Multi-connectivity supported connected domain division method based on LBM discrete velocity model

Abstract

The invention discloses a connected domain division method supporting multiple connectivity based on an LBM discrete velocity model, and relates to the technical field of computer-aided engineering, and the method comprises the steps: marking all grid points as full connection points or non-full connection points; performing connected domain numbering on the full connection points and the non-full connection points through a breadth-first search method, storing numbered lattice points and corresponding connected domain numbers to a lattice point connected domain number recording system, and storing a merging relationship among different connected domains to a connected domain numbering system; merging the connected domain numbers in the connected domain number system to obtain a target connected domain number; and updating the connected domain numbers of the grid points in the grid point connected domain number recording system according to the target connected domain numbers to complete connected domain division. According to the method, the connected domains can be efficiently and robustly divided in the three-dimensional geometric models with different qualities, and the requirements of complex engineering scenes are met.

Description

Technical Field

[0001] The present application relates to the field of computer-aided engineering technology, and in particular to a method for partitioning a connected domain supporting multiple connectivity levels based on an LBM discrete velocity model. Background Art

[0002] In the field of modern engineering simulation and computer-aided engineering (CAE), the connected domain division of three-dimensional geometric models is the core link of many applications, such as automobile simulation and digital core simulation. These applications require accurate connectivity analysis of complex three-dimensional geometric models to ensure that subsequent numerical simulations and engineering calculations can accurately reflect physical phenomena. However, the quality of three-dimensional geometric models in reality varies, including high-precision watertight geometric models and low-quality "dirty" geometric models (such as three-dimensional scanning data). Therefore, a connected domain division method that can adapt to geometric models of different qualities is needed to meet complex and changing engineering needs.

[0003] Currently, some connected domain partitioning methods divide the connected domain by defining fixed connectivity rules (such as eight-connectivity or twenty-four-connectivity). These methods show good results when processing high-quality geometric models.

[0004] However, most existing methods can only handle the case of a single degree of connectivity and cannot flexibly adapt to geometric models of different qualities. Given a set of spatial geometric points with known connection relationships, in terms of the method of dividing the connected point set, similar technologies currently lack a search method for connected point sets (connected domains) that supports different degrees of connectivity. The quality of three-dimensional geometric models in real production scenarios varies. Conventional searches for connected point sets are easily affected by cracks and damage in the geometry, and the division results of the connected point set often do not match the intuitive geometric connected areas. Different connectivity constraint levels (connectivity) options should be provided for the quality of three-dimensional geometric models to adapt to complex and changing production scenarios. Graph-based search algorithms generally need to store all nodes and edges of the graph when searching for connected point sets. This approach has high computational and storage overheads and is difficult to meet the efficiency requirements in production scenarios. Therefore, how to efficiently and robustly divide connected domains in three-dimensional geometric models of different qualities to meet the needs of engineering simulation has become an urgent problem to be solved.

[0005] The above contents are only used to assist in understanding the technical solution of the present application and do not constitute an admission that the above contents are prior art. Summary of the invention

[0006] The purpose of this application is to provide a connected domain partitioning method supporting multiple connectivity degrees based on the LBM discrete velocity model, aiming to solve the technical problem of how to efficiently and robustly partition connected domains in three-dimensional geometric models of different qualities to meet the needs of engineering simulation.

[0007] To achieve the above object, the present application proposes a method for partitioning a connected domain supporting multiple connectivity degrees based on an LBM discrete velocity model, the method comprising: Mark all grid points as fully connected points or non-fully connected points; The connected domains of the fully connected points and the non-fully connected points are numbered by a breadth-first search method, the numbered grid points and the corresponding connected domain numbers are saved in a grid point connected domain numbering recording system, and the merging relationship between different connected domains is saved in a connected domain numbering system; Merging the connected domain numbers in the connected domain numbering system to obtain a target connected domain number; The grid point connected domain number in the grid point connected domain number recording system is updated according to the target connected domain number to complete the connected domain division.

[0008] In addition, to achieve the above purpose, the present application also proposes a connected domain partitioning device supporting multiple connectivity degrees based on an LBM discrete velocity model, the device comprising: A grid point marking module is used to mark all grid points as fully connected points or non-fully connected points; A connected domain numbering module is used to perform connected domain numbering on the fully connected points and the non-fully connected points by a breadth-first search method, save the numbered grid points and the corresponding connected domain numbers to a grid point connected domain numbering recording system, and save the merging relationship between different connected domains to a connected domain numbering system; A connected domain merging module, used for merging the connected domain numbers in the connected domain numbering system to obtain a target connected domain number; The numbering updating module is used to update the grid connected domain number in the grid connected domain number recording system according to the target connected domain number to complete the connected domain division.

[0009] In addition, to achieve the above-mentioned purpose, the present application also proposes a connected domain partitioning device supporting multiple connectivity based on an LBM discrete velocity model, the device comprising: a memory, a processor, and a computer program stored on the memory and executable on the processor, the computer program being configured to implement the steps of the connected domain partitioning method supporting multiple connectivity based on an LBM discrete velocity model as described above.

[0010] In addition, to achieve the above-mentioned purpose, the present application also proposes a storage medium, which is a computer-readable storage medium, and a computer program is stored on the storage medium. When the computer program is executed by a processor, the steps of the connected domain partitioning method supporting multiple connectivity based on the LBM discrete velocity model as described above are implemented.

[0011] In addition, to achieve the above-mentioned purpose, the present application also provides a computer program product, which includes a computer program, and when the computer program is executed by a processor, it implements the steps of the connected domain partitioning method supporting multiple connectivity based on the LBM discrete velocity model as described above.

[0012] One or more technical solutions proposed in this application have at least the following technical effects: First, the grid configuration is selected according to the actual application scenario, and the discrete velocity directions are determined according to the grid configuration, and all grid points are marked as fully connected points or non-fully connected points according to the discrete velocity directions. This step ensures the flexibility and robustness of the connected domain division, can adapt to geometric models of different qualities, and avoids the influence of geometric cracks and damage on the division results. Then, the connected domains of fully connected points and non-fully connected points are numbered by the breadth-first search method, and the numbered grid points and the corresponding connected domain numbers are saved to the grid connected domain numbering record system, and the merging relationship between different connected domains is saved to the connected domain numbering system. This process utilizes the efficiency of breadth-first search, which can quickly traverse all connected grid points, and at the same time, by recording the merging relationship, the accuracy of the connected domain division is ensured. Then, the connected domain numbers in the connected domain numbering system are merged to obtain the target connected domain number. This step ensures the continuity and uniqueness of all connected domain numbers through the merging operation, avoids number jumps and redundancy, and thus ensures the integrity of the connected domain division. Finally, the grid connected domain number in the grid connected domain number record system is updated according to the target connected domain number to complete the connected domain division. This step ensures that the connected domain numbers of all grid points are consistent with the final connected domain division results, provides accurate connected domain information for subsequent engineering simulation and analysis, and ensures the accuracy and completeness of the connected domain division. Through this series of steps, the present application can efficiently and robustly divide connected domains in three-dimensional geometric models of different qualities to meet the needs of complex engineering scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0014] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0015] Figure 1 A flowchart diagram of a method for partitioning a connected domain supporting multiple connectivity degrees based on an LBM discrete velocity model is provided in Embodiment 1 of the present application; Figure 2 A schematic diagram of a lattice configuration commonly used in the lattice Boltzmann method provided in Example 1 of the method for partitioning a connected domain supporting multiple connectivity based on the LBM discrete velocity model of this application; Figure 3 A schematic diagram of connectivity requirements of two adjacent points under three connectivity degrees provided in Example 1 of the method for partitioning a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model of this application; Figure 4 A schematic diagram of geometric crack dredging and isolation under different connectivity levels provided in Example 1 of the method for partitioning a connected domain supporting multiple connectivity levels based on the LBM discrete velocity model of this application; Figure 5 A schematic diagram of fully connected points and non-fully connected points provided in Example 1 of a method for partitioning a connected domain supporting multiple connectivity degrees based on an LBM discrete velocity model of the present application; Figure 6 A schematic diagram of a connected domain search process for all connected points provided in Example 1 of a connected domain partitioning method supporting multiple connectivity degrees based on an LBM discrete velocity model of the present application; Figure 7 A schematic diagram of a connected domain search process for non-fully connected points provided in Example 1 of a connected domain partitioning method supporting multiple connectivity degrees based on an LBM discrete velocity model of the present application; Figure 8 A schematic diagram of the connection of cracks on a car model and grid points near the cracks provided in Example 1 of the method for partitioning a connected domain supporting multiple connectivity degrees based on an LBM discrete velocity model of the present application; Fig. 9 A schematic diagram comparing the failure and success of the division of the vehicle's internal and external connected domains according to the first embodiment of the method for dividing a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model of the present application; Fig.10 A schematic diagram of a flow chart of a connected domain number merging operation in a connected domain numbering system provided in Embodiment 1 of a connected domain partitioning method supporting multiple connectivity degrees based on an LBM discrete velocity model of the present application; Fig.11 A schematic diagram of a result of a three-times connected domain number merging operation provided in Embodiment 1 of a connected domain partitioning method supporting multiple connectivity degrees based on an LBM discrete velocity model of the present application; Fig.12 A flow chart of Embodiment 2 of the method for partitioning a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model of the present application is provided; Fig.13 A schematic diagram showing a comparison between actual search results and expected search results of a connected domain when the connectivity is 2, provided in Embodiment 2 of the connected domain partitioning method supporting multiple connectivity based on the LBM discrete velocity model of the present application; Fig.14 A schematic diagram of a search result of a car geometric connected domain provided in Example 2 of a connected domain partitioning method supporting multiple connectivity degrees based on an LBM discrete speed model of this application; Fig.15 This is a schematic diagram of the module structure of a connected domain partitioning device supporting multiple connectivity degrees based on an LBM discrete velocity model according to an embodiment of the present application; Fig.16 Schematic diagram of the device structure of the hardware operating environment involved in the method for partitioning a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model in an embodiment of the present application.

[0016] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0017] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0018] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0019] In the field of modern computer-aided engineering, the connected domain division of three-dimensional geometric models is crucial for applications such as automotive simulation and digital core simulation, but existing methods are mostly designed for high-quality geometric models and are difficult to adapt to low-quality or "dirty" data. Current technologies mainly use fixed connectivity rules, which cannot flexibly cope with geometric models of different qualities, and conventional search methods are easily affected by geometric cracks and damage, resulting in inaccurate results. In order to improve adaptability, it is necessary to provide different levels of connectivity constraints to adapt to various production scenarios, and optimize the search algorithm based on graph theory to reduce computing and storage overhead to meet the efficiency requirements in practical applications.

[0020] The main solution of the embodiment of the present application is: first, determine the grid configuration and the corresponding discrete velocity direction according to the actual application scenario, and then mark the grid points as fully connected or non-fully connected according to the discrete velocity direction to adapt to different models and avoid the influence of geometric defects; then use breadth-first search to number the connected domains of these points, and save the results and merging relationships to the system to ensure the accuracy and efficiency of the division; then merge the connected domain numbers to ensure that the numbers are continuous and unique, and eliminate jumps and redundancy; finally, update the connected domain numbers of the grid points according to the merged target connected domain numbers to complete the entire connected domain division process.

[0021] It should be noted that the execution subject of the embodiments of the present application may be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device capable of realizing the above functions, a Windows computer, a Linux computer, a computer system, etc. The present embodiment and the following embodiments are described below taking a computer system as an example.

[0022] Based on this, the embodiment of the present application provides a method for partitioning a connected domain supporting multiple connectivity based on an LBM discrete velocity model. Figure 1 , Figure 1 This is a flow chart of the first embodiment of the method for partitioning a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model of the present application.

[0023] In this embodiment, the method for partitioning a connected domain supporting multiple connectivity based on the LBM discrete velocity model includes steps S10 to S40: Step S10: Mark all grid points as fully connected points or non-fully connected points.

[0024] It should be noted that the grid point refers to the regular grid points into which the calculation area is divided in the lattice Boltzmann method. Each grid point represents a tiny area of ​​the fluid and is used to simulate the behavior of the fluid.

[0025] Discrete velocity directions refer to the discrete directions used to describe particle migration in the lattice Boltzmann method. In three-dimensional space, commonly used lattice configurations include D3Q19 and D3Q27: D3Q19: Each lattice point has 19 discrete velocity directions, including 6 orthogonal directions, 12 diagonal directions, and 1 stationary direction. D3Q27: Based on D3Q19, 8 diagonal directions of the cube are added, with a total of 27 discrete velocity directions. These discrete velocity directions define the possible connection relationship between lattice points and are the basis for judging connectivity.

[0026] Connectivity refers to whether there is a direct or indirect connection between two grid points. Specifically, if two grid points meet the connectivity conditions in all discrete velocity directions within a given angle range (i.e., there are no geometric obstructions or other restrictions), then the two grid points are considered to be connected. Connectivity is determined by checking the connection relationship of the grid points in the discrete velocity direction. Connectivity determination is the core of connected domain partitioning, which determines whether the grid points belong to the same connected domain.

[0027] Connectivity refers to the connectivity constraint when judging whether two grid points belong to the same connected point set (connected domain). We set the connectivity to be divided into levels by the angle range covered by the connected grid directions: the lower the connectivity level, the smaller the angle range covered by the relative connected grid directions between two adjacent points, and the two points can be considered connected and belong to the same connected domain; the higher the connectivity level, the higher the connectivity level, the more adjacent points need to be connected in almost all relative grid directions to be considered connected.

[0028] In this embodiment, three levels of connectivity are defined, indicating that the discrete velocity direction angle ranges that need to be considered when judging whether a grid point is connected are 0°, 45°, and 90°, respectively, and the strength of the connectivity constraint increases in sequence. Assuming that the D2Q9 discrete model is used ( Figure 2 (a) in Figure 1 is used to determine the connectivity of these two adjacent grid points. Under different connectivity conditions: (1) Connectivity 0: Two grid points are considered connected if they can only be connected in one discrete velocity direction (covering an angle range of 0°). Figure 3 As shown in (a), the grid points In the direction The adjacent grid points along the direction are marked as connectable. In the opposite direction are also marked as connectable, then the two grid points are considered connected and belong to the same connected domain; extended to the three-dimensional D3Q19 grid configuration ( Figure 2 In (b)), if the grid points In the direction The adjacent grid points along the direction are marked as connectable. In the opposite direction , the two grid points are considered connected. (2) Connectivity 1: The two grid points are connected in all directions within a 45° range of a discrete velocity direction (covering an angle range of 45°). Figure 3 As shown in (b), the grid points In the direction and the direction within the 45° angle range are all marked as connectable, and their directions Neighboring grid points in the direction Meet the direction And the direction within 45° are marked as connectable, then the grid points , connected, belonging to the same connected domain; extended to the three-dimensional D3Q19 lattice configuration ( Figure 2 In (b)), if the grid points In the direction The connection is marked on the top and the direction is within 45° are marked as connectable, and the point is along the direction The adjacent grid points Meet the direction And the direction within 45° are marked as connectable, then the grid points , (3) Connectivity 2: Two grid points are connected in all directions within 90° of a discrete velocity direction (covering an angle range of 90°). Figure 3 As shown in (c) in the figure, the grid points In the direction and the directions within the 90° angle range are all marked as connectable, and their directions Neighboring grid points in the direction Meet the direction And the direction within 45° are marked as connectable, then the grid points , connected, belonging to the same connected domain; similarly, extended to the three-dimensional D3Q19 lattice configuration ( Figure 2 (b) in the figure, the grid points In the direction And the direction within 90° are marked as connectable, and the point is along the direction The adjacent grid points Meet the direction And the direction within 90° are marked as connectable, then the grid points , Connectivity.

[0029] A point on a Cartesian grid Draw the discrete velocity direction of the lattice configuration and specify the point Along discrete directions The nearest grid point reached is Neighboring points , for example, for the D2Q9 configuration, the point There are 8 adjacent points For two adjacent points and If there is no obstruction on their connecting line (for example, there is no geometric obstruction), mark the points separately. of direction, point of Direction (i.e. in the opposite direction of the

[0030] Please refer to Figure 2 , Figure 2 A schematic diagram of a lattice configuration commonly used in the LBM (Lattice Boltzmann Method) method provided in Embodiment 1 of the method for partitioning a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model of this application is shown in the figure. The figure shows two lattice configurations. Figure 2 (a) is the D2Q9 configuration in two-dimensional space. Figure 2 (b) is the D3Q19 configuration in three-dimensional space. In the D2Q9 configuration, the central grid point is labeled 0, and there are 8 neighboring grid points around it, labeled 1 to 8, representing the discrete velocities of the particle along 8 directions in two-dimensional space. These directions include horizontal, vertical, and two diagonal directions. The neighboring points in each direction are connected to the central point 0, indicating the possible migration of the particle in these directions. In the D3Q19 configuration, the central grid point is also labeled 0, and there are 18 neighboring grid points around it, labeled 1 to 18, representing the discrete velocities of the particle along 19 directions in three-dimensional space, including 6 orthogonal directions (parallel to the coordinate axis), 12 oblique directions (parallel to the diagonal of the coordinate plane), and the center point itself (indicating that the particle remains stationary). These discrete velocity directions define the connection relationship between the grid points and are the basis for judging connectivity when simulating fluid behavior.

[0031] Please refer to Figure 3 , Figure 3 The schematic diagram of the connectivity requirements of two adjacent points under three connectivity degrees provided in the first embodiment of the method for partitioning a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model of this application corresponds to connectivity degree 0, connectivity degree 1 and connectivity degree 2 respectively. In the case of connectivity degree 0, the two points marked as A and B in the figure are connected only in a straight line direction (such as Figure 3 In the case of connectivity 1, points A and B need to be marked as connectable in all discrete velocity directions within 45° of a discrete velocity direction (e.g. Figure 3 In connectivity 2, points A and B need to be marked as connectable in all discrete velocity directions within 90° of a discrete velocity direction (e.g. Figure 3 (c) in Figure 1), which is the most stringent connectivity condition, requiring that two points can be connected in almost all relative directions. These schematic diagrams show that as the connectivity increases, the requirements for connectivity between adjacent points also increase, thus adapting to three-dimensional models of different geometric qualities and achieving accurate division of connected domains.

[0032] Please refer to Figure 4 , Figure 4 The schematic diagram of geometric crack dredging and isolation under different connectivity degrees is provided in Example 1 of the method for partitioning a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model of this application. In the case of connectivity degree 1 ( Figure 4 (a) in the figure), based on the connectivity judgment of the D2Q9 lattice configuration, due to , The two points are in the direction and the two adjacent directions within the 45° range, direction And the two adjacent directions within the 45° range can be connected, so it is determined , The two points are connected, and the red arrow in the figure indicates the connection path, which means that under the lower connectivity requirement, the existence of cracks allows the grid points inside and outside the vehicle to connect through the cracks, resulting in unsuccessful division of the connected domain inside and outside the vehicle, which may increase the computational overhead. In the case of connectivity 2 ( Figure 4 (b) in the figure), based on the connectivity judgment of the D2Q9 lattice configuration, , The two points do not meet the condition that the speed directions within the relative 90° range can be connected, so the two points are judged to be disconnected. Therefore, the points in the area cannot be connected through the geometric gap. The area is divided into two connected domains with blue circular points and green diamond points, realizing the correct division of the grid points inside and outside the vehicle in different connected domains, so that only the grid points outside the vehicle can be selected for numerical simulation of the flow field during calculation, thereby eliminating unnecessary calculations of the grid points inside the vehicle. This schematic diagram shows that by adjusting the connectivity, the results of the connected domain division can be effectively controlled to adapt to different engineering simulation requirements and improve calculation efficiency and accuracy of results.

[0033] Fully connected points are grid points that are marked as connectable in all discrete velocity directions (the discrete velocity directions are determined by the grid configuration used), and any two adjacent fully connected points must simultaneously satisfy connectivity 0, 1, and 2. Fully connected points are of special significance in connected domain search because they can quickly divide the connected domain through breadth-first search (BFS).

[0034] Non-fully connected points are grid points that are not connectable in at least one discrete velocity direction. Non-fully connected points require more complex connectivity judgments in the connected domain search because they may be located at the boundary of the connected domain or in an internal disconnected area.

[0035] Please refer to Figure 5 , Figure 5A schematic diagram of fully connected points and non-fully connected points is provided in Example 1 of the method for partitioning a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model of this application. The diagram shows the role of fully connected points and non-fully connected points in partitioning a connected domain. Figure 5 In (a), connected domains 0 and 1 are composed of fully connected points, which meet the connectivity conditions in all discrete speed directions. Therefore, the connected domain can be quickly divided through breadth-first search to obtain preliminary connected domain results. Due to their high connectivity, fully connected points can ensure the consistency within the connected domain, thereby quickly determining the boundaries of the connected domain during the search process. Figure 5 (b) in the figure shows non-fully connected points, which do not meet the connectivity condition in at least one discrete velocity direction, so they are located at the boundary of the connected domain or in the internal non-connected area. The introduction of non-fully connected points increases the complexity of the connected domain division. It is necessary to further process the non-fully connected points through breadth-first search on the basis of the full connection point division to ensure the accuracy and completeness of the connected domain. In this way, 3D geometric models of different qualities can be efficiently processed, and the connected domain can be accurately divided to meet the needs of complex production scenarios.

[0036] Under the definition of connectivity 2, using the D3Q19 lattice configuration to evaluate the connectivity between two grid points requires checking the connection relationship in 34 directions, which will lead to inefficiency in practical applications. In order to solve this problem, the present application proposes a fully connected point connected domain pre-search technology to improve the search efficiency. A fully connected point refers to a grid point that meets the connectivity conditions in all discrete speed directions. According to the definition of connectivity, any two adjacent fully connected points must simultaneously meet the requirements of connectivity 0, 1, and 2. Before performing a search task of any connectivity, the present application will pre-identify and mark all fully connected points, and then perform a breadth-first search on these fully connected points, and perform a preliminary division of the connected domain with a connectivity of 0. Figure 5 It is shown that in actual production environments, most grid points are fully connected points, which means that they dominate the connected domain. Since the complexity of the connected domain search for fully connected points is proportional to the number of grid points, the higher the proportion of fully connected points in the grid, the less the efficiency of the connected domain search is affected by changes in connectivity. This technical feature ensures that this method can achieve efficient connected domain search in most production scenarios, thereby optimizing the entire connected domain partitioning process.

[0037] It can be understood that, first, the lattice configuration is selected according to the actual application scenario, and the discrete velocity directions are determined according to the lattice configuration. Secondly, all grid points are traversed to check the connectivity of each grid point in all discrete velocity directions. If a grid point meets the connectivity conditions in all relevant directions, it is marked as a fully connected point; otherwise, it is marked as a non-fully connected point. Finally, through this classification, it is possible to quickly distinguish which grid points are connected in all directions (fully connected points) and which grid points have disconnected directions (non-fully connected points), thereby providing a basis for subsequent connected domain searches, improving search efficiency, and ensuring the flexibility and robustness of connected domain division.

[0038] Step S20, numbering the connected domains of the fully connected points and the non-fully connected points by a breadth-first search method, saving the numbered grid points and the corresponding connected domain numbers to a grid connected domain numbering recording system, and saving the merging relationship between different connected domains to a connected domain numbering system.

[0039] It should be noted that BFS (Breadth-First Search) is an algorithm for graph traversal. It starts from a starting node and traverses all nodes in the graph layer by layer. In this embodiment, the breadth-first search method is used to search and divide connected domains. The connected domain number has two interpretations: verbal and nominal: (1) Verbal interpretation: It means that during the connected domain search process, a unique number is assigned to each connected domain. This number is used to distinguish different connected domains and record the connected domain to which each grid point belongs. (2) Noun interpretation: It refers to the unique identifier assigned to each connected domain. In the data structure, the connected domain number is used to record and manage the information of the connected domain.

[0040] Grid connected domain numbering system (also called data structure ) is a structure that stores grid point information and corresponding connected domain numbers, which can realize the function of quickly finding the corresponding connected domain number through grid point coordinates.

[0041] The merge relationship refers to the situation that during the connected domain search, two grid points that originally belonged to different connected domains are found to be connected, so the two connected domains need to be merged into one connected domain. Specifically, during the breadth-first search, if a grid point is found to be connected to another grid point that has been marked as a different connected domain, the merge relationship between the two connected domains needs to be recorded. The record of the merge relationship is used for subsequent connected domain number updates to ensure that all connected grid points eventually belong to the same connected domain.

[0042] Connected Domain Numbering System (also called Data Structure ) is a data structure used to manage and update the connected domain numbers. It records the merging relationship between connected domains and uniformly updates the connected domain numbers after the search is completed. During the connected domain search process, whenever two connected domains are found to need to be merged, the data structure This merge relationship will be recorded.

[0043] It can be understood that, first, the breadth-first search method is used to divide the connected domains of fully connected points and non-fully connected points. Starting from an unmarked grid point, add it to the queue as the starting point and assign it a temporary connected domain number. Then, take out the grid points from the queue one by one and check the connectivity of all its adjacent grid points. If the adjacent grid point meets the connectivity condition and is not marked, the adjacent grid point is marked as part of the current connected domain and added to the queue. At the same time, the coordinates and connected domain number of the grid point are recorded in the grid point connected domain number recording system. During the search process, if it is found that a grid point has been marked as part of another connected domain, the merge relationship between the two connected domains is recorded and the merge relationship is saved in the connected domain numbering system.

[0044] As an example, the steps of numbering the connected domains of the fully connected points by a breadth-first search method, saving the numbered grid points and the corresponding connected domain numbers to a grid connected domain number recording system, and saving the merge relationship between different connected domains to the connected domain numbering system include: initializing a fully connected search queue and a connected domain number counter, wherein the connected domain number counter records a first current connected domain number; selecting a point from the fully connected points that has not been recorded by the grid connected domain number recording system as a first starting point, and adding the first starting point to the fully connected search queue; recording the coordinates of the first starting point and the first current connected domain number in the grid connected domain number recording system; performing a breadth-first search on the fully connected search queue, and recording the grid points and the corresponding connected domain numbers to the grid connected domain number recording system during the search, and recording the merge relationship between connected domains to the connected domain numbering system; incrementing the first current connected domain number in the connected domain number counter; and returning to the step of selecting a point from the fully connected points that has not been recorded by the grid connected domain number recording system as the first starting point, until all points in the fully connected points are recorded by the grid connected domain number recording system.

[0045] The fully connected search queue is a data structure used for breadth-first search, which is used to store fully connected points to be processed. During the connected domain search process, each point in the queue will be taken out in turn and the connectivity of its adjacent points will be checked. If the adjacent point meets the connectivity conditions and is not marked, it will be added to the queue. This queue ensures that the search process is carried out in a hierarchical order, so that all connected grid points can be traversed efficiently.

[0046] The connected domain number counter is a counter used to record the current connected domain number. It is dynamically updated during the search process and assigns a unique number to each newly discovered connected domain to facilitate subsequent connected domain management and merging operations. In the fully connected point search phase, the connected domain number counter records the first current connected domain number, which is used to distinguish different fully connected point connected domains.

[0047] The first current connected domain number refers to the number currently assigned to the newly discovered connected domain in the fully connected point search phase. It is the value of the connected domain number counter in the fully connected point search phase. Each time a new connected domain is discovered, the connected domain number counter is incremented, thereby assigning a unique number to the new connected domain. This number is used to record the connected domain to which each grid point belongs in the grid connected domain number recording system. The first starting point refers to the first point selected from the fully connected points that has not been recorded by the grid connected domain number recording system in the fully connected point search phase. This point is used as the starting point of the breadth-first search to trigger the search for a new connected domain. The purpose of selecting the first starting point is to ensure that all unmarked fully connected points can be traversed, thereby completing the division of the connected domains of all fully connected points. Coordinates refer to the position information of the grid point in space. In three-dimensional space, the coordinates of each grid point are usually represented by three components (x, y, z). In the grid connected domain number recording system, the coordinates of each grid point are recorded so that the connected domain information of the grid point can be quickly queried and updated later. The coordinates are the unique identifier of the grid point, ensuring that each grid point can be accurately identified and operated in the system.

[0048] First, initialize an empty fully connected search queue (also called search queue ) and a connected domain number counter, and the initial value of the connected domain number counter is set to 1. This value is called the first current connected domain number, which is used to identify the connected domain of the fully connected point. This is done to assign a unique number to each newly discovered connected domain to ensure the distinction between connected domains and the convenience of subsequent management. Secondly, traverse the set of fully connected points and find a point that has not been recorded by the grid connected domain number recording system. Use it as the first starting point. The unrecorded point is selected to ensure that each connected domain can be fully searched to avoid omissions. Add the first starting point to the fully connected search queue, and record the coordinates of the point and the first current connected domain number in the grid connected domain number recording system. This step is to mark the connected domain to which the starting point belongs and provide basic information for subsequent searches.

[0049] Then, a breadth-first search is performed on the fully connected search queue. A point is taken out of the queue and the connectivity of all its adjacent points is checked. If the adjacent point is not recorded and meets the connectivity condition, the adjacent point is added to the queue and the coordinates and connected domain number of the point are recorded in the grid connected domain numbering recording system. This step is to gradually expand the current connected domain and ensure that all connected points are correctly marked. If it is found during the search process that the adjacent point already belongs to other connected domains, the merge relationship between the two connected domains is recorded in the connected domain numbering system. This step is to handle the intersection between connected domains and ensure that the final connected domain division is accurate.

[0050] Finally, when the fully connected search queue is empty, it means that the search of the current connected domain is completed. At this time, the first current connected domain number in the connected domain number counter is incremented to prepare for the search of the next connected domain. Then return to the step of selecting the first starting point, continue to find the next unrecorded fully connected point, and repeat the above search process until all fully connected points are recorded by the grid connected domain number recording system. This ensures that all fully connected points are correctly divided into different connected domains, and finally completes the connected domain division of all fully connected points.

[0051] Please refer to Figure 6 , Figure 6 The schematic diagram of the connected domain search process of the fully connected points provided in the embodiment 1 of the method for connecting domain partitioning supporting multiple connectivity based on the LBM discrete velocity model of this application describes in detail how to divide the connected domain of the fully connected points through the breadth-first search algorithm. The process starts with initializing the fully connected point set And traversal number d = 0 starts, all connection points Added to the breadth-first search queue In. Algorithm check queue If it is 0, the search ends; if it is not 0, the first grid point in the queue is taken out and remove it from the queue. Next, check Is it already in the data structure is marked in, if not, then Record and d, then check all Adjacent grid points For each adjacent point, if belong and is not marked, then Medium Mark and d, and Add to search queue If Already in In the data structure, different numbers d' are marked. Then, d and d' need to be added to the data structure later. to reflect that the connected domains represented by these two numbers are actually connected. This process continues until the search queue is empty, at this time all fully connected points are correctly divided into the corresponding connected domains, thus completing the efficient search of the connected domain.

[0052] As an example, the step of performing a breadth-first search on the fully connected search queue, and recording the grid points and the corresponding connected domain numbers into the grid connected domain number recording system during the search process, and recording the merge relationship between connected domains into the connected domain number system includes: popping out a point from the fully connected search queue and recording it as the first current point; traversing the first adjacent points of the first current point in all discrete speed directions; when the first adjacent point is a fully connected point and the first adjacent point has not been recorded by the grid connected domain number recording system, adding the first adjacent point to the fully connected search queue, and recording the coordinates of the first adjacent point and the first current connected domain number in the grid connected domain number recording system; when the first adjacent point is recorded by the grid connected domain number recording system and the connected domain number corresponding to the first adjacent point is another connected domain number, recording the first current connected domain number and the other connected domain number as the merge relationship between connected domains into the connected domain number system, and the other connected domain number refers to the connected domain number other than the first current connected domain number; returning to the step of popping out a point from the fully connected search queue and recording it as the first current point until the fully connected search queue is empty.

[0053] The first current point refers to the point currently being processed that is popped out from the fully connected search queue during the breadth-first search process. It is the starting point of the current search and is used to trigger the connectivity check of adjacent points. Each time a point is popped out of the queue, this point becomes the first current point. Its function is to serve as the center point of the search and is used to check the connectivity of all its adjacent points.

[0054] The first neighboring point refers to the neighboring points of the first current point in all discrete velocity directions during the breadth-first search process. These neighboring points are the direct neighbors of the current point and are used to determine whether they are connected to the current point. Specifically: in three-dimensional space, according to the discrete velocity model (such as D3Q19 or D3Q27), each grid point has multiple discrete velocity directions, and the neighboring points in each direction are the first neighboring points. The connectivity check of the first neighboring points is the core step of the connected domain division. By checking whether these points meet the connectivity conditions, it can be determined whether they belong to the same connected domain.

[0055] Other connected domain numbers refer to other connected domain numbers in the grid connected domain number recording system, except for the connected domain number currently being processed (the first current connected domain number). Specifically, when checking a first adjacent point, if the point has been recorded in the grid connected domain number recording system, and its corresponding connected domain number is different from the first current connected domain number, then the number is called the other connected domain number. This situation indicates that the current connected domain has an intersection or connection relationship with other connected domains, and this merging relationship needs to be recorded so that the connected domains can be updated uniformly later.

[0056] First, a point is popped out from the fully connected search queue and marked as the first current point. This point is the center point of the current search and is used to trigger the connectivity check of the adjacent points. Next, the first adjacent points of the first current point in all discrete speed directions are traversed. These adjacent points are the direct neighbors of the current point and are used to determine whether they are connected to the current point. For each first adjacent point, check whether it is a fully connected point and has not been recorded by the grid connected domain number recording system. If so, it means that the adjacent point has not been divided into any connected domain, so it is added to the fully connected search queue, and the coordinates of the point and the current connected domain number are recorded in the grid connected domain number recording system, so as to ensure that subsequent searches can continue to expand from this point. If the first adjacent point has been recorded in the grid connected domain number recording system, and its corresponding connected domain number is different from other connected domain numbers, it means that the adjacent point belongs to another connected domain. At this time, the current connected domain number and other connected domain numbers need to be recorded as a merge relationship in the connected domain numbering system so that the connected domain can be updated uniformly later. Finally, return to the step of popping a point from the fully connected search queue and continue processing the next point in the queue until the fully connected search queue is empty, which means that the search of the current connected domain has been completed and all connected points have been correctly marked and recorded.

[0057] As an example, the steps of numbering the connected domains of the non-fully connected points by a breadth-first search method, saving the numbered grid points and the corresponding connected domain numbers to a grid connected domain number recording system, and saving the merge relationship between different connected domains to the connected domain numbering system include: determining the connectivity according to the connectivity requirements; initializing the non-fully connected search queue, and using the connected domain number in the connected domain number counter after the full connection point search is completed as the second current connected domain number; selecting a point from the non-fully connected points that has not been recorded by the grid connected domain number recording system as the second starting point; traversing the second adjacent points of the second starting point in all discrete speed directions; when all the second adjacent points and the second starting point do not meet the connectivity condition of the connectivity, skipping the second starting point, and returning to the step of selecting a point from the non-fully connected points that has not been recorded by the grid connected domain number recording system. The steps of: taking a point recorded by the grid connected domain number recording system as a second starting point; adding the second starting point to the non-fully connected search queue when at least one of the second adjacent points and the second starting point meets the connectivity condition of the connectivity; recording the coordinates of the second starting point and the second current connected domain number in the grid connected domain number recording system; performing a breadth-first search on the non-fully connected search queue, and recording the grid points and the corresponding connected domain numbers to the search grid connected domain number recording system during the search, and recording the merge relationship between connected domains to the connected domain number system; incrementing the second current connected domain number in the connected domain number counter; returning to the step of selecting a point from the non-fully connected points that has not been recorded by the grid connected domain number recording system as the second starting point, until all points in the non-fully connected points are recorded by the grid connected domain number recording system.

[0058] Connectivity requirements refer to the flexibility and robustness requirements for the division of connected domains in a three-dimensional geometric model based on the actual application scenario and model quality. Specifically: (1) Flexibility: Geometric models of different qualities require different connectivity constraints. The higher the geometric quality, the weaker the corresponding connectivity constraints (the smaller the connectivity, the weaker the constraints); the lower the geometric quality, the stronger the connectivity constraints. For example, a high-precision watertight geometric model may require a lower connectivity (allowing connectivity through small cracks), while a low-quality "dirty" geometric model (such as three-dimensional scan data) requires a higher connectivity (avoiding the influence of cracks). (2) Robustness: The division of connected domains needs to be able to handle defects such as cracks and damage in the geometric model to ensure that the division results conform to the intuitive geometric connected area. (3) Application scenarios: For example, in automobile simulation, the division of the internal and external meshes of the vehicle needs to select an appropriate connectivity based on the quality of the geometric model and the simulation requirements to ensure the accuracy and efficiency of the calculation.

[0059] The non-fully connected search queue is a data structure used for breadth-first search, which is specifically used to process the connected domain division of non-fully connected points. Similar to fully connected points, non-fully connected points also need to use breadth-first search to determine their connected domains. The non-fully connected search queue is used to store the non-fully connected points to be processed, ensuring that the search process can be carried out in a hierarchical order, thereby efficiently traversing all connected non-fully connected points.

[0060] The second current connected domain number refers to the number currently assigned to the newly discovered connected domain in the non-fully connected point search phase. It is the value of the connected domain number counter in the non-fully connected point search phase. Each time a new connected domain is discovered, the connected domain number counter increments, thereby assigning a unique number to the new connected domain. This number is used to record the connected domain to which each grid point belongs in the grid connected domain number recording system, ensuring that each connected domain has a unique identifier.

[0061] The second starting point refers to the first point selected from the non-fully connected point set during the non-fully connected point search phase that has not been recorded by the grid connected domain numbering recording system. This point is used as the starting point of the breadth-first search to trigger the search for a new connected domain. The unrecorded point is selected to ensure that all unmarked non-fully connected points can be traversed, thereby completing the division of the connected domains of all non-fully connected points.

[0062] The second neighboring point refers to the neighboring points of the current point (the second starting point or the point in the queue) in all discrete velocity directions during the breadth-first search process. These neighboring points are the direct neighbors of the current point and are used to determine whether they are connected to the current point. Specifically: in three-dimensional space, according to the discrete velocity model (such as D3Q19 or D3Q27), each grid point has multiple discrete velocity directions, and the neighboring points in each direction are the second neighboring points. The connectivity check of the second neighboring points is the core step of the connected domain division. By checking whether these points meet the connectivity conditions, it can be determined whether they belong to the same connected domain.

[0063] Connectivity conditions refer to the criteria for determining whether two grid points are connected under a given connectivity. Specifically, according to the definition of connectivity, connectivity conditions include unidirectional connectivity and multidirectional connectivity. For example, under connectivity 1, two grid points are connected in all directions within 45° of a discrete velocity direction. The connectivity condition is determined based on the connectivity mark of the grid points in the discrete velocity direction, ensuring that only grid points that meet the connectivity requirements are considered connected.

[0064] First, initialize an empty non-fully connected search queue (also called search queue ), and the connected domain number in the connected domain number counter after the full connection point search is completed is used as the second current connected domain number. This step is to ensure that the connected domain number of the non-fully connected point starts after the number of the fully connected point to avoid number conflicts. Next, a point that has not been recorded by the grid connected domain number recording system is selected from the non-fully connected point set as the second starting point. This step is to find an unprocessed non-fully connected point as the starting point of the current connected domain search.

[0065] Then, the second adjacent points of the second starting point in all discrete speed directions are traversed to check whether these adjacent points meet the connectivity condition with the second starting point. If all second adjacent points do not meet the connectivity condition, the second starting point is skipped and the step of selecting a new second starting point is returned. This step is to avoid processing isolated points and ensure that only points connected to adjacent points enter the search queue. If at least one second adjacent point meets the connectivity condition with the second starting point, the second starting point is added to the non-fully connected search queue, and the coordinates of the point and the second current connected domain number are recorded in the grid connected domain number recording system. This step is to mark the connected domain to which the current point belongs and add it to the search queue to expand the search.

[0066] Next, a breadth-first search is performed on the non-fully connected search queue. A point is taken out of the queue and the connectivity of all its adjacent points is checked. If the adjacent point meets the connectivity condition and has not been recorded, it is added to the queue and the coordinates and connected domain number of the point are recorded in the grid connected domain number recording system. If the adjacent point has been recorded and belongs to other connected domains, the merge relationship between the two connected domains is recorded in the connected domain numbering system. This step is to gradually expand the current connected domain and ensure that all connected points are correctly marked. When the non-fully connected search queue is empty, it means that the search of the current connected domain is completed. At this time, the second current connected domain number in the connected domain number counter is incremented to prepare for the search of the next connected domain.

[0067] Finally, return to the step of selecting a new second starting point and continue processing the next unrecorded non-fully connected point until all non-fully connected points are recorded by the grid connected domain numbering recording system. This step ensures that all non-fully connected points are correctly divided into different connected domains, completing the connected domain division of all non-fully connected points.

[0068] Please refer to Figure 7 , Figure 7 The schematic diagram of the connected domain search process of non-fully connected points provided in the embodiment 1 of the method for connecting domain partitioning supporting multiple connectivity based on the LBM discrete velocity model of this application describes in detail how to partition the connected domain of non-fully connected points. The process starts with initializing the non-fully connected point set Start with traversal number d=0 and check whether d is greater than the number of non-fully connected points. If so, end the search; otherwise, select a non-fully connected point. , and determine whether the point is connectable in at least one grid direction. If so, add it to the breadth-first search queue Next, perform a breadth-first search to check the queue Is it empty? If not, take out the first grid point in the queue. and remove it from the queue. Then, check Is it already in the data structure is marked in, if not, then Record and d, and check all Adjacent grid points For each adjacent point, if Fully connected point set and is not marked, then Medium Mark and d, and Join the search queue .if Already in In the data structure, different numbers d* are marked. Then, d and d* need to be added to the data structure. to reflect that the connected domains represented by these two numbers are actually connected. This process continues until the search queue is empty, at this time all non-fully connected points are correctly divided into the corresponding connected domains, completing the efficient search of the connected domain.

[0069] As an example, the steps of performing a breadth-first search on the non-fully connected search queue, and recording the grid points and the corresponding connected domain numbers into the search grid point connected domain number recording system during the search process, and recording the merge relationship between connected domains into the connected domain number recording system include: popping out a point from the non-fully connected search queue and recording it as the second current point; traversing the third adjacent points of the second current point in all discrete speed directions; and when the third adjacent point in the currently traversed discrete speed direction and the second current point meet the connectivity condition of the connectivity and the third adjacent point has not been recorded by the grid point connected domain number recording system, in the The grid connected domain number recording system records the third adjacent point and the second current connected domain number, and adds the third adjacent point to the non-fully connected search queue; when the third adjacent point and the second current point in the currently traversed discrete speed direction meet the connectivity condition of the connectivity and the third adjacent point has been recorded by the grid connected domain number recording system, the connected domain number corresponding to the third adjacent point and the second current connected domain number are recorded as a merge relationship in the connected domain numbering system; and the step of popping a point from the non-fully connected search queue and recording it as the second current point is returned until the non-fully connected search queue is empty.

[0070] The second current point refers to the point currently being processed that is popped out from the non-fully connected search queue during the breadth-first search of non-fully connected points. It is the center point of the current search and is used to trigger the connectivity check of adjacent points. Each time a point is popped out of the queue, this point becomes the second current point. It serves as the starting point of the search and is used to check the connectivity of all its adjacent points.

[0071] The third adjacent points refer to the adjacent points of the second current point in all discrete speed directions during the breadth-first search process. These adjacent points are direct neighbors of the second current point and are used to determine whether they are connected to the second current point.

[0072] First, a point is popped out from the non-fully connected search queue and recorded as the second current point. This point is the center point of the current search and is used to trigger the connectivity check of the adjacent points. Secondly, the third adjacent points of the second current point in all discrete speed directions are traversed. These adjacent points are the direct neighbors of the second current point and are used to determine whether they are connected to the second current point.

[0073] Then, for each third adjacent point, check whether it meets the connectivity condition. If the third adjacent point has not been recorded by the grid connected domain number recording system, and meets the connectivity condition with the second current point, the coordinates of the third adjacent point and the second current connected domain number are recorded in the grid connected domain number recording system, and the third adjacent point is added to the non-fully connected search queue. This step is to expand the current connected domain and ensure that all connected points are correctly marked. If the third adjacent point has been recorded in the grid connected domain number recording system and meets the connectivity condition with the second current point, the connected domain number corresponding to the third adjacent point and the second current connected domain number are recorded in the connected domain numbering system as a merge relationship. This step is to handle the intersection between connected domains and ensure that the final connected domain division is accurate.

[0074] Finally, we return to the step of popping a point from the non-fully connected search queue and continue to process the next point in the queue until the non-fully connected search queue is empty. This step ensures that all connected points are traversed and marked, and finally completes the connected domain division of the non-fully connected points. In this way, the connected domain division of non-fully connected points can be efficiently performed, and the merging relationship between connected domains can be processed to ensure the accuracy and consistency of the connected domain division.

[0075] Taking automobile simulation as an example, dirty geometry problems are common. Overlapping faces, non-manifold sets, low 3D scanning accuracy, loss of precision in complex geometric details, and loss of information in file format conversion are all common. These problems bring many challenges to the construction and production of automobile models. Overlapping faces may be caused by inaccurate alignment of the model during splicing, or errors in Boolean operations, resulting in overlap between faces. Non-manifold sets are caused by some irregular geometric elements generated when the topological structure of the model changes, such as edges shared by multiple faces, making the geometric structure of the model complex. Low 3D scanning accuracy may be due to the accuracy limitations of the scanning equipment itself, or the influence of environmental factors during the scanning process, resulting in errors in the geometric data obtained by the scan. The loss of precision in complex geometric details is caused by the simplification of some details in the design and manufacturing process of the model in order to pursue efficiency or reduce costs, resulting in the loss of geometric information.

[0076] All of the above dirty geometry problems are likely to lead to failures in the division of connected point sets, which in turn affects the production and simulation calculations of automobile models. Only accurate and intuitive geometric connected point set division can ensure that the solver is correctly called for simulation calculations, otherwise problems such as geometric description distortion and calculation divergence are likely to occur. This application is a technical solution proposed to address these difficulties. By optimizing the division of connected point sets, the dirty geometry problem can be effectively solved, and the production quality and efficiency of automobile digital simulation can be improved.

[0077] Please refer to Figure 8 , Figure 8 The schematic diagram of the connection of cracks and grid points near the cracks on the car model provided in the first embodiment of the method for partitioning the connected domain supporting multiple connectivity based on the LBM discrete velocity model of this application specifically includes three parts: Figure 8 Figure (a) shows the cracks in the front part of the car model. Such cracks may be caused by inaccurate model splicing or Boolean operation errors. Figure 8 Figure (b) further magnifies the crack area and more clearly shows the impact of the crack on the details of the car model; Figure 8 Figure (c) shows the connectivity of the grid points near the crack, where the grid points near the crack are marked with blue squares, and the red arrows indicate the impact of the crack on the connected domain division. When the connectivity is 0, the grid points inside and outside the car have a chance to connect through the crack, resulting in unsuccessful division of the connected domain inside and outside the car, increasing the computational overhead. Without repairing the crack, by selecting a higher connectivity (such as connectivity 2), the impact of the gap can be effectively reduced when searching for the connected point set, so that the grid points inside and outside the car are divided into different connected domains. This schematic diagram shows that by adjusting the connectivity, the connected domain division of the dirty geometry model can be optimized, improving the production quality and efficiency of automotive digital simulation.

[0078] Please refer to Fig. 9 , Fig. 9 The schematic diagram of the comparison between the failure and success of the vehicle internal and external connected domain division is provided in the first embodiment of the method for connecting domain division supporting multiple connectivity based on the LBM discrete velocity model of this application, including Figure (a) and Figure (b). Fig. 9 In (a), because the mesh at the crack location is small enough, or the connectivity selected when dividing the connected domain is low (for example, connectivity 0), the grid points inside and outside the car have a chance to connect through the crack, resulting in unsuccessful division of the connected domain inside and outside the car. At this time, the mesh inside the car is also generated, increasing the computational overhead. Fig. 9 In (b), by selecting a higher connectivity (e.g., connectivity 2) without repairing the cracks, the impact of the gaps can be effectively reduced when searching for connected point sets, so that the grid points inside and outside the vehicle are successfully divided into different connected domains. Therefore, only the grid points outside the vehicle can be selected for numerical simulation of the flow field during calculation, thus eliminating the computational overhead of the grid points inside the vehicle. This comparison diagram emphasizes that by adjusting the connectivity, the connected domain division of the dirty geometric model can be optimized, thereby improving the production quality and efficiency of automotive digital simulation.

[0079] Step S30: merging the connected domain numbers in the connected domain numbering system to obtain a target connected domain number.

[0080] It should be noted that the target connected domain number is the result of the connected domain division process recorded in the connected domain numbering system, which reflects the final number of each connected domain. In the connected domain division process, there may be a merge relationship between multiple connected domains, so the connected domain numbers need to be unified and merged to ensure that the number of each connected domain is unique and continuous.

[0081] It can be understood that after completing the connected domain division and search, the connected domain numbers in the connected domain numbering system need to be merged to obtain the final target connected domain number. Specifically, first traverse the connected domain numbering system to identify the merge relationships of all records, which indicate which connected domains are connected and need to be merged. For each pair of connected domain numbers that need to be merged, select one as the target connected domain number, and reallocate all grid points of the other number to this target number. At the same time, update the connected domain numbers of all relevant grid points in the grid connected domain number record system to ensure that they point to the new target connected domain number. In this way, all merge relationships are processed step by step, and finally a continuous and unique set of connected domain numbers is obtained, which are the target connected domain numbers.

[0082] As an example, the connected domain numbering system includes an associative container and a serial container, the associative container is used to record each connected domain number and the corresponding serial number, and the serial container is used to record the connected domain number after merging; the step of merging the connected domain numbers in the connected domain numbering system to obtain the target connected domain number includes: obtaining the first connected domain number and the second connected domain number to be merged from the connected domain numbering system; when the first connected domain number and the second connected domain number are different, checking whether the first connected domain number and the second connected domain number are recorded in the associative container; when the first connected domain number and the second connected domain number are both recorded In the case where the first connected domain number and the second connected domain number are recorded in the associative container, the first sequence number and the second sequence number corresponding to the first connected domain number and the second connected domain number are obtained from the associative container; the data in the associative container and the sequential container are updated according to the first sequence number and the second sequence number; when the data update is completed, the connected domain number queues in the sequential container are merged according to the connected domain number in the associative container; when the merging is completed, the step of obtaining the first connected domain number and the second connected domain number to be merged from the connected domain numbering system is returned until all the connected domain numbers in the connected domain numbering system are traversed to obtain the target connected domain number.

[0083] Associative containers (also called data structures ) is a data structure used to record each connected domain number and its corresponding sequence number. It is usually a set of key-value pairs, where the key is the connected domain number and the value is the sequence number corresponding to the connected domain number. The main function of the associative container is to quickly find and update the connected domain number and its sequence number. For example, a hash table or dictionary can be used to implement an associative container. Sequential containers (also called data structures) ) is a data structure used to record the connected domain numbers after merging. It is usually a collection of queues, where each queue represents a connected domain number after merging. The main function of the serial container is to manage the connected domain numbers after merging, ensuring that each connected domain number has a unique queue to record its merge relationship. For example, a list or array can be used to implement a serial container. The serial number refers to the unique identifier corresponding to each connected domain number in the associative container. The serial number is used to quickly locate and manage the connected domain numbers in the serial container. The serial number is usually an integer, starting from 0 and increasing.

[0084] Connectivity Domain Numbering System There are two sub-data structures and (Each element is a queue) composed of: For an associative container, record each number involved in the merge (key in the associative container) and the number in the structure in pairs. The corresponding sequence number (value in the associative container); structure It is a sequential container with queues as units, recording the numbers of the connected domains after merging. The number of internal queues represents the number of connected domains after merging, and the elements in each queue are the temporary connected domain numbers recorded in the current connected domain. Assume that a grid point is used as the starting point for the connected domain search, carrying the temporary connected domain number , diffuse the connected domain serial number to other grid points connected to it, when another grid point carries the temporary connected domain serial number During the search process When connected domains merge, Record , Record and Which one do they belong to? After the search for connected domains of fully connected points and non-fully connected points is completed, the data structure that stores the information of all grid connected domains (grid connected domain numbering system) is sorted according to the records of the serial numbering system. ) to update the overall connected domain serial number. This connected domain serial number system effectively avoids the modification of the global grid data structure during the search process, and only maintains the merging relationship between serial numbers, effectively reducing the computational overhead.

[0085] In the process of connecting domain number merging, the first connecting domain number refers to the number that is first identified or extracted in a pair of connecting domain numbers that need to be merged. It is the number of the first connecting domain involved in the current merging operation. In each merging operation, the system will process the merging relationship between the two connecting domain numbers in turn, and the first connecting domain number is the first one in the pair of numbers, which is used to identify a specific connecting domain to participate in the merging operation. Corresponding to the first connecting domain number, the second connecting domain number refers to the number that is later identified or extracted in a pair of connecting domain numbers that need to be merged. It is the number of the second connecting domain involved in the current merging operation. In the merging operation, the system will check whether there is a merging relationship between the connecting domains represented by the "first connecting domain number" and the "second connecting domain number". If so, they will be merged into a larger connecting domain and the relevant number information will be updated.

[0086] The first sequence number refers to the sequence number corresponding to the first connected domain number in the associative container, which is used to quickly locate the first connected domain number in the sequential container. The second sequence number refers to the sequence number corresponding to the second connected domain number in the associative container, which is used to quickly locate the second connected domain number in the sequential container. The connected domain number queue refers to the queue corresponding to each sequence number in the sequential container. Each queue records the merged connected domain number. For example, if two connected domain numbers need to be merged, they will be recorded in the same queue, indicating that they belong to the same merged connected domain.

[0087] First, a pair of first connected domain numbers and second connected domain numbers to be merged are extracted from the connected domain numbering system, which is the starting point of the merge operation. Next, it is determined whether the two numbers are different, because only connected domains with different numbers need to be merged. If they are different, further check whether the two numbers exist in the associative container, because the associative container records all valid connected domain numbers and their corresponding sequence numbers. If both numbers exist, obtain their respective first sequence numbers and second sequence numbers from the associative container. Then, according to the two sequence numbers, update the data in the associative container and the sequence container. This step is to reflect the merge relationship of the two connected domains in the system. After the data update is completed, according to the connected domain number in the associative container, the connected domain number queue in the sequence container is merged, that is, the two connected domains are classified into a larger connected domain and its number queue is updated. After the merge is completed, the next number to be merged is obtained from the connected domain numbering system again, and the above process is repeated until all connected domain numbers are traversed. Finally, all connected domains that need to be merged are correctly processed, and continuous and unique connected domain numbers, i.e., the target connected domain numbers, are obtained. This process ensures the accuracy and consistency of the connected domain division and provides accurate connected domain information for subsequent engineering simulation and analysis.

[0088] As an example, the step of updating the data in the associative container and the serial container according to the first sequence number and the second sequence number includes: when the first sequence number and the second sequence number are different, traversing the elements in the queue with the second sequence number in the serial container, and updating the sequence number corresponding to the element in the associative container to the first sequence number; inserting all elements in the queue with the second sequence number into the queue with the first sequence number in the serial container; deleting the queue with the second sequence number from the serial container; and when the deletion is completed, traversing the associative container and descending all sequence numbers greater than the second sequence number to complete the data update in the associative container and the serial container.

[0089] In the connected domain numbering system, the elements in a queue refer to the connected domain numbers contained in the queue corresponding to a specific serial number in the sequential container. Specifically, a sequential container is a set of storage queues, each queue represents a set of connected domain numbers after merging, and the elements in each queue (i.e., connected domain numbers) represent the numbers of all grid points belonging to the same connected domain. For example, if the queue with serial number 2 in the sequential container contains the element [5, 7, 9], this means that the connected domain numbers 5, 7, and 9 belong to the same connected domain after merging, and the serial number of the connected domain is 2.

[0090] In the merge operation, when you need to merge one connected domain number into another connected domain number, all elements in one queue will be moved to the other queue. For example, if you need to merge all elements in queue number 2 into queue number 1, then the elements [5, 7, 9] will be inserted into queue number 1, thus merging the two connected domains.

[0091] Descending means that in a sequential container, all sequence numbers greater than a certain sequence number are decremented, in this embodiment, by 1, to ensure the continuity and uniqueness of the sequence numbers. Specifically: in a merge operation, when a queue (for example, a queue with sequence number 2) is deleted, all queue sequence numbers greater than that sequence number need to be decremented by 1 to fill the vacancy caused by the deletion of the queue.

[0092] First, when it is found that the first sequence number and the second sequence number are different, the merge operation is started. The specific method is to traverse the queue with the second sequence number in the sequential container, check each connected domain number in the queue one by one, and for these elements, find their corresponding records in the associative container and change their sequence numbers from the second sequence number to the first sequence number. This is done to update the ownership of these connected domain numbers in the associative container so that they all point to the same merged connected domain.

[0093] Secondly, all the connected domain numbers in the queue with the second sequence number are copied as a whole to the queue with the first sequence number. This step is to merge the two connected domains into a larger connected domain in the sequential container, by merging all related numbers into the same queue to ensure that they belong to the same connected domain after the merger. After the copy is completed, the queue with the second sequence number is deleted from the sequential container, because all its elements have been merged into the queue with the first sequence number. Deleting it is to avoid repeated processing of these merged numbers in subsequent operations.

[0094] Finally, after deleting the queue with the second sequence number, in order to maintain the continuity of the sequence number, the sequence number in the associative container needs to be adjusted. The specific operation is to traverse the associative container, find all sequence numbers greater than the second sequence number, and reduce them by 1 respectively. The purpose of this is to fill the vacancy left by deleting the queue with the second sequence number, ensure that the sequence of the sequence numbers will not jump, and thus maintain the integrity and consistency of the entire connected domain numbering system. Through this series of operations, the data update in the associative container and the sequential container is completed, providing accurate numbering information for the subsequent connected domain division.

[0095] As an example, when the data update is completed, the step of merging the connected domain number queues in the sequential container according to the connected domain number in the associative container includes: when the data update is completed, the first connected domain number is recorded in the associative container and the second connected domain number is not recorded in the associative container, recording the second connected domain number in the connected domain number queue where the first connected domain number is located; when the second connected domain number is recorded in the associative container and the first connected domain number is not recorded in the associative container, recording the first connected domain number in the connected domain number queue where the second connected domain number is located; when both the first connected domain number and the second connected domain number are not recorded in the associative container, using the number of connected domains in the sequential container as a new connected domain sequence number; recording the first connected domain number, the second connected domain number and the new connected domain sequence number in the associative container; and adding a new queue containing the first connected domain number and the second connected domain number to the sequential container.

[0096] The new connected domain sequence number refers to a brand new sequence number assigned to the newly merged connected domain in the connected domain numbering system. This sequence number is generated based on the number of connected domains in the current serial container to ensure that each connected domain has a unique identifier. The new queue refers to a new queue created in the serial container for the newly merged connected domain. This queue is used to store all the connected domain numbers of the new connected domain.

[0097] First, when the data update is completed and the first connected domain number is recorded in the associative container, but the second connected domain number is not recorded, the second connected domain number is recorded in the connected domain number queue where the first connected domain number is located. This step is to merge the second connected domain number into the connected domain where the first connected domain number is located. Second, when the second connected domain number is recorded in the associative container, but the first connected domain number is not recorded, the first connected domain number is recorded in the connected domain number queue where the second connected domain number is located. This step is to merge the first connected domain number into the connected domain where the second connected domain number is located.

[0098] Then, when the first connected domain number and the second connected domain number are not recorded in the associative container, it means that the connected domains represented by these two numbers are brand new and a new connected domain serial number needs to be assigned. This new serial number is an integer corresponding to the number of connected domains in the current serial container. Next, the first connected domain number, the second connected domain number and the new connected domain serial number are recorded in the associative container. This step is to establish a mapping relationship between the new connected domain number and the new serial number in the associative container.

[0099] Finally, a new queue containing the first connected domain number and the second connected domain number is added to the serial container. The sequence number of this new queue is the new connected domain sequence number, which is used to manage all the numbers of the newly merged connected domains. Through this series of operations, it is ensured that all connected domain numbers are correctly merged into the corresponding connected domains, and each connected domain has a unique sequence number and queue, thereby maintaining the integrity and consistency of the connected domain numbering system.

[0100] Please refer to Fig.10 , Fig.10 A schematic diagram of a flow chart of a connected domain number merging operation in a connected domain numbering system provided in Embodiment 1 of the method for connecting domains supporting multiple connectivity degrees based on the LBM discrete velocity model of the present application. The flow chart starts with checking the two numbers to be merged. and At the beginning, first check whether the two numbers are equal. If they are equal, the merge operation ends. If they are not equal, further check whether the two numbers are in the data structure There are records in If there is a record in Get the serial numbers corresponding to these two numbers , , and determine whether the two serial numbers are equal. If they are equal, the merge operation ends. If the serial numbers are not equal, initialize a counter c=0, and then check Does the queue with sequence number c contain If so, then Add to the queue with sequence number c and in the data structure Add records in { , c}, and increase the value of counter c. The queue with sequence number c does not contain , then directly increase the value of counter c and check whether c is greater than The number of queues, if yes, then end the merge operation, otherwise continue to perform the merge. If there is a record in , add another number to The corresponding queue in If two numbers are in If there is no record in either, add these two numbers as new queues to in and Add new records to the . During the merge process, if you need to update The serial number corresponding to a number in When inserting or deleting elements, corresponding operations will be performed to ensure the correctness and consistency of the numbering system. The entire process ensures that the merging operation of the connected domain number can be performed correctly to obtain the target connected domain number.

[0101] Show a simple example: by three times , , After the merge operation, two connected domains are finally obtained. Please refer to Fig.11 , Fig.11 The schematic diagram of the result of the three-times connected domain number merging operation provided in the first embodiment of the method for connecting domain partitioning supporting multiple connectivity based on the LBM discrete velocity model of this application is shown in FIG. hour, Recorded and ,and Recorded , the merge count c is 0. Then, in the merge hour, Recorded , , and , Recorded and , the merge count c is 1. Finally, in the merge hour, Recorded , , , and , Recorded and , the merge count c is 1. Through these three merge operations, the numbering system Multiple connected domains are successfully merged into a larger connected domain, ensuring the continuity and consistency of the connected domain numbering, and providing accurate connected domain information for subsequent engineering simulation and analysis.

[0102] Step S40, updating the grid connected domain number in the grid connected domain number recording system according to the target connected domain number, and completing the connected domain division.

[0103] It can be understood that, first, the grid point connected domain number recording system is traversed to find the connected domain number currently recorded for each grid point, and it is replaced with the corresponding latest number in the target connected domain number. This step is to ensure that the connected domain numbers of all grid points are consistent with the final connected domain division results. Secondly, after the update is completed, the entire connected domain division process is completed. At this time, each grid point in the grid point connected domain number recording system accurately belongs to its corresponding connected domain, and the connected domain division of all grid points is realized. The final connected domain division result can be used for subsequent engineering simulation and analysis, providing accurate geometric connectivity information for related applications.

[0104] This embodiment provides a method for connecting domain partitioning based on the LBM discrete velocity model and supporting multiple connectivity. First, a grid configuration is selected according to the actual application scenario, and the discrete velocity directions are determined according to the grid configuration, and all grid points are marked as fully connected points or non-fully connected points according to the discrete velocity direction. This step ensures the flexibility and robustness of the connected domain partitioning, can adapt to geometric models of different qualities, and avoids the influence of geometric cracks and damage on the partitioning results. Then, the connected domains of the fully connected points and non-fully connected points are numbered by the breadth-first search method, and the numbered grid points and the corresponding connected domain numbers are saved to the grid connected domain number recording system, and the merge relationship between different connected domains is saved to the connected domain numbering system. This process utilizes the efficiency of breadth-first search, can quickly traverse all connected grid points, and at the same time, by recording the merge relationship, ensures the accuracy of the connected domain partitioning. Then, the connected domain numbers in the connected domain numbering system are merged to obtain the target connected domain number. This step ensures the continuity and uniqueness of all connected domain numbers through the merging operation, avoids number jumps and redundancy, and thus ensures the integrity of the connected domain partitioning. Finally, the grid point connected domain number in the grid point connected domain number recording system is updated according to the target connected domain number to complete the connected domain division. This step ensures that the connected domain numbers of all grid points are consistent with the final connected domain division results, provides accurate connected domain information for subsequent engineering simulation and analysis, and ensures the accuracy and completeness of the connected domain division. Through this series of steps, this embodiment can efficiently and robustly divide connected domains in three-dimensional geometric models of different qualities to meet the needs of complex engineering scenarios.

[0105] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can refer to the above introduction, and will not be repeated later. Fig.12 , Fig.12 This is a flow chart of a second embodiment of a method for partitioning a connected domain supporting multiple connectivity based on an LBM discrete velocity model of the present application. Step S40 of the method for partitioning a connected domain supporting multiple connectivity based on an LBM discrete velocity model includes steps S41 to S43: Step S41, traversing the non-fully connected points, merging the target connected domain numbers according to the three-dimensional connection relationship between the non-fully connected points and adjacent connected domains, and obtaining a first reference connected domain number.

[0106] It should be noted that adjacent connected domains refer to connected domains that are directly adjacent to a non-fully connected point in three-dimensional space. Specifically: in a three-dimensional grid structure, each grid point (non-fully connected point) may be adjacent to multiple connected domains. These adjacent connected domains are determined by checking the adjacent points of the non-fully connected point in all discrete velocity directions. If the adjacent points belong to a connected domain, the connected domain is considered to be adjacent to the non-fully connected point. The identification of adjacent connected domains is based on the discrete velocity directions and connectivity conditions of the grid points, ensuring that all possible connection relationships are considered in three-dimensional space.

[0107] The three-dimensional connection relationship refers to whether there is an actual, geometrically intuitive connection relationship between a non-fully connected point and its surrounding adjacent connected domains in three-dimensional space. This connection relationship not only considers the direct connectivity between points, but also the indirect connectivity that may exist in three-dimensional space. If a non-fully connected point is directly connected to the grid points of a connected domain in a discrete velocity direction, it is considered that the non-fully connected point has direct connectivity with the connected domain. Even if a non-fully connected point is not directly connected in a certain direction, if it can reach a connected domain through other paths (such as through multiple adjacent points), it is considered that there is indirect connectivity. For example, at a connectivity of 1, if a non-fully connected point is connected to the grid points of a connected domain in a certain direction and all directions within a 45° range, it is considered that there is a three-dimensional connection. The judgment of three-dimensional connection also needs to conform to geometric intuition, that is, whether two connected domains are geometrically connected in three-dimensional space. For example, if two connected domains are geometrically connected through a small channel or crack, it is considered that there is a three-dimensional connection.

[0108] The first reference connected domain number refers to the reference number obtained by merging the target connected domain number according to the three-dimensional connection relationship when processing non-fully connected points, and is used for subsequent connected domain division and processing. The purpose of the first reference connected domain number is to ensure that when processing non-fully connected points, the connected domain division result can reflect the actual connection relationship in the three-dimensional space, avoiding inaccurate connected domain division due to the existence of non-fully connected points.

[0109] Please refer to Fig.13 , Fig.13 The following is a schematic diagram comparing the actual search results of the connected domain when the connectivity is 2 and the expected search results provided in Example 2 of the method for partitioning connected domains supporting multiple connectivity based on the LBM discrete velocity model of this application. In the figure, the red dots represent the geometric internal connected domains, which form a complete and continuous geometric structure in three-dimensional space. The dots of different colors in the figure represent scattered connected domains on the geometric edges. These points are located at the edge of the geometric structure and are relatively small in number, showing a scattered distribution. When the connectivity is 1 or 2, based on the characteristics of the connectivity judgment rule, there will be a large number of scattered connected domains on the geometric edges ( Fig.13 (a) in the figure), which does not conform to the intuitive expectation of geometric connectivity. Fig.13 In (b) of Figure 1, the connected domain merging method based on mesh volume connection is used to smoothly merge the scattered connected domains on the geometric edge into the connected domains inside the geometry, which conforms to the actual situation of the geometric structure.

[0110] It can be understood that, first, each non-fully connected point is checked in turn. Due to its particularity (at least in one direction, it cannot be connected), special processing is required to ensure the accuracy of the connected domain division. For each non-fully connected point, the connection between it and the surrounding determined connected domains is analyzed. This connection is not limited to direct proximity, but may also involve complex three-dimensional structures indirectly connected through other grid points, that is, three-dimensional connection relationships. If it is found that a non-fully connected point has such a three-dimensional connection relationship with multiple different connected domains, it means that these connected domains are actually connected in three-dimensional space, although they may be separated during the initial division. Therefore, it is necessary to merge the target connected domain numbers of these connected domains, that is, to unify them into a new number. After the connected domain numbers corresponding to all connected domains with three-dimensional connection relationships in the target connected domain numbers are merged accordingly, all the numbers obtained are the first reference connected domain numbers. In this way, the connected domain division errors caused by non-fully connected points can be corrected, ensuring that the connected domain division is more in line with the actual three-dimensional geometric structure, and providing more accurate connected domain information for subsequent engineering simulation and analysis.

[0111] As an example, the step of traversing the non-fully connected points, merging the target connected domain numbers according to the three-dimensional connection relationship between the non-fully connected points and the adjacent connected domains, and obtaining the first reference connected domain number includes: traversing the non-fully connected points, recording the connection relationship between each non-fully connected point and the surrounding adjacent connected domains; when the connection relationship is a three-dimensional connection relationship, recording the first connected domain of the non-fully connected points corresponding to the connection relationship and the second connected domain corresponding to the connection relationship; traversing all connection directions of the non-fully connected points, recording the connected grid point set belonging to the first connected domain or the second connected domain in the connection direction; when the connected grid point set merges the non-fully connected points to satisfy the grid body connection, merging the connected domain numbers corresponding to the first connected domain and the second connected domain in the target connected domain number to obtain the first reference connected domain number.

[0112] The connection relationship refers to the connectivity between a non-fully connected point and its surrounding adjacent connected domains. It describes whether the non-fully connected point is connected to the grid points of a connected domain in a certain direction.

[0113] The first connected domain refers to the connected domain to which the non-fully connected point belongs. When traversing the non-fully connected points, each non-fully connected point itself belongs to a connected domain, and this connected domain is the first connected domain. The first connected domain is determined by the previous connected domain division step. It records the connected domain number to which the non-fully connected point currently belongs. The first connected domain is the starting point of the merge operation and is used to determine which other connected domains the non-fully connected point has a connection relationship with.

[0114] The second connected domain refers to a connected domain that has a three-dimensional connection relationship with a non-fully connected point. When checking the connection relationship between a non-fully connected point and its surrounding adjacent connected domains, if a certain adjacent connected domain is found to be connected to the non-fully connected point through a three-dimensional connection relationship, then the connected domain is called the second connected domain. The second connected domain is the target of the merge operation and is used to determine the connected domain that needs to be merged with the first connected domain.

[0115] The connected grid point set refers to the set of all connected grid points belonging to the first connected domain or the second connected domain in a certain connection direction. It includes all grid points connected to the first connected domain or the second connected domain through non-fully connected points. These grid points form a path in three-dimensional space, indicating the connection relationship between the two connected domains.

[0116] Mesh connection refers to whether two connected domains connected by non-fully connected points in three-dimensional space can form a complete mesh. If the connected grid point set can form a complete mesh structure (the formed mesh is geometrically closed, that is, there are no breakpoints or cracks) after fusing the non-fully connected points (that is, treating these points as points in a set, as a whole), and can be geometrically merged into a connected whole (continuous geometric structure), then it is considered that there is a mesh connection between the two connected domains. This step is to ensure that the merger of two connected domains in three-dimensional space is reasonable and conforms to geometric intuition.

[0117] First, check each non-fully connected point one by one to determine its connection relationship with the surrounding connected domains. If it is found that a non-fully connected point has a three-dimensional connection relationship with two connected domains, that is, the two connected domains are connected in three-dimensional space through the non-fully connected point, then record the first connected domain to which the non-fully connected point belongs and the second connected domain connected to it. Next, check all the connection directions of the non-fully connected point in detail, and collect the connected grid point sets belonging to the first connected domain or the second connected domain. These connected grid point sets depict the connection path between the two connected domains. If these connected grid point sets can form a complete grid structure after being combined with the non-fully connected points, that is, the two connected domains form a continuous and closed geometric structure in three-dimensional space through these grid points and non-fully connected points, then it is necessary to merge the numbers of the first connected domain and the second connected domain in the target connected domain number. After merging all the numbers that meet the above conditions in the target connected domain number, a new number set is obtained, namely the first reference connected domain number. This process ensures the accuracy and completeness of the connected domain division in three-dimensional space, avoids the connected domain division errors caused by the existence of non-fully connected points, and provides more accurate connected domain information for subsequent engineering simulation and analysis.

[0118] Taking automobile geometry as an example, when the connectivity is 2, after completing the search for the connected domains of fully connected points and non-fully connected points, the connected points at the middle section position are divided as follows Fig.14 As shown, Fig.14 A schematic diagram of the search results of the geometric connected domains of a car provided in Example 2 of the method for partitioning connected domains supporting multiple connectivity degrees based on the LBM discrete velocity model of the present application, wherein the red dots represent the connected domains inside the car, and the black dots represent the connected domains outside the car. Fig.14 (a) in the figure shows the connected domain division of the front part of the vehicle. The red points are concentrated in the front area, while the black points are distributed in the area outside the vehicle. Fig.14 As shown in (b), (c), and (d), before the body connection and merging operation ( Fig.14In (c) above, we can see that the connected domain point set is incomplete at the edge of the car geometry. After the volume connection merging operation ( Fig.14 In (d) in the figure, the grid points of the connected domains inside and outside the car can be basically seamlessly connected, and the two connected domains inside and outside the car are still correctly divided according to the geometric shape. This schematic diagram shows that by executing the volume connection merging operation, the problem of incomplete connected domain point sets at the geometric edge position can be effectively solved, thereby improving the production quality and efficiency of automotive digital simulation.

[0119] Step S42, deleting the to-be-deleted number in the first reference connected domain number to obtain a second reference connected domain number, wherein the to-be-deleted number is a connected domain number corresponding to a connected domain having a grid point number less than a preset grid point number threshold.

[0120] It should be noted that the numbers to be deleted refer to the numbers of connected domains in the first reference connected domain number whose corresponding number of connected domain grid points is less than the preset grid point number threshold. Specifically: in the process of connected domain division, each connected domain has a unique number, which is recorded in the target connected domain number in the connected domain number system; after the merging operation, the first reference connected domain number obtained may contain some connected domains, which have very few grid points and may have no practical significance in practical applications, and may even cause calculation instability; the numbers to be deleted are the numbers of connected domains whose number of grid points is less than the preset threshold, and need to be deleted from the first reference connected domain number.

[0121] The second reference connected domain number refers to a new connected domain number set obtained after deleting all the numbers to be deleted. The number of grid points refers to the total number of grid points contained in each connected domain. The number of grid points is an important indicator for measuring the size of the connected domain, which reflects the complexity of the connected domain and its importance in practical applications. The preset grid point number threshold is a threshold used to determine whether the connected domain has practical significance. In this embodiment, the preset grid point number threshold is set to 5. This means that if the number of grid points in a connected domain is less than 5, it is considered that the connected domain has no practical significance in practical applications and may be a "scattered" connected domain. The setting of this threshold is based on the needs and experience of practical applications, with the aim of ensuring that the final connected domain division result has practical significance and has computational stability in subsequent engineering simulation and analysis.

[0122] It can be understood that, first, each connected domain in the first reference connected domain number is evaluated, and the number of grid points contained in each connected domain is counted. Then, according to the preset grid point number threshold (for example, 5), the connected domains whose number of grid points is less than the threshold are screened out, and the numbers corresponding to these connected domains are the numbers to be deleted. Next, these numbers to be deleted are removed from the first reference connected domain number, thereby obtaining a new set of connected domain numbers, namely the second reference connected domain number. This process aims to remove those "scattered" connected domains that may have no practical significance or cause computational instability in practical applications, to ensure that the final connected domain division results have practical significance and computational stability, and to provide more accurate connected domain information for subsequent engineering simulation and analysis.

[0123] Step S43: updating the target connected domain number according to the second reference connected domain number.

[0124] It can be understood that after the first reference connected domain number is screened and the second reference connected domain number is obtained, the target connected domain number needs to be updated according to the second reference connected domain number. Specifically, all connected domain numbers in the target connected domain number are traversed, and for each number, it is checked whether it exists in the second reference connected domain number. If it exists, the number is retained; if it does not exist, it is deleted from the target connected domain number. This process ensures that the target connected domain number only contains connected domain numbers that have been screened and have practical significance, thereby improving the accuracy and practicality of the connected domain division results.

[0125] As an example, after step S43, it also includes: marking the grid points in the connected domain corresponding to the second reference connected domain number as valid connected domain grid points; traversing the adjacent grid points in all connected directions of the valid connected domain grid points; when the adjacent grid point is the valid connected domain grid point and the connected domain number of the valid connected domain grid point is different from the connected domain number of the adjacent grid point, recording the connected domain boundary according to the valid connected domain grid point, the connected domain number of the valid connected domain grid point, the connected direction between the valid connected domain grid point and the adjacent grid point, and the connected domain number of the adjacent grid point; when the adjacent grid point is not the valid connected domain grid point, recording the degenerate point connected domain boundary according to the valid connected domain grid point, the connected domain number of the valid connected domain grid point, and the connected direction between the valid connected domain grid point and the adjacent grid point.

[0126] The valid connected domain grid points refer to all grid points in the connected domain corresponding to the second reference connected domain number. These grid points are screened to ensure that the connected domain to which they belong has enough grid points and meets the preset grid point number threshold, so they are considered valid. The connection direction refers to the connection direction between grid points in three-dimensional space.

[0127] The connected domain boundary refers to the dividing line between two different connected domains in three-dimensional space. Specifically, when the adjacent grid points of a valid connected domain grid point belong to another connected domain, the connection direction between the two grid points defines the connected domain boundary; the connected domain boundary records the connection relationship between two different connected domains, which is very important for subsequent engineering simulation and analysis because it can help determine the interaction between different connected domains. For example, record the grid points of the valid connected domain. The connected domain number is , in the connected direction The sequence number of the valid connected domain is Grid ,if Not equal to , then record the connected domain boundary {“Starting connected domain sequence number”: , "Starting grid": , “Connectivity Direction”: , "End point connection domain number": }.

[0128] The degenerate point connected domain boundary refers to the boundary formed in three-dimensional space when the adjacent grid points of the valid connected domain grid point do not belong to any connected domain. Specifically: when the adjacent grid points of a valid connected domain grid point are not valid connected domain grid points, this adjacent grid point is considered to be a degenerate point; the degenerate point connected domain boundary records the connection relationship between the valid connected domain grid points and the degenerate points, which is very important for subsequent analysis and processing because it can help identify the boundaries of the connected domain and possible defects. If If it is an invalid connected domain point, the degenerate point connected domain boundary is recorded: {“Starting connected domain sequence number”: , "Starting grid": , “Connectivity Direction”: }.

[0129] First, all grid points in the connected domain corresponding to the second reference connected domain number are marked as valid connected domain grid points. This step is to clarify which grid points are of practical significance after screening. Then, the adjacent grid points in all connected directions of these valid connected domain grid points are traversed to check their connectivity. If the adjacent grid point is also a valid connected domain grid point, but the connected domain number it belongs to is different from the current grid point, this means that two different connected domains are connected here, so it is necessary to record the connected domain boundary, including the grid points involved, the connected domain number, the connected direction and other information. If the adjacent grid point is not a valid connected domain grid point, that is, it may belong to an invalid connected domain or is not divided into any connected domain, then the degenerate point connected domain boundary is recorded, also including the relevant grid points, connected domain number and connected direction and other information. This process helps to accurately identify and record the boundaries between connected domains, as well as the boundaries between connected domains and non-connected areas, providing detailed geometric information for subsequent engineering simulation and analysis.

[0130] The time complexity of the connected domain search method of this embodiment is mainly determined by the grid point connected domain search process. The total number of grid points is , the complexity of the full connection point search is , the complexity of non-fully connected point search is ,in is the number of connected directions that need to be traversed under different connectivity. The search time is greatly affected by the number distribution of fully connected points and non-fully connected points. If the number of fully connected points is , then the total connected domain search complexity is The time complexity of searching the connected domain boundary is .

[0131] This embodiment first traverses all non-fully connected points, checks the three-dimensional connection relationship between these points and the surrounding adjacent connected domains, and when it is found that two different connected domains are connected through non-fully connected points, merges the target connected domain numbers of the two connected domains to obtain a first reference connected domain number. This step ensures the accuracy and integrity of the connected domain division in three-dimensional space, avoids the connected domain division errors caused by non-fully connected points, and improves the robustness of the connected domain division. Then, the connected domain numbers whose grid number is less than the preset threshold are deleted from the first reference connected domain number to obtain the second reference connected domain number. This step removes the "scattered" connected domains that may be meaningless in practical applications, improves the calculation efficiency, and ensures the reliability of the connected domain division results. Finally, the target connected domain number is updated according to the second reference connected domain number to ensure that the target connected domain number only contains the connected domain numbers that have been screened and have practical significance, thereby improving the consistency and accuracy of the connected domain division results and providing a reliable basis for subsequent engineering simulation and analysis. Through this series of steps, this embodiment can efficiently, accurately and robustly complete the connected domain division to meet the needs of complex engineering scenarios.

[0132] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the method of partitioning connected domains supporting multiple connectivity based on the LBM discrete velocity model of the present application. More forms of simple transformations based on this technical concept are all within the scope of protection of the present application.

[0133] The present application also provides a connected domain partitioning device supporting multiple connectivity degrees based on the LBM discrete velocity model. Please refer to Fig.15 The device for partitioning a connected domain supporting multiple connectivity degrees based on the LBM discrete velocity model comprises: A grid point marking module 10, used to mark all grid points as fully connected points or non-fully connected points; A connected domain numbering module 20 is used to perform connected domain numbering on the fully connected points and the non-fully connected points by a breadth-first search method, save the numbered grid points and the corresponding connected domain numbers to a grid point connected domain numbering recording system, and save the merging relationship between different connected domains to a connected domain numbering system; A connected domain merging module 30, configured to merge connected domain numbers in the connected domain numbering system to obtain a target connected domain number; The numbering updating module 40 is used to update the grid point connected domain number in the grid point connected domain number recording system according to the target connected domain number, so as to complete the connected domain division.

[0134] The device for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity provided by the present application adopts the method for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity in the above-mentioned embodiment, and can solve the technical problem of how to efficiently and robustly divide the connected domain in three-dimensional geometric models of different qualities to meet the needs of engineering simulation. Compared with the prior art, the beneficial effects of the device for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity provided by the present application are the same as the beneficial effects of the method for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity provided by the above-mentioned embodiment, and the other technical features of the device for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity are the same as the features disclosed in the above-mentioned embodiment method, which will not be repeated here.

[0135] The present application provides a device for partitioning a connected domain that supports multiple connectivity based on an LBM discrete velocity model. The device for partitioning a connected domain that supports multiple connectivity based on an LBM discrete velocity model includes: at least one processor; and a memory that is communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method for partitioning a connected domain that supports multiple connectivity based on the LBM discrete velocity model in the above-mentioned embodiment 1.

[0136] Reference below Fig.16 , which shows a schematic diagram of the structure of a connectivity domain partitioning device supporting multiple connectivity based on the LBM discrete velocity model suitable for implementing the embodiment of the present application. The connectivity domain partitioning device supporting multiple connectivity based on the LBM discrete velocity model in the embodiment of the present application may include but is not limited to mobile terminals such as mobile phones, laptops, digital broadcast receivers, PDAs (Personal Digital Assistants), PADs (Portable Application Descriptions), PMPs (Portable Media Players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), etc., and fixed terminals such as digital TVs, desktop computers, etc. Fig.16 The connected domain partitioning device supporting multiple connectivity degrees based on the LBM discrete velocity model shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0137] like Fig.16As shown, the device for partitioning a connected domain supporting multiple connectivity based on the LBM discrete velocity model may include a processing device 1001 (e.g., a central processing unit, a graphics processor, etc.), which can perform various appropriate actions and processes according to a program stored in a ROM (Read Only Memory) 1002 or a program loaded from a storage device 1003 to a RAM (Random Access Memory) 1004. Various programs and data required for the operation of the device for partitioning a connected domain supporting multiple connectivity based on the LBM discrete velocity model are also stored in the RAM 1004. The processing device 1001, the ROM 1002, and the RAM 1004 are connected to each other via a bus 1005. An input / output (I / O) interface 1006 is also connected to the bus. Typically, the following systems may be connected to the I / O interface 1006: an input device 1007 including, for example, a touch screen, a touchpad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; an output device 1008 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; a storage device 1003 including, for example, a magnetic tape, a hard disk, etc.; and a communication device 1009. The communication device 1009 may allow the multi-connectivity-supporting connected domain partitioning device based on the LBM discrete velocity model to communicate wirelessly or wired with other devices to exchange data. Although the figure shows a multi-connectivity-supporting connected domain partitioning device based on the LBM discrete velocity model with various systems, it should be understood that it is not required to implement or have all the systems shown. More or fewer systems may be implemented or have alternatively.

[0138] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program includes a program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device 1003, or installed from a ROM 1002. When the computer program is executed by the processing device 1001, the above-mentioned functions defined in the method of the embodiment disclosed in the present application are executed.

[0139] The device for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity provided by the present application adopts the method for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity in the above-mentioned embodiment, which can solve the technical problem of how to efficiently and robustly divide the connected domain in three-dimensional geometric models of different qualities to meet the needs of engineering simulation. Compared with the prior art, the beneficial effects of the device for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity provided by the present application are the same as the beneficial effects of the method for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity provided by the above-mentioned embodiment, and the other technical features of the device for dividing a connected domain based on the LBM discrete velocity model and supporting multiple connectivity are the same as the features disclosed in the method of the previous embodiment, which will not be repeated here.

[0140] It should be understood that the various parts disclosed in this application can be implemented by hardware, software, firmware or a combination thereof. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0141] 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 who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0142] The present application provides a computer-readable storage medium having computer-readable program instructions (i.e., computer programs) stored thereon, and the computer-readable program instructions are used to execute the method for partitioning a connected domain supporting multiple connectivity degrees based on an LBM discrete velocity model in the above-mentioned embodiment.

[0143] The computer-readable storage medium provided in the present application may be, for example, a USB flash drive, but is not limited to electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, systems or devices, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM: Random Access Memory), a read-only memory (ROM: Read Only Memory), an erasable programmable read-only memory (EPROM: Erasable Programmable Read Only Memory or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM: CD-Read Only Memory), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this embodiment, the computer-readable storage medium may be any tangible medium containing or storing a program, which may be used by or in combination with an instruction execution system, system or device. The program code contained on the computer-readable storage medium may be transmitted using any appropriate medium, including but not limited to: wires, optical cables, RF (Radio Frequency: Radio Frequency), etc., or any suitable combination of the above.

[0144] The above-mentioned computer-readable storage medium can be included in the connected domain partitioning device supporting multiple connectivity based on the LBM discrete velocity model; or it can exist independently without being assembled into the connected domain partitioning device supporting multiple connectivity based on the LBM discrete velocity model.

[0145] The computer-readable storage medium carries one or more programs. When the one or more programs are executed by a connected domain partitioning device supporting multiple connectivity based on an LBM discrete velocity model, the connected domain partitioning device supporting multiple connectivity based on an LBM discrete velocity model: marks all grid points as fully connected points or non-fully connected points; performs connected domain numbering on the fully connected points and the non-fully connected points through a breadth-first search method, saves the numbered grid points and the corresponding connected domain numbers to a grid connected domain numbering recording system, and saves the merging relationship between different connected domains to a connected domain numbering system; merges the connected domain numbers in the connected domain numbering system to obtain a target connected domain number; updates the connected domain numbers of the grid points in the grid connected domain numbering recording system according to the target connected domain number, and completes the connected domain partitioning.

[0146] Computer program code for performing the operations of the present application may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0147] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two square boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or flow chart, and the combination of the square boxes in the block diagram and / or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0148] The modules involved in the embodiments described in this application may be implemented by software or hardware, wherein the name of the module does not constitute a limitation on the unit itself in some cases.

[0149] The readable storage medium provided by the present application is a computer-readable storage medium, which stores computer-readable program instructions (i.e., computer programs) for executing the above-mentioned method for partitioning a connected domain supporting multiple connectivity based on the LBM discrete velocity model, and can solve the technical problem of how to efficiently and robustly partition connected domains in three-dimensional geometric models of different qualities to meet the needs of engineering simulation. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by the present application are the same as the beneficial effects of the method for partitioning a connected domain supporting multiple connectivity based on the LBM discrete velocity model provided by the above-mentioned embodiment, and will not be repeated here.

[0150] The present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the steps of the above-mentioned method for partitioning a connected domain supporting multiple connectivity degrees based on an LBM discrete velocity model.

[0151] The computer program product provided by the present application can solve the technical problem of how to efficiently and robustly divide connected domains in three-dimensional geometric models of different qualities to meet the needs of engineering simulation. Compared with the prior art, the beneficial effects of the computer program product provided by the present application are the same as the beneficial effects of the connected domain division method supporting multiple connectivity based on the LBM discrete velocity model provided in the above embodiment, which will not be repeated here.

[0152] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A method for partitioning a connected domain supporting multiple connectivity degrees based on an LBM discrete velocity model, characterized in that: The method comprises: Mark all grid points as fully connected points or non-fully connected points; The connected domains of the fully connected points and the non-fully connected points are numbered by a breadth-first search method, the numbered grid points and the corresponding connected domain numbers are saved in a grid point connected domain numbering recording system, and the merging relationship between different connected domains is saved in a connected domain numbering system; Merging the connected domain numbers in the connected domain numbering system to obtain a target connected domain number; The grid point connected domain number in the grid point connected domain number recording system is updated according to the target connected domain number to complete the connected domain division.

2. The method according to claim 1, characterized in that The steps of numbering the connected domains of the fully connected points by a breadth-first search method, saving the numbered grid points and the corresponding connected domain numbers to a grid point connected domain numbering recording system, and saving the merging relationship between different connected domains to the connected domain numbering system include: Initialize a fully connected search queue and a connected domain number counter, wherein the connected domain number counter records a first current connected domain number; Selecting a point from the fully connected points that has not been recorded by the grid connected domain number recording system as a first starting point, and adding the first starting point to the fully connected search queue; Recording the coordinates of the first starting point and the first current connected domain number in the grid connected domain number recording system; Performing a breadth-first search on the fully connected search queue, and during the search process, recording the grid points and the corresponding connected domain numbers into the grid point connected domain number recording system, and recording the merging relationship between connected domains into the connected domain numbering system; Incrementing the first current connected domain number in the connected domain number counter; Return to the step of selecting a point from the fully connected points that has not been recorded by the grid connected domain number recording system as the first starting point, until all points in the fully connected points are recorded by the grid connected domain number recording system.

3. The method according to claim 2, characterized in that The steps of performing a breadth-first search on the fully connected search queue, recording the grid points and the corresponding connected domain numbers into the grid point connected domain number recording system during the search process, and recording the merging relationship between connected domains into the connected domain numbering system include: Popping a point from the fully connected search queue and recording it as the first current point; Traversing the first adjacent points of the first current point in all discrete velocity directions; When the first neighboring point is a fully connected point and the first neighboring point has not been recorded by the grid point connected domain number recording system, adding the first neighboring point to the fully connected search queue, and recording the coordinates of the first neighboring point and the first current connected domain number in the grid point connected domain number recording system; When the first adjacent point is recorded by the grid connected domain number recording system and the connected domain number corresponding to the first adjacent point is another connected domain number, the first current connected domain number and the other connected domain number are recorded in the connected domain numbering system as a merge relationship between connected domains, and the other connected domain number refers to a connected domain number other than the first current connected domain number; Return to the step of popping a point from the fully connected search queue and recording it as the first current point until the fully connected search queue is empty.

4. The method according to claim 1, characterized in that The steps of numbering the connected domains of the non-fully connected points by a breadth-first search method, saving the numbered grid points and the corresponding connected domain numbers to a grid point connected domain numbering recording system, and saving the merging relationship between different connected domains to the connected domain numbering system include: Determine connectivity based on connectivity requirements; Initialize a non-fully connected search queue, and use the connected domain number in the connected domain number counter after the full connection point search is completed as the second current connected domain number; Selecting a point from the non-fully connected points that has not been recorded by the grid point connected domain number recording system as a second starting point; Traversing the second adjacent points of the second starting point in all discrete velocity directions; When all the second adjacent points and the second starting point do not satisfy the connectivity condition of the connectivity, skip the second starting point, and return to the step of selecting a point from the non-fully connected points that has not been recorded by the grid connected domain number recording system as the second starting point; When at least one of the second adjacent points and the second starting point meets the connectivity condition of the connectivity, adding the second starting point to the non-fully connected search queue; Recording the coordinates of the second starting point and the second current connected domain number in the grid connected domain number recording system; Performing a breadth-first search on the non-fully connected search queue, and during the search process, recording the grid points and the corresponding connected domain numbers into a search grid point connected domain number recording system, and recording the merging relationship between connected domains into a connected domain numbering system; Incrementing the second current connected domain number in the connected domain number counter; Return to the step of selecting a point from the non-fully connected points that has not been recorded by the grid connected domain number recording system as the second starting point, until all points in the non-fully connected points are recorded by the grid connected domain number recording system.

5. The method according to claim 4, characterized in that The step of performing a breadth-first search on the non-fully connected search queue, and recording the grid points and the corresponding connected domain numbers into the search grid point connected domain number recording system during the search process, and recording the merging relationship between the connected domains into the connected domain numbering system comprises: Popping a point from the non-fully connected search queue and recording it as the second current point; Traversing the third adjacent points of the second current point in all discrete velocity directions; When the third adjacent point in the currently traversed discrete speed direction and the second current point meet the connectivity condition of the connectivity and the third adjacent point has not been recorded by the grid point connected domain number recording system, the grid point connected domain number recording system records the third adjacent point and the second current connected domain number, and adds the third adjacent point to the non-fully connected search queue; When the third adjacent point in the currently traversed discrete speed direction and the second current point meet the connectivity condition of the connectivity and the third adjacent point has been recorded by the grid connected domain number recording system, the connected domain number corresponding to the third adjacent point and the second current connected domain number are recorded in the connected domain numbering system as a merge relationship; Return to the step of popping a point from the non-fully connected search queue and recording it as the second current point until the non-fully connected search queue is empty.

6. The method according to claim 1, characterized in that The connected domain numbering system includes an associative container and a serial container, wherein the associative container is used to record each connected domain number and the corresponding serial number, and the serial container is used to record the connected domain number after merging; The step of merging the connected domain numbers in the connected domain numbering system to obtain a target connected domain number comprises: Acquire the first connected domain number and the second connected domain number to be merged from the connected domain number system; When the first connected domain number and the second connected domain number are different, checking whether the first connected domain number and the second connected domain number are recorded in the associative container; When both the first connected domain number and the second connected domain number are recorded in the associative container, obtaining a first sequence number and a second sequence number corresponding to the first connected domain number and the second connected domain number from the associative container; updating the data in the associative container and the serial container according to the first sequence number and the second sequence number; When the data update is completed, the connected domain number queues in the sequential container are merged according to the connected domain numbers in the associative container; When the merging is completed, the process returns to the step of obtaining the first connected domain number and the second connected domain number to be merged from the connected domain numbering system until all connected domain numbers in the connected domain numbering system are traversed to obtain the target connected domain number.

7. The method according to claim 6, characterized in that The step of updating the data in the associative container and the serial container according to the first sequence number and the second sequence number comprises: When the first sequence number is different from the second sequence number, traverse the elements in the queue with the second sequence number in the sequential container, and update the sequence number corresponding to the element in the associative container to the first sequence number; Insert all elements in the queue with the second sequence number into the queue with the first sequence number in the sequential container; Deleting the queue with the second sequence number from the serial container; When the deletion is completed, the associative container is traversed, and all sequence numbers greater than the second sequence number are sorted in descending order to complete the data update in the associative container and the serial container.

8. The method according to claim 6, characterized in that When the data update is completed, the step of merging the connected domain number queues in the sequential container according to the connected domain numbers in the associative container includes: When the data update is completed, the first connectivity domain number is recorded in the associative container, and the second connectivity domain number is not recorded in the associative container, recording the second connectivity domain number into the connectivity domain number queue where the first connectivity domain number is located; When the second connectivity domain number is recorded in the associative container and the first connectivity domain number is not recorded in the associative container, recording the first connectivity domain number into a connectivity domain number queue where the second connectivity domain number is located; When neither the first connected domain number nor the second connected domain number is recorded in the associative container, the number of connected domains in the sequential container is used as a new connected domain serial number; Recording the first connected domain number, the second connected domain number and the new connected domain sequence number in the associative container; A new queue including the first connected domain number and the second connected domain number is added to the serial container.

9. The method according to claim 1, characterized in that After the step of merging the connected domain numbers in the connected domain numbering system to obtain the target connected domain number, the method further includes: Traversing the non-fully connected points, merging the target connected domain numbers according to the three-dimensional connection relationship between the non-fully connected points and adjacent connected domains, to obtain a first reference connected domain number; Deleting the to-be-deleted number in the first reference connected domain number to obtain a second reference connected domain number, wherein the to-be-deleted number is a connected domain number corresponding to a connected domain having a grid point number less than a preset grid point number threshold; The target connected domain number is updated according to the second reference connected domain number.

10. The method according to claim 9, characterized in that The step of traversing the non-fully connected points and merging the target connected domain numbers according to the three-dimensional connection relationship between the non-fully connected points and the adjacent connected domains to obtain the first reference connected domain number comprises: Traversing the non-fully connected points, and recording the connection relationship between each non-fully connected point and surrounding adjacent connected domains; When the connection relationship is a three-dimensional connection relationship, recording a first connected domain of the non-fully connected points corresponding to the connection relationship and a second connected domain corresponding to the connection relationship; Traversing all connected directions of the non-fully connected points, and recording a set of connected grid points in the connected directions that belong to the first connected domain or the second connected domain; When the connected grid point set merges the non-fully connected points to satisfy grid volume connectivity, the connected domain numbers corresponding to the first connected domain and the second connected domain in the target connected domain number are merged to obtain a first reference connected domain number.

11. The method according to claim 9, characterized in that After the step of updating the target connected domain number according to the second reference connected domain number, the method further includes: Marking the grid points in the connected domain corresponding to the second reference connected domain number as valid connected domain grid points; Traversing the adjacent grid points in all connected directions of the grid points of the effective connected domain; When the adjacent grid point is the valid connected domain grid point and the connected domain number of the valid connected domain grid point is different from the connected domain number of the adjacent grid point, recording the connected domain boundary according to the valid connected domain grid point, the connected domain number of the valid connected domain grid point, the connection direction between the valid connected domain grid point and the adjacent grid point, and the connected domain number of the adjacent grid point; When the adjacent grid point is not the valid connected domain grid point, the degenerate point connected domain boundary is recorded according to the valid connected domain grid point, the connected domain number to which the valid connected domain grid point belongs, and the connection direction between the valid connected domain grid point and the adjacent grid point.

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