Electromagnetic stealth system with embedded optical fiber sensor and regulation and control method

Abstract

The invention discloses an electromagnetic stealth system embedded with optical fiber sensing and a regulation and control method. The problem that in the prior art, detection of electromagnetic wave frequency and stealth metasurface deformation cannot be cooperatively monitored and regulated and controlled is mainly solved. The system comprises a wave-transparent layer, a stealth layer, a control circuit layer, a supporting structure layer, a photoelectric field detector and a sensing layer paved with an optical fiber strain sensor, wherein the optical fiber strain sensor is bent and laid between the wave-transparent layer and the sensing layer to form an integral structure; according to strain information collected by an optical fiber strain sensor, position coordinates of each meta-surface unit after deformation are reconstructed, in combination with frequency information detected by a photoelectric field detector and the calculated position coordinates, a coding matrix of the whole system after regulation and control is calculated in real time, corresponding voltage signals are obtained through conversion according to the matrix, and regulation and control are completed. The method overcomes the difficulty that the deformation of the metasurface cannot be monitored, can regulate and control the deteriorated stealth performance after the deformation of the system structure in real time, and effectively improves the system performance.

Description

Technical Field

[0001] This invention belongs to the field of electronics and further relates to electromagnetic metasurface technology, specifically an electromagnetic cloaking system and control method embedded with fiber optic sensors. By using embedded fiber optic sensors to monitor the frequency of the probe wave and the deformation of the system structure in real time, high-performance electromagnetic cloaking is achieved through real-time scattering control of the probe wave. Background Art

[0002] Electromagnetic metasurfaces are a widely used stealth electromagnetic functional structure. Reflective electromagnetic metasurfaces can achieve electromagnetic stealth by scattering the opponent's detection waves in other directions. To achieve stealth, electromagnetic metasurfaces need to detect the frequency of external detection waves to adjust the operating frequency of the metasurface. Moreover, due to aerodynamics, vibration, and impact, the electromagnetic metasurface can easily deform, thereby deteriorating the stealth performance of the metasurface. In order to ensure the reliability of its system operation, it is necessary to coordinately monitor the frequency of external detection electromagnetic waves and the deformation of the stealth metasurface in real time and regulate the stealth performance. In current engineering and academic research, there is only the ability to detect the frequency of electromagnetic waves, but there is a lack of a technology for coordinated detection of frequency and metasurface deformation, and it is impossible to regulate the stealth performance of the deformed metasurface.

[0003] The patent document with patent number CN202211061541.6 and publication number CN 115411530 A discloses an electromagnetic stealth system based on an optoelectronic field sensor. The optoelectronic field sensor, which can accurately detect the time domain information of the incident electromagnetic wave in real time, detects the frequency of the incident electromagnetic wave in real time. The frequency information of the incident wave is used to control the bias voltage corresponding to the PIN diode through an algorithm, so that the reflected beam is scattered in a specified direction to achieve electromagnetic stealth. However, the system can only sense the frequency of the detection wave, and cannot sense the deformation of the system and the impact of the deformation on the stealth performance of the system, and cannot regulate the performance after deformation. In addition, in the patent document with patent number CN202310995370.2 and publication number CN117268173A, a flexible electronic object stealth system is proposed. The system uses a radar wave detection module to judge the data of the currently emitted radar detection electromagnetic microwaves, thereby starting the antenna array of the microwave energy collection module and extending the antenna array to the length of the optimal absorption degree, thereby absorbing the electromagnetic microwaves to the greatest extent, so as to achieve better stealth effect when facing different types of detection radars; although this scheme can detect electromagnetic microwave data, it is made of a flexible matrix, so it is very easy to deform, and the system cannot perceive and control its own deformation, which is greatly limited in actual engineering applications. Summary of the Invention

[0004] The purpose of the present invention is to address the deficiencies of the above-mentioned existing technologies and propose an electromagnetic stealth system and control method embedded with optical fiber sensing, aiming to collaboratively monitor the frequency of the incident detection electromagnetic wave and its deformation of the stealth electromagnetic functional structure, and to regulate the stealth performance to achieve better electromagnetic stealth effect.

[0005] To achieve the above objectives, the present invention proposes an electromagnetic stealth system embedded with optical fiber sensing, comprising a wave-transmitting layer 1, a stealth layer 3, a control circuit layer 4, a support structure layer 5, an optical field detector 7, and a sensing layer 2 on which an optical fiber strain sensor 6 is laid;

[0006] The optical fiber strain sensor 6 is bent in an S-shape and laid between the wave-transmitting layer 1 and the sensing layer 2 and solidified together into an integral structure;

[0007] The stealth layer 3 is used to scatter the incident detection wave to achieve stealth. This layer is composed of a reconfigurable reflective metasurface and is connected to the control circuit layer 4 below it through wiring. Its upper surface is tightly adhered to the lower surface of the sensing layer 2 by gluing;

[0008] The control circuit layer 4 is used for voltage conversion;

[0009] The support structure layer 5 is provided with two grooves, one large and one small, and a connecting hole is provided in the middle of the two grooves. The stealth layer 3 and the control circuit layer 4 are placed in the large groove; the photoelectric field detector 7 is embedded in the small groove and is wiredly connected to the control circuit layer 4 through the connecting hole.

[0010] Furthermore, the wave-transmitting layer 1 and the sensing layer 2 are both made of glass fiber.

[0011] Furthermore, the control circuit layer 4 is implemented by an FPGA control board and a voltage conversion module.

[0012] At the same time, a stealth performance control method for an electromagnetic stealth system embedded with optical fiber sensing is proposed, which includes the following steps:

[0013] S1: The optical fiber strain sensor is placed in an S-bend on the sensing layer to obtain measurement data;

[0014] S2: The strain value ε∈R of each sensing point is obtained by demodulating the measured data through the optical fiber demodulator m×1 , the deformation of the metasurface is sensed according to the strain value, the position coordinates of each metasurface unit are obtained, and the full-field displacement matrix containing the displacements of m×n metasurface units is obtained by the modal method The displacement of the cell in the mth row and nth column of the matrix is ​​recorded as y mn ; y mn Decompose it into components along the mutually orthogonal x, y and z directions, and let the coordinate of the center point of the unit before deformation be xmn ,y mn ,z mn , after deformation, it becomes x' mn ,y' mn ,z' mn , get the position vector r' of the unit center mn ;

[0015] S3: The control circuit layer calculates the phase control value of each unit after deformation:

[0016] S3.1: Assume that the direction of the i-th incident wave is U i for According to the following formula, U i The distance R from the isophase surface to the element in the mth row and nth column imn and phase shift delay

[0017]

[0018] Where k = 2*π / λ is the wave number in free space, λ = c / f is the wavelength of the incident wave, c represents the speed of light, and f is the frequency of the incident electromagnetic wave;

[0019] S3.2: When the metasurface is not deformed, the encoding matrix A mn Encoding control is performed by scattering the incident wave into the scattered wave direction U r Realize electromagnetic stealth; when deformation occurs, first restore the scattered beam after deformation to U r , let U r for According to the following formula, U r The distance R from the isophase surface to the element in the mth row and nth column rmn and phase shift delay

[0020]

[0021] S3.3: The deformed beam is realized in U according to the following formula r Directional scattering:

[0022]

[0023] in, is the phase value of the unit in the mth row and nth column, expressed as follows:

[0024]

[0025] Obtain the phase value of each unit to obtain the same scattered beam direction as when it was not deformed;

[0026] S3.4: Calculate the phase control value of each unit after deformation according to the following formula:

[0027]

[0028] in is the phase value of the unit in the mth row and nth column when not deformed;

[0029] S4: Calculate the coding matrix of the metasurface after deformation control based on the phase control amount. The steps are as follows:

[0030] S4.1: Calculate the number of control bits for each unit of the metasurface:

[0031]

[0032] Among them, C mn represents the number of control bits of the unit in the mth row and nth column, and p represents the number of bits of the metasurface;

[0033] S4.2: Round off the number of control bits of each unit as the final number of control bits of the current unit, and obtain the encoding matrix T of the metasurface after deformation control according to the following formula: mn :

[0034] T mn =A mn +C mn ;

[0035] S5: The encoding matrix T of the metasurface after deformation control mn The corresponding voltage signal is obtained through the voltage conversion module to complete the regulation of the stealth performance of the system.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] First, since the present invention embeds an optical fiber strain sensor in the perception layer, it can monitor the deformation of the stealth layer metasurface in real time. The optical field sensor embedded in the system detects the frequency information of the incident wave and transmits the data to the processing unit, providing reliable data support for the regulation of the stealth metasurface, thereby overcoming the difficulty of monitoring the deformation of the metasurface in the existing technology.

[0038] Second, the method for controlling the performance of the stealth metasurface after deformation designed by the present invention calculates the deformation of the metasurface in real time based on the input strain information, and calculates the coding matrix of the deformed metasurface in combination with the frequency information of the incident wave, which can perform real-time control of the deteriorated stealth performance; the proposed control algorithm fills the gap that the existing technology cannot control the performance of the metasurface that has deteriorated after deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1Schematic diagram of the overall structure of the system in the present invention;

[0040] Figure 2 A schematic diagram of the working principle of the system in an embodiment of the present invention;

[0041] Figure 3 Flowchart for implementing the control method in an embodiment of the present invention;

[0042] Figure 4 This is the 9.2GHz reflective 2-bit metasurface 8x8 array HFSS simulation model provided by an embodiment of the present invention; (a) is the HFSS simulation model of the undeformed array, and (b) is the HFSS simulation model of the deformed array;

[0043] Figure 5 Comparison of the scattering patterns of the 9.2GHz metasurface array before deformation, after deformation, and after control provided by an embodiment of the present invention;

[0044] Figure 6 This is the RCS diagram before and after control of the 9.2GHz metasurface array disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] Example 1: Reference Figure 1 The electromagnetic stealth system embedded with optical fiber sensing proposed in the present invention includes a wave-transmitting layer 1, a stealth layer 3, a control circuit layer 4, a support structure layer 5, an optical field detector 7, and a sensing layer 2 on which an optical fiber strain sensor 6 is laid;

[0047] The optical fiber strain sensor 6 is bent in an S-shape and laid between the wave-transmitting layer 1 and the sensing layer 2 and solidified together into an integral structure;

[0048] The stealth layer 3 is used to scatter the incident detection wave to achieve stealth. This layer is composed of a reconfigurable reflective metasurface and is connected to the control circuit layer 4 below it through wiring. Its upper surface is tightly adhered to the lower surface of the sensing layer 2 by gluing;

[0049] The control circuit layer 4 is used for voltage conversion;

[0050] The support structure layer 5 is provided with two grooves, one large and one small, and a connecting hole is provided in the middle of the two grooves. The stealth layer 3 and the control circuit layer 4 are placed in the large groove; the photoelectric field detector 7 is embedded in the small groove and is wiredly connected to the control circuit layer 4 through the connecting hole.

[0051] Furthermore, the wave-transmitting layer 1 and the sensing layer 2 are both made of glass fiber.

[0052] Furthermore, the control circuit layer 4 is implemented by an FPGA control board and a voltage conversion module.

[0053] Furthermore, the wave-transmitting layer 1, the sensing layer 2 and the supporting structure 5 are provided with fixing holes 8 at the same position, and rivets are used through the fixing holes 8 to connect all structures to the object to be invisible during assembly.

[0054] Example 2: Reference Figure 2 The overall structure of the electromagnetic stealth system proposed in the present invention is the same as that in Example 1. The working principle of the system of the present invention is now further described:

[0055] In this embodiment, the system of the present invention is conformally attached to the surface of the object to be invisible by bolts or other fixing methods. When the object is deformed, the optical fiber strain sensor 6 embedded in the system also deforms accordingly. Figure 3 As shown, deformation causes the measured wavelength of the optical fiber to change. The changed wavelength information is transmitted to the fiber Bragg grating demodulator, which can demodulate the strain information of each sensing point. The demodulator transmits the strain information to a computing device for encoding and processing. The device includes a computer and an FPGA module. The computer is configured with the control algorithm proposed by the present invention, which is used to reconstruct the coordinate position of each unit of the stealth metasurface after deformation based on the demodulated strain value and calculate the deformed coding matrix based on the detected incident wave frequency. The calculated coding matrix is ​​then sent to the FPGA controller located in the control circuit layer 4. The coding matrix is ​​converted into control voltage information using its own decoding module and voltage conversion module. The demodulator can also transmit the strain information directly to the control circuit layer, and the FPGA controller built into the control circuit layer performs encoding and decoding operations, and then converts it into control voltage information. Finally, the voltage information is loaded into the active device on the metasurface unit located in the stealth layer 3 through the control line to change its operating state. Each metasurface switches to a different operating state according to the coding rule, scattering the incident detection electromagnetic wave in other directions, thereby reducing the radar cross section (RCS) value of the system and realizing the control of the electromagnetic stealth performance after deformation.

[0056] Example 3: Reference Figure 3 The present invention proposes a method for controlling the stealth performance of an electromagnetic stealth system embedded with optical fiber sensing, which specifically includes the following steps:

[0057] Step S1: Arrange the optical fiber strain sensors in an S-bend on the sensing layer to obtain measurement data. In this embodiment, the specific number of optical fiber strain sensors arranged on the sensing layer in this step is determined according to the actual size of the system to ensure that sufficient measurement data is obtained.

[0058] Step S2: Demodulate the measured data using a fiber demodulator to obtain the strain value ε∈R of each sensing pointm ×1 , the deformation of the metasurface is sensed according to the strain value, the position coordinates of each metasurface unit are obtained, and the full-field displacement matrix containing the displacements of m×n metasurface units is obtained by the modal method The displacement of the cell in the mth row and nth column of the matrix is ​​recorded as y mn ; y mn Decompose it into components along the mutually orthogonal x, y and z directions, and let the coordinate of the center point of the unit before deformation be x mn ,y mn ,z mn , after deformation, it becomes x' mn ,y' mn ,z' mn , get the position vector r' of the unit center mn ; The displacement y of the unit in the mth row and nth column in this embodiment is mn , specifically expressed as follows:

[0059]

[0060] in, represents the displacement modal matrix, represents the strain mode shape matrix, Represents the pseudoinverse of a matrix.

[0061] The position vector r' of the center point of the unit in the mth row and nth column above mn , specifically expressed as follows:

[0062]

[0063] Step S3: The control circuit layer calculates the phase control value of each unit after deformation:

[0064] S3.1: Assume that the direction of the i-th incident wave is U i for According to the following formula, U i The distance R from the isophase surface to the element in the mth row and nth column imn and phase shift delay

[0065]

[0066]

[0067] Wherein, k=2*π / λ is the wave number in free space, λ=c / f is the wavelength of the incident wave, c represents the speed of light, and f is the frequency of the incident electromagnetic wave, which is acquired in real time by the optical field sensor (7).

[0068] S3.2: When the metasurface is not deformed, the encoding matrix Amn Encoding control is performed by scattering the incident wave into the scattered wave direction U r Realize electromagnetic stealth; when deformation occurs, first restore the scattered beam after deformation to U r , let U r for According to the following formula, U r The distance R from the isophase surface to the element in the mth row and nth column rmn and phase shift delay

[0069]

[0070] S3.3: The deformed beam is realized in U according to the following formula r Directional scattering:

[0071]

[0072] in, is the phase value of the unit in the mth row and nth column, expressed as follows:

[0073]

[0074] Obtain the phase value of each unit to obtain the same scattered beam direction as when it was not deformed;

[0075] S3.4: Calculate the phase control value of each unit after deformation according to the following formula:

[0076]

[0077] in is the phase value of the unit in the mth row and nth column when not deformed;

[0078] In this embodiment, the phase control value of each unit after the above deformation, its strain and the coupling formula of the control value of each unit of the metasurface are as follows:

[0079]

[0080] Where k is the beam.

[0081] Step S4: Calculate the coding matrix of the metasurface after deformation control according to the phase control amount. The steps are as follows:

[0082] S4.1: Calculate the number of control bits for each unit of the metasurface:

[0083]

[0084] Among them, C mn represents the number of control bits of the unit in the mth row and nth column, and p represents the number of bits of the metasurface;

[0085] In this embodiment, the higher the number of the above-mentioned final control bits is, the higher the control accuracy of the metasurface is, that is, the better the control effect of the electromagnetic stealth is.

[0086] S4.2: Round off the number of control bits of each unit as the final number of control bits of the current unit, and obtain the encoding matrix T of the metasurface after deformation control according to the following formula: mn :

[0087] T mn =A mn +C mn ;

[0088] Step S5: The control circuit layer adjusts the encoding matrix T of the metasurface according to the deformation mn The corresponding voltage signal is obtained through the voltage conversion module to complete the regulation of the stealth performance of the system.

[0089] Example 4: The overall implementation steps of the control method proposed in this example are the same as those in Example 3. Figure 3 The implementation process of the method of the present invention is further described in detail with specific examples:

[0090] Step 1: Arrange fiber grating sensors

[0091] like Figure 1 As shown, the optical fiber strain sensor is arranged in an S-shaped broken line on the sensing layer, and multiple sensors are set according to the size of the system to obtain more measurement data.

[0092] Step 2: Collect optical fiber strain sensor data

[0093] The outlet of the embedded optical fiber strain sensor is connected to a fiber Bragg grating (FBG) interrogator, which is then connected to a computer. The measured strain data is then transmitted to a host computer. The computer described in this step in this embodiment is an external computing device, but the data can also be directly transmitted to the control circuit layer consisting of an FPGA control board and voltage conversion module, with the FPGA performing data processing. This embodiment uses data processing on an external host computer as an example.

[0094] Step 3: Collect photoelectric field sensor data

[0095] The optical fiber outlet of the photoelectric field sensor inside the system is connected to the photoelectric field measurement host, and the measurement host is connected to the computer to transmit the measured incident electromagnetic wave frequency to the host computer.

[0096] Step 4: Reconstruct the position coordinates of each metasurface unit on the stealth layer

[0097] Under the action of external force, the metasurface will deform, and the schematic diagram before and after the deformation is as follows Figure 3As shown in (a) and (b), the optical fiber strain sensors arranged in the system are used to sense this deformation and obtain the strain value ε∈R at each sensing point. m×1 , the deformation of the metasurface is sensed according to the measured strain to obtain the position coordinates of each metasurface unit, and the full-field displacement virtual perception equation is obtained by the modal method:

[0098]

[0099] Where, represents the displacement modal matrix, represents the strain mode shape, Represents the pseudoinverse of a matrix. and It needs to be obtained through measured data and finite element simulation data. Represents the full-field displacement matrix, which contains m×n displacement vectors, corresponding to the displacement of m×n metasurface units, and the displacement y of the unit in the mth row and nth column mn , specifically expressed as follows:

[0100]

[0101] y mn Decomposed into components along the mutually orthogonal x, y, and z directions:

[0102]

[0103] Before deformation, the coordinates of the center points of the unit in the mth row and nth column are x mn ,y mn ,z mn , then the unit coordinate after deformation is x ' mn ,y ' mn ,z ' mn , the position vector of each point in the unit center is expressed as:

[0104]

[0105] Step 5: Calculate the phase adjustment of each unit after deformation

[0106] Assume that the incident wave U i Direction according to Figure 3 In the rectangular coordinate system shown, the distance from the incident wave to the phase plane to the unit is:

[0107]

[0108] Then the phase shift delay from the isophase surface of the incident wave to the unit is:

[0109]

[0110] Among them, k = 2*π / λ is the wave number in free space, λ = c / f is the wavelength of the incident wave, c represents the speed of light, and f is the frequency of the incident electromagnetic wave, which can be obtained through the optical field sensor.

[0111] Assume that the main beam U r Direction The distance from the center of the array element to the spatial equiphase surface

[0112]

[0113] Then the phase shift delay from the unit on the reflective programmable metasurface to the spatial equiphase surface is:

[0114]

[0115] After the metasurface is deformed, the distance between each metasurface unit and the phase plane such as the incident direction and the scattered main beam direction changes, resulting in a change in the incident phase and reflection phase of each reflective unit after deformation compared to the undeformed state. Compensating for this change can restore the metasurface performance to the undeformed state. The distance between the detection electromagnetic wave emitted by the other party and each unit on the metasurface is different, resulting in a different spatial incident phase for each reflective unit on the array. In order to achieve the beam in the U r Directional scattering, after the illumination phase of each unit on the surface is adjusted to the incident wave, it should be in U r The isophase surface is formed with the vertical direction, which is expressed as follows:

[0116]

[0117] Depend on <6> 、 <7> 、 <9> The calculation formula for the phase value of each array element is:

[0118]

[0119] From the formula <10> It can be deduced that, given the incident wave frequency f and the incident wave direction U i , scattered beam direction U r and the geometric center r' of the deformed metasurface element mn , the phase of each element in the array can be calculated to obtain the specified scattered beam direction.

[0120] After deformation, the phase control value of each unit is

[0121]

[0122] in is the phase value of the element when it is not deformed.

[0123] The coupling formula between strain and each unit control quantity of the metasurface is:

[0124]

[0125] Where k is the beam, U i is the incident wave direction, U r is the scattered beam direction, x mn ,y mn ,z mn are the center coordinates of the undeformed elements, represents the displacement modal matrix, represents the strain mode shape matrix, ε represents the strain value measured by the strain sensor, is the phase value of the undeformed element.

[0126] Step 6: Calculate the metasurface coding matrix based on the phase control amount

[0127] The number of control bits for each unit of the metasurface is:

[0128]

[0129] Where p represents the number of bits of the metasurface, for example, p = 2 for a 2-bit metasurface. Due to the limitation of the control accuracy of the metasurface, the calculated C mn Rounding is performed, so the higher the number of bits, the higher the control accuracy of the metasurface, and the better the control of the stealth effect.

[0130] The encoding matrix of the metasurface is calculated according to the following formula:

[0131] T mn =A mn +C mn <14>

[0132] Where T mn is the encoding matrix of the metasurface after deformation control, A mn is the encoding matrix before deformation.

[0133] The method of the present invention reconstructs the position coordinates of each metasurface unit after deformation through an algorithm based on the strain information collected by the optical fiber strain sensor, and combines the frequency information detected by the photoelectric field detector and the calculated position coordinates to calculate the coding matrix of the entire system after regulation in real time, thereby effectively regulating the stealth performance that deteriorates after deformation.

[0134] The effects of the present invention will be further described below in conjunction with simulation experiments.

[0135] 1. Simulation conditions:

[0136] The present invention is carried out in the hardware environment of INTEL XEON(R) GOLD 6558Q CPU and NVDIA GeForce RTX4090 GPU and Windows Sever 2019 Datacenter as the operating system software.

[0137] 2. Simulation content:

[0138] The present invention uses a 2-bit metasurface operating at 9.2 GHz and uses HFSS2023 software to establish an HFSS simulation model of the stealth layer. Figure 4 As shown, (a) and (b) are the simulation models of the 8x8 array without deformation and deformation, respectively.

[0139] 3. Simulation results:

[0140] The simulation results are as follows Figure 5 and 6 As shown, Figure 5 The scattering patterns of the metasurface array before deformation, after deformation, and after control are simulated. It can be seen that the method proposed in the present invention adjusts the direction of the scattered main beam after deformation to the same direction as before deformation. Figure 6 This is the single-station RCS diagram before and after the above-mentioned metasurface simulation regulation. It can be seen that the RCS before deformation regulation at the operating frequency is -8.5dBsm, and the RCS after regulation is reduced to -14.4dBsm. After the regulation of the present invention, the RCS is reduced by about 6dB, and the RCS at frequencies near the operating frequency is also reduced. The results prove the effectiveness of the present invention.

[0141] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the laws, regulations and standards of relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0142] The above simulation analysis proves the correctness and effectiveness of the method proposed in the present invention.

[0143] Parts of the present invention that are not described in detail belong to common knowledge among those skilled in the art.

[0144] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Obviously, for professionals in this field, after understanding the content and principles of the present invention, they may make various modifications and changes in form and details without departing from the principles and structure of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. An electromagnetic stealth system embedded in optical fiber sensing, comprising a wave-transmitting layer (1), a stealth layer (3), a control circuit layer (4), a supporting structure layer (5) and an optical field detector (7), characterized in that: It also includes a sensing layer (2) on which an optical fiber strain sensor (6) is laid; The optical fiber strain sensor (6) is bent in an S-shape and laid between the wave-transmitting layer (1) and the sensing layer (2) and solidified together to form an integral structure; The stealth layer (3) is used to scatter incident detection waves to achieve stealth. The layer is composed of a reconfigurable reflective metasurface and is connected to the control circuit layer (4) below it via wiring. The upper surface of the layer is tightly adhered to the lower surface of the sensing layer (2) by gluing. The control circuit layer (4) is used for voltage conversion; The support structure layer (5) is provided with two grooves, one large and one small, and a connection hole is provided between the two grooves. The stealth layer (3) and the control circuit layer (4) are placed in the large groove; the photoelectric field detector (7) is embedded in the small groove and is wiredly connected to the control circuit layer (4) through the connection hole.

2. The system according to claim 1, wherein: The wave-transmitting layer (1) and the sensing layer (2) are both made of glass fibers.

3. The system according to claim 1, wherein: The control circuit layer (4) is implemented by an FPGA control board and a voltage conversion module.

4. A method for controlling the stealth performance of an electromagnetic stealth system embedded with optical fiber sensing, characterized in that: The steps include: S1: The optical fiber strain sensor is placed in an S-bend on the sensing layer to obtain measurement data; S2: The strain value ε∈R of each sensing point is obtained by demodulating the measured data through the optical fiber demodulator m×1 , the deformation of the metasurface is sensed according to the strain value, the position coordinates of each metasurface unit are obtained, and the full-field displacement matrix containing the displacements of m×n metasurface units is obtained by the modal method The displacement of the cell in the mth row and nth column of the matrix is ​​recorded as y mn ; y mn Decompose it into components along the mutually orthogonal x, y and z directions, and let the coordinate of the center point of the unit before deformation be x mn ,y mn ,z mn , after deformation, it becomes x' mn ,y' mn ,z' mn , get the position vector r′ of the unit center point mn ; S3: Calculate the phase control value of each unit after deformation: S3.1: Assume that the direction of the i-th incident wave is U i for According to the following formula, U i The distance R from the isophase surface to the element in the mth row and nth column imn and phase shift delay Where k = 2*π / λ is the wave number in free space, λ = c / f is the wavelength of the incident wave, c represents the speed of light, and f is the frequency of the incident electromagnetic wave; S3.2: When the metasurface is not deformed, the encoding matrix A mn Encoding control is performed by scattering the incident wave into the scattered wave direction U r Realize electromagnetic stealth; when deformation occurs, first restore the scattered beam after deformation to U r , let U r for According to the following formula, U r The distance R from the isophase surface to the element in the mth row and nth column rmn and phase shift delay S3.3: The deformed beam is realized in U according to the following formula r Directional scattering: in, is the phase value of the unit in the mth row and nth column, expressed as follows: Obtain the phase value of each unit to obtain the same scattered beam direction as when it was not deformed; S3.4: Calculate the phase control value of each unit after deformation according to the following formula: in is the phase value of the unit in the mth row and nth column when not deformed; S4: Calculate the coding matrix of the metasurface after deformation control based on the phase control amount. The steps are as follows: S4.1: Calculate the number of control bits for each unit of the metasurface: Among them, C mn represents the number of control bits of the unit in the mth row and nth column, and p represents the number of bits of the metasurface; S4.2: Round off the number of control bits of each unit as the final number of control bits of the current unit, and obtain the encoding matrix T of the metasurface after deformation control according to the following formula: mn : T mn =A mn +C mn ; S5: The encoding matrix T of the metasurface after deformation control mn The corresponding voltage signal is obtained through the voltage conversion module to complete the regulation of the stealth performance of the system.

5. The method according to claim 4, characterized in that: The specific number of the optical fiber strain sensors provided on the sensing layer in step S1 is determined according to the actual size of the system.

6. The method according to claim 4, characterized in that: The displacement y of the unit in the mth row and nth column in step S2 is mn , specifically expressed as follows: in, represents the displacement modal matrix, represents the strain mode shape matrix, Represents the pseudoinverse of a matrix.

7. The method according to claim 6, characterized in that: The position vector r' of the center point of the unit in the mth row and nth column in step S2 mn , specifically expressed as follows:

8. The method according to claim 4, wherein: The frequency f of the incident electromagnetic wave in step S3.1 is acquired in real time by the optical field sensor (7).

9. The method according to claim 7, wherein: The phase control value of each unit after deformation is calculated in step S3.

4. The coupling formula of its strain and the control value of each unit of the metasurface is as follows: Where k is the beam.

10. The method according to claim 4, characterized in that: The higher the final control bit number described in step S4.1, the higher the control accuracy of the metasurface, that is, the better the control effect of the electromagnetic stealth.

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