extending infinitely in the direction of the start point in the part coordinate system, and call the SetLineType function in the CAD secondary development interface to set the straight line as the StartInf mode;

[0080] Step S44: Call the GetIntersect method in the CAD secondary development interface to perform intersection operation on the geometric ray and the cold extrusion region identifier, if there is no intersection element, it is determined that the current fastener hole does not exist a cold extrusion region; if there is an intersection element, all point elements are obtained and exist in a point set List, the number of the point set is num, and the index starts from 1;

[0081] Step S45: Determine the relationship between the identifier and the fastener axis by using the singularity theorem; if the number of the point set List is odd, the fastener hole is a cold extrusion region; otherwise, further determination is performed, the start point sppp and the end point eppp of the fastener axis are added to the point set List, a normalized vector vec is established from the end point eppp to the start point sppp, and the point set List is sorted along the direction from the end point to the start point by using the projection value of the coordinates in the direction of the vector vec;

[0082] 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 an even number, the fastener hole is determined to be a cold extrusion area; otherwise, the fastener hole is a non-cold extrusion area.

[0083] In order to better implement the present invention, the method for identifying the cold extrusion area of ​​the fastener hole of a structural part further includes step S5: in the constructed part fastener hole data model, traverse the basic information of each fastener, and execute steps S41 to S46 until all the cold extrusion areas of the part are obtained.

[0084] In order to better realize the present invention, further, the establishment process of the STG model in step S1 is: first, a vertex adjacency graph is established according to the topological relationship between the geometric elements of the acquired B-rep data; secondly, the maximum clique in the adjacency graph is searched and the geometric area corresponding to the maximum clique is used as the local feature of the entity model; then, a statistical method is called to convert the shape information of the local feature into a feature vector to form a feature space, and an unsupervised learning algorithm is used to differentially suppress the local features; finally, an STG model is established with local features as vertices and the adjacency relationship between local features as edges.

[0085] Based on the above-mentioned method for identifying cold extrusion areas of fastener holes of structural parts, in order to better implement the present invention, a system for identifying cold extrusion areas of fastener holes of structural parts is further proposed, which is used to execute the above-mentioned method for identifying cold extrusion areas of fastener holes of structural parts; the system comprises a search unit, an acquisition unit, a construction unit, and an identification unit;

[0086] The search unit is used to determine whether the structural part has a cold extrusion area based on the cold extrusion area identifier searched and obtained;

[0087] The acquisition unit is used to acquire assembly hole geometry information based on fasteners assembled with structural parts;

[0088] The construction unit is used to obtain basic information of the fastener based on the acquired assembly hole geometry information and construct a part fastener hole data model;

[0089] The identification unit is used to analyze and determine the spatial relationship between the fastener and the cold extrusion area mark based on the cold extrusion area mark and the part fastener hole data model, and identify the cold extrusion hole position.

[0090] 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, an electronic device is further proposed, 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 ​​fastener holes in structural parts is implemented.

[0091] In order to better achieve the present application, further, a computer readable storage medium is provided, and the computer readable storage medium has computer instructions stored thereon; when the computer instructions are executed on the electronic device, the structural part fastener hole cold extrusion region identification method is implemented.

[0092] The present application has the following beneficial effects:

[0093] (1) The present application improves the identification accuracy and efficiency of the cold extrusion hole site by accurately identifying the relationship between the fastener hole and the closed surface sheet.

[0094] (2) The present application converts the three-dimensional fastener hole feature from implicit expression to explicit expression, and then analyzes the spatial position of the fastener hole feature and the cold extrusion region closed surface sheet, which has higher accuracy and efficiency compared with the traditional visual identification. BRIEF DESCRIPTION OF DRAWINGS

[0095] Figure 1 A structural part cold extrusion region rapid identification flowchart is provided for the present application.

[0096] Figure 2 A structural part and cold extrusion region example diagram is provided for the present application. DETAILED DESCRIPTION

[0097] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. It should be understood that the described embodiments are only a part of the embodiments of the present application, not all the embodiments, and therefore should not be regarded as limiting the scope of protection. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application.

[0098] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "provided", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0099] Example 1:

[0100] The embodiment proposes a structure part fastener hole cold extrusion region identification method. First, whether the structure part has a cold extrusion region is judged according to the searched and obtained cold extrusion region identification. Second, the assembly hole position geometric information is obtained according to the fastener of the structure part assembly. Then, the fastener basic information is obtained according to the obtained assembly hole position geometric information, and a part fastener hole data model is constructed. Finally, the spatial relationship between the fastener and the cold extrusion region identification is analyzed and judged according to the cold extrusion region identification and the part fastener hole data model, and the cold extrusion hole position is identified.

[0101] Working principle: the embodiment converts the three-dimensional fastener hole feature from implicit expression to explicit expression, and then analyzes the spatial position of the fastener hole feature and the cold extrusion region closed surface sheet. Compared with the traditional visual identification, it has higher accuracy and efficiency.

[0102] Embodiment 2:

[0103] The embodiment is based on the above-mentioned embodiment 1 and is described in the form of steps.

[0104] The structure part fastener hole cold extrusion region identification method specifically includes the following steps:

[0105] Step S1: obtaining the cold extrusion region identification according to the obtained STG model, and judging whether the structure part has a cold extrusion region.

[0106] Further, the step S1 specifically includes the following steps:

[0107] Step S11: obtaining the structure part pp from the obtained STG model;

[0108] Step S12: searching and obtaining the cold extrusion region identification according to the geometric graph set node;

[0109] Step S13: judging whether the structure part pp has a cold extrusion region according to the cold extrusion region identification.

[0110] In the step S1 of the embodiment, the STG model obtained is first to establish a vertex adjacency graph according to the topological relationship between the vertices, surfaces and other geometric elements in the B-rep data; the geometric region corresponding to the maximum team in the graph is searched and obtained as the local feature of the model; the shape information of the local feature is converted into a feature vector based on a statistical method to form a feature space, and an unsupervised learning algorithm is used for local feature difference suppression, so that the local features with similar shapes have the same code; finally, an STG model is established with the local features as the vertices and the adjacency relationship as the edges.

[0111] Step S2: obtaining the assembly hole position geometric information according to the fastener of the structure part assembly, and establishing the mapping relationship between the part fastener hole position and the fastener;

[0112] The step S2 specifically comprises the following steps:

[0113] Step S21: extracting the assembly relationship between the structural parts according to the STG model;

[0114] Step S22: obtaining fastener information having an assembly relationship with the structural part pp according to the assembly relationship;

[0115] Step S23: obtaining assembly hole geometry information according to the fastener information, and establishing a mapping relationship between the part fastener hole and the fastener.

[0116] Step S3: obtaining fastener basic information according to the mapping relationship between the part fastener hole and the fastener, and constructing a part fastener hole data model.

[0117] The step S3 specifically comprises the following steps:

[0118] Step S31: obtaining fastener basic information according to the mapping relationship between the fastener hole and the fastener; the fastener basic information includes fastener drawing number, fastener instance number, fastener name, fastener structure tree path, and fastener axis endpoint coordinates;

[0119] Step S32: combining the obtained fastener basic information with the mapping relationship between the fastener hole and the fastener, and constructing a part fastener hole data model.

[0120] Step S4: summarizing geometric data according to the cold extrusion region identifier and the part fastener hole data model, calling geometric calculation and analysis to judge the spatial relationship between the fastener and the cold extrusion region identifier, and identifying the cold extrusion hole.

[0121] The step S4 specifically comprises the following steps:

[0122] Step S41: obtaining the coordinates sp of the start point of the fastener axis relative to the part coordinate system and the coordinates ep of the end point of the fastener axis relative to the part coordinate system according to the fastener basic information;

[0123] Step S42: obtaining the start point sppp in the part coordinate system and the end point eppp in the part coordinate system by matrix operation according to the start point coordinates sp, the end point coordinates ep of the fastener axis, and the transformation matrix rm;

[0124] Step S43: establishing a geometric ray extending infinitely in the direction of the start point in the part coordinate system, and calling the SetLineType function in the CAD secondary development interface to set the straight line to the StartInf mode;

[0125] Step S44: Call the GetIntersect method of the CAD secondary development interface to perform an intersection operation on the geometric ray and the cold extrusion area identifier. If there is no intersecting element, it is determined that there is no cold extrusion area in the current fastener hole. If there is an intersecting element, all point elements are obtained and stored in the point set List. The number of point sets is num, and the index starts from 1.

[0126] Step S45: Using the singular point theorem, determine the relationship between the identifier and the fastener axis. If the number of points in the point set List is odd, the fastener hole is a cold extrusion area. Otherwise, further determination is made by adding the starting point sppp and the end point eppp of the fastener axis to the point set List, establishing a normalized vector vec pointing from the end point eppp to the starting point sppp, and using the projection value of the coordinates in the direction of the vector vec to sort the point set List along the direction from the end point to the starting point.

[0127] 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 an even number, the fastener hole is determined to be a cold extrusion area; otherwise, the fastener hole is a non-cold extrusion area.

[0128] Step S5: In the constructed part fastener hole data model, traverse the basic information of each fastener and execute steps S41 to S46 until all cold extrusion areas of the part are obtained.

[0129] Working principle: This embodiment first searches and obtains the cold extrusion area identification based on the three-dimensional digital model of the part, and determines whether the structural part has a cold extrusion area by identifying the cold extrusion area identification; secondly, the fasteners assembled with the part are used to obtain the geometric information of the assembly hole position. The assembly relationship between the parts is extracted based on the assembly digital model, the fastener information that has an assembly relationship with the part described in step one is identified, and a mapping relationship between the part fastener hole position and the fastener is established; then, based on the obtained mapping relationship between the part fastener hole position and the fastener, the basic information of the fastener is obtained, the drawing number, name, structure tree path, and axis endpoint coordinates of the fastener are obtained, and a part fastener hole data model is constructed; finally, the geometric data is summarized based on the obtained cold extrusion area identification and the obtained part fastener hole position model, and the spatial relationship between the fastener and the cold extrusion area identification is determined through geometric calculation analysis, and the basic information of the fastener hole position contained in the cold extrusion area is summarized to meet the needs of rapid identification of the cold extrusion area of ​​the part.

[0130] The rest of this embodiment is the same as that of the above-mentioned embodiment 1, and therefore will not be described in detail.

[0131] Example 3:

[0132] This embodiment is based on any one of the above embodiments 1 to 2. Figure 1 、Figure 2 The detailed description is illustrated with one specific embodiment.

[0133] Step S1: search and acquire the cold extrusion area identification of the structural part.

[0134] For the structural part pp, search the geometric set node with "cold extrusion area" on the structure tree in the three-dimensional CAD software, and screen the closed face sheet geometric elements under the node; store the geometric element node in the Object container of the secondary development interface of the three-dimensional CAD software; only provide the cold extrusion area identification method for the parts with closed face sheet geometric elements. The selected structural part and the cold extrusion area identification of the case are shown in Figure 2 The yellow area in the figure is the cold extrusion area identification that needs to be searched, and the cold extrusion hole position is identified by combining the assembly relationship after positioning the area.

[0135] Step S2: extract the assembly relationship between the parts according to the assembly model.

[0136] Extract each assembly relationship information in the assembly model, summarize the assembly relationship information involving the structural part pp, identify the corresponding fastener node according to the drawing number, and establish the mapping relationship KP={kp1, kp2, …, kpi, …, kpn} between the part fastener hole and the fastener, 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. Store the n assembly hole nodes in the Vector container of the secondary development interface of the three-dimensional CAD software. <object>Container collection.

[0137] Step S3: Constructing the part fastener hole data model.

[0138] According to the mapping relationship KP of the structural part pp, n fastener basic information ST={pn, in, name, rm, sp, ep} is obtained, wherein pn is a figure number, in is an instance number, name is a name, rm is a transformation matrix, sp is a fastener axis origin coordinate, and ep is a fastener axis end coordinate. The above information is combined with the mapping relationship KP of the structural part pp to construct a part fastener hole data model MST={ST1, ST2, ST3, …, STi, …, STn}, which expresses the attributes and geometric information of n fastener holes in the structural part pp.

[0139] Step S4: judging the spatial relationship between the fastener and the mark to identify the cold extrusion area of the part.

[0140] For the fastener basic information ST, the coordinates of the origin and the end of the fastener axis relative to the part coordinate system are obtained. According to the origin sp and the end coordinate ep of the fastener axis obtained in step S3 and the transformation matrix rm, matrix operation is performed to obtain the origin sppp=rm* sp and the end eppp = rm * ep in the part coordinate system.

[0141] In the part coordinate system, a geometric ray extending infinitely in the direction of the origin is established, and the SetLineType function in the secondary development interface of the three-dimensional CAD software is used to set the straight line to the StartInf mode.

[0142] The geometric ray and the mark are intersected by using the GetIntersect method in the secondary development interface of the three-dimensional CAD software. If there is no intersection element, it is determined that there is no cold extrusion area for the fastener hole. If there is an intersection element, all the point elements in the point set List are obtained, and the number of point sets is num, and the index starts from 1.

[0143] The singularity theorem is used to judge the relationship between the mark and the fastener axis. If the number of point sets List is odd, the fastener hole is a cold extrusion area. Otherwise, further judgment is needed. The origin sppp and the end eppp of the fastener axis are added to the point set List. A normalized vector vec is established from the end eppp to the origin sppp. The point set List is sorted along the direction from the end to the origin by using the projection value of the coordinates in the direction of the vector vec.

[0144] The index k of the origin sppp in the point set List is searched. If the number pnum =num-k of elements from the origin 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.

[0145] In the part fastener hole data model MST constructed in step S3, the n fastener basic information ST is traversed, the above judgment is performed, and all the cold extrusion areas of the part are obtained.

[0146] The rest of this embodiment is the same as any of the above-mentioned embodiments 1 and 2, and thus will not be described in detail.

[0147] Example 4:

[0148] This embodiment is based on any one of the above embodiments 1 to 3, and illustrates step S21 by using a specific embodiment.

[0149] The step S21 specifically includes the following steps:

[0150] Step S21A: Extract the assembly relationship between structural parts according to the STG model.

[0151] The step S21A specifically includes the following steps:

[0152] Step S211A: describing the name and shape information of the acquired part;

[0153] The step S211A specifically includes the following steps:

[0154] Step S2111A: Initialize the structural part category set C;

[0155] Step S2112A: Get the name id of the model file corresponding to the structural part pp pp ;

[0156] Step S2113A: Determine the part category c of the structural part pp pp Does it belong 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 create a part descriptor <id pp , s pp >, take the structural part pp as the new part category c pp Add to category collection;

[0157] 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 >, id qq is the name of the model file corresponding to part qq, c qq is the part category of part qq;

[0158] Step S2115A: repeat step S2112A-step S2114A until all parts are traversed.

[0159] Step S212A: obtain the connection relationship between parts by using the double interference inspection method, and establish an adjacency model.

[0160] The step S212A specifically includes the following steps:

[0161] 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 part; wherein m is the number of parts in the to-be-identified structural part model A;

[0162] Step S2122A: select a structural part pp' from the assembly I, and initialize a set S;

[0163] Step S2123A: randomly obtain a 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;

[0164] Step S2124A: according to the part qq in the set S, call the octree interference inspection algorithm to inspect the spatial interference between the structural part pp' and the part qq, if the inspection result is contact or interference, then the adjacency matrix G pp’qq =1;

[0165] Step S2125A: repeat step S2122A-step S2124A until all parts of the assembly I are traversed.

[0166] Step S213A: calculate the connection relationship feature set matched with the finished product installation classification rule library according to the name and shape information of the finished product;

[0167] The step S213A specifically includes the following steps:

[0168] Step S2131A: initialize the matching part set Com pp ;

[0169] 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 ;

[0170] Step S2133A: calculate the shape vector s pp The shape vector s of the part in the i-th category in the part category set C i similarity;

[0171] The specific operations of step S2133A are:

[0172] ;

[0173] Among them, s pp represents the shape vector of the structural part pp, k represents the dimension of the part k-dimensional shape vector, l j pp Represents the j-th dimension shape vector of the structural part pp, l j qq Represents the j-th shape vector of part qq in the i-th category.

[0174] Step S2134A: Based on 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 parts set Com pp .

[0175] The specific operation of step S2134A is: according to the set shape similarity threshold ε, determine 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 parts set Com pp , namely 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, c i is the set of parts of category i in the part category set C.

[0176] Step S214A: Using the matching relationship as the search space, obtain the assembly relationship.

[0177] The specific operation of step S214A is: using the part matching relationship as the search space, calling the Ullmann subgraph matching algorithm on the adjacency matrix G of the structural part model A A Search the adjacency matrix G of assembly I I The subgraphs with the same structure are matched to identify the assembly relationship between the structural parts.

[0178] The other parts of this embodiment are the same as any one of Embodiment 1-Embodiment 3 described above, and thus will not be described again.

[0179] Embodiment 5:

[0180] This embodiment is based on any one of Embodiment 1-Embodiment 4 described above, and describes step S21 in another embodiment,

[0181] The step S21 specifically includes the following steps:

[0182] Step S211B: According to the obtained STG model, a structural part assembly relationship instance library is constructed.

[0183] Step S212B: According to the constructed structural part assembly relationship instance library, the obtained structural part shape information is converted into a k-dimensional vector, and a neighbor vector set is calculated according to the spatial neighbor characteristics obtained between the structural parts.

[0184] Further, the step S212B specifically includes the following steps:

[0185] Step S2121B: According to the constructed structural part assembly relationship instance library, a structural part instance is obtained, and an OBB bounding box of the structural part is constructed; the structural part instance includes a maximum length, a maximum width, and a maximum height of the structural part pp;

[0186] Step S2122B: According to the bounding box interference condition, the spatial distribution relationship between the parts is judged, and a neighbor vector set is obtained;

[0187] Step S2123B: Steps S2121B-S2122B are repeated until each part in the structural part model and the structural part assembly relationship instance library is traversed.

[0188] Step S213B: According to the k-dimensional vector and the neighbor vector set, a matching candidate set of the structural part three-dimensional model is searched and obtained;

[0189] The step S213B specifically includes the following steps:

[0190] Step S2131B: According to the set shape similarity threshold and the similarity between the structural part pp and the part qq, the part pp is coarsely filtered to obtain an initial set;

[0191] Step S2132B: According to the initial set, the neighbor set similarity between the parts in the initial set and the structural part pp is calculated;

[0192] Step S2133B: According to the set neighbor similarity threshold and the neighbor similarity, the initial set is matched to obtain a matching candidate set.

[0193] Step S214B: Based on 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.

[0194] The step S214B specifically includes the following steps:

[0195] Step S2141B: constructing an ordered set according to the size of the part neighbor set in the structural part instance;

[0196] Step S2142B: Initialize the set list, set Ca, set Flag, and set Tar;

[0197] 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.

[0198] Step S2144B: Randomly select part qq1 from the set Ca and determine whether it meets the set criteria;

[0199] Step S2145B: If not satisfied, assign Ca-{qq1} to the set Ca, and assign Ca pp -{qq1} is assigned to the matching candidate set Ca of part pp pp ; If the collection , then select the next part qq2 in the set Ca and return to step S2144B; if the set , then the search ends; Ca-{qq1}, Ca pp -{qq1} are respectively from Ca, Ca pp The set after removing the element {qq1};

[0200] Step S2146B: If the set criteria are met, then add the structural part pp to the set Flag, and simultaneously establish the neighbor vector set Nei of the part pp pp An ordered set list pp ;

[0201] Step S2147B: If , then the parts set corresponding to the output set Tar is used as the assembly relationship, Assign to the collection list, Ca pp - Assign {qq1} to the set Ca and return to step S2144B;

[0202] Step S2148B: If , then Assign to the collection Tar, Assign to the set Ca, list pp is assigned to a set list, and step S2144B is returned, is a neighbor vector set of the part qq1;

[0203] Step S2149B: the output set Tar is the assembly relationship of the matched structure part.

[0204] The other parts of the embodiment are the same as any one of the above-mentioned embodiments 1-embodiment 4, and will not be repeated.

[0205] Embodiment 6:

[0206] The embodiment is based on any one of the above-mentioned embodiments 1-embodiment 5, and proposes a structure part fastener hole cold extrusion region identification system for executing the above-mentioned structure part fastener hole cold extrusion region identification method; comprising a searching unit, an acquisition unit, a construction unit, an identification unit;

[0207] The searching unit is used to determine whether the structure part has a cold extrusion region according to the searched and acquired cold extrusion region identifier;

[0208] The acquisition unit is used to acquire assembly hole position geometric information according to the fastener of the structure part assembly;

[0209] The construction unit is used to acquire fastener basic information according to the acquired assembly hole position geometric information, and construct a part fastener hole data model;

[0210] The identification unit is used to analyze and judge the spatial relationship between the fastener and the cold extrusion region identifier according to the cold extrusion region identifier and the part fastener hole data model, and identify the cold extrusion hole position.

[0211] The embodiment also proposes an electronic device comprising a memory and a processor; the memory stores a computer program; when the computer program is executed on the processor, the above-mentioned structure part fastener hole cold extrusion region identification method is realized.

[0212] The embodiment also proposes a computer readable storage medium, the computer readable storage medium stores computer instructions; when the computer instructions are executed on the above-mentioned electronic device, the above-mentioned structure part fastener hole cold extrusion region identification method is realized.

[0213] The other parts of the embodiment are the same as any one of the above-mentioned embodiments 1-embodiment 5, and will not be repeated.

[0214] The processor involved in the embodiments of the present application can be a chip. For example, it can 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 processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chip.

[0215] The memory involved in the embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically EPROM (EEPROM) or a flash memory. The volatile memory can be a random access memory (RAM) 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 SDRAM (ESDRAM), synchlink DRAM (SLDRAM) and direct rambus RAM (DR RAM). It should be noted that the memory of the system and method described herein is intended to include, but not limited to, these and any other suitable types of memory.

[0216] It should be understood that the size of the sequence number of the above processes does not mean the order of execution in various embodiments of the present application, and the execution order of the processes should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0217] Those skilled in the art can realize that the modules and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0218] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working process of the above-described system, device and module can refer to the corresponding process in the foregoing method embodiments, which will not be repeated here.

[0219] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of the modules is only a logical function division, and actual implementation can have another division manner, for example, a plurality of modules or components can be combined or integrated into another device, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed each other can be through some interface, indirect coupling or communication connection between devices or modules, which can be electrical, mechanical or other forms.

[0220] The modules described as separate components can or can not be physically separated, and the components displayed as modules can or can not be physical modules, that is, they can be located in one device, or can be distributed to multiple devices. According to actual needs, part or all of the modules can be selected to achieve the purpose of the present embodiment.

[0221] In addition, each functional module in each embodiment of the present application can be integrated in one device, or each module can exist physically, or two or more modules can be integrated in one device.

[0222] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by using a software program, all or part of the embodiments can be implemented 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, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center through wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium that can be accessed by a computer or data storage device including one or more servers, data centers, etc. integrated with the medium. The available medium can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, DVD), or a semiconductor medium (for example, solid state disk (SSD)) and the like.

[0223] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.< / object>

Claims

1. A method for identifying cold extrusion areas of fastener holes of structural parts, characterized in that: The following steps are involved: Step S1: obtaining a cold extrusion area identifier based on the obtained STG model to determine whether the structural part has a cold extrusion area, wherein the STG model is a model established with local features of a three-dimensional model as vertices and adjacency relationships between local features as edges; Step S2: According to the fasteners assembled on the structural parts, the geometric information of the assembly holes is obtained, and a mapping relationship between the fastener holes and the fasteners is established; Step S3: obtaining basic information of the fasteners based on the acquired mapping relationship between the fastener hole positions and the fasteners, and constructing a fastener hole data model for the parts; Step S4: Summarize the geometric data based on the cold extrusion area mark and the part fastener hole data model, call geometric calculation analysis to determine the spatial relationship between the fastener and the cold extrusion area mark, and identify the cold extrusion hole position; The STG model is established as follows: first, a vertex adjacency graph is established based on the topological relationship between the geometric elements of the acquired B-rep data; second, the maximum clique in the adjacency graph is searched and the geometric area corresponding to the maximum clique is used as the local feature of the solid model; then, the shape information of the local feature is converted into a feature vector by using a statistical method to form a feature space, and an unsupervised learning algorithm is used to differentially suppress the local features; finally, an STG model is established with local features as vertices and the adjacency relationship between local features as edges; In step S1, a structural part pp is obtained from the obtained STG model; a cold extrusion area identifier is searched and obtained according to the geometry set node, and whether the structural part pp has a cold extrusion area is determined according to the cold extrusion area identifier; Step S3 specifically includes the following steps: Step S31: acquiring basic information of the fastener according to the mapping relationship between the fastener hole position and the fastener; the basic information of the fastener includes the fastener drawing number, the fastener instance number, the fastener name, the fastener transformation matrix, and the coordinates of the fastener axis endpoints; Step S32: combining the acquired basic information of the fastener with the mapping relationship between the fastener hole position and the fastener to construct a part fastener hole data model; Step S4 specifically includes the following steps: Step S41: obtaining the coordinates sp of the starting point of the fastener axis relative to the part coordinate system and the coordinates ep of the end point of the fastener axis relative to the part coordinate system according to the basic information of the fastener; Step S42: performing matrix calculation based on the starting coordinate sp and the ending coordinate ep of the fastener axis and the transformation matrix rm to obtain the starting point sppp and the ending point eppp in the part coordinate system; Step S43: In the part coordinate system, a geometric ray extending infinitely in the starting direction is established, and the SetLineType function in the CAD secondary development interface is called to set the line to StartInf mode; Step S44: Call the GetIntersect method of the CAD secondary development interface to perform an intersection operation on the geometric ray and the cold extrusion area identifier. If there is no intersecting element, it is determined that there is no cold extrusion area in the current fastener hole. If there is an intersecting element, all point elements are obtained and stored in the point set List. The number of point sets is num, and the index starts from 1. Step S45: Using the singular point theorem, determine the relationship between the identifier and the fastener axis. If the number of points in the point set List is odd, the fastener hole is a cold extrusion area. Otherwise, further determination is made by adding the starting point sppp and the end point eppp of the fastener axis to the point set List, establishing a normalized vector vec pointing from the end point eppp to the starting point sppp, and using the projection value of the coordinates in the direction of the vector vec to sort the point set List along the direction from the end point to the starting point. 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 an even number, the fastener hole is determined to be a cold extrusion area; otherwise, the fastener hole is a non-cold extrusion area.

2. A method for identifying cold extrusion areas of fastener holes of structural parts according to claim 1, characterized in that: The step S2 specifically includes the following steps: Step S21: extracting the assembly relationship between structural parts according to the STG model; Step S22: acquiring information of fasteners having an assembly relationship with the structural part pp according to the assembly relationship; Step S23: obtaining assembly hole geometry information according to the fastener information, and establishing a mapping relationship between the part fastener hole position and the fastener.

3. The method for identifying cold extrusion areas of fastener holes of structural parts according to claim 2, characterized in that: The step S21 specifically includes the following steps: Step S211A: describing the name and shape information of the acquired structural parts; Step S212A: using a double interference inspection method to obtain the connection relationship between structural parts and establish an adjacency model; Step S213A: Calculating a connection relationship feature set that matches the structural part classification rule library based on the name and shape information of the structural part; Step S214A: Using the matching relationship as the search space, obtain the assembly relationship between the structural parts.

4. A method for identifying cold extrusion areas of fastener holes of structural parts according to claim 3, characterized in that: The step S211A specifically includes the following steps: Step S2111A: Initialize the structural part category set C; Step S2112A: Get 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 Does it belong 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 create a part descriptor <id pp , s pp >, take the structural part pp as the new part category c pp Add to category collection; 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 >, id qq is the name of the model file corresponding to part qq, c qq is the part category of part qq; Step S2115A: Repeat steps S2112A to S2114A until all parts are traversed.

5. The method for identifying cold extrusion areas of fastener holes of structural parts according to claim 4, characterized in that: The step S212A specifically includes the following steps: Step S2121A: Obtain assembly I from the structural part classification rule library, initialize an 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 structural part model A to be identified; Step S2122A: Select structural part pp' from assembly I and initialize set S; Step S2123A: Randomly obtain part qq from assembly I. If the bounding box , then add part qq to the set S, R pp’ is the AABB bounding box of part pp', R qq is the AABB bounding box of part qq; Step S2124A: For the part qq in the set S, call the octree interference check algorithm to check the spatial interference between 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 to S2124A until all parts of assembly I are traversed.

6. The method for identifying cold extrusion areas of fastener holes of structural parts according to claim 5, characterized in that: The step S213A specifically includes the following steps: Step S2131A: Initialize matching parts set Com pp ; Step S2132A: The name of the finished product model A to be identified is id pp The structural parts are added to the matching parts collection Com pp ; Step S2133A: Calculate the shape vector s of the structural part pp pp The shape vector s of the part in the i-th category in the part category set C i similarity; Step S2134A: Based on 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 parts set Com pp .

7. The method for identifying cold extrusion areas of fastener holes of structural parts according to claim 6, characterized in that: 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 part k-dimensional shape vector, l j pp Represents the j-th dimension shape vector of the structural part pp, l j qq Represents the j-th shape vector of part qq in the i-th category.

8. The method for identifying cold extrusion areas of fastener holes of structural parts according to claim 7, characterized in that: The specific operation of step S2134A is: according to the set shape similarity threshold , if the similarity sim(s pp , s i )≥ , 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.

9. The method for identifying cold extrusion areas of fastener holes of structural parts according to claim 8, characterized in that: The specific operation of step S214A is: using the part matching relationship as the search space, calling the Ullmann subgraph matching algorithm on the adjacency matrix G of the finished product model A to be identified A Search the adjacency matrix G of assembly I I The subgraphs with the same structure are matched to identify the assembly relationship between the structural parts.

10. The method for identifying cold extrusion areas of fastener holes of structural parts according to claim 2, characterized in that: The step S21 specifically includes the following steps: Step S211B: constructing a structural parts assembly relationship instance library based on the obtained STG model; Step S212B: converting the acquired structural part shape information into a k-dimensional vector based on the constructed structural part assembly relationship instance library, and calculating a neighbor vector set based on 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 set of nearest neighbor vectors; Step S214B: Based on 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.

11. A method for identifying cold extrusion areas of fastener holes of structural parts according to claim 10, characterized in that: The step S212B specifically includes the following steps: Step S2121B: obtaining a structural part instance based on the constructed structural part assembly relationship instance library, and constructing an OBB bounding box of the structural part; the structural part instance includes the maximum length, maximum width, and maximum height of the structural part; Step S2122B: Determine the spatial distribution relationship between the parts based on the bounding box interference situation and obtain a set of neighbor vectors; Step S2123B: Repeat steps S2121B to S2122B until each part in the structural part model and the structural part assembly relationship instance library is traversed.

12. A method for identifying cold extrusion areas of fastener holes of structural parts according to claim 11, characterized in that: The step S213B specifically includes the following steps: Step S2131B: Based on the set shape similarity threshold and the similarity between the structural part pp and the part qq, the part pp is coarsely filtered to obtain an initial set; Step S2132B: Based on the initial set, calculate the similarity between the parts in the initial set and the neighboring sets of the structural part pp; Step S2133B: According to the set neighbor similarity threshold and neighbor similarity, the initial set is matched to obtain a matching candidate set.

13. A method for identifying cold extrusion areas of fastener holes of structural parts according to claim 12, characterized in that: The step S214B specifically includes the following steps: Step S2141B: constructing 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 part qq1 from the set Ca and determine whether it meets the set criteria; Step S2145B: If not satisfied, assign Ca-{qq1} to the set Ca, and assign Ca pp -{qq1} is assigned to the matching candidate set Ca of part pp pp If the collection , then select the next part qq2 in the set Ca and return to step S2144B; if the set , then the search ends; Ca-{qq1}, Ca pp -{qq1} are respectively from Ca, Ca pp The set after removing the element {qq1}; Step S2146B: If the set criteria are met, then add the structural part pp to the set Flag, and simultaneously establish the neighbor vector set Nei of the part pp pp An ordered set list pp ; Step S2147B: If , then the parts set corresponding to the output set Tar is used as the assembly relationship, Assign to the collection list, Ca pp - Assign {qq1} to the set Ca and return to step S2144B; Step S2148B: If , then Assign to the collection Tar, Assign to the set Ca, list pp Assign the value to the set list and return to step S2144B, is the set of neighbor vectors of part qq1; Step S2149B: Tar the output set to the assembly relationship of the matching structural parts.

14. The method for identifying cold extrusion areas of fastener holes of structural parts according to claim 1, characterized in that: The method further includes step S5: in the constructed part fastener hole data model, traversing basic information of each fastener, and executing steps S41 to S46 until all cold extrusion areas of the part are obtained.

15. A cold extrusion area recognition system for fastener holes of structural parts, used to execute the cold extrusion area recognition method for fastener holes of structural parts according to claim 1; characterized in that: It includes search unit, acquisition unit, construction unit and recognition unit; The search unit is used to determine whether the structural part has a cold extrusion area based on the cold extrusion area identifier searched and obtained; The acquisition unit is used to acquire assembly hole geometry information based on fasteners assembled with structural parts; The construction unit is used to obtain basic information of the fastener based on the acquired assembly hole geometry information and construct a part fastener hole data model; The identification unit is used to analyze and determine the spatial relationship between the fastener and the cold extrusion area mark based on the cold extrusion area mark and the part fastener hole data model, and identify the cold extrusion hole position.

16. An electronic device, characterized in that: It comprises a memory and a processor; a computer program is stored on the memory; when the computer program is executed on the processor, the method for identifying the cold extrusion area of ​​the fastener hole of a structural part according to any one of claims 1 to 14 is implemented.

17. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions; when the computer instructions are executed on the electronic device according to claim 16, the method for identifying the cold extrusion area of ​​the fastener hole of a structural part according to any one of claims 1 to 14 is implemented.

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