CN117875131A - Mixed simplified modeling method based on time domain bouncing ray method and transmission line equation - Google Patents
Mixed simplified modeling method based on time domain bouncing ray method and transmission line equation Download PDFInfo
- Publication number
- CN117875131A CN117875131A CN202410140686.8A CN202410140686A CN117875131A CN 117875131 A CN117875131 A CN 117875131A CN 202410140686 A CN202410140686 A CN 202410140686A CN 117875131 A CN117875131 A CN 117875131A
- Authority
- CN
- China
- Prior art keywords
- transmission line
- ray
- target
- incident
- bouncing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000005540 biological transmission Effects 0.000 title claims abstract description 81
- 238000000034 method Methods 0.000 title claims abstract description 66
- 238000004422 calculation algorithm Methods 0.000 claims abstract description 3
- 230000005684 electric field Effects 0.000 claims description 26
- 239000013598 vector Substances 0.000 claims description 14
- 238000004364 calculation method Methods 0.000 claims description 13
- 230000008569 process Effects 0.000 claims description 9
- 230000009466 transformation Effects 0.000 claims description 7
- 230000005672 electromagnetic field Effects 0.000 claims description 6
- 239000011159 matrix material Substances 0.000 claims description 4
- 230000008859 change Effects 0.000 claims description 2
- 230000003287 optical effect Effects 0.000 claims description 2
- 230000000644 propagated effect Effects 0.000 claims description 2
- 230000005855 radiation Effects 0.000 claims description 2
- 238000010168 coupling process Methods 0.000 abstract description 12
- 230000008878 coupling Effects 0.000 abstract description 11
- 238000005859 coupling reaction Methods 0.000 abstract description 11
- 238000004458 analytical method Methods 0.000 abstract description 8
- 238000010586 diagram Methods 0.000 description 8
- 238000004088 simulation Methods 0.000 description 5
- 238000001514 detection method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000005670 electromagnetic radiation Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005191 phase separation Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
- G06F30/23—Design optimisation, verification or simulation using finite element methods [FEM] or finite difference methods [FDM]
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
- G06T17/00—Three dimensional [3D] modelling, e.g. data description of 3D objects
- G06T17/20—Finite element generation, e.g. wire-frame surface description, tesselation
- G06T17/205—Re-meshing
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Geometry (AREA)
- General Physics & Mathematics (AREA)
- Computer Graphics (AREA)
- Software Systems (AREA)
- Computer Hardware Design (AREA)
- Evolutionary Computation (AREA)
- General Engineering & Computer Science (AREA)
- Measurement Of Radiation (AREA)
Abstract
The invention discloses a mixed simplified modeling method based on a time domain bouncing ray method and a transmission line equation, which comprises the following steps: firstly, reading triangular surface metadata in a target body grid file, and creating a virtual incident surface according to the target triangular surface metadata; secondly, generating a ray tube by a virtual incidence plane, detecting the intersection with a target triangular surface element and tracking the ray field intensity; then calculating the field intensity of the time domain near field of the target according to the time domain bouncing ray algorithm to obtain the field distribution at the position of the transmission line; and finally substituting the field intensity at the position of the transmission line into a transmission line equation, and calculating to obtain the voltage value and the current value of the position of the port of the transmission line. The invention solves the limitation of slow operation speed of the existing electric large-size structure for calculating the field-line coupling, and finally realizes the rapid analysis of the electric large-size structure for the field-line coupling.
Description
Technical Field
The invention belongs to the technical field of electromagnetic pulse effect analysis, and particularly relates to a mixed simplified modeling method based on a time domain bouncing ray method and a transmission line equation.
Background
With the development of wireless communication technology and electromagnetic pulse technology, the surrounding electromagnetic environment becomes more and more complex. The electromagnetic environment comprises natural interference sources such as thunder and lightning, static electricity and the like, and strong artificial interference sources such as high-power radars, electronic interference equipment, strong electromagnetic radiation interference machines and the like. In the complex electromagnetic environment, electronic devices, especially sensitive circuits and bare transmission line structures in the radio frequency microwave system are easily interfered by external electromagnetic pulses. Under the influence of electromagnetic pulses, the cable transmission lines can serve as containers for collecting a large amount of electromagnetic energy, and the electromagnetic energy can be transmitted through metal wires to influence various electronic and electrical equipment. This effect may simply cause electromagnetic interference to the device, but in extreme cases may lead to damage or even burn-out of the electronic device. In the past, when analyzing a field-line coupling structure, especially when analyzing an electrically large-sized structure, a numerical calculation method such as a Finite-Difference Time-Domain (finish), problems of low efficiency and long calculation Time are often revealed. Therefore, in order to overcome the shortcomings of the existing methods for analyzing field-line coupling structures, a general and rapid analysis method is needed.
Disclosure of Invention
The invention aims to provide a hybrid simple modeling method based on a time domain bouncing ray method and a transmission line equation, which solves the problem that the operation speed of the existing electric large-size structure for calculating field-line coupling is slow, and realizes the rapid analysis of the electric large-size structure for field-line coupling.
The technical solution for realizing the purpose of the invention is as follows: a mixed simplified modeling method based on a time domain bouncing ray method and a transmission line equation is used for carrying out quick electromagnetic analysis on a field-line coupling structure target, and comprises the following steps:
step 1, reading triangular surface metadata in a target body grid file, and creating a virtual incident surface according to the target triangular surface metadata;
step 2, generating a ray tube from the virtual incidence surface, performing intersection detection with the target triangular surface element, and if the ray tube intersects with the target triangular surface element, enabling the ray tube to be effective;
step 3, carrying out field intensity tracking on the effective ray tube, and carrying out calculation on the field intensity of the near field of the time domain on the target according to the time domain bouncing ray method to obtain field distribution at the position of the transmission line;
and 4, substituting the field intensity at the position of the transmission line into a transmission line equation, and calculating to obtain a voltage value and a current value of the position of the port of the transmission line.
Further, the step 1 specifically includes: let the number of the read triangle surface element vertexes be N, and the three-dimensional coordinates of the triangle surface element vertexes be Q (x, y, z), according toCalculating two-dimensional vertex coordinates +.>And F is a coordinate transformation matrix, traversing N triangular surface element vertexes, and projecting the vertexes onto a virtual incidence plane to obtain all two-dimensional vertexes forming the virtual incidence plane.
11. The hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation according to claim 2, wherein the coordinate transformation matrix F is:
wherein θ andthe incidence angle of electromagnetic waves is represented, theta is the included angle between the incidence direction and the positive direction of the Z axis, and the value range is 0-pi; />The included angle between the projection of the incident direction in the XOY plane and the forward direction of the X axis is 0-2 pi.
Further, in the step 2, the generating the tube from the virtual incident surface specifically includes: the dividing step length of the ray tube is determined according to the wavelength lambda of the incident electromagnetic field, the virtual incident surface is subdivided into a plurality of triangular grids based on the dividing step length, and for each triangular grid, three vertexes of the grid form a group of ray tubes which are respectively used as starting points of three incident rays in the corresponding ray tube.
Further, the detecting the intersection with the target triangle in the step 2 specifically includes: and calculating the intersection point of the ray tube and the target triangular surface element through the equation of the straight line propagated by the simultaneous ray tube and the equation of the plane of the target triangular surface element, and if the intersection point is positioned in the target triangular surface element, the ray tube is effective.
Further, the linear equation of the ray tube propagation is:
in the method, in the process of the invention,for the starting point of ray propagation, +.>The parameter t represents the distance between the origin of the ray and the intersection point, which is the propagation direction of the ray;
assuming that the position vectors of three vertexes of a triangular surface element of the target areAndthe plane equation in which the triangular surface element is located is:
wherein,representation threeNormal vector of plane of angle, +.>Representing a position vector at any point on the plane.
Further, the intersection point of the ray tube and the target triangle is:
further, the step 3 specifically includes:
at the ith intersection point of the passing ray with the targetIs the i+1th intersection point of the ray with the object>The field intensity at the point is:
wherein,e is the distance moved by the ray from the reflection point of the ith reflection to the reflection point of the (i+1) th reflection -jkd Is caused by a change of phase during propagation, < >>Is the ith reflection point->Reflection coefficient at->Is the ith reflection point->Reflected electric field at DF (d 0) i For radiation at the ith reflection point +.>A divergence factor at the location.
When a certain secondary ray tube is incident on or reflected from the target surface, if the tube passes through the observation point Q during the bouncing process, thenFor an incident electric field in which this time the tube intersects the target, +.>For the reflected electric field of the sub-tube intersecting the target, will +.>Is expressed as:
wherein ω represents an angular frequency,indicating the incident electric field, +.>Indicating the starting position of the tube intersecting the target surface, < >>Indicating the position of the bundle of rays as it passes the point of view, l GO Projection of the observation point Q on the central ray target surface propagation path of the optical ray tube; the time domain reflection electric field of the observation point Q is obtained through Fourier transformation:
wherein t represents time, Γ (t) represents time domain reflection coefficient, t d Indicating the total time delay of the device,representing the time domain incident electric field, s (t) representing the incident source.
Further, the transmission line equation affected by the electromagnetic field in the step 4 is:
wherein r represents a resistance per unit length, g represents a conductance per unit length, c represents a capacitance per unit length, V (z, t) represents a voltage vector on the transmission line, I (z, t) represents a current vector on the transmission line, V F (z, t) denotes an equivalent voltage source, I F (z, t) denotes an equivalent current source, E i Indicating the incident field and l the transmission line length.
Further, the voltage value and the current value of the transmission line port in the step 4 are as follows:
wherein,represents the length of the line element added at both ends of the transmission line, Δt represents the time interval, R s R represents the resistance value of the connection at the beginning of the transmission line L 、C 1 And L 1 Respectively representing the load resistance value, capacitance value and inductance value of terminal connection, < >>Line integral representing the electric field component of a normally incident transmission line,/->Representing the difference between the tangential electric field component of the tangential incident transmission line and the tangential electric field component of the surface of the shielded room,/->Representing the current value, V n+1 Representing the voltage value, V 1 n+1 、/>And->Boundary conditions of voltage and current respectively representing the start and end of the transmission line, R, C and L respectively represent resistance, capacitance and inductance of the transmission line connection
Compared with the prior art, the invention has the beneficial effects that: (1) The invention adopts the method of generating the ray tube by the virtual incidence surface, and only needs to fit a small amount of subdivision triangle surface metadata of the appearance of the target surface, thereby reducing the requirement of storing the triangle surface metadata and reducing the use of the memory; (2) According to the invention, the time domain bouncing ray method and the transmission line equation method are mixed to solve the electric large-size target time domain near field intensity, and compared with an accurate full-wave analysis method, the transmission line fine structure and free space are not required to be discretized, so that the calculation time is greatly reduced, and the calculation efficiency is improved.
Drawings
FIG. 1 is a flow chart of a hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation in the present invention.
Fig. 2 (a) is a schematic diagram of a target ontology model in the present invention, and fig. 2 (b) is a schematic diagram of a triangle surface subdivision of the target ontology in the present invention.
FIG. 3 is a schematic representation of ray-triangle intersection in accordance with the present invention.
FIG. 4 is a schematic diagram of the first incidence of rays and corresponding pentahedron in the present invention.
FIG. 5 is a schematic diagram of ray-continuous reflection and corresponding pentahedron in the present invention.
FIG. 6 is a schematic diagram of the ray-exit and corresponding pentahedron of the present invention.
Fig. 7 is a schematic diagram of a simulation of the field-line coupling process in accordance with the present invention.
Fig. 8 (a) and 8 (b) are schematic diagrams showing the comparison between the voltage values of the left and right ports of the transmission line generated by the method of the present invention and the voltage values of the left and right ports generated by simulation using CST software, respectively.
Fig. 9 (a) and 9 (b) are schematic diagrams showing comparison between the current values of the left and right ports of the transmission line generated by the method of the present invention and the current values of the left and right ports generated by simulation using CST software, respectively.
Detailed Description
The invention is described in further detail below with reference to the drawings and the specific embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. The methods and means used in the description of the specific embodiments of the present invention are for completely and clearly explaining the present invention and are not limited thereto.
Referring to fig. 1, the hybrid reduced modeling method based on the time domain bouncing ray method and the transmission line equation of the invention comprises the following steps:
step 1, reading triangular surface metadata in a target body grid file, and creating a virtual incident surface according to the target triangular surface metadata, wherein the method specifically comprises the following steps of:
with reference to fig. 2, triangle face subdivision is first modeled in commercial software. And secondly, the triangular surface element data in the triangular mesh file is read, wherein the triangular surface element data comprises the number M of triangular surface elements, the number N of triangular surface element vertexes and triangular surface element vertex coordinates. Finally, with reference to fig. 3, a virtual incident plane is created according to the read target triangle metadata, specifically as follows:
for example, the vertex coordinate of a certain triangular surface element is Q (-0.1,0.5,0.0), and the coordinate transformation formula is:
the two-dimensional vertex coordinates Q' (-0.27884, -0.42426) on the virtual incidence plane can be calculated, and similarly, the two-dimensional vertex coordinates of the three-dimensional vertex coordinates Q (x, y, z) of all the triangular surface elements on the virtual incidence plane can be sequentially calculated according to the modeThen respectively finding all two-dimensional coordinate points in y θ And->Maximum and minimum values of direction so that y can be used θmax 、y θmin 、/>The boundary of the virtual incidence plane is defined to form a rectangular area.
Step 2, generating a ray tube from the virtual incidence surface, and detecting the intersection with the target triangle surface element, wherein the method specifically comprises the following steps:
the division step size of the tube is determined on the basis of the wavelength lambda of the incident electromagnetic field, and it is generally required that the spacing between the tubes does not exceed one tenth of a wavelength in order to achieve a desired accuracy. Thus, when λ/10 is taken as the spacing between the dividing rays, the virtual entrance face may be subdivided into several triangular meshes. For each triangular mesh, three vertices of the mesh form a set of ray tubes, which serve as starting points for three incident rays in the corresponding ray tube, respectively, for subsequent ray intersection detection with the bin, and the center of the mesh is used for recording field intensity information and phase information of the ray tube.
In connection with fig. 3, in performing intersection detection of a ray with a target triangle, a straight-line path traveled by the ray may be represented by the following straight-line equation:
in the method, in the process of the invention,for the starting point of ray propagation, +.>The parameter t represents the distance of the origin of the ray from the intersection point, which is the direction of propagation of the ray. Assume that the position vector of three vertices of a planar triangle surface element is +.>Andthe plane in which the triangle bin lies may represent:
is obtainable by the combination of (9) and (10):
thus, the intersection of the ray and the triangle primitive is:
step 3, carrying out field intensity tracking on the effective rays, and carrying out calculation on the time domain near field intensity on the target according to a time domain bouncing ray algorithm to obtain field distribution at the position of the transmission line:
in the case of rays intersecting a target, the field strength of the reflected ray is determined by both the field strength of the incident ray and the reflection coefficient of the target surface. Thus, the ith intersection point of the passable ray and the targetDeriving the i+1th intersection point with the target +.>Field strength at the location.
In order to calculate the field strength at a certain point Q of the transmission line position, it has to be determined whether the tube has passed this point during propagation. The problem occurs in three different scenes, wherein each scene involves judging the relative position relation between an observation point and a pentahedron in space, and the three scenes are as follows:
(1) Referring first to fig. 4, the first intersection of a ray with a target is a process in which an initial ray tube on a virtual incidence plane intersects a path of a reflection of the intersection of the target triangle. The coordinates of three corner rays defined by a beam of ray tube on a virtual incidence plane are respectively marked as v 1 、v 2 V 3 . When the beam tube intersects the target triangle, the corresponding initial intersection coordinates are denoted as u 1 、u 2 And u 3 The geometry formed by these six points forms a pentahedron. Thus, the problem of whether the beam tube propagates past the point Q at this time can be regarded as a problem of the positional relationship between the point Q and the pentahedron in space.
(2) Second knotTurning to fig. 5, the process of rays from the n-1 th reflecting surface to the n-th reflecting surface is shown. When the n-1 th reflection is set, the intersecting positions of the three corner rays and the subdivision surface element of one beam of ray tube are respectively marked as v 1 、v 2 V 3 And in the nth reflection, the intersecting positions of the three corner rays and the surface element of the ray tube are respectively marked as u 1 、u 2 And u 3 . These six points constitute a pentahedron, and thus, the problem of whether the beam tube propagates through the observation point Q at this time can be regarded as a problem of the positional relationship between the observation point Q and the pentahedron in space.
(3) Finally, in connection with fig. 6, the process of the last reflection of the ray is described. The intersection positions of three corner rays of a certain beam tube and the triangular surface element on the last reflecting surface are respectively marked as v 1 、v 2 V 3 . According to(/>Representing the direction of ray exit, m is a sufficiently large number to ensure accuracy of calculation) can yield three vertices u of a virtual exit plane 1 、u 2 And u 3 The geometry formed by these six points forms a pentahedron. Thus, the problem of whether the beam tube propagates through the observation point Q at this time can be regarded as a problem of the positional relationship between the observation point Q and the pentahedron in space.
In view of the above three cases, in each process of field intensity tracking, it is necessary to determine the positional relationship between the pentahedron generated by each beam tube in the propagation stage and the observation point one by one. If the point Q is in the pentahedron, phase information can be obtained by projection of the point Q onto the central ray path and the overall electric field of the point Q can be found by accumulating field strength vectors.
When a certain secondary tube is incident on or reflected from the target surface, if the tube passes through the point Q during the bouncing process, it can be provided thatFor an incident electric field in which this time the tube intersects the target, +.>For the reflected electric field of the sub-tube intersecting the target, will +.>The phase separation of (a) can be expressed as:
the time-domain incident electric field and the time-domain reflected electric field of the observation point Q, which can be obtained by fourier transform, can be expressed as:
wherein,is the total time delay.
According to the steps, the calculation of the time domain near field intensity can be carried out on the target, and the field distribution at the position of the transmission line can be obtained.
Step 4, substituting the field intensity at the position of the transmission line into a transmission line equation, and calculating to obtain a voltage value and a current value of the position of the port of the transmission line, wherein the voltage value and the current value are specifically as follows:
in connection with fig. 7, the transmission line equation for electromagnetic field effects is expressed as:
wherein r represents a resistance per unit length, g represents a conductance per unit length, c represents a capacitance per unit length, V (z, t) represents a voltage vector on the transmission line, I (z, t) represents a current vector on the transmission line, V F (z, t) denotes an equivalent voltage source, I F (z, t) denotes an equivalent current source, E i Indicating the incident field and l the transmission line length.
Substituting the field intensity at the transmission line position obtained in the step 3 into formulas (12) to (15) to obtain a voltage value and a current value of the transmission line port position:
wherein,represents the length of the line element added at both ends of the transmission line, Δt represents the time interval, R s R represents the resistance value of the connection at the beginning of the transmission line L 、C 1 And L 1 Respectively representing the load resistance value, capacitance value and inductance value of terminal connection, < >>Line representing electric field component of normal incidence transmission lineIntegration (I)>Representing the difference between the tangential electric field component of the tangential incident transmission line and the tangential electric field component of the surface of the shielded room,/->Representing the current value, V n+1 Representing the voltage value, V 1 n+1 、/>And->Boundary conditions of voltage and current at the start and end of the transmission line are shown, and R, C and L represent resistance, capacitance and inductance of the transmission line connection, respectively.
The simulation calculation is carried out on the field-line coupling structure shown in fig. 2 (a) and 2 (b) according to the method of the invention, and the geometric dimensions of the model are as follows: transmission line length d=1m, height h=2cm, radius r=2mm. The shielding case has a pure metal structure, and the length is 20cm, the width is 20cm and the height is 10cm. One end of the transmission line is connected with a load resistor R 1 =150Ω, the other end extends into the metal shielding box and is connected with a group of parallel impedance element circuits including a load resistor R 2 =100Ω, capacitance c=20pf, and inductance l=5μh. In addition, the position of the excitation source is set by adopting the central frequency f 0 Gaussian pulse wave of =6ghz as incident source, the main parameter is E 0 ＝1000V/m，τ＝2ns，t 0 =0.8τ. The pulse incidence direction is along θ=45°,and vertically polarizing. Fig. 8 (a), 8 (b), 9 (a) and 9 (b) are compared with the calculation result of the field-line coupling structure rapid analysis method based on the time domain bouncing ray and the transmission line equation and the simulation result of the CST software, so that the result of the method and the result of the CST software are basically consistent, and the accuracy of the method is proved. In combination with Table 1, it can be seen that the present inventionThe clear method has the advantage of calculating time compared with CST software.
TABLE 1 calculation time comparison of the inventive method with CST software
Table 1 calculation of time contrast
In summary, the hybrid simple modeling method based on the time domain bouncing ray method and the transmission line equation greatly reduces the operation time for calculating the electric large-size structure of the field-line coupling, and realizes the rapid analysis of the electric large-size structure of the field-line coupling.
The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention. The components not explicitly described in this embodiment can be implemented by using the prior art.
Claims (10)
1. A mixed simplified modeling method based on a time domain bouncing ray method and a transmission line equation is characterized by comprising the following steps:
step 1, reading triangular surface metadata in a target body grid file, and creating a virtual incident surface according to the target triangular surface metadata;
step 2, generating a ray tube from the virtual incidence surface, detecting the intersection with the target triangular surface element, if the ray tube intersects with the target triangular surface element, enabling the ray tube to be effective, and executing the step 3;
step 3, carrying out field intensity tracking on the effective ray tube, and carrying out calculation on the field intensity of the near field of the time domain on the target according to a time domain bouncing ray algorithm to obtain field distribution at the position of the transmission line;
and 4, substituting the field intensity at the position of the transmission line into a transmission line equation, and calculating to obtain a voltage value and a current value of the position of the port of the transmission line.
2. The hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation according to claim 1, wherein the step 1 specifically includes: let the number of the read triangle surface element vertexes be N, and the three-dimensional coordinates of the triangle surface element vertexes be Q (x, y, z), according toCalculating two-dimensional vertex coordinates +.>And F is a coordinate transformation matrix, traversing N triangular surface element vertexes, and projecting the vertexes onto a virtual incidence plane to obtain all two-dimensional vertexes forming the virtual incidence plane.
3. The hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation according to claim 2, wherein the coordinate transformation matrix F is:
wherein θ andthe incidence angle of electromagnetic waves is represented, theta is the included angle between the incidence direction and the positive direction of the Z axis, and the value range is 0-pi;the included angle between the projection of the incident direction in the XOY plane and the forward direction of the X axis is 0-2 pi.
4. The hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation according to claim 2, wherein the generating the ray tube from the virtual incident surface in step 2 specifically comprises: the dividing step length of the ray tube is determined according to the wavelength lambda of the incident electromagnetic field, the virtual incident surface is subdivided into a plurality of triangular grids based on the dividing step length, and for each triangular grid, three vertexes of the grid form a group of ray tubes which are respectively used as starting points of three incident rays in the corresponding ray tube.
5. The method for hybrid reduced modeling based on time-domain bouncing ray method and transmission line equation according to claim 4, wherein the detecting of intersection with the target triangle in step 2 specifically comprises: and calculating the intersection point of the ray tube and the target triangular surface element through the equation of the straight line propagated by the simultaneous ray tube and the equation of the plane of the target triangular surface element, and if the intersection point is positioned in the target triangular surface element, the ray tube is effective.
6. The hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation according to claim 5, wherein the linear equation of the ray tube propagation is:
wherein,representing the starting point of ray propagation, +.>Representing the propagation direction of the ray, and the parameter t represents the distance between the origin of the ray and the intersection point;
assuming that the position vectors of three vertexes of a triangular surface element of the target areAndthe plane equation in which the triangular surface element is located is:
wherein,normal vector representing the plane of the triangle, +.>Representing a position vector at any point on the plane.
7. The hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation of claim 6, wherein the intersection point of the ray tube and the target triangle is:
8. the hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation according to claim 5, wherein the step 3 specifically includes:
at the ith intersection point of the passing ray with the targetIs the i+1th intersection point of the ray with the object>The field intensity at the point is:
wherein,e is the distance moved by the ray from the reflection point of the ith reflection to the reflection point of the (i+1) th reflection -jkd Is caused by a change of phase during propagation, < >>Is the ith reflection point->Reflection coefficient at->Is the ith reflection point->Reflected electric field, DF (d) i For radiation at the ith reflection point +.>A divergence factor at;
when a certain secondary ray tube is incident on or reflected from the target surface, if the tube passes through the observation point Q during the bouncing process, thenFor an incident electric field in which this time the tube intersects the target, +.>For the reflected electric field of the sub-tube intersecting the target, will +.>Is expressed as:
wherein ω represents an angular frequency,indicating the incident electric field, +.>Indicating the starting position of the tube intersecting the target surface,indicating the position of the bundle of rays as it passes the point of view, l GO Projection of the observation point Q on the central ray target surface propagation path of the optical ray tube; the time domain reflection electric field of the observation point Q is obtained through Fourier transformation:
wherein t represents time, Γ (t) represents time domain reflection coefficient, t d Indicating the total time delay of the device,representing the time domain incident electric field, s (t) representing the incident source.
9. The hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation according to claim 8, wherein the transmission line equation affected by the electromagnetic field in step 4 is:
wherein r represents a resistance per unit length, g represents a conductance per unit length, c represents a capacitance per unit length, V (z, t) represents a voltage vector on the transmission line, I (z, t) represents a current vector on the transmission line, V F (z, t) denotes an equivalent voltage source, I F (z, t) denotes an equivalent current source, E i Indicating the incident field and l the transmission line length.
10. The hybrid reduced modeling method based on time-domain bouncing ray method and transmission line equation according to claim 9, wherein the voltage value and the current value of the transmission line port position in step 4 are:
wherein,represents the length of the line element added at both ends of the transmission line, Δt represents the time interval, R s R represents the resistance value of the connection at the beginning of the transmission line L 、C 1 And L 1 Respectively representing the load resistance value, capacitance value and inductance value of terminal connection, < >>Line integral representing the electric field component of a normally incident transmission line,/->Representing the difference between the tangential electric field component of the tangential incident transmission line and the tangential electric field component of the surface of the shielded room,/->Representing the current value, V n+1 Representing the voltage value, V 1 n+1 、/>And->Boundary conditions of voltage and current at the start and end of the transmission line are shown, and R, C and L represent resistance, capacitance and inductance of the transmission line connection, respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410140686.8A CN117875131B (en) | 2024-01-31 | 2024-01-31 | Mixed simplified modeling method based on time domain bouncing ray method and transmission line equation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410140686.8A CN117875131B (en) | 2024-01-31 | 2024-01-31 | Mixed simplified modeling method based on time domain bouncing ray method and transmission line equation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117875131A true CN117875131A (en) | 2024-04-12 |
| CN117875131B CN117875131B (en) | 2024-07-09 |
Family
ID=90581097
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410140686.8A Active CN117875131B (en) | 2024-01-31 | 2024-01-31 | Mixed simplified modeling method based on time domain bouncing ray method and transmission line equation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117875131B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4502009A (en) * | 1981-01-20 | 1985-02-26 | Societe Nationale Industrielle Aerospatiale | Apparatus adapted for single pulse electromagnetic measurements of soil conductivity and dielectric constant |
| CN111767509A (en) * | 2019-04-01 | 2020-10-13 | 南京理工大学 | Efficient time domain method for analyzing transient strong electromagnetic pulse response of unmanned aerial vehicle |
| CN113076675A (en) * | 2021-04-12 | 2021-07-06 | 中国电子科技集团公司第三十三研究所 | Electromagnetic environment effect simulation design method for air cushion landing boat |
| CN114924245A (en) * | 2022-04-13 | 2022-08-19 | 北京理工大学 | Method for directly establishing scattering center model based on geometric structure |
-
2024
- 2024-01-31 CN CN202410140686.8A patent/CN117875131B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4502009A (en) * | 1981-01-20 | 1985-02-26 | Societe Nationale Industrielle Aerospatiale | Apparatus adapted for single pulse electromagnetic measurements of soil conductivity and dielectric constant |
| CN111767509A (en) * | 2019-04-01 | 2020-10-13 | 南京理工大学 | Efficient time domain method for analyzing transient strong electromagnetic pulse response of unmanned aerial vehicle |
| CN113076675A (en) * | 2021-04-12 | 2021-07-06 | 中国电子科技集团公司第三十三研究所 | Electromagnetic environment effect simulation design method for air cushion landing boat |
| CN114924245A (en) * | 2022-04-13 | 2022-08-19 | 北京理工大学 | Method for directly establishing scattering center model based on geometric structure |
Non-Patent Citations (2)
| Title |
|---|
| 丁建军;刘志伟;徐侃;娄瑜雅;陈如山;: "基于高频方法分析电大尺寸目标的散射", 系统工程与电子技术, no. 11, 15 November 2010 (2010-11-15) * |
| 李杰;郭立新;何琼;吴振森;王晓冰;: "复合电磁散射分析中的精确几何建模", 西安电子科技大学学报, no. 06, 12 September 2012 (2012-09-12) * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117875131B (en) | 2024-07-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105930567B (en) | A kind of Electromagnetic Scattering Characteristics acquisition methods based on subregion Adaptive Integral | |
| CN106772301B (en) | A kind of multilayer non-parallel interfaces medium electromagnetic scattering simulation algorithm based on medium ray tracing | |
| Ferrieres et al. | Application of a hybrid finite difference/finite volume method to solve an automotive EMC problem | |
| Bouche et al. | Asymptotic and hybrid techniques for electromagnetic scattering | |
| US6051027A (en) | Efficient three dimensional extraction | |
| CN104318021A (en) | Electromagnetic simulation method for large ship target through various high-frequency electromagnetic scattering | |
| Gres et al. | Volume‐integral‐equation‐based analysis of transient electromagnetic scattering from three‐dimensional inhomogeneous dielectric objects | |
| CN104573289A (en) | Electromagnetic scattering simulation method of one-dimensional conductor rough sea surface and two-dimensional conductor target | |
| CN110274920A (en) | The method of honorable subdivision Shooting and bouncing rays analysis metal medium target transient response | |
| CN101477195B (en) | Method for acquiring radar cross section | |
| CN117875131B (en) | Mixed simplified modeling method based on time domain bouncing ray method and transmission line equation | |
| Noda et al. | Error in propagation velocity due to staircase approximation of an inclined thin wire in FDTD surge simulation | |
| JP3703812B2 (en) | Electromagnetic field analysis method using FDTD method, medium expression method in electromagnetic field analysis, simulation apparatus, and program | |
| CN104008217A (en) | Large-scale complicated target model oriented electromagnetic wave shadow processing method | |
| Lu et al. | Multilevel plane wave time domain-based global boundary kernels for two-dimensional finite difference time domain simulations | |
| Steeds et al. | A comparison of two conformal methods for FDTD modeling | |
| CN116106637B (en) | Finite impulse even sequence characterization method for time domain electromagnetic scattering analysis | |
| Richie et al. | EFIE-MFIE hybrid simulation using NEC: VSWR for the WISP experiment | |
| Baumann | A 3-D numerical field solver based on the finite-volume time-domain method | |
| Huan et al. | PE-TL hybrid method of solving the coupling between two-wire line and external electromagnetic pulse in large-scale environment | |
| CN114741880B (en) | Method and device for calculating electromagnetic characteristics of group targets | |
| Mohammadi et al. | Electromagnetic model for microwave components of integrated circuits | |
| Ding et al. | Analysis of electromagnetic scattering of cavities with nonuniform plasma coating | |
| Mao et al. | The Research of Standard Model's RCS Calculation and its Analytical Efficiency Based on FASTEM-STUDIO | |
| CN115081204A (en) | Prediction method for transient field of ultra-wide spectrum electromagnetic pulse time domain of ultra-large power platform |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |