Take-off and landing control system and method for freight unmanned aerial vehicle adopting wings to take off and land

Abstract

The invention discloses a take-off and landing control system and method for a freight unmanned aerial vehicle taking off and landing through wings, and relates to the technical field of freight unmanned aerial vehicle take-off and landing control. A traditional undercarriage structure is omitted, a novel take-off and landing mode with wings as core stress parts is adopted, the structure utilization rate is effectively improved, meanwhile, the corresponding take-off and landing control system and method are provided for the take-off and landing mode, and the constraint of ground take-off and landing places of the unmanned aerial vehicle is reduced. The take-off and landing control system comprises an unmanned aerial vehicle system, a launching system, a recovery system, a control terminal and a positioning module. The vertical constraint requirement of a take-off and landing place is reduced, complex sinking rate-leveling control is converted into simple maintenance of the height H and the level flight cruising speed V, and the safety and adaptability of take-off and landing are improved through precise movement of a ground controllable mechanism.

Description

Technical Field

[0001] This invention relates to the field of cargo drone take-off and landing control technology, specifically to a cargo drone that uses wing take-off and landing, and its take-off and landing control system and method. Background Technology

[0002] Currently, fixed-wing drones typically employ runway takeoff and landing. This method relies on the drone's landing gear, using onboard power to accelerate and take off from the runway. The fixed runway location reduces the deployment flexibility of fixed-wing drones and is unsuitable for efficient deployment in confined spaces. Furthermore, runway-based drones usually require a suitable descent speed to control the vertical load upon landing within a reasonable range. The reinforcement of the landing gear itself and its local structures increases the drone's weight, reducing its payload. Additionally, the exposed landing gear of most drones compromises their aerodynamic performance, which is detrimental to the long-term operation and maintenance of high-frequency logistics drones.

[0003] To simplify structure, reduce weight, and improve operational efficiency, some drone platforms adopt a landing gear-less design. The landing gear-less takeoff and landing method eliminates the complex takeoff and landing structure, which can better optimize the performance of the drone itself. Common landing gear-less takeoff methods include rocket-assisted takeoff, catapult takeoff, air launch, and hand-launched takeoff; corresponding recovery methods include parachute recovery and net-crash recovery. These recovery methods all require manual intervention, making it difficult to promote a highly automated logistics network when facing large-scale drone logistics scenarios in the future, resulting in relatively low efficiency.

[0004] Therefore, there is an urgent need for an efficient take-off and landing method with good automation capabilities to improve the mission operation efficiency of UAVs with take-off and landing without landing gear.

[0005] Some existing concepts involve setting up a ground docking system, in which a ground mobile platform replaces the aircraft landing gear for high-speed taxiing during the take-off and landing phases of the drone. For example, Chinese invention patent application CN118394061A discloses a fixed-wing drone take-off and landing system and landing method based on an intelligent unmanned vehicle. During the drone take-off phase, the intelligent unmanned vehicle is controlled to taxi at high speed. After reaching the drone's take-off speed, the drone is released for take-off. During the drone recovery phase, the intelligent unmanned vehicle actively adjusts its speed and direction to dock with the drone. After successful docking, the drone is carried and decelerated for recovery.

[0006] The patent document discloses a fixed-wing UAV take-off and landing system and landing method based on an intelligent unmanned vehicle, which can effectively ensure the accurate landing of UAVs and improve the efficiency of safe landing. However, this solution is highly dependent on the site, requires the unmanned vehicle to perform long-distance take-off and landing, and involves a large number of control variables, requiring high control precision. Summary of the Invention

[0007] To address the above problems, this invention proposes a cargo drone that uses wing-mounted takeoff and landing, along with its takeoff and landing control system and method. This eliminates the traditional landing gear structure and adopts a novel takeoff and landing mode with the wing as the core load-bearing component, effectively improving structural utilization. At the same time, it provides a corresponding takeoff and landing control system and control method for this takeoff and landing method, reducing the constraints of ground takeoff and landing sites for the drone.

[0008] The technical solution of the present invention is as follows: the take-off and landing control system includes an unmanned aerial vehicle (UAV) system, a launch system, a recovery system, a control terminal, and a positioning module;

[0009] The unmanned aerial vehicle (UAV) system includes a first control unit, a first processor, and a first communication unit installed on the cargo UAV. The first communication unit is used to interact with the control terminal, the launch system, and the recovery system. The first processor processes the data based on the signals from the first communication unit and sends signals to the first control unit to control the cargo UAV to perform corresponding actions.

[0010] The launch system includes a second control unit, a second processor, and a second communication unit installed on the launch device. The second communication unit is used to interact with the control terminal and the UAV system. The second processor feeds back the signal from the second communication unit to the second control unit. The second control unit is responsible for controlling the launch device to launch the cargo UAV.

[0011] The recovery system includes a third control unit, a third processor, and a third communication unit installed on the recovery device. The third communication unit is used to interact with the control terminal and the UAV system. The third processor feeds back the signal from the third communication unit to the third control unit. The third control unit is responsible for controlling the recovery device to receive cargo UAVs.

[0012] Both the recycling device and the cargo drone are equipped with a positioning module, which is used to send the location of the recycling device and the cargo drone to the control terminal.

[0013] The take-off and landing control method for a cargo UAV based on the aforementioned take-off and landing control system includes the following steps:

[0014] Catapult takeoff phase: After the cargo drone is loaded with cargo and installed on the launch device, the second control unit controls the launch device to launch the cargo drone. When the speed sensor in the cargo drone detects that the current speed of the cargo drone has reached the preset speed, the first control unit controls the cargo drone to open the throttle to the maximum.

[0015] During the aerial cruise phase: The cargo drone uses a dual-loop PID control method to maintain its level flight speed and altitude. The dual-loop PID control method includes an airspeed channel and an altitude channel. The outer loop of the airspeed channel is used for airspeed control, and the inner loop is used for propeller speed control in the cargo drone. The outer loop of the altitude channel is used for altitude control, and the inner loop is used for pitch angle control of the cargo drone.

[0016] The first control unit collects the airspeed V and altitude H of the cargo drone in real time, and compares them with the target speed Vref and target altitude Href respectively to form a speed error. Height error The PWM signal command and control surface command required for altitude control of the cargo UAV are calculated using a dual-loop PID control method. This allows the propellers and control surfaces of the cargo drone to work together to maintain stable cruising airspeed and flight altitude.

[0017] Landing and recovery phase: The ground recovery device uses visual sensors based on YOLOv10 drone target recognition technology to identify the cargo drone in flight. The third control unit adjusts the attitude of the robotic arm until the cargo drone is in the center of the visual image acquired by the visual sensor. The positioning module obtains the position of the cargo drone and the recovery device in real time. The first control unit controls the cargo drone to fly toward the recovery device at a preset altitude and speed toward the robotic arm. There is no need to control the descent speed. After being recovered by the recovery device, the cargo drone stops at the designated position.

[0018] The specific control procedures for the catapult launch phase include:

[0019] Step A1: If the cargo drone is mounted, send signal B to the control terminal to display the launch-ready status; otherwise, send signal A to the control terminal to display that it is not mounted.

[0020] Step A2: The second control unit in the launch system receives the ejection command signal from the control terminal and drives the pneumatic ejection device in the launch unit to eject the cargo drone.

[0021] Step A3: If the speed sensor in the cargo drone detects that the current speed of the cargo drone has reached the preset speed, then signal D is sent to the control terminal to display that the launch was successful, and the pneumatic launch device is driven to reset. At the same time, the first control unit controls the cargo drone to keep the throttle fully open; otherwise, signal C is sent to the control terminal to display that the launch was unsuccessful.

[0022] The control process steps for the air cruise phase include:

[0023] Step B1: The first processor on the cargo drone detects whether the speed threshold has reached the speed required for level flight. If it has, the first control unit uses a dual-loop PID control method to control the cargo drone to reach the cruising altitude and maintain the cruising state at the speed required for level flight; otherwise, the cargo drone is kept at full throttle, and the first control unit drives the cargo drone to increase its flight speed.

[0024] Step B2: The cargo drone enters cruise mode and waits for the recovery signal command to be triggered;

[0025] The control method based on dual-loop PID includes an airspeed channel and an altitude channel;

[0026] The airspeed channel is calculated using the following formula:

[0027] The outer ring of the airspeed channel is for airspeed control:

[0028]

[0029]

[0030] In the formula, The target airspeed for cargo drones. This is the current airspeed of the cargo drone. This is the difference between the target airspeed and the current airspeed of the cargo drone. , , These are the proportional, integral, and derivative gain constants for airspeed control, respectively. To calculate the required output thrust;

[0031] The inner loop of the airspeed channel is for speed control, used to control the propellers of cargo drones:

[0032]

[0033]

[0034]

[0035] In the formula, To calculate the required output thrust, It is the gain constant. This refers to the target rotational speed required for the propellers in a cargo drone. This represents the current rotational speed of the propeller in the cargo drone. This represents the difference between the target rotational speed and the current rotational speed of the propeller in a cargo drone. , , These are the proportional, integral, and derivative gain constants for speed control, respectively. The calculated PWM signal command;

[0036] The height channel is calculated using the following formula:

[0037] The outer ring of the height channel is for height control:

[0038]

[0039]

[0040] In the formula, The target altitude for cargo drones, The current altitude of the cargo drone. This represents the difference between the target altitude and the current altitude of the cargo drone. , , These are the proportional, integral, and derivative gain constants for height control, respectively. The required pitch angle for the calculated cargo drone;

[0041] The inner ring of the altitude channel is for the control surfaces of the cargo drone:

[0042]

[0043]

[0044] In the formula, The required output pitch angle for calculating the cargo drone. The current pitch angle of the cargo drone. This is the difference between the required pitch angle for the cargo drone and the current pitch angle. , These are the proportional and derivative gain constants for the control surface, respectively. The calculated control commands for the rudder surfaces.

[0045] The specific control procedures for the landing and recovery phase include:

[0046] Step C1: The first processor detects whether it has received a recovery command from the control terminal. If it is not triggered, the drone maintains its cruise state. Otherwise, the first control unit controls the cargo drone to enter the predetermined recovery altitude and level flight speed, while the third control unit drives the robotic arm to perform attitude control.

[0047] Step C2: Based on the input of positioning module information, the robotic arm follows the cargo drone according to its attitude. At the same time, the first processor calculates the corresponding landing decision window, which has a preset distance from the robotic arm. Then, it checks whether the landing and recovery conditions have been met. The landing and recovery judgment conditions are as follows: if the cargo drone's altitude H1 is within the range of H±∆H2, its level flight speed V is within the range of V1±∆V2, its left and right deviations are within C±∆C, and its attitude deviations are within θ±∆θ, then the recovery conditions have been met and landing can proceed. Otherwise, a signal E is sent to the control terminal to display that the landing and recovery conditions have not been met.

[0048] Step C3: After the landing and recovery conditions are met, if the pressure sensor inside the airbag detects that the cargo drone is in contact with the recovery device, the third processor sends a signal to the first communication unit through the third communication unit. After receiving the signal, the first processor controls the propeller of the cargo drone to stop rotating through the first control unit and sends signal F to the control terminal to display that the recovery is successful. Otherwise, the first control unit controls the cargo drone to continue flying at the recovery altitude and level flight speed.

[0049] The recovery device includes a robotic arm, a secondary buffer recovery device, a base, and a motion track. The motion track is installed on the ground and has damping on its surface. The bottom end of the robotic arm is slidably connected to the motion track via the base, and the actuator of the robotic arm is fixed to the secondary buffer recovery device via a flange connector, thereby driving the secondary buffer recovery device to move arbitrarily in three-dimensional space. The actions of the robotic arm and the secondary buffer recovery device are controlled by a third control unit. A visual sensor for identifying cargo drones is also installed at the middle position of the top surface of the base.

[0050] The launching device includes a catapult frame and a catapult trolley. The rear end of the catapult frame is hinged to the catapult base, and its front end is connected to the catapult base via a hydraulic actuator. The catapult frame is equipped with a pneumatic catapult device for pushing or retrieving the catapult trolley. The pneumatic catapult device is controlled by a second control unit to launch the cargo drone.

[0051] This invention simplifies the takeoff and landing process of unmanned aerial vehicles (UAVs). Unlike other fixed-wing UAVs, this invention shifts the takeoff and landing site from the ground runway to the air. The launch end only needs a catapult rail to accelerate off the ground, and the recovery end uses a combination of a motion rail and a robotic arm to perform clamping and buffering in the air. This eliminates the dependence on runways, interception nets, and large flat areas. Furthermore, the provided takeoff and landing control method for cargo aircraft using wing takeoff and landing reduces the vertical constraints of the takeoff and landing site. It transforms the complex descent rate-leveling control into the simple maintenance of altitude H and level flight cruise speed V. The precise movement of ground-controlled mechanisms improves the safety and adaptability of takeoff and landing.

[0052] The beneficial effects of this invention are as follows:

[0053] I. The cargo drone with wing take-off and landing proposed in this invention can effectively reuse the structure, optimize the aerodynamic performance of the drone while ensuring the effective capacity of the cargo compartment, and make the wing serve as both a lift component and a take-off and landing load-bearing component through local reinforcement of the wing. The traditional landing gear assembly is eliminated in the structure, thereby increasing the effective payload.

[0054] Second, the cargo drone take-off and landing control system and method proposed in this invention can extend the take-off and landing site from the ground to the air, further reduce the vertical constraints of take-off and landing, reduce the amount of drone control over descent speed, and simplify the drone take-off and landing control method.

[0055] Third, the take-off and landing control system and method adopted in this invention can efficiently carry out the automated take-off and landing process of multiple UAVs through a single set of equipment without human intervention, and the take-off and landing system has a certain degree of deployment flexibility, which can enhance the adaptability of take-off and landing sites. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of the cargo drone and its take-off and landing control system;

[0057] Figure 2 This is a diagram of the takeoff and landing control system.

[0058] Figure 3 This is a schematic diagram of the recycling device;

[0059] Figure 4 yes Figure 3 A magnified view of part A in the diagram;

[0060] Figure 5 This is a side view of the recycling unit;

[0061] Figure 6 This is a schematic diagram of the launching device;

[0062] Figure 7 yes Figure 6 A magnified view of part B in the diagram;

[0063] Figure 8 This is a structural diagram of a cargo drone;

[0064] Figure 9 This is a schematic diagram of the wing takeoff and landing contact section of a cargo drone;

[0065] Figure 10 This is a diagram illustrating how a drone lands.

[0066] Figure 11 This is a diagram illustrating the drone's landing process;

[0067] Figure 12 This is a flowchart of the take-off and landing process for cargo drones;

[0068] The labels in the diagram are as follows: 1. Recycling device; 11. Robotic arm; 12. Secondary buffer recycling device; 13. Base; 14. Motion track; 101. Flange connector; 102. Horizontal rib; 103. Mounting connecting column; 104. Longitudinal rib; 105. Linear actuator motor; 106. Support plate; 107. First rotating connector; 108. Second rotating connector; 109. Vertical connecting plate; 110. Sliding component; 111. Fixing component; 112. Clamping plate; 113. Airbag.

[0069] 2. Launching device; 21. Catapult frame; 22. Catapult trolley; 221. Support side plate; 222. Adjustment groove; 223. Wing clamping component; 224. Slide rail.

[0070] 3. Cargo drone, 31. Cargo hull, 35. Wing, 351. Wing take-off and landing contact section, 352. Wing-body blending section, 3511. Leading edge reinforcement, 3512. Reinforcing rib, 3513. Main wing spars. Detailed Implementation

[0071] To clearly illustrate the technical features of the present invention, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0072] like Figure 1 As shown, Figure 1 It includes three main parts: recovery device 1, launch device 2, and cargo drone 3. The relevant features of launch device 2, recovery device 1 and cargo drone 3 are all related to the wings 35 of cargo drone 3, and all of them use wing contact for take-off and landing.

[0073] like Figure 2 As shown, the takeoff and landing control system includes an unmanned aerial vehicle (UAV) system, a launch system, a recovery system, a control terminal, and a positioning module;

[0074] The unmanned aerial vehicle (UAV) system includes a first control unit, a first processor, and a first communication unit installed on the cargo UAV 3. The first communication unit is used to interact with the control terminal, the launch system, and the recovery system. The first processor processes the data based on the signals from the first communication unit and sends signals to the first control unit to control the cargo UAV 3 to perform corresponding actions.

[0075] The launch system includes a second control unit, a second processor, and a second communication unit installed on the launch device 2. The second communication unit is used to interact with the control terminal and the UAV system. The second processor feeds back the signal from the second communication unit to the second control unit. The second control unit is responsible for controlling the launch device 2 to launch the cargo UAV 3.

[0076] The recycling system includes a third control unit, a third processor, and a third communication unit installed on the recycling device 1. The third communication unit is used to interact with the control terminal and the UAV system. The third processor feeds back the signal to the third control unit through the third communication unit. The third control unit is responsible for controlling the receiving cargo UAV 3 of the recycling device 1.

[0077] Both the recycling device 1 and the cargo drone 3 are equipped with positioning modules, which are used to send the location of the recycling device 1 and the cargo drone 3 to the control terminal.

[0078] like Figure 3 , Figure 4 , Figure 5 As shown, the recovery device 1 includes a robotic arm 11, a secondary buffer recovery device 12, a base 13, and a motion track 14. The motion track 14 is installed on the ground, and its surface has damping, enabling ground buffering along the axial direction. The bottom end of the robotic arm 11 is slidably connected to the motion track 14 via the base 13, and the actuator of the robotic arm 11 is fixed to the secondary buffer recovery device 12 via a flange connector, thereby driving the secondary buffer recovery device 12 to move arbitrarily in three-dimensional space. The robotic arm 11 and the secondary buffer recovery device 12 are controlled by a third control unit. A visual sensor for identifying the cargo drone 3 is also installed at the middle position of the top surface of the base 13.

[0079] The secondary buffer recovery device 12 is the drone recovery contact area. It forms a soft contact through the airbag 113, which can reduce the instantaneous overload of the drone. It is also equipped with a rotation damper for further recovery buffering.

[0080] The secondary buffer recovery device 12 includes a flange connector 101, a transverse rib 102, a mounting connecting column 103, a longitudinal rib 104, a linear actuation motor 105, a support plate 106, a first rotating connecting rod 107, a second rotating connecting rod 108, a vertical connecting plate 109, a sliding member 110, a fixing member 111, a clamping plate 112, and an airbag 113.

[0081] The flange connector 101 is fixedly connected to two connecting columns 103 via horizontal ribs 102 on the left and right sides. The horizontal ribs 102 are parallelogram-shaped hollow plates used to strengthen the bearing of longitudinal impact loads. The outer side is connected to the mounting connecting column 103, which is cylindrical. The upper and lower sides of the mounting connecting column 103 are fixedly connected to two fixing plates via longitudinal ribs 104. The front end of the mounting connecting column 103 is fixed to a linear actuator motor 105. The output of the linear actuator motor 105 passes through the support plate 106, which is fixedly connected between the two fixing plates.

[0082] The front end of the fixing plate is hinged to the fixing member 111, and the front end of the fixing member 111 is hinged to the clamping plate 112. The upper and lower sides of the sliding member 110 are simultaneously hinged to two clamping plates 112. The airbag 113 is fixedly installed on the front end face of the sliding member 110. The support plate 106 is connected to the sliding member 110 via the first rotating connecting rod 107 and the second rotating connecting rod 108. The support plate 106, the first rotating connecting rod 107, the second rotating connecting rod 108, and the sliding member 110 are hinged in sequence, and the hinge position has damping.

[0083] The linear actuator 105 can extend and retract along the axial direction. When the slider 110 is translated to the rear, the slider 110 is pushed back to its original position by extending the actuator rod, and a pair of clamping plates 112 are opened.

[0084] The vertical connecting plate 109 is used to support the upper and lower fixed plates, and has a hole in the middle for axial positioning of the sliding member 110. One end of the first rotating member 107 is rotatably connected to the second rotating member 108 through the shaft hole, and the other end of the second rotating member 108 is rotatably connected to the sliding member 110. The connection has damping.

[0085] The front end of the sliding member 110 has a through hole connected to the airbag 113, and the whole can slide along the axial direction. There is a deflection angle between the front end face of the airbag 113 and the sliding member 110, and the deflection angle is adapted to the sweep angle of the wing. The airbag 113 is made of rubber material. The rear of the airbag is connected to the air pump pipeline and the electrically controlled pressure relief valve. Under the control of the controller, the airbag is inflated and deflated, and the internal air pressure can be controlled. The airbag has a pressure sensor module inside, which is used to monitor the internal pressure change of the airbag in real time and generate feedback signals.

[0086] When the recovery device is ready to recover the cargo drone, the wing first contacts the airbag 113. The airbag 113 reduces the instantaneous contact overload by depressurizing, and at the same time pushes the sliding member 110 to slide along the axial direction. At this time, the clamping plate 112 clamps the wing inward under the movement of the sliding member 110. At the same time, when the sliding member 110 translates along the axial direction, it pushes the second rotating connector 108 and the first rotating connector 107. Under the action of damping, the cargo drone is gradually decelerated to a stop. When the recovery device resets, it controls the linear actuation motor 105 to extend along the axial direction, pushing the sliding member 110 to translate outward. At the same time, the two clamping plates 112 rotate and open to the maximum angle. At this time, the secondary buffer recovery device 12 is in the open state.

[0087] like Figure 6 and Figure 7As shown, the launching device 2 includes a catapult frame 21 and a catapult trolley 22. The rear end of the catapult frame 21 is hinged to the catapult base, and its front end is connected to the catapult base via a hydraulic actuator. The launch angle can be adjusted via the hydraulic actuator at the front end. The catapult frame 21 is equipped with a pneumatic catapult device for pushing or retrieving the catapult trolley 22. The pneumatic catapult device in this case uses an existing mechanism, which will not be described in detail here. Thus, the catapult trolley 22 is launched using a pneumatic catapult method, while the catapult base is supported on the ground by four legs. During operation, the second communication unit receives command signals from the control terminal and simultaneously feeds back the latest status of the launching device. The second processor feeds back the signals from the second communication unit to the second control unit, which then controls the pneumatic catapult device to launch the cargo drone 3.

[0088] The catapult trolley 22 is equipped with a support side plate 221, a wing clamping member 223 and a slide rail 224. The catapult trolley 22 is mounted on the catapult frame 21 by pulleys. A pair of support side plates 221 are detachably mounted at both ends of the top surface of the catapult trolley 22, and the wing clamping member 223 is welded to the upper part of them, which can temporarily fix the cargo drone according to the shape of the wing.

[0089] The catapult trolley 22 is also provided with several parallel adjustment slots 222. The slide rail 224 is fixedly installed on the top surface of the catapult trolley 22 and is perpendicular to the support side plate 221. The bottom of the support side plate 221 is provided with a slot adapted to the slide rail 224 and an insert adapted to the adjustment slot 222. Thus, the width of the two support side plates 221 can be adjusted by inserting into the adjustment slots at different positions below to accommodate cargo drones with different wingspans.

[0090] like Figure 8 and Figure 9 As shown, the cargo drone 3 includes a cargo cabin 31 and a wing 35. The cargo drone 3 is a type of high aspect ratio fixed-wing drone. The wing 35 adopts a high-wing configuration and a streamlined overall shape. The wing-body blending structure is optimized, and the traditional landing gear assembly is eliminated in the structure, effectively freeing up the belly space for embedding the modular cargo cabin 31.

[0091] The cargo compartment 31 is embedded in the belly of the cargo drone 3. The compartment is a modular and replaceable structure. The side and bottom contours are consistent with the belly of the cargo drone 3, so as to minimize flight drag while achieving high-density cargo carrying.

[0092] like Figure 9As shown, the wing 35 includes a blended wing-body section 352 and a wing takeoff and landing contact section 351. It serves as both a lift component and a load-bearing component for the cargo drone 3 during takeoff and landing. The blended wing-body section 352 is located in the transition area between the wing and the fuselage. As a blended wing-body structure, it optimizes the aerodynamic shape of the cargo drone. At the same time, it has reinforcing ribs and main wing spars extended sections inside to withstand the high-intensity loads generated during takeoff and landing, such as takeoff acceleration and landing impact. Its outer side connects to the wing takeoff and landing contact section 351.

[0093] The wing landing contact section 351 includes a leading edge reinforcement 3511, a reinforcing rib 3512, and a main wing sparsity 3513, which are used to form a high-strength mechanical engagement with the ground landing device clamps. The leading edge reinforcement 3511 is made of a metal core block, and its outer skin is covered with high-strength carbon fiber composite material to enhance local strength and withstand the longitudinal impact load during recovery. The main wing sparsity 3513 serves as the main load-bearing component of the wing 35. The inner side of the main wing sparsity 3513 is connected to the wing-body fusion section 352. The main wing sparsity 3513 is fixed to the middle part of the wing landing contact section 351, and it is also connected to the leading edge reinforcement 3511 through the reinforcing rib 3512.

[0094] like Figure 10 and Figure 11 As shown, the cargo drone adopts a new take-off and landing mode using wing take-off and landing. The core of this mode is to change the take-off and landing site from the ground runway to the air and to change the take-off and landing components from the traditional landing gear to the wing-borne take-off and landing. By reducing the vertical constraints on the ground during landing and reducing the impact of the sinking speed, the vertical overload of take-off and landing is converted into longitudinal overload, thereby simplifying the take-off and landing control of the cargo drone. This allows the cargo drone to only control the level flight speed V and the level flight altitude H.

[0095] like Figure 12 As shown, the takeoff and landing control method for a cargo UAV using wing takeoff and landing includes the following steps:

[0096] Catapult takeoff phase: After the cargo drone 3 is loaded with cargo and installed on the launch device 2, the second control unit controls the launch device 2 to launch the cargo drone 3. When the speed sensor in the cargo drone 3 detects that the current speed of the cargo drone 3 has reached the preset speed, the first control unit controls the cargo drone 3 to fully open the throttle.

[0097] During the aerial cruise phase: The cargo drone 3 maintains its level flight cruise speed and altitude using a dual-loop PID control method. The dual-loop PID control method includes an airspeed channel and an altitude channel. The outer loop of the airspeed channel is used for airspeed control, and the inner loop is used for propeller speed control in the cargo drone. The outer loop of the altitude channel is used for altitude control, and the inner loop is used for pitch angle control of the cargo drone.

[0098] The first control unit collects the airspeed V and altitude H of the cargo drone in real time, and compares them with the target speed Vref and target altitude Href respectively to form a speed error. Height error The PWM signal command and control surface command required for altitude control of the cargo UAV are calculated using a dual-loop PID control method. This allows the propellers and control surfaces of the cargo drone to work together to maintain stable cruising airspeed and flight altitude.

[0099] Landing and recovery phase: The ground recovery device 1 uses a visual sensor based on YOLOv10 cargo drone target recognition technology to identify the cargo drone 3 flying in the air. The third control unit adjusts the attitude of the robotic arm 11 until the cargo drone 3 is in the center of the visual image acquired by the visual sensor. The positioning module obtains the position of the cargo drone and the recovery device in real time. The first control unit controls the cargo drone to fly towards the recovery device at a preset height and speed toward the robotic arm. There is no need to control the descent speed. After being recovered by the recovery device, the cargo drone stops at the designated position.

[0100] like Figure 12 As shown, the control steps of this embodiment provide a specific takeoff and landing process control method, including the following:

[0101] The specific control procedures for the catapult launch phase include:

[0102] Step A1: If the cargo drone is mounted, send signal B to the control terminal to display the launch-ready status; otherwise, send signal A to the control terminal to display that it is not mounted.

[0103] Step A2: The second control unit in the launch system receives the ejection command signal from the control terminal and drives the pneumatic ejection device in the launch unit to eject the cargo drone.

[0104] Step A3: If the speed sensor in cargo drone 3 detects that the current speed of cargo drone 3 has reached the preset speed, then signal D is sent to the control terminal to display that the launch was successful, and the pneumatic launch device is driven to reset. At the same time, the first control unit controls the cargo drone to keep the throttle fully open; otherwise, signal C is sent to the control terminal to display that the launch was unsuccessful.

[0105] The control process steps for the air cruise phase include:

[0106] Step B1: The first processor on the cargo drone detects whether the speed threshold has reached the speed required for level flight. If it has, the first control unit uses a dual-loop PID control method to control the cargo drone to reach the cruising altitude and maintain the cruising state at the speed required for level flight; otherwise, the cargo drone is kept at full throttle, and the first control unit drives the cargo drone to increase its flight speed.

[0107] Step B2: The cargo drone enters cruise mode and waits for the recovery signal command to be triggered;

[0108] The airspeed channel is calculated using the following formula:

[0109] The outer ring of the airspeed channel is for airspeed control:

[0110]

[0111]

[0112] In the formula, The target airspeed for cargo drones. This is the current airspeed of the cargo drone. This is the difference between the target airspeed and the current airspeed of the cargo drone. , , These are the proportional, integral, and derivative gain constants for airspeed control, respectively. To calculate the required output thrust;

[0113] The inner loop of the airspeed channel is for speed control, used to control the propellers of cargo drones:

[0114]

[0115]

[0116]

[0117] In the formula, To calculate the required output thrust, It is the gain constant. This refers to the target rotational speed required for the propellers in a cargo drone. This represents the current rotational speed of the propeller in the cargo drone. This represents the difference between the target rotational speed and the current rotational speed of the propeller in a cargo drone. , , These are the proportional, integral, and derivative gain constants for speed control, respectively. The calculated PWM signal command;

[0118] The height channel is calculated using the following formula:

[0119] The outer ring of the height channel is for height control:

[0120]

[0121]

[0122] In the formula, The target altitude for cargo drones, The current altitude of the cargo drone. This represents the difference between the target altitude and the current altitude of the cargo drone. , , These are the proportional, integral, and derivative gain constants for height control, respectively. The required pitch angle for the calculated cargo drone;

[0123] The inner ring of the altitude channel is for the control surfaces of the cargo drone:

[0124]

[0125]

[0126] In the formula, The required output pitch angle for calculating the cargo drone. The current pitch angle of the cargo drone. This is the difference between the required pitch angle for the cargo drone and the current pitch angle. , These are the proportional and derivative gain constants for the control surface, respectively. The calculated control commands for the rudder surfaces.

[0127] The specific control procedures for the landing and recovery phase include:

[0128] Step C1: The first processor detects whether it has received a recovery command from the control terminal. If it is not triggered, the drone maintains its cruise state. Otherwise, the first control unit controls the cargo drone to enter the predetermined recovery altitude and level flight speed, while the third control unit drives the robotic arm to perform attitude control.

[0129] Step C2: Based on the input of positioning module information, the robotic arm follows the cargo drone according to its attitude. At the same time, the first processor calculates the corresponding landing decision window, which has a preset distance from the robotic arm. Then, it checks whether the landing and recovery conditions have been met. The landing and recovery judgment conditions are as follows: if the cargo drone's altitude H1 is within the range of H±∆H2, its level flight speed V is within the range of V1±∆V2, its left and right deviations are within C±∆C, and its attitude deviations are within θ±∆θ, then the recovery conditions have been met and landing can proceed. Otherwise, a signal E is sent to the control terminal to display that the landing and recovery conditions have not been met.

[0130] Step C3: After the landing and recovery conditions are met, if the pressure sensor inside the airbag detects that the cargo drone is in contact with the recovery device, the third processor sends a signal to the first communication unit through the third communication unit. After receiving the signal, the first processor controls the propeller of the cargo drone to stop rotating through the first control unit and sends signal F to the control terminal to display that the recovery is successful. Otherwise, the first control unit controls the cargo drone to continue flying at the recovery altitude and level flight speed.

[0131] It should be noted that the specific locations of the control unit, processor, and communication unit mentioned above are not shown in the attached diagram. Users can install them in the appropriate locations according to their specific application requirements. The installation and connection locations of the sensors mentioned can also be placed according to specific application requirements.

[0132] There are many specific ways to implement this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A take-off and landing control system for a cargo drone employing wing take-off and landing, characterized in that, The take-off and landing control system includes an unmanned aerial vehicle (UAV) system, a launch system, a recovery system, a control terminal, and a positioning module. The unmanned aerial vehicle (UAV) system includes a first control unit, a first processor, and a first communication unit installed on the cargo UAV. The first communication unit is used to interact with the control terminal, the launch system, and the recovery system. The first processor processes the data based on the signals from the first communication unit and sends signals to the first control unit to control the cargo UAV to perform corresponding actions. The launch system includes a second control unit, a second processor, and a second communication unit installed on the launch device. The second communication unit is used to interact with the control terminal and the UAV system. The second processor feeds back the signal from the second communication unit to the second control unit. The second control unit is responsible for controlling the launch device to launch the cargo UAV. The recovery system includes a third control unit, a third processor, and a third communication unit installed on the recovery device. The third communication unit is used to interact with the control terminal and the UAV system. The third processor feeds back the signal from the third communication unit to the third control unit. The third control unit is responsible for controlling the recovery device to receive cargo UAVs. Both the recycling device and the cargo drone are equipped with a positioning module, which is used to send the location of the recycling device and the cargo drone to the control terminal.

2. A take-off and landing control method for a cargo UAV based on the take-off and landing control system of claim 1, characterized in that, Includes the following steps: Catapult takeoff phase: After the cargo drone is loaded with cargo and installed on the launch device, the second control unit controls the launch device to launch the cargo drone. When the speed sensor in the cargo drone detects that the current speed of the cargo drone has reached the preset speed, the first control unit controls the cargo drone to open the throttle to the maximum. During the aerial cruise phase: The cargo drone uses a dual-loop PID control method to maintain its level flight speed and altitude. The dual-loop PID control method includes an airspeed channel and an altitude channel. The outer loop of the airspeed channel is used for airspeed control, and the inner loop is used for propeller speed control in the cargo drone. The outer loop of the altitude channel is used for altitude control, and the inner loop is used for pitch angle control of the cargo drone. The first control unit collects the airspeed V and altitude H of the cargo drone in real time, and compares them with the target speed Vref and target altitude Href respectively to form a speed error. Height error The PWM signal command and control surface command required for altitude control of the cargo UAV are calculated using a dual-loop PID control method. This allows the propellers and control surfaces of the cargo drone to work together to maintain stable cruising airspeed and flight altitude. Landing and recovery phase: The ground recovery device uses visual sensors based on YOLOv10 drone target recognition technology to identify the cargo drone in flight. The third control unit adjusts the attitude of the robotic arm until the cargo drone is in the center of the visual image acquired by the visual sensor. The positioning module obtains the position of the cargo drone and the recovery device in real time. The first control unit controls the cargo drone to fly toward the recovery device at a preset altitude and speed toward the robotic arm. There is no need to control the descent speed. After being recovered by the recovery device, the cargo drone stops at the designated position.

3. The take-off and landing control method for a cargo drone according to claim 2, characterized in that, The specific control procedures for the catapult launch phase include: Step A1: If the cargo drone is mounted, send signal B to the control terminal to display the launch-ready status; otherwise, send signal A to the control terminal to display that it is not mounted. Step A2: The second control unit in the launch system receives the ejection command signal from the control terminal and drives the pneumatic ejection device in the launch unit to eject the cargo drone. Step A3: If the speed sensor in the cargo drone detects that the current speed of the cargo drone has reached the preset speed, then signal D is sent to the control terminal to display that the launch was successful, and the pneumatic launch device is driven to reset. At the same time, the first control unit controls the cargo drone to keep the throttle fully open; otherwise, signal C is sent to the control terminal to display that the launch was unsuccessful.

4. The take-off and landing control method for a cargo drone according to claim 2, characterized in that, The control process steps for the air cruise phase include: Step B1: The first processor on the cargo drone detects whether the speed threshold has reached the speed required for level flight. If it has, the first control unit uses a dual-loop PID control method to control the cargo drone to reach the cruising altitude and maintain the cruising state at the speed required for level flight; otherwise, the cargo drone is kept at full throttle, and the first control unit drives the cargo drone to increase its flight speed. Step B2: The cargo drone enters cruise mode and waits for the recovery signal command to be triggered; The control method based on dual-loop PID includes an airspeed channel and an altitude channel; The airspeed channel is calculated using the following formula: The outer ring of the airspeed channel is for airspeed control: ； ； In the formula, The target airspeed for cargo drones. This is the current airspeed of the cargo drone. This is the difference between the target airspeed and the current airspeed of the cargo drone. , , These are the proportional, integral, and derivative gain constants for airspeed control, respectively. To calculate the required output thrust; The inner loop of the airspeed channel is for speed control, used to control the propellers of cargo drones: ； ； ； In the formula, To calculate the required output thrust, It is the gain constant. The propellers required for cargo drones The target speed achieved, This represents the current rotational speed of the propeller in the cargo drone. This represents the difference between the target rotational speed and the current rotational speed of the propeller in a cargo drone. , , These are the proportional, integral, and derivative gain constants for speed control, respectively. The calculated PWM signal command; The height channel is calculated using the following formula: The outer ring of the height channel is for height control: ； ； In the formula, The target altitude for cargo drones, The current altitude of the cargo drone. This represents the difference between the target altitude and the current altitude of the cargo drone. , , These are the proportional, integral, and derivative gain constants for height control, respectively. The required pitch angle for the calculated cargo drone; The inner ring of the altitude channel is for the control surfaces of the cargo drone: ； ； In the formula, The required output pitch angle for calculating the cargo drone. The current pitch angle of the cargo drone. This is the difference between the required pitch angle for the cargo drone and the current pitch angle. , These are the proportional and derivative gain constants for the control surface, respectively. The calculated control commands for the rudder surfaces.

5. The take-off and landing control method for a cargo drone according to claim 2, characterized in that, The specific control procedures for the landing and recovery phase include: Step C1: The first processor detects whether it has received a recovery command from the control terminal. If it is not triggered, the drone maintains its cruise state. Otherwise, the first control unit controls the cargo drone to enter the predetermined recovery altitude and level flight speed, while the third control unit drives the robotic arm to perform attitude control. Step C2: Based on the input of positioning module information, the robotic arm follows the cargo drone according to its attitude. At the same time, the first processor calculates the corresponding landing decision window, which has a preset distance from the robotic arm. Then, it checks whether the landing and recovery conditions have been met. The landing and recovery judgment conditions are as follows: if the cargo drone's altitude H1 is within the range of H±∆H2, its level flight speed V is within the range of V1±∆V2, its left and right deviations are within C±∆C, and its attitude deviations are within θ±∆θ, then the recovery conditions have been met and landing can proceed. Otherwise, a signal E is sent to the control terminal to display that the landing and recovery conditions have not been met. Step C3: After the landing and recovery conditions are met, if the pressure sensor inside the airbag detects that the cargo drone is in contact with the recovery device, the third processor sends a signal to the first communication unit through the third communication unit. After receiving the signal, the first processor controls the propeller of the cargo drone to stop rotating through the first control unit and sends signal F to the control terminal to display that the recovery is successful. Otherwise, the first control unit controls the cargo drone to continue flying at the recovery altitude and level flight speed.

6. The take-off and landing control system for a cargo UAV employing wing take-off and landing as described in claim 1, characterized in that, The recovery device includes a robotic arm, a secondary buffer recovery device, a base, and a motion track. The motion track is installed on the ground and has damping on its surface. The bottom end of the robotic arm is slidably connected to the motion track via the base, and the actuator of the robotic arm is fixed to the secondary buffer recovery device via a flange connector, thereby driving the secondary buffer recovery device to move arbitrarily in three-dimensional space. The actions of the robotic arm and the secondary buffer recovery device are controlled by a third control unit. A visual sensor for identifying cargo drones is also installed at the middle position of the top surface of the base.

7. The take-off and landing control system for a cargo UAV employing wing take-off and landing as described in claim 1, characterized in that, The launching device includes a catapult frame and a catapult trolley. The rear end of the catapult frame is hinged to the catapult base, and its front end is connected to the catapult base via a hydraulic actuator. The catapult frame is equipped with a pneumatic catapult device for pushing or retrieving the catapult trolley. The pneumatic catapult device is controlled by a second control unit to launch the cargo drone.

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