A method for constructing a low-scattering target and sea surface coupling scale model

Abstract

The application discloses a low-scattering target and sea surface coupling scale model construction method, which comprises the following steps: constructing a scale model of a target according to a preset scale coefficient and a prototype of the target; constructing a scale model of a sea surface according to the preset scale coefficient and a prototype of the sea surface based on a flexible medium film; and combining the scale model of the target and the scale model of the sea surface to obtain a coupling scale model of the target and the sea surface. The application can be applied to the detection and identification of aircraft and ship targets in a sea environment, and has the advantages of thin thickness, light mass, low cost and the like, and is a complex scale stealth material product with application prospect.

Description

Technical Field

[0001] This invention relates to the field of scaled-down model testing technology, and in particular to a method for constructing a coupled scaled-down model of a low-scattering target and a sea surface. Background Technology

[0002] The detection and identification of maritime targets has always been a research hotspot in the field of target characteristics; however, the time-varying and random nature of sea surface undulations and the complexity of the composite scattering between the sea surface and the target make it difficult to obtain the composite scattering characteristics between the sea surface and the target.

[0003] Currently, methods for realizing composite scattering in marine environments typically include electromagnetic calculations and experimental testing. Electromagnetic calculations struggle to balance high accuracy with high computational speed. Experimental testing includes open-water field tests and wave pool simulations. Open-water field tests are heavily influenced by the external environment and are costly, inaccurate, and difficult to implement. Wave pool simulations face challenges such as limited space, the need for equivalent models in high sea conditions (where sea surface morphology and seawater dielectric parameters suffer from dispersion effects), and the inability to directly acquire high-precision, universal far-field data. On the other hand, methods for analyzing target characteristics in marine environments typically include simulation calculations, actual testing, and scaled-down testing. Numerical simulation calculations for various scattering sources containing non-metallic materials in large, low-scattering targets remain challenging. Full-scale actual testing also faces problems such as large target size, high preparation costs, and demanding testing site requirements. Scaled-down testing, with its short cycle and low cost, has become the primary means of efficiently acquiring the characteristics of complex, low-scattering targets.

[0004] In scale-down testing, to obtain the radar cross section (RCS) of the target prototype as accurately as possible, the scaled-down model and the target prototype need to maintain the same electrical size ratio, and more importantly, ensure that their electromagnetic scattering characteristics are identical. Since modern maritime targets extensively use non-metallic materials (such as radar-absorbing materials), traditional scale-down techniques for metallic targets are insufficient to meet the testing requirements of complex scaled-down models. Furthermore, the scaled-down construction of non-metallic materials often faces two main challenges: 1. Magnetic loss-coated stealth materials have small surface thickness and simple structures, requiring the design of scaled-down materials to address the multiple solutions to the constraints between electromagnetic parameters, thickness, and various scattering sources; 2. Structural radar-absorbing materials, due to the uneven thickness of their prototype structural samples, require solutions to the structural dimensions, electromagnetic parameters, and coupling issues between the scaled-down materials. Therefore, for low-scattering targets with various scattering mechanisms (such as multiple reflections, edge diffraction, surface creeping waves, and surface traveling waves) coupled with the marine environment, traditional scaled-down construction methods will face problems such as deviations in RCS and scattering centers. Summary of the Invention

[0005] The purpose of this invention is to provide a method for constructing a coupled scaled model of a low-scattering target and a sea surface, so that the constructed coupled scaled model of the low-scattering target and the sea surface has the characteristics of high accuracy and low cost.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] A method for constructing a coupled scaled-down model of a low-scattering target and the sea surface, comprising:

[0008] Based on the preset scaling factor and the prototype of the target, a scaled-down model of the target is constructed;

[0009] Based on a flexible dielectric thin film, a scaled-down model of the sea surface is constructed according to a prototype of the sea surface; and

[0010] The scaled-down model of the target is combined with the scaled-down model of the sea surface to obtain a coupled scaled-down model of the target and the sea surface.

[0011] Optionally, the target includes a metal component and a non-metallic component disposed on the surface of the metal component, and the step of constructing a scaled-down model of the target includes:

[0012] The prototype of the metal part is scaled down according to the preset scaling factor to construct a scaled-down model of the metal part;

[0013] Based on the preset scaling factor and the prototype material of the non-metallic component, a genetic algorithm is used to construct the scaled-down material of the non-metallic component;

[0014] A scaled-down model of the non-metallic component is prepared using a scaled-down material of the non-metallic component; and

[0015] Based on the prototype of the target, the scaled-down models of the metal parts and the non-metal parts are combined to obtain the scaled-down model of the target.

[0016] Optionally, the non-metallic component includes a honeycomb absorbing panel, and the step of constructing the scaled-down material of the non-metallic component includes:

[0017] Based on the prototype material of the honeycomb absorbing plate, the composition of the scaled-down material of the honeycomb absorbing plate is obtained; the composition of the scaled-down material of the honeycomb absorbing plate includes first absorbing microparticles and binder, and the volume ratio of the first absorbing microparticles in the scaled-down material of the honeycomb absorbing plate is a first addition ratio, and the thickness of the scaled-down material of the honeycomb absorbing plate is a first thickness.

[0018] The first addition ratio and the thickness are used as optimization variables, and a first optimization objective function is constructed based on the cumulative deviation between the reflectivity of the scaled material of the honeycomb absorbing plate and the reflectivity of the prototype material of the honeycomb absorbing plate under different incident angles of electromagnetic waves.

[0019] The genetic algorithm is used to solve the first optimization objective function to obtain the first addition ratio and the first thickness corresponding to the minimum value of the first optimization objective function, and these are taken as the optimal first addition ratio and the optimal first thickness; and

[0020] The scaled-down material of the honeycomb absorbing panel is constructed according to the optimal first addition ratio and the optimal first thickness.

[0021] Optionally, the reflectivity of the scaled-down material of the honeycomb absorbing panel is calculated using the following formula:

[0022]

[0023]

[0024]

[0025]

[0026]

[0027] Wherein, RL represents the reflectivity of the scaled-down material of the honeycomb absorbing plate; Z in The wave impedance of the scaled-down material of the honeycomb absorbing panel is represented by η0; η0 represents the vacuum wave impedance, and η0 = 377Ω; θ0 represents the incident angle of the electromagnetic wave; Z TE Z represents the wave impedance when the electromagnetic wave is in TE mode; TM The impedance represents the electromagnetic wave in TM mode; θ represents the refraction angle of the electromagnetic wave; μ r1 ε represents the permeability of the scaled-down material of the honeycomb absorbing plate. r1 The dielectric constant of the scaled-down material of the honeycomb absorbing plate is μ. r1 and ε r1 Determined by the first addition ratio; d1 represents the first thickness; c represents the speed of light in a vacuum; f s This indicates the first scaling frequency; j represents the imaginary unit, and

[0028] The first optimization objective function is expressed by the following formula:

[0029]

[0030] Wherein, F1 represents the cumulative deviation between the reflectivity of the scaled-down material of the honeycomb absorbing plate and the reflectivity of the prototype material of the honeycomb absorbing plate under different incident angles of the electromagnetic wave; n represents the total number of incident angles, n=[90° / Δθ]+1, and Δθ represents the preset interval angle, [] represents rounding; θ0 i Represents the i-th incident angle; vol represents the first addition ratio; RL(vol,d1,θ0) i ) represents the reflectivity of the prototype material of the honeycomb absorbing panel; RL0(θ0) i ) represents the reflectivity of the prototype material of the honeycomb absorbing plate.

[0031] Optionally, the non-metallic component includes a frequency-selective surface, and the step of constructing the scaled-down material of the non-metallic component includes:

[0032] Based on the prototype material of the frequency selective surface, a periodic structure of a scaled-down material of the frequency selective surface is obtained; the periodic structure of the scaled-down material of the frequency selective surface includes a scaled-down substrate medium and a scaled-down square ring disposed on the scaled-down substrate medium, and the scaled-down square ring is provided with scaled-down gaps;

[0033] The prototype material of the frequency selective surface is simulated to obtain the simulated reflection coefficient of the prototype material of the frequency selective surface.

[0034] The equivalent reflection coefficient of the scaled-down material of the frequency-selective surface is calculated according to the formula for calculating the equivalent reflection coefficient of the surface material.

[0035] The period length of the scaled square ring, the thickness of the scaled substrate medium, and the width of the scaled gap are used as optimization variables. A second optimization objective function is constructed based on the cumulative deviation between the equivalent reflection coefficient of the scaled material of the frequency-selective surface and the simulated reflection coefficient of the prototype material of the frequency-selective surface at different frequencies.

[0036] The genetic algorithm is used to solve the second optimization objective function to obtain the period length of the scaled square ring, the thickness of the scaled substrate medium, and the width of the scaled gap corresponding to the minimum value of the second optimization objective function. These are taken as the optimal period length of the scaled square ring, the optimal thickness of the scaled substrate medium, and the optimal width of the scaled gap.

[0037] The scaled material of the frequency-selective surface is constructed based on the optimal period length of the scaled square ring, the optimal thickness of the scaled substrate medium, and the optimal width of the scaled gap.

[0038] Optionally, the formula for calculating the equivalent reflection coefficient of the frequency-selective surface material is:

[0039]

[0040]

[0041]

[0042]

[0043]

[0044]

[0045]

[0046] Wherein, R represents the equivalent reflection coefficient of the frequency-selective surface material; Z inp Z represents the input impedance of the frequency-selective surface material; Z0 represents the wave impedance when incident obliquely in a vacuum, η0 is the vacuum wave impedance, and η0 = 377Ω; Z g′ Z represents the impedance of the metal mesh in the frequency-selective surface. d Let β represent the impedance of the substrate medium, d represent the propagation constant of the substrate medium, d represent the thickness of the substrate medium, μ² represent the permeability of the substrate medium, and ε represent the dielectric constant. r2 Let ω represent the dielectric constant of the substrate medium; θ0 represent the incident angle of the electromagnetic wave; θ represent the angle of refraction of the electromagnetic wave; c represent the speed of light in a vacuum; f represent the frequency; and j represent the imaginary unit. η represents the wave impedance of the substrate medium, α represents the material coefficient of the frequency-selective surface, k is the wave number in vacuum, A represents the first fitting parameter, B represents the second fitting parameter, D represents the period length of the square ring, and w represents the width of the slit.

[0047] The second optimization objective function is expressed by the following formula:

[0048]

[0049] Wherein, F2 represents the cumulative deviation between the equivalent reflection coefficient of the scaled-down material of the frequency-selective surface and the simulated reflection coefficient of the prototype material of the frequency-selective surface at different frequencies; N represents the total number of frequency points; f I Represents the i-th frequency point; R(D, w, d) represents the equivalent reflection coefficient of the scaled-down material of the frequency-selective surface; S 11 The simulated reflection coefficient represents the prototype material of the frequency-selective surface.

[0050] Optionally, the step of constructing the scaled-down model of the sea surface includes:

[0051] The scaled-down material of the sea surface is the flexible dielectric film; and the components of the flexible dielectric film include microwave absorbing particles and rubber, wherein the volume ratio of the microwave absorbing particles in the flexible dielectric film is a second addition ratio;

[0052] Calculate the reflection coefficient of the scaled-down material of the sea surface and the reflection coefficient of the original sea surface according to the formula for calculating the reflection coefficient of the sea surface.

[0053] The second addition ratio is used as the optimization variable, and a third optimization objective function is constructed based on the cumulative deviation between the reflection coefficient of the scaled-down material of the sea surface and the reflection coefficient of the prototype of the sea surface under different incident angles of electromagnetic waves.

[0054] The genetic algorithm is used to solve the third optimization objective function to obtain the second addition ratio corresponding to the minimum value of the third optimization objective function, and this ratio is taken as the optimal second addition ratio.

[0055] The flexible dielectric film is prepared according to the optimal second addition ratio;

[0056] A plurality of array points are formed on the prepared flexible dielectric film; and

[0057] Based on the shape change data of the prototype sea surface, the position of each array point is adjusted to construct a scaled-down model of the sea surface.

[0058] Optionally, the formula for calculating the reflection coefficient of the sea surface is:

[0059]

[0060] Where R′ represents the reflection coefficient of the sea surface; θ0 represents the incident angle of the electromagnetic wave; ε r3 Let be the complex relative permittivity of the sea surface;

[0061] The third optimization objective function is expressed by the following formula:

[0062]

[0063] Wherein, F3 represents the cumulative deviation between the reflection coefficient of the scaled-down material of the sea surface and the reflection coefficient of the prototype sea surface at different incident angles; θ0 represents the incident angle of the electromagnetic wave, ranging from 0 to 90°, with a step size of 1°; R′ 原型 R′ represents the reflection coefficient of the prototype of the sea surface. 缩比 R′ represents the reflection coefficient of the scaled-down material of the sea surface. 缩比 ε r3 It is determined by the second addition ratio.

[0064] Optionally, the position of each array point is adjusted using a control device, and the control device includes:

[0065] A computer for storing data on the shape changes of the sea surface prototype;

[0066] Several telescopic rods, each of which is positioned below the corresponding array point;

[0067] The motor unit is connected to the telescopic rod and is used to drive the telescopic rod to extend and retract in the vertical direction;

[0068] The servo system is connected to the computer and the motor assembly respectively, and is used to control the motor assembly to drive the telescopic rod to extend and retract based on the shape change data of the sea surface prototype, so as to adjust the position of each array point.

[0069] Optionally, the telescopic rod is made of a wave-transparent material.

[0070] Compared with the prior art, the present invention has at least one of the following advantages:

[0071] This invention provides a method for constructing a coupled scaled-down model of a low-scattering target and a sea surface. The method involves constructing a scaled-down model of the target based on a preset scaled-down coefficient and a prototype of the target; constructing a scaled-down model of the sea surface based on a flexible dielectric thin film and the preset scaled-down coefficient and a prototype of the sea surface; and combining the scaled-down model of the target with the scaled-down model of the sea surface to obtain a coupled scaled-down model of the target and the sea surface. This method overcomes the problems of RCS and scattering center deviations encountered in traditional scaled-down construction methods, and features high accuracy and low cost.

[0072] This invention addresses the scaled-down testing requirements of a coupled model of a dynamic sea surface and a low-scattering target. It constructs a scaled-down low-scattering target using engineering approximation methods based on stealth materials and scattering source models. Based on the scaled-down construction theory of flexible thin films, it employs stretchable flexible film design and high-precision digital control technology for the overall morphology of the film to design and fabricate a scaled-down sea surface simulation system using stretchable flexible thin films. By controlling the real-time height parameters at the flexible thin film array points according to the dynamic wave height variation law, the system achieves high-precision simulation of a dynamic scaled-down sea surface using flexible films.

[0073] This invention performs simulation calculations on the composite scattering of the prepared flexible thin film simulation sample with the target, which can provide technical support for the testing of the characteristics of marine environmental targets.

[0074] This invention can be applied to the detection and identification of aircraft and ships in marine environments. It also has the advantages of being thin, lightweight, and low-cost, making it a complex scaled-down stealth material product with promising applications. Attached Figure Description

[0075] Figure 1 This is a flowchart of a method for constructing a coupled scaled model of a low-scattering target and the sea surface according to an embodiment of the present invention;

[0076] Figure 2 This is a three-dimensional model of the periodic structure of the prototype material of the honeycomb absorbing plate in a method for constructing a coupled scaled model of a low-scattering target and the sea surface provided in an embodiment of the present invention.

[0077] Figure 3 This is an example of the reflectivity equivalent design of the prototype material of the honeycomb absorbing plate in a method for constructing a coupled scaled model of a low-scattering target and the sea surface provided in an embodiment of the present invention.

[0078] Figure 4 This is a method for constructing a coupled scaled model of a low-scattering target and a sea surface, provided by an embodiment of the present invention, which uses a periodic structure of a surface material selected by frequency selection.

[0079] Figure 5 This is an equivalent circuit model diagram of the frequency-selective surface material in a method for constructing a coupled scaled model of a low-scattering target and sea surface provided by an embodiment of the present invention;

[0080] Figure 6 This is a transmission coefficient and reflection coefficient curve of the prototype material of the frequency-selective surface in a method for constructing a coupled scaled model of a low-scattering target and the sea surface provided in an embodiment of the present invention;

[0081] Figure 7 This is a comparison curve of the equivalent reflection coefficient and simulated reflection coefficient of the prototype material of the frequency-selective surface in a method for constructing a coupled scaled model of a low-scattering target and sea surface provided in an embodiment of the present invention;

[0082] Figure 8 This is a comparison curve of the equivalent reflection coefficient of the scaled material of the frequency-selective surface and the simulated reflection coefficient of the prototype material of the frequency-selective surface in a method for constructing a coupled scaled model of a low-scattering target and the sea surface provided in an embodiment of the present invention.

[0083] Figure 9(a) is a comparison of the reflection coefficient amplitudes of the prototype sea surface and the scaled-down sea surface under vertical polarization in a method for constructing a coupled scaled-down model of a low-scattering target and sea surface provided in an embodiment of the present invention.

[0084] Figure 9(b) is a comparison of the reflection coefficient amplitudes of the prototype sea surface and the scaled-down sea surface under horizontal polarization in a method for constructing a coupled scaled-down model of a low-scattering target and sea surface provided in an embodiment of the present invention.

[0085] Figure 10 This is a schematic diagram of the control device in a method for constructing a coupled scaled model of a low-scattering target and the sea surface according to an embodiment of the present invention;

[0086] Figure 11 This is a schematic diagram of the structure of a coupled scaled-down model of a low-scattering target and the sea surface provided in an embodiment of the present invention;

[0087] Figure 12 This is an RCS curve of a coupled scaled model of a low-scattering target and the sea surface provided in an embodiment of the present invention. Detailed Implementation

[0088] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the method for constructing a coupled scaled model of a low-scattering target and the sea surface proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise scales, used only to facilitate and clearly illustrate the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, scales, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0089] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0090] Combined with appendix Figures 1-12 As shown, this embodiment provides a method for constructing a coupled scaled model of a low-scattering target and a sea surface, including: step S1, constructing a scaled model of the target based on a preset scaling factor and a prototype of the target; step S2, constructing a scaled model of the sea surface based on a flexible dielectric film and a prototype of the sea surface; and step S3, combining the scaled model of the target with the scaled model of the sea surface to obtain a coupled scaled model of the target and the sea surface.

[0091] It is understood that the target includes a metal component and a non-metallic component disposed on the surface of the metal component, and step S1 includes: step S11, reducing the prototype of the metal component according to the preset scaling factor to construct a scaled-down model of the metal component; step S12, constructing a scaled-down material of the non-metallic component using a genetic algorithm according to the preset scaling factor and the prototype material of the non-metallic component; step S13, preparing a scaled-down model of the non-metallic component using the scaled-down material of the non-metallic component, preferably, the scaled-down material of the non-metallic component can be prepared into a scaled-down model of the non-metallic component by a spraying process or a calendering process; and step S14, combining the scaled-down model of the metal component and the scaled-down model of the non-metallic component according to the prototype of the target to obtain a scaled-down model of the target.

[0092] Specifically, in this embodiment, the target is a low-scattering target. A representative low-scattering target scaled-down model is constructed by analyzing the scattering source and scaled-down model characteristics of the target. For the metal component in the target, the scaled-down model of the metal component prototype is obtained by proportionally reducing its dimensions (including length, width, height, thickness, and radius) according to the preset scaled-down coefficient s. Optionally, the preset scaled-down coefficient s can be 4; the target is an aircraft, missile, ship, etc., and the metal component is the main body of the target, but this invention is not limited thereto.

[0093] Specifically, in this embodiment, the prototype material of the non-metallic component may include a coating-type stealth material and a structural stealth material. Correspondingly, the scaled-down material of the non-metallic component includes a coating-type scaled-down stealth material and a structural scaled-down stealth material. Specifically, the coating-type scaled-down stealth material can be prepared as a scaled-down model of the non-metallic component through a spraying process; the structural scaled-down stealth material can be prepared as a scaled-down model of the non-metallic component through a calendering process. More specifically, the coating-type scaled-down stealth material can be simulated based on the oblique reflection coefficient and constructed using a single-layer coating, i.e., designing a scaled-down material with a metal substrate while ensuring that the oblique reflection coefficient of the coating-type scaled-down stealth material is approximately similar to its prototype material (i.e., the coating-type stealth material). The specific construction method of the coating-type scaled-down stealth material can refer to existing methods, which will not be elaborated here, but the present invention is not limited thereto.

[0094] Specifically, in this embodiment, the structural stealth material mainly includes wave-transmitting materials, wave-absorbing materials, and frequency-selective materials. Correspondingly, the structural scaled-down stealth material includes wave-transmitting scaled-down materials, wave-absorbing scaled-down materials, and frequency-selective scaled-down materials. For the wave-transmitting scaled-down stealth material, the transmission coefficient of the wave-transmitting material (including various radome plates, glass plates, etc.) is simulated and calculated to ensure that the transmission coefficient (i.e., the transmission coefficient) and the reflection coefficient of the wave-transmitting scaled-down stealth material are approximately the same. Furthermore, the specific construction method of the wave-transmitting scaled-down stealth material can refer to existing methods, which will not be elaborated here, but the present invention is not limited thereto.

[0095] Please also refer to Figure 1 and Figure 2 For the aforementioned microwave absorbing material, a microwave absorbing material with a honeycomb structure can be taken as an example. In this case, the non-metallic component includes a honeycomb microwave absorbing plate, and step S12 includes: step S121, obtaining the composition of a scaled-down material of the honeycomb microwave absorbing plate based on the prototype material of the honeycomb microwave absorbing plate; the composition of the scaled-down material of the honeycomb microwave absorbing plate includes first microwave absorbing particles and a binder, and the volume ratio of the first microwave absorbing particles in the scaled-down material of the honeycomb microwave absorbing plate is a first addition ratio, and the thickness of the scaled-down material of the honeycomb microwave absorbing plate is a first thickness; optionally, the first microwave absorbing particles are carbonyl iron powder, carbon powder, carbon nanotubes, ferrite, etc.; the binder is epoxy resin, silicone rubber, EPDM rubber, etc. Step S122: Using the first addition ratio and the thickness as optimization variables, and constructing a first optimization objective function based on the cumulative deviation between the reflectivity of the scaled-down material of the honeycomb absorbing plate and the reflectivity of the prototype material of the honeycomb absorbing plate under different incident angles of electromagnetic waves; Step S123: Solving the first optimization objective function using the genetic algorithm to obtain the first addition ratio and the first thickness corresponding to the minimum value of the first optimization objective function, and taking them as the optimal first addition ratio and the optimal first thickness; and Step S124: Constructing the scaled-down material of the honeycomb absorbing plate based on the optimal first addition ratio and the optimal first thickness.

[0096] Specifically, in this embodiment, the prototype material of the honeycomb absorbing plate includes a honeycomb skeleton and an absorbing agent filled within the honeycomb skeleton; wherein, the honeycomb skeleton includes a plurality of interconnected hexagonal rings, and the outer side length t of each hexagonal ring in the honeycomb skeleton can be 5mm to 9mm, and the ring width d0 can be 1mm to 3mm; the height H of the honeycomb skeleton is 1mm to 10mm, and the equivalent periodic structure model is as follows. Figure 2As shown; the absorbing agent can be flake carbonyl iron powder, carbon black, graphite, etc., and the volume fraction of the absorbing agent is usually between 5% and 30%. Further, before performing step S122, the method includes: at the simulation frequency, using CST software to perform simulation calculations on the prototype material of the honeycomb absorbing plate to obtain the reflectivity of the prototype material; and when importing the prototype material of the honeycomb absorbing plate into the CST software platform for simulation calculation, setting the dielectric constant ε0 and permeability μ0 of the prototype material, the simulation frequency f0 (range 1 GHz to 18 GHz), and after setting the incident angle parameters, the incident angle range is 0° to 90°, and the preset interval angle can be 5°, 8.5°, 10°, etc. More specifically, the absorbing agent is selected as 20% sheet-like carbonyl iron material, the simulation frequency f0 is 7.82 GHz, the incident angle range is 0° to 90°, and the preset interval angle is 8.5°. The reflectivity of the prototype material of the honeycomb absorbing plate is calculated in CST software, and the calculation results are as follows: Figure 3 As shown; from Figure 3 As can be seen, the reflectivity of the prototype material of the honeycomb absorbing plate is similar to that of the equivalent material of the flat plate. Its vertical polarization curve and curve function curve are quite close, while the horizontal polarization curve shows a trend of first decreasing and then increasing. Therefore, for the scaled-down material of the honeycomb absorbing plate, using an isotropic homogeneous material for equivalent design can achieve a reflectivity that is basically consistent with the reflectivity of the prototype material of the honeycomb absorbing plate. Thus, the scaled-down material of the honeycomb absorbing plate can be an isotropic homogeneous absorbing material, that is, the scaled-down material of the honeycomb absorbing plate is an absorbing material formed by mixing the first absorbing particles and the binder and having the first thickness. However, this invention is not limited to this.

[0097] Specifically, in this embodiment, before performing step S122, the method further includes: calculating the reflectivity of the scaled-down material of the honeycomb panel at the first scaled-down frequency according to a relevant formula. More specifically, when the electromagnetic wave is incident on the surface of the non-metallic component, it mainly includes two modes: TE mode (i.e., vertical polarization) and TM mode (i.e., horizontal polarization); the reflectivity of the scaled-down material of the honeycomb absorbing panel is calculated using the following formula:

[0098]

[0099]

[0100]

[0101]

[0102]

[0103] Wherein, RL represents the reflectivity of the scaled-down material of the honeycomb absorbing plate; Z in The wave impedance of the scaled-down material of the honeycomb absorbing panel is represented by η0; η0 represents the vacuum wave impedance, and η0 = 377Ω; θ0 represents the incident angle of the electromagnetic wave; Z TE Z represents the wave impedance when the electromagnetic wave is in TE mode; TM The impedance represents the electromagnetic wave in TM mode; θ represents the refraction angle of the electromagnetic wave; μ r1 ε represents the permeability of the scaled-down material of the honeycomb absorbing plate. r1 The dielectric constant of the scaled-down material of the honeycomb absorbing plate is μ. r1 and ε r1 Determined by the first addition ratio; d1 represents the first thickness; c represents the speed of light in a vacuum; f s This represents the first scaling frequency, which is the product of the preset scaling factor and the simulation frequency, i.e., f. s =sf0; j represents the imaginary unit, and

[0104] As can be seen from formulas (1) to (5), the reflectivity of the scaled-down material of the honeycomb absorbing plate is a function of the electromagnetic parameters (including permeability and dielectric constant) of the absorbing material and the first thickness. Since the electromagnetic parameters of the absorbing material are functions of the first addition ratio, the reflectivity of the scaled-down material of the honeycomb absorbing plate can be regarded as a function of the first addition ratio and the first thickness. Therefore, the final optimization variables are the first addition ratio and the first thickness. The first optimization objective function is expressed by the following formula:

[0105]

[0106] Where F0 represents the cumulative deviation between the reflectivity of the scaled-down material of the honeycomb absorbing panel and the reflectivity of the prototype material of the honeycomb absorbing panel under different incident angles of the electromagnetic wave; n represents the total number of incident angles, and since the range of the incident angles is 0 to 90°, then n = [90° / Δθ] + 1, and Δθ represents the preset interval angle, [] represents rounding, and θ0 i Let θ represent the i-th incident angle. For example, when the preset interval angle Δθ is 8.5°, n = 11, meaning there are a total of 11 incident angles, and the first incident angle θ0... 1 =0, the second incident angle θ0 2 = 8.5°, the third incident angle θ0 3 =17°, the fourth incident angle θ0 4 =25.5°, the fifth incident angle θ05 =34°, the 6th incident angle θ0 6 = 42.5°, the 7th incident angle θ0 7 =51°, the 8th incident angle θ0 8 =59.5°, the 9th incident angle θ0 9 =68°, the 10th incident angle θ0 10 =76.5°, the 11th incident angle θ0 11 =85°; vol represents the first addition ratio; RL(vol,d1,θ0) i ) represents the reflectivity of the prototype material of the honeycomb absorbing panel; RL0(θ0) i ) represents the reflectivity of the prototype material of the honeycomb absorbing plate.

[0107] Specifically, in this embodiment, before performing step S123, samples of the absorbing material with first addition ratios (vol) of 0%, 10%, 20%, 30%, 40%, and 50% can be prepared in advance, and electromagnetic parameter tests can be performed on each sample to obtain the electromagnetic parameter values ​​of each sample. Subsequently, based on the first addition ratio and electromagnetic parameter values ​​of the samples, the electromagnetic parameter values ​​corresponding to other addition ratios can be obtained using Lagrange interpolation theory, thereby establishing an electromagnetic parameter library of the absorbing materials with different first addition ratios, laying the foundation for the selection of electromagnetic parameters when constructing the scaled-down material of the honeycomb absorbing plate. Furthermore, in step S123, when using the genetic algorithm to solve the first optimization objective function, the crossover factor can be selected as 0.9, the mutation factor as 0.05, the initial population size as 800, and the maximum number of iterations as 10. After solving, the optimal first thickness is 1.8133 mm, and the optimal first addition ratio when the first absorbing microparticle is carbonyl iron powder is 10.65%. At this time, the total deviation of the reflectivity curves of the scaled-down material and the prototype material of the honeycomb absorbing plate is only 2.7531 dB, which meets the requirements of scaled-down measurement. However, the present invention is not limited to this.

[0108] Please also refer to Figure 4 and Figure 5The non-metallic component may further include a frequency selective surface. In this case, step S12 includes: Step S125: Obtaining the periodic structure of a scaled-down material of the frequency selective surface based on the prototype material of the frequency selective surface; the periodic structure of the scaled-down material of the frequency selective surface includes a scaled-down substrate medium and a scaled-down square ring disposed on the scaled-down substrate medium, and the scaled-down square ring is provided with a scaled-down gap; Step S126: Performing simulation calculations on the prototype material of the frequency selective surface to obtain the simulated reflection coefficient of the prototype material of the frequency selective surface; Step S127: Calculating the equivalent reflection coefficient of the scaled-down material of the frequency selective surface according to the formula for calculating the equivalent reflection coefficient of the frequency selective surface material; Step S128: Combining the periodic length of the scaled-down square ring, the thickness of the scaled-down substrate medium, and the scaled-down gap... Width is used as an optimization variable, and a second optimization objective function is constructed based on the cumulative deviation between the equivalent reflection coefficient of the scaled material of the frequency-selective surface and the simulated reflection coefficient of the prototype material of the frequency-selective surface at different frequencies; Step S129: The genetic algorithm is used to solve the second optimization objective function to obtain the period length of the scaled square ring, the thickness of the scaled substrate medium, and the width of the scaled gap corresponding to the minimum value of the second optimization objective function, and these are taken as the optimal period length of the scaled square ring, the optimal thickness of the scaled substrate medium, and the optimal width of the scaled gap; and Step S130: The scaled material of the frequency-selective surface is constructed based on the optimal period length of the scaled square ring, the optimal thickness of the scaled substrate medium, and the optimal width of the scaled gap.

[0109] Specifically, in this embodiment, the frequency selective surface structure can be calculated and fitted using the equivalent circuit method. The frequency selective surface material is a bandpass material, and the square ring frequency selective surface structure can be described using an equivalent circuit model, such as... Figure 5 As shown, the formula for calculating the equivalent reflection coefficient of the frequency-selective surface material is:

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117] Wherein, R represents the equivalent reflection coefficient of the frequency-selective surface material; Z inp Z represents the input impedance of the frequency-selective surface material; Z0 represents the wave impedance when incident obliquely in a vacuum, η0 is the vacuum wave impedance, and η0 = 377Ω; Z g′ Z represents the impedance of the metal mesh in the frequency-selective surface. d Let β represent the impedance of the substrate medium, d represent the propagation constant of the substrate medium, d represent the thickness of the substrate medium, μ² represent the permeability of the substrate medium, and ε represent the dielectric constant. r2 Let ω represent the dielectric constant of the substrate medium; θ0 represent the incident angle of the electromagnetic wave; θ represent the angle of refraction of the electromagnetic wave; c represent the speed of light in a vacuum; f represent the frequency; and j represent the imaginary unit. η represents the wave impedance of the substrate medium, α represents the material coefficient of the frequency-selective surface, k is the wave number in vacuum, A represents the first fitting parameter, B represents the second fitting parameter, D represents the period length of the square ring, and w represents the width of the slit.

[0118] Specifically, in this embodiment, the periodic structure of the prototype material of the frequency selective surface includes a prototype substrate medium and prototype square rings disposed on the prototype substrate medium, each prototype square ring having a prototype gap; wherein, the prototype substrate medium is PF4, the thickness of the prototype substrate medium is 1-3 mm (preferably 2 mm), and the dielectric constant of the prototype substrate medium is 4.5-j0.11; the periodic length of the prototype square ring is 10-16 mm (preferably 16 mm), the inner side length of the prototype square ring is 6-8 mm (preferably 8 mm), the thickness of the prototype square ring is 0.01-0.03 mm (preferably 0.02 mm), and the conductivity of the prototype square ring is 5×10^7 S / m-7×10^7 S / m (preferably 6×10^7 S / m); the width of the prototype gap is 1-2 mm (preferably 2 mm). More specifically, in step S126, the prototype material of the frequency-selective surface can be imported into CST software, and the CST software can be used to perform simulation calculations on the prototype material of the frequency-selective surface to obtain the simulated reflection coefficient of the prototype material of the frequency-selective surface; and the calculation results of the simulated reflection coefficient of the prototype material of the frequency-selective surface at different frequencies are as follows: Figure 6 As shown; from Figure 6 As can be seen from the simulation, the reflection coefficient S of the prototype material of the frequency-selective surface in the 1-8 GHz range is... 11 and simulated transmission coefficient S 12The two trends are diametrically opposed, with a peak at 5.82 GHz, which is the midpoint of the bandpass frequency, and a half-peak bandwidth of 5.03-6.71 GHz. Furthermore, the frequency selection surface pattern can also be a ring, a cross, or other patterns, but this invention is not limited to these.

[0119] Specifically, in this embodiment, before executing step S127, the method further includes: at the prototype frequency, substituting the parameters of the prototype material of the frequency selective surface (including the period length of the prototype square ring, the width of the prototype gap, and the propagation constant, thickness, permeability, dielectric constant, wave impedance, etc. of the prototype substrate medium) into the equivalent reflection coefficient calculation formula of the frequency selective surface material, i.e., formulas (7) to (13), to obtain the equivalent reflection coefficient of the prototype material of the frequency selective surface; at this time, the first fitting parameter A and the second fitting parameter B are unknowns, i.e., the equivalent reflection coefficient of the prototype material of the frequency selective surface is an expression about the first fitting parameter A and the second fitting parameter B; then, the first fitting parameter A and the second fitting parameter B are used as Optimize variables and construct a fitting parameter optimization objective function based on the cumulative deviation between the equivalent reflection coefficient of the prototype material of the frequency-selective surface and the simulated reflection coefficient of the prototype material of the frequency-selective surface at different frequencies; then, use the genetic algorithm to solve the fitting parameter optimization objective function to obtain the first fitting parameter A and the second fitting parameter B corresponding to the minimum value of the fitting parameter optimization objective function, and substitute them as the optimal first fitting parameter A and the optimal second fitting parameter B into formula (13) in the formula for calculating the equivalent reflection coefficient of the frequency-selective surface material. At this time, the first fitting parameter A and the second fitting parameter B in the formula for calculating the equivalent reflection coefficient of the frequency-selective surface material are both known values. More specifically, the fitting parameter optimization function is expressed as follows:

[0120]

[0121] Where F4 represents the cumulative deviation between the equivalent reflection coefficient and the simulated reflection coefficient of the prototype material of the frequency-selective surface at different frequencies; N is the number of frequency points, f i Let R(A, B) represent the i-th frequency point; R(A, B) represents the equivalent reflection coefficient of the prototype material of the frequency-selective surface; S 11 This represents the simulated reflection coefficient of the prototype material of the frequency-selective surface. From... Figure 7 The results show that the optimized function value F4 is 0.2, the optimal first fitting parameter A = 1.88, and the optimal second fitting parameter B = 0.282.

[0122] Specifically, in this embodiment, given that the first fitting parameter A and the second fitting parameter B are known, the period length of the scaled square ring, the thickness of the scaled substrate medium, and the width of the scaled gap in the scaled material of the frequency selection surface are optimized at the second scaled frequency. At this time, the corresponding second scaled frequency and prototype frequency are amplified, and the amplification factor corresponds to the preset scaled coefficient; and the second optimization objective function is expressed by the following formula:

[0123]

[0124] Wherein, F2 represents the cumulative deviation between the equivalent reflection coefficient of the scaled-down material of the frequency-selective surface and the simulated reflection coefficient of the prototype material of the frequency-selective surface at different frequencies; N represents the total number of frequency points; f I Represents the i-th frequency point; R(D, w, d) represents the equivalent reflection coefficient of the scaled-down material of the frequency-selective surface; S 11 The simulated reflection coefficient represents the prototype material of the frequency-selective surface.

[0125] More specifically, in this embodiment, after solving the second optimization function using the genetic algorithm, the optimal period length of the scaled-down square ring in the scaled-down material of the frequency-selective surface is 3.9 mm, the optimal width of the scaled-down gap is 1.05 mm, and the optimal thickness of the scaled-down substrate medium is 0.49 mm. The fitted curve is then compared as follows... Figure 8 As shown, the deviation between the two is less than 0.2, which meets the requirements of the scaled-down test, but the present invention is not limited thereto.

[0126] Please refer to Figures 9(a), 9(b), and 9(c) simultaneously. Figure 10The construction of the scaled-down model of the sea surface mainly includes two aspects: first, the construction of the dielectric constant of the sea surface, and second, the construction of the surface morphology of the sea surface. Specifically, the steps for constructing the scaled-down model of the sea surface include: Step S21, the scaled-down material of the sea surface uses the flexible dielectric film; and the components of the flexible dielectric film include microwave absorbing particles and rubber, the volume proportion of the microwave absorbing particles in the flexible dielectric film is a second addition ratio; Step S22, calculate the reflection coefficient of the scaled-down material of the sea surface and the reflection coefficient of the prototype sea surface according to the formula for calculating the reflection coefficient of the sea surface; Step S23, use the second addition ratio as an optimization variable, and calculate the reflection coefficient of the scaled-down material of the sea surface and the reflection coefficient of the prototype sea surface under different electromagnetic waves. Step S24: The cumulative deviation value at the incident angle is used to construct a third optimization objective function; Step S25: The genetic algorithm is used to solve the third optimization objective function to obtain the second addition ratio corresponding to the minimum value of the third optimization objective function and use it as the optimal second addition ratio; Step S26: The flexible dielectric film is prepared according to the optimal second addition ratio; Step S27: Several array points are set on the prepared flexible dielectric film; and Step S28: The position of each array point is adjusted according to the shape change data of the sea surface prototype to construct a scaled-down model of the sea surface.

[0127] It is understandable that the formula for calculating the reflection coefficient of the sea surface is:

[0128]

[0129] Where R′ represents the reflection coefficient of the sea surface; θ0 represents the incident angle of the electromagnetic wave; ε r3 Let be the complex relative permittivity of the sea surface.

[0130] Specifically, in this embodiment, the scaled-down material of the sea surface is the flexible dielectric film. The dielectric constant of the sea surface is determined by fitting the seawater surface reflection coefficient, and the surface shape is controlled by adjusting the displacement of array points on the flexible film. The electromagnetic parameters of the scaled-down material of the sea surface are optimized using the principle of the high-frequency approximation algorithm, "physical optics." More specifically, an electromagnetic wave incident angle of 0–90° is selected, and the variation curve of the reflection coefficient amplitude of the scaled-down material of the sea surface with the electromagnetic wave incident angle θ0 is obtained.

[0131] Specifically, in this embodiment, the reflection coefficient R′ of the prototype of the sea surface is calculated. 原型Based on the variation of the complex relative permittivity of seawater with frequency, a prototype frequency of 7.8 GHz was selected (the intermediate frequency between 7.75 and 7.85 GHz was chosen as representative), with a temperature of 20℃ and a salinity of 35‰. The prototype complex relative permittivity of the sea surface was then calculated to be 61-j36, i.e., R′ was calculated. 原型 ε r3 The value is 61-j36. At this time, the reflection coefficient of the prototype of the sea surface can be obtained according to formula (16), but the present invention is not limited to this.

[0132] Specifically, in this embodiment, the reflection coefficient R′ of the scaled-down material of the sea surface is calculated. 缩比 When the preset scaling factor is selected as 4, the third scaling frequency is 31.2 GHz. For the thin film medium on its surface, the second absorbing particle can be carbon black, and the rubber can be silicone rubber. The complex relative permittivity of the material that meets the conditions is obtained through the third optimization objective function, so that the reflection coefficient R′ of the scaled material on the sea surface is... 缩比 The reflection coefficient R′ of the prototype of the sea surface 原型 They are approximately equal, and the third optimization objective function is expressed by the following formula:

[0133]

[0134] Wherein, F3 represents the cumulative deviation between the reflection coefficient of the scaled-down material of the sea surface and the reflection coefficient of the prototype sea surface at different incident angles; θ0 represents the incident angle of the electromagnetic wave, ranging from 0 to 90°, with a step size of 1°; R′ 原型 R′ represents the reflection coefficient of the prototype of the sea surface. 缩比 R′ represents the reflection coefficient of the scaled-down material of the sea surface. 缩比 ε r3 It is determined by the second addition ratio.

[0135] More specifically, it can be seen from formula (16) that R′ 缩比 The dielectric constant of the scaled-down material of the sea surface is a function of the dielectric constant of the scaled-down material, which can also be expressed as a function of the second addition ratio. Therefore, the final optimization variable is determined to be the second addition ratio. The purpose of optimization is to minimize the third objective function, ensuring that the difference between the reflection coefficients of the prototype sea surface and the scaled-down sea surface under different incident angles of electromagnetic waves is minimized, thereby obtaining the optimal second addition ratio. After optimization calculation, the optimal second addition ratio is found, such that the complex relative dielectric constant of the scaled-down material of the sea surface is 62-j32, which can be used to construct the flexible thin film medium of the scaled-down sea surface. Figures 9(a) and 9(b) show the comparison of the reflection coefficient amplitudes of the prototype sea surface and the scaled-down sea surface under two polarizations.

[0136] Specifically, in this embodiment, based on the dynamic shape change pattern of the sea surface, a control device is used to regulate the position of each array point in the flexible dielectric film. The control device includes: a computer for storing shape change data of the sea surface prototype; several telescopic rods, each telescopic rod positioned below a corresponding array point; a motor unit connected to the telescopic rods for driving the telescopic rods to extend and retract vertically; and a servo system connected to both the computer and the motor unit for controlling the motor unit to drive the telescopic rods to extend and retract according to the shape change data of the sea surface prototype, thereby regulating the position of each array point. More specifically, as... Figure 10 As shown, the flexible dielectric film, all the telescopic rods, and the motor assembly can form a flexible sea surface device, mainly used for the dynamic generation of a scaled-down model of the sea surface. The servo system is mainly used to control the input and output of the motors in the flexible sea surface device, ensuring that the array motors can operate synchronously to obtain the desired values ​​of the array point positions on the sea surface. The computer is mainly used to control the servo system, providing position information of each array point as the sea surface changes over time, as well as adjusting the speed of position change. Optionally, the telescopic rods are made of wave-transparent material to prevent the array's telescopic rods from generating additional scattering; the motors are equipped with wave-absorbing material to absorb excess transmitted clutter and prevent additional scattering from the bottom metal motor, but the present invention is not limited thereto.

[0137] Furthermore, in this embodiment, the target can be a ship, wherein the metal components are directly constructed using conductors such as aluminum alloy, and the non-metallic components use honeycomb absorbing panels. Considering the complexity of the honeycomb structure, an equivalent dielectric material is used for construction during actual simulation. For the sea surface, a deep-sea surface model and an equivalent sea surface model are used for construction; and the coupled scaled model of the target and the sea surface is as follows. Figure 11 As shown, the RCS before and after equivalence is compared. More specifically, the coupled scaled-down model of the target and the sea surface is simulated using the bouncing ray method on the FEKO software platform, which can easily obtain the RCS of the composite scattering model. The results are as follows. Figure 12As shown in the figure, the comparison reveals that the composite model of the ship and the sea surface (i.e., the coupled scaled model of the target and the sea surface) remains essentially consistent before and after equivalence as the angle increases, with an average deviation of 0.12 dB within the range of 0° to 90°. The deviation is generally less than 0.5 dB within the range of 0° to 20°, while it fluctuates somewhat within the range of 20° to 70°, with the maximum RCS deviation reaching 2 dB. Within the range of 70° to 90°, the RCS deviation decreases to less than 0.5 dB. Furthermore, comparing the RCS of the low-scattering ship composite model under the sea surface with the simple sea surface RCS, it can be seen that when electromagnetic waves are incident within the 0° to 80° angle range, the influence of the sea surface edge thickness is negligible. At this point, there is a significant difference between composite scattering and simple sea surface scattering between 20° and 60°, mainly due to the dihedral angle between the ship's island and the deck. However, between 70° and 80°, the scattering brought by the ship in the marine environment is negligible, indicating that the low-scattering ship used in this embodiment scatters less in this orientation.

[0138] In summary, this embodiment discloses a method for constructing a coupled scaled-down model of a low-scattering target and a sea surface, comprising: constructing a scaled-down model of the target based on a preset scaled-down coefficient and a prototype of the target; constructing a scaled-down model of the sea surface based on a flexible dielectric thin film and a prototype of the sea surface; and combining the scaled-down model of the target and the scaled-down model of the sea surface to obtain a coupled scaled-down model of the target and the sea surface. This method overcomes the problems of RCS and scattering center deviations encountered in traditional scaled-down construction methods, and features high accuracy and low cost. This embodiment can be applied to the detection and identification of aircraft and ship targets in marine environments, and also has the advantages of thinness, light weight, and low cost, making it a complex scaled-down stealth material product with promising applications.

[0139] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for constructing a coupled scaled model of a low-scattering target and the sea surface, characterized in that, include: Based on the preset scaling factor and the prototype of the target, a scaled-down model of the target is constructed; Based on a flexible dielectric film, a scaled-down model of the sea surface is constructed according to the prototype of the sea surface. as well as The scaled-down model of the target is combined with the scaled-down model of the sea surface to obtain a coupled scaled-down model of the target and the sea surface; The steps for constructing the scaled-down model of the sea surface include: The scaled-down material of the sea surface is the flexible dielectric film; and the components of the flexible dielectric film include microwave absorbing particles and rubber, wherein the volume ratio of the microwave absorbing particles in the flexible dielectric film is a second addition ratio; Calculate the reflection coefficient of the scaled-down material of the sea surface and the reflection coefficient of the original sea surface according to the formula for calculating the reflection coefficient of the sea surface. The second addition ratio is used as the optimization variable, and a third optimization objective function is constructed based on the cumulative deviation between the reflection coefficient of the scaled-down material of the sea surface and the reflection coefficient of the prototype of the sea surface under different incident angles of electromagnetic waves. A genetic algorithm is used to solve the third optimization objective function to obtain the second addition ratio corresponding to the minimum value of the third optimization objective function, and this ratio is taken as the optimal second addition ratio. The flexible dielectric film is prepared according to the optimal second addition ratio; A plurality of array points are formed on the prepared flexible dielectric film; and Based on the shape change data of the prototype sea surface, the position of each array point is adjusted to construct a scaled-down model of the sea surface.

2. The method for constructing a coupled scaled model of a low-scattering target and sea surface as described in claim 1, characterized in that, The target includes a metal component and a non-metallic component disposed on the surface of the metal component, and the step of constructing a scaled-down model of the target includes: The prototype of the metal part is scaled down according to the preset scaling factor to construct a scaled-down model of the metal part; Based on the preset scaling factor and the prototype material of the non-metallic component, a genetic algorithm is used to construct the scaled-down material of the non-metallic component; A scaled-down model of the non-metallic component is prepared using a scaled-down material of the non-metallic component; and Based on the prototype of the target, the scaled-down models of the metal parts and the non-metal parts are combined to obtain the scaled-down model of the target.

3. The method for constructing a coupled scaled model of a low-scattering target and sea surface as described in claim 2, characterized in that, The non-metallic component includes a honeycomb absorbing plate, and the step of constructing the scaled-down material of the non-metallic component includes: Based on the prototype material of the honeycomb absorbing plate, the composition of the scaled-down material of the honeycomb absorbing plate is obtained; the composition of the scaled-down material of the honeycomb absorbing plate includes first absorbing microparticles and binder, and the volume ratio of the first absorbing microparticles in the scaled-down material of the honeycomb absorbing plate is a first addition ratio, and the thickness of the scaled-down material of the honeycomb absorbing plate is a first thickness. The first addition ratio and the thickness are used as optimization variables, and a first optimization objective function is constructed based on the cumulative deviation between the reflectivity of the scaled material of the honeycomb absorbing plate and the reflectivity of the prototype material of the honeycomb absorbing plate under different incident angles of electromagnetic waves. The genetic algorithm is used to solve the first optimization objective function to obtain the first addition ratio and the first thickness corresponding to the minimum value of the first optimization objective function, and these are taken as the optimal first addition ratio and the optimal first thickness; and The scaled-down material of the honeycomb absorbing panel is constructed according to the optimal first addition ratio and the optimal first thickness.

4. The method for constructing a coupled scaled model of a low-scattering target and sea surface as described in claim 3, characterized in that, The reflectivity of the scaled-down material of the honeycomb absorbing plate is calculated using the following formula: in, RL This represents the reflectivity of the scaled-down material of the honeycomb absorbing panel; Z in This represents the wave impedance of the scaled-down material of the honeycomb absorbing plate; η 0 represents vacuum wave impedance, and η 0 = 377Ω; θ 0 represents the incident angle of the electromagnetic wave; Z TE This indicates the wave impedance when the electromagnetic wave is in TE mode; Z TM This indicates the wave impedance when the electromagnetic wave is in TM mode; θ This represents the angle of refraction of the electromagnetic wave; μ r1 This indicates the permeability of the scaled-down material of the honeycomb absorbing plate. ε r1 The dielectric constant of the scaled-down material of the honeycomb absorbing plate is represented, and μ r1 and ε r1 Determined by the first addition ratio; d 1 represents the first thickness; c This represents the speed of light in a vacuum. f s Indicates the first scaling frequency; j Represents the imaginary unit, and ; The first optimization objective function is expressed by the following formula: in, F 1 represents the cumulative deviation between the reflectivity of the scaled-down material of the honeycomb absorbing plate and the reflectivity of the prototype material of the honeycomb absorbing plate under different incident angles of the electromagnetic wave; n This indicates the total number of incident angles. n =[90° / Δθ]+1, where Δθ represents the preset interval angle, and [ ] represents rounding; θ 0 i Indicates the first i The incident angles mentioned above; vol This indicates the first addition ratio; RL ( vol , d 1, θ 0 i () represents the reflectivity of the prototype material of the honeycomb absorbing panel; RL 0 ( θ 0 i () represents the reflectivity of the prototype material of the honeycomb absorbing plate.

5. The method for constructing a coupled scaled model of a low-scattering target and sea surface as described in claim 2, characterized in that, The non-metallic component includes a frequency-selective surface, and the step of constructing the scaled-down material of the non-metallic component includes: Based on the prototype material of the frequency selective surface, a periodic structure of a scaled-down material of the frequency selective surface is obtained; the periodic structure of the scaled-down material of the frequency selective surface includes a scaled-down substrate medium and a scaled-down square ring disposed on the scaled-down substrate medium, and the scaled-down square ring is provided with scaled-down gaps; The prototype material of the frequency selective surface is simulated to obtain the simulated reflection coefficient of the prototype material of the frequency selective surface. The equivalent reflection coefficient of the scaled-down material of the frequency-selective surface is calculated according to the formula for calculating the equivalent reflection coefficient of the surface material. The period length of the scaled square ring, the thickness of the scaled substrate medium, and the width of the scaled gap are used as optimization variables. A second optimization objective function is constructed based on the cumulative deviation between the equivalent reflection coefficient of the scaled material of the frequency-selective surface and the simulated reflection coefficient of the prototype material of the frequency-selective surface at different frequencies. The genetic algorithm is used to solve the second optimization objective function to obtain the period length of the scaled square ring, the thickness of the scaled substrate medium, and the width of the scaled gap corresponding to the minimum value of the second optimization objective function. These are taken as the optimal period length of the scaled square ring, the optimal thickness of the scaled substrate medium, and the optimal width of the scaled gap. The scaled material of the frequency-selective surface is constructed based on the optimal period length of the scaled square ring, the optimal thickness of the scaled substrate medium, and the optimal width of the scaled gap.

6. The method for constructing a coupled scaled model of a low-scattering target and sea surface as described in claim 5, characterized in that, The formula for calculating the equivalent reflection coefficient of the frequency-selective surface material is as follows: in, R This represents the equivalent reflection coefficient of the frequency-selective surface material; Z inp This indicates the input impedance of the frequency-selective surface material; Z 0 represents the wave impedance when incident obliquely in a vacuum. η 0 represents the vacuum wave impedance, and η 0 = 377Ω; This represents the impedance of the metal mesh in the frequency-selective surface; Z d Indicates the impedance of the substrate medium. β Represents the propagation constant of the substrate medium. d Indicates the thickness of the substrate medium. μ 2 represents the permeability of the substrate medium. ε r2 This represents the dielectric constant of the substrate medium. ω Indicates angular frequency; θ 0 represents the incident angle of the electromagnetic wave; θ Indicates the angle of refraction of electromagnetic waves; c This represents the speed of light in a vacuum. f Indicates frequency; j Represents the imaginary unit, and ; η Indicates the wave impedance of the substrate medium. α This represents the material coefficient of the frequency-selective surface. k The wave number in a vacuum. A Denotes the first fitted parameters. B Indicates the second fitting parameter; D Indicates the period length of the square ring; w Indicates the width of the gap; The second optimization objective function is expressed by the following formula: in, F 2 represents the cumulative deviation between the equivalent reflection coefficient of the scaled-down material of the frequency-selective surface and the simulated reflection coefficient of the prototype material of the frequency-selective surface at different frequencies; N This indicates the total number of frequency points; f I Indicates the first I One frequency point; R ( D, w, d ) represents the equivalent reflection coefficient of the scaled-down material of the frequency-selective surface; S 11 The simulated reflection coefficient represents the prototype material of the frequency-selective surface.

7. The method for constructing a coupled scaled model of a low-scattering target and sea surface as described in claim 1, characterized in that, The formula for calculating the reflection coefficient of the sea surface is: in, This represents the reflectance of the sea surface; θ 0 represents the incident angle of the electromagnetic wave. ε r3 Let be the complex relative permittivity of the sea surface; The third optimization objective function is expressed by the following formula: in, F 3 represents the cumulative deviation between the reflection coefficient of the scaled-down material of the sea surface and the reflection coefficient of the prototype of the sea surface at different incident angles; θ 0 represents the incident angle of the electromagnetic wave, ranging from 0 to 90°, with a step size of 1°; This represents the reflection coefficient of the prototype of the sea surface. The value represents the reflectance of the scaled-down material of the sea surface, and middle ε r3 It is determined by the second addition ratio.

8. The method for constructing a coupled scaled model of a low-scattering target and sea surface as described in claim 1, characterized in that, The position of each array point is adjusted using a control device, and the control device includes: A computer is used to store data on the shape changes of the sea surface prototype; Several telescopic rods, each of which is positioned below the corresponding array point; The motor unit is connected to the telescopic rod and is used to drive the telescopic rod to extend and retract in the vertical direction; The servo system is connected to the computer and the motor assembly respectively, and is used to control the motor assembly to drive the telescopic rod to extend and retract based on the shape change data of the sea surface prototype, so as to adjust the position of each array point.

9. The method for constructing a coupled scaled model of a low-scattering target and sea surface as described in claim 8, characterized in that, The telescopic rod is made of a wave-transparent material.

Images