Vehicle infrared radiation simulation method based on temperature field mapping

Abstract

A vehicle infrared radiation simulation method based on temperature field mapping comprises the following steps: S1, performing thermal influence analysis on an original vehicle model to generate a simplified vehicle model; s2, grid division is carried out on the simplified vehicle model, and a temperature field of the simplified vehicle model is solved by adopting a numerical analysis method; s3, respectively extracting node coordinates of the original vehicle model and the simplified vehicle model, respectively calculating geometric centers of the original vehicle model and the simplified vehicle model, and realizing spatial registration of the original vehicle model and the simplified vehicle model through translation transformation; s4, mapping the temperature value of the simplified vehicle model to a corresponding grid node of the original vehicle model by adopting a KNN algorithm based on a KD tree and combining an inverse distance weighted interpolation algorithm; and S5, on the basis of the mapped original vehicle model temperature field data, in combination with the material emissivity and the environmental radiation parameters, calculating the infrared radiation characteristics through a ray tracing method. According to the method, the calculation efficiency can be remarkably improved while the simulation precision is ensured, and the advantages are obvious.

Description

Technical Field

[0001] This invention relates to the field of computational thermodynamics and infrared radiation characteristic simulation technology, specifically a vehicle infrared radiation simulation method based on temperature field mapping. Background Technology

[0002] In military, security, and other fields, the simulation of the infrared radiation characteristics of vehicle targets is crucial. The first step in the simulation is to calculate the temperature field, which is a computationally intensive process. Its accuracy and efficiency directly determine the realism of the final infrared image.

[0003] The current mainstream approach is to create a high-fidelity 3D model of the vehicle, mesh it, and then use computational fluid dynamics (CFD) or solar radiation calculation software to solve for the temperature field. However, high-fidelity models contain a large number of complex and intricate components (such as screws, wiring harnesses, and fine blades of the cooling grille), which leads to a dramatic increase in the number of meshes (reaching millions or even tens of millions), resulting in lengthy computation times and making the process difficult to complete.

[0004] To improve efficiency, simulation models are often simplified by removing minor components that have little impact on the overall temperature distribution. However, this method has an inherent drawback: the simplified model is geometrically inconsistent with the original complex model, meaning that the temperature field obtained based on the simplified model cannot be directly used for subsequent infrared radiation calculations of the original complex model, thus reducing the fidelity and reliability of the final simulation results.

[0005] Therefore, it is essential to propose a solution that can significantly improve the efficiency of temperature field calculation and ultimately obtain a high-fidelity model with accurate temperature distribution.

[0006] It is understood that the above statements only provide background information related to the present invention and do not necessarily constitute prior art. Summary of the Invention

[0007] Based on the aforementioned technical problems, the purpose of this invention is to provide a vehicle infrared radiation simulation method based on temperature field mapping, which can significantly improve computational efficiency while ensuring simulation accuracy.

[0008] To achieve the above objectives, this invention proposes a vehicle infrared radiation simulation method based on temperature field mapping, comprising the following steps: S1, performing thermal impact analysis on the original vehicle model, selecting key thermal components based on the degree of influence of each component on the overall temperature field, and removing other components besides the key thermal components to generate a simplified vehicle model; S2, meshing the simplified vehicle model and solving its temperature field using numerical analysis methods; S3, extracting the node coordinates of the original vehicle model and the simplified vehicle model respectively, calculating their geometric centers respectively, and using the geometric centers as reference points, achieving spatial registration between the two through translation transformation; S4, based on the spatially registered node coordinates, using the KD-tree-based nearest neighbor search (KNN) algorithm, combined with the inverse distance weighted interpolation algorithm, mapping the temperature values ​​of the simplified vehicle model to the corresponding mesh nodes of the original vehicle model; S5, based on the mapped temperature field data of the original vehicle model, and combined with material emissivity and environmental radiation parameters, calculating its infrared radiation characteristics using ray tracing.

[0009] Preferably, in step S1, the principle for generating a simplified vehicle model is as follows: based on engineering experience or thermal sensitivity analysis, identify and delete components whose impact on the overall temperature field is less than a preset threshold, and generate a simplified vehicle model for temperature field calculation.

[0010] Preferably, in step S2, the mesh is divided into a non-uniform mesh, and the mesh type and mesh density are determined according to the simulation accuracy requirements.

[0011] Preferably, in step S2, the numerical analysis method is the finite element method or the finite volume method.

[0012] Preferably, in step S3, the calculation formula for spatial registration is as follows: in, This is the geometric center point of the original vehicle model; To simplify the geometric center point of the vehicle model; To simplify the coordinates of any node in the vehicle model; The coordinates of the corresponding nodes in the simplified vehicle model after registration.

[0013] Preferably, step S4 specifically includes the following steps: using the KDTree function, taking the coordinates of all nodes of the simplified vehicle model registered in step S3 as input, to construct a KD-tree index structure; traversing each grid node of the original vehicle model, using the three-dimensional coordinates of each grid node as a query point, performing the nearest neighbor search (KNN) algorithm in the KD-tree index structure to find the K nodes in the simplified vehicle model closest to the query point; using the inverse distance weighted interpolation algorithm, and based on the temperature values ​​of the K nearest neighbor nodes and their Euclidean distance to the query point, calculating the mapped temperature value of the corresponding node in the original vehicle model.

[0014] Preferably, the inverse distance weighted interpolation algorithm is calculated as follows: in, The temperature of the original vehicle model node is the unknown value. It is the first j The temperature of the nearest neighbor node, It's weight. Is the query point to the number j The distance between the nearest neighbors, p is an exponential parameter.

[0015] Preferably, K is an integer greater than or equal to 3 and less than or equal to 5.

[0016] Compared with existing technologies, the vehicle infrared radiation simulation method based on temperature field mapping proposed in this invention has at least the following advantages: (1) The method provided by the present invention preserves the true geometric features of the target to the greatest extent while ensuring computational efficiency, thus ensuring the credibility of the simulation results; (2) The method provided by the present invention uses KD tree and KNN algorithm for spatial interpolation, which can transfer the temperature field from one geometric shape to another very accurately, and the error is controllable; (3) The method provided by the present invention is not only applicable to vehicles, but can also be extended to any complex target that requires thermal-infrared joint simulation, such as aircraft, ships, and buildings, and has wide applicability. Attached Figure Description

[0017] Figure 1 This is a flowchart of the vehicle infrared radiation simulation method based on temperature field mapping in this invention. Detailed Implementation

[0018] The present invention will be further described below with reference to the accompanying drawings and by providing a detailed description of a preferred embodiment.

[0019] It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions. They are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention, and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationship, or adjustments to the size should still fall within the scope of the technical content disclosed in the present invention, provided that they do not affect the effects and objectives that the present invention can produce.

[0020] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items.

[0021] like Figure 1 As shown, this invention provides a vehicle infrared radiation simulation method based on temperature field mapping, specifically including the following steps: S1. Perform thermal impact analysis on the original vehicle model to screen out thermally critical components based on the degree of influence of each component on the overall temperature field, and remove other components except for the thermally critical components to generate a simplified vehicle model for simulation. S2. Mesh the simplified vehicle model and solve its temperature field using numerical analysis methods; S3. Extract the node coordinates of the original vehicle model and the simplified vehicle model respectively, calculate their geometric centers respectively, and use their geometric center points as reference points to achieve spatial registration of the two through translation transformation. S4. Based on the node coordinates after spatial registration, the nearest neighbor search (KNN) algorithm based on KD tree (k-dimensional) is used to map the temperature values ​​of the simplified vehicle model to the corresponding grid nodes of the original vehicle model. S5. Based on the temperature field data of the original vehicle model after mapping, and combined with the material emissivity and environmental radiation parameters, its infrared radiation characteristics are calculated by ray tracing.

[0022] Furthermore, in step S1, the specific implementation method of step S1 is as follows: First, import the original vehicle model into the 3D modeling tool; second, based on engineering experience or thermal sensitivity analysis, identify and delete components whose impact on the overall temperature field is less than a preset threshold, such as screws, decorative decals, and non-structural small holes inside the vehicle; finally, generate a simplified vehicle model for temperature field calculation and export it in a general format for 3D models. In a preferred embodiment of the present invention, the general format of the 3D model is .stp, .igs, etc.

[0023] Furthermore, in step S2, the mesh is divided into a non-uniform mesh, the numerical analysis method includes the finite element method or the finite volume method, and the temperature field is a steady-state temperature field or a transient temperature field.

[0024] Specifically, step S2 is implemented as follows: the simplified vehicle model generated in step S1 is imported into the thermal simulation software and initialized, including setting the computational domain and boundary conditions; a non-uniform mesh is generated, and the mesh type and mesh density are determined according to the simulation accuracy requirements; the solver of the thermal simulation software is run until convergence, and a temperature field result file is output. The temperature field result file contains the coordinates and temperature values ​​of each mesh node of the simplified vehicle model.

[0025] Furthermore, in step S3, the geometric center point of the original vehicle model is obtained by taking the arithmetic mean of the coordinates of all nodes of both the original vehicle model and the simplified vehicle model as their respective geometric centers. and the simplified geometric center point of the vehicle model It is understandable that the original vehicle model and the simplified vehicle model are meshed using the same meshing method to generate mesh nodes.

[0026] The translation transformation is achieved by subtracting the geometric center coordinates from all node coordinates of the simplified vehicle model and adding the geometric center coordinates of the original model. This achieves spatial alignment (registration) between the two models. The calculation formula is as follows: in, To simplify the coordinates of any node in the vehicle model; The coordinates of the corresponding nodes in the simplified vehicle model after registration.

[0027] Furthermore, in step S4, the specific implementation method of step S4 is as follows: First, using the KDTree function, the coordinates of all nodes of the simplified vehicle model registered in step S3 are used as input to construct a KD-tree index structure; then, each grid node of the original vehicle model is traversed, and the three-dimensional coordinates of each grid node are used as query points. The nearest neighbor search (KNN) algorithm is executed in the KD-tree index structure to find the K (K is usually 3-5) nodes in the simplified vehicle model that are closest to the query point; finally, the inverse distance weighted interpolation algorithm is used, and the mapped temperature value of the corresponding node in the original vehicle model is calculated based on the temperature values ​​of the K nearest neighbor nodes and their Euclidean distance to the query point; wherein, the calculation formula is: in, The temperature of the original vehicle model node is the unknown value. It is the firstj The temperature of the nearest neighbor node, It's weight. Is the query point to the number j The distance between the nearest neighbors, p is an exponential parameter (usually taken as 2).

[0028] Finally, the calculated temperature values ​​are assigned to the corresponding nodes of the original vehicle model. Thus, after the loop ends, an original vehicle model containing complete temperature field data is obtained.

[0029] Furthermore, in actual simulation, step S5 is implemented as follows: the original vehicle model with temperature field data is imported into the infrared simulation software, corresponding material property parameters and boundary conditions are set for different components, and parameters such as atmospheric environment, observation angle, and band are further set. Then, infrared radiation calculation is performed to generate the final infrared radiation characteristic data.

[0030] In summary, this invention provides a vehicle infrared radiation simulation method based on temperature field mapping. By selecting key thermal components and constructing a simplified model, it combines non-uniform mesh generation and numerical analysis to achieve efficient temperature field solving. Then, spatial registration and KD-tree search are used to accurately map temperature data from the simplified model to the original model, ultimately obtaining infrared radiation characteristic data through simulation. This method ensures computational efficiency while preserving the true geometric features of the target to the greatest extent, guaranteeing the reliability of the simulation results. Furthermore, this method is not only applicable to vehicles but can also be extended to any complex target requiring thermal-infrared co-simulation, such as aircraft, ships, and buildings, demonstrating broad applicability.

[0031] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for simulating vehicle infrared radiation based on temperature field mapping, characterized in that, Includes the following steps: S1. Perform thermal impact analysis on the original vehicle model, select the thermally critical components based on the degree of influence of each component on the overall temperature field, and remove other components except for the thermally critical components to generate a simplified vehicle model. S2. Mesh the simplified vehicle model and solve its temperature field using numerical analysis methods; S3. Extract the node coordinates of the original vehicle model and the simplified vehicle model respectively, calculate their geometric centers respectively, and use their geometric center points as reference points to achieve spatial registration of the two through translation transformation. S4. Based on the spatially registered node coordinates, the KNN algorithm based on KD tree is used, combined with the inverse distance weighted interpolation algorithm, to map the temperature values ​​of the simplified vehicle model to the corresponding grid nodes of the original vehicle model. S5. Based on the temperature field data of the original vehicle model after mapping, and combined with the material emissivity and environmental radiation parameters, its infrared radiation characteristics are calculated by ray tracing.

2. The vehicle infrared radiation simulation method based on temperature field mapping as described in claim 1, characterized in that, In step S1, the principle for generating a simplified vehicle model is as follows: Based on engineering experience or thermal sensitivity analysis, identify and remove components whose impact on the overall temperature field is less than a preset threshold, and generate a simplified vehicle model for temperature field calculation.

3. The vehicle infrared radiation simulation method based on temperature field mapping as described in claim 1, characterized in that, In step S2, the mesh is divided into a non-uniform mesh, and the mesh type and mesh density are determined according to the simulation accuracy requirements.

4. The vehicle infrared radiation simulation method based on temperature field mapping as described in claim 1, characterized in that, In step S2, the numerical analysis method adopts the finite element method or the finite volume method.

5. The vehicle infrared radiation simulation method based on temperature field mapping as described in claim 1, characterized in that, In step S3, the calculation formula for spatial registration is as follows: in, This is the geometric center point of the original vehicle model; To simplify the geometric center point of the vehicle model; To simplify the coordinates of any node in the vehicle model; The coordinates of the corresponding nodes in the simplified vehicle model after registration.

6. The vehicle infrared radiation simulation method based on temperature field mapping as described in claim 1, characterized in that, Step S4 specifically includes the following steps: Using the KDTree function, the coordinates of all nodes of the simplified vehicle model registered in step S3 are used as input to construct a KD tree index structure; Traverse each grid node of the original vehicle model, using the three-dimensional coordinates of each grid node as the query point, and execute the nearest neighbor search (KNN) algorithm in the KD-tree index structure to find the K nodes in the simplified vehicle model that are closest to the query point. An inverse distance weighted interpolation algorithm is used, and the mapped temperature value of the corresponding node in the original vehicle model is calculated based on the temperature values ​​of the K nearest neighbor nodes and their Euclidean distance to the query point.

7. The vehicle infrared radiation simulation method based on temperature field mapping as described in claim 6, characterized in that, The inverse distance weighted interpolation algorithm is calculated as follows: in, The temperature of the original vehicle model node is the unknown value. It is the first j The temperature of the nearest neighbor node, It's weight. Is the query point to the number j The distance between the nearest neighbors, p is an exponential parameter.

8. The vehicle infrared radiation simulation method based on temperature field mapping as described in claim 6, characterized in that, K is an integer greater than or equal to 3 and less than or equal to 5.

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