Multispectral stealth skin and self-adaptive camouflage system thereof

Abstract

The invention provides a multispectral stealth skin and a self-adaptive camouflage system.The multispectral stealth skin comprises a low infrared emission layer, a microwave absorption layer and a heating layer which are sequentially connected from top to bottom, and the microwave absorption layer comprises a visible light stealth layer; the visible light stealth layer is an environmental mimicry film prepared from thermochromic capsules and polydimethylsiloxane through an injection molding process. The application comprises applying the multispectral stealth skin to an environment adaptive multispectral compatible stealth skin system, and the adaptive camouflage system comprises an environment identification unit, a control system unit and the multispectral stealth skin. Through the multispectral stealth skin and the self-adaptive camouflage system, the high radar-infrared stealth and environment self-adaptive visible light stealth capacity is achieved, and high commercialization value and popularization value are achieved.

Description

Technical Field

[0001] The present invention relates to the field of multi-band compatible stealth technology, and in particular to a multi-spectral stealth skin and an adaptive camouflage system thereof. Background Art

[0002] With the advancement of science and technology and the rapid development of strategic weapons, precision strikes based on multi-band combination and multi-gradient depth detection technology have become the mainstream of modern battlefields. Among them, the multi-gradient detection system composed of long-range radar detection, medium-range infrared detection and close-range visible light remote sensing has been widely used. Therefore, for various strategic equipment that need to be protected, having radar stealth, infrared stealth and visible light stealth at the same time can greatly improve the survival rate on the battlefield. For mobile military equipment such as tanks and chariots, visible light stealth needs to be adaptive to the surrounding environment. In summary, it is very important to develop a system with radar-infrared stealth and environmentally adaptive visible light stealth.

[0003] The existing compatible stealth skin is mainly radar-infrared compatible stealth, which is realized by artificially controlling electromagnetic parameters to achieve metamaterials with extraordinary physical properties such as negative refraction and perfect lenses. From a functional point of view, it is mainly divided into two types: 1. Achieving higher visible light transmittance with the thinnest possible thickness, mainly used in windows of aircraft, tanks and other equipment; 2. Sacrificing thickness and light transmittance to achieve lower infrared emissivity and wider microwave absorption. The former can be further compatible with visible light stealth due to its excellent light transmittance, but the radar-infrared stealth performance is poor, and the latter is difficult to be compatible with visible light stealth due to its opacity, but has excellent radar-infrared stealth performance. How to be compatible with visible light stealth and maintain excellent infrared-radar stealth performance has become the key point in the development of stealth technology.

[0004] Chinese patent CN117471404A discloses an adaptive camouflage skin electronic and adaptive stealth system, which adopts a vertical stacking structure of an infrared low-emission layer, a radar absorption layer and an adaptive color-changing layer from the outside to the inside, realizing a multifunctional integrated design of infrared stealth, visual stealth and radar stealth, and finally achieving a multi-band intelligent adaptive stealth effect that takes into account low radiation in the mid-to-far infrared band of 3 to 15um, effective radar absorption in a wide frequency band of 10-37.5Ghz and adaptive color change of 0.38 to 0.78um. The design idea of ​​the invention is to place the adaptive color-changing layer at the bottom, which limits the infrared-radar stealth performance to a certain extent. Although its red emissivity is relatively high and the absorption effect is not strong in the low frequency band of 2-10GHz, in terms of the construction of the adaptive system, the ambient light sensor used for background recognition can only transmit back single color data, which is powerless in the face of a complex color environment and has poor adaptability. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a multi-spectral stealth skin to solve the problem that conventional stealth skins in the prior art cannot achieve simultaneous stealth of radar, infrared light, and visible light and have poor adaptability to color.

[0006] In order to overcome the defects of the above-mentioned prior art, the present invention provides a multi-spectral stealth skin, which includes a low-infrared emission layer, a microwave absorption layer and a heating layer connected in sequence from top to bottom, and the microwave absorption layer includes a visible light stealth layer, and the visible light stealth layer is an environmental mimicry film prepared by an injection molding process of thermochromic capsules and polydimethylsiloxane.

[0007] The multi-spectral stealth skin of the present invention, through the structural design, can perform adaptive stealth against radar, infrared light and visible light, and has strong adaptability to complex color environments.

[0008] In a possible embodiment, the microwave absorption layer includes a first microwave loss layer, a second base layer, an environmental mimicking film, a first foam medium layer, a second microwave loss layer, a third base layer, a second foam medium layer, a third microwave loss layer, a fourth base layer, and a third foam medium layer, which are connected in sequence from top to bottom.

[0009] The present invention adopts the microwave absorption layer design of the above structure, and the overall three-layer microwave absorption layer design can absorb microwave signals. The microwave signals can be converted into heat by the middle three-layer microwave absorption layer through resonance absorption, dielectric loss, etc., thereby suppressing the reflection of microwaves and making it impossible for radar to detect, thereby achieving radar stealth and improving the microwave absorption rate.

[0010] In a possible implementation, the first foam medium layer, the second foam medium layer, and the third foam medium layer are made of polymethacrylimide, expandable polyethylene, or a composite material of polymethacrylimide and expandable polyethylene; the second base layer, the third base layer, and the fourth base layer are PET bases.

[0011] In a possible embodiment, the material of the first microwave loss layer, the second microwave loss layer and the third microwave loss layer is one of indium tin oxide, antimony tin oxide and aluminum-doped zinc oxide, or a composite material of indium tin oxide, antimony tin oxide and aluminum-doped zinc oxide; the sheet resistance of the first microwave loss layer and the second microwave loss layer is 220-280Ω / sq; the sheet resistance of the third microwave loss layer is 120-180Ω / sq.

[0012] By selecting the foam medium of the above-mentioned specific material, as well as the material selection and square resistance limitation of the microwave loss layer, the absorption effect of the microwave absorption layer is further improved.

[0013] In a possible embodiment, the low infrared emission layer includes an infrared wave intercepting layer, a first substrate layer, and an air dielectric layer connected in sequence from top to bottom, the infrared wave intercepting layer is made of one of indium tin oxide, antimony tin oxide and aluminum-doped zinc oxide and a composite material, and the square resistance of the infrared wave intercepting layer is 5-12Ω / sq; the first substrate layer is a PET substrate, and the air dielectric layer is obtained by laser engraving on the surface of the first substrate layer.

[0014] In a possible implementation, the infrared wave intercepting layer is fixed on the first substrate layer by photolithography and dry etching; the first microwave loss layer, the second microwave loss layer and the third microwave loss layer are respectively fixed on the second substrate layer, the third substrate layer and the fourth substrate layer by laser etching.

[0015] By fixing the infrared wave intercepting layer and the microwave loss layer, the absorption and suppression effects of the multi-spectral stealth skin of the present invention are further improved.

[0016] In a possible implementation, the heating layer is one of a graphene heating plate, a silicone heating plate and a ceramic heating plate, or a heating plate made of a composite material of graphene, silicone and ceramic.

[0017] By selecting the above-mentioned heating plate, it is possible to heat the environmental mimicry film, thereby changing its color and achieving invisibility.

[0018] In a possible implementation, the thermochromic capsule includes a composite material formed by combining one or more materials of two-stage color-changing, multi-stage color-changing, colorless-to-colored or colored-to-colorless temperature-changing capsules at different temperatures.

[0019] In a possible implementation, the thermochromic capsule is a thermochromic capsule that changes from grass green to khaki at 31°C.

[0020] In a possible implementation, the method for preparing the environmental mimicry film includes:

[0021] S1. The polydimethylsiloxane polydimethylsiloxane and SE1700 curing agent were stirred in a mass ratio of 10:1 to form a glue, and then the glue and the thermochromic capsule were mixed in a mass ratio range of 5:1 to 10:1;

[0022] S2. Place the mixture in S1 in an internal vacuum machine and then evacuate the vacuum chamber to a vacuum degree of less than 3.0×10 -3 Pa, let stand for 30 minutes;

[0023] S3. The vacuum chamber is restored to normal pressure and the mixture is taken out, and then the mixture is poured into the coaxial method mold and the simulated film mold, respectively, and then the mold is placed in an oven at 80°C for 2h;

[0024] S4. The mold is taken out and demoulded to obtain an environmental mimicry film.

[0025] Another technical problem to be solved by the present invention is to provide an adaptive camouflage system, which includes applying the multi-spectral stealth skin to an environmentally adaptive multi-spectral compatible stealth skin system to solve the problem that the existing stealth skin system cannot simultaneously take into account radar, infrared light, and visible light stealth.

[0026] In order to solve the above technical problems, the present invention provides an application of a multi-spectral stealth skin, the application comprising applying the multi-spectral stealth skin to an environment-adaptive multi-spectrum compatible stealth skin system, the stealth skin system comprising: an environment recognition unit, a control system unit and a multi-spectral stealth skin;

[0027] The environment recognition unit is connected to the control system unit and is used to collect the environment background image and convert it into an electrical signal and input it into the control system unit;

[0028] The control system unit is connected to the multi-spectral stealth skin, and is used to receive and analyze the electrical signal output by the environment recognition unit, and convert the electrical signal into a control information source of the multi-spectral stealth skin and input it into the multi-spectral stealth skin.

[0029] In a possible implementation, the working process of the environment-adaptive multi-spectrum compatible stealth skin system includes:

[0030] Visible light stealth: The background information is obtained through the environment recognition unit, and then the background information is converted into an electrical signal and input into the control system unit. The temperature of the heating layer of the multi-spectral stealth skin is changed through the control system unit, and then the environmental mimicry film is fitted with a color similar to the background, thereby realizing environmental mimicry, that is, visible light stealth;

[0031] Radar stealth: The microwave absorption layer of the multi-spectral stealth skin converts microwaves into heat by means of resonance absorption and dielectric loss, thereby suppressing the reflection of microwaves and making it impossible for radar to detect, thereby achieving radar stealth;

[0032] Infrared stealth: The infrared wave emissivity is suppressed through the low infrared emission layer, which hinders the emission of internal infrared waves, thereby avoiding the detection of target infrared waves by infrared detectors.

[0033] The present invention proposes an environment-adaptive multi-spectrum compatible stealth skin system, which can achieve low infrared emissivity (lower than 0.227), broadband microwave absorption (>90%) in the range of 2.53-34.56 GHz, and adaptive visible light stealth in a variety of environments such as grasslands and deserts. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of the environment-adaptive multi-spectrum compatible stealth skin system of the present invention;

[0035] Figure 1 Among them, 1. Environmental recognition unit; 2. Control system unit; 3. Multi-spectral stealth skin;

[0036] Figure 2 This is a structural analysis diagram of the multi-spectral stealth skin of the present invention;

[0037] Figure 2 Among them, 301, infrared wave interception layer; 302, first base layer; 303, air dielectric layer; 304, first microwave loss layer; 305, second base layer; 306, environmental mimic film; 307, first foam dielectric layer; 308, second microwave loss layer; 309, third base layer; 310, second foam dielectric layer; 311, third microwave loss layer; 312, fourth base layer; 313, third foam dielectric layer; 314, heating layer;

[0038] Figure 3 This is an electromagnetic parameter diagram of the multi-spectral stealth skin prepared in Example 1 of the present invention;

[0039] Figure 4 The flowchart of the control unit of the environment-adaptive multi-spectrum compatible stealth skin system of the present invention;

[0040] Figure 5 It is an algorithm flow framework diagram of the environment-adaptive multi-spectrum compatible stealth skin system of the present invention;

[0041] Figure 6 The diagram is a structural diagram of the dimensions of each layer of the multi-spectral stealth skin of the present invention, wherein a is a structural schematic diagram of the low infrared emission layer, b and c are structural schematic diagrams of the microwave absorption layer, and d is a height schematic diagram of the multi-spectral stealth skin;

[0042] Figure 7 This is a test result diagram of the infrared stealth performance of the environment-adaptive multi-spectrum compatible stealth skin system of the present invention;

[0043] Figure 8 The simulation results and experimental test results of the radar stealth performance test of the environment-adaptive multi-spectrum compatible stealth skin system of the present invention are shown;

[0044] Fig. 9 , Fig.10 This is a graph showing the angle stability test results of the radar stealth performance test of the environment-adaptive multi-spectrum compatible stealth skin system of the present invention;

[0045] Fig.11 , Fig.12 This is a graph showing the environmental mimicry performance test results of the environment-adaptive multi-spectrum compatible stealth skin system of the present invention in grassland and desert environments. DETAILED DESCRIPTION

[0046] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0047] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0048] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0049] The present invention provides a multi-spectral stealth skin, which includes a low-infrared emission layer, a microwave absorption layer and a heating layer connected in sequence from top to bottom. The microwave absorption layer includes a visible light stealth layer, and the visible light stealth layer is an environmental mimicry film prepared by an injection molding process of thermochromic capsules and polydimethylsiloxane.

[0050] As a preferred solution, the thermochromic capsules include composite materials formed by combining one or more materials of two-stage color-changing, multi-stage color-changing, colorless-to-colored or colored-to-colorless temperature-changing capsules at different temperatures.

[0051] As a preferred solution, the thermochromic capsule is a thermochromic capsule that changes from grass green to khaki at 31°C.

[0052] As a preferred solution, the microwave absorption layer includes a first microwave loss layer, a second base layer 305, an environmental mimic film 306, a first foam medium layer 307, a second microwave loss layer 308, a third base layer 309, a second foam medium layer 310, a third microwave loss layer 311, a fourth base layer 312, and a third foam medium layer 313, which are connected in sequence from top to bottom.

[0053] As a preferred solution, the first foam medium layer 307, the second foam medium layer 310, and the third foam medium layer 313 are made of polymethacrylimide, expandable polyethylene, or a composite material of polymethacrylimide and expandable polyethylene; the second base layer 305, the third base layer 309, and the fourth base layer 312 are PET bases, and the air medium layer 303 is obtained by laser engraving on the surface of the first base layer 302.

[0054] As a preferred solution, the material of the first microwave loss layer 304, the second microwave loss layer 308 and the third microwave loss layer 311 is one of indium tin oxide, antimony tin oxide and aluminum-doped zinc oxide, or a composite material of indium tin oxide, antimony tin oxide and aluminum-doped zinc oxide; the sheet resistance of the first microwave loss layer 304 and the second microwave loss layer 308 is 220-280Ω / sq; the sheet resistance of the third microwave loss layer 311 is 120-180Ω / sq.

[0055] As a preferred solution, the low infrared emission layer includes an infrared wave intercepting layer 301, a first substrate layer 302, and an air dielectric layer 303 which are sequentially connected from top to bottom. The infrared wave intercepting layer 301 is made of one of indium tin oxide, antimony tin oxide, aluminum-doped zinc oxide, and a composite material. The square resistance of the infrared wave intercepting layer 301 is 5-12Ω / sq. The first substrate layer 302 is a PET substrate.

[0056] As a preferred solution, the infrared wave intercepting layer 301 is fixed on the first substrate layer 302 by photolithography and dry etching; the first microwave loss layer 304, the second microwave loss layer 308 and the third microwave loss layer 311 are respectively fixed on the second substrate layer 305, the third substrate layer 309 and the fourth substrate layer 312 by laser etching.

[0057] As a preferred solution, the heating layer 314 is one of a graphene heating plate, a silicone heating plate and a ceramic heating plate, or a composite heating plate of graphene, silicone and ceramic.

[0058] As a preferred solution, the method for preparing the environmental mimicry film includes:

[0059] S1. The polydimethylsiloxane and SE1700 curing agent were stirred in a mass ratio of 10:1 to form a glue, and then the glue and the thermochromic capsule were mixed in a mass ratio range of 5:1 to 10:1;

[0060] S2. Place the mixture in S1 in an internal vacuum machine, and then evacuate the vacuum degree of the vacuum chamber to less than 3.0×10-3Pa, and let it stand for 30 minutes;

[0061] S3. The vacuum chamber is restored to normal pressure and the mixture is taken out, and then the mixture is poured into the coaxial method mold and the simulated film mold, respectively, and then the mold is placed in an oven at 80°C for 2h;

[0062] S4. The mold is taken out and demoulded to obtain the environmental mimicry film 306.

[0063] The present invention also provides a multi-spectral stealth skin adaptive camouflage system, the adaptive camouflage system comprises: an environment recognition unit, a control system unit and the multi-spectral stealth skin;

[0064] The environment recognition unit 1 is connected to the control system unit 2, and is used to collect the environment background image and convert it into an electrical signal and input it into the control system unit 2;

[0065] The control system unit 2 is connected to the multi-spectral stealth skin 3 , and is used to receive and analyze the electrical signal output by the environment recognition unit 1 , and convert the electrical signal into a control information source of the multi-spectral stealth skin 3 and input it into the multi-spectral stealth skin 3 .

[0066] As a preferred solution, the working process of the adaptive camouflage system includes:

[0067] Visible light stealth: The background information is obtained through the environment recognition unit 1, and then the background information is converted into an electrical signal and input into the control system unit 2. The temperature of the heating layer 314 of the multi-spectral stealth skin 3 is changed by the control system unit, and then the environmental mimicry film 306 is fitted with a color similar to the background, thereby realizing environmental mimicry, that is, visible light stealth;

[0068] Radar stealth: Each microwave loss layer in the microwave absorption layer of the multi-spectral stealth skin 3 converts microwaves into heat by means of resonance absorption and dielectric loss, thereby suppressing the reflection of microwaves and making it impossible for radar to detect, thereby achieving radar stealth;

[0069] Infrared stealth: The low infrared emissive layer blocks the emission of internal infrared waves and the absorption of external infrared waves, thereby avoiding the detection of the target by infrared detectors.

[0070] The present invention is further developed in combination with the above technical solution of the present invention as follows:

[0071] Embodiment 1:

[0072] This embodiment provides a multi-spectral stealth skin and an adaptive camouflage system thereof. The multi-spectral stealth skin 3 specifically includes:

[0073] The multi-spectral stealth skin 3 uses a periodic array indium tin oxide film with a square resistance of 8.5Ω / sq as the infrared wave interception layer 301 and an air dielectric layer 303 at its bottom as the low infrared emission layer; a square indium tin oxide film with a square resistance of 150Ω / sq is used as the first microwave loss layer 304, the second microwave loss layer 308, and a square indium tin oxide film with a square resistance of 250Ω / sq is used as the third microwave loss layer 311 and is bonded to the first foam dielectric layer 307, the second foam dielectric layer 310, and the third foam dielectric layer 313 as a microwave absorption layer, and the foam material is polymethacrylimide; a thermochromic capsule that can change from grass green to khaki at 31°C and an environmental mimic film 306 prepared by an injection molding process of polydimethylsiloxane are used as a visible light stealth layer; a silicone rubber heating plate is used as a heating layer 314, as shown in the attached Figure 2 As shown, the infrared wave intercepting layer 301 is prepared on the first substrate layer 302 by using a photolithography process and a dry etching process; the first microwave loss layer 304, the second microwave loss layer 308 and the third microwave loss layer 311 are fixed on the second substrate layer 305, the third substrate layer 309 and the fourth substrate layer 312 respectively by using a laser etching process; the multi-spectral stealth skin in the present invention is assembled by preparing each layer structure separately, and then bonding each prepared film layer to the adjacent functional layer by a high-transmittance adhesive.

[0074] The thickness of the air medium layer 303 is 1.25 mm; the thickness of the foam medium layer 307, the foam medium layer 310, and the foam medium layer 313 is 2.5 mm;

[0075] The indium tin oxide film is deposited on a substrate with a thickness of 0.125 mm by magnetron sputtering. The substrate material is selected to include a first substrate layer 302 , a second substrate layer 305 , a third substrate layer 309 , and a fourth substrate layer 312 .

[0076] In the above-mentioned multi-spectral stealth skin 3, the preparation process of the environmental mimicry film 306 includes:

[0077] S1. The polydimethylsiloxane polydimethylsiloxane and SE1700 curing agent were stirred in a mass ratio of 10:1 to form a glue, and then the glue and the thermochromic capsule were mixed in a mass ratio of 10:1;

[0078] S2. Place the mixture in S1 in an internal vacuum machine, and then evacuate the vacuum degree of the vacuum chamber to <3.0×10-3Pa, and let it stand for 30 minutes;

[0079] S3. The vacuum chamber is restored to normal pressure and the mixture is taken out, and then the mixture is poured into the coaxial method mold and the simulated film mold, respectively, and then the mold is placed in an oven at 80°C for 2h;

[0080] S4. After the mold is taken out and demoulded, the electromagnetic parameters of the coaxial method sample are tested using a vector network analyzer. The measured electromagnetic parameters are as shown in the attached Figure 3 As shown;

[0081] This embodiment also provides an adaptive camouflage system, the adaptive camouflage system includes the multi-spectrum stealth skin 3, and the environment adaptive multi-spectrum compatible stealth skin system includes:

[0082] For environmental recognition units Figure 1 In 11, the CMOS camera model selected is Daheng MER2-503-36U3C. By calling the software development kit provided by the camera manufacturer and using Python to write the camera class, the function call of the camera is completed.

[0083] For the control system unit 22, the Linux development board selects the ASUS tinker board 2s model. The workflow is as shown in the attached Figure 4 As shown:

[0084] First, the modules used in the work are initialized and materialized, including the initialization of the serial port and the materialization of the camera class; then the exposure and gain and other parameters of the camera are set; after completing the initialization of each module, the video stream is opened to obtain the current image, and a "0-1" logic matrix is ​​obtained after the adaptive camouflage pattern generation algorithm is processed. After the matrix is ​​divided and reorganized, it is sent from the serial port to the FPGA control circuit in the format of a byte stream to complete the driving of the multi-spectral stealth skin 33.

[0085] The adaptive camouflage pattern generation algorithm process is summarized as follows:

[0086] 1) Calculate the visual complexity of the background image and obtain its complexity coefficient value to represent the richness of the details (i.e., high-frequency parts) contained in the current image;

[0087] 2) According to the complexity coefficient value, the Gaussian blur parameter is dynamically selected to perform adaptive blurring on the background image; 3) For the blurred image, the K-means clustering algorithm is used to perform patch segmentation and color replacement on the image to generate a camouflage pattern. The algorithm flow framework is shown in the attached figure. Figure 5 shown.

[0088] For the multi-spectral stealth skin 33, infrared stealth is achieved by the low infrared emission layer blocking the emission of internal infrared waves and the absorption of external infrared waves, thereby avoiding the detection of the target by infrared detectors. For radar stealth, microwaves are converted into heat by the three microwave loss layers in the middle through resonance absorption, dielectric loss, etc., thereby suppressing the reflection of microwaves and making them undetectable by radar, thereby achieving radar stealth.

[0089] Visible light stealth first relies on the environmental recognition unit Figure 1 11 obtains background information, and then changes the temperature of the silicone rubber heating plate 314 through the control system unit 22, and finally fits the color close to the background by the environmental mimicry film 306, thereby realizing environmental mimicry, that is, visible light invisibility.

[0090] Embodiment 2:

[0091] Embodiment 2 is similar to Embodiment 1, except that the material selection of the multi-spectral stealth skin 3 is different, specifically including:

[0092] The multi-spectral stealth skin 3 uses a periodic array tin antimony oxide film with a square resistance of 5Ω / sq as the infrared wave interception layer 301 and an air dielectric layer 303 at its bottom as the low infrared emission layer; a block tin antimony oxide film with a square resistance of 120Ω / sq is used as the first microwave loss layer 304, the second microwave loss layer 308, and a block tin antimony oxide film with a square resistance of 220Ω / sq is used as the third microwave loss layer 311 and is bonded to the first foam dielectric layer 307, the second foam dielectric layer 310, and the third foam dielectric layer 313 as a microwave absorption layer, and the foam material is expandable polyethylene; a thermochromic capsule that can change from grass green to khaki at 31°C is selected and polydimethylsiloxane is used. The environmental mimicry film 306 prepared by the injection molding process is used as the visible light stealth layer; the graphene heating plate is selected as the heating layer 314, and the infrared wave interception layer 301 is prepared on the first substrate layer 302 by photolithography and dry etching; the first microwave loss layer 304, the second microwave loss layer 308 and the third microwave loss layer 311 are respectively fixed on the second substrate layer 305, the third substrate layer 309 and the fourth substrate layer 312 by laser etching process; the multi-spectral stealth skin in the present invention is prepared by preparing each layer structure separately, and then bonding each prepared film layer to the adjacent functional layer by a high-transmittance adhesive to complete the assembly of the skin.

[0093] The thickness of the air medium layer 303 is 0.5-2 mm; the thickness of the foam medium layer 307, the foam medium layer 310, and the foam medium layer 313 is 1 mm;

[0094] The antimony tin oxide film is deposited on a substrate with a thickness of 0.125 mm by magnetron sputtering. The substrate material is selected to include a first substrate layer 302 , a second substrate layer 305 , a third substrate layer 309 , and a fourth substrate layer 312 .

[0095] In the above-mentioned multi-spectral stealth skin 3, the preparation process of the environmental mimicry film 306 includes:

[0096] S1. The polydimethylsiloxane polydimethylsiloxane and SE1700 curing agent were stirred in a mass ratio of 10:1 to form a glue, and then the glue and the thermochromic capsule were mixed in a mass ratio of 5:1;

[0097] S2. Place the mixture in S1 in an internal vacuum machine, and then evacuate the vacuum degree of the vacuum chamber to <3.0×10-3Pa, and let it stand for 30 minutes;

[0098] S3. The vacuum chamber is restored to normal pressure and the mixture is taken out, and then the mixture is poured into the coaxial method mold and the simulated film mold, respectively, and then the mold is placed in an oven at 80°C for 2h;

[0099] S4. Take out the mold and demould it.

[0100] Embodiment 3:

[0101] Embodiment 2 is similar to Embodiment 1, except that the material selection of the multi-spectral stealth skin 3 is different, specifically including:

[0102] The multi-spectral stealth skin 3 uses a periodic array aluminum-doped zinc oxide film with a square resistance of 12Ω / sq as an infrared wave interception layer 301 and an air dielectric layer 303 at its bottom as a low infrared emission layer; a square antimony tin oxide film with a square resistance of 180Ω / sq is used as the first microwave loss layer 304, the second microwave loss layer 308, and a square aluminum-doped zinc oxide film with a square resistance of 280Ω / sq is used as the third microwave loss layer 311, which is bonded to the first foam dielectric layer 307, the second foam dielectric layer 310, and the third foam dielectric layer 313 as a microwave absorption layer, and the foam material is expandable polyethylene; thermochromic capsules that can change from grass green to khaki at 31°C are selected and polydimethylsiloxane is used. The environmental mimicry film 306 prepared by the injection molding process of methylsiloxane is used as the visible light stealth layer; a ceramic heating plate is selected as the heating layer 314, and the infrared wave interception layer 301 is prepared on the first substrate layer 302 by photolithography and dry etching processes; the first microwave loss layer 304, the second microwave loss layer 308 and the third microwave loss layer 311 are respectively fixed on the second substrate layer 305, the third substrate layer 309 and the fourth substrate layer 312 by laser etching process; the multi-spectral stealth skin in the present invention is prepared by preparing each layer structure separately, and then bonding each prepared film layer to the adjacent functional layer by a high-transmittance adhesive to complete the assembly of the skin.

[0103] The thickness of the air medium layer 303 is 2 mm; the thickness of the foam medium layer 307, the foam medium layer 310, and the foam medium layer 313 is 4 mm;

[0104] The aluminum-doped zinc oxide film is deposited on a substrate with a thickness of 0.125 mm by magnetron sputtering. The substrate material is selected to include a first substrate layer 302 , a second substrate layer 305 , a third substrate layer 309 , and a fourth substrate layer 312 .

[0105] In the above-mentioned multi-spectral stealth skin 3, the preparation process of the environmental mimicry film 306 includes:

[0106] S1. The polydimethylsiloxane polydimethylsiloxane and SE1700 curing agent were stirred in a mass ratio of 10:1 to form a glue, and then the glue and the thermochromic capsule were mixed in a mass ratio of 10:1;

[0107] S2. Place the mixture in S1 in an internal vacuum machine, and then evacuate the vacuum degree of the vacuum chamber to <3.0×10-3Pa, and let it stand for 30 minutes;

[0108] S3. The vacuum chamber is restored to normal pressure and the mixture is taken out, and then the mixture is poured into the coaxial method mold and the simulated film mold, respectively, and then the mold is placed in an oven at 80°C for 2h;

[0109] S4. Take out the mold and demould it.

[0110] The multi-spectral stealth skin 3 prepared in the above-mentioned embodiment 1 of the present invention is subjected to performance testing, specifically including:

[0111] Infrared stealth performance test (infrared emissivity):

[0112] Kirchhoff's law shows that under equilibrium conditions, the emissivity is equal to the absorptivity. Therefore, the infrared emissivity is calculated by measuring the transmission and reflection spectra of the skin using a Fourier infrared spectrometer (Bruker INVENIO-S). The experimental test results are shown in the attached Figure 7 As shown, in the infrared band of 3-14μm, the average emissivity is 0.227.

[0113] Radar stealth performance test (reflection coefficient, angle stability):

[0114] The microwave absorption characteristics of the sample were measured in a microwave anechoic chamber using an AV3655 stealth target radar cross section tester, and two pairs of broadband horn antennas with operating frequencies of 2-18 GHz and 18-40 GHz were used for measurement. Figure 8 As shown in the figure, in the radar band of 2.53-34.56GHz, the reflection coefficient is less than -10dB, which means that the microwave absorption rate exceeds 90%. The angle stability is measured using the arch method, and the angle stability of ±45° and ±60° can be maintained under TE and TM polarization respectively. The results are shown in the attached figure. Fig. 9 , Fig.10 shown.

[0115] Visible light stealth performance test (environmental mimicry performance):

[0116] The multi-spectral compatible stealth skin system was placed in grassland and desert environments for environmental mimicry performance testing. After the color change stabilized, the mimicry conditions in the two environments were as shown in the attached figure. Fig.11 and Fig.12 As shown, it can be observed that the system has a good mimicry effect.

[0117] Through the above embodiments, it is further proved that the present invention provides a multi-spectral stealth skin 3 and an environment-adaptive multi-spectral compatible stealth skin system, which can achieve a low infrared emissivity of 0.227, broadband microwave absorption (>90%) in the range of 2.53-34.56GHz and adaptive visible light stealth in grassland, desert and other environments, and has multi-spectral adaptive stealth capability. Compared with the Chinese patent CN117471404A in the background technology, it discloses an adaptive camouflage skin electronic and adaptive stealth system, but the design idea of ​​the invention is to place the adaptive color-changing layer at the bottom, which limits the infrared-radar stealth performance to a certain extent, and its infrared emissivity is higher than 0.227 of the present invention, and the absorption effect is not strong at the low frequency band of 2-10GHz. In terms of the construction of the adaptive system, the ambient light sensor used for background recognition can only transmit back single color data, and is powerless in the face of complex color environments, while the CMOS camera used in the present invention can directly transmit back the complete color information of the background image, so it has the potential for pixel-level visible light stealth and has strong adaptability.

[0118] In the description of the embodiments of the present application, it should be noted that in the description of the present application, terms such as "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description, and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present application.

[0119] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0120] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A multi-spectral stealth skin, characterized in that: The multi-spectral stealth skin (3) comprises a low infrared emission layer, a microwave absorption layer and a heating layer (314) connected in sequence from top to bottom, wherein the microwave absorption layer comprises a visible light stealth layer, and the visible light stealth layer is an environmental mimicry film (306) prepared by an injection molding process using thermochromic capsules and polydimethylsiloxane.

2. The multi-spectral stealth skin according to claim 1, characterized in that: The microwave absorption layer comprises, connected in sequence from top to bottom, a first microwave loss layer (304), a second base layer (305), an environmental mimic film (306), a first foam medium layer (307), a second microwave loss layer (308), a third base layer (309), a second foam medium layer (310), a third microwave loss layer (311), a fourth base layer (312), and a third foam medium layer (313).

3. The multi-spectral stealth skin according to claim 2, characterized in that: The first foam medium layer (307), the second foam medium layer (310), and the third foam medium layer (313) are made of polymethacrylimide, expandable polyethylene, or a composite material of polymethacrylimide and expandable polyethylene; the second base layer (305), the third base layer (309), and the fourth base layer (312) are PET bases.

4. The multi-spectral stealth skin according to claim 3, characterized in that: The material of the first microwave loss layer (304), the second microwave loss layer (308) and the third microwave loss layer (311) is one of indium tin oxide, antimony tin oxide and aluminum-doped zinc oxide, or a composite material of indium tin oxide, antimony tin oxide and aluminum-doped zinc oxide; The sheet resistance of the first microwave loss layer (304) and the second microwave loss layer (308) is 220-280Ω / sq; The sheet resistance of the third microwave loss layer (311) is 120-180Ω / sq.

5. The multi-spectral stealth skin according to claim 2, characterized in that: The low infrared emission layer comprises an infrared wave intercepting layer (301), a first substrate layer (302), and an air medium layer (303) which are sequentially connected from top to bottom; the infrared wave intercepting layer (301) is made of one of indium tin oxide, antimony tin oxide, and aluminum-doped zinc oxide, and a composite material; the sheet resistance of the infrared wave intercepting layer (301) is 5-12Ω / sq; the first substrate layer (302) is a PET substrate, and the air medium layer (303) is obtained by laser engraving on the surface of the first substrate layer (302).

6. The multi-spectral stealth skin according to claim 5, characterized in that: The infrared wave intercepting layer (301) is fixed on the first base layer (302) by means of a photolithography process and a dry etching method; the first microwave loss layer (304), the second microwave loss layer (308) and the third microwave loss layer (311) are respectively fixed on the second base layer (305), the third base layer (309) and the fourth base layer (312) by means of a laser etching process.

7. The multi-spectral stealth skin according to claim 1, characterized in that: The heating layer (314) is one of a graphene heating plate, a silica gel heating plate and a ceramic heating plate, or a composite material heating plate of graphene, silica gel and ceramic.

8. The multi-spectral stealth skin according to claim 1, characterized in that: The method for preparing the environmental mimicry film comprises: S1. The polydimethylsiloxane and SE1700 curing agent were stirred in a mass ratio of 10:1 to form a glue, and then the glue and the thermochromic capsule were mixed in a mass ratio range of 5:1 to 10:1; S2. Place the mixture in S1 in an internal vacuum machine, and then evacuate the vacuum degree of the vacuum chamber to less than 3.0×10-3Pa, and let it stand for 30 minutes; S3. The vacuum chamber is restored to normal pressure and the mixture is taken out, and then the mixture is poured into the coaxial method mold and the simulated film mold, respectively, and then the mold is placed in an oven at 80°C for 2h; S4. The mold is taken out and demoulded to obtain an environmental mimicking film (306).

9. A multi-spectral stealth skin adaptive camouflage system, characterized in that: The adaptive camouflage system comprises: an environment recognition unit (1), a control system unit (2) and a multi-spectral stealth skin (3) as claimed in any one of claims 1 to 8; The environment recognition unit (1) is connected to the control system unit (2) and is used to collect an environment background image and convert it into an electrical signal for input into the control system unit (2); The control system unit (2) is connected to the multi-spectral stealth skin (3) and is used to receive the electrical signal output by the environment recognition unit and perform analysis and processing, and convert the electrical signal into a control information source of the multi-spectral stealth skin (3) and input it into the multi-spectral stealth skin (3).

10. The multi-spectral stealth skin adaptive camouflage system according to claim 9, characterized in that: The working process of the adaptive camouflage system includes: Visible light stealth: background information is obtained through the environment recognition unit (1), and then the background information is converted into an electrical signal and input into the control system unit (2). The temperature of the heating layer (314) of the multi-spectral stealth skin (3) is changed through the control system unit (2), and then the environmental mimicry film (306) is fitted with a color close to the background, thereby achieving environmental mimicry, that is, visible light stealth; Radar stealth: each microwave loss layer in the microwave absorption layer of the multi-spectral stealth skin (3) converts microwaves into heat by means of resonance absorption and dielectric loss, thereby suppressing microwave reflection and making it impossible for radar to detect, thereby achieving radar stealth; Infrared stealth: The low infrared emissive layer blocks the emission of internal infrared waves and the absorption of external infrared waves, thereby avoiding the detection of the target by infrared detectors.

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