An air-ground coordinated UAV take-off and landing system

Abstract

This application provides an air-to-ground coordinated drone takeoff and landing system, relating to the technical field of vehicle-mounted drone platforms. The system comprises: a vehicle-mounted drone airfield, a leveling module, and a coordinated landing module. The vehicle-mounted drone airfield is capable of displacement and attitude adjustment for drone takeoff and landing. The leveling module is used to level the vehicle-mounted drone airfield to maintain a horizontal position. The coordinated landing module is used to obtain the position and speed of the vehicle-mounted drone airfield and the position and speed of the drone, thereby controlling the movement of the vehicle-mounted drone airfield and guiding the drone's landing flight, thereby achieving coordinated landing of the vehicle-mounted drone airfield and the drone. The system of this application can increase the landing speed of a drone on the vehicle-mounted drone airfield.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle-mounted UAV platforms, and in particular to an air-ground coordinated UAV take-off and landing system. Background Art

[0002] Currently, the use of unmanned vehicles equipped with drones is widespread. While the drone is operating, the vehicle will simultaneously conduct coordinated detection on the ground. This allows the drone to land directly on the nearest unmanned vehicle for charging, rather than returning to its takeoff location. This not only allows for coordinated detection of targets through both ground and air methods, but also effectively expands the drone's detection range in a single operation by reducing the drone's return distance.

[0003] For vehicle-mounted multi-rotor drone platforms, since the vehicle may tilt due to terrain factors during operation, and multi-rotor drones can only take off and land on a horizontal surface, a properly designed vehicle-mounted airport is required to enable normal takeoff and landing of vehicle-mounted multi-rotor drones. Currently, existing vehicle-mounted drone airport technologies mainly include vehicle-mounted drone airports that automatically center and assist landing of multi-rotor drones during landing, and vehicle-mounted drone airports that assist drone takeoff and landing. This technology can only assist takeoff and landing when the vehicle-mounted drone airport is horizontal or nearly horizontal, and only controls the X, Y, and Z axis position of the vehicle-mounted drone airport. It cannot complete the vehicle-mounted drone airport's active leveling and assisted takeoff and landing function when the vehicle is tilted. Existing vehicle-mounted airport technical solutions are mostly used for drone assisted takeoff and landing when the vehicle is operating on a smooth road surface and the airport is not tilted. They are not suitable for vehicle-mounted drone systems used in field exploration to assist multi-rotor drones in bumpy road conditions. Summary of the Invention

[0004] In view of this, the present application provides an air-ground coordinated UAV take-off and landing system to solve the above technical problems.

[0005] The embodiment of the present application provides an air-ground coordinated UAV take-off and landing system, comprising: a vehicle-mounted UAV airport, a leveling module, and a coordinated landing module;

[0006] The vehicle-mounted UAV airport is capable of performing displacement adjustment and attitude adjustment to enable the take-off and landing of the UAV;

[0007] The leveling module is used to perform leveling control on the vehicle-mounted drone airport to keep the vehicle-mounted drone airport level;

[0008] The collaborative landing module is used to obtain the position and speed of the vehicle-mounted drone airport and the position and speed of the drone, thereby controlling the movement of the vehicle-mounted drone airport and guiding the landing flight of the drone, thereby realizing the collaborative landing of the vehicle-mounted drone airport and the drone.

[0009] Furthermore, the vehicle-mounted drone airport includes: a base plate fixed on the vehicle, a helipad and six adjustable support rods; six first mounting seats (P1, P2, P3, P4, P5, P6) are arranged on the lower surface of the helipad; six second mounting seats (B1, B2, B3, B4, B5, B6) are arranged on the upper surface of the base plate; the support rod includes a first universal joint, an electric push rod and a second universal joint, the six first universal joints are respectively fixed on the first mounting seats (P1, P2, P3, P4, P5, P6), and the six second universal joints are respectively fixed on the second mounting seats (B1, B2, B3, B4, B5, B6).

[0010] Furthermore, the six first mounting seats (P1, P2, P3, P4, P5, P6) are evenly distributed on the same circle, the radius of the circle is RP, and the six second mounting seats (B1, B2, B3, B4, B5, B6) are evenly distributed on the same circle, the radius of the circle is RB, and the radius RP is smaller than the radius RB.

[0011] Furthermore, the leveling module is specifically used to:

[0012] Get the extension lengths of the six electric push rods when the apron of the vehicle-mounted drone airport is level;

[0013] Get the extension length and thrust of the six electric push rods at the current moment;

[0014] Calculate the difference between the extension length and thrust of each electric push rod at the current moment and the extension length and thrust of each electric push rod when the vehicle-mounted drone airport is horizontal, and obtain 12 deviations;

[0015] The LQR controller is used to process the 12 deviations to obtain the incremental values ​​of the extension lengths and thrusts of the six electric push rods at the next moment;

[0016] The extension length of the electric push rods is adjusted by using the incremental values ​​of the extension lengths and the incremental values ​​of the thrust of the six electric push rods.

[0017] Furthermore, the extension lengths of the six electric push rods at the current moment are obtained; including:

[0018] Get the positions of the six first universal joints of the vehicle-mounted drone airport in the motion coordinate system of the vehicle-mounted drone airport at the current moment;

[0019] Calculate the positions of the six first gimbals in the absolute coordinate system of the vehicle-mounted drone airport:

[0020] (x i ,y i ,z i )=H×(x ai ,y ai ,zai )

[0021] Among them, (x i ,y i ,z i ) is the three-dimensional coordinate of the i-th first universal joint in the absolute coordinate system of the vehicle-mounted UAV airport, i = 1, 2, 3, 4, 5, 6, (x ai ,y ai ,z ai ) is the three-dimensional coordinate of the i-th first universal joint in the motion coordinate system of the vehicle-mounted drone airport; H is the transformation matrix between the motion coordinate system and the absolute coordinate system of the vehicle-mounted drone airport;

[0022] Calculate the extension length of each electric push rod at the vehicle-mounted drone airport:

[0023]

[0024] Among them, L i is the extension length of the ith electric push rod; (x bi ,y bi ,z bi ) is the three-dimensional coordinate of the i-th second universal joint in the motion coordinate system of the vehicle-mounted UAV airport.

[0025] Furthermore, the parameter solving process of the LQR controller includes:

[0026] Establish the dynamic equations of the vehicle-mounted UAV airport:

[0027]

[0028] Among them, m is the load mass of the vehicle-mounted UAV airport, M is the mass of the vehicle-mounted UAV airport, J1, J2, and J3 are the three moments of inertia in the moment of inertia matrix of the airport respectively; ω x ,ω y ,ω z is the angular velocity of the vehicle-mounted UAV airport rotating around the three axes of the absolute coordinate system; ε x ,ε y ,ε z is the angular acceleration of the vehicle-mounted UAV airport rotating around the three axes of the absolute coordinate system; F1(t), F2(t), F3(t), F4(t), F5(t) and F6(t) are the thrusts of the six electric push rods at time t; is the acceleration of the vehicle-mounted UAV airport in the three directions of the absolute coordinate system; g is the gravitational constant; de 1i is the cosine of the X direction of the ith electric push rod in the absolute coordinate system; h 1i is the cosine of the X direction of the i-th electric push rod in the motion coordinate system; de 2iis the cosine of the Y direction of the i-th electric push rod in the absolute coordinate system; h 2i is the cosine of the Y direction of the i-th electric push rod in the motion coordinate system; de 3i is the cosine of the Z direction of the ith electric push rod in the absolute coordinate system; h 3i is the cosine of the Z direction of the i-th electric push rod in the motion coordinate system;

[0029] According to the above dynamic equations of the vehicle-mounted UAV airport, select As the state quantity of the airport state space equation, after linearization, the state space equation of the vehicle-mounted drone airport can be obtained as:

[0030]

[0031]

[0032] Among them, x, y, z are the three-dimensional coordinates of the vehicle-mounted drone airport in the absolute coordinate system. is the speed of the vehicle-mounted UAV airport in the three directions of the absolute coordinate system, α, β and γ are the roll angle, pitch angle and yaw angle of the vehicle-mounted UAV airport; A is the system matrix, B is the control matrix, C is the output matrix, and D is the direct transfer matrix; u(t) is the 12 deviations; z(t) is the output;

[0033] According to the cost functional J:

[0034]

[0035] Select appropriate matrices Q and R, and calculate the parameters of the LQR controller that constitutes the full state feedback by calculating the optimal solution.

[0036] Furthermore, the collaborative landing module includes: an inertial measurement unit, an RTK unit, a communication unit, a calculation unit and a sending unit;

[0037] The inertial measurement unit is used to measure the speed of the vehicle-mounted drone at the airport;

[0038] The RTK unit is used to measure the position of the vehicle-mounted UAV airport;

[0039] The communication unit is used to communicate data with the drone, obtain the drone's position and speed, and send the drone's expected position and expected speed at the next moment to the drone's flight control system;

[0040] The calculation unit is used to calculate the expected position and expected speed of the drone at the next moment and the expected position and expected speed of the vehicle-mounted drone airport at the next moment according to the position and speed of the vehicle-mounted drone airport at the current moment, the position and speed of the drone at the current moment, the expected position and expected speed of the preset virtual navigator relative to the drone at the next moment, the expected position and expected speed of the preset virtual navigator relative to the vehicle-mounted drone airport at the next moment, the expected relative position and expected relative speed of the drone relative to the vehicle-mounted drone airport at the next moment, and the expected relative position and expected relative speed of the preset vehicle-mounted drone airport relative to the drone at the next moment, until the position of the drone at the current moment coincides with the position of the vehicle-mounted drone airport at the current moment;

[0041] The sending unit is used to send the expected position and expected speed of the vehicle-mounted drone airport at the next moment to the displacement controller of the vehicle-mounted drone airport.

[0042] Furthermore, the expected position and expected speed of the drone at the next moment are calculated, including:

[0043] The expected position and expected speed of the drone at the next moment are:

[0044]

[0045] Among them, p ad (t+Δt) and v ad (t+Δt) is the expected position and expected speed of the UAV at the next moment t+Δt; p v (v) and v v (t) is the actual position and actual speed of the virtual navigator at the current time t; p vad (t+Δt) and v vad (t+Δt) is the expected relative position and expected relative speed of the virtual navigator relative to the UAV at the next moment t+Δt; p g (t) and v g (t) is the actual position and actual speed of the vehicle-mounted UAV airport at the current time t; p agd (t+Δt) and v agd (t+Δt) is the expected relative position and expected relative speed of the UAV relative to the vehicle-mounted UAV airport at the next time t+Δt; a1 and b1 are constants.

[0046] Furthermore, the expected position and expected speed of the vehicle-mounted drone airport at the next moment are calculated, including:

[0047] The expected position and expected speed of the vehicle-mounted drone airport at the next moment are:

[0048]

[0049] Among them, p gd (t+Δt) and v gd (t+Δt) is the expected position and expected speed of the vehicle-mounted UAV airport at the next moment t+Δt; p vgd (t) and v vgd (t) is the expected relative position and expected relative speed of the virtual navigator relative to the vehicle-mounted UAV airport at the next time t+Δt; p a (t) and v a (t) is the actual position and actual speed of the UAV at the current time t; p gad (t) and v gad (t) is the expected relative position and expected relative speed of the vehicle-mounted UAV airport relative to the UAV at the next time t+Δt; a2 and b2 are constants.

[0050] The system of the present application can improve the landing speed of drones on vehicle-mounted drone airports. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0052] Figure 1 A functional structure diagram of the air-to-ground coordinated UAV take-off and landing system provided in an embodiment of the present application;

[0053] Figure 2 A schematic diagram of the structure of a vehicle-mounted drone airport provided in an embodiment of the present application;

[0054] Figure 3 A schematic diagram of a support rod provided in an embodiment of the present application;

[0055] Figure 4 Schematic diagram of the relative position relationship between the drone and the vehicle-mounted drone airport provided in the embodiment of the present application.

[0056] Figure ID:

[0057] 1-UAV, 2-Vehicle-mounted UAV airport, 3-Apron, 4-Equipment cabin, 5-First universal joint, 6-Electric push rod, 7-Second universal joint, 8-Base plate. DETAILED DESCRIPTION

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0059] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0060] First, a brief introduction to the design concept of the embodiments of the present application is given.

[0061] To achieve the leveling of a vehicle-mounted drone airport, this application provides a full-state control method for the LQR controller of the six-degree-of-freedom Stewart platform. This method controls the six-degree-of-freedom state of the vehicle-mounted drone airport, which can meet the position and attitude control of the vehicle-mounted drone airport. It is also applied to the leveling and lifting of the vehicle-mounted drone airport, assisting the takeoff and landing of the drone, so that the drone can complete horizontal takeoff and landing without being interfered with by vehicle terrain factors. In addition, this application also provides a coordinated landing method for the vehicle-mounted drone airport and the drone. Through the coordinated control of the two, the drone and the airport can cooperate with each other to meet the stable takeoff and landing of the drone, effectively improving the stability and speed of the drone landing.

[0062] The technical advantages of this application are:

[0063] 1. When a vehicle is parked on a sloped surface, the airport attached to the vehicle will tilt at the same angle as the vehicle, making the airport plane not level. In this case, the vehicle-mounted drone airport in this application can control the airport's position, attitude, speed and other variables through LQR control to adjust the airport to a horizontal state, allowing the drone to take off smoothly from the horizontal airport.

[0064] 2. When a drone returns to land, it's difficult to control it independently to land at the airport. The vehicle-mounted drone airport in this application uses collaborative control to control the movement of the drone and the airport together, moving them to the desired location. When both the drone and the airport have reached their desired locations, the drone can land directly at the center of the airport, significantly reducing the difficulty of landing and improving landing accuracy and speed.

[0065] After introducing the application scenarios and design concepts of the embodiments of the present application, the technical solutions provided by the embodiments of the present application are described below.

[0066] like Figure 1 As shown, the embodiment of the present application provides an air-ground coordinated UAV take-off and landing system, comprising: a vehicle-mounted UAV airport, a leveling module, and a coordinated landing module;

[0067] The vehicle-mounted UAV airport is capable of performing displacement adjustment and attitude adjustment to enable the take-off and landing of the UAV;

[0068] The leveling module is used to perform leveling control on the vehicle-mounted drone airport to keep the vehicle-mounted drone airport level;

[0069] The collaborative landing module is used to obtain the position and speed of the vehicle-mounted drone airport and the position and speed of the drone, thereby controlling the movement of the vehicle-mounted drone airport and guiding the landing flight of the drone, thereby realizing the collaborative landing of the vehicle-mounted drone airport and the drone.

[0070] like Figure 2 As shown, the vehicle-mounted drone airport includes: a base plate 8 fixed on the vehicle, a helipad 3 and six adjustable support rods; six first mounting seats are set on the lower surface of the helipad 3 and six second mounting seats are set on the upper surface of the base plate 8; the support rod includes a first universal joint 5, an electric push rod 6 and a second universal joint 7, the first universal joint 5 is fixed on the first mounting seat, and the second universal joint 7 is fixed on the second mounting seat.

[0071] like Figure 3 As shown, the six first mounting bases of the six first universal joints are P1, P2, P3, P4, P5, and P6; the six second mounting bases of the six second universal joints are B1, B2, B3, B4, B5, and B6; the six support rods are fixed to P1 and B1, and the six universal joints on the lower platform are grouped in pairs, with B1 and B2 forming one group, B3 and B4 forming another group, and B5 and B6 forming another group. P1, P2, P3, P4, P5, and P6 lie on the same circle with a radius of RP, and the central angle distance between any two adjacent points is 120 degrees. B1, B2, B3, B4, B5, and B6 lie on the same circle with a radius of RB, and the central angle distance between any two adjacent points is 120 degrees; RP is smaller than RB. The central angle between any two nodes within each node is θP from the node center.

[0072] In this embodiment, the leveling module is specifically used to:

[0073] Obtain the extension length and thrust of the six electric push rods when the apron of the vehicle-mounted drone airport is level;

[0074] Get the extension length and thrust of the six electric push rods at the current moment;

[0075] Calculate the difference between the extension length and thrust of each electric push rod at the current moment and the extension length and thrust of each electric push rod when the vehicle-mounted drone airport is horizontal, and obtain 12 deviations;

[0076] The LQR controller is used to process the 12 deviations to obtain the incremental values ​​of the extension lengths and thrusts of the six electric push rods at the next moment;

[0077] The extension length of the electric push rods is adjusted by using the incremental values ​​of the extension lengths and the incremental values ​​of the thrust of the six electric push rods.

[0078] The process of obtaining the extension lengths of the six electric push rods at the current moment includes:

[0079] Get the positions of the six first universal joints of the vehicle-mounted drone airport in the motion coordinate system of the vehicle-mounted drone airport at the current moment;

[0080] Calculate the positions of the six first gimbals in the absolute coordinate system of the vehicle-mounted drone airport:

[0081] (x i ,y i ,z i )=H×(x ai ,y ai ,z ai )

[0082] Among them, (x i ,y i ,z i ) is the three-dimensional coordinate of the i-th first universal joint in the absolute coordinate system of the vehicle-mounted UAV airport, i = 1, 2, 3, 4, 5, 6, (x ai ,y ai ,z ai ) is the three-dimensional coordinate of the i-th first universal joint in the motion coordinate system of the vehicle-mounted drone airport; H is the transformation matrix between the motion coordinate system and the absolute coordinate system of the vehicle-mounted drone airport;

[0083] Calculate the extension length of each electric push rod at the vehicle-mounted drone airport:

[0084]

[0085] Among them, L i is the extension length of the ith electric push rod; (x bi ,y bi ,z bi ) is the three-dimensional coordinate of the i-th second universal joint in the motion coordinate system of the vehicle-mounted UAV airport.

[0086] LQR control eliminates all state feedback and calculates the optimal control variable by weighting the sum of different states. It constructs a quadratic cost function of the system's state changes and actuator inputs over future time periods to obtain the gain matrix with the lowest total cost, thereby generating the desired control sequence. This cost functional can be used to obtain the optimal control solution for the system, forming a full-state feedback control solution.

[0087] Because vehicle-mounted drone airports require a large number of control variables, multiple state variables, such as displacement, rotation angle, velocity, and acceleration, must be controlled in all directions to achieve smooth assisted takeoff and landing. Therefore, the LQR controller can be used to find an optimal solution for each state variable that meets the requirements of the vehicle-mounted drone system.

[0088] The parameter solution process of the LQR controller includes:

[0089] Establish the dynamic equations of the vehicle-mounted UAV airport:

[0090]

[0091] Among them, m is the load mass of the vehicle-mounted UAV airport, M is the mass of the vehicle-mounted UAV airport, J1, J2, and J3 are the three moments of inertia in the moment of inertia matrix of the airport respectively; ω x ,ω y ,ω z is the angular velocity of the vehicle-mounted UAV airport rotating around the three axes of the absolute coordinate system; ε x ,ε y ,ε z is the angular acceleration of the vehicle-mounted UAV airport rotating around the three axes of the absolute coordinate system; F1(t), F2(t), F3(t), F4(t), F5(t) and F6(t) are the thrusts of the six electric push rods at time t; is the acceleration of the vehicle-mounted UAV airport in the three directions of the absolute coordinate system; g is the gravitational constant; de 1i is the cosine of the X direction of the ith electric push rod in the absolute coordinate system; h 1i is the cosine of the X direction of the i-th electric push rod in the motion coordinate system; de 2i is the cosine of the Y direction of the i-th electric push rod in the absolute coordinate system; h 2i is the cosine of the Y direction of the i-th electric push rod in the motion coordinate system; de 3i is the cosine of the Z direction of the ith electric push rod in the absolute coordinate system; h 3i is the cosine of the Z direction of the i-th electric push rod in the motion coordinate system;

[0092] According to the above dynamic equations of the vehicle-mounted UAV airport, select As the state quantity of the airport state space equation, after linearization, the state space equation of the vehicle-mounted drone airport can be obtained as:

[0093]

[0094]

[0095] Among them, x, y, z are the three-dimensional coordinates of the vehicle-mounted drone airport in the absolute coordinate system. is the speed of the vehicle-mounted UAV airport in the three directions of the absolute coordinate system, α, β and γ are the roll angle, pitch angle and yaw angle of the vehicle-mounted UAV airport; A is the system matrix, B is the control matrix, C is the output matrix, and D is the direct transfer matrix; u(t) is the 12 deviations; z(t) is the output;

[0096] According to the cost functional J:

[0097]

[0098] Select appropriate matrices Q and R, and calculate the parameters of the LQR controller that constitutes the full state feedback by calculating the optimal solution.

[0099] The LQR controller of the vehicle-mounted drone airport can control its posture state, speed, and acceleration, achieve smooth movement, and realize the function of assisting drone takeoff and landing, greatly improving the control performance of the vehicle-mounted drone airport.

[0100] Simultaneously controlling the airport's motion during drone landing allows the drone to accurately and quickly land at the center of the airport. For the coordinated control of the vehicle-mounted drone airport and the drone, a virtual navigator approach is used. The virtual navigator is a virtual unmanned vehicle that coordinates the position and attitude of the drone airport and the drone. The virtual navigator's position and attitude are set based on the desired setting. The desired position and attitude of the drone airport and the drone are determined by the relative position and attitude of the virtual navigator, the drone airport, and the drone.

[0101] In this embodiment, the collaborative landing module includes: an inertial measurement unit (IMU), an RTK unit, a communication unit, a computing unit, and a transmitting unit;

[0102] like Figure 2 As shown, an inertial measurement unit (IMU) (not shown), a GPS (not shown), an RTK unit (not shown) and a first communication unit (not shown) are set in the drone 1; the inertial measurement unit (IMU), GPS and RTK unit are used to obtain the position and speed of the drone.

[0103] An equipment compartment 4 is located on the lower surface of the apron 3 of the vehicle-mounted drone airport, housing a leveling module, an inertial measurement unit (IMU), an RTK unit, a computing unit, and a transmitting unit. A second communication unit (not shown) is located on the upper surface of the base plate 8. The IMU and RTK units can obtain the position and velocity information of the vehicle-mounted drone airport. Preferably, the communication units of the vehicle-mounted drone airport and the drones both use Wi-Fi for data transmission.

[0104] The calculation unit is used to calculate the expected position and expected speed of the drone at the next moment and the expected position and expected speed of the vehicle-mounted drone airport at the next moment according to the position and speed of the vehicle-mounted drone airport at the current moment, the position and speed of the drone at the current moment, the expected position and expected speed of the preset virtual navigator relative to the drone at the next moment, the expected position and expected speed of the preset virtual navigator relative to the vehicle-mounted drone airport at the next moment, the expected relative position and expected relative speed of the drone relative to the vehicle-mounted drone airport at the next moment, and the expected relative position and expected relative speed of the preset vehicle-mounted drone airport relative to the drone at the next moment, until the position of the drone at the current moment coincides with the position of the vehicle-mounted drone airport at the current moment;

[0105] Calculating the expected position and speed of the drone at the next moment includes:

[0106] The expected position and expected speed of the drone at the next moment are:

[0107]

[0108] Among them, p ad (t+Δt) and v ad (t+Δt) is the expected position and expected speed of the UAV at the next moment t+Δt; p v (t) and v v (t) is the actual position and actual speed of the virtual navigator at the current time t; p vad (t+Δt) and v vad (t+Δt) is the expected relative position and expected relative speed of the virtual navigator relative to the UAV at the next moment t+Δt; p g (t) and v g (t) is the actual position and actual speed of the vehicle-mounted UAV airport at the current time t; p agd (t+Δt) and v agd (t+Δt) is the expected relative position and expected relative speed of the UAV relative to the vehicle-mounted UAV airport at the next time t+Δt; a1 and b1 are constants.

[0109] Among them, calculating the expected position and expected speed of the vehicle-mounted drone airport at the next moment includes:

[0110] The expected position and expected speed of the vehicle-mounted drone airport at the next moment are:

[0111]

[0112] Among them, p gd (t+Δt) and v gd (t+Δt) is the expected position and expected speed of the vehicle-mounted UAV airport at the next moment t+Δt; p vgd (t) and v vgd (t) is the expected relative position and expected relative speed of the virtual navigator relative to the vehicle-mounted UAV airport at the next time t+Δt; p a (t) and v a (t) is the actual position and actual speed of the UAV at the current time t; p gad (t) and v gad (t) is the expected relative position and expected relative speed of the vehicle-mounted UAV airport relative to the UAV at the next time t+Δt; a2 and b2 are constants.

[0113] The sending unit is used to send the expected position and expected speed of the vehicle-mounted drone airport at the next moment to the displacement controller of the vehicle-mounted drone airport.

[0114] like Figure 4 As shown, according to the relative position relationship between the UAV and the vehicle-mounted UAV airport, the previous position and speed of the two and the expected position and expected speed can be obtained; specifically:

[0115] Calculate the expected distance L between the UAV and the vehicle-mounted UAV field in the x direction x and the expected distance L in the y direction y :

[0116]

[0117] Among them, (x a ,y a ) is the expected position of the following unmanned vehicle (UAV or vehicle-mounted UAV airport), ψ a is the expected navigation angle of the unmanned vehicle behind; (x g ,y g ) is the expected position of the UAV in front (vehicle-mounted UAV airport or UAV), ψ g is the expected navigation angle of the leading UAV;

[0118] Then the expected angle ψ between the two ga for:

[0119]

[0120] By derivation, the error between the expected formation of the UAV and the vehicle-mounted UAV field is:

[0121]

[0122] Among them, (x ad ,y ad ) is the expected relative position of the rear unmanned vehicle relative to the front unmanned vehicle; e1 is the error in the x-direction between the relative position of the rear unmanned vehicle relative to the front unmanned vehicle and the expected relative position; e2 is the error in the y-direction between the relative position of the rear unmanned vehicle relative to the front unmanned vehicle and the expected relative position; e3 is the error in the angle between the rear unmanned vehicle and the front unmanned vehicle and the expected angle;

[0123] By differentiating the error in the above formula, the error model of the desired speed can be obtained:

[0124]

[0125] Among them, v a is the expected speed of the unmanned vehicle behind, v g is the expected speed of the unmanned vehicle ahead, is the expected angular velocity of the unmanned vehicle behind, is the expected angular velocity of the unmanned vehicle in front. d is the expected distance between the UAV and the UAV airport. γ is a calculation factor set to simplify the calculation, γ=ψ ga +ψ g -ψ a . is the differential of e1, is the differential of e2, is the differential of e3.

[0126] Using the above formation control error, the error between the vehicle-mounted UAV airport and the UAV can be close to zero within a limited time. When the vehicle-mounted UAV airport and the UAV are in the desired position, the coordinated control of take-off and landing of the vehicle-mounted UAV airport and the UAV can be achieved.

[0127] It should be noted that although several units or subunits of the device are mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, depending on the embodiment of the application, the features and functions of two or more units described above can be embodied in a single unit. Conversely, the features and functions of a single unit described above can be further divided and embodied by multiple units.

[0128] Furthermore, although the operations of the method of the present application are described in a particular order in the accompanying drawings, this does not require or imply that the operations must be performed in this particular order, or that all illustrated operations must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.

[0129] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of this application and are not intended to limit the scope of the present invention. Although this application has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application and should be encompassed by the claims of this application.

Claims

1. An air-ground coordinated UAV take-off and landing system, characterized in that: include: Vehicle-mounted drone airport, leveling module and coordinated landing module; The vehicle-mounted UAV airport is capable of performing displacement adjustment and attitude adjustment to enable the take-off and landing of the UAV; The leveling module is used to perform leveling control on the vehicle-mounted drone airport to keep the vehicle-mounted drone airport level; The coordinated landing module is used to obtain the position and speed of the vehicle-mounted drone airport and the position and speed of the drone, thereby controlling the movement of the vehicle-mounted drone airport and guiding the landing flight of the drone, thereby achieving coordinated landing of the vehicle-mounted drone airport and the drone; The vehicle-mounted drone airport comprises: a base plate fixed to the vehicle, a helipad, and six adjustable support rods; six first mounting seats (P1, P2, P3, P4, P5, P6) are arranged on the lower surface of the helipad; six second mounting seats (B1, B2, B3, B4, B5, B6) are arranged on the upper surface of the base plate; the support rods comprise first universal joints, electric push rods, and second universal joints, the six first universal joints are respectively fixed on the first mounting seats (P1, P2, P3, P4, P5, P6), and the six second universal joints are respectively fixed on the second mounting seats (B1, B2, B3, B4, B5, B6); The leveling module is specifically used for: Get the extension lengths of the six electric push rods when the apron of the vehicle-mounted drone airport is level; Get the extension length and thrust of the six electric push rods at the current moment; Calculate the difference between the extension length and thrust of each electric push rod at the current moment and the extension length and thrust of each electric push rod when the vehicle-mounted drone airport is horizontal, and obtain 12 deviations; The LQR controller is used to process the 12 deviations to obtain the incremental values ​​of the extension lengths and thrusts of the six electric push rods at the next moment; The extension length of the electric push rods is adjusted by using the incremental values ​​of the extension lengths and the incremental values ​​of the thrust of the six electric push rods; The parameter solution process of the LQR controller includes: Establish the dynamic equations of the vehicle-mounted UAV airport: Among them, m is the load mass of the vehicle-mounted UAV airport, M is the mass of the vehicle-mounted UAV airport, J1, J2, and J3 are the three moments of inertia in the moment of inertia matrix of the airport respectively; ω x ,ω y ,ω z is the angular velocity of the vehicle-mounted UAV airport rotating around the three axes of the absolute coordinate system; ε x ,ε y ,ε z is the angular acceleration of the vehicle-mounted UAV airport around the three axes of the absolute coordinate system; F1(t), F2(t), F3(t), F4(t), F5(t) and F6(t) are the thrusts of the six electric push rods at time t; is the acceleration of the vehicle-mounted UAV airport in the three directions of the absolute coordinate system; g is the gravitational constant; de 1i is the cosine of the X direction of the ith electric push rod in the absolute coordinate system; h 1i is the cosine of the X direction of the i-th electric push rod in the motion coordinate system; de 2i is the cosine of the Y direction of the i-th electric push rod in the absolute coordinate system; h 2i is the cosine of the Y direction of the i-th electric push rod in the motion coordinate system; de 3i is the cosine of the Z direction of the ith electric push rod in the absolute coordinate system; h 3i is the cosine of the Z direction of the i-th electric push rod in the motion coordinate system; According to the above dynamic equations of the vehicle-mounted UAV airport, select As the state quantity of the airport state space equation, after linearization, the state space equation of the vehicle-mounted drone airport can be obtained as: Among them, x, y, z are the three-dimensional coordinates of the vehicle-mounted drone airport in the absolute coordinate system. is the speed of the vehicle-mounted UAV airport in the three directions of the absolute coordinate system, α, β and γ are the roll angle, pitch angle and yaw angle of the vehicle-mounted UAV airport; A is the system matrix, B is the control matrix, C is the output matrix, and D is the direct transfer matrix; u(t) is the 12 deviation quantities; z(t) is the output quantity; According to the cost functional J: Select appropriate matrices Q and R, and calculate the parameters of the LQR controller that constitutes the full state feedback by calculating the optimal solution.

2. The system according to claim 1, wherein: The six first mounting seats (P1, P2, P3, P4, P5, P6) are evenly distributed on the same circle, the radius of the circle is RP, and the six second mounting seats (B1, B2, B3, B4, B5, B6) are evenly distributed on the same circle, the radius of the circle is RB, and the radius RP is smaller than the radius RB.

3. The system according to claim 1, wherein: Get the extension lengths of the six electric push rods at the current moment; including: Get the positions of the six first universal joints of the vehicle-mounted drone airport in the motion coordinate system of the vehicle-mounted drone airport at the current moment; Calculate the positions of the six first gimbals in the absolute coordinate system of the vehicle-mounted drone airport: (x i ,y i ,z i )=H×(x ai ,y ai ,z ai ) Among them, (x i ,y i , z i ) is the three-dimensional coordinate of the i-th first universal joint in the absolute coordinate system of the vehicle-mounted UAV airport, i = 1, 2, 3, 4, 5, 6, (x ai ,y ai , z ai ) is the three-dimensional coordinate of the i-th first universal joint in the motion coordinate system of the vehicle-mounted UAV airport; H is the transformation matrix between the motion coordinate system and the absolute coordinate system of the vehicle-mounted UAV airport; Calculate the extension length of each electric push rod at the vehicle-mounted drone airport: Among them, L i is the extension length of the ith electric push rod; (x bi ,y bi ,z bi ) is the three-dimensional coordinate of the i-th second universal joint in the motion coordinate system of the vehicle-mounted UAV airport.

4. The system according to claim 1, wherein: The collaborative landing module includes: an inertial measurement unit, an RTK unit, a communication unit, a calculation unit and a sending unit; The inertial measurement unit is used to measure the speed of the vehicle-mounted drone at the airport; The RTK unit is used to measure the position of the vehicle-mounted UAV airport; The communication unit is used to communicate data with the drone, obtain the drone's position and speed, and send the drone's expected position and expected speed at the next moment to the drone's flight control system; The calculation unit is used to calculate the expected position and expected speed of the drone at the next moment and the expected position and expected speed of the vehicle-mounted drone airport at the next moment according to the position and speed of the vehicle-mounted drone airport at the current moment, the position and speed of the drone at the current moment, the expected position and expected speed of the preset virtual navigator relative to the drone at the next moment, the expected position and expected speed of the preset virtual navigator relative to the vehicle-mounted drone airport at the next moment, the expected relative position and expected relative speed of the drone relative to the vehicle-mounted drone airport at the next moment, and the expected relative position and expected relative speed of the preset vehicle-mounted drone airport relative to the drone at the next moment, until the position of the drone at the current moment coincides with the position of the vehicle-mounted drone airport at the current moment; The sending unit is used to send the expected position and expected speed of the vehicle-mounted drone airport at the next moment to the displacement controller of the vehicle-mounted drone airport.

5. The system according to claim 4, characterized in that Calculate the expected position and expected speed of the drone at the next moment, including: The expected position and expected speed of the drone at the next moment are: Among them, p ad (t+Δt) and v ad (t+Δt) is the expected position and expected speed of the UAV at the next moment t+Δt; p v (t) and v v (t) is the actual position and actual speed of the virtual navigator at the current time t; p vad (t+Δt) and v vad (t+Δt) is the expected relative position and expected relative speed of the virtual navigator relative to the UAV at the next moment t+Δt; p g (t) and v g (t) is the actual position and actual speed of the vehicle-mounted UAV airport at the current time t; p agd (t+Δt) and v agd (t+Δt) is the expected relative position and expected relative speed of the UAV relative to the vehicle-mounted UAV airport at the next time t+Δt; a1 and b1 are constants.

6. The system according to claim 5, characterized in that Calculate the expected position and expected speed of the vehicle-mounted drone airport at the next moment, including: The expected position and expected speed of the vehicle-mounted drone airport at the next moment are: Among them, p gd (g+Δt) and v gd (t+Δt) is the expected position and expected speed of the vehicle-mounted UAV airport at the next moment t+Δt; p vgd (t) and v vgd (t) is the expected relative position and expected relative speed of the virtual navigator relative to the vehicle-mounted UAV airport at the next time t+Δt; p a (t) and v a (t) is the actual position and actual speed of the UAV at the current time t; p gad (t) and v gad (t) is the expected relative position and expected relative speed of the vehicle-mounted UAV airport relative to the UAV at the next time t+Δt; a2 and b2 are constants.

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