Grid cell fitting degree inspection method, system and equipment and storage medium

Abstract

The invention relates to a grid cell fitting degree inspection method, system and equipment and a storage medium. All shell units and all geometric surfaces of a part are obtained according to a CAD geometric model and a CAE model of the part; each shell unit is vertically projected on the geometric surface to obtain a corresponding local area on the geometric surface, so that the local judgment of the geometric surface can be subsequently carried out, the condition that one grid unit cannot cover the minimum geometric surface is avoided, the judgment precision is improved by the local judgment, and the real fitting condition can be better met; in addition, node vertical distances between all nodes of each shell unit and corresponding points in a local area are compared with a preset threshold value, so that the normal vector of each node and the normal vector of the corresponding points in the local area are the same, have no difference and are not influenced by a curved surface, the accuracy of a fitting inspection result can be ensured, the automatic inspection of the grid fitting degree is realized, and the efficiency is improved. The grid quality of the CAE model is improved; and outputting a visual fitting degree distribution diagram, and visually displaying the fitting condition.

Description

Technical Field

[0001] This application relates to the field of automotive body structure performance development technology, and in particular to a method, system, device and storage medium for checking the fit of grid cells. Background Technology

[0002] Currently, FEA, short for Finite Element Analysis, is a numerical simulation technique based on the finite element method used to solve approximate solutions to complex engineering problems. FEA discretizes a continuum into a finite number of elements (such as triangles, quadrilaterals, tetrahedrons, etc.) and applies physical laws and boundary conditions to these elements to simulate and predict the behavior of physical fields such as structures, fluids, heat, and electromagnetism. FEA is applicable to engineering and scientific problems in multiple fields, including solid mechanics, fluid mechanics, thermodynamics, electromagnetism, and acoustics, particularly in aerospace, automotive, civil engineering, and medical devices.

[0003] As the automotive industry delves deeper into structural mechanics research, Finite Element Analysis (FEA) is gaining increasing favor among automakers due to its powerful analytical methods that enable rapid design and iterative optimization. An FEA model is composed of small, simple elements, which together form a finite element model that conforms to the geometric shape. The fit between the elements and the geometric model is one of the most crucial factors influencing finite element analysis.

[0004] In some related technologies, the fit between each mesh cell and the geometric model is checked by using the distance between the center point or normal vector of the mesh cell and the corresponding geometric model region. However, the following problems exist:

[0005] (1) When the minimum geometry corresponds to multiple mesh elements (the minimum geometry is greater than one mesh element), it is obviously flawed to use one mesh element to represent the fit of other mesh elements with the minimum geometry.

[0006] (2) When the minimum geometric surface of a part has a curved surface, the presence of the curved surface causes a large deviation between the center point of the mesh or the normal vector of the mesh and the normal vector of the curved surface. This is because the normal vector of the curved surface is constantly changing at different positions, and the result of the fit judgment does not conform to the actual situation. In addition, for the minimum geometric surface with continuous complex curved surfaces, the accuracy of the inspection is even more problematic. Summary of the Invention

[0007] This application provides a method, system, device, and storage medium for checking the fit of mesh units, in order to solve the problem in the related art that when the smallest geometric surface of a part is curved, the curved surface causes a large deviation between the mesh center point or the mesh normal vector and the curved surface geometric normal vector, resulting in errors in the fit inspection results.

[0008] Firstly, a method for checking the mesh cell fit is provided, which includes:

[0009] Based on the CAD geometric model and CAE model of the part, all shell elements and all geometric surfaces of the part are obtained.

[0010] Each shell element is vertically projected onto the geometric surface to obtain the corresponding local region on the geometric surface; the vertical distance between each shell element and the corresponding point in the local region is calculated.

[0011] Based on the preset threshold value and the vertical distance between all nodes, the fit of all nodes in each shell unit is obtained.

[0012] In some embodiments, the fit of all nodes in each shell unit is obtained based on a preset threshold value and the vertical distance between all nodes, including the following steps:

[0013] Determine whether the vertical distance between all nodes of a shell element is greater than a preset threshold value;

[0014] If the vertical distance between at least one node is greater than the preset threshold value, the fit requirement is not met; otherwise, the fit requirement is met.

[0015] Following the steps described above to determine whether the vertical distance between all nodes of a shell unit is greater than a preset threshold value, the remaining shell units are checked to obtain the fit of the entire part.

[0016] In some embodiments, when the fit requirement is not met, the local area of ​​the shell unit corresponding to the geometric surface is marked with a first set color;

[0017] When the fit requirement is met, the local area of ​​the shell unit on the geometric surface is marked with a second set color;

[0018] The annotation information of all local areas is collected, and then a visual mapping of the fit distribution is generated, and a list of local areas that do not meet the fit requirements is output.

[0019] In some embodiments, obtaining the preset threshold value includes the following steps:

[0020] Determine the geometry type of the local region on the geometric surface corresponding to each shell element;

[0021] When the geometric surface type corresponding to the shell unit is a plane, the preset threshold value corresponding to the shell unit is the first threshold value;

[0022] When the geometric surface type corresponding to the shell element is a curved surface, the preset threshold value corresponding to the shell element is the second threshold value;

[0023] Repeat the above steps to obtain the preset threshold value for each shell unit.

[0024] In some embodiments, when the geometry of the shell element is a curved surface, the following steps are also included:

[0025] Obtain the geometric curvature of the local region corresponding to the shell element on the geometric surface, and then determine the second threshold based on the geometric curvature.

[0026] In some embodiments, based on the CAD geometric model and CAE model of the part, all shell elements and all geometric surfaces of the part are obtained, including the following steps:

[0027] Establish CAD geometric models and CAE models of the parts;

[0028] Get all shell elements of the CAE model, group them together, and the shell elements include quadrilateral shell elements and triangular shell elements; get all geometric surfaces of the CAD geometric model and group them together.

[0029] In some embodiments, the following steps are included before obtaining all shell elements of the CAE model:

[0030] Determine whether the CAE model is a volume element model;

[0031] If so, then if it is a volume element model, form a shell element on the surface of the volume element model and remove it to obtain a CAE mesh model.

[0032] Secondly, a grid cell fit inspection system is provided, the grid cell fit inspection system comprising:

[0033] The first module is used for CAD and CAE models of parts to obtain all shell elements and all geometric surfaces of the relevant parts.

[0034] The second module is used to project each shell element vertically onto the geometric surface to obtain the corresponding local region on the geometric surface; and to calculate the vertical distance between all nodes of each shell element and the corresponding points in the local region.

[0035] The third module is used to obtain the fit of all nodes of each shell unit based on a preset threshold value and the vertical distance between all nodes.

[0036] Thirdly, a grid cell fitability inspection device is provided, the grid cell fitability inspection device including a processor, a memory, and a grid cell fitability inspection program stored in the memory and executable by the processor, wherein when the grid cell fitability inspection program is executed by the processor, the steps of the grid cell fitability inspection method are implemented.

[0037] Fourthly, a computer-readable storage medium is provided, wherein a grid cell fit checking program is stored on the computer-readable storage medium, wherein when the grid cell fit checking program is executed by a processor, the steps of the grid cell fit checking method are implemented.

[0038] The beneficial effects of the technical solution provided in this application include:

[0039] This application provides a method, system, device, and storage medium for checking the mesh unit fit. Based on the CAD and CAE geometric models of the part, all shell units and geometric surfaces of the part are obtained. Each shell unit is vertically projected onto the geometric surface to obtain a corresponding local region on the geometric surface. This allows for subsequent local judgment of the geometric surface, avoiding situations where a single mesh unit cannot cover the smallest geometric surface. Furthermore, local judgment increases the accuracy of the judgment and better reflects the actual fit. In addition, the vertical distance between all nodes of each shell unit and corresponding points in the local region is compared with a preset threshold value to ensure that the normal vector of each node is the same as the normal vector of the corresponding point in the local region, with no discrepancies. This results in higher accuracy, is unaffected by curved surfaces, guarantees the accuracy of the fit check results, achieves automated mesh fit checking, and improves the mesh quality of the CAE model. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 A schematic diagram illustrating the general flow of the mesh cell fit inspection method provided in the embodiments of this application;

[0042] Figure 2 This is a schematic diagram illustrating the specific process of the mesh cell fit inspection method provided in the embodiments of this application;

[0043] Figure 3 This is an example diagram illustrating the distribution of the visual fit degree provided in the embodiments of this application. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] It should be understood in connection with this application that:

[0046] 1. Mesh nodes define the spatial location of geometry. In finite element analysis, the shape and behavior of a physical object are achieved by dividing it into simple elements (such as triangles, quadrilaterals, hexahedrons, etc.), and the vertices of these elements are nodes.

[0047] 2. Shell elements are mesh elements.

[0048] 3. In CAE models, the volume element model refers to an assembly of imaginary three-dimensional solid elements that divide a continuum into a finite number of elements. These elements are interconnected at their vertices, forming nodes. The volume element model plays a crucial role in finite element analysis (FEA).

[0049] When checking the fit between each mesh cell and the geometric model, the distance between the center point or normal vector of the mesh cell and the corresponding geometric model region is used to determine whether the fit is good. However, the following problems exist:

[0050] (1) When the minimum geometry corresponds to multiple mesh elements (the minimum geometry is greater than one mesh element), it is obviously flawed to use one mesh element to represent the fit of other mesh elements with the minimum geometry.

[0051] (2) When the minimum geometric surface of a part has a curved surface, the presence of the curved surface causes a large deviation between the center point of the mesh or the normal vector of the mesh and the normal vector of the curved surface. This is because the normal vector of the curved surface is constantly changing at different positions, and the result of the fit judgment does not conform to the actual situation. In addition, for the minimum geometric surface with continuous complex curved surfaces, the accuracy of the inspection is even more problematic.

[0052] Firstly, a method for checking the fit of mesh elements is provided to solve the problem in related technologies where, when the smallest geometric surface of a part is curved, the curved surface causes a large deviation between the mesh center point or the mesh normal vector and the surface geometric normal vector, resulting in errors in the fit check results.

[0053] See Figures 1-3 A method for checking the fit of mesh cells, comprising the following steps:

[0054] Step 100: Based on the CAD geometric model and CAE model of the part, obtain all shell elements and all geometric surfaces of the part.

[0055] Step 200: Project each shell element vertically onto the geometric surface to obtain the corresponding local region on the geometric surface; calculate the vertical distance between all nodes of each shell element and the corresponding points in the local region;

[0056] Step 300: Based on the preset threshold value and the vertical distance between all nodes, obtain the fitting degree of all nodes of each shell unit.

[0057] Through the above steps, all shell elements and all geometric surfaces of the part are obtained based on the CAD geometric model and CAE model of the part. Each shell element is vertically projected onto the geometric surface to obtain the corresponding local area on the geometric surface. This allows for subsequent local judgment of the geometric surface, avoiding the situation where a single mesh element cannot cover the smallest geometric surface. Furthermore, local judgment increases the accuracy of the judgment and is more consistent with the actual fit. In addition, the vertical distance between all nodes of each shell element and the corresponding points in the local area is compared with a preset threshold value to ensure that the normal vector of each node is the same as the normal vector of the corresponding point in the local area, with no difference. This results in higher accuracy, is unaffected by curved surfaces, ensures the accuracy of the fit check results, realizes automated mesh fit check, and improves the mesh quality of the CAE model.

[0058] In some preferred embodiments, step 100 specifically includes the following steps:

[0059] This invention is based on the CAE preprocessing software ANSA, which has an open development platform that supports the Python language, enabling secondary development programs using Python. This invention utilizes the built-in Python language in ANSA to write automated programs.

[0060] I. You need to install ANSA v23.0.0 or a later version.

[0061] II. Import the CAE model into ANSA software after meshing and when the mesh nodes need to be verified. The file contains both the CAD geometric model (for sheet metal parts, the mid-surface has been extracted) and the CAE finite element model, as well as the association information between the CAD and CAE model parts (generally, after meshing, ANSA will associate them by default).

[0062] III. In the CAE model, the Properties List is iterated through to all parts that require mesh node verification.

[0063] IV. Calling the SHOW ONLY module only displays the currently looping part, which includes both the CAD geometric model and the CAE model.

[0064] V. Determine whether the CAE model of this part is a solid element model.

[0065] If so, then if it is a volume element model, form a shell element on the surface of the volume element model and remove it to obtain a CAE mesh model.

[0066] VI. Group all shell elements (quadrilaterals, triangles) in the CAE mesh model of the current part into one group, and group all geometric faces in the CAD model of the current part into another group; each part consists of many geometric faces, and correspondingly, many CAE meshes. The purpose of grouping is to allow the CAE and CAD models to be traversed and compared in a loop to find the nearest geometric face.

[0067] This application can be understood as follows: the normal vector of a single mesh (containing quadrilaterals and triangles) can only represent the average spatial position of three points. However, this invention compares the position of each point individually, which allows for control over the position of each point. Furthermore, some techniques may have shortcomings in the position of the normal vector's center point relative to the target CAD data. This is because the positions of a single mesh (3 or 4 points) may deviate from the CAD geometry, but the center point remains on the surface, thus the fit is considered good despite the actual deviation. Although this invention uses more comparison points than some techniques, the correlation between the CAE mesh and CAD data has already been established through previous related technologies, thus limiting the comparison to a local area and maintaining high efficiency.

[0068] In some preferred embodiments, step 300, based on a preset threshold value and the vertical distance between all nodes, obtains the fit of all nodes in each shell unit, specifically including the following steps:

[0069] Step 3000-1: Determine whether the vertical distance between all nodes of a shell element is greater than a preset threshold value;

[0070] Step 3000-2: If the vertical distance between at least one node is greater than the preset threshold value, the fit requirement is not met; otherwise, the fit requirement is met.

[0071] Step 3000-3: Following the steps described above for determining whether the vertical distance between all nodes of a shell unit is greater than the preset threshold value, check the remaining shell units to obtain the fit of the entire part.

[0072] The above steps can realize the fitting status of all nodes of a shell element. Since the shell element is the smallest mesh, the fitting status of all its nodes can most realistically represent the fitting status. As the smallest mesh, it greatly reduces the influence of the curved surface.

[0073] Furthermore, to significantly reduce manual workload and save time on manual visual inspection by automating the inspection of mesh fit, the following settings are implemented:

[0074] It also includes step 3000-4, where if the fit requirement is not met, the local area of ​​the shell unit on the geometric surface is marked with a first set color;

[0075] When the fit requirement is met, the local area of ​​the shell unit on the geometric surface is marked with a second set color;

[0076] The annotation information of all local areas is collected, and then a visual mapping of the fit distribution is generated, and a list of local areas that do not meet the fit requirements is output.

[0077] The above steps ultimately output a visual mapping of mesh fit distribution, which intuitively displays the fit status. Additionally, a list of local areas meeting the fit requirements can be output separately, allowing analysts to directly understand the specific situation without needing to check each area individually. This significantly reduces manual workload and facilitates rapid modifications by engineers. Furthermore, automated mesh fit checks improve the mesh quality of the CAE model, significantly contributing to the accuracy of finite element analysis. The entire vehicle model is processed in 20 minutes, saving 8 hours of manual visual inspection.

[0078] To achieve rapid and efficient CAE simulation modeling of the entire vehicle, the above-described mesh element fit checking method automates a large amount of repetitive and error-prone mesh checking work, greatly improving efficiency, controlling mesh quality, and reducing modeling error rate. This invention patent covers collision safety, rigidity and durability, and NVH, exhibiting high versatility; it can automatically compare FEA mesh models with CAD geometric models; and it can automatically and visually filter out meshes with large geometric deviations.

[0079] In some preferred embodiments, when the geometric surface has continuous curved surfaces, the following settings are made to achieve rapid and accurate inspection of fit and to improve the versatility of this inspection method:

[0080] Obtaining the preset threshold value includes the following steps:

[0081] Determine the geometry type of the local region on the geometric surface corresponding to each shell element;

[0082] When the geometric surface type corresponding to the shell unit is a plane, the preset threshold value corresponding to the shell unit is the first threshold value;

[0083] When the geometric surface type corresponding to the shell unit is a curved surface, the preset threshold value corresponding to the shell unit is the second threshold value; when the geometric surface type corresponding to the shell unit is a curved surface, the following steps are also included: obtaining the geometric curvature of the local region corresponding to the shell unit on the geometric surface, and then determining the second threshold value based on the geometric curvature.

[0084] Repeat the above steps to obtain the preset threshold value for each shell unit.

[0085] The above allows for the setting of preset threshold values ​​(i.e., deviation). Since CAE meshes cannot always be 100% perfectly fitted, different deviations can be set for certain areas with continuous curvature and complexity. For example, for a single mesh, the deviation can be set to 0.5mm for curved surfaces and 0.1mm for planar surfaces.

[0086] Secondly, a grid cell fit inspection system is provided, the grid cell fit inspection system comprising:

[0087] The first module is used for CAD and CAE models of parts to obtain all shell elements and all geometric surfaces of the relevant parts.

[0088] The second module is used to project each shell element vertically onto the geometric surface to obtain the corresponding local region on the geometric surface; and to calculate the vertical distance between all nodes of each shell element and the corresponding points in the local region.

[0089] The third module is used to obtain the fit of all nodes of each shell unit based on a preset threshold value and the vertical distance between all nodes.

[0090] The functions of each module in the above-mentioned grid cell fit inspection device correspond to the steps in the above-mentioned grid cell fit inspection method embodiment, and their functions and implementation processes will not be described in detail here.

[0091] Thirdly, embodiments of this application provide a grid cell fit inspection device, which can be a personal computer (PC), laptop computer, server, or other device with data processing capabilities.

[0092] In this embodiment, the grid cell fit inspection device may include a processor, a memory, a communication interface, and a communication bus. The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0093] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting devices within the grid cell fit inspection equipment, as well as interfaces used for interconnecting the grid cell fit inspection equipment with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0094] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0095] The processor can be a general-purpose processor, which can call the grid cell fit checking program stored in the memory and execute the grid cell fit checking method provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the grid cell fit checking program is called can be referred to the various embodiments of the grid cell fit checking method of this application, and will not be repeated here.

[0096] Fourthly, embodiments of this application also provide a computer-readable storage medium.

[0097] The present application provides a computer-readable storage medium storing a grid cell fit checking program, wherein when the grid cell fit checking program is executed by a processor, it implements the steps of the grid cell fit checking method as described above.

[0098] The method implemented when the grid cell fit check procedure is executed can be referred to in various embodiments of the grid cell fit check method of this application, and will not be repeated here.

[0099] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0100] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0101] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0102] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0103] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0104] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0105] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for checking the fit of a grid unit, characterized in that: It includes: Based on the CAD geometric model and CAE model of the part, all shell elements and all geometric surfaces of the part are obtained; Project each shell element vertically onto the geometric surface to obtain the local area corresponding to the geometric surface; calculate the node vertical distances between all nodes of each shell element and the corresponding points in the local area; Based on the preset threshold value and the vertical distance of all nodes, the fit of all nodes of each shell element is obtained.

2. The method for checking the fit of a grid unit according to claim 1, wherein: Based on the preset threshold value and the vertical distance of all nodes, the fit of all nodes of each shell element is obtained, including the following steps: Determine whether the node vertical distance of all nodes of a shell element is greater than a preset threshold value; If the vertical distance of at least one node is greater than the preset threshold value, the fit requirement is not met; otherwise, the fit requirement is met; According to the above steps of determining whether the node vertical distance of all nodes of a shell element is greater than the preset threshold value, the remaining shell elements are checked to obtain the fit of the entire part.

3. The method for checking the fit of a grid unit according to claim 2, wherein: When the fit requirement is not met, the local area of ​​the shell element corresponding to the geometric surface is marked with the first set color; When the fit requirement is met, the local area of ​​the shell element corresponding to the geometric surface is marked with the second set color; The annotations of all local areas are collected to form a visual fit distribution map, and a list of local areas that do not meet the fit requirements is output.

4. The method for checking the fit of a grid unit according to claim 1, wherein: Obtaining the preset threshold value includes the following steps: Determine the geometric surface type of the local area corresponding to each shell element on the geometric surface; When the geometric surface type corresponding to the shell element is a plane, the preset threshold value corresponding to the shell element is a first threshold value; When the geometric surface type corresponding to the shell element is a curved surface, the preset threshold value corresponding to the shell element is a second threshold value; Repeat the above steps to obtain the preset threshold value corresponding to each shell element.

5. The method for checking the fit of a grid unit according to claim 4, wherein: When the geometric surface type corresponding to the shell element is a curved surface, the following steps are also included: The geometric curvature of the local area corresponding to the shell element on the geometric surface is obtained, and then the second threshold is determined according to the geometric curvature.

6. The method for checking the fit of a grid unit according to claim 1, wherein: Based on the CAD geometric model and CAE model of the part, all shell elements and all geometric surfaces of the part are obtained, including the following steps: Establish CAD geometry model and CAE model of parts; Get all shell elements of the CAE model and treat them as a group. Shell elements include quadrilateral shell elements and triangular shell elements. Get all geometric faces of the CAD geometric model and treat them as a group.

7. The method for checking the fit of a grid unit according to claim 6, wherein: Before obtaining all shell elements of the CAE model, the following steps are also included: Determine whether the CAE model is a volume unit model; If so, if it is a solid unit model, a layer of shell elements is formed on the surface of the solid unit model and detached to obtain a CAE mesh model.

8. A grid unit fit inspection system, characterized in that: The grid unit fit inspection system comprises: The first module is used to obtain all shell elements and all geometric surfaces of the parts based on the CAD geometric model and CAE model of the parts; The second module is used to vertically project each shell element onto the geometric surface to obtain a local area corresponding to the geometric surface; calculate the node vertical distances between all nodes of each shell element and corresponding points in the local area; The third module is used to obtain the fit of all nodes of each shell element based on a preset threshold value and the vertical distance of all nodes.

9. A grid unit fit inspection device, characterized in that: The grid unit fit inspection device includes a processor, a memory, and a grid unit fit inspection program stored in the memory and executable by the processor, wherein when the grid unit fit inspection program is executed by the processor, the steps of the grid unit fit inspection method as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a grid unit fit inspection program, wherein when the grid unit fit inspection program is executed by a processor, the steps of the grid unit fit inspection method according to any one of claims 1 to 7 are implemented.

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