A regional unmanned aerial vehicle dynamic time synchronization method and system

Abstract

The application discloses a regional unmanned aerial vehicle dynamic time synchronization method and system, relates to unmanned aerial vehicles and time synchronization, and comprises the following steps: generating a clock reference signal as a frequency time reference benchmark of other components; generating a first time synchronization electric text frame corresponding to the clock reference signal and modulating the first time synchronization electric text frame to generate a transmission enhanced radio frequency signal; receiving an enhanced radio frequency signal transmitted by a ground center, demodulating the first time synchronization electric text frame, and measuring an observation quantity after frame synchronization; forming a second time synchronization electric text frame according to a measured time delay and unmanned aerial vehicle self-measured time information; calculating an initial clock difference by analyzing the measured time delay and the unmanned aerial vehicle self-measured time information in the second time synchronization electric text frame; correcting the initial clock difference data according to unmanned aerial vehicle motion errors to generate corrected clock difference results; and adjusting an unmanned aerial vehicle local clock reference signal according to the clock difference results. The method can improve the time synchronization precision between loads of an air-based regional navigation enhancement system.

Description

Technical Field

[0001] This application relates to unmanned aerial vehicles (UAVs) and time synchronization technology, and more particularly to a method and system for dynamic time synchronization of UAVs in a region. Background Technology

[0002] When a satellite navigation system becomes unavailable in a certain area due to obstruction, interference, or other reasons, a drone carrying a navigation enhancement payload can supplement the satellite navigation system as an airborne regional navigation enhancement system, providing positioning and timing services within the area.

[0003] The foundation for the high-precision time synchronization and positioning of the airborne regional navigation augmentation system is the accurate synchronization of system time among all UAVs. A time error of 1 microsecond can lead to a ranging error of 300 meters. Summary of the Invention

[0004] This application provides a method and system for dynamic time synchronization of unmanned aerial vehicles (UAVs) in a region, which proposes a method for dynamic time synchronization between UAVs and ground centers within a region, improves the time synchronization accuracy between payloads of an airborne regional navigation augmentation system, and thus ensures the high accuracy and availability of airborne regional navigation augmentation services.

[0005] This application provides a method for dynamic time synchronization of unmanned aerial vehicles (UAVs) in a region, including:

[0006] Generate a clock reference signal as a frequency and time reference for other components;

[0007] The first time synchronization message frame corresponding to the clock reference signal is modulated to generate a transmission enhanced intermediate frequency signal. The enhanced intermediate frequency signal is up-converted into an enhanced radio frequency signal by a frequency conversion power amplifier unit, and the enhanced radio frequency signal is transmitted to the ground center using a transceiver antenna unit.

[0008] The system receives the enhanced radio frequency signal transmitted by the ground center, down-converts it to an enhanced intermediate frequency signal through a frequency conversion power amplifier unit, demodulates the first time synchronization message frame, and measures the observations after frame synchronization, including the measurement delay.

[0009] A second time synchronization message frame is generated based on the measurement delay and the UAV's own measurement time information;

[0010] Analyze the measurement delay and the UAV's own measurement time information in the second time synchronization message frame to calculate the initial clock difference;

[0011] The initial clock error data is corrected for UAV motion error, and the corrected clock error result is generated.

[0012] Adjust the drone's local clock reference signal synchronization based on the clock difference results.

[0013] Optionally, the generated clock reference signal may include one or more of the following signals: 10MHz, 10.23MHz, 1PPS.

[0014] Optionally, the first time synchronization message frame includes a frame header, local time, measurement time, measurement delay, and verification content.

[0015] Optionally, the measurement of observations after frame synchronization includes: after acquiring the enhancement signal, measuring the time difference between the first rising edge of the signal message frame header and the rising edge of the time-frequency unit 1PPS to obtain the measurement delay.

[0016] Optionally, the initial clock difference is calculated by parsing the measurement delay in the second time synchronization message frame and the UAV's own measurement time information to satisfy:

[0017]

[0018] In the formula, T1 and T2 are the UAV delay and ground center delay values ​​measured in the same second, respectively.

[0019] Optionally, the initial clock error data can be corrected for UAV motion errors to satisfy:

[0020]

[0021] In the formula, v is the radial relative velocity of the line connecting the UAV and the center of the ground; Δt is the time difference between the UAV signal transmission time and the time delay measurement time; and c is the speed of light.

[0022] This application also proposes a regional unmanned aerial vehicle (UAV) dynamic time synchronization system, including:

[0023] The time-frequency unit is used to generate internal multiple clock reference signals and send them to the enhanced signal transceiver unit.

[0024] An enhanced signal transceiver unit is used to generate a clock reference signal as a frequency and time reference for other components, modulate the first time synchronization message frame corresponding to the clock reference signal to generate a transmitted enhanced intermediate frequency signal, input the enhanced intermediate frequency signal into the frequency converter power amplifier unit, receive the enhanced intermediate frequency signal output by the frequency converter power amplifier unit, demodulate the first time synchronization message frame, and measure the observation after frame synchronization, including the measurement delay.

[0025] The frequency conversion power amplifier unit is used to downconvert the received area navigation enhancement radio frequency signal to intermediate frequency, and to upconvert the transmitted area navigation enhancement intermediate frequency signal to radio frequency and amplify the power.

[0026] The transceiver antenna unit is used to transmit the radio frequency signal output by the frequency converter power amplifier unit, and at the same time input the received spatial signal to the frequency converter power amplifier unit.

[0027] The information processing unit is used to generate a second time synchronization message frame based on the measurement delay and the UAV's own measurement time information, and send it to the enhanced signal transceiver unit; and,

[0028] Analyze the measurement delay and the UAV's own measurement time information in the second time synchronization message frame to calculate the initial clock difference;

[0029] The initial clock error data is corrected for UAV motion error, and the corrected clock error result is generated.

[0030] Adjust the drone's local clock reference signal synchronization based on the clock difference results.

[0031] The method in this application embodiment can improve the time synchronization accuracy between payloads of the airborne regional navigation augmentation system, thereby ensuring the high accuracy and availability of airborne regional navigation augmentation services.

[0032] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0033] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0034] Figure 1 This is a basic flowchart illustrating the regional UAV dynamic time synchronization method according to an embodiment of this application.

[0035] Figure 2 This application presents a regional UAV communication architecture for a regional UAV dynamic time synchronization method according to an embodiment of the present application.

[0036] Figure 3 This is a schematic diagram of the architecture of a regional unmanned aerial vehicle (UAV) dynamic time synchronization system according to an embodiment of this application. Detailed Implementation

[0037] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0038] This application provides a method for dynamic time synchronization of unmanned aerial vehicles (UAVs) in a region, such as... Figure 1 , Figure 2 Includes the following steps:

[0039] In step S101, a clock reference signal is generated as a frequency and time reference for other component units. In a specific example, this can be implemented based on a time-frequency unit. In this specific example, the clock reference signal generated by the time-frequency unit includes one or more of the following signals: 10MHz, 10.23MHz, and 1PPS.

[0040] In step S102, the first time synchronization message frame corresponding to the clock reference signal is modulated to generate a transmission enhanced intermediate frequency (IF) signal, and the enhanced IF signal is transmitted to the ground center. In a specific example, this step is implemented using an enhanced signal transceiver unit, which transmits the generated area navigation enhanced radio frequency signal to the ground area. In a specific example, the frequency of the first time synchronization message frame can be set to 1Hz, and the first time synchronization message frame includes a frame header, local time, measurement time, measurement delay, and verification content.

[0041] In step S103, the enhanced radio frequency signal transmitted by the ground center is received, the first time synchronization message frame is demodulated, and an observation is measured after frame synchronization. The observation includes a measurement delay. In a specific example, the measurement of the observation after frame synchronization includes: after acquiring the enhanced intermediate frequency signal, measuring the time difference between the first rising edge of the signal message frame header and the rising edge of the time-frequency unit 1PPS to obtain the measurement delay.

[0042] In step S104, a second time synchronization message frame is formed based on the measurement delay and the UAV's own measurement time information, and sent to the enhanced signal transceiver unit. Additionally, the measurement delay and the UAV's own measurement time information in the second time synchronization message frame are parsed to calculate the initial clock difference. Specifically, this can be implemented through an information processing unit. The content format of the time synchronization message frame is the same as in the previous example. The information processing unit also parses the time synchronization message frame to extract the delay and measurement time of the ground center's measurement of the UAV.

[0043] In step S105, the initial clock error data is corrected for UAV motion error to generate the corrected clock error result.

[0044] In step S106, the UAV's local clock reference signal is synchronized according to the clock difference result. In a specific example, the corrected clock difference data is received through the time and frequency unit, and the local clock reference signal is synchronized with the ground center. The adjustment method may include phase modulation, frequency modulation, etc.

[0045] The method in this application embodiment can improve the time synchronization accuracy between payloads of the airborne regional navigation augmentation system, thereby ensuring the high accuracy and availability of airborne regional navigation augmentation services.

[0046] In some embodiments, the initial clock difference is calculated by parsing the measurement delay in the second time synchronization message frame and the UAV's own measurement time information to satisfy:

[0047]

[0048] In the formula, T1 and T2 are the UAV delay and ground center delay values ​​measured in the same second, respectively.

[0049] In some embodiments, the UAV motion error correction of the initial clock difference data satisfies:

[0050]

[0051] In the formula, v is the radial relative velocity of the line connecting the UAV and the center of the ground; Δt is the time difference between the UAV signal transmission time and the time delay measurement time; and c is the speed of light.

[0052] The method for dynamic time synchronization of regional UAVs in this application reuses regional enhanced radio frequency signals to correct the motion error model of low-speed UAVs on the original clock difference data, and has the characteristics of strong practicality and high accuracy.

[0053] This application also proposes a regional unmanned aerial vehicle (UAV) dynamic time synchronization system, such as... Figure 3 As shown, it includes:

[0054] The time-frequency unit is used to generate internal multiple clock reference signals and send them to the enhanced signal transceiver unit.

[0055] An enhanced signal transceiver unit is used to generate a clock reference signal as a frequency and time reference for other components. It modulates the first time synchronization message frame corresponding to the clock reference signal to generate an enhanced intermediate frequency (IF) signal. The enhanced IF signal is up-converted to an enhanced radio frequency (RF) signal by a frequency converter power amplifier unit. The enhanced RF signal is transmitted to the ground center using a transceiver antenna unit. The enhanced RF signal transmitted by the ground center is received and down-converted to an enhanced IF signal by a frequency converter power amplifier unit. The first time synchronization message frame is demodulated, and observations are measured after frame synchronization. The observations include measurement delay.

[0056] In a specific example, the receiving function of the enhanced signal transceiver unit is to receive the transmitted signal from the ground center, measure the time delay, and demodulate the message to obtain the time delay of the UAV transmitted signal from the ground center; the transmitting function is to modulate the time synchronization message frame and generate the area navigation enhancement signal to be transmitted to the ground area.

[0057] The enhanced signal transceiver unit may include a processor, analog-to-digital converter chip, digital-to-analog converter chip, clock chip, power supply chip, etc.

[0058] The frequency conversion power amplifier unit is used to downconvert the received area navigation enhancement radio frequency signal to intermediate frequency, and to upconvert the transmitted area navigation enhancement intermediate frequency signal to radio frequency and amplify the power.

[0059] The transceiver antenna unit is used to transmit the radio frequency signal output by the frequency converter power amplifier unit, and simultaneously input the received spatial signals to the frequency converter power amplifier unit. In a specific example, the transceiver antenna unit may include an anti-interference receiving antenna, a transmitting antenna, etc.

[0060] The information processing unit is used to generate a second time synchronization message frame based on the measurement delay and the UAV's own measurement time information, and send it to the enhanced signal transceiver unit; and,

[0061] Analyze the measurement delay and the UAV's own measurement time information in the second time synchronization message frame to calculate the initial clock difference;

[0062] The initial clock error data is corrected for UAV motion error, and the corrected clock error result is generated.

[0063] Adjust the drone's local clock reference signal synchronization based on the clock difference results.

[0064] In a specific example, the information processing unit may include a processor, a network chip, etc.

[0065] The system for dynamic time synchronization of unmanned aerial vehicles (UAVs) in the region according to the embodiments of this application utilizes the original service signals and hardware resources of the airborne regional augmentation system to achieve clock synchronization of UAVs with the ground center through signal interaction of time synchronization message frames between the UAVs and the ground center.

[0066] It should be noted that, in the embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0067] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0068] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0069] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims. All of these forms are within the protection scope of this application.

Claims

1. A method for dynamic time synchronization of unmanned aerial vehicles (UAVs) in a region, characterized in that, include: Generate a clock reference signal as a frequency and time reference for other components; The first time synchronization message frame corresponding to the clock reference signal is modulated to generate a transmission enhanced intermediate frequency signal. The enhanced intermediate frequency signal is up-converted into an enhanced radio frequency signal by a frequency conversion power amplifier unit, and the enhanced radio frequency signal is transmitted to the ground center using a transceiver antenna unit. The system receives the enhanced radio frequency signal transmitted by the ground center, down-converts it to an enhanced intermediate frequency signal through a frequency conversion power amplifier unit, demodulates the first time synchronization message frame, and measures the observations after frame synchronization, including the measurement delay. The initial clock difference is calculated based on the measurement delay and the UAV's own measurement time information; The initial clock error data is corrected for UAV motion error, and the corrected clock error result is generated. Adjust the drone's local clock reference signal synchronization based on the clock difference results; The initial clock bias is calculated based on the measurement delay and the UAV's own measurement time information: In the formula, and These are the drone latency and ground center latency values ​​measured in the same second, respectively. and All of these are measurement delays, and the measurement within the same second refers to the UAV's own measurement time information.

2. The regional UAV dynamic time synchronization method as described in claim 1, characterized in that, The generated clock reference signal includes one or more of the following signals: 10MHz, 10.23MHz, and 1PPS.

3. The regional UAV dynamic time synchronization method as described in claim 1, characterized in that, The first time synchronization message frame includes a frame header, local time, measurement time, measurement delay, and verification content.

4. The regional UAV dynamic time synchronization method as described in claim 3, characterized in that, The measurement observations after frame synchronization include: after acquiring the enhanced intermediate frequency signal, measuring the time difference between the first rising edge of the signal message frame header and the rising edge of the time-frequency unit 1PPS to obtain the measurement delay.

5. The regional UAV dynamic time synchronization method as described in claim 1, characterized in that, Correcting UAV motion errors using initial clock bias data: In the formula, The radial relative velocity between the UAV and the center of the ground; This represents the time difference between the time the UAV signal was transmitted and the time delay was measured. It is the speed of light.

6. A regional unmanned aerial vehicle (UAV) dynamic time synchronization system, characterized in that, include: The time-frequency unit is used to generate internal multiple clock reference signals and send them to the enhanced signal transceiver unit. An enhanced signal transceiver unit is used to generate a clock reference signal as a frequency and time reference for other components, modulate the first time synchronization message frame corresponding to the clock reference signal to generate a transmitted enhanced intermediate frequency signal, input the enhanced intermediate frequency signal into the frequency converter power amplifier unit, receive the enhanced intermediate frequency signal output by the frequency converter power amplifier unit, demodulate the first time synchronization message frame, and measure the observation after frame synchronization, including the measurement delay. The frequency conversion power amplifier unit is used to downconvert the received area navigation enhancement radio frequency signal to intermediate frequency, and to upconvert the transmitted area navigation enhancement intermediate frequency signal to radio frequency and amplify the power. The transceiver antenna unit is used to transmit the radio frequency signal output by the frequency converter power amplifier unit and to input the received spatial signal to the frequency converter power amplifier unit. The information processing unit is used to generate a second time synchronization message frame based on the measurement delay and the UAV's own measurement time information, and send it to the enhanced signal transceiver unit; and, Analyze the measurement delay and the UAV's own measurement time information in the second time synchronization message frame to calculate the initial clock difference; The initial clock error data is corrected for UAV motion error, and the corrected clock error result is generated. Adjust the drone's local clock reference signal synchronization based on the clock difference results; The initial clock bias is calculated based on the measurement delay and the UAV's own measurement time information: In the formula, and These are the drone latency and ground center latency values ​​measured in the same second, respectively. and All of these are measurement delays, and the measurement within the same second refers to the UAV's own measurement time information.

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