A method for searching and detecting unmanned aerial vehicles

Abstract

The present invention provides a method for searching and detecting unmanned aerial vehicles, which is used for searching and detecting unmanned aerial vehicles in a designated airspace. The method comprises a transmitting radar module, a receiving radar module and an analyzing module connected to the receiving radar module; the analyzing module stores characteristic data of airflow disturbance of the unmanned aerial vehicle when the unmanned aerial vehicle is flying; the transmitting radar is a transmitting radar set to transmit detection radar waves to the designated airspace, the analyzing module obtains the radar reflection beam of the designated airspace through the receiving radar module, and analyzes the airflow status data of the designated airspace from the reflection beam. When the airflow status data contains data matching the characteristic data of airflow disturbance of the unmanned aerial vehicle, it is considered that there may be unmanned aerial vehicles in a flying state in the designated airspace; the present invention can make up for the defects of traditional unmanned aerial vehicle search and accurately search and detect the flight phenomenon of unmanned aerial vehicles in the designated airspace.

Description

Technical Field

[0001] The invention relates to the field of radar detection technology, in particular to a method for searching and detecting unmanned aerial vehicles. Background Art

[0002] Since my country gradually opened up the low-altitude airspace below 1,000 meters, there have been more and more "low, slow, and small" aircraft such as drones, model airplanes, hot air balloons, and sky lanterns. While bringing convenience to economic and social development, it has also provided opportunities for criminals to take advantage of. Various illegal flights have caused serious safety hazards to important activities and key areas, and seriously disrupted the normal flight and take-off and landing of flights.

[0003] There are a large number of users who have not received professional training, who fly for personal gain, and who have no common sense or awareness of flight laws and regulations. Civilian drones weigh as little as two or three kilograms or as much as dozens of kilograms. If they fall from an altitude of tens or hundreds of meters, they may cause casualties.

[0004] Currently, the main ways to search and detect low, slow and small targets in the air include passive radio spectrum detection search and detection, traditional passive or active radar search and detection of target surfaces, acoustic wave recognition search and detection, and visible light cameras or infrared thermal imagers, etc.

[0005] Radio spectrum monitoring is to search and find drones by passively detecting the "communication" between drones and ground remote controllers, such as the spectrum signals of remote control systems, data transmission systems or image transmission systems. Radio spectrum monitoring has the characteristics of wide detection range, long distance and fast response, and is a practical and effective detection method. However, if the drone target does not emit radio signals and is in a "silent" state, it will be impossible to detect the drone using electromagnetic spectrum methods.

[0006] Traditional radar search and detection of drones is done through existing 2D / 3D mechanical or electronic scanning radar technology, which uses the phenomenon of electromagnetic waves generating reflected waves when passing through different transmission media to detect drone targets. However, modern drones are generally made of plastic foam, light wood and composite materials, which have special wave characteristics and greatly reduce the actual effect. In addition, the radar scattering area of ​​the drone itself is very small, which reduces the effective scattering area, distance and detection probability of being detected by radar.

[0007] Acoustic recognition search and detection of drones is to identify the noises emitted by drones when they are working on board. By matching the detected audio with a database that records the audio of all drones, it is possible to identify whether it is the sound of a drone. However, the current effective detection distance of this technology is short and it is very susceptible to interference.

[0008] Visible light / infrared detection uses visible light or thermal infrared reflection of the target, and uses a combination of over-the-horizon, high-definition, visible cameras and infrared thermal imager sensors to detect drones. Visible light / infrared detection can detect drones of all types and can achieve all-weather, real-time, and visual monitoring and management. However, due to the small size of drones, their infrared radiation and characteristics are low, which greatly shortens the detection distance through infrared detection. In terms of anti-laser detection, drones are more likely to use materials such as wave absorption, transmission, and light guidance to reduce laser reflection and appearance stealth design, making visible light / infrared detection more difficult. Summary of the invention

[0009] The present invention provides a method for searching and detecting drones, which can make up for the defects of traditional drone searches and accurately search and detect drone flight phenomena in a specified airspace.

[0010] The present invention adopts the following technical solutions.

[0011] A method for searching and detecting unmanned aerial vehicles is used for searching and detecting unmanned aerial vehicles in a designated airspace. The method comprises a transmitting radar module, a receiving radar module and an analyzing module connected to the receiving radar module; the analyzing module stores characteristic data of airflow disturbance of the unmanned aerial vehicle when the unmanned aerial vehicle is flying; the transmitting radar is a transmitting radar set to transmit detection radar waves to the designated airspace, the analyzing module obtains the radar reflection beam of the designated airspace through the receiving radar module, and analyzes the airflow status data of the designated airspace from the reflection beam. When the airflow status data contains data matching the characteristic data of airflow disturbance of the unmanned aerial vehicle, it is considered that there may be a flying unmanned aerial vehicle in the designated airspace.

[0012] The number of the transmitting radar modules and the receiving radar modules are configured in a one-to-one ratio or a one-to-many ratio.

[0013] The transmitting radar module or the receiving radar module is a part of a weather radar or a part of a Doppler radar.

[0014] The drone includes a fixed-wing drone, a multi-rotor drone, or a drone with both fixed-wing and multi-rotor wings.

[0015] The UAV airflow disturbance characteristic data includes vortex disturbance characteristic data generated when the UAV rotor works in the air, and also includes the UAV body wake disturbance characteristic data.

[0016] The vortex disturbance characteristic data and the body wake disturbance characteristic data are radar reflection beam characteristics caused by changes in the refractive index caused by changes in air turbulence and air density formed when the UAV is working or moving.

[0017] When the analysis module finds that the airflow condition data contains data that matches the drone airflow disturbance characteristic data, it is considered that there may be a drone in flight at the location of the drone airflow disturbance point in the specified airspace.

[0018] The transmitting radar module and the receiving radar module are high-sensitivity ultra-high frequency radar modules or very high frequency radar modules.

[0019] The transmitting radar module includes a transmitter; the receiving radar module includes a receiver, a signal processor, a data processor and a display; the transmitting radar module and the receiving radar module are both connected to the radar antenna via a duplexer; the radar antenna is connected to a beam scanning generator or a server.

[0020] The technical solution described in the present invention is designed to address the phenomenon that the atmospheric refractive index changes to varying degrees caused by the vortex generated by the rotor of a multi-rotor UAV when working in the air or the wake generated by the body of a fixed-wing UAV can scatter irregular radar beams. It is well known that the irregular changes in atmospheric refraction can produce irregular radar illumination echoes, and the irregularity of atmospheric refraction is caused by irregular changes in the temperature, humidity and density of the airflow (high-speed flow of the airflow inside the vortex or wake); when the UAV is flying, the vortex or wake flows with the high-speed movement of the airflow generated when the UAV is working in the air, and the ground radar receiving module can detect the irregular echoes scattered by the vortex or wake to search and discover the UAV; and the vortex or wake is a basic phenomenon that cannot be eliminated when the UAV is working in the air. Obtaining the irregular radar echo information of the vortex or wake provides a most direct and effective tool for radar search and discovery of the UAV.

[0021] The invention has a unique principle, ingenious conception and high feasibility. It can efficiently search and discover "low, small and slow" targets in the air and can effectively suppress the illegal and unlawful "illegal flying" of drones. The invention is not affected by the material of the drone, and because the movement of mechanical aircraft is quite different from that of flying birds, drones and flying birds can be easily distinguished. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0023] Attached Figure 1 This is a schematic diagram of the airflow disturbance generated by the drone;

[0024] Attached Figure 2 It is a working schematic diagram of the present invention;

[0025] Attached Figure 3 This is a schematic diagram of the radar components;

[0026] In the figure: 1-UAV; 2-transmitting radar module; 3-receiving radar module. DETAILED DESCRIPTION

[0027] like Figure 1-3 As shown, a method for searching and detecting drones is used to search and detect drones 1 in a designated airspace. The method includes a transmitting radar module 2, a receiving radar module 3 and an analysis module connected to the receiving radar module; the analysis module stores the drone airflow disturbance characteristic data when the drone is flying; the transmitting radar is a transmitting radar set to transmit detection radar waves to the designated airspace, the analysis module obtains the radar reflection beam of the designated airspace through the receiving radar module, and analyzes the airflow condition data of the designated airspace from the reflection beam. When the airflow condition data contains data matching the drone airflow disturbance characteristic data, it is considered that there may be a drone in flight in the designated airspace.

[0028] The number of the transmitting radar modules and the receiving radar modules are configured in a one-to-one ratio or a one-to-many ratio.

[0029] The transmitting radar module or the receiving radar module is a part of a weather radar or a part of a Doppler radar.

[0030] The drone includes a fixed-wing drone, a multi-rotor drone, or a drone with both fixed-wing and multi-rotor wings.

[0031] The UAV airflow disturbance characteristic data includes vortex disturbance characteristic data generated when the UAV rotor works in the air, and also includes the UAV body wake disturbance characteristic data.

[0032] The vortex disturbance characteristic data and the body wake disturbance characteristic data are radar reflection beam characteristics caused by changes in the refractive index caused by changes in air turbulence and air density formed when the UAV is working or moving.

[0033] When the analysis module finds that the airflow condition data contains data that matches the drone airflow disturbance characteristic data, it is considered that there may be a drone in flight at the location of the drone airflow disturbance point in the specified airspace.

[0034] The transmitting radar module and the receiving radar module are high-sensitivity ultra-high frequency radar modules or very high frequency radar modules.

[0035] The transmitting radar module includes a transmitter; the receiving radar module includes a receiver, a signal processor, a data processor and a display; the transmitting radar module and the receiving radar module are both connected to the radar antenna via a duplexer; the radar antenna is connected to a beam scanning generator or a server.

[0036] Example:

[0037] The lift of a multi-rotor drone mainly comes from the high-speed rotation of the rotor blades, which presses the air downward and uses the force of the downwash airflow obtained thereby. Therefore, vortices are generated above and below the rotors of a multi-rotor drone when it is moving or hovering due to the high-speed rotation of the blades.

[0038] The vortex generated by the rotor of a multi-rotor drone when working in the air or the atmospheric refractive index changes caused by the wake generated by the fixed-wing drone body can scatter irregular radar beams. The irregular changes in atmospheric refraction can produce irregular radar illumination echoes, and the irregularity of atmospheric refraction is caused by irregular changes in the temperature, humidity and density of the airflow (high-speed flow of air inside the vortex or wake).

[0039] The vortex or wake flows with the high-speed movement of the airflow generated when the drone is working in the air. The same beam emitted by the ground transmitting radar (transmitting radar module) reaches the vortex airflow of the multi-rotor drone. The echo reflected from the vortex airflow to the receiving radar (receiving radar module) is different. In this way, after a series of signal processing and data processing at the back end, the irregular echo scattered by the vortex or wake can be detected to search and find the drone.

[0040] Since vortices or wakes are essential phenomena that cannot be eliminated when a UAV is operating in the air, obtaining the irregular radar echo information of the vortex or wake through the solution described in the present invention provides a most direct and effective tool for radar search and detection of UAVs.

Claims

1. A method for searching and detecting drones, for searching and detecting drones in a specified airspace. Features: The method comprises a transmitting radar module, a receiving radar module and an analysis module connected to the receiving radar module; the analysis module stores characteristic data of airflow disturbance of the UAV when the UAV is flying; the transmitting radar is a transmitting radar set to transmit detection radar waves to a designated airspace, the analysis module obtains the radar reflection beam of the designated airspace through the receiving radar module, and analyzes the airflow status data of the designated airspace from the reflection beam, and when the airflow status data contains data matching the characteristic data of airflow disturbance of the UAV, it is considered that there may be a UAV in a flying state in the designated airspace; The number of the transmitting radar modules and the receiving radar modules is configured in a one-to-one ratio or a one-to-many ratio; The transmitting radar module or the receiving radar module is a part of a weather radar or a part of a Doppler radar; When the analysis module finds that the airflow condition data contains data that matches the drone airflow disturbance characteristic data, it is considered that there may be a drone in flight at the location of the drone airflow disturbance point in the specified airspace; The transmitting radar module and the receiving radar module are high-sensitivity ultra-high frequency radar modules or very high frequency radar modules; The transmitting radar module includes a transmitter; the receiving radar module includes a receiver, a signal processor, a data processor and a display; the transmitting radar module and the receiving radar module are both connected to the radar antenna via a duplexer; the radar antenna is connected to a beam scanning generator or a server; The UAV is a low, slow and small multi-rotor UAV, which generates vortices above and below the rotors when it is moving or hovering due to the high-speed rotation of the blades; the different degrees of change in the atmospheric refractive index caused by the vortex can scatter irregular radar beams and generate irregular radar illumination echoes; the vortex flows with the high-speed movement of the airflow generated when the UAV is working in the air, and the same beam emitted by the transmitting radar module on the ground reaches the vortex airflow of the multi-rotor UAV. The echoes reflected from the vortex airflow to the receiving radar module are different. The irregular echoes scattered by the vortex or wake are detected through back-end signal processing and data processing to search and discover the UAV.

2. A method for searching and detecting drones according to claim 1, Features: The drone includes a fixed-wing drone, a multi-rotor drone, or a drone with both fixed-wing and multi-rotor wings.

3. A method for searching and detecting drones according to claim 2, Features: The UAV airflow disturbance characteristic data includes vortex disturbance characteristic data generated when the UAV rotor works in the air, and also includes the UAV body wake disturbance characteristic data.

4. A method for searching and detecting drones according to claim 3, Features: The vortex disturbance characteristic data and the body wake disturbance characteristic data are radar reflection beam characteristics caused by changes in the refractive index caused by changes in air turbulence and air density formed when the UAV is working or moving.

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