A method, system and device for repairing topological structure of vehicle body model

Abstract

The present invention discloses a method, system and device for repairing the topological structure of a car body model, and belongs to the technical field of simulation model pre-processing. Existing car body model repair schemes take a lot of time and are prone to omissions, thereby affecting the repair accuracy of the three-dimensional model of the car body. A method for repairing the topological structure of a car body model of the present invention analyzes the geometric features of the car body model and obtains topological error data based on the topological features of the car body model during the creation process; then, based on the topological error data, the car body model can be accurately repaired, so that the surface of the car body model is coherent and has no redundant facets, thereby obtaining a car body simulation model suitable for computational fluid dynamics simulation, thereby achieving automatic, efficient and accurate simplified processing of the car body model, improving the repair accuracy of the car body model, and greatly improving the repair efficiency, which is conducive to the promotion and use of the car body model repair scheme.

Description

Technical Field

[0001] The invention relates to a method, system and equipment for repairing the topological structure of a vehicle body model, and belongs to the technical field of simulation model pre-processing. Background Art

[0002] Before the computational fluid dynamics simulation is performed on the 3D model of the vehicle body, the 3D model of the vehicle body needs to be pre-processed to simplify the 3D model, reduce the amount of calculation and improve the simulation accuracy. The pre-processing mainly deletes unnecessary geometric details inside the model, usually only retaining the part of the vehicle body surface that contacts the external fluid and air, that is, the external connection surface and the body surface of the 3D model of the vehicle body, to ensure that the simulation focuses on the air flow outside the vehicle body and the pressure distribution on the body surface.

[0003] At present, the simplification of the body 3D model is usually done by engineers screening the input body 3D model point by point and face by face to identify the type of error in each place; then, the designer adopts the corresponding manual repair strategy to modify each error based on experience; and after checking and confirming that it meets the standards, the body simulation model can be output. Therefore, the above pre-processing scheme will cause the repair process of the body 3D model to take a lot of time and effort, and manual repair is prone to omissions, and it is impossible to be objective and accurate at all times, which affects the repair accuracy of the body 3D model and is not conducive to the promotion and use of the body model repair scheme.

[0004] The information disclosed in this Background Art is only for understanding the background of the inventive concept and therefore it may include information that does not constitute the prior art. Summary of the invention

[0005] In response to the above problem or one of the above problems, an object of the present invention is to provide a method for repairing the topological structure of a car body model. By constructing a model reading unit, a topological structure error identification unit, and a topological structure error repair unit, the geometric features of the car body model are analyzed, and based on the topological features of the car body model during the creation process, topological error data is obtained; then, the car body model can be accurately repaired to make the surface of the car body model coherent and without redundant faces, so as to obtain a car body simulation model suitable for computational fluid dynamics simulation, thereby realizing automatic, efficient and accurate simplification of the car body model and improving the repair accuracy of the car body model.

[0006] In response to the above problem or one of the above problems, the second purpose of the present invention is to provide a method, system and equipment for repairing the topological structure of a car body model. Based on the topological features of the car body model during the creation process, the geometric information and topological information of the car body model are processed to obtain topological error data, and based on the topological error data, the errors in the model topological structure are repaired. Compared with traditional manual repair, it can always be objective and accurate and not affected by subjective factors. Therefore, while ensuring the simplified processing accuracy of the car body model, it greatly improves the repair efficiency, saves expensive labor costs, and is conducive to the promotion and use of car body model repair solutions.

[0007] To achieve one of the above purposes, the first technical solution of the present invention is:

[0008] A method for repairing a topological structure of a vehicle body model includes the following contents:

[0009] The vehicle body model is read through a pre-built model reading unit, and the geometric features of the vehicle body model are analyzed to obtain the geometric information and topological information of the vehicle body model;

[0010] Using the pre-built topological structure error recognition unit, based on the topological features of the car body model during the creation process, the geometric information and topological information are processed to obtain topological error data;

[0011] A pre-built topology structure error repair unit is used to repair the body model based on the topology error data, so that the surface of the body model is coherent and has no redundant faces, thereby obtaining a repaired body simulation model.

[0012] The present invention constructs a model reading unit, a topological structure error recognition unit, and a topological structure error repair unit to analyze the geometric features of the car body model, and obtains topological error data based on the topological features of the car body model during the creation process; then the car body model can be accurately repaired to make the surface of the car body model coherent and without redundant faces, so as to obtain a car body simulation model suitable for computational fluid dynamics simulation. Therefore, automatic, efficient and accurate simplified processing of the car body model can be achieved, thereby improving the repair accuracy of the car body model, saving time and effort, and the solution is scientific, reasonable and feasible.

[0013] Furthermore, the method for repairing the topological structure of a car body model of the present invention processes the geometric information and topological information of the car body model based on the topological features of the car body model during the creation process, thereby obtaining topological error data, and repairing errors in the topological structure of the model based on the topological error data. Compared with traditional manual repair, it can always be objective and accurate and not be affected by subjective factors. Therefore, while ensuring the simplified processing accuracy of the car body model, it greatly improves the repair efficiency, saves expensive labor costs, and is conducive to the promotion and use of car body model repair solutions.

[0014] As the preferred technical measures:

[0015] The method of reading the body model through the pre-built model reading unit and parsing the geometric features of the body model to obtain the geometric information and topological information of the body model is as follows:

[0016] Read the car body model to be processed;

[0017] Analyze the geometric features of the car body model to obtain vertices, edges, faces and their corresponding connection information;

[0018] Process vertices, edges, faces and their corresponding connection information to obtain geometric information and topological information;

[0019] Geometric information includes nodes, edges, surfaces, and volume elements;

[0020] Topological information includes volume element types, adjacency relationships, and boundary conditions.

[0021] As the preferred technical measures:

[0022] The method of obtaining topological error data by using the pre-built topological structure error recognition unit and processing the geometric information and topological information based on the topological features of the body model during the creation process is as follows:

[0023] Determine the type of topological error based on the topological features of the car body model during creation;

[0024] The topological error types include at least duplicate faces, invalid faces, intersecting faces and gaps;

[0025] According to the topology error type, set the detection benchmark information;

[0026] The detection reference information is divided into detection reference information of repeated surfaces, detection reference information of invalid surfaces, detection reference information of intersecting surfaces and detection reference information of gaps;

[0027] Based on the detection benchmark information, the geometric information and topological information are detected to obtain repeated surface data, invalid surface data, intersecting surface data and gap data;

[0028] The duplicate surface data, invalid surface data, intersecting surface data and gap data are coupled to obtain topological error data.

[0029] As the preferred technical measures:

[0030] The topology error type is a duplicate face. According to the duplicate face, the method for setting the detection benchmark information is as follows:

[0031] Repeated faces are the same or similar faces that appear in the vehicle body model, including faces with overlapping positions and faces with similar shapes;

[0032] Overlapping surfaces are two or more overlapping surfaces that occupy the same spatial position. The detection benchmark information is that the positions, boundary lines and vertices of the two surfaces in the vehicle body model are consistent. Similar-shaped surfaces are two patches with similar geometric shapes and heights. The detection benchmark information is the tolerance value that can characterize the similarity of the shapes of the two patches.

[0033] Or / and, the topology error type is an invalid surface. According to the invalid surface, the method for setting the detection benchmark information is as follows:

[0034] Invalid faces are auxiliary faces left over from the design process, redundant faces generated due to modeling errors, or faces caused by precision loss during data conversion, including non-functional faces, fragmented faces, and isolated faces.

[0035] Non-functional faces are faces that do not contribute to the characterization of the structural integrity of the vehicle body. Their detection benchmark information is faces that only connect isolated points or boundary edges; fragmented faces are faces whose patch size is so small that they have no practical meaning. Their detection benchmark information is the area threshold. When the area of ​​a patch is less than the area threshold, the patch is a fragmented face; isolated faces are independent faces that are not connected to the vehicle body model. They are useless fragments generated during the modeling process. Their detection benchmark information is faces with boundary edges and isolated points.

[0036] As the preferred technical measures:

[0037] Intersecting surfaces are overlapping patches generated during the combination design, modification or optimization process. The detection reference information is two patches with an intersection area. When the intersection area is not empty and is not just the overlap area of ​​edges or vertices, it is an intersecting surface.

[0038] Or / and, the gap is a gap in the car body model caused by discontinuous geometric structure or missing topological connection, and its detection reference information is the midpoint distance between adjacent boundary edges.

[0039] As the preferred technical measures:

[0040] Based on the detection benchmark information of the repeated surface, the geometric information and topological information are detected to obtain the repeated surface data as follows:

[0041] Step 11: Import the geometric and topological information, traverse all edges, and identify all multiple edges;

[0042] Multiple edges are edges that are shared by three or more faces at the same time;

[0043] Step 12: According to the multiple edges, traverse all faces, read the edge information of each face, and identify the faces surrounded by multiple edges;

[0044] Step 13, based on the faces surrounded by multiple edges, identify the faces that have multiple multiple edges and also have boundary edges and normal edges, and obtain the position coincidence faces;

[0045] Step 14: Based on the geometric information and topological information, all faces are traversed and the tolerance value between any two faces is calculated to determine the shape similarity of the two faces, so as to obtain faces with similar shapes.

[0046] Step 15: Summarize the overlapping faces and faces with similar shapes to obtain duplicate face data;

[0047] Or / and, based on the detection benchmark information of the invalid surface, the geometric information and topological information are detected to obtain the invalid surface data as follows:

[0048] Step 21: Import the geometric information and topological information, traverse all vertices, identify all isolated points; traverse all edges, identify all boundary edges; and traverse all faces to obtain isolated faces;

[0049] Boundary edges are edges that belong to only one face or to a boundary; isolated points are isolated points of a topological structure in the car body model;

[0050] Step 22: Based on isolated points and boundary edges, traverse all faces, read the point and edge information of each face, identify the faces surrounded by boundary edges, and obtain several boundary faces and faces with isolated points, i.e., non-functional faces.

[0051] Step 23: Calculate the area of ​​each face and compare it with the area threshold. If the area of ​​the face is smaller than the area threshold, the face is considered as a fine face.

[0052] Step 24: Summarize isolated faces, non-functional faces and fragmented faces to obtain invalid face data.

[0053] As the preferred technical measures:

[0054] Based on the detection reference information of the intersection surface, the geometric information and topological information are detected to obtain the intersection surface data as follows:

[0055] Step 31: Import geometric information and topological information, divide the vehicle body into different areas, and obtain N different topological sets;

[0056] Step 32, traverse all faces in N different topological sets respectively, and then use Boolean intersection operation to calculate any two faces to obtain the intersection operation result;

[0057] Step 33, according to the intersection operation result, obtain several groups of two intersecting face patches;

[0058] The two intersecting patches are patches whose intersection result is not empty, and the intersection is not a set of patches with common edges or common vertices of the two patches;

[0059] Step 34, storing several groups of two intersecting face patches into an intersecting face set to obtain intersecting face data;

[0060] Alternatively or alternatively, based on the gap detection reference information, the geometric information and topological information are detected to obtain the gap data as follows:

[0061] Step 41, based on the geometric information and topological information, traverse all edges and identify all boundary edges;

[0062] Step 42, for each boundary edge, calculate the midpoint distance between adjacent boundary edges;

[0063] Step 43, mark the adjacent boundary edges whose midpoint distance is greater than 0 to obtain boundary mark edges;

[0064] In step 44, the area encircled by the boundary marker edge is regarded as a gap, thereby obtaining gap data.

[0065] As the preferred technical measures:

[0066] The method of repairing the body model based on the topology error data using the pre-built topology error repair unit is as follows:

[0067] Obtain topological error data, including duplicate surface data, invalid surface data, intersecting surface data and gap data;

[0068] Based on the repeated face data, the repeated faces in the vehicle body model are merged, and the unique face patch is retained to obtain the first vehicle body model;

[0069] On the basis of the first vehicle body model, isolated points and invalid surfaces are deleted according to the invalid surface data to obtain a second vehicle body model;

[0070] On the basis of the second vehicle body model, based on the intersection surface data, the intersection surface is deleted to obtain a third vehicle body model;

[0071] Based on the third vehicle body model, the gap is repaired according to the gap data and the gap threshold, which includes the following contents:

[0072] When the distance between the midpoints of adjacent boundary edges is less than the gap threshold, the corresponding boundary edges are merged;

[0073] When the distance between the midpoints of adjacent boundary edges is greater than or equal to the gap threshold, a new patch needs to be generated to fill the gap so that the surface of the body model remains coherent, thereby obtaining a fourth body model, namely, a body simulation model.

[0074] To achieve one of the above purposes, the second technical solution of the present invention is:

[0075] A vehicle body model topology structure repair processing system includes a model reading module, a topology structure error recognition module, a topology structure error processing module and a topology structure error repair module:

[0076] The model reading module is used to read the body model, analyze the geometric features of the body model, and obtain the geometric information and topological information of the body model;

[0077] A topological structure error recognition module is used to process geometric information and topological information based on the topological features of the car body model during the creation process to obtain topological error data;

[0078] A topology error processing module is used to process topology error data and generate topology repair data;

[0079] The topology structure error repair module is used to repair the body model based on the topology repair data, so that the surface of the body model is coherent and has no redundant faces, and a repaired body simulation model is obtained.

[0080] The car body model topology structure repair system of the present invention, by setting a model reading module, a topology structure error recognition module, a topology structure error processing module and a topology structure error repair module, processes the geometric information and topology information of the car body model based on the topological features of the car body model during the creation process, thereby obtaining topological error data, and repairs errors in the model topology structure based on the topological error data. Compared with traditional manual repair, it can always be objective and accurate and not be affected by subjective factors. Therefore, while ensuring the simplified processing accuracy of the car body model, it greatly improves the repair efficiency, saves expensive labor costs, and is conducive to the promotion and use of car body model repair solutions.

[0081] To achieve one of the above purposes, the third technical solution of the present invention is:

[0082] A vehicle body model topology structure repair processing device, comprising:

[0083] one or more processors;

[0084] A storage device for storing one or more programs;

[0085] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned method for repairing the topological structure of a vehicle body model.

[0086] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0087] The present invention constructs a model reading unit, a topological structure error recognition unit, and a topological structure error repair unit to analyze the geometric features of the car body model, and obtains topological error data based on the topological features of the car body model during the creation process; then the car body model can be accurately repaired to make the surface of the car body model coherent and without redundant faces, so as to obtain a car body simulation model suitable for computational fluid dynamics simulation. Therefore, automatic, efficient and accurate simplified processing of the car body model can be achieved, thereby improving the repair accuracy of the car body model, saving time and effort, and the solution is scientific, reasonable and feasible.

[0088] Furthermore, the present invention processes the geometric information and topological information of the body model based on the topological features of the body model during the creation process, thereby obtaining topological error data, and repairs errors in the model's topological structure based on the topological error data. Compared with traditional manual repair, the present invention can always be objective and accurate and is not affected by subjective factors. Therefore, while ensuring the simplified processing accuracy of the body model, it greatly improves the repair efficiency, saves expensive labor costs, and is conducive to the promotion and use of body model repair solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] Figure 1 A schematic diagram of a process flow of a method for repairing a topological structure of a vehicle body model according to the present invention;

[0090] Figure 2 Another schematic flow chart of the method for repairing the topological structure of a vehicle body model according to the present invention. DETAILED DESCRIPTION

[0091] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0092] On the contrary, the present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention as defined by the claims. Further, in order to make the public have a better understanding of the present invention, some specific details are described in detail in the following detailed description of the present invention. Those skilled in the art can fully understand the present invention without the description of these details.

[0093] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention pertains. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0094] like Figure 1 As shown, the first specific embodiment of the method for repairing the topological structure of a vehicle body model of the present invention is as follows:

[0095] A method for repairing a topological structure of a vehicle body model includes the following contents:

[0096] The vehicle body model is read through a pre-built model reading unit, and the geometric features of the vehicle body model are analyzed to obtain the geometric information and topological information of the vehicle body model;

[0097] Using the pre-built topological structure error recognition unit, based on the topological features of the car body model during the creation process, the geometric information and topological information are processed to obtain topological error data;

[0098] A pre-built topology structure error repair unit is used to repair the body model based on the topology error data, so that the surface of the body model is coherent and has no redundant faces, thereby obtaining a repaired body simulation model.

[0099] A second specific embodiment of the method for repairing the topological structure of a vehicle body model of the present invention:

[0100] A method for repairing a topological structure of a vehicle body model comprises the following steps:

[0101] Step 1: read the body model through a pre-built model reading unit, and obtain the geometric information and topological information of the body model;

[0102] Step 2: Using a pre-built topological structure error recognition unit, the geometric information and topological information are processed to obtain topological error data;

[0103] Step 3, using a pre-built topology structure error processing unit to generate topology repair data based on the topology error data;

[0104] Step 4: Use the pre-built topology structure error repair unit to repair the body model based on the topology repair data to obtain a repaired body model.

[0105] like Figure 2 As shown, the third specific embodiment of the method for repairing the topological structure of a vehicle body model of the present invention is as follows:

[0106] A method for repairing a topological structure of a vehicle body model comprises a model reading stage, a topological structure error recognition stage, and a topological structure error repair stage.

[0107] In this embodiment, the model reading stage includes the following contents:

[0108] First, obtain a car body model to be repaired, then use algorithmic models or commercial software to identify and load the basic geometric components of the car body model, such as nodes, edges, faces and bodies, and then obtain the geometric and topological information of these geometric components, including the overall size of the model, the connection relationship between each component, the distribution of the facets, etc. The main purpose of this stage is to prepare the model data for subsequent topological structure analysis and error detection.

[0109] In this embodiment, the topology structure error identification stage includes the following contents:

[0110] During the construction process of the car body model, topological errors may occur due to various reasons. Classifying and identifying these errors ensures the effectiveness of the subsequent repair process. Topological error types include duplicate faces, invalid faces, intersecting faces, and gaps.

[0111] Duplicate faces are multiple nearly identical faces that appear in a model, which may be unintentionally generated during the design or conversion process. This type of error increases the complexity of the model, affects the calculation efficiency, and may also cause calculation errors in subsequent analysis. Duplicate faces are divided into overlapping positions and similar shapes.

[0112] Coincident faces are faces that completely overlap, and their positions, boundaries, and vertices in the model are exactly the same. In this case, two or more faces in the model actually occupy the same spatial position.

[0113] Similar-shaped faces refer to two or more faces with highly similar or almost identical geometric shapes. Such faces may only be slightly offset or partially overlapped. These faces are slightly different in position in space, but most of their areas overlap and are difficult to distinguish with the naked eye. In this case, it is necessary to set a tolerance for similar shapes to automatically detect such faces.

[0114] Invalid surfaces refer to those surfaces that do not affect the final function or performance of the product and do not meet the design intent. These surfaces may be auxiliary surfaces left over from the design process, redundant surfaces generated due to modeling errors, or surfaces caused by precision loss during data conversion. Invalid surfaces are further divided into non-functional surfaces, fragmented surfaces, and isolated surfaces.

[0115] Non-functional faces are faces that do not contribute to the structural integrity and actual function of the vehicle body. Such faces may only connect isolated points or boundary edges, and may be connected to other non-functional faces. In order to detect non-functional faces, it is usually necessary to traverse and identify them one by one through an iterative method to ensure that all useless redundant faces are deleted.

[0116] Fine faces are faces whose size is so small that they have no practical significance. By setting an area threshold, faces whose area is smaller than this area threshold can be defined as fine faces. Such faces may be caused by the model being segmented too finely or with too many details. The value of .

[0117] Isolated faces are independent faces that are not connected to the rest of the car body model. Such faces are usually useless fragments generated during the modeling process. All edges are boundary edges and all vertices are isolated points.

[0118] Intersecting surfaces refer to surfaces where different geometric components may intersect in a complex car body model. For example, the faces generated during the combination design, modification or optimization process may overlap with each other. The appearance of intersecting surfaces in the model may cause structural errors, geometric overlap, boundary errors and other problems. In the process of identifying intersecting surfaces, it is necessary to calculate the intersection area between two surfaces. If the area is not empty and is not just the overlapping area of ​​edges or vertices, it is an intersecting surface.

[0119] Gaps are spaces in a model caused by discontinuous geometry or missing topological connections. These gaps destroy the overall connectivity of the model and result in ineffective connections between different components. Gaps are usually created by removing closed subsets in topology, which can be straight lines, curves, or other closed subsets.

[0120] In this embodiment, the topology structure error repair phase includes the following contents:

[0121] 1) In order to detect duplicate faces, we first build an algorithm for detecting duplicate faces, as shown below:

[0122] In the car body model, multiple edges refer to an edge that is shared by three or more faces at the same time. is a geometric object, such as a polygon or polyhedron, whose vertex set is , the edge set is .

[0123] If the edge and edge Exists on edge set Zhongqie , then it is called and is a multiple edge. is a vertex set The two vertices in .

[0124] Secondly, we build a repair algorithm for duplicate faces, which includes the following steps:

[0125] Step 1: Import the model, traverse all edges, and identify all multiple edges.

[0126] Step 2: traverse all faces and read the edge information of each face to identify faces surrounded by multiple edges.

[0127] Step 3: Identify faces that have multiple polyedges but also contain boundary edges and normal edges.

[0128] Step 4: Merge duplicate faces, retain unique faces, and delete redundant faces.

[0129] 2) In order to realize automatic detection of invalid faces, we first build an algorithm for detecting invalid faces, as shown below:

[0130] If and only if the edge When it belongs to only one face or to a boundary, the edge is the boundary edge.

[0131] Set It is a topological space A subset of if there is a point , so that the point exist If there are no other points in the neighborhood of For collection isolated point.

[0132] Secondly, construct an invalid surface repair algorithm, which includes the following steps:

[0133] Step 1: Import the model, traverse all vertices, and identify all isolated points; at the same time, traverse all edges and identify all boundary edges.

[0134] Step 2: traverse all faces, read the point and edge information of each face, and identify the faces surrounded by boundary edges.

[0135] Step 3: traverse all faces surrounded by the boundary edges and calculate the area of ​​each face. If the area of ​​the face is less than the area threshold , then mark the face, thereby obtaining the invalid face.

[0136] In step 4, isolated points and invalid faces are detected and deleted one by one to ensure that the model structure has no redundant faces.

[0137] 3) In order to realize the automatic detection of intersecting surfaces, we first build an algorithm for detecting intersecting surfaces, as shown below:

[0138] Set the polyhedron in the model to , whose face set is Each side It can be represented as a set of boundary and interior points. , if and only if their intersection If the intersection is not empty, and the set of their common edges or common vertices is not the set of their common edges, then the two faces are intersecting faces.

[0139] Secondly, construct an algorithm for repairing intersecting surfaces, which includes the following steps:

[0140] Step 1: Import the car body model and divide it into different areas to obtain N different sets.

[0141] Step 2: traverse all faces in N different sets respectively, and then use the Boolean intersection operation to calculate every two faces. If the operation result is not empty, the two faces are stored in the intersection face set.

[0142] In the third step, the detected intersecting faces are checked and deleted one by one to ensure that there are no redundant faces in the model structure.

[0143] 4) In order to detect the gap, we first build an algorithm for detecting the gap, as shown below:

[0144] Let the gap be S, which is a closed subset of the topological space X, that is, S is closed in the topological space X; the topological space X is not connected to the gap S, that is, after removing the gap S, the topological space X is divided into two or more disconnected parts. Specifically, after the topological space X and the gap S are divided, multiple connected branches will be generated , resulting in the splitting of the topological space X into two or more disconnected regions. The gap S can be represented as a line, a curve, or a more complex closed subset.

[0145] Secondly, construct a gap repair algorithm, which includes the following steps:

[0146] Step 1, traverse all edges and identify all boundary edges.

[0147] Step 2: For each boundary edge, calculate the midpoint distance between adjacent boundary edges.

[0148] In step 3, the gap threshold J is set to 5 mm. When the distance between the midpoints is less than the gap threshold, the corresponding boundary edges are merged. When the distance between the midpoints is greater than or equal to the gap threshold, it indicates that the gap width is large, and new facets need to be generated to fill it in order to ensure the overall coherence of the model.

[0149] A specific embodiment of the vehicle body model topology structure repair processing system of the present invention:

[0150] A vehicle body model topology structure repair processing system includes a model reading module, a topology structure error recognition module, a topology structure error processing module and a topology structure error repair module:

[0151] The model reading module is used to read the body model, analyze the geometric features of the body model, and obtain the geometric information and topological information of the body model;

[0152] A topological structure error recognition module is used to process geometric information and topological information based on the topological features of the car body model during the creation process to obtain topological error data;

[0153] A topology error processing module is used to process topology error data and generate topology repair data;

[0154] The topology error repair module is used to repair the body model based on the topology repair data, so that the surface of the body model is coherent and has no redundant faces, and the final body simulation model is obtained.

[0155] A specific embodiment of applying the present invention to repair a certain automobile body model:

[0156] The method of the present invention is used to systematically identify and repair the topological structure errors of a certain automobile body model, thereby improving the accuracy and completeness of the body model, thereby laying a foundation for subsequent simulation calculations, which includes the following contents:

[0157] First, the original car body model is imported into the commercial processing software ANSA. Through its built-in functional modules, the commercial processing software can read and parse the model's geometric information (nodes, edges, surfaces, volume elements) and topological information (element type, adjacency, boundary conditions) for subsequent processing. Importing the model through the commercial processing software ensures that all necessary geometric data, including vertices, edges, faces and their corresponding connection information, are obtained. The purpose of this is to provide data support for the subsequent topological error identification and repair steps.

[0158] Common topological errors in automobile body models include duplicate faces, invalid faces, intersecting faces and gaps. The method of the present invention detects these errors and classifies them for further processing.

[0159] In this embodiment, the method for detecting and repairing duplicate surfaces is as follows:

[0160] Duplicate faces are unnecessary extra faces in a model, usually caused by accidentally creating two or more nearly identical faces during the modeling process. The presence of duplicate faces not only increases model complexity, but may also cause calculation errors in subsequent analysis.

[0161] Duplicate faces are divided into overlapping faces and similar faces. If two or more faces completely overlap, their boundaries and vertices are consistent, and they occupy the same spatial position, then these two or more faces are overlapping faces. If the positions of two or more faces may not completely overlap, but the geometric properties of the shapes are very similar or consistent, then these two or more faces are similar faces.

[0162] The detection method of duplicate faces is as follows:

[0163] ① Input the geometric and topological information of the model.

[0164] ② For each pair of adjacent faces, calculate the Hausdorff distance and preliminarily screen out candidate faces with similar geometric shapes. The point set is ,noodle The point set is , Hausdorff distance The calculation formula is as follows:

[0165]

[0166] in, Point Set The point in Point Set The point in is the supremum function, is the infimum function.

[0167] like When it is less than 1mm, the shapes of the two surfaces overlap.

[0168] ③ For geometrically similar candidate faces, further calculate the angle between each adjacent edge to generate a boundary angle sequence. Compare the boundary angle sequences of two candidate faces. If the difference in each angle in the sequence is within 3 degrees, the two candidate faces are considered to be highly consistent in boundary angle, thus determining that the two candidate faces are repeated faces with similar shapes.

[0169] ④Output the duplicate face set.

[0170] The method to repair duplicate faces is as follows:

[0171] ① According to the aforementioned duplicate face detection method, faces with a Hausdorff distance of less than 1 mm are determined as overlapping faces. For each set of overlapping faces, the face farthest from the model center is retained, and other overlapping redundant faces are deleted.

[0172] ② For candidate faces with a Hausdorff distance less than 5 mm, calculate the boundary angle sequence. If the difference in each angle in the sequence is within 3 degrees, the two faces are judged to be highly similar in shape. Calculate the distance between each face and the center point of the model, retain only the similar face with the farthest distance from the center point, and delete the remaining similar faces.

[0173] ③After the deletion operation, check the repaired boundary connection relationship to ensure that there are no breakpoints and isolated edges.

[0174] In this embodiment, the method for detecting and repairing invalid surfaces is as follows:

[0175] Invalid surfaces are surfaces that do not participate in the final product structure or function, which may be caused by design errors or precision loss in data conversion. These invalid surfaces include non-functional surfaces, fragmented surfaces, and isolated surfaces.

[0176] Non-functional surfaces have no practical use in the function and structure of the car body and usually contain isolated points and boundary edges. The model needs to be optimized by iteratively detecting and deleting these surfaces.

[0177] Fine surfaces are surfaces whose area is smaller than the set area threshold s. Such surfaces usually have no significant structural or functional significance.

[0178] An isolated face is a face that is not connected to the rest of the model. All of its edges are boundary edges and all of its points are isolated points.

[0179] The detection method of invalid faces is as follows:

[0180] ① Input the geometric and topological information of the model.

[0181] ② Traverse all vertices and edges in the model. If a vertex is not connected to any edge, it is marked as an isolated point; if an edge is only connected to one face, it is marked as a boundary edge.

[0182] ③ For each face, check whether its vertices and edges exist in the isolated point set or the boundary edge set. If any vertex or edge in the face belongs to the isolated point set or the boundary edge set, the face is marked as a non-functional face.

[0183] ④Finally, calculate the area of ​​the face. If the face consists of three vertices, directly use the cross product method to calculate the area. If it is an irregular polygonal face, decompose the face into several triangles, calculate the area of ​​each triangle separately and sum them up.

[0184] The calculation formula of the cross product method is as follows:

[0185]

[0186]

[0187]

[0188] in, They are the XYZ axis coordinates of the first vertex among the three vertices; They are the XYZ axis coordinates of the second vertex among the three vertices; They are respectively the XYZ axis coordinates of the third vertex of the three vertices.

[0189] When the calculated area is less than , it is marked as fine noodles.

[0190] ⑤Output invalid face set.

[0191] The method to repair the invalid surface is as follows:

[0192] ① Delete invalid faces, isolated faces and fragmented faces.

[0193] ② After the deletion operation, check the repaired boundary connection relationship to ensure that there are no breakpoints and isolated edges.

[0194] In this embodiment, the method for detecting and repairing the intersecting surface is as follows:

[0195] Intersecting surfaces usually refer to the overlapping areas caused by different geometric bodies overlapping each other in space in complex car body design. This situation is often seen in combination design or optimization. If two faces intersect in space and the intersection part is not their common edge or common vertex, it is determined to be an intersecting surface.

[0196] The detection method of intersecting surfaces is as follows:

[0197] ① Input the geometric and topological information of the model.

[0198] ② Based on mesh patches, the car body model is divided into multiple areas, and the faces within the area are divided into different sets to ensure the accuracy of model processing.

[0199] ③ Perform Boolean intersection operations on the faces in each spatial region to detect intersecting faces. The expression for the face set in is as follows:

[0200]

[0201] For a face set, detect all faces in it pairwise Kneading noodles The intersection of , performs the following Boolean operations:

[0202]

[0203] in is the intersection area of ​​the two faces in three-dimensional space. If the intersection is not empty and the intersection is not their common edge or common vertex, the face Kneading noodles Mark as intersecting faces.

[0204] ④Output the intersection face set.

[0205] The repair method of the intersecting surface is as follows:

[0206] ① Obtain Intersection information, retain the parts of the two faces that are not related to the intersection, separate the intersecting parts from the main face, and if the area of ​​the resulting face is less than , then delete the redundant small patches and reduce unnecessary topological structures.

[0207] ② When redefining boundary relationships, first mark and identify the old and new boundaries, and clarify the geometric features and topological relationships of each edge. Then, adjust the connection of the new boundary points based on the geometric position to ensure that they are seamlessly connected to the main model. Insert transition surfaces when necessary to achieve smooth boundary transitions and ensure the consistency of model topology and geometry.

[0208] In this embodiment, the method for detecting and repairing the gap is as follows:

[0209] A gap is a space between two or more parts of a model that causes the model's connectivity to change and is not suitable as a structurally complete geometry. A gap can be a line, curve, or complex closed subset.

[0210] The gap detection method is as follows:

[0211] ① Input the geometric and topological information of the model.

[0212] ② Traverse each edge and determine whether it is a boundary edge. The expression of the boundary edge is as follows:

[0213]

[0214] in, is an endpoint of the boundary edge, and its coordinates are ;

[0215] is the other end point of the boundary edge, and its coordinates are .

[0216] ③For each boundary edge, calculate the coordinates of its midpoint and midpoint coordinates The calculation formula is as follows:

[0217]

[0218] in, For the border edge The midpoint coordinates of .

[0219] ④Output gap set.

[0220] The method to repair the gap is as follows:

[0221] ① For each set of boundary edges, extract all vertices and generate a closed set of boundary edges to generate the gap boundary. This set represents the boundary of the gap.

[0222] ② Identify the geometric properties of adjacent faces, such as curvature, normal vector, etc., gradually insert new faces, and extend the adjacent faces along the boundary to the gap boundary, so that the new faces are naturally connected to the surrounding faces. Use interpolation or interpolation fitting methods to smooth the extended part to ensure seamless transition, so as to obtain a repaired car body simulation model.

[0223] Therefore, the method in this embodiment comprehensively optimizes the automobile body model through strict identification and repair steps, thereby greatly reducing the topological errors in the model and ensuring the accuracy of the structural and geometric information.

[0224] An embodiment of a device applying the method of the present invention:

[0225] An electronic device comprising:

[0226] one or more processors;

[0227] A storage device for storing one or more programs;

[0228] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned method for repairing the topological structure of a vehicle body model.

[0229] A computer medium embodiment using the method of the present invention:

[0230] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned method for repairing the topological structure of a vehicle body model.

[0231] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, and computer program products. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, optical storage, etc.) containing computer-usable program codes.

[0232] The present application is described by flowcharts or / and block diagrams of the methods, devices (systems), and computer program products of the embodiments of the present application. It should be understood that each process or / and block in the flowchart or / and block diagram and the combination of the processes or / and blocks in the flowchart or / and block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart or / and block diagram. Figure 1 Process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0233] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 Process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0234] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 Process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0235] The unit in this application is an object that objectively describes the morphological structure with the help of physical or virtual expressions. The object is not equal to the object and is not limited to physical and virtual. It can be a data processing function, software program, processing mode, usage method, operation method, workflow, application process, electronic hardware, circuit module, processing system, system imitation or simulation object.

[0236] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field can still modify or replace the specific implementation methods of the present invention with equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for repairing the topological structure of a vehicle body model, characterized in that: Includes the following: The vehicle body model is read through a pre-built model reading unit, and the geometric features of the vehicle body model are analyzed to obtain the geometric information and topological information of the vehicle body model; Using the pre-built topological structure error recognition unit, based on the topological features of the car body model during the creation process, the geometric information and topological information are processed to obtain topological error data; The pre-built topology structure error repair unit is used to repair the body model based on the topology error data, so that the body model surface is coherent and has no redundant patches, and a repaired body simulation model is obtained, which includes the following contents: Obtain topological error data, including duplicate surface data, invalid surface data, intersecting surface data and gap data; Based on the repeated face data, the repeated faces in the vehicle body model are merged, and the unique face patch is retained to obtain the first vehicle body model; On the basis of the first vehicle body model, isolated points and invalid surfaces are deleted according to the invalid surface data to obtain a second vehicle body model; On the basis of the second vehicle body model, based on the intersection surface data, the intersection surface is deleted to obtain a third vehicle body model; Based on the third vehicle body model, the gap is repaired according to the gap data and the gap threshold, which includes the following contents: When the distance between the midpoints of adjacent boundary edges is less than the gap threshold, the corresponding boundary edges are merged; When the distance between the midpoints of adjacent boundary edges is greater than or equal to the gap threshold, a new patch needs to be generated to fill the gap so that the surface of the body model remains coherent, thereby obtaining a fourth body model, namely, a body simulation model.

2. A method for repairing a topological structure of a vehicle body model according to claim 1, characterized in that: The method of reading the body model through the pre-built model reading unit and parsing the geometric features of the body model to obtain the geometric information and topological information of the body model is as follows: Read the car body model to be processed; Analyze the geometric features of the car body model to obtain vertices, edges, faces and their corresponding connection information; Process vertices, edges, faces and their corresponding connection information to obtain geometric information and topological information; Geometric information includes nodes, edges, surfaces, and volume elements; Topological information includes volume element types, adjacency relationships, and boundary conditions.

3. A method for repairing a topological structure of a vehicle body model according to claim 1, characterized in that: The method of obtaining topological error data by using the pre-built topological structure error recognition unit and processing the geometric information and topological information based on the topological features of the body model during the creation process is as follows: Determine the type of topological error based on the topological features of the car body model during creation; The topological error types include at least duplicate faces, invalid faces, intersecting faces and gaps; According to the topology error type, set the detection benchmark information; The detection reference information is divided into detection reference information of repeated surfaces, detection reference information of invalid surfaces, detection reference information of intersecting surfaces and detection reference information of gaps; Based on the detection benchmark information, the geometric information and topological information are detected to obtain repeated surface data, invalid surface data, intersecting surface data and gap data; The duplicate surface data, invalid surface data, intersecting surface data and gap data are coupled to obtain topological error data.

4. A method for repairing a topological structure of a vehicle body model as claimed in claim 3, characterized in that: The topology error type is a duplicate face. According to the duplicate face, the method for setting the detection benchmark information is as follows: Repeated faces are the same or similar faces that appear in the vehicle body model, including faces with overlapping positions and faces with similar shapes; Overlapping surfaces are two or more overlapping surfaces that occupy the same spatial position. The detection benchmark information is that the positions, boundary lines and vertices of the two surfaces in the vehicle body model are consistent. Similar-shaped surfaces are two patches with similar geometric shapes and heights. The detection benchmark information is the tolerance value that can characterize the similarity of the shapes of the two patches. Or / and, the topology error type is an invalid surface. According to the invalid surface, the method for setting the detection benchmark information is as follows: Invalid faces are auxiliary faces left over from the design process, redundant faces generated due to modeling errors, or faces caused by precision loss during data conversion, including non-functional faces, fragmented faces, and isolated faces. Non-functional faces are faces that do not contribute to the characterization of the structural integrity of the vehicle body. Their detection benchmark information is faces that only connect isolated points or boundary edges; fragmented faces are faces whose patch size is so small that they have no practical meaning. Their detection benchmark information is the area threshold. When the area of ​​a patch is less than the area threshold, the patch is a fragmented face; isolated faces are independent faces that are not connected to the vehicle body model. They are useless fragments generated during the modeling process. Their detection benchmark information is faces with boundary edges and isolated points.

5. A method for repairing a topological structure of a vehicle body model according to claim 4, characterized in that: Intersecting surfaces are overlapping patches generated during the combination design, modification or optimization process. The detection reference information is two patches with an intersection area. When the intersection area is not empty and is not just the overlap area of ​​edges or vertices, it is an intersecting surface. Or / and, the gap is a gap in the car body model caused by discontinuous geometric structure or missing topological connection, and its detection reference information is the midpoint distance between adjacent boundary edges.

6. A method for repairing a topological structure of a vehicle body model according to claim 5, characterized in that: Based on the detection benchmark information of the repeated surface, the geometric information and topological information are detected to obtain the repeated surface data as follows: Step 11: Import the geometric and topological information, traverse all edges, and identify all multiple edges; Multiple edges are edges that are shared by three or more faces at the same time; Step 12: According to the multiple edges, traverse all faces, read the edge information of each face, and identify the faces surrounded by multiple edges; Step 13, based on the faces surrounded by multiple edges, identify the faces that have multiple multiple edges and also have boundary edges and normal edges, and obtain the position coincidence faces; Step 14: Based on the geometric information and topological information, all faces are traversed and the tolerance value between any two faces is calculated to determine the shape similarity of the two faces, so as to obtain faces with similar shapes. Step 15: Summarize the overlapping faces and faces with similar shapes to obtain duplicate face data; Or / and, based on the detection benchmark information of the invalid surface, the geometric information and topological information are detected to obtain the invalid surface data as follows: Step 21: Import the geometric information and topological information, traverse all vertices, identify all isolated points; traverse all edges, identify all boundary edges; and traverse all faces to obtain isolated faces; Boundary edges are edges that belong to only one face or to a boundary; isolated points are isolated points of a topological structure in the car body model; Step 22: Based on isolated points and boundary edges, traverse all faces, read the point and edge information of each face, identify the faces surrounded by boundary edges, and obtain several boundary faces and faces with isolated points, i.e., non-functional faces. Step 23: Calculate the area of ​​each face and compare it with the area threshold. If the area of ​​the face is smaller than the area threshold, the face is considered as a fine face. Step 24: Summarize isolated faces, non-functional faces and fragmented faces to obtain invalid face data.

7. A method for repairing a topological structure of a vehicle body model according to claim 6, characterized in that: Based on the detection reference information of the intersection surface, the geometric information and topological information are detected to obtain the intersection surface data as follows: Step 31: Import geometric information and topological information, divide the vehicle body into different areas, and obtain N different topological sets; Step 32, traverse all faces in N different topological sets respectively, and then use Boolean intersection operation to calculate any two faces to obtain the intersection operation result; Step 33, according to the intersection operation result, obtain several groups of two intersecting face patches; The two intersecting patches are patches whose intersection result is not empty, and the intersection is not a set of patches with common edges or common vertices of the two patches; Step 34, storing several groups of two intersecting face patches into an intersecting face set to obtain intersecting face data; Alternatively or alternatively, based on the gap detection reference information, the geometric information and topological information are detected to obtain the gap data as follows: Step 41, based on the geometric information and topological information, traverse all edges and identify all boundary edges; Step 42, for each boundary edge, calculate the midpoint distance between adjacent boundary edges; Step 43, mark the adjacent boundary edges whose midpoint distance is greater than 0 to obtain boundary mark edges; In step 44, the area encircled by the boundary marker edge is regarded as a gap, thereby obtaining gap data.

8. A vehicle body model topology structure repair processing system, characterized in that: It includes model reading module, topology error identification module, topology error processing module and topology error repair module: The model reading module is used to read the body model, analyze the geometric features of the body model, and obtain the geometric information and topological information of the body model; A topological structure error recognition module is used to process geometric information and topological information based on the topological features of the car body model during the creation process to obtain topological error data; A topology error processing module is used to process topology error data and generate topology repair data; The topology error repair module is used to repair the body model based on the topology repair data, so that the body model surface is coherent and has no redundant patches, and obtains a repaired body simulation model, which includes the following contents: Obtain topological error data, including duplicate surface data, invalid surface data, intersecting surface data and gap data; Based on the repeated face data, the repeated faces in the vehicle body model are merged, and the unique face patch is retained to obtain the first vehicle body model; On the basis of the first vehicle body model, isolated points and invalid surfaces are deleted according to the invalid surface data to obtain a second vehicle body model; On the basis of the second vehicle body model, based on the intersection surface data, the intersection surface is deleted to obtain a third vehicle body model; Based on the third vehicle body model, the gap is repaired according to the gap data and the gap threshold, which includes the following contents: When the distance between the midpoints of adjacent boundary edges is less than the gap threshold, the corresponding boundary edges are merged; When the distance between the midpoints of adjacent boundary edges is greater than or equal to the gap threshold, a new patch needs to be generated to fill the gap so that the surface of the body model remains coherent, thereby obtaining a fourth body model, namely, a body simulation model.

9. A vehicle body model topology repair processing device, characterized in that: It includes: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement a vehicle body model topology repair processing method as described in any one of claims 1-7.

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