Unmanned aerial vehicle tracking angle measurement phase zero calibration device

Abstract

The utility model discloses an unmanned aerial vehicle tracking angle measurement phase zero calibration device, and particularly relates to the field of unmanned aerial vehicle measurement and control, the unmanned aerial vehicle tracking angle measurement phase zero calibration device comprises a servo turntable, a directional antenna, a ground terminal, an image collector, a monitor and a servo controller, the directional antenna is fixed on the servo turntable, and the directional antenna is used for receiving a telemetering radio frequency signal; a radio frequency cable is connected with a ground terminal; the ground terminal is connected with the directional antenna, and the ground terminal is used for processing the telemetering radio frequency signal received by the directional antenna to obtain telemetering data; the image collector is arranged on the directional antenna, and the image collector is used for collecting an image of the unmanned aerial vehicle; the monitor is connected with the image collector and used for adjusting the focal length of the image collector and displaying an unmanned aerial vehicle picture collected by the image collector, and the monitor is further connected with the ground terminal and used for determining servo control data according to telemetry data; and the servo controller is connected with the servo turntable and the monitor and is used for rotating the servo turntable according to the servo control data. And accurate phase zero calibration can be ensured.

Description

Technical Field

[0001] This application relates to the field of UAV measurement and control, and in particular to a UAV tracking angle measurement phase zeroing device. Background Technology

[0002] In UAV data link telemetry and control systems, ground control stations commonly use two tracking methods for UAVs: automatic tracking and GPS / BeiDou guidance. Among the automatic tracking methods, the phase-comparison angle measurement scheme is widely used due to its high measurement accuracy and reliability. Ideally, when the ground control station's directional antenna is aligned with the UAV, the phase of the RF signal received by the two receiving channels of the ground data terminal from the UAV's onboard omnidirectional antenna is the same, calculating that the angle of the UAV deviating from the normal of the ground directional antenna is zero. However, in practical applications, due to the asymmetry of antenna array elements, inconsistencies in RF cable lengths, and inconsistencies in the RF signal wiring lengths on the circuit board, the signal paths of the two receiving channels of the ground data terminal are not the same length, resulting in a constant phase difference. Consequently, the calculated angle of the UAV deviating from the normal of the directional antenna is not zero, affecting the UAV data link's telemetry and control distance, bit error rate, and other performance indicators. Therefore, to optimize the performance of the UAV data link, it is essential to ensure that the phase difference of the signals from the two receiving channels of the ground data terminal is also consistent when the ground control station's directional antenna is aligned with the UAV. Existing solutions include: adjusting the antenna element positions to achieve good symmetry; eliminating carrier phase difference caused by cable length difference by adjusting the lengths of the two receiving channel cables; adjusting the layout of RF signals on the circuit board to eliminate phase difference caused by RF signal layout; and using a three-channel antenna, with one channel used for calibration. The first three methods require significant time and resources and still cannot completely eliminate phase difference. The fourth method requires increasing the antenna size and the number of array elements, thus increasing costs. Utility Model Content

[0003] The main purpose of this application is to provide a UAV tracking angle measurement phase zeroing device, which aims to solve the problem that existing phase zeroing devices cannot completely eliminate phase difference.

[0004] To achieve the above objectives, this application provides a UAV tracking angle measurement phase zeroing device, comprising: a servo turntable; a directional antenna fixed on the servo turntable, the directional antenna being used to receive telemetry radio frequency signals; connected to a ground terminal via a radio frequency cable; a ground terminal connected to the directional antenna, the ground terminal being used to process the telemetry radio frequency signals received by the directional antenna to obtain telemetry data; an image acquisition device mounted on the directional antenna, the image acquisition device being used to acquire images of the UAV; a monitor connected to the image acquisition device, used to adjust the focal length of the image acquisition device and display the UAV image acquired by the image acquisition device, the monitor also being connected to the ground terminal, used to determine servo control data based on the telemetry data; and a servo controller connected to the servo turntable and the monitor, used to rotate the servo turntable according to the servo control data.

[0005] Optionally, the directional antenna is a dual-channel antenna.

[0006] Optionally, the ground terminal includes: a frequency converter sampler connected to a directional antenna, the frequency converter sampler being used to frequency-convert and sample the telemetry radio frequency signal received by the directional antenna; a data processor connected to the frequency converter sampler and a monitor, the data processor being used to process the frequency-converted and sampled signal to obtain telemetry data, and to send the telemetry data to the monitor; and a housing, in which the frequency converter sampler and the data processor are located.

[0007] Optionally, the housing is provided with two radio frequency ports, and the two radio frequency channel interfaces of the directional antenna are respectively connected to the two radio frequency ports through radio frequency cables.

[0008] Optionally, the frequency converter sampler is an AD9361 RF chip.

[0009] Optionally, the data processor is a ZYNQ7100 chip.

[0010] Compared with the prior art, the beneficial effects of this application are as follows:

[0011] This practical UAV tracking angle measurement phase zeroing device, combined with an image acquisition unit, adjusts the angle of the directional antenna and the focal length of the image acquisition unit via a servo turntable before the UAV takes off, ensuring the directional antenna is aligned with the UAV and guaranteeing the accuracy of the initial phase difference, thereby ensuring phase zeroing during the tracking process. It employs a dual-channel antenna, adjusting the angle of the directional antenna via the servo turntable to ensure consistent phase difference between the two channels, achieving UAV tracking angle measurement phase zeroing. Compared to adjusting the symmetry of antenna array elements, cable length, and circuit board RF signal wiring, this method reduces adjustment time and increases zeroing accuracy. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of a UAV tracking angle measurement phase zeroing device according to this application;

[0013] Figure 2 This is a schematic diagram illustrating the principle of calculating the deviation angle of a UAV in a UAV tracking angle measurement phase zeroing method according to this application.

[0014] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0016] The first embodiment of this utility model provides a drone tracking angle measurement phase zeroing device, such as... Figure 1 As shown, the system includes a servo turntable 10, a directional antenna 20, a ground terminal 30, an image acquisition unit 40, a monitor 50, and a servo controller 60. The directional antenna 20 is fixed on the servo turntable 10 and can be a channel antenna. The directional antenna 20 is used to receive telemetry radio frequency signals and is connected to the ground terminal 30 via an radio frequency cable. The ground terminal 30 is connected to the directional antenna 20 and is used to process the telemetry radio frequency signals received by the directional antenna 20 to obtain telemetry data. The image acquisition unit 40 is mounted on the directional antenna 20. The monitor 50 is connected to the image acquisition unit 40 and is used to adjust the focus of the image acquisition unit 40 and display the image from the image acquisition unit 40. The monitor 50 is also connected to the ground terminal 30 and is used to determine servo control data based on the telemetry data. The servo controller 60 is connected to the servo turntable 10 and the monitor 50 and is used to rotate the servo turntable 10 according to the servo control data.

[0017] Specifically, the image acquisition unit 40 can be a camera, and the ground terminal 30 includes a frequency converter sampler 31, a data processor 32, and a housing 33. The frequency converter sampler 31 is connected to the directional antenna 20 and is used to convert and sample the telemetry radio frequency signal received by the directional antenna 20. The data processor 32 is connected to the frequency converter sampler 31 and the monitor 50. The data processor 32 is used to process the frequency-converted and sampled signal to obtain telemetry data and send the telemetry data to the monitor 50. The frequency converter sampler 31 and the data processor 32 are located in the housing 33. For example, the frequency converter sampler 31 is an AD9361 radio frequency chip, and the data processor 32 is a ZYNQ7100 chip.

[0018] Furthermore, the housing 33 is provided with two radio frequency ports, namely radio frequency port A and radio frequency port B. The two radio frequency interfaces (radio frequency port C and radio frequency port D) of the directional antenna 20 are respectively connected to the two radio frequency ports through radio frequency cables.

[0019] In this embodiment, a dual-channel antenna is used. The angle of the directional antenna 20 is adjusted by rotating the servo turntable 10 to eliminate the phase difference between the two channels, so that the directional antenna 20 is aligned with the UAV. This achieves phase zeroing of the UAV tracking angle measurement, which reduces adjustment time compared to adjusting the symmetry of the antenna array elements, adjusting the cable length, and the RF signal wiring of the circuit board. Before the UAV takes off, the angle of the directional antenna 20 and the focal length of the image acquisition unit 40 are adjusted by the servo turntable 10 to align the directional antenna 20 with the UAV, ensuring the accuracy of the initial phase difference and thus ensuring phase zeroing during the tracking process.

[0020] The zeroing method of this practical UAV tracking angle measurement phase zeroing device includes the following steps:

[0021] Step S1: Before the drone takes off, the monitor 50 sends servo control data to the servo controller 60 and adjusts the focal length of the image acquisition unit 40. The servo controller 60 controls the servo turntable 10 to rotate and adjust the angle of the directional antenna 20 so that the drone is located in the center of the field of view of the image acquisition unit 40.

[0022] Specifically, the monitor 50 can be a computer equipped with servo control software and flight monitoring software. Before the drone takes off, the operator manually inputs servo control data into the servo control software. The servo controller 60 receives the servo control data and controls the servo turntable 10 to rotate, which in turn rotates the directional antenna 20 until the drone enters the field of view of the image acquisition unit 40, thus completing the initial alignment. Next, the operator operates the flight monitoring software to adjust the focus of the image acquisition unit 40 so that the drone is centered in the field of view of the image acquisition unit 40, and the drone image occupies more than 1 / 3 of the entire image, thus completing the precise alignment of the drone. While the monitor 50 sends servo control data to the servo controller 60, the servo controller 60 returns its own servo status data to the monitor 50.

[0023] After alignment is completed, calibration begins. The start of calibration can be indicated by the monitor 50 sending the calibration command to the ground terminal 30 in the form of a remote control data frame. After receiving the calibration command, the ground terminal 30 performs an initial phase difference calculation on the signals of the two receiving channels, as follows.

[0024] In step S2, the ground terminal 30 determines the initial phase difference between the two receiving channels based on the telemetry radio frequency signals received by the two receiving channels, and saves it. Based on the initial phase difference, the initial deflection angle of the directional antenna 20 is determined.

[0025] The formula for calculating the initial phase difference is:

[0026]

[0027] In the formula, Q A Q B These are the orthogonal components of the signals from the two receiving channels, I. A I B These are the in-phase components of the signals from the two receiving channels, respectively.

[0028] Combination Figure 2 The formula for calculating the initial deflection angle is as follows:

[0029]

[0030] In the formula, λ is the wavelength and D is the distance between the two array elements.

[0031] After obtaining the initial deflection angle, the UAV takes off and is tracked. Specifically, the tracking command can be sent to the ground terminal 30 in the form of a remote control data frame through the monitor 50. The ground terminal 30 performs real-time tracking, as follows.

[0032] Step S3: After the UAV takes off, the ground terminal 30 determines the real-time phase difference between the two receiving channels based on the telemetry radio frequency signals received by the two receiving channels, determines the real-time deflection angle of the directional antenna 20 based on the real-time phase difference, and determines the required deflection angle of the directional antenna 20 based on the real-time deflection angle and sends the required deflection angle of the directional antenna 20 to the monitor 50.

[0033] The formula for calculating the phase difference is:

[0034]

[0035] In the formula, Q A Q B These are the orthogonal components of the signals from the two receiving channels, I. A I B These are the in-phase components of the signals from the two receiving channels, respectively.

[0036] The formula for calculating the deflection angle is:

[0037]

[0038] In the formula, λ is the wavelength and D is the distance between the two array elements.

[0039] The formula for calculating the deflection angle is:

[0040]

[0041] In the formula, θ 实 θ0 is the real-time deflection angle, and θ0 is the initial deflection angle.

[0042] In step S4, the monitor 50 sends the deflection angle of the directional antenna 20 to the servo controller 60 using a servo control data frame. The servo controller 60 controls the servo turntable 10 to rotate so that the directional antenna 20 is aligned with the UAV.

[0043] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A drone tracking angle measurement phase zeroing device, characterized in that, include: Servo turntable; A directional antenna is fixed on the servo turntable, and the directional antenna is used to receive telemetry radio frequency signals; Connected to a ground terminal via an RF cable; A ground terminal is connected to the directional antenna, and the ground terminal is used to process the telemetry radio frequency signals received by the directional antenna to obtain telemetry data; An image acquisition device is mounted on the directional antenna and is used to acquire images of the UAV. The monitor is connected to the image acquisition device to adjust the focus of the image acquisition device and display the drone images captured by the image acquisition device; the monitor is also connected to the ground terminal to determine servo control data based on the telemetry data. A servo controller, connected to the servo turntable and the monitor, is used to rotate the servo turntable according to the servo control data.

2. The UAV tracking angle measurement phase zeroing device according to claim 1, characterized in that, The directional antenna is a dual-channel antenna.

3. The UAV tracking angle measurement phase zeroing device according to claim 2, characterized in that, The ground terminal includes: A frequency converter sampler is connected to the directional antenna, and the frequency converter sampler is used to convert and sample the telemetry radio frequency signal received by the directional antenna. A data processor is connected to the frequency converter sampler and the monitor. The data processor is used to process the frequency converter and sampled signals to obtain telemetry data, and send the telemetry data to the monitor. The housing contains the frequency converter sampler and the data processor.

4. The UAV tracking angle measurement phase zeroing device according to claim 3, characterized in that, The housing is provided with two radio frequency ports, and the two array element interfaces of the directional antenna are respectively connected to the two radio frequency ports through radio frequency cables.

5. The UAV tracking angle measurement phase zeroing device according to claim 3, characterized in that, The frequency converter sampler is an AD9361 RF chip.

6. The UAV tracking angle measurement phase zeroing device according to claim 3, characterized in that, The data processor is a ZYNQ7100 chip.

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