Ground mobile antenna tracking, pointing and guiding method and system for long-range unmanned aerial vehicle

Abstract

The present invention relates to a method for tracking and directing a ground mobile antenna for a long-range unmanned aerial vehicle. After establishing communication, the positions of the target unmanned aerial vehicle and the ground terminal device are acquired in real time based on the GNSS positioning modules carried by the target unmanned aerial vehicle and the ground terminal device. The high-sensitivity gyro north finder is used to acquire the attitude change of the ground terminal device's gimbal, and the posture change of the mobile ground terminal device and the unmanned aerial vehicle is quickly measured. This solves the problem of automatic control of the rapid alignment of the antenna pointing caused by the ground mobile antenna due to position movement and its own attitude change and the change in the relative posture of the unmanned aerial vehicle in the previous technology. In addition, the system formed by this method can achieve high-precision pointing tracking with fast response, and the system has strong adaptability. After its own posture changes, it can quickly detect and automatically realign without manual adjustment, and can adapt to various vehicle-mounted, ship-mounted, airborne, handheld and other application scenarios.

Description

Technical Field

[0001] The present invention relates to the field of long-distance unmanned aerial vehicle communication, and in particular to a ground mobile antenna tracking, pointing and guiding method and system for a long-distance unmanned aerial vehicle. Background Art

[0002] The automatic tracking, pointing, and guidance method for ground-based mobile antennas proposed by the researchers behind this technical solution is designed for use with long-range, autonomous unmanned aerial vehicles (UAVs), providing a reference for optimizing UAV communication technology. In recent years, UAVs, as effective, economical, and practical aerial platforms, have played a vital role in a variety of fields, including defense and security monitoring, reconnaissance, flight testing, natural disaster surveillance, urban planning, atmospheric and marine environmental monitoring, traffic patrol, communications relay, television broadcasting, aerial photography, and engineering construction.

[0003] Long-range autonomous cruise unmanned aerial vehicles (UAVs) have found widespread application in both military and civilian sectors due to their low-cost, all-weather, long-range surveillance, reconnaissance, and communication relay capabilities over sea and land terrain. Upon reaching a designated cruising position, a long-range autonomous cruise UAV begins autonomous cruising, performing observation or communication relay missions. In these scenarios, the UAV must communicate with the ground in real time, requiring high data transmission rates and high communication distances far exceeding those of traditional UAVs, exceeding 100 kilometers in some scenarios. Therefore, ground antennas must possess high pointing accuracy and rapid tracking capabilities to ensure the communication system meets these requirements.

[0004] Clearly, those skilled in the art understand that research on UAV technology shouldn't be limited to the application functionality and performance of the aircraft itself; it should also focus on overcoming challenges in communication accuracy, efficiency, and smoothness between ground-based mobile antenna systems and the UAV. To meet the requirements of long-distance communication, omnidirectional antennas are currently installed on UAVs, while ground-based communication terminals use directional antennas pointed in the direction of the UAV to ensure link lock and establish communication for data transmission.

[0005] With the expansion of application scenarios, the ground terminals of ultra-long-range automatic cruise unmanned aerial vehicles are gradually developing from fixed terminals to small mobile terminals. The ground antennas of various forms of terminals in mobile state, such as airborne, vehicle-mounted or handheld, will change their own posture and relative posture with respect to the unmanned aerial vehicle during the communication process. These changes will inevitably bring certain instability factors to the communication process. To ensure the quality of communication, the current existing solutions are mostly manual adjustment of the ground antenna direction.

[0006] The researchers who developed the technical solution of the present invention analyzed the manual adjustment of ground antenna pointing techniques or similar techniques used in the past to solve the problem of communication quality being affected by changes in relative posture during communication and found that they have common drawbacks, namely:

[0007] Currently, most small directional ground-based terminal antennas are manually adjusted to maintain their orientation based on the drone's intended flight direction. However, if the mobile antenna carrier moves and its attitude changes, causing the mobile terminal antenna's own attitude relative to its initial position and its position relative to the drone, manual adjustment of the ground antenna's attitude is often required to maintain antenna orientation. This method cannot quickly achieve tracking alignment when the relative position and attitude of the ground terminal and the autonomous cruise drone change rapidly, resulting in antenna lock loss and communication interruption.

[0008] Based on the above analysis, the present invention solves the above problems on the basis of existing technical means, and combines the summary of actual application experience to study a targeted ground mobile antenna tracking and pointing guidance method to achieve rapid pointing tracking of the antenna to the unmanned aerial vehicle, control the pointing accuracy of the ground antenna within the communication requirement range, and thus achieve high-speed communication. At the same time, for the proposed pointing guidance method, when it is specifically implemented, a ground mobile antenna tracking and pointing guidance system suitable for this method can also be summarized. After the technical solution of the present invention is proposed, technical personnel have continuously practiced and analyzed, and it can be proved that the technical solution proposed by the present invention can at least alleviate, or partially solve, or completely solve the problems existing in the existing technology, and it is also beneficial to the application needs of long-distance unmanned aerial vehicle communications. Summary of the Invention

[0009] In response to the above defects, the present invention provides a ground mobile antenna tracking, pointing and guidance method for a long-range unmanned aerial vehicle, which is beneficial to solving the problem of rapid alignment and automatic control of the antenna pointing after the ground mobile antenna moves due to position movement and changes in its own posture relative to the unmanned aerial vehicle, thereby realizing automatic tracking and control of the ground mobile antenna.

[0010] To achieve the above object, the present invention adopts the following technical solutions:

[0011] A method for tracking and directing a ground-based mobile antenna for a long-range unmanned aerial vehicle is provided, which is used to ensure that the antenna can quickly track the unmanned aerial vehicle and control the pointing accuracy of the ground antenna within the communication requirement range. The method comprises the following steps:

[0012] Step I:

[0013] The drone is equipped with a carrying device and a ground terminal device, wherein the ground terminal device includes a ground communication terminal communication module, a ground communication terminal antenna, and an automatic control gimbal mounted with the antenna. The automatic control gimbal includes a sensor, a controller, and an actuator. The sensor includes a GNSS positioning module, a gyro north finder, and an electronic level carried by the gimbal. The actuator consists of two micro motors for pitch and yaw directions.

[0014] Step II:

[0015] The UAV determines its own longitude, latitude, and altitude based on its own GNSS positioning module, and follows the predetermined track to the predetermined location. The UAV hovers and waits for communication to be established before autonomously cruising according to the predetermined track position of the UAV. At this time, the GNSS positioning module of the ground terminal device obtains its own longitude, latitude, and altitude; the controller calculates the azimuth of the UAV relative to the ground antenna based on the position of the UAV and the ground antenna, that is, the north-east angle of the UAV relative to the ground antenna:

[0016]

[0017] Among them, lon UAV ,lat UAV 、H UAV The longitude, latitude, and altitude of the drone are in sequence; lon GT ,lat GT 、 H GT The GNSS positioning module on the ground terminal device outputs the longitude, latitude and altitude of the gimbal's absolute position in the geographic coordinate system. is the arc value between the UAV and the ground antenna device;

[0018]

[0019] The controller calculates the pitch angle of the UAV relative to the ground device based on the position of the UAV and the ground antenna:

[0020]

[0021] Where Re is the average radius of the earth, and in the north-east navigation coordinate system of the ground device, the polar coordinate position of the UAV device (α GT_UAV β GT_UAV );

[0022] In the north-east navigation coordinate system of the ground terminal device, the three-axis Euler coordinates of the UAV position are:

[0023]

[0024] In the north-east navigation coordinate system of the ground device, the direction vector of the UAV is: [x gyro_UAV y gyro_UAV z gyro_UAV ] T ;

[0025] According to the heading angle in the northeast coordinate system output by the north finder Pitch angle θ gyro , roll angle ψ gyro , calculate the attitude matrix of the ground terminal device antenna body coordinate system, which is the conversion matrix from the north-east ground to the antenna body coordinate system:

[0026]

[0027] Convert the antenna target position direction vector in the north-east coordinate system of the ground terminal device to the antenna target position direction vector in the antenna body coordinate system:

[0028]

[0029] Calculate the target direction vector S antb_UAV =[x antb_UAV y antb_UAV z antb_UAV ] T and antenna direction vector S antb_ANT =[1 0 0] T The angle between the two:

[0030]

[0031] Determine whether the antenna needs to be maneuvered in azimuth and pitch by the motor based on the antenna field of view. If δ is less than the antenna pointing accuracy requirement, the antenna can remain stationary. If δ is greater than the antenna pointing accuracy requirement, the motor needs to be moved forward to control the antenna's azimuth and pitch.

[0032] Step III:

[0033] According to the attitude angle Euler of the gimbal coordinate system in the antenna coordinate system ant2table =[0 -β wheel0 0], calculate the attitude matrix of the ground terminal device's gimbal coordinate system, which is the conversion matrix from the antenna coordinate system to the gimbal coordinate system:

[0034]

[0035] Among them, β wheel0 Feedback the current motor rotation angle for the pitch axis forward motor;

[0036] Calculate the direction vector of the antenna target pointing in the gimbal coordinate system as follows:

[0037]

[0038] Then the azimuth of the antenna target pointing in the gimbal coordinate system is:

[0039]

[0040] Then, in the gimbal coordinate system, the pitch angle of the antenna target is:

[0041]

[0042] Step IV:

[0043] The gimbal controller outputs a command to the yaw control motor, and the yaw control motor rotates at an angle α wheel =α tableb_UAV After the yaw control motor is in place, the gimbal controller outputs a command to the pitch control motor, and the pitch control motor rotates at an angle β wheel =β tableb_UAV -β wheel0 After the yaw control motor is in place, the current pitch control motor angle is fed back to the controller and assigned to β wheel0 , for use in the next cycle calculation, and the cycle control is completed.

[0044] By summarizing the above steps, the whole process also includes the following methods:

[0045] After the first alignment is completed by calculating and controlling the predetermined latitude and longitude of the UAV hovering position, the UAV establishes communication with the ground communication terminal, and the UAV starts automatic cruise through the ground terminal command. After that, the ground terminal device locates the UAV position every second based on the airborne GNSS positioning module sent by the UAV received by the communication terminal, and performs relative position calculation every second. When the angle between the antenna target direction vector and the current direction vector exceeds the antenna pointing accuracy requirement, the antenna pointing tracking control is performed, and the direction vector of the UAV in the gimbal coordinate system is calculated in sequence, the current pitch axis control motor angle is obtained, the conversion matrix from the antenna coordinate system to the gimbal coordinate system is calculated, the antenna target pointing in the gimbal body coordinate system is calculated, and the gimbal pitch control motor angle is obtained. If the tracking is not ended, the relative position calculation will continue to be performed in a loop every second until the tracking is ended.

[0046] For the above technical solutions, technicians can choose the following technical means to further implement them, including:

[0047] For the ground terminal device, the output coordinate origin of the gyro north finder carried by the gimbal is located at the center of the gimbal, the X axis points to the north, the Y axis points to the east, and the Z axis points directly downward in the northeast navigation coordinate system. The current heading angle of the gimbal around the Z axis is north-east. Pitch angle θ around the Y axis gyro , roll angle around the X axis ψ gyro ,This coordinate system is the geographic coordinate system. When the gimbal moves and the attitude changes, the origin moves, but the directions of the three axes remain unchanged;

[0048] The ground terminal device automatically controls the gimbal's coordinate system as a moving coordinate system. When the gimbal moves, the origin moves accordingly. When the gimbal's yaw axis control motor rotates, the three-axis pointing direction also rotates. Rotating only the pitch axis motor does not cause the three-axis pointing direction to change.

[0049] The coordinate system of the antenna body of the ground terminal device is a moving coordinate system. When the yaw axis control motor rotates, the relative position angle between the antenna coordinate system and the gimbal coordinate system remains unchanged; when the pitch axis control motor rotates, the relative pitch angle between the antenna coordinate system and the gimbal coordinate system changes; when the pitch axis motor rotates through β wheel When the gimbal's three-axis attitude angle relative to the antenna coordinate system is Euler table2ant =[0 -β wheel 0].

[0050] In addition, the gyro north finder can be installed on the antenna mounting surface and is fixedly connected to the antenna; the controller is mounted on the gimbal, including the gimbal control microprocessor and the system control circuit.

[0051] According to the heading angle in the northeast coordinate system output by the north finder Pitch angle θ gyro , roll angle ψ gyro , calculate the attitude matrix according to the yaw-pitch-roll 3-2-1 rotation matrix.

[0052] Based on the same concept, the present invention can also form the following technical solutions:

[0053] A ground-based mobile antenna tracking, pointing, and guidance system for a long-range unmanned aerial vehicle, comprising:

[0054] A UAV carrying device, comprising a communication module installed on the UAV, an omnidirectional communication antenna assembly, and a GNSS positioning module onboard the UAV;

[0055] The ground terminal device includes a ground communication terminal communication module, a ground communication terminal antenna and an automatic control pan-tilt platform. The automatic control pan-tilt platform includes a sensor, a controller and an actuator module. The sensor includes a pan-tilt platform equipped with a GNSS positioning module and a gyro north finder, so that after being positioned by the GNSS positioning module, the gyro north finder is used to obtain its own posture in the geographic coordinate system.

[0056] Among them, the controller also includes a gimbal control microprocessor, which is used to calculate the relative position of the ground antenna and the unmanned aerial vehicle and the antenna target attitude, convert it to the pitch direction and yaw direction control motor control angle, and drive the step motor to implement rotation control in sequence.

[0057] The present invention comprehensively considers the changes in the posture of the ground mobile antenna of the unmanned aerial vehicle during use. After the initial pointing alignment, communication is established. The real-time positions of the target unmanned aerial vehicle and the ground terminal device are acquired based on the GNSS positioning modules carried by the two. The posture changes of the ground terminal device's gimbal are acquired through a highly sensitive gyro north finder, thereby realizing rapid measurement of the posture changes of the mobile ground terminal device and the unmanned aerial vehicle. This solves the problem of automatic control of the rapid alignment of the antenna pointing caused by the ground mobile antenna's position movement and its own posture changes and the change in the relative posture of the unmanned aerial vehicle in the previous technology.

[0058] The corresponding advantages can also be reflected through the actual application process. Due to the use of highly integrated microprocessors and micro-progressive motors to achieve equipment miniaturization and rapid maneuverability response, the system response time can be as fast as milliseconds, achieving fast response and high-precision pointing tracking. The system has strong adaptability. In addition, it is less restricted by its own posture factors and does not require a horizontal installation plane. After its own posture changes, it can quickly detect and re-align automatically without manual adjustment. It can adapt to various vehicle-mounted, ship-mounted, airborne, handheld and other application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The present invention will be described in further detail below with reference to the accompanying drawings.

[0060] Figure 1 This is a schematic diagram of the system composition of the ground mobile antenna tracking, pointing and guiding method for a long-range unmanned aerial vehicle implemented by the present invention;

[0061] Figure 2 This is a schematic diagram of the ground antenna equipment used in the ground mobile antenna tracking, pointing and guiding method for a long-range unmanned aerial vehicle implemented by the present invention;

[0062] Figure 3 This is a schematic diagram of azimuth calculation;

[0063] Figure 4 This is a schematic diagram of pitch angle calculation;

[0064] Figure 5 The present invention is a method for tracking, pointing and guiding a ground-based mobile antenna for a long-range unmanned aerial vehicle, and a schematic diagram of its control flow. DETAILED DESCRIPTION

[0065] The ground mobile antenna tracking, pointing and guidance method and system for long-range unmanned aerial vehicles implemented by the present invention are beneficial to minimizing one or more problems of the prior art. The purpose of the technical means implemented is to solve the technical problem of rapid alignment and automatic control of the antenna pointing of the ground mobile antenna of a long-range unmanned aerial vehicle after the ground mobile antenna of the long-range unmanned aerial vehicle changes due to position movement and its own posture change and the relative posture of the unmanned aerial vehicle, that is, how to achieve precise automatic tracking control of the ground mobile antenna.

[0066] Example 1

[0067] like Figure 1-4 As shown, the ground mobile antenna tracking and pointing guidance method for a long-range unmanned aerial vehicle implemented by the present invention includes several steps:

[0068] Step (1) Implement the layout of relevant systems and set technical parameters;

[0069] The overall layout of the guidance system is carried out. The system consists of a ground terminal device (GT) and an unmanned aerial vehicle (UAV). The ground terminal device includes a ground communication terminal communication module, a ground communication terminal antenna and an automatic control pan-tilt platform with an antenna installed. The automatic control pan-tilt platform includes a sensor, a controller and an actuator.

[0070] The sensor includes the GNSS positioning module, gyro north finder, and electronic level mounted on the gimbal. The composition of the attitude control gimbal can be referred to as follows: Figure 1 As shown;

[0071] As for the actuator, it consists of two micro-stepping motors (also known as stepping motors) in the pitch and yaw directions;

[0072] As for the controller, it is mounted on the pan / tilt head and includes a pan / tilt head control microprocessor and a system control circuit;

[0073] The drone carrying device includes a communication module installed on the unmanned aerial vehicle, an omnidirectional communication antenna and a GNSS positioning module onboard the unmanned aerial vehicle.

[0074] Furthermore, set the relevant parameters:

[0075] The GNSS positioning module of the drone's onboard device outputs the drone's absolute position in the geographic coordinate system: drone longitude lon UAV , latitude lat UAV , height H UAV ;

[0076] The GNSS positioning module on the ground terminal device outputs the absolute position of the GNSS device itself in the geographic coordinate system: the longitude lon of the ground terminal GT , latitude lat GT , height H GT .

[0077] For the ground terminal device, the coordinate origin of the gyro north finder output by the gimbal is located at the center of the gimbal, the X axis points to the north, the Y axis points to the east, and the Z axis points to the northeast of the ground navigation coordinate system directly below. The current heading angle of the gimbal around the Z axis is north-east. Pitch angle θ around the Y axis gyro , roll angle around the X axis ψ gyro This coordinate system is a geographic coordinate system. When the gimbal moves or changes its attitude, the origin moves, but the three-axis directions remain unchanged. The gyro north finder is installed on the antenna mounting surface and is fixedly connected to the antenna. The reference position for the gyro north finder is as follows: Figure 2 shown.

[0078] For the ground terminal device to automatically control the gimbal body coordinate system, Figure 2 As shown, the origin is at the center, the Z axis is along the azimuth control motor axis, the Y axis is along the pitch control motor axis and is perpendicular to the Z axis, the X axis is perpendicular to the Y axis and the Z axis points forward, satisfying the right-hand rule; this coordinate system is a moving coordinate system, fixed to the gimbal Z axis, that is, the shaft of the yaw control motor. When the gimbal position moves, the origin position moves accordingly. When the gimbal yaw axis control motor rotates, the three axes rotate accordingly. Rotating the pitch axis motor alone does not bring about changes in the three axes' directions.

[0079] For the ground terminal device antenna body coordinate system, the origin is located at the center of the antenna surface, the X axis is always pointing along the antenna, the Y axis is perpendicular to the X axis and is in the same direction as the pitch control motor axis, and the Z axis is perpendicular to the X and Y axis planes, satisfying the right-hand rule; when the ground antenna control gimbal is initialized, the system controls the step motor to return the mechanical position of the gimbal to zero, and the gimbal is in the body coordinate system as follows Figure 2 As shown, the yaw axis advance motor angle at this time is: α wheel =0, pitch axis forward motor rotation angle β wheel=0; at this time, the ground terminal device antenna body coordinate system coincides with the gimbal body coordinate system. This coordinate system is a mobile coordinate system, fixed to the X-axis antenna. When the yaw axis control motor rotates, the relative position angle between the antenna coordinate system and the gimbal coordinate system remains unchanged. When the pitch axis control motor rotates, the relative pitch angle between the antenna coordinate system and the gimbal coordinate system changes. When the pitch axis motor rotates through β wheel When the gimbal's three-axis attitude angle relative to the antenna coordinate system is Euler table2ant =[0 -β wheel 0].

[0080] Step (2) implementing corresponding calculation steps;

[0081] The UAV determines its own latitude and longitude based on its own GNSS positioning module, and flies to the predetermined location according to the planned track. The UAV hovers and waits for communication to be established before it starts autonomous cruising. UAV lat UAV H UAV ); At this time, the ground terminal device (GT) GNSS positioning module obtains its own longitude, latitude, and altitude (lon GT lat GT H GT ), the controller calculates the azimuth and pitch angle of the drone relative to the ground antenna based on the positions of the drone and the ground antenna:

[0082] (1) According to Figure 3 The azimuth angle of the drone relative to the ground antenna device is calculated by the spherical sine formula, that is, the north-east angle of the drone relative to the ground antenna:

[0083]

[0084] in, is the arc value between the UAV and the ground antenna device, according to Figure 3 From the trihedral angle cosine formula we can get:

[0085]

[0086] (2) The positional relationship between the Earth's center (O), the ground terminal (GT), and the unmanned aerial vehicle (UAV) is as follows: Figure 4 As shown, the pitch angle of the UAV relative to the ground device can be calculated:

[0087]

[0088] Where Re is the average radius of the earth. Therefore, in the north-east navigation coordinate system of the ground device, the polar coordinate position (αGT_UAV β GT_UAV );

[0089] In the north-east navigation coordinate system of the ground terminal device, the three-axis Euler coordinates of the UAV position are:

[0090]

[0091] In the north-east navigation coordinate system of the ground device, the direction vector of the UAV is: [x gyro_UAV y gyro_UAV z gyro_UAV ] T ;

[0092] According to the heading angle in the northeast coordinate system output by the north finder Pitch angle θ gyro , roll angle ψ gyro , according to the yaw-pitch-roll 3-2-1 rotation matrix, the attitude matrix of the antenna, i.e. the ground terminal device antenna body coordinate system, is calculated, which is the conversion matrix from the north-east ground to the antenna body coordinate system:

[0093]

[0094] Convert the antenna target position direction vector in the north-east coordinate system of the ground terminal device to the antenna target position direction vector in the antenna body coordinate system:

[0095]

[0096] Calculate the target direction vector S antb_UAV =[x antb_UAV y antb_UAV z antb_UAV ] T The angle between the target direction vector and the antenna direction vector is . The antenna is installed along the X axis of the gimbal. Therefore, the target direction vector and the antenna direction vector S antb_ANT =[1 0 0] T The angle between the two:

[0097]

[0098] Determine whether the antenna needs to be maneuvered in azimuth and pitch by the motor according to the antenna field of view. If δ is less than the antenna pointing accuracy requirement, the antenna can remain stationary. If δ is greater than the antenna pointing accuracy requirement, the antenna needs to be maneuvered in azimuth and pitch by the motor.

[0099] Step (3) calculating the corresponding direction vector, azimuth angle, and pitch angle;

[0100] According to the attitude angle Euler of the gimbal coordinate system in the antenna coordinate system ant2table =[0 -βwheel0 0], according to the yaw-pitch-roll 3-2-1 rotation matrix, the attitude matrix of the gimbal, i.e. the gimbal body coordinate system of the ground terminal device, is calculated, that is, the conversion matrix from the antenna coordinate system to the gimbal body coordinate system:

[0101]

[0102] Among them, β wheel0 Feedback the current motor rotation angle for the pitch axis forward motor.

[0103] Calculate the direction vector of the antenna target pointing in the gimbal coordinate system as follows:

[0104]

[0105] Then the azimuth of the antenna target pointing in the gimbal coordinate system is:

[0106]

[0107] Then, in the gimbal coordinate system, the pitch angle of the antenna target is:

[0108]

[0109] Furthermore, the gimbal controller outputs a command to the yaw control motor, and the yaw control motor rotates at an angle α wheel =α tableb_UAV After the yaw control motor is in place, the gimbal controller outputs a command to the pitch control motor, and the pitch control motor rotates at an angle β wheel =β tableb_UAV -β wheel0 After the yaw control motor is in place, the current pitch control motor angle is fed back to the controller and assigned to β wheel0 , for use in the next cycle calculation, and this cycle control is completed.

[0110] Based on the above analysis, the first ground communication terminal antenna alignment is performed after the UAV reaches the hovering position, and the predetermined UAV hovering position latitude and longitude are used for calculation and control. After the first alignment is completed, the UAV establishes communication with the ground communication terminal, and the UAV starts automatic cruise through the ground terminal command. After that, the ground terminal device locates the UAV position every second according to the UAV sent by the communication terminal to the airborne GNSS positioning module, and performs relative position calculation every second. When the angle between the antenna target direction vector and the current direction vector exceeds the antenna pointing accuracy requirement, the antenna pointing tracking control is performed, the direction vector of the UAV in the gimbal coordinate system is calculated, the current pitch axis control motor angle is obtained, the antenna coordinate system to the gimbal coordinate system conversion matrix is ​​calculated, the antenna target pointing in the gimbal body coordinate system is calculated, and the gimbal pitch control motor angle is obtained. If the tracking is not ended, the relative position calculation per second will continue to be cyclically performed until the tracking is ended. The specific measures can be as follows: Figure 5 The calculation process shown.

[0111] The ground mobile antenna tracking, pointing and guidance method for a long-range unmanned aerial vehicle implemented by the above-mentioned present invention mainly utilizes a predetermined flight trajectory set on the ground to complete the initial pointing alignment at the hovering position, and then combines the GNSS positioning information of the unmanned aerial vehicle in the communication information obtained in real time on the ground to correct the position information of the unmanned aerial vehicle (including longitude, latitude, and altitude) in real time, and further locates according to the GNSS positioning module (including longitude, latitude, and altitude) carried by the gimbal, and uses a gyro north finder to obtain its own posture (including heading angle, pitch angle, and roll angle) in the geographic coordinate system, calculates the relative position of the ground antenna and the unmanned aerial vehicle and the antenna target posture through the gimbal control microprocessor, converts the control angle of the motor in the pitch direction and yaw direction, drives the progressive motor to implement rotation control in sequence, and realizes the rapid pointing tracking of the antenna to the pointing unmanned aerial vehicle, so that the pointing accuracy of the ground antenna is controlled within the communication requirement range, thereby realizing high-speed communication.

[0112] Example 2

[0113] like Figure 1-4 As shown, according to the above-mentioned ground mobile antenna tracking, pointing and guiding method for a long-range unmanned aerial vehicle implemented by the present invention, based on the same concept, the system composition adopted by the ground mobile antenna tracking, pointing and guiding method mainly includes a ground terminal device and a UAV carrying device;

[0114] The UAV carrying device includes a communication module installed on the UAV, an omnidirectional communication antenna assembly and a GNSS positioning module onboard the UAV;

[0115] The ground terminal device includes a ground communication terminal communication module, a ground communication terminal antenna and an automatic control pan-tilt platform. The automatic control pan-tilt platform is mainly composed of three modules: sensors, controllers and actuators. The sensors include a GNSS positioning module and a gyro north finder mounted on the pan-tilt platform; the actuators are composed of a micro progressive motor in the pitch direction and a micro progressive motor in the yaw direction; the controller is mounted on the pan-tilt platform, including a communication interface circuit, a progressive motor drive acquisition circuit and a pan-tilt platform control microprocessor.

[0116] There are no fixed requirements for the specific layout and installation position of each device in the system. Any assembly method and assembly position can be achieved by technical personnel based on application requirements or design requirements, using conventional technical means in the field when actually building the system. Therefore, there is no need to elaborate on them in this article.

[0117] In this specification, the use of terms such as "this embodiment" or "specific implementation" means that the specific features, methods, steps, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of these terms do not necessarily refer to the same embodiment or example; furthermore, the specific features, methods, steps, materials, or characteristics described may be combined in any appropriate manner in any one or more embodiments or examples.

[0118] In the description of this specification, the terms "connection", "setting", "having", etc. are understood in a broad sense. For example, "connection" can be a fixed connection or an indirect connection through an intermediate component without affecting the relationship between components and technical effects. It can also be an integral connection or a partial connection. As in this example, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0119] The above description of the embodiments is intended to facilitate understanding and application by persons of ordinary skill in the art. It is obvious that persons skilled in the art can easily make various modifications to these examples and apply the general principles described herein to other embodiments without requiring creative effort. Therefore, this case is not limited to the above embodiments. Modifications in the following situations should be within the scope of protection: ① A new technical solution based on the technical solution of the present invention and combined with existing common knowledge, where the technical effect produced by the new technical solution does not exceed the technical effect of the present invention, such as a technical solution formed by using a GNSS positioning module mounted on a gimbal for positioning and a gyro north finder to obtain the attitude of the unmanned aerial vehicle in a geographic coordinate system, and the technical effect produced does not exceed the technical effect of the present invention; ② An equivalent replacement of some features of the technical solution of the present invention with a known technology, where the technical effect produced is the same as the technical effect of the present invention, such as an equivalent replacement of some auxiliary components involved; ③ An expansion based on the technical solution of the present invention, where the substantive content of the expanded technical solution does not exceed the technical solution of the present invention; ④ An equivalent transformation of the content of the text of the present invention or the drawings in the specification, where the resulting technical means is applied to solutions in other related technical fields.

Claims

1. A method for tracking and directing a ground-based mobile antenna for a long-range unmanned aerial vehicle, which is used to ensure that the antenna can quickly track the unmanned aerial vehicle and control the pointing accuracy of the ground antenna within the communication requirement range, characterized by: The steps of the method include: Step I: The drone is equipped with a carrying device and a ground terminal device, wherein the ground terminal device includes a ground communication terminal communication module, a ground communication terminal antenna, and an automatic control gimbal mounted with the antenna. The automatic control gimbal includes a sensor, a controller, and an actuator. The sensor includes a GNSS positioning module, a gyro north finder, and an electronic level carried by the gimbal. The controller includes a gimbal control microprocessor and a system control circuit. The actuator consists of two micro motors for pitch and yaw directions. Step II: The UAV determines its own longitude, latitude, and altitude based on its own GNSS positioning module, and follows the predetermined track to the predetermined location. The UAV hovers and waits for communication to be established before autonomously cruising according to the predetermined track position of the UAV. At this time, the GNSS positioning module of the ground terminal device obtains its own longitude, latitude, and altitude; the controller calculates the azimuth of the UAV relative to the ground antenna based on the position of the UAV and the ground antenna, that is, the north-east angle of the UAV relative to the ground antenna: ； in, 、 、 The sequence is the longitude, latitude, and altitude of the drone; 、 、 The GNSS positioning module on the ground terminal device outputs the longitude, latitude and altitude of the gimbal's absolute position in the geographic coordinate system. is the arc value between the UAV and the ground antenna device; ； The controller calculates the pitch angle of the UAV relative to the ground device based on the position of the UAV and the ground antenna: ； Where Re is the average radius of the earth, and in the north-east navigation coordinate system of the ground device, the polar coordinate position of the unmanned aerial vehicle device is ; In the north-east navigation coordinate system of the ground terminal device, the three-axis Euler coordinates of the UAV position are: ； In the north-east navigation coordinate system of the ground device, the direction vector of the UAV is: ; According to the heading in the northeast coordinate system output by the north finder , pitch angle , roll angle , calculate the attitude matrix of the ground terminal device antenna body coordinate system, which is the conversion matrix from the north-east ground to the antenna body coordinate system: ； Convert the antenna target position direction vector in the north-east coordinate system of the ground terminal device to the antenna target position direction vector in the antenna body coordinate system: ； Calculate the target direction vector and antenna direction vector The angle between the two: ； Determine whether the antenna needs to be maneuvered in azimuth and pitch by the motor according to the antenna field of view. If δ is less than the antenna pointing accuracy requirement, the antenna can remain stationary. If δ is greater than the antenna pointing accuracy requirement, the motor needs to be moved forward to control the antenna azimuth and pitch. Step III: According to the attitude angle of the gimbal coordinate system in the antenna coordinate system , calculate the attitude matrix of the ground terminal device gimbal body coordinate system, which is the conversion matrix from the antenna coordinate system to the gimbal body coordinate system: ； in, Feedback the current motor rotation angle for the pitch axis forward motor; Calculate the direction vector of the antenna target pointing in the gimbal coordinate system as follows: ； Then the azimuth of the antenna target pointing in the gimbal coordinate system is: ； Then, in the gimbal coordinate system, the pitch angle of the antenna target is: ； Step IV: The gimbal controller outputs instructions to the yaw control motor, which controls the rotation angle of the motor. After the yaw control motor is in place, the gimbal controller outputs instructions to the pitch control motor, and the pitch control motor turns After the yaw control motor is in place, the current pitch control motor angle is fed back to the controller. , for use in the next cycle calculation, and the control of this cycle is completed.

2. The method for tracking and directing a ground-based mobile antenna for a long-range unmanned aerial vehicle according to claim 1, wherein: The method further comprises the steps of: After the first alignment is completed by calculating and controlling the predetermined latitude and longitude of the UAV hovering position, the UAV establishes communication with the ground communication terminal, and the UAV starts automatic cruise through the ground terminal command. After that, the ground terminal device locates the UAV position every second according to the airborne GNSS positioning module sent by the UAV received by the communication terminal, and performs relative position calculation every second. When the angle between the antenna target direction vector and the current direction vector exceeds the antenna pointing accuracy requirement, the antenna pointing tracking control is performed, and the direction vector of the UAV in the gimbal coordinate system is calculated in sequence, the current pitch axis control motor angle is obtained, the antenna coordinate system to the gimbal coordinate system conversion matrix is ​​calculated, the antenna target pointing in the gimbal body coordinate system is calculated, and the gimbal pitch control motor angle is obtained. If the tracking is not ended, the relative position calculation per second will continue to be cyclically performed until the tracking is ended.

3. The method for tracking and directing a ground-based mobile antenna for a long-range unmanned aerial vehicle according to claim 1, wherein: For the ground terminal device, the output coordinate origin of the gyro north finder carried by the gimbal is located at the center of the gimbal, the X axis points to the north, the Y axis points to the east, and the Z axis points directly downward in the northeast navigation coordinate system. The current heading angle of the gimbal around the Z axis is north-east. , pitch angle around the Y axis , Roll angle around the X axis ,This coordinate system is the geographic coordinate system. When the gimbal position moves and the attitude changes, the origin position moves, but the directions of the three axes remain unchanged.

4. The method for tracking and directing a ground-based mobile antenna for a long-range unmanned aerial vehicle according to claim 1, wherein: The ground terminal device automatically controls the gimbal's coordinate system as a moving coordinate system. When the gimbal moves, the origin moves accordingly. When the gimbal's yaw axis control motor rotates, the three-axis pointing direction rotates accordingly. Rotating only the pitch axis motor does not bring about changes in the three-axis pointing direction.

5. The method for tracking and directing a ground-based mobile antenna for a long-range unmanned aerial vehicle according to claim 1, wherein: The coordinate system of the antenna body of the ground terminal device is a moving coordinate system. When the yaw axis control motor rotates, the relative position angle between the antenna coordinate system and the gimbal coordinate system remains unchanged; when the pitch axis control motor rotates, the relative pitch angle between the antenna coordinate system and the gimbal coordinate system changes; when the pitch axis motor rotates When the three-axis attitude angle of the gimbal relative to the antenna coordinate system is .

6. The method for tracking, pointing, and guiding a ground-based mobile antenna for a long-range unmanned aerial vehicle according to any one of claims 1 to 5, wherein: The gyro north finder is installed on the antenna installation surface and is fixedly connected to the antenna.

7. The method for tracking, pointing, and guiding a ground-based mobile antenna for a long-range unmanned aerial vehicle according to any one of claims 1 to 5, characterized in that: The controller is mounted on the pan / tilt platform and includes a pan / tilt platform control microprocessor and a system control circuit.

8. The method for tracking and directing a ground-based mobile antenna for a long-range unmanned aerial vehicle according to claim 1, wherein: According to the heading angle in the northeast coordinate system output by the north finder , pitch angle , roll angle , calculate the attitude matrix according to the yaw-pitch-roll 3-2-1 rotation matrix.

9. A ground-based mobile antenna tracking, pointing, and guiding system for a long-range unmanned aerial vehicle using the ground-based mobile antenna tracking, pointing, and guiding method for a long-range unmanned aerial vehicle as claimed in claim 1, characterized in that: The system comprises: A UAV carrying device, comprising a communication module installed on the UAV, an omnidirectional communication antenna assembly, and a GNSS positioning module onboard the UAV; The ground terminal device includes a ground communication terminal communication module, a ground communication terminal antenna and an automatic control pan-tilt platform.

10. The ground-based mobile antenna tracking, pointing, and guidance system for a long-range unmanned aerial vehicle according to claim 9, characterized in that: The automatic control pan-tilt platform includes a sensor, a controller and an actuator module. The sensor includes a GNSS positioning module and a gyro north finder mounted on the pan-tilt platform, so that after being positioned by the GNSS positioning module, the gyro north finder is used to obtain its own posture in the geographic coordinate system; The controller also includes a communication interface circuit, a progressive motor drive acquisition circuit, and a pan / tilt control microprocessor; The actuator is composed of a micro-motor in the pitch direction and a micro-motor in the yaw direction; Among them, the gimbal control microprocessor calculates the relative position of the ground antenna and the unmanned aerial vehicle and the antenna target attitude, converts it to the pitch direction and yaw direction control motor control angle, and drives the step motor to implement rotation control in sequence.

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