A dynamic radio frequency regulation method and system for unmanned aerial vehicles

Abstract

The application discloses a kind of unmanned aerial vehicle dynamic radio frequency regulation and control method and system, comprising: if current external environment radio frequency environment state is judged as no threat, and no communication demand, generate first phase encoding matrix, issue to the voltage current drive module of super surface skin, so that super surface skin generates non-periodic, pseudo-random phase distribution;Wherein super surface skin covers on unmanned aerial vehicle carrier surface;If current external environment is judged to exist at least one threat radar, to the specific incoming wave direction and specific frequency of threat radar, generate second phase encoding matrix, if current external environment radio frequency environment state is judged as no threat, and there is communication demand, to the target communication frequency band of target communication radar, detection position, select a continuous area as antenna array from super surface intelligent skin, to the detection position of target communication radar, generate third phase encoding matrix.The application can combine unmanned aerial vehicle stealth and communication.

Description

Technical Field

[0001] This application relates to the field of aircraft radar stealth technology, and in particular to a dynamic radio frequency control method and system for unmanned aerial vehicles. Background Technology

[0002] In modern high-intensity combat environments, radar is the primary detection method threatening the survival of aircraft; every reduction in radar cross-section (RCS)... The enemy's detection range can be shortened by approximately Stealth directly determines whether an aircraft can penetrate air defense systems and complete reconnaissance or strike missions. Therefore, stealth has become an irreplaceable technology for aircraft to improve their penetration probability, extend mission life, and reduce escort resources.

[0003] In existing technologies, aircraft stealth is generally achieved through the following methods:

[0004] (1) The radar cross section is reduced by special shape design and coating with radar absorbing material. However, the radar cross section (RCS) reduction effect is fixed and cannot cope with radar waves of different frequency bands and different azimuth angles; at the same time, the absorbing material is thick and heavy, which increases the load and has a shielding effect on the performance of communication antennas; and it cannot dynamically switch between the two requirements of "stealth" and "communication".

[0005] (2) It receives incident radar waves and emits electromagnetic waves with opposite amplitudes and canceling phases. However, the system is complex, consumes a lot of power, and is only effective for radars with known frequencies. It is ineffective for wideband or frequency-agile radars and may even expose itself by emitting signals.

[0006] (3) Frequency hopping, spread spectrum, and low-power communication are adopted. Disadvantages: While reducing the probability of interception only from the signal processing level, the metal structure and antenna of the UAV platform itself are still significant sources of radar scattering, and antenna radiation during communication further increases the risk of exposure.

[0007] Therefore, there is an urgent need for an integrated solution that can combine the physical concealment of a platform with its communication behavior and can dynamically and intelligently adjust according to the external electromagnetic environment. Summary of the Invention

[0008] Based on this, and in response to the aforementioned technical problems, a dynamic radio frequency control method and system for unmanned aerial vehicles (UAVs) are provided to solve the problem that existing technologies cannot combine the physical feature stealth of the platform with communication behavior, and at the same time cannot achieve precise physical feature stealth in all external environments.

[0009] A first aspect includes a dynamic radio frequency control method for unmanned aerial vehicles (UAVs), the method comprising:

[0010] It receives radio frequency signals from the external environment detected by the radio frequency sensing and reconnaissance module, determines whether there are threatening radars in the current external radio frequency environment, and determines the current communication needs of the UAV itself.

[0011] If it is determined that there is no threat to radar in the current external environment and no communication requirement, a first phase encoding matrix is ​​generated and sent to the programmable metasurface skin, so that the programmable metasurface skin generates a non-periodic, pseudo-random phase distribution to scatter the incident electromagnetic wave to multiple directions; wherein the programmable metasurface skin covers the surface of the UAV carrier; the programmable metasurface skin includes multiple metasurface units arranged in an array.

[0012] If it is determined that there is at least one threat radar in the current external environment, a second phase coding matrix is ​​generated for the specific incoming wave direction and specific frequency of the threat radar, and sent to the programmable metasurface skin, so that the scattering cross-section of the programmable metasurface skin for the specific frequency incident wave emitted by the threat radar in the incoming wave direction of the threat radar is lower than a first preset value.

[0013] If it is determined that the current external radio frequency environment is not threatening and there is a communication requirement, a continuous area is selected from the programmable metasurface skin as an antenna array for the target communication radar's target communication frequency band and detection position. The detection position is calculated for the target communication radar, a third phase coding matrix is ​​generated, and sent to the antenna array, so that the antenna array forms a directional radiation beam pointing towards the target communication radar. The main lobe width of the directional radiation beam is lower than a second preset value, and the radiation intensity in the non-target direction is reduced to below a third preset value.

[0014] Optionally, in the above scheme, the step of receiving the external environmental radio frequency signals detected by the radio frequency sensing and reconnaissance module and determining whether there is a threatening radar in the current external environmental radio frequency environment includes:

[0015] Extract the carrier frequency, pulse width, pulse repetition interval, and modulation pattern of the external environmental radio frequency signal;

[0016] The extracted parameters are compared with the pre-stored threat radar feature database;

[0017] If the comparison result exceeds the preset similarity threshold, it is determined that there is a threatening radar.

[0018] Optionally, in the above scheme, selecting a continuous region from the programmable metasurface skin as the antenna array includes:

[0019] Based on the azimuth information of the target communication radar, calculate the angle between the surface normal vector of each region of the metasurface skin and the communication direction;

[0020] The continuous region with the smallest included angle is selected and used as the antenna array.

[0021] Optionally, in the above scheme, generating the first phase encoding matrix includes:

[0022] The phase encoding values ​​between adjacent metasurface units are set to meet a preset phase difference range;

[0023] The phase difference range is configured to make the phase relationship of adjacent units appear aperiodic, so as to disrupt the wavefront continuity of the incident plane wave and scatter the energy to multiple directions.

[0024] In the above scheme, optionally, the step of generating a second phase coding matrix for the specific incoming wave direction and specific frequency of the threat radar when it is determined that at least one threat radar exists in the current external environment specifically includes:

[0025] The second phase coding matrix is ​​configured to form destructive interference in the direction of arrival of the threat radar to reduce the backscattering intensity in that direction, so that the scattering cross-section is lower than the first preset value;

[0026] Alternatively, the second phase coding matrix may be configured to deflect the energy of the incident electromagnetic wave to a preset safe direction; wherein the safe direction is configured to be spatially separated from the direction of arrival of the threat radar, and the separation angle is greater than the main lobe width of the threat radar receiving antenna, so that the scattered energy in the direction of arrival of the threat radar is lower than the first preset value.

[0027] In the above scheme, optionally, the first preset value corresponds to the minimum detectable signal power of the threat radar.

[0028] In the above scheme, optionally, the second preset value is: the 3dB beamwidth of the beam is in the range of 5 degrees to 10 degrees;

[0029] The third preset value is: the sidelobe level is at least 20 dB lower than the main lobe peak value.

[0030] Secondly, a dynamic radio frequency control system for unmanned aerial vehicles (UAVs), the system comprising:

[0031] Detection module: Used to receive external environmental radio frequency signals detected by the radio frequency sensing and reconnaissance module, and to determine whether there are threatening radars in the current external environmental radio frequency environment; and to determine the current communication needs of the UAV itself;

[0032] Normal broadband RCS reduction module: If it is determined that there is no threatening radar in the current external environment and no communication requirement, it generates a first phase encoding matrix and sends it to the programmable metasurface skin, so that the programmable metasurface skin generates a non-periodic, pseudo-random phase distribution to scatter the incident electromagnetic wave to multiple directions; wherein the programmable metasurface skin covers the surface of the UAV carrier; the programmable metasurface skin includes multiple metasurface units arranged in an array;

[0033] Specific threat directional stealth module: If it is determined that there is at least one threat radar in the current external environment, it generates a second phase coding matrix for the specific incoming wave direction and specific frequency of the threat radar, and sends it to the programmable metasurface skin, so that the programmable metasurface skin has a scattering cross-section of the specific frequency incident wave emitted by the threat radar in the incoming wave direction of the threat radar that is lower than a first preset value.

[0034] On-demand directional covert communication module: When it is determined that there is no threat to the current external radio frequency environment and there is a communication need, it selects a continuous area from the programmable metasurface skin as an antenna array for the target communication radar's target communication frequency band and detection position. It calculates the detection position for the target communication radar, generates a third phase coding matrix, and sends it to the antenna array, so that the antenna array forms a directional radiation beam pointing towards the target communication radar. The main lobe width of the directional radiation beam is lower than a second preset value, and the radiation intensity in the non-target direction is reduced to below a third preset value.

[0035] Thirdly, a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the UAV dynamic radio frequency control method described in the first aspect.

[0036] Fourthly, a computer program product includes a computer program / instructions that, when executed by a processor, implement the steps of the UAV dynamic radio frequency control method described in the first aspect.

[0037] This application has at least the following beneficial effects:

[0038] This application combines a programmable metasurface with intelligent control to achieve dynamic integration of stealth and communication functions of an unmanned aerial vehicle (UAV) platform on the same physical hardware. By sensing the external electromagnetic environment in real time, if there is no threatening radar and no communication requirement, the applied current and voltage of the programmable metasurface are controlled to generate a non-periodic, pseudo-random phase distribution on the metasurface skin. This causes the UAV to appear as a weak, flickering clutter point on the radar screen, making it difficult to track stably. If a threatening radar is present, a second phase encoding matrix is ​​generated, causing the metasurface to exhibit near-perfect absorption or scattering of electromagnetic waves of frequency t from the threatening radar in the direction of incoming waves. This achieves "directional stealth" against the most threatening radar, greatly reducing the probability of being locked on. If communication is required, the controller selects a region of the metasurface and encodes its units to work collaboratively, forming a region capable of operating in the communication frequency band. The reconfigurable patch antenna array, based on the known or real-time detection position of the target communication radar, forms a beam pointing in that direction through phase encoding of the array elements. This concentrates almost all communication signal energy within a narrow beam, resulting in extremely low radiation energy (sidelobes) in other directions. It is extremely difficult for the enemy to detect an effective signal in non-targeting directions, minimizing the risk of exposure during communication. Therefore, this application enables the UAV platform to switch between stealth and communication functions, while simultaneously achieving stealth in various external environments. Attached Figure Description

[0039] Figure 1 This application provides a schematic flowchart of a dynamic radio frequency control method for unmanned aerial vehicles (UAVs) according to one embodiment.

[0040] Figure 2 A schematic diagram of the metasurface skin coverage area provided in one embodiment of this application;

[0041] Figure 3 This is a schematic diagram illustrating the structure and working principle of a programmable metasurface unit according to an embodiment of this application;

[0042] Figure 4 A connection structure diagram of the controller and other modules provided in one embodiment of this application;

[0043] Figure 5 This is a detailed flowchart illustrating a dynamic radio frequency control method for unmanned aerial vehicles (UAVs) according to one embodiment of this application. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0045] In one embodiment, such as Figure 1 and Figure 5 As shown, a dynamic radio frequency control method for unmanned aerial vehicles (UAVs) is provided, the method comprising:

[0046] Step S1: Receive the external environment radio frequency signals detected by the radio frequency sensing and reconnaissance module, and determine whether there are threatening radars in the current external environment radio frequency environment; and determine the current communication needs of the UAV itself.

[0047] In step S1, the radio frequency sensing and reconnaissance module is integrated into the wideband detection unit in the skin, which is capable of detecting the direction of arrival, frequency, power and modulation characteristics of radar signals in a passive detection environment.

[0048] Step S2: If it is determined that there is no threatening radar in the current external environment and no communication requirement, a first phase encoding matrix is ​​generated and sent to the programmable metasurface skin, so that the programmable metasurface skin generates a non-periodic, pseudo-random phase distribution to scatter the incident electromagnetic wave to multiple directions; wherein the programmable metasurface skin covers the surface of the UAV carrier; the programmable metasurface skin includes multiple metasurface units arranged in an array.

[0049] In step S2, the metasurface skin is composed of a large number (e.g., thousands) of subwavelength-scale metasurface units arranged on a flexible substrate, which can conform to the curved surface of the UAV. Each unit integrates an adjustable element (e.g., PIN diode, varactor diode, MEMS switch), which can independently and rapidly (microsecond level) change its reflected phase and amplitude of incident electromagnetic waves by applying a bias voltage.

[0050] like Figure 2 As shown, apart from the radar-transparent nose cone and tail nozzle, most of the wings and fuselage of the drone are covered with smart skin. Figure 3 The diagram shown illustrates the structure and working principle of a programmable metasurface unit, demonstrating how it alters the electromagnetic response through bias voltage.

[0051] When the external environment is posing no threat and there is no communication requirement, this system achieves wide-bandwidth, wide-angle RCS reduction for unknown radar waves that may originate from any direction. The controller drives the metasurface to generate a non-periodic, pseudo-random phase distribution. This causes the incident plane wave to be scattered into countless weak beams pointing in random directions, preventing strong specular reflection or corner reflector effects and significantly reducing the echo intensity of the monostatic radar. This makes the UAV appear as a weak, flickering clutter point on the radar screen, making it difficult to track stably.

[0052] Step S3: If it is determined that there is at least one threat radar in the current external environment, a second phase coding matrix is ​​generated for the specific incoming wave direction and specific frequency of the threat radar, and sent to the programmable metasurface skin, so that the scattering cross-section of the programmable metasurface skin for the specific frequency incident wave emitted by the threat radar in the incoming wave direction of the threat radar is lower than a first preset value.

[0053] In step S3, if the radio frequency sensing module locks onto one or more high-priority threat radar signals (such as fire control radar), the direction of arrival is determined by estimating the direction of arrival using the phase difference of the received signals from multiple units.

[0054] Intelligent coding: The controller bases its code on the frequency of threat signals. and direction A special encoding matrix is ​​quickly solved and loaded. This matrix enables the metasurface to... Direction relative to frequency Electromagnetic waves exhibit near-perfect absorption or scattering in a harmless direction.

[0055] Dynamic tracking: As the UAV moves relative to the radar, the coding matrix is ​​updated in real time, always keeping the radar main lobe direction in the "electromagnetic black hole".

[0056] Effect: Achieves "directional stealth" against the most threatening radar, greatly reducing the probability of being locked on.

[0057] Step S4: If it is determined that there is no threat to the current external radio frequency environment and there is a communication requirement, select a continuous area from the programmable metasurface skin as an antenna array for the target communication radar's target communication frequency band and detection position. Calculate the detection position for the target communication radar, generate a third phase coding matrix, and send it to the antenna array so that the antenna array forms a directional radiation beam pointing towards the target communication radar. The main lobe width of the directional radiation beam is lower than a second preset value, and the radiation intensity in non-target directions is reduced to below a third preset value.

[0058] In step S4, when the system switches to communication mode, the module connects to a metasurface whose specific area is reconstructed as an antenna for signal modulation and demodulation. The controller selects a metasurface area and encodes its units to work together, forming a region capable of operating in the communication frequency band. A reconfigurable patch antenna array. Beamforming: based on the known or real-time detected positions of friendly nodes. By phase encoding the array elements, low-intercept communication is formed in that direction: almost all the communication signal energy is concentrated within a narrow beam, with extremely low radiation energy (sidelobes) in other directions. It is extremely difficult for the enemy to detect an effective signal in non-targeting directions. Rapid switching: communication is conducted in a burst manner; after each communication, the metasurface in that area quickly reverts to stealth mode encoding. This enables "pinpoint" communication, minimizing the risk of exposure during the communication process itself.

[0059] In this embodiment, such as Figure 4 The diagram shows the connection structure between the controller and other modules. The controller has a built-in high-performance processor and a pre-built "electromagnetic strategy library". The controller can receive data from the sensing module, combine it with the UAV's own state (attitude, mission phase), and calculate and generate an "encoding matrix" in real time to drive the bias voltage of each unit of the metasurface.

[0060] This application includes the following steps:

[0061] (1) Infiltration Phase (Stealth in Normal Mode): The UAV flies to the mission area. The central controller is loaded with "Wideband RCS Reduction Mode" encoding by default, which drives the metasurface to generate a non-periodic, pseudo-random phase distribution. At this time, the echo signals received by both enemy long-range early warning radar and low-altitude blind spot radar are very weak and unstable.

[0062] (2) Upon approaching the target area, the radio frequency sensing module detects a fire control radar scanning signal from the 10 o'clock direction at the X-band frequency. The controller immediately switches to "Specific Threat Directional Stealth Mode". Within milliseconds, the metasurface re-encodes the X-band signal and the 10 o'clock direction. On the fire control radar operator's screen, the previously faint target echo suddenly disappears (absorbed / scattered elsewhere), making it impossible to lock on.

[0063] (3) Reconnaissance and Data Transmission (Covered Communication): The UAV arrives at the reconnaissance position and acquires images using its optical payload. The data needs to be transmitted back to a ground station 50 kilometers away. The controller activates the "on-demand directional covert communication mode." A metasurface located on the fuselage is reconfigured as a phased array antenna operating in the Ku-band. Based on pre-set ground station coordinates and the UAV's own navigation information, the beam pointing angle is precisely calculated. The communication system then "precisely injects" encrypted data to the ground station via an extremely narrow beam at a high speed and in a short burst. The entire process lasts only a few hundred milliseconds.

[0064] (4) Withdrawal and mode recovery; After communication is completed, the fuselage supersurface recovers the stealth code, the UAV returns along the original route, and the system continues to respond to possible threat radars.

[0065] In the aforementioned dynamic radio frequency control method for unmanned aerial vehicles (UAVs), the combination of a programmable metasurface and intelligent control achieves dynamic integration of stealth and communication functions on the same physical hardware. By sensing the external electromagnetic environment in real time, if there is no threatening radar and no communication requirement, the applied current and voltage of the programmable metasurface are controlled to generate a non-periodic, pseudo-random phase distribution on the metasurface skin. This causes the UAV to appear as a weak, flickering clutter point on the radar screen, making it difficult to track stably. If a threatening radar is present, a second phase encoding matrix is ​​generated, causing the metasurface to exhibit near-perfect absorption or scattering of electromagnetic waves at frequency t of the threatening radar in the direction of incoming waves, achieving "directional stealth" against the most threatening radar and greatly reducing the probability of being locked on. If communication is required, the controller selects a region of the metasurface and encodes its units to work collaboratively, forming a region capable of operating in the communication frequency band. The reconfigurable patch antenna array, based on the known or real-time detection position of the target communication radar, forms a beam pointing in that direction through phase encoding of the array elements. This concentrates almost all communication signal energy within a narrow beam, resulting in extremely low radiation energy (sidelobes) in other directions. It is extremely difficult for the enemy to detect an effective signal in non-targeting directions, minimizing the risk of exposure during communication. Therefore, this application enables the UAV platform to switch between stealth and communication functions, while simultaneously achieving stealth in various external environments.

[0066] In one embodiment, receiving radio frequency signals from the external environment detected by the radio frequency sensing and reconnaissance module and determining whether there is a threatening radar in the current external radio frequency environment includes:

[0067] Extract the carrier frequency, pulse width, pulse repetition interval, and modulation pattern of the external environmental radio frequency signal;

[0068] The extracted parameters are compared with the pre-stored threat radar feature database;

[0069] If the comparison result exceeds the preset similarity threshold, it is determined that there is a threatening radar.

[0070] In one embodiment, selecting a continuous region from the programmable metasurface skin as an antenna array includes:

[0071] Based on the azimuth information of the target communication radar, calculate the angle between the surface normal vector of each region of the metasurface skin and the communication direction;

[0072] The continuous region with the smallest included angle is selected and used as the antenna array.

[0073] In one embodiment, generating the first phase encoding matrix includes:

[0074] The phase encoding values ​​between adjacent metasurface units are set to meet a preset phase difference range;

[0075] The phase difference range is configured to make the phase relationship of adjacent units appear aperiodic, so as to disrupt the wavefront continuity of the incident plane wave and scatter the energy to multiple directions.

[0076] In one embodiment, if it is determined that at least one threatening radar exists in the current external environment, generating a second phase coding matrix for the specific direction of arrival and specific frequency of the threatening radar specifically includes:

[0077] The second phase coding matrix is ​​configured to form destructive interference in the direction of arrival of the threat radar to reduce the backscattering intensity in that direction, so that the scattering cross-section is lower than the first preset value;

[0078] Alternatively, the second phase coding matrix may be configured to deflect the energy of the incident electromagnetic wave to a preset safe direction; wherein the safe direction is configured to be spatially separated from the direction of arrival of the threat radar, and the separation angle is greater than the main lobe width of the threat radar receiving antenna, so that the scattered energy in the direction of arrival of the threat radar is lower than the first preset value.

[0079] In one embodiment, the first preset value corresponds to the minimum detectable signal power of the threat radar.

[0080] In one embodiment, the second preset value is: the 3dB beamwidth of the beam is in the range of 5 to 10 degrees;

[0081] The third preset value is: the sidelobe level is at least 20 dB lower than the main lobe peak value.

[0082] This application modifies the shell or key parts of a drone into a smart skin, enabling it to perceive external threat radar signals in real time and dynamically reconstruct the surface electromagnetic properties to achieve optimal stealth. Simultaneously, when communication is needed, it can instantly convert a local metasurface into a high-performance directional antenna, enabling covert communication with friendly nodes using an extremely narrow beam and low sidelobes, achieving "detection equals stealth, communication equals directionality."

[0083] The beneficial effects of this application include:

[0084] 1. Integrated Design: For the first time, the platform's stealth and communication antenna functions are achieved through the same physical layer (metasurface), solving the inherent problem of mutual constraints between traditional stealth and communication antennas.

[0085] 2. Dynamic intelligent adaptive stealth has evolved from "fixed stealth" to intelligent dynamic stealth of "perception-decision-response", which can effectively cope with complex and changing electromagnetic threat environments.

[0086] 3. Dual concealment at the physical and signal layers: It not only achieves low observability in terms of physical scattering characteristics, but also low probability interception in terms of the radiation characteristics of communication, providing double protection.

[0087] 4. Lightweight and conformal design: The metasurface skin is thin and flexible, hardly changing the aerodynamic shape of the UAV and not significantly increasing the load.

[0088] 5. Expandable functionality: The same hardware platform can be redefined through software, allowing for future expansion to include new functions such as electromagnetic interference and wireless power reception.

[0089] In one embodiment, this application further includes the following:

[0090] 1. Distributed cooperative variant: In multi-machine formations, the metasurfaces of each machine can work together, treating the formation as a whole as a "distributed metasurface", and generating more complex electromagnetic deception effects (such as simulating false targets) through cooperative coding.

[0091] 2. Machine Learning Optimization Variation: The "electromagnetic strategy library" of the central controller can be optimized online using reinforcement learning algorithms. Through continuous interaction with the electromagnetic environment, it can autonomously learn the optimal stealth and communication coding strategies.

[0092] 3. Multifunctional Fusion Variation: In communication mode, the beamforming capability of metasurfaces can be further utilized to simultaneously perform blind zone listening or implement precise micro-interference on non-cooperative signal sources.

[0093] 4. In the civilian field, the adaptive spectrum sharing variant can be used to enable UAVs to intelligently "bypass" occupied communication frequency bands in complex spectrum environments and select "spectrum holes" for communication to avoid interference.

[0094] 5. Low-power wake-up variant: During long-term latent tasks, most units of the system can be in a power-off sleep state, with only a few sensing units on duty. Full power startup is only initiated when a specific wake-up signal (such as a friendly laser-coded signal) is detected.

[0095] In one embodiment, a dynamic radio frequency control system for unmanned aerial vehicles (UAVs) is also provided, the system comprising:

[0096] Detection module: Used to receive external environmental radio frequency signals detected by the radio frequency sensing and reconnaissance module, and to determine whether there are threatening radars in the current external environmental radio frequency environment; and to determine the current communication needs of the UAV itself;

[0097] Normal broadband RCS reduction module: If it is determined that there is no threatening radar in the current external environment and no communication requirement, it generates a first phase encoding matrix and sends it to the programmable metasurface skin, so that the programmable metasurface skin generates a non-periodic, pseudo-random phase distribution to scatter the incident electromagnetic wave to multiple directions; wherein the programmable metasurface skin covers the surface of the UAV carrier; the programmable metasurface skin includes multiple metasurface units arranged in an array;

[0098] Specific threat directional stealth module: If it is determined that there is at least one threat radar in the current external environment, it generates a second phase coding matrix for the specific incoming wave direction and specific frequency of the threat radar, and sends it to the programmable metasurface skin, so that the programmable metasurface skin has a scattering cross-section of the specific frequency incident wave emitted by the threat radar in the incoming wave direction of the threat radar that is lower than a first preset value.

[0099] On-demand directional covert communication module: When it is determined that there is no threat to the current external radio frequency environment and there is a communication need, it selects a continuous area from the programmable metasurface skin as an antenna array for the target communication radar's target communication frequency band and detection position. It calculates the detection position for the target communication radar, generates a third phase coding matrix, and sends it to the antenna array, so that the antenna array forms a directional radiation beam pointing towards the target communication radar. The main lobe width of the directional radiation beam is lower than a second preset value, and the radiation intensity in the non-target direction is reduced to below a third preset value.

[0100] For specific limitations regarding a dynamic radio frequency control system for unmanned aerial vehicles (UAVs), please refer to the limitations of a dynamic radio frequency control method for UAVs mentioned above, which will not be repeated here. Each module in the aforementioned dynamic radio frequency control system for UAVs can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0101] In one embodiment, a computer device is provided, which may be a terminal. The computer device includes a processor, memory, a communication interface, a display screen, and an input device connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The communication interface is used for wired or wireless communication with an external terminal; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. When the computer program is executed by the processor, it implements the aforementioned dynamic radio frequency control method for unmanned aerial vehicles. The display screen may be an LCD screen or an e-ink screen. The input device may be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0102] In one embodiment, a computer-readable storage medium is also provided, on which a computer program is stored relating to all or part of the processes in the methods of the above embodiments.

[0103] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0104] In one embodiment, a computer program product is also provided, including a computer program / instructions, characterized in that, when the computer program / instructions are executed by a processor, they involve all or part of the processes in the methods of the above embodiments.

[0105] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0106] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for dynamic radio frequency control of unmanned aerial vehicles (UAVs), characterized in that, The method includes: It receives radio frequency signals from the external environment detected by the radio frequency sensing and reconnaissance module, determines whether there are threatening radars in the current external radio frequency environment, and determines the current communication needs of the UAV itself. If it is determined that there is no threat to radar in the current external environment and no communication requirement, a first phase encoding matrix is ​​generated and sent to the programmable metasurface skin, so that the programmable metasurface skin generates a non-periodic, pseudo-random phase distribution to scatter the incident electromagnetic wave to multiple directions; wherein the programmable metasurface skin covers the surface of the UAV carrier; the programmable metasurface skin includes multiple metasurface units arranged in an array. If it is determined that there is at least one threat radar in the current external environment, a second phase coding matrix is ​​generated for the specific incoming wave direction and specific frequency of the threat radar, and sent to the programmable metasurface skin, so that the scattering cross-section of the programmable metasurface skin for the specific frequency incident wave emitted by the threat radar in the incoming wave direction of the threat radar is lower than a first preset value. If it is determined that the current external radio frequency environment is not threatening and there is a communication requirement, a continuous area is selected from the programmable metasurface skin as an antenna array for the target communication radar's target communication frequency band and detection position. The detection position is calculated for the target communication radar, a third phase coding matrix is ​​generated, and sent to the antenna array, so that the antenna array forms a directional radiation beam pointing towards the target communication radar. The main lobe width of the directional radiation beam is lower than a second preset value, and the radiation intensity in the non-target direction is reduced to below a third preset value.

2. The dynamic radio frequency control method for unmanned aerial vehicles according to claim 1, characterized in that, The receiving radio frequency sensing and reconnaissance module detects external environmental radio frequency signals and determines whether there is a threatening radar in the current external environmental radio frequency environment, including: Extract the carrier frequency, pulse width, pulse repetition interval, and modulation pattern of the external environmental radio frequency signal; The extracted parameters are compared with the pre-stored threat radar feature database; If the comparison result exceeds the preset similarity threshold, it is determined that there is a threatening radar.

3. The dynamic radio frequency control method for unmanned aerial vehicles according to claim 1, characterized in that, Selecting a continuous region from the programmable metasurface skin as an antenna array includes: Based on the azimuth information of the target communication radar, calculate the angle between the surface normal vector of each region of the metasurface skin and the communication direction; The continuous region with the smallest included angle is selected and used as the antenna array.

4. The dynamic radio frequency control method for unmanned aerial vehicles according to claim 1, characterized in that, The generation of the first phase encoding matrix includes: The phase encoding values ​​between adjacent metasurface units are set to meet a preset phase difference range; The phase difference range is configured to make the phase relationship of adjacent units appear aperiodic, so as to disrupt the wavefront continuity of the incident plane wave and scatter the energy to multiple directions.

5. The dynamic radio frequency control method for unmanned aerial vehicles according to claim 1, characterized in that, If it is determined that at least one threatening radar exists in the current external environment, generating a second phase coding matrix for the specific incoming wave direction and specific frequency of the threatening radar specifically includes: The second phase coding matrix is ​​configured to form destructive interference in the direction of arrival of the threat radar to reduce the backscattering intensity in that direction, so that the scattering cross-section is lower than the first preset value; Alternatively, the second phase coding matrix may be configured to deflect the energy of the incident electromagnetic wave to a preset safe direction; wherein the safe direction is configured to be spatially separated from the direction of arrival of the threat radar, and the separation angle is greater than the main lobe width of the threat radar receiving antenna, so that the scattered energy in the direction of arrival of the threat radar is lower than the first preset value.

6. The dynamic radio frequency control method for unmanned aerial vehicles according to claim 5, characterized in that, The first preset value corresponds to the minimum detectable signal power of the threat radar.

7. The dynamic radio frequency control method for unmanned aerial vehicles according to claim 1, characterized in that, The second preset value is: the 3dB beamwidth of the beam is in the range of 5 to 10 degrees; The third preset value is: the sidelobe level is at least 20 dB lower than the main lobe peak value.

8. A dynamic radio frequency control system for unmanned aerial vehicles (UAVs), characterized in that, The system includes: Detection module: Used to receive external environmental radio frequency signals detected by the radio frequency sensing and reconnaissance module, and to determine whether there are threatening radars in the current external environmental radio frequency environment; and to determine the current communication needs of the UAV itself; Normal broadband RCS reduction module: If it is determined that there is no threatening radar in the current external environment and no communication requirement, it generates a first phase encoding matrix and sends it to the programmable metasurface skin, so that the programmable metasurface skin generates a non-periodic, pseudo-random phase distribution to scatter the incident electromagnetic wave to multiple directions; wherein the programmable metasurface skin covers the surface of the UAV carrier; the programmable metasurface skin includes multiple metasurface units arranged in an array; Specific threat directional stealth module: If it is determined that there is at least one threat radar in the current external environment, it generates a second phase coding matrix for the specific incoming wave direction and specific frequency of the threat radar, and sends it to the programmable metasurface skin, so that the programmable metasurface skin has a scattering cross-section of the specific frequency incident wave emitted by the threat radar in the incoming wave direction of the threat radar that is lower than a first preset value. On-demand directional covert communication module: When it is determined that there is no threat to the current external radio frequency environment and there is a communication need, it selects a continuous area from the programmable metasurface skin as an antenna array for the target communication radar's target communication frequency band and detection position. It calculates the detection position for the target communication radar, generates a third phase coding matrix, and sends it to the antenna array, so that the antenna array forms a directional radiation beam pointing towards the target communication radar. The main lobe width of the directional radiation beam is lower than a second preset value, and the radiation intensity in the non-target direction is reduced to below a third preset value.

9. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the method as described in any one of claims 1 to 7.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the method described in any one of claims 1 to 7.

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