Unmanned aerial vehicle false broadcast message identification method and system based on radio direction finding and positioning

Abstract

The invention discloses an unmanned aerial vehicle false broadcast message identification method and system based on radio direction finding positioning, and the method comprises the steps: an unmanned aerial vehicle periodically broadcasts a remote identification message signal according to the national standard, a radio detection station receives the message signal, marks a timestamp, and solves the incoming wave direction of the message signal; and analyzing the unique identification code and position information of the unmanned aerial vehicle in the message, classifying the observation data of the radio detection station based on the unique identification code of the unmanned aerial vehicle, sorting the observation data according to the receiving time sequence and grouping the observation data according to a certain time interval, and performing unmanned aerial vehicle cross positioning on each group of observation data in combination with the position information of the radio detection station. And finally, judgment is performed from dimensions such as distance (coverage area), angle, positioning and trajectory and a combination sequence, so that the resource overhead can be effectively reduced, and the judgment efficiency is improved. The method has the technical characteristic of identifying the false broadcast message of the unmanned aerial vehicle, and is favorable for supporting the construction of a low-altitude economic airspace target management and control system.

Description

Technical Field

[0001] The present invention relates to the technical field of low-altitude economic UAV supervision, and particularly to a method and system for identifying false broadcast messages of UAVs based on radio direction finding (DF, Direction Finding). Background Art

[0002] According to the national standard GB 42590-2023 "Safety Requirements for Civil Unmanned Aerial Vehicle Systems", during flight, light and small unmanned aerial vehicles should actively report identification information to the comprehensive supervision service platform through the network, such as automatically broadcasting identification information via wireless local area network (Wi-Fi) or Bluetooth. However, to evade supervision, some UAVs may broadcast false message information, such as forging positions or identification codes, resulting in the failure of airspace control and threatening low-altitude safety.

[0003] Currently, the identification methods for false messages mostly make judgments based on a single dimension. For example, they only rely on the matching of the parsed position and the physical distance in the message, or only judge the coverage range through the signal strength. Such methods have significant defects: the single-dimensional criterion is vulnerable to environmental interference (such as signal attenuation, multipath effects, etc.), resulting in a high false positive rate; at the same time, multi-dimensional data do not form a collaborative criterion logic, and repeated calculation resources are required, resulting in low efficiency. For example, if false messages are judged only by distance, misjudgments may occur due to radio direction finding errors or signal propagation delays; if only trajectory analysis is relied on, it is difficult to respond in real time to dynamic false signals. Summary of the Invention

[0004] To overcome the problems of low reliability of single-dimensional criteria and poor resource efficiency in the above-mentioned prior art, the present invention provides a method and system for identifying false broadcast messages of UAVs based on radio direction finding. By integrating multi-dimensional criteria such as distance coverage range, direction deviation of the incoming wave, cross-location consistency, and trajectory movement trend, the determination is performed in a logical order, first excluding obviously abnormal data, and gradually narrowing the discrimination range. This method improves the discrimination accuracy and efficiency while reducing the consumption of computing resources, effectively supporting the real-time supervision requirements of UAVs in the low-altitude economic airspace.

[0005] To achieve the above invention purpose, the following technical solutions are adopted:

[0006] A method for identifying false broadcast messages of UAVs based on radio direction finding, characterized by including the following steps:

[0007] Step S1: The UAV broadcasts a remote identification message signal periodically according to the national standard. The radio detection station receives the message signal, marks the time stamp, calculates the direction of the incoming wave of the message signal, and parses the unique identification code and position information of the UAV in the message;

[0008] Step S2: Classify the observation data of the radio detection station based on the unique identification code of the UAV, sort them in the order of receiving time, group them at a certain time interval, and perform UAV cross-positioning for each group of observation data in combination with the position information of the radio detection station, thereby forming trajectory information;

[0009] Step S3: Judge whether the UAV broadcast message is a false message according to the distance. Based on the parsed position of the UAV message, calculate the distance between the UAV and the radio detection station. If the distance between the two is greater than 3 times the coverage range of the radio detection station, it is determined that the UAV broadcast message is a false message; otherwise, proceed to Step S4 for judgment;

[0010] Step S4: Judge whether the UAV broadcast message is a false message according to the incoming wave direction. Based on the parsed position of the UAV message, calculate the theoretical incoming wave direction of the radio detection station. If the deviation between the theoretical incoming wave direction and the observed incoming wave direction of the radio detection station is greater than 3 times the angle measurement accuracy, it is determined that the UAV broadcast message is a false message; otherwise, proceed to Step S5 for judgment;

[0011] Step S5: Judge whether the UAV broadcast message is a false message according to the positioning information. If the deviation between the cross-positioning estimated position and the parsed position is greater than 3 times the positioning accuracy of the cross-positioning system, it is determined that the UAV broadcast message is a false message; otherwise, proceed to Step S6 for judgment;

[0012] Step S6: Judge whether the UAV broadcast message is a false message according to the positioning trajectory. Based on the parsed UAV message, obtain the UAV broadcast trajectory. If the movement trends of the observed trajectory and the broadcast trajectory are inconsistent, it is determined that the UAV broadcast message is a false message; otherwise, it is determined that the UAV broadcast message is a true message.

[0013] Further, the said Step S1:

[0014] The UAV broadcasts a remote identification message signal periodically according to the national standard. The message contains the unique identification code of the UAV and real-time position information;

[0015] The radio detection station has the ability of two-dimensional radio signal direction finding, and calculates the incoming wave direction of the message signal, that is, the pitch angle and the azimuth angle;

[0016] The radio detection station has the ability to parse communication protocols, and parses the unique identification code of the UAV and real-time position information in the message;

[0017] The radio detection station can mark the time stamp of the received signal.

[0018] Further, the said Step S2:

[0019] The radio detection stations are time-synchronized with each other, and the observation coordinate systems are unified;

[0020] Collect the observation data of each radio detection station in real time, and classify the observation data according to the unique identification code of the target UAV.

[0021] Sort the classified data in the order of receiving time.

[0022] Group the classified data at a certain time interval. The observation data that traces back 1 second every 0.1 second is used as a group.

[0023] Combine the position of the detection station with the observation data of each group to perform cross-positioning of the target UAV and obtain the observed position of the UAV.

[0024] Filter the observed position of the UAV to obtain the observed trajectory.

[0025] Furthermore, the radio detection stations are time-synchronized with each other. Characteristically, the radio detection stations use satellite time synchronization. Specifically, the radio detection stations use network time synchronization.

[0026] The present invention discloses a system for identifying false broadcast messages of UAVs assisted by radio direction finding and positioning, including at least one UAV, at least two radio detection stations, and at least one server, wherein:

[0027] The UAV broadcasts a remote identification message signal periodically according to national standards.

[0028] The radio detection stations use satellite time synchronization, receive the message signal and mark the timestamp, calculate the direction of arrival of the message signal, and parse the unique identification code and position information of the UAV in the message.

[0029] The server receives the observation data reported by each radio detection station, classifies the observation data of the radio detection stations based on the unique identification code of the UAV, sorts them in the order of receiving time, and groups them at a certain time interval (the observation data that traces back 1 second every 0.1 second is used as a group). The position information of the radio detection station is combined with the observation data of each group to perform cross-positioning of the UAV and filter the observed position of the UAV to obtain the observed trajectory.

[0030] Judge whether the UAV broadcast message is a false message according to the distance. Based on the parsed position of the UAV message, calculate the distance from the radio detection station. If the distance between the two is greater than 3 times the coverage range of the radio detection station, it is determined that the UAV broadcast message is a false message. Otherwise, judge whether the UAV broadcast message is a false message according to the incoming wave direction. Based on the parsed position of the UAV message, calculate the theoretical incoming wave direction of the radio detection station. If the deviation between the theoretical incoming wave direction and the incoming wave direction observed by the radio detection station is greater than 3 times the angle measurement accuracy, it is determined that the UAV broadcast message is a false message. Otherwise, judge whether the UAV broadcast message is a false message according to the positioning information. If the deviation between the cross-positioning estimated position and the parsed position is greater than 3 times the positioning accuracy of the cross-positioning system, it is determined that the UAV broadcast message is a false message. Otherwise, judge whether the UAV broadcast message is a false message according to the positioning trajectory. Based on the parsed UAV message, obtain the UAV broadcast trajectory. If the movement trends of the observed trajectory and the broadcast trajectory are inconsistent, it is determined that the UAV broadcast message is a false message. Otherwise, it is determined that the UAV broadcast message is a true message.

[0031] Due to the adoption of the above technical solutions, the present invention has the following advantages and positive effects compared with the prior art:

[0032] 1. Utilize the radio direction finding and positioning technology to receive and observe the UAV broadcast identification message signal, and jointly design a method for identifying false UAV broadcast messages assisted by radio direction finding and positioning from dimensions such as distance (coverage range), angle, positioning, and trajectory based on the observed information;

[0033] 2. Through the combined sequence determination, it can effectively reduce the resource overhead, improve the discrimination efficiency, has the technical feature of identifying false UAV broadcast messages, and is beneficial to supporting the construction of the low-altitude economic airspace target management and control system. Description of the Drawings

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings. In the drawings:

[0035] Figure 1 It is a schematic flow chart of a method for identifying false UAV broadcast messages assisted by radio direction finding and positioning according to the present invention;

[0036] Figure 2 It is a block diagram of the composition of a system for identifying false UAV broadcast messages assisted by radio direction finding and positioning according to the present invention. Detailed Embodiment

[0037] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work belong to the scope of protection of the present invention.

[0038] Embodiment 1

[0039] As Figure 1 shown, a method for identifying false broadcast messages of an unmanned aerial vehicle assisted by radio direction finding and positioning in this embodiment includes the following steps:

[0040] Step S1: The unmanned aerial vehicle broadcasts a remote identification message signal periodically according to the national standard. The radio detection station receives the message signal, marks the time stamp, calculates the direction of arrival of the message signal, and parses the unique identification code and position information of the unmanned aerial vehicle in the message.

[0041] Step S2: Based on the unique identification code of the unmanned aerial vehicle, classify the observation data of the radio detection station, sort them in the order of receiving time, and group them at a certain time interval. Each group of observation data is combined with the position information of the radio detection station for cross-positioning of the unmanned aerial vehicle, and then trajectory information is formed.

[0042] Step S3: Determine whether the broadcast message of the unmanned aerial vehicle is a false message according to the distance. Based on the parsed position of the unmanned aerial vehicle message, calculate the distance between the unmanned aerial vehicle and the radio detection station. If the distance between the two is greater than 3 times the coverage range of the radio detection station, it is determined that the broadcast message of the unmanned aerial vehicle is a false message; otherwise, go to Step S4 for judgment.

[0043] Step S4: Determine whether the broadcast message of the unmanned aerial vehicle is a false message according to the direction of arrival. Based on the parsed position of the unmanned aerial vehicle message, calculate the theoretical direction of arrival of the radio detection station. If the deviation between the theoretical direction of arrival and the observed direction of arrival of the radio detection station is greater than 3 times the angle measurement accuracy, it is determined that the broadcast message of the unmanned aerial vehicle is a false message; otherwise, go to Step S5 for judgment.

[0044] Step S5: Determine whether the broadcast message of the unmanned aerial vehicle is a false message according to the positioning information. If the deviation between the estimated position of the cross-positioning and the parsed position is greater than 3 times the positioning accuracy of the cross-positioning system, it is determined that the broadcast message of the unmanned aerial vehicle is a false message; otherwise, go to Step S6 for judgment.

[0045] Step S6: Determine whether the broadcast message of the unmanned aerial vehicle is a false message according to the positioning trajectory. Based on the parsed message of the unmanned aerial vehicle, obtain the broadcast trajectory of the unmanned aerial vehicle. If the movement trend of the observed trajectory is inconsistent with the broadcast trajectory, it is determined that the broadcast message of the unmanned aerial vehicle is a false message; otherwise, it is determined that the broadcast message of the unmanned aerial vehicle is a true message.

[0046] Further, in step S1, the UAV periodically broadcasts a remote identification message signal according to national standards. The message contains the unique identification code of the UAV and real-time position information. The radio detection station has the ability of two-dimensional radio signal direction finding, calculates the direction of arrival of the message signal, that is, the pitch angle and azimuth angle. The radio detection station has the ability to analyze communication protocols, and analyzes the unique identification code of the UAV and real-time position information in the message. The radio detection station can mark the time stamp of the received signal.

[0047] Further, in step S2, the radio detection stations adopt satellite time synchronization to synchronize time with each other, and the observation coordinate systems are unified. The observation data of each radio detection station are collected in real time, and the observation data are classified according to the unique identification code of the target UAV. The classified data are sorted according to the reception time sequence. The classified data are grouped at a certain time interval. The observation data from 1 second back in time at an interval of 0.1 second are taken as a group. The cross-positioning of the target UAV is carried out by combining the position of the detection station and the observation data of each group to obtain the observed position of the UAV. The Kalman filter is applied to the observed position of the UAV to obtain the observed trajectory.

[0048] Further, according to S3 to S6, from dimensions such as distance, angle, positioning, and trajectory, it is sequentially determined whether the UAV broadcast message is true.

[0049] Embodiment 2

[0050] As Figure 2 shown, a false broadcast message identification system for UAVs assisted by radio direction finding and positioning in this embodiment includes at least one UAV, at least two radio detection stations, and at least one server, where:

[0051] The UAV periodically broadcasts a remote identification message signal according to national standards;

[0052] The radio detection station adopts satellite time synchronization, receives the message signal and marks the time stamp, calculates the direction of arrival of the message signal, and analyzes the unique identification code of the UAV and the position information in the message;

[0053] The server receives the observation data reported by each radio detection station, classifies the observation data of the radio detection station based on the unique identification code of the UAV, sorts them according to the reception time sequence, and groups them at a certain time interval (the observation data from 1 second back in time at an interval of 0.1 second are taken as a group). The cross-positioning of the UAV is carried out by combining the position information of the radio detection station and the observation data of each group, and the Kalman filter is applied to the observed position of the UAV to obtain the observed trajectory;

[0054] Judge whether the UAV broadcast message is a false message according to the distance. Based on the parsed position of the UAV message, calculate the distance from the radio detection station. If the distance between the two is greater than 3 times the coverage range of the radio detection station, it is determined that the UAV broadcast message is a false message. Otherwise, judge whether the UAV broadcast message is a false message according to the incoming wave direction. Based on the parsed position of the UAV message, calculate the theoretical incoming wave direction of the radio detection station. If the deviation between the theoretical incoming wave direction and the observed incoming wave direction of the radio detection station is greater than 3 times the angle measurement accuracy, it is determined that the UAV broadcast message is a false message. Otherwise, judge whether the UAV broadcast message is a false message according to the positioning information. If the deviation between the cross-location estimated position and the parsed position is greater than 3 times the positioning accuracy of the cross-location system, it is determined that the UAV broadcast message is a false message. Otherwise, judge whether the UAV broadcast message is a false message according to the positioning trajectory. Based on the parsed UAV message, obtain the UAV broadcast trajectory. If the movement trends of the observed trajectory and the broadcast trajectory are inconsistent, it is determined that the UAV broadcast message is a false message. Otherwise, it is determined that the UAV broadcast message is a true message.

[0055] As mentioned above, it is only the preferred specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A method for identifying false broadcast messages of unmanned aerial vehicles based on radio direction finding and positioning, characterized in that, It includes the following steps: Step S1: The drone periodically broadcasts a remote identification message signal containing the unique identification code and real-time position information of the drone according to national standards; At least two radio detection stations receive the message signal, mark the timestamp, calculate the direction of arrival of the message signal, and parse the unique identification code and real-time position information of the drone in the message; Step S2: Classify the observation data of multiple radio detection stations according to the unique identification code of the drone, and sort them in chronological order of the timestamp; Group the classified observation data at certain time intervals; Combine the position information of the radio detection stations to perform cross-positioning of the drone on the observation data within each time interval to form drone observation trajectory information; Step S3: Judge whether the drone broadcast message is a false message according to the distance: Based on the position parsed from the drone message, calculate the distance to the radio detection station. If the distance between the two is greater than 3 times the coverage range of the radio detection station, it is determined that the drone broadcast message is a false message. Otherwise, go to Step S4; Step S4: Judge whether the drone broadcast message is a false message according to the direction of arrival: Based on the position parsed from the drone message, calculate the theoretical direction of arrival of the radio detection station. If the deviation between the theoretical direction of arrival and the observed direction of arrival of the radio detection station is greater than 3 times the angle measurement accuracy, it is determined that the drone broadcast message is a false message. Otherwise, go to Step S5; Step S5: Judge whether the drone broadcast message is a false message according to the positioning information: Compare the deviation between the cross-positioning estimated position and the position parsed from the message. If the deviation between the cross-positioning estimated position and the parsed position is greater than 3 times the positioning accuracy of the cross-positioning system, it is determined that the drone broadcast message is a false message. Otherwise, go to Step S6; Step S6: Judge whether the drone broadcast message is a false message according to the positioning trajectory: Based on the position parsed from the drone message, obtain the drone broadcast trajectory. If the motion trends of the observed trajectory and the drone broadcast trajectory are inconsistent, it is determined that the drone broadcast message is a false message. Otherwise, it is determined that the drone broadcast message is a true message.

2. The method for identifying false broadcast messages of an unmanned aerial vehicle based on radio direction finding and positioning according to claim 1, wherein In Step S1, the radio detection station has the two-dimensional radio signal direction finding ability to calculate the direction of arrival of the message signal, that is, the pitch angle and the azimuth angle; The radio detection station has the communication protocol parsing ability to parse the unique identification code and real-time position information of the drone in the message; The radio detection station can mark the timestamp of the received signal.

3. The method for identifying false broadcast messages of an unmanned aerial vehicle based on radio direction finding and positioning according to claim 1, wherein In Step S2 The radio detection stations are time-synchronized with each other, and the observation coordinate systems are unified; Collect the observation data of each radio detection station in real time, and classify the observation data according to the unique identification code of the target drone; Sort the classified data in chronological order of reception time; Group the classified data at certain time intervals. The observation data that traces back 1 second every 0.1 second is used as a group; Combine the position of the detection station and the observation data of each group to perform cross-positioning of the target drone to obtain the observed position of the drone; Filter the observed position of the drone to obtain the observed trajectory.

4. The time synchronization between the radio detection stations according to claim 3, characterized in that, The radio detection station uses satellite time synchronization. Specifically, the radio detection station uses network time synchronization.

5. A false broadcast message recognition system for unmanned aerial vehicles based on radio direction finding and positioning, characterized in that, It includes: At least one drone, which is used to periodically broadcast a remote identification message signal containing the unique identification code and real-time position information of the drone according to national standards; At least two radio detection stations, which are used to receive and analyze the message signal, mark the timestamp, calculate the direction of arrival of the incoming wave, and extract the unique identification code and position information of the drone; And At least one server, which is used to receive the observation data reported by each radio detection station, execute the drone false broadcast message identification method described in any one of claims 1-4, complete the determination of false messages, and output the determination result.

6. The false broadcast message recognition system for unmanned aerial vehicles based on radio direction finding and positioning according to claim 5, characterized in that, The radio detection stations are deployed at fixed sites or mobile vehicles in different geographical locations, and transmit data to the server in real time through an encrypted communication link.

7. The false broadcast message recognition system for unmanned aerial vehicles based on radio direction finding and positioning according to claim 5, characterized in that, The server is configured with a parallel computing module, which is used to perform parallel processing on the observation data grouping, cross-positioning, and trajectory filtering of multiple drone identification codes, and support millisecond-level real-time supervision of hundreds of drones.

Images