CN109614732B

CN109614732B - Electromagnetic compatibility modeling method and device for object

Info

Publication number: CN109614732B
Application number: CN201811571165.9A
Authority: CN
Inventors: 童心; 王显赫
Original assignee: Beijing Jingwei Hirain Tech Co Ltd
Current assignee: Beijing Jingwei Hirain Tech Co Ltd
Priority date: 2018-12-21
Filing date: 2018-12-21
Publication date: 2023-05-19
Anticipated expiration: 2038-12-21
Also published as: CN109614732A

Abstract

The invention provides an electromagnetic compatibility modeling method and device of an object, wherein the method comprises the following steps: decomposing an object to be molded into an electrical connection and P component units; converting each assembly unit from a body structure into a surface structure consisting of a surface without thickness, and taking the converted assembly unit as a target assembly unit; determining at least one target unit plane corresponding to each target component unit, and constructing a component model of each component through the at least one target unit plane corresponding to each target component unit; constructing an equivalent circuit model of the electrical connection as a model of the electrical connection; and combining the component models of all the component units and the models of the electrical connection, wherein the combined models are used as electromagnetic compatibility simulation models of the objects to be molded. The electromagnetic compatibility modeling method and device for the object can ensure the accuracy of simulation calculation, can also improve the simulation calculation efficiency, is simple in execution of the modeling process, has strong operability, and is suitable for practical engineering application.

Description

Electromagnetic compatibility modeling method and device for object

Technical Field

The invention relates to the technical field of electromagnetic compatibility, in particular to an electromagnetic compatibility modeling method and device of an object.

Background

The electromagnetic compatibility analysis is carried out by using modeling simulation, and is a development trend of electromagnetic compatibility design of an electronic and electric system. The electromagnetic compatibility modeling simulation can obtain a quantized analysis result, evaluate the electromagnetic compatibility risk in the early design stage and locate the cause of the risk, so that the method has important significance in engineering development.

Implementation of electromagnetic compatibility modeling simulation includes two aspects of a model and an algorithm. The current electromagnetic compatibility simulation algorithm is mature, such as a finite integration method (Finite Integration Technique, FIT), a finite difference method (Finite Difference in Time Domain, FDTD) in a time domain algorithm, a moment method (Method of Moments, moM), a finite element method (Finite Element Method, FEM) in a frequency domain algorithm, and the like.

However, how to build the structure of the electronic and electric system as a model with accurate results and practical calculation amount in engineering is always a difficulty of electromagnetic compatibility modeling simulation in engineering practice, which becomes a limiting factor for the application of the electromagnetic compatibility modeling simulation engineering. It can be appreciated that the actual product often has a fine structure, and particularly for structures with larger and more complex sizes, such as automobiles, airplanes, locomotives, etc., the balance between calculation accuracy and accuracy is more difficult for electromagnetic compatibility modeling, and no reasonable and effective electromagnetic compatibility modeling method exists at present.

Disclosure of Invention

In view of this, the invention provides a modeling method and device for electromagnetic compatibility of an object, which are used for reasonably and effectively modeling the electromagnetic compatibility of the object to be modeled, and the technical scheme is as follows:

an electromagnetic compatibility modeling method of an object, comprising:

decomposing an object to be molded into electrical connection and P assembly units, wherein any assembly unit comprises at least one assembly, and P is determined according to the structure of the object to be molded;

converting each assembly unit from a body structure into a surface structure consisting of a surface without thickness, and taking the converted assembly unit as a target assembly unit;

determining at least one target unit plane corresponding to each target component unit, and constructing a component model of each target component unit through the at least one target unit plane corresponding to each target component unit, wherein a three-dimensional space in which one target component unit is positioned is divided into R unit cells, the size of each unit cell is set based on the highest frequency of electromagnetic compatibility problems to be focused, one target unit plane is one unit plane of Q unit planes defined on one unit cell in which component fragments to be modeled exist, one unit plane corresponds to one component fragment, R is determined based on the size of the three-dimensional space in which the corresponding target component unit is positioned and the size of each unit cell, and Q is a preset fixed value which is larger than 1;

Constructing an equivalent circuit model of the electrical connection as a model of the electrical connection;

and combining the component models of all the component units and the electrically connected models, wherein the combined models are used as electromagnetic compatibility simulation models of the objects to be molded.

Optionally, the determining at least one target unit plane corresponding to each target component unit includes:

for any target component unit:

dividing a three-dimensional space in which the target assembly unit is positioned into R unit cells; for any cell, determining whether component fragments needing to be modeled exist in the cell, if the component fragments needing to be modeled exist in the cell, determining target unit planes corresponding to the component fragments in the cell based on the correlation between Q unit planes defined on the cell and the component fragments in the cell respectively, so as to obtain target unit planes corresponding to all the component fragments of the target component unit respectively, and taking the target unit planes as at least one target unit plane corresponding to the target component unit;

to obtain at least one target unit plane corresponding to each target assembly unit.

Optionally, the determining whether the component segment to be modeled exists in the cell includes:

Intercepting component fragments of the target component unit inside the cell;

calculating the coverage rate of projection of the component segment of the target component unit in the cell on the surface of the cell in the preset direction on the projection surface;

and determining whether the component segment of the target component unit in the cell is a component segment needing modeling or not based on the coverage rate.

Optionally, the determining, based on the correlation between the Q unit planes defined on the unit cell and the component segments in the unit cell, the target unit plane corresponding to the component segments in the unit cell includes:

calculating the correlation coefficients of the Q unit planes defined on the unit cell and the component fragments in the unit cell respectively, wherein the correlation coefficients are used for representing the correlation degree of the unit planes and the component fragments;

and determining the unit plane corresponding to the maximum correlation coefficient in all the calculated correlation coefficients as the target unit plane corresponding to the component segment in the unit cell.

Optionally, the building the component model of each target component unit through at least one target unit plane corresponding to each target component unit includes:

for any target component unit:

Combining at least one target unit plane corresponding to the target assembly unit; traversing the cells divided by the three-dimensional space where the target component unit is located, and if component segments needing to be modeled exist in two adjacent cells, and target unit planes respectively corresponding to the two component segments in the two adjacent cells are discontinuous, and the target component unit passes through a common plane of the two adjacent cells, connecting target vertexes of the two target unit planes on the two adjacent cells to form a repair unit plane, wherein the target vertexes are vertexes positioned on the common plane;

to obtain a component model for each of the target component units.

Optionally, the electromagnetic compatibility modeling method further includes:

before combining the component models of all the component units and the electrically connected models, verifying whether each component model meets the preset precision requirement;

if the component models meet the preset precision requirement, executing the component models combining all the component units and the electrically connected model;

if the component model which does not meet the preset precision requirement exists, the size of the cell divided by the three-dimensional space where the corresponding component unit is located is reduced, so that the component model is reconstructed based on the reduced cell.

Optionally, the verifying whether each component model meets the preset precision requirement includes:

for any component model:

determining an impedance curve between two points which are farthest from each other on an original assembly unit and correspond to the assembly model and in a preset frequency spectrum range, and taking the impedance curve as a first curve;

determining an impedance curve between two points farthest from the component model in the preset frequency spectrum range as a second curve;

calculating the correlation coefficient of the first curve and the second curve;

if the correlation coefficient of the first curve and the second curve is larger than or equal to a preset correlation coefficient threshold value, determining that the component model meets the preset precision requirement;

if the correlation coefficient of the first curve and the second curve is smaller than the correlation coefficient threshold, determining that the component model does not meet the preset precision requirement;

to obtain a verification result for each component model.

An electromagnetic compatibility modeling apparatus of an object, comprising: the system comprises a decomposition module, a component structure conversion module, a component model construction module, an electric connection model construction module and an electromagnetic compatibility simulation model construction module;

the decomposition module is used for decomposing an object to be molded into electrical connection and P assembly units, wherein any assembly unit comprises at least one assembly, and P is determined according to the structure of the object to be molded;

The assembly structure conversion module is used for converting each assembly unit from a body structure into a surface structure consisting of a surface without thickness, and the converted assembly unit is used as a target assembly unit;

the component model construction module is used for determining at least one target unit plane corresponding to each target component unit, constructing a component model of each target component unit through the at least one target unit plane corresponding to each target component unit, wherein the three-dimensional space where one target component unit is located is divided into R unit cells, the size of each unit cell is set based on the highest frequency of electromagnetic compatibility problems needing to be concerned, one target unit plane is one unit plane of Q unit planes defined on one unit cell with component fragments needing to be modeled inside, one unit plane corresponds to one component fragment, and R is a preset fixed value which is larger than 1 based on the size of the three-dimensional space where the corresponding target component unit is located and the size of each unit cell;

the electric connection model building module is used for building an equivalent circuit model of the electric connection as a model of the electric connection;

the electromagnetic compatibility simulation model construction module is used for combining the component models of all the component units and the electrically connected model, and the combined model is used as the electromagnetic compatibility simulation model of the object to be molded.

Optionally, the component model building module includes: a target unit plane determination sub-module;

the target unit plane determination submodule is used for aiming at any target assembly unit:

Optionally, the electromagnetic compatibility modeling apparatus of an object further includes: a component model verification module and a cell size adjustment module;

the component model verification module is used for verifying whether each component model meets the preset precision requirement;

the electromagnetic compatibility simulation model construction module is used for combining the component models of all the component units and the electrically connected model when the component models meet the preset precision requirement;

And the cell size adjustment module is used for reducing the size of the cells divided by the three-dimensional space where the corresponding component units are positioned when the component models which do not meet the preset precision requirements exist, so that the component model construction module reconstructs the component models based on the reduced size cells.

According to the technical scheme, the object to be modeled is split into the electrical connection and the P component units, then the component models and the electrical connection models of the component units are respectively constructed, and finally the component models and the electrical connection models of the component units are combined, so that the electromagnetic compatibility simulation model of the object to be modeled is obtained. The modeling method provided by the invention has the advantages that the modeling process is simple and efficient, the operability is strong, the structure is synchronously simplified and optimized in the process of constructing the model, excessive experience and repeated debugging of engineers are not needed, the modeling method is suitable for practical engineering application, and the unit plane and the equivalent circuit are adopted as basic elements of the model, so that the modeling method has the advantages of simple structure, high calculation efficiency, suitability for the subdivision and calculation of various mainstream electromagnetic algorithms, and better stability and adaptability, and the modeling accuracy can be ensured while the modeling efficiency is ensured.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic flow chart of an electromagnetic compatibility modeling method of an object according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of converting a metal structure with comparable dimensions in all directions from a bulk structure to a planar structure according to an embodiment of the present invention;

FIG. 3 is a schematic flow chart of determining at least one target unit plane corresponding to any target component unit in the modeling method of electromagnetic compatibility of an object according to the embodiment of the present invention;

FIG. 4 is a schematic diagram of a unit cell according to an embodiment of the present invention;

FIG. 5 is a schematic illustration of 12 cell planes defined on a cell located in xyz space provided by an embodiment of the present invention;

FIG. 6 is a schematic diagram of a uvw coordinate system instead of an xyz coordinate system provided by an embodiment of the present invention;

FIG. 7 is a schematic diagram of a repair cell plane formed between two discontinuous target cell planes in two adjacent cells according to an embodiment of the present invention;

FIGS. 8a and 8b are schematic diagrams of a cabinet structure and an electromagnetic compatibility simulation model of the cabinet structure constructed by the modeling method provided in the present disclosure;

FIG. 9 is a diagram comparing the simulation results of the erasure modeling with the simulation results of modeling in the CAD preprocessing software according to the embodiment of the present invention;

FIG. 10 is a schematic structural diagram of an electromagnetic compatibility modeling apparatus for an object according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of an electromagnetic compatibility modeling apparatus of an object according to an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the prior art, the method for modeling the object to be modeled by electromagnetic compatibility comprises the following steps: and deleting, simplifying and the like the CAD digital model of the object to be simulated in preprocessing software such as ANSA, hyperMesh and the like, and then meshing to generate a structural model.

The inventor finds that in the process of realizing the invention, the scheme in the prior art has some problems, and the problems are specifically shown in the following steps:

ANSA, hyperMesh and other preprocessing software are generally designed for mechanical analysis of fluid, collision and the like, technical requirements of an electromagnetic compatibility simulation model are not considered, the implementation process depends on experience and repeated debugging of engineers, and a reasonable mechanism is lacked to evaluate the applicability of the model for electromagnetic compatibility simulation, so that the accuracy of the model for electromagnetic compatibility simulation is not guaranteed, and a great deal of time is consumed for implementation, which is unfavorable for engineering practical application. In addition, the model generated by the method has poor adaptability, and the model obtained by the deletion and repair is only suitable for one or more solving algorithms, but different algorithms are generally needed to analyze various electromagnetic compatibility problems in engineering development, so the application range of the modeling method is limited.

In view of the above problems, the inventors have conducted intensive studies and finally have proposed a solution, and next, an electromagnetic compatibility modeling method of an object provided by the present invention is described by way of the following examples.

Referring to fig. 1, a flow chart of an electromagnetic compatibility modeling method of an object according to an embodiment of the present invention is shown, where the method may include:

Step S101: the object to be molded is decomposed into electrical connections and P component units.

Wherein P is determined according to the structure of the object to be modeled, and one component unit comprises at least one component of the object to be modeled.

The object to be molded may be an electrically large-sized structure, and it should be noted that the electrical size is defined based on a relationship between the object and a wavelength corresponding to the highest frequency of interest, and if the size of the object is within one wavelength, the object may be considered as an electrically small size, and if the size of the object is greater than several wavelengths, the object may be considered as an electrically large size. Illustratively, the highest frequency of interest for electromagnetic compatibility is typically 1-3 GHz, which corresponds to a wavelength of 30-10 cm, then the cell phone is electrically small in size, while the car, motor car are electrically large in size.

The object to be modeled, such as an electrical large-size structure, typically includes a plurality of components, and the present embodiment decomposes the object to be modeled into P component units, and models the P component units separately.

In one possible implementation manner, the object to be modeled can be split into P components, each component is a component unit, and considering that the object to be modeled comprises more components, if modeling is performed on each component respectively, the complexity of the modeling process tends to be increased, and the modeling efficiency is reduced. That is, after the decomposition is completed, some of the component units may include one component, and some of the component units may include a plurality of components.

Considering that the size of the component units is relatively large and the size of the electrical connections existing between the component units is small, in view of the difference in size, in order to be able to accurately model the component units and the electrical connections, the present embodiment models the component units and the electrical connections in different manners, based on which the present step requires decomposing the object to be modeled into P component units and the electrical connections.

Step S102: each assembly unit is converted from a bulk structure into a planar structure consisting of a surface without thickness, and the converted assembly is used as a target assembly unit.

For a metal structure, in a radio frequency range of electromagnetic compatibility concern, because the skin effect is achieved, current is only distributed on a metal surface layer, and therefore, the thickness-free surface is used for representing the metal structure in an object to be modeled, so that the complexity of modeling can be greatly reduced, and the modeling efficiency is improved.

For thin metal structures of a wide dimension such as a car body, a cabinet, a shell and the like with a thickness of far less than Yu Chang, the center plane or the inner surface of the structure is taken as a reference, and the thin metal structures are converted into a non-thickness surface; for a metal structure such as a column, a beam, etc. with a corresponding dimension in each direction, the metal structure is converted into a closed surface formed by a non-thickness surface based on the outer surface of the structure, and referring to fig. 2, a schematic diagram of converting the metal structure with a corresponding dimension in each direction from a bulk structure into a surface structure is shown. The non-metal medium is converted into a closed surface formed by a non-thickness surface based on the outer surface of the structure, the closed surface is subjected to subsequent treatment, and the inside of the closed surface is filled with the medium after the modeling is completed.

Step S103: and determining at least one target unit plane corresponding to each target component unit, and constructing a component model of each target component unit through the at least one target unit plane corresponding to each target component unit.

The three-dimensional space where one target component unit is located is divided into R cells, the target component unit is located in the R cells obtained by dividing, one target unit plane is one unit plane of Q unit planes defined on one cell in which component segments to be modeled exist, one unit plane corresponds to one component segment, the component segment corresponding to one unit plane is used as a model of the component segment, wherein R is determined based on the size of the three-dimensional space where the corresponding target component unit is located and the size of the cell, and Q is a preset fixed value which is greater than 1.

Determining at least one target unit plane corresponding to each target component unit, and constructing a component model of each target component unit through the at least one target unit plane corresponding to each target component unit, see detailed description of the embodiments that follow.

Step S104: and constructing an equivalent circuit model of the electrical connection as a model of the electrical connection.

In this embodiment, for the electrical connection obtained by decomposition in step S101, an equivalent circuit model between connection ports of the component is established, and connection impedance of the electrical connection is represented. The electrical connection is generally much smaller than the size of the assembly unit, the grid number of the system-level model can be obviously increased by using the three-dimensional structure modeling, the local grid density required by the electrical connection is greatly different from the system-level grid density, the instability of numerical calculation can be caused, and the main influence of the electrical connection on electromagnetic compatibility is connection impedance, so that the embodiment adopts equivalent circuit modeling and simultaneously combines the modeling efficiency and the modeling accuracy.

There are various implementation manners of constructing the equivalent circuit model of the electrical connection, in one possible implementation manner, impedance between connection ports can be directly modeled and simulated in electromagnetic simulation software, and the obtained impedance data is used as a black box equivalent circuit model. The electrical connection is typically a small-sized structure with little computational resources and time taken up by direct simulation.

In another possible implementation manner, an RCL equivalent circuit, i.e. a resistance, a capacitance, and an inductance, can be constructed according to structural characteristics of the electrical connection and an impedance calculation formula of a typical structure, and parameters of elements on the equivalent circuit can be calculated by formulas according to structural dimensions. Typical structures that can be formulated for impedance include resistive inductance of metal strips, capacitance between metal faces, and the like.

Step S105: and combining the component models of all the component units and the models of the electrical connection, wherein the combined models are used as electromagnetic compatibility simulation models of the objects to be molded.

And integrating the electrically connected equivalent circuit as a circuit parameter into the component model, connecting the port of the equivalent circuit to the corresponding position on the component model, and filling the space surrounded by the converted surface with a dielectric material for the nonmetallic dielectric component. And the finally formed surface and circuit integrated model is used as an electromagnetic compatibility simulation model of the object to be molded.

According to the electromagnetic compatibility modeling method for the object, firstly, the object to be modeled is split into the electrical connection and the P component units, then the component models and the electrical connection models of the component units are respectively built, and finally, the component models and the electrical connection models of the component units are combined, so that the electromagnetic compatibility simulation model of the object to be modeled is obtained. The modeling method provided by the embodiment of the invention has the advantages of simple and efficient modeling process, strong operability, synchronous completion of the deletion optimization of the structure in the process of constructing the model, no need of excessive experience and repeated debugging of engineers, suitability for engineering practical application, simple structure, high calculation efficiency, suitability for the dissection and calculation of various mainstream electromagnetic algorithms and good stability and adaptability, and adopts the unit plane and the equivalent circuit as the basic elements of the model. The modeling method provided by the embodiment of the invention ensures modeling efficiency and modeling accuracy.

In another embodiment of the present invention, for "step S103" in the above embodiment: at least one target unit plane corresponding to each target component unit is determined, and a component model of each target component unit is constructed through the at least one target unit plane corresponding to each target component unit.

Referring to fig. 3, a flow chart illustrating determining Q target unit planes corresponding to any target component unit may include:

step S301: and dividing the three-dimensional space where the target assembly unit is positioned into R unit cells.

In this embodiment, the three-dimensional space in which the target component unit is located is divided into cells, which are space cells, and the target component unit is located inside the space formed by R cells.

The size of the cells determines the fineness of the built component model, that is, the size of the cells determines the accuracy of electromagnetic numerical simulation calculation of the generated model. The size of the cells is based on the highest frequency f of electromagnetic compatibility issues that need to be addressed ₀ Setting, for example, the size of the settable cell is less than λ/20, where λ=c/f ₀ λ is the wavelength corresponding to the highest frequency of the electromagnetic compatibility problem of interest, where c is the speed of light. It should be noted that, any electromagnetic wave or signal has a frequency range, for example, the moving 4G is 1880-2635 MHz, the interference generated by the direct current brush motor is typically DC-1 GHz, the interference generated by the PWM driving motor is typically tens kHz-hundreds MHz, and the highest frequency of the above mentioned electromagnetic compatibility problem concerned refers to the highest frequency of various signals or electromagnetic waves contained in the electromagnetic compatibility problem to be studied by modeling simulation.

The numerical algorithm of electromagnetic simulation adopts discrete differential or integral calculation, and the detail degree of the structure meets the resolution requirement of discrete step length, so that an accurate and effective calculation result can be obtained. Further improvement of the resolution or detail level of the structure in discrete steps is limited in improvement of accuracy of the calculation result, but resources and time required for calculation are increased. Thus, the structural characteristics that need to be considered for electromagnetic compatibility can be characterized by employing cells that meet the discrete step requirements of an electromagnetic numerical algorithm.

Step S302: for any cell, determining whether component fragments to be modeled exist in the cell, if component fragments to be modeled exist in the cell, determining target unit planes corresponding to the component fragments in the cell based on correlation between Q unit planes defined on the cell and the component fragments in the cell respectively, so as to obtain target unit planes corresponding to all the component fragments of the target component unit respectively, and taking the target unit planes as at least one target unit plane corresponding to the target component unit.

Wherein determining whether there is a component segment within the cell that needs to be modeled may include: intercepting component fragments of the target component unit inside the cell; calculating the coverage rate of projection of the component segment of the target component unit in the cell on the surface of the cell in the preset direction on the projection surface; it is determined whether the component section of the target component unit inside the cell is a component section that needs to be modeled based on the coverage rate.

Referring to fig. 4, a schematic diagram of a cell, where the cell is located in xyz space, and for example, when calculating the coverage rate of a projection of a component segment of a target component unit on a surface of the cell in a preset direction to a projection surface, the coverage rates Δx, Δy, Δz of projections of the component segment on surfaces of the cell xyz in three directions may be calculated, that is:

wherein S is _x 、S _y 、S _z Component segments within cells, respectively, in a single unitProjected area on xyz three-directional surface of cell, A _x 、A _y 、A _z The areas of the xyz three-directional surfaces of the cell, respectively.

If the maximum value of Δx, Δy and Δz is greater than a preset value 1, or Δx+Δy+Δz is greater than a preset value 2, determining that the component segment in the cell is the component segment to be modeled, that is, the model of the component segment needs to be built in the cell, otherwise, considering that the component segment to be modeled does not exist in the cell, that is, the model of the component segment does not need to be built in the cell.

And when determining that the model of the component segment needs to be built in any cell, determining the target cell plane corresponding to the component segment in the cell based on the correlation between the Q cell planes defined on the cell and the component segment in the cell.

Specifically, based on the correlation between the Q unit planes defined on the unit cell and the component segments in the unit cell, the process of determining the target unit plane corresponding to the component segment in the unit cell may include: calculating correlation coefficients of Q unit planes defined on the unit cell and component fragments in the unit cell respectively; and determining the unit plane corresponding to the maximum correlation coefficient in all the calculated correlation coefficients as the target unit plane corresponding to the component segment in the unit cell. Wherein the correlation coefficient is used to characterize the degree of correlation of the unit plane with the component segments.

For example, where the unit cell is located in xyz space, the minimum and maximum values in the X direction are X1 and X2, respectively, the minimum and maximum values in the Y direction are Y1 and Y2, respectively, the minimum and maximum values in the Z direction are Z1 and Z2, respectively, 12 unit planes may be defined on a unit cell, please refer to fig. 5, which shows a schematic view of 12 unit planes defined on a unit cell, the 12 unit planes include 6 surfaces and 6 diagonal planes, wherein the expressions of the 6 surfaces are: x=x1, x=x2, y=y1, y=y2, z=z1, z=z2, the expressions of the 6 diagonal planes are respectively:

In one possible implementation, the process of calculating the correlation coefficients of Q unit planes defined on a unit cell, such as the above 12 unit planes, with component segments in the unit cell includes:

(1) And uniformly sampling N points on the component segment, calculating the root mean square value of the minimum distance between the N points and the component plane for any unit plane, and taking the reciprocal of the root mean square value as the correlation coefficient between the unit plane and the component segment as a first correlation coefficient to obtain the first correlation coefficients of Q unit planes and the component segment in the unit cell respectively.

Specifically, the root mean square value of the minimum distance of N points to a unit plane can be calculated by:

wherein, RMSE _i Root mean square value, d, for component segment to ith cell plane distance _n Representing the minimum distance from the nth sample point to the ith cell plane.

(2) For any unit plane, replacing an xyz coordinate system with a uvw coordinate system with the unit plane being a uv plane, as shown in fig. 6, uniformly sampling N points on the component segment by using the coordinates of the uvw coordinate system, calculating variances of the N points of the component segment taking the w coordinate value as a variable, taking the reciprocal of the variances as a correlation coefficient of the component segment and the unit plane as a second correlation coefficient, and obtaining second correlation coefficients of the Q unit planes and the component segment in the unit cell respectively.

Specifically, the variance of N points of the component segment, which is a variable in terms of the w coordinate value, can be calculated by the following equation:

wherein Cov is _i Variance of N points of component segment corresponding to ith unit plane, w _n Is the w coordinate of the nth sampling point,

is the average of the w coordinates of the N sampling points.

Determining a unit plane corresponding to the maximum correlation coefficient in all the calculated correlation coefficients as a target unit plane corresponding to the component segment in the unit cell, wherein the unit plane specifically comprises the following steps: and for a cell, obtaining the largest first correlation coefficient from the Q unit planes and the first correlation coefficients of the component fragments in the cell respectively, if the difference value between the largest first correlation coefficient and other first correlation coefficients is larger than a first preset value, or the ratio of the largest first correlation coefficient and other first correlation coefficients is larger than a second preset value, determining the unit plane corresponding to the largest first correlation coefficient as a target unit plane corresponding to the component fragments in the cell, otherwise, obtaining the largest second correlation coefficient from the Q unit planes and the second correlation coefficients of the component fragments in the cell respectively, and determining the unit plane corresponding to the largest second correlation coefficient as a target unit plane corresponding to the component fragments in the cell.

After determining at least one target unit plane corresponding to each target component unit, a component model of each component may be constructed by using at least one target unit plane corresponding to each target component unit. The following procedure is performed for any target component unit to obtain a component model for each target component unit:

firstly, combining at least one target unit plane corresponding to the target assembly unit; then traversing the cells divided by the three-dimensional space where the target component unit is located, if component segments needing to be modeled exist in two adjacent cells, target unit planes corresponding to the two component segments in the two adjacent cells are discontinuous, and the target component unit passes through a common plane of the two adjacent cells, connecting target vertexes of two target unit planes on the two adjacent cells to form a repair unit plane, wherein the repair unit plane is a part of a common plane. The target vertex is a vertex located on the common plane among the vertices of the two target unit planes.

For example, referring to fig. 7, a target cell plane corresponding to one of two adjacent cells is 701, a target cell plane corresponding to the other cell is 702, the

target cell planes

701 and 702 are discontinuous, and a repair cell plane 703 is formed by connecting target vertices such as vertex A, B, C in fig. 7. The repair cell plane is also part of the component model.

Preferably, the method for modeling electromagnetic compatibility of an object provided in the foregoing embodiment may further include: after obtaining the component models of all the target component units, verifying whether all the component models meet the preset precision requirement; if each component model meets the preset precision requirement, executing the component models for combining all the components and the electrically connected model; if the component model which does not meet the preset precision requirement exists, the size of the cell divided by the three-dimensional space where the corresponding component is located is reduced, so that the component model is reconstructed based on the reduced cell.

The process of verifying whether each component model meets the preset precision requirement may include: the following procedure is performed for any of the component models to obtain a verification result for each of the component models:

Determining an impedance curve between two points which are farthest from each other on an original assembly corresponding to the assembly model and are in a preset frequency spectrum range, and taking the impedance curve as a first curve; determining an impedance curve between two points farthest from the component model in a preset frequency spectrum range as a second curve; calculating the correlation coefficient of the first curve and the second curve; if the correlation coefficient of the first curve and the second curve is larger than or equal to a preset correlation coefficient threshold value, determining that the component model meets a preset precision requirement; if the correlation coefficient of the first curve and the second curve is smaller than the correlation coefficient threshold, determining that the component model does not meet the preset precision requirement. Wherein the correlation coefficient of the correlation coefficients of the first curve and the second curve refers to the correlation coefficient in the mathematical definition. It should be noted that, the original component corresponding to the component model and the component model may be simulated by using the electromagnetic simulation tool, and two points farthest from the original component corresponding to the component model and two points farthest from the component model are determined through simulation.

It should be noted that, in this embodiment, the original structure of the component unit is adopted for simulation verification, and a large amount of time and computing resources are not required, because the computing resources and time required by the electromagnetic simulation algorithm are proportional to the square or cube of the grid number, when the grid with a large size is large, the time and resources are increased in square or cube, but the size of the decomposed component is smaller, and the occupied computing resources and time are small. Taking the moment method as an example, assuming that the calculation time required by each component is 1, the calculated time of 10 components is 10 respectively, and the combined system is 10++3=1000.

The inventor builds an electromagnetic compatibility simulation model of an electric drive cabinet on a subway by using the method, and the cabinet is about 3m in size and is an electric large-size structure with middle and low complexity. Fig. 8a shows a schematic diagram of a cabinet structure, and fig. 8b shows a schematic diagram of an electromagnetic compatibility simulation model constructed by using the modeling method provided in the present disclosure. For the same electromagnetic compatibility problem, under the same electromagnetic simulation environment, using the deletion Jian Jianmo in the CAD preprocessing software and the modeling method of the scheme for modeling, the obtained simulation result pair is shown in fig. 9, 901 in fig. 9 is the simulation result of deletion modeling in the CAD preprocessing software, 902 is the simulation result of modeling by adopting the modeling mode of the scheme, and the comparison of occupied resources and time is shown in the following table. As can be seen from fig. 9 and table 1, the modeling method of the scheme is high in efficiency.

Table 1 resources and time occupied by two modeling methods

The invention establishes and processes the model based on the technical requirement of electromagnetic compatibility simulation, solves the problem that the existing electromagnetic compatibility simulation lacks a targeted method and tool for processing the structural model, and is beneficial to promoting the application of the electromagnetic compatibility simulation in engineering; on the basis of meeting the requirement of electromagnetic numerical calculation on structural accuracy, the unit plane and the equivalent circuit are adopted as basic elements of the electromagnetic compatibility simulation model, so that the accuracy of simulation calculation is ensured, the calculation efficiency is greatly improved, the basic elements of the model are simple, and the split calculation is easier to realize under various mainstream electromagnetic numerical calculation methods, so that the stability and the adaptability of the model are better; the modeling method provided by the invention has the advantages of simple and efficient modeling process and strong operability, does not need to rely on the experience and repeated debugging of engineers too much, and is suitable for practical engineering application.

The embodiment of the invention also provides an electromagnetic compatibility modeling device of the object, which is described below, and the electromagnetic compatibility modeling device of the object described below and the electromagnetic compatibility modeling generation method of the object described above can be correspondingly referred to each other.

Referring to fig. 10, a schematic structural diagram of an electromagnetic compatibility modeling apparatus for an object according to an embodiment of the present invention is shown, and as shown in fig. 10, the apparatus may include: a decomposition module 1001, a component structure conversion module 1002, a component model construction module 1003, an electrical connection model construction module 1004, and an electromagnetic compatibility simulation model construction module 1005.

The decomposition module 1001 is configured to decompose an object to be molded into an electrical connection and P component units, where any component unit includes at least one component. Wherein P is determined according to the structure of the object to be modeled.

The component structure conversion module 1002 is configured to convert each component unit from a bulk structure into a surface structure composed of a surface without a thickness, and the converted component unit is used as a target component unit.

The component model building module 1003 is configured to determine at least one target unit plane corresponding to each target component unit, and build a component model of each target component unit through the at least one target unit plane corresponding to each target component unit, where a three-dimensional space where one target component unit is located is divided into R unit cells, a size of each unit cell is set based on a highest frequency of an electromagnetic compatibility problem to be focused, one target unit plane is one unit plane of Q unit planes defined on one unit cell in which a component segment to be modeled exists, and one unit plane corresponds to one component segment, where R is determined based on a size of the three-dimensional space where the corresponding target component unit is located and a size of each unit cell, and Q is a preset fixed value greater than 1.

The electrical connection model building module 1004 is configured to build an equivalent circuit model of the electrical connection as a model of the electrical connection.

The electromagnetic compatibility simulation model construction module 1005 is configured to combine the component models of all the component units and the electrically connected model, and the combined model is used as an electromagnetic compatibility simulation model of the object to be modeled.

The object electromagnetic compatibility modeling device provided by the embodiment of the invention comprises the steps of firstly splitting an object to be modeled into electric connection and P component units, then respectively constructing a component model and an electric connection model of each component unit, and finally combining the component model and the electric connection model of each component unit to obtain an electromagnetic compatibility simulation model of the object to be modeled. The modeling device provided by the embodiment of the invention has the advantages that the modeling process is simple and efficient, the operability is strong, the structure deletion optimization is synchronously completed in the process of constructing the model, the experience and repeated debugging of an engineer are not needed to be relied on, the modeling device is suitable for engineering practical application, and the unit plane and the equivalent circuit are adopted as basic elements of the model, so that the modeling device has the advantages of simple structure, high calculation efficiency, suitability for the subdivision and calculation of various mainstream electromagnetic algorithms, and good stability and adaptability. The modeling device provided by the embodiment of the invention can ensure modeling accuracy while ensuring modeling efficiency.

In one possible implementation manner, in the electromagnetic compatibility modeling apparatus for an object provided in the foregoing embodiment, the component model building module 1003 includes: the target cell plane determines the sub-module.

A target unit plane determination sub-module for, for any target component unit:

to obtain at least one target unit plane corresponding to each target component unit.

The target unit plane determining submodule is specifically used for intercepting the component fragments of the target component unit in the cell when determining whether the component fragments needing to be modeled exist in the cell; calculating the coverage rate of projection of the component segment of the target component unit in the cell on the surface of the cell in the preset direction on the projection surface; it is determined whether the component section of the target component unit inside the cell is a component section that needs to be modeled based on the coverage rate.

In one possible implementation manner, the target unit plane determining submodule is specifically configured to calculate correlation coefficients of Q unit planes defined on the unit cell with component segments in the unit cell when determining the target unit plane corresponding to the component segments in the unit cell based on correlations of the Q unit planes defined on the unit cell with the component segments in the unit cell, respectively; and determining the unit plane corresponding to the maximum correlation coefficient in all the calculated correlation coefficients as the target unit plane corresponding to the component segment in the unit cell. Wherein the correlation coefficient is used to characterize the degree of correlation of the unit plane with the component segments.

In one possible implementation manner, in the electromagnetic compatibility modeling apparatus of the above object, the component model building module 1003 includes: the component model determines the sub-modules.

Component model determination submodule for, for any target component unit:

combining at least one target unit plane corresponding to the target assembly unit; traversing the cells divided by the three-dimensional space where the target component unit is located, and if component fragments needing to be modeled exist in two adjacent cells, and target unit planes corresponding to the two component fragments in the two adjacent cells are discontinuous, and the target component unit passes through a common plane of the two adjacent cells, connecting target vertexes of two target unit planes on the two adjacent cells to form a repair unit plane, wherein the target vertexes are vertexes positioned on the common plane;

To obtain a component model for each target component unit.

Preferably, the electromagnetic compatibility modeling apparatus for an object provided in the above embodiment may further include: a component model verification module and a cell size adjustment module.

And the component model verification module is used for verifying whether each component model meets the preset precision requirement.

And the electromagnetic compatibility simulation model construction module is used for combining the component models of all the component units and the electrically connected models when all the component models meet the preset precision requirement.

And the cell size adjustment module is used for reducing the size of the cells divided by the three-dimensional space where the corresponding component units are positioned when the component model which does not meet the preset precision requirement exists, so that the component model construction module reconstructs the component model based on the cells with reduced size.

In one possible implementation, the component model verification module is specifically configured to, for any component model:

determining an impedance curve between two points which are farthest from each other on an original assembly unit and correspond to the assembly model and in a preset frequency spectrum range, and taking the impedance curve as a first curve; determining an impedance curve between two points farthest from the component model in a preset frequency spectrum range as a second curve; calculating the correlation coefficient of the first curve and the second curve; if the correlation coefficient of the first curve and the second curve is larger than or equal to a preset correlation coefficient threshold value, determining that the component model meets a preset precision requirement; if the correlation coefficient of the first curve and the second curve is smaller than the correlation coefficient threshold, determining that the component model does not meet the preset precision requirement;

To obtain a verification result for each component model.

The embodiment of the invention also provides an electromagnetic compatibility modeling device of an object, referring to fig. 11, a schematic structural diagram of the electromagnetic compatibility modeling device of the object is shown, where the device may include: at least one processor 1101, at least one communication interface 1102, at least one memory 1103 and at least one communication bus 1104;

in the embodiment of the present invention, the number of the processor 1101, the communication interface 1102, the memory 1103 and the communication bus 1104 is at least one, and the processor 1101, the communication interface 1102 and the memory 1103 complete communication with each other through the communication bus 1104;

the processor 1101 may be a central processing unit CPU, or a specific integrated circuit ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement embodiments of the present invention, etc.;

the memory 1103 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), etc., such as at least one magnetic disk memory;

wherein the memory stores a program, and the processor is operable to invoke the program stored in the memory, the program being operable to:

and combining the component models of all the component units and the models of the electrical connection, wherein the combined models are used as electromagnetic compatibility simulation models of the objects to be molded.

Alternatively, the refinement function and the extension function of the program may be described with reference to the above.

The embodiment of the present invention also provides a readable storage medium storing a program adapted to be executed by a processor, the program being configured to:

Finally, it is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of modeling electromagnetic compatibility of an object, comprising:

combining the component models of all the component units and the electrically connected models, wherein the combined models are used as electromagnetic compatibility simulation models of the objects to be molded;

wherein the determining at least one target unit plane corresponding to each target component unit includes: for any target component unit: dividing a three-dimensional space in which the target assembly unit is positioned into R unit cells; for any cell, determining whether component fragments needing to be modeled exist in the cell, if the component fragments needing to be modeled exist in the cell, determining target unit planes corresponding to the component fragments in the cell based on the correlation between Q unit planes defined on the cell and the component fragments in the cell respectively, so as to obtain target unit planes corresponding to all the component fragments of the target component unit respectively, and taking the target unit planes as at least one target unit plane corresponding to the target component unit; to obtain at least one target unit plane corresponding to each target assembly unit.

2. The method of modeling electromagnetic compatibility of an object according to claim 1, wherein determining whether there is a component segment within the cell that needs to be modeled comprises:

intercepting component fragments of the target component unit inside the cell;

3. The method for modeling electromagnetic compatibility of an object according to claim 1, wherein determining the target unit plane corresponding to the component segment in the cell based on the correlation between the Q unit planes defined on the cell and the component segment in the cell, respectively, comprises:

4. The method for modeling electromagnetic compatibility of an object according to claim 1, wherein said constructing a component model of each target component unit by at least one target unit plane corresponding to each target component unit comprises:

for any target component unit:

to obtain a component model for each of the target component units.

5. The modeling method of electromagnetic compatibility of any one of claims 1 to 4, further comprising:

6. The method of modeling electromagnetic compatibility according to claim 5, wherein verifying whether each component model meets a preset accuracy requirement comprises:

for any component model:

to obtain a verification result for each component model.

7. An electromagnetic compatibility modeling apparatus for an object, comprising: the system comprises a decomposition module, a component structure conversion module, a component model construction module, an electric connection model construction module and an electromagnetic compatibility simulation model construction module;

the electromagnetic compatibility simulation model construction module is used for combining the component models of all the component units and the electrically connected model, and the combined model is used as the electromagnetic compatibility simulation model of the object to be molded;

wherein, the component model construction module comprises: a target unit plane determination sub-module; the target unit plane determination submodule is used for aiming at any target assembly unit: dividing a three-dimensional space in which the target assembly unit is positioned into R unit cells; for any cell, determining whether component fragments needing to be modeled exist in the cell, if the component fragments needing to be modeled exist in the cell, determining target unit planes corresponding to the component fragments in the cell based on the correlation between Q unit planes defined on the cell and the component fragments in the cell respectively, so as to obtain target unit planes corresponding to all the component fragments of the target component unit respectively, and taking the target unit planes as at least one target unit plane corresponding to the target component unit; to obtain at least one target unit plane corresponding to each target assembly unit.

8. The electromagnetic compatibility modeling apparatus of claim 7, further comprising: a component model verification module and a cell size adjustment module;