A method and system for recovering a UAV, a ground station system, and a UAV

Abstract

The application discloses a kind of unmanned plane recycling methods, comprising the following steps: ground station system obtains the position information of fixed-wing unmanned plane, keeps the flight state of fixed-wing unmanned plane, and issues take-off instruction to multi-rotor unmanned plane;Multi-rotor unmanned plane tracks the navigation point of fixed-wing unmanned plane, shortens the relative distance between multi-rotor unmanned plane and fixed-wing unmanned plane;Adjust the flight parameters of multi-rotor unmanned plane, keep the distance difference of multi-rotor unmanned plane and fixed-wing unmanned plane in height direction;Adjust the relative motion distance between multi-rotor unmanned plane and fixed-wing unmanned plane, and carry out docking recycling;Close the power system of fixed-wing unmanned plane, control multi-rotor unmanned plane to land to preset place.The application can well utilize multi-rotor unmanned plane to realize the recycling of fixed-wing unmanned plane in the air.The application also discloses a kind of unmanned plane recycling system, ground station system, unmanned plane.

Description

Technical Field

[0001] This invention belongs to the field of drone recovery technology, and particularly relates to a drone recovery method and system, a ground station system, and a drone. Background Technology

[0002] The main recovery methods for small fixed-wing drones currently available include net recovery, trolley recovery, "skyhook" recovery, and parachute recovery. All of these methods are limited by the recovery site, the recovery environment, and the risk of damage.

[0003] For compound-wing UAVs, the vertical take-off and landing method inevitably has problems such as the vertical take-off and landing structure affecting aerodynamics and increasing structural weight. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention discloses a method and system for recovering unmanned aerial vehicles (UAVs), a ground station system, and the UAV itself, which effectively utilizes multi-rotor UAVs to recover fixed-wing UAVs in mid-air. The specific technical solution of this invention is as follows:

[0005] In a first aspect, the present invention discloses a method for recovering a drone in mid-air, comprising the following steps:

[0006] The method for recovering a fixed-wing drone from a multi-rotor drone in mid-air includes the following steps:

[0007] The ground station system acquires the position information of the fixed-wing UAV, maintains the flight status of the fixed-wing UAV, and issues takeoff commands to the multi-rotor UAV.

[0008] Multi-rotor drones can track the navigation points of fixed-wing drones, thereby reducing the relative distance between the two drones.

[0009] Adjust the flight parameters of the multi-rotor drone to maintain the distance difference between the multi-rotor drone and the fixed-wing drone in the altitude direction;

[0010] Adjust the relative movement distance between the multi-rotor drone and the fixed-wing drone for docking and recovery;

[0011] Turn off the power system of the fixed-wing drone and control the multi-rotor drone to land at the preset location.

[0012] Secondly, the present invention discloses a control device, comprising:

[0013] Memory, used to store program instructions; and

[0014] The processor is used to call programs stored in memory to perform the following steps:

[0015] Acquire the position information of the fixed-wing UAV, maintain the flight status of the fixed-wing UAV, and issue take-off commands to the multi-rotor UAV;

[0016] This enables multi-rotor drones to track the navigation points of fixed-wing drones, thereby reducing the relative distance between the two types of drones.

[0017] Adjust the flight parameters of the multi-rotor drone to maintain the distance difference between the multi-rotor drone and the fixed-wing drone in the altitude direction;

[0018] Adjust the relative movement distance between the multi-rotor drone and the fixed-wing drone for docking and recovery;

[0019] Turn off the power system of the fixed-wing drone and control the multi-rotor drone to land at the preset location.

[0020] Thirdly, the present invention discloses a control device, comprising:

[0021] Memory, used to store program instructions; and

[0022] The processor is used to call programs stored in memory to perform the following steps:

[0023] Receive control commands from the ground station system;

[0024] Respond to control commands and maintain flight status;

[0025] After completing the aerial docking, shut down the power system.

[0026] Fourthly, the present invention discloses a control device, comprising:

[0027] Memory, used to store program instructions; and

[0028] The processor is used to call programs stored in memory to perform the following steps:

[0029] Receive control commands from the ground station system;

[0030] In response to control commands, it takes off and approaches the fixed-wing drone that needs to be recovered;

[0031] After completing the aerial docking, land at the designated location.

[0032] Fifthly, the present invention discloses a ground station system, including a control device as described in the second aspect.

[0033] Sixthly, the present invention discloses a fixed-wing unmanned aerial vehicle, comprising:

[0034] body;

[0035] The power system, located on the fuselage, is used to propel the fixed-wing drone into flight; and

[0036] A control device as described in the third aspect;

[0037] The fuselage has a docking visual identification surface at the bottom of its belly center of gravity, and the docking visual identification surface has a spherical locking hook.

[0038] In a seventh aspect, the present invention discloses a multi-rotor unmanned aerial vehicle, comprising:

[0039] body;

[0040] The power system, located within the fuselage, propels the multi-rotor drone; and

[0041] A control device as described in the fourth aspect;

[0042] The top of the fuselage is provided with a locking slot, and a distance measuring sensor is provided in the locking slot; a vision sensor is provided on one side of the locking slot.

[0043] Eighthly, the present invention discloses a drone recovery system, comprising:

[0044] Fixed-wing drones are used for aerial recovery after completing their flight missions.

[0045] Multi-rotor drones are used to dock with fixed-wing drones in mid-air, enabling the recovery of the fixed-wing drones; and

[0046] The ground station system is used to acquire the position of fixed-wing UAVs, issue control commands to fixed-wing UAVs and multi-rotor UAVs; control fixed-wing UAVs to maintain flight status; control multi-rotor UAVs to take off and approach fixed-wing UAVs; and control multi-rotor UAVs to dock with fixed-wing UAVs.

[0047] The ground station system is also used to shut down the power system of the fixed-wing UAV after it docks with the multi-rotor UAV, and to instruct the multi-rotor UAV to carry the fixed-wing UAV to a preset location.

[0048] In a ninth aspect, the present invention discloses a computer-readable storage medium storing a computer program that, when executed by a processor, implements the over-the-air recovery method as described in the first aspect.

[0049] Compared with existing technologies, this invention utilizes multi-rotor UAVs to recover fixed-wing UAVs, reducing the requirements of fixed-wing UAVs for landing environments. It can not only achieve landings on ships, in environments with many trees and forests, and in densely built-up environments, but also ensure more precise recovery locations and faster and more convenient use. Compared with compound wing vertical take-off and landing UAVs, it increases the flight performance and endurance of mission-oriented fixed-wing UAVs. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the drone recovery system in an embodiment of the present invention;

[0051] Figure 2 This is a flowchart illustrating the drone recovery method in an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of the control method of the ground station system in an embodiment of the present invention;

[0053] Figure 4 This is a schematic flowchart of the control method for a fixed-wing unmanned aerial vehicle in an embodiment of the present invention;

[0054] Figure 5 This is a schematic diagram of the control method for a multi-rotor unmanned aerial vehicle in an embodiment of the present invention;

[0055] Figure 6 This is a schematic diagram of the state in one direction during the docking of the UAV in an embodiment of the present invention;

[0056] Figure 7 This is a schematic diagram of the state from another direction during the docking of the UAVs in an embodiment of the present invention;

[0057] Figure 8 This is a schematic diagram of a multi-rotor drone in an embodiment of the present invention;

[0058] Figure 9 This is a schematic diagram of the mating groove arrangement in an embodiment of the present invention.

[0059] In the diagram: 1-First fuselage; 2-Dating visual identification surface; 3-Locking hook; 4-Second fuselage; 5-Locking slot; 6-Distance sensor; 7-Visual sensor; 8-Matching slot; 9-Rotor arm; 10-Elastic arresting cable; 11-First link; 12-Second link; 13-Sleeve; 14-Third link; 15-Propeller. Detailed Implementation

[0060] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to specific embodiments.

[0061] like Figure 1As shown in this embodiment, a drone recovery method is used to recover a fixed-wing drone in the air. Specifically, the method is applied to a drone recovery system, including a fixed-wing drone, a multi-rotor drone, and a ground station system. When the fixed-wing drone completes its flight mission, the ground station system controls the flight of both the fixed-wing and multi-rotor drones, enabling them to dock and lock together. Then, the multi-rotor drone carries the fixed-wing drone to a preset location, thereby achieving the goal of recovering the fixed-wing drone.

[0062] In the aforementioned drone recovery system, both the fixed-wing drone and the ground station system, and the multi-rotor drone and the ground station system, have wireless communication connections. In this embodiment, the wireless communication is achieved via radio waves; however, the wireless communication can also be implemented through a third party, such as a cloud platform.

[0063] For fixed-wing UAVs, there is a locking hook 3; for multi-rotor UAVs, there is a locking groove 5. The locking hook 3 can extend into the locking groove 5, and the locking groove 5 locks the locking hook 3. It can be understood that the locking groove 5 is a self-locking groove. When the locking hook 3 extends into the locking groove 5, the groove automatically locks, thereby realizing the docking between the two UAVs and achieving a locked posture.

[0064] Therefore, in this embodiment, the implementation of the UAV recovery method should be based on the UAV recovery system, that is, the recovery of fixed-wing UAVs, which is achieved through the cooperation between fixed-wing UAVs, multi-rotor UAVs and ground station systems.

[0065] like Figure 2 As shown, based on this, this embodiment discloses a method for recovering a drone in mid-air, which includes the following steps:

[0066] S101, the ground station system acquires the position information of the fixed-wing UAV, maintains the flight status of the fixed-wing UAV, and issues take-off commands to the multi-rotor UAV.

[0067] After a fixed-wing UAV completes its mission, it needs to be recovered. Since landing a fixed-wing UAV requires specific conditions regarding the landing site and environment, this embodiment utilizes a multi-rotor UAV for recovery. Specifically, when the fixed-wing UAV is ready to land, the ground station system obtains its location information via wireless communication, transmits a command to maintain flight status, and simultaneously instructs the multi-rotor UAV to take off and fly towards the fixed-wing UAV's location, thus fulfilling the prerequisite for docking between the fixed-wing and multi-rotor UAVs.

[0068] S102. Multi-rotor UAVs track the navigation points of fixed-wing UAVs, shortening the relative distance between the two.

[0069] It should be explained here that both the fixed-wing UAV and the multi-rotor UAV have a positioning and navigation system. After the fixed-wing UAV transmits the navigation point to the ground station system, the ground station system forwards the navigation point to the multi-rotor UAV. Thus, the multi-rotor UAV calculates the navigation point and navigates to the corresponding coordinate point. This process is a continuous and iterative process until the multi-rotor UAV and the fixed-wing UAV are at a first preset distance apart.

[0070] That is, after the fixed-wing UAV completes its flight mission, it needs to land nearby. The ground station system controls the multi-rotor UAV to take off and follow the current navigation point issued by the fixed-wing UAV. When the multi-rotor UAV tracks the first navigation point of the fixed-wing UAV, the fixed-wing UAV immediately issues the next navigation point. This continues until the spatial coordinates between the fixed-wing UAV and the multi-rotor UAV are at a first preset distance, thus completing the first stage of docking control.

[0071] Understandably, the above process can also be successful in one go, that is, after one operation, the multi-rotor drone and the fixed-wing drone are placed at a first preset distance.

[0072] S103. Adjust the flight parameters of the multi-rotor UAV to maintain the distance difference between the multi-rotor UAV and the fixed-wing UAV in the altitude direction.

[0073] When the distance between the multi-rotor drone and the fixed-wing drone is the first preset distance, the multi-rotor drone needs to be positioned below the fixed-wing drone to meet the docking prerequisite for the second stage.

[0074] Therefore, after adjusting the flight parameters of the multi-rotor UAV, in the most ideal state, the multi-rotor UAV is located directly below the fixed-wing UAV. At this time, the extended line of the central axis of the locking hook 3 and the extended line of the central axis of the locking groove 5 are located on the same straight line perpendicular to the horizontal plane.

[0075] It should be noted that the above flight parameters include at least one of flight speed, flight direction, and flight angle.

[0076] S104. Adjust the relative movement distance between the multi-rotor UAV and the fixed-wing UAV for docking and recovery.

[0077] Once the distance between the multi-rotor drone and the fixed-wing drone is reduced, the two drones eventually achieve a stable docking and lock-on, thus realizing the second stage of docking and enabling the recovery of the fixed-wing drone.

[0078] S105. Turn off the power system of the fixed-wing UAV and control the multi-rotor UAV to land at the preset location.

[0079] In this embodiment, after the fixed-wing UAV and the multi-rotor UAV successfully dock, the power system of the fixed-wing UAV needs to be turned off. The power system of the multi-rotor UAV is used to drive the multi-rotor UAV to carry the fixed-wing UAV and finally land at the preset location, thereby realizing the complete recovery of the fixed-wing UAV.

[0080] To better utilize this embodiment, the ground station system controls the multi-rotor UAV to approach the fixed-wing UAV via formation commands.

[0081] Drone formation commands require coordinated action between the drones and the ground station system. After the ground station system issues the formation command, it controls the drones to perform the prescribed flight maneuvers, with positioning being the core element. Therefore, after the ground station system obtains the position information of the fixed-wing drones, it communicates this information to the multi-rotor drones, instructing them to move to the designated location. It's understandable that during the recovery process of the fixed-wing drones, their positions constantly change, requiring them to continuously send position information to the ground station system, or at regular intervals. During this process, the multi-rotor drones continuously adjust their intended location, either by reaching one location before moving to the next. This allows the multi-rotor drones to converge with the fixed-wing drones.

[0082] To better utilize this embodiment, the following steps are also included:

[0083] S1041. When the fixed-wing UAV enters the visual capture range of the multi-rotor UAV, the ground station system switches the coordinate navigation control provided by the formation command to visual laser navigation control, so that the docking visual marker 2 of the fixed-wing UAV is in the position of docking with the multi-rotor UAV.

[0084] As explained above, the core of formation commands is positioning, enabling multi-rotor drones to approach fixed-wing drones. Typically, a virtual altitude, such as 5 meters, can be added to the navigation commands within the formation command program. Thus, when the altitude difference between the multi-rotor and fixed-wing drones is 0 meters, it indicates that the actual distance between them is 5 meters. At this point, the fixed-wing drone enters the visual capture range of the multi-rotor drone and switches its navigation commands to visual laser navigation. During this process, distance sensors are used to calculate the relative distance between the multi-rotor and fixed-wing drones in real time, maintaining the actual distance between them at 5 meters.

[0085] It is understandable that both multi-rotor and fixed-wing UAVs achieve positioning in a ground-based inertial coordinate system. Therefore, after the distance sensor of the multi-rotor UAV provides feedback on the relative distance, the ground station system continuously adjusts the flight parameters of the multi-rotor UAV to reduce the relative altitude between the multi-rotor and fixed-wing UAVs. Thus, when the relative motion is stable and the difference in relative motion is less than the acceptable range for docking, the ground station system can control the multi-rotor UAV to further reduce the spatial difference with the fixed-wing UAV according to the ground-based inertial coordinate system, thereby achieving docking between the multi-rotor and fixed-wing UAVs.

[0086] To better utilize this embodiment, during the process of adjusting the relative movement distance between the multi-rotor drone and the fixed-wing drone, the locking slot 5 of the multi-rotor drone is aligned and docked with the locking hook 3 of the fixed-wing drone.

[0087] In this embodiment, the multi-rotor UAV has a locking groove 5, and the fixed-wing UAV has a locking hook 3. When the locking hook 3 extends into the locking groove 5, the locking groove 5 utilizes its self-locking characteristic to lock the fixed-wing UAV through the locking hook 3. The locking groove 5, which has a self-locking characteristic, contains a locking tongue device that can engage the locking hook 3. Specifically, when the locking hook 3 contacts the locking tongue device and the locking hook 3 continues to extend into the locking groove 5, the locking tongue device will move. After the movement is complete, the locking hook 3 can be fully extended into the locking groove 5. At this time, the locking tongue device resets, thus achieving the locking of the locking hook 3.

[0088] To better utilize this embodiment, during the process of aligning the locking groove 5 with the locking hook 3, the locking hook 3 contacts the mating groove 8 and slides on the groove surface of the mating groove 8; wherein, the locking hook 3 is located at the bottom of the center of gravity of the fuselage of the fixed-wing UAV; the mating groove 8 is a concave elliptical structure, which is set on the upper side of the fuselage of the multi-rotor UAV, and the mating groove 8 is provided with the locking groove 5.

[0089] Since the entire recovery process is achieved by a multi-rotor drone carrying a fixed-wing drone, the locking mechanism is as follows: the locking hook 3 is located on the lower side of the fixed-wing drone, and the locking groove 5 is located on the upper side of the multi-rotor drone. This allows the multi-rotor drone to slide the locking hook 3 on the groove surface of the mating groove 8 through its upward movement, so that the locking hook 3 eventually falls into the locking groove 5, thereby locking the multi-rotor drone onto the fixed-wing drone.

[0090] Based on this, the locking hook 3 is located at the bottom of the fixed-wing UAV's center of gravity, minimizing its impact on the fixed-wing UAV's flight attitude during the multi-rotor UAV's ascent and locking process, thus achieving better locking. The mating groove 8 provides error control for the locking process. It is understood that during the recovery process, both the fixed-wing and multi-rotor UAVs are in constant motion. Therefore, weather conditions and other objective factors may cause changes in the flight attitude of the multi-rotor and / or fixed-wing UAVs during locking. If the flight attitude changes, the locking hook 3 may not be able to align with the locking groove 5 during locking, thus failing to achieve locking. Therefore, with the mating groove 8 in place, if there is a positional error, the locking hook 3 will slide on the mating groove 8, eventually falling into the locking groove 5 during the sliding process.

[0091] Therefore, the UAV recovery method of this embodiment can dock a fixed-wing UAV and a multi-rotor UAV in the air to form a new composite UAV, thereby achieving vertical landing in relatively limited terrain. At this time, the fixed-wing UAV recovered by this method can reduce damage to the UAV and avoid setting up a large recovery device. Compared with parachute recovery, it further reduces the uncertainty of landing. In addition, compared with conventional composite-wing UAVs, it enables the fixed-wing UAV performing the mission to have the same or better flight performance indicators, while reducing the weight of the UAV, optimizing aerodynamics, increasing flight time, and expanding the flight envelope.

[0092] Understandably, the aforementioned drone recovery methods are typically applied to one-to-one fixed-wing and multi-rotor drones. Of course, without considering the size of multi-rotor drones, a multi-rotor drone can recover multiple fixed-wing drones at once. However, for safety reasons, fixed-wing and multi-rotor drones are generally set up in a one-to-one configuration.

[0093] As can be seen from the above, the method for recovering the UAV is achieved through the cooperation of fixed-wing UAVs, multi-rotor UAVs, and ground station systems.

[0094] like Figure 3 As shown, based on this, a ground station system is disclosed in this embodiment, including a control device.

[0095] The control device is a first control device, which includes a first memory and a first processor; the first memory is used to store program instructions; the first processor is used to call the program stored in the memory to perform the following steps:

[0096] S201. Obtain the position information of the fixed-wing UAV, maintain the flight status of the fixed-wing UAV, and issue a take-off command to the multi-rotor UAV.

[0097] S202. Enable multi-rotor drones to track the navigation points of fixed-wing drones, thereby shortening the relative distance between the multi-rotor drones and fixed-wing drones;

[0098] S203. Adjust the flight parameters of the multi-rotor UAV to maintain the distance difference between the multi-rotor UAV and the fixed-wing UAV in the altitude direction;

[0099] S204. Adjust the relative movement distance between the multi-rotor UAV and the fixed-wing UAV for docking and recovery;

[0100] S205. Turn off the power system of the fixed-wing UAV and control the multi-rotor UAV to land at the preset location.

[0101] To better implement the drone recovery method, the first processor calls the program instructions stored in the first memory to execute the following steps:

[0102] S2031. When the fixed-wing UAV enters the visual capture range of the multi-rotor UAV, switch the coordinate navigation control to visual laser navigation control so that the docking visual marker 2 of the fixed-wing UAV is in the position of docking with the multi-rotor UAV.

[0103] In this embodiment, after the fixed-wing UAV completes its flight mission, the ground station system obtains the position information fed back by the fixed-wing UAV, calculates the position information, and enables the multi-rotor UAV to take off and head towards the location of the fixed-wing UAV. During the approach to the fixed-wing UAV, the navigation control type is switched in a timely manner, that is, the navigation point tracking is switched to visual laser navigation control, thereby realizing the docking between the multi-rotor UAV and the fixed-wing UAV. Finally, the power system of the fixed-wing UAV is turned off, and the UAV is recovered by the power system of the multi-rotor UAV.

[0104] like Figure 4 , Figure 6 , Figure 7 As shown in the figure, this embodiment also discloses a fixed-wing unmanned aerial vehicle, which includes a control device.

[0105] The control device is a second control device, which includes a second memory and a second processor; the second memory is used to store program instructions; the second processor is used to call the program stored in the memory to execute the following steps:

[0106] S301, Respond to control commands and maintain flight status;

[0107] S302. After completing the aerial docking, shut down the power system.

[0108] In this embodiment, after the fixed-wing UAV completes its flight mission, the ground station system issues control commands to the fixed-wing UAV. At this time, the fixed-wing UAV responds to the commands, specifically by maintaining its flight status. After completing the aerial docking, the fixed-wing UAV shuts down its power system through the ground station system, thereby enabling the multi-rotor UAV to carry the UAV and finally land and be recovered to the preset location.

[0109] In addition, the fixed-wing UAV also includes a fuselage and a power system installed on the fuselage; the power system is used to drive the fixed-wing UAV to fly; the bottom of the fuselage under the center of gravity is provided with a docking visual identification surface 2, and the docking visual identification surface 2 is provided with a spherical locking hook 3.

[0110] The aforementioned fuselage is the first fuselage 1. When the ground station system switches navigation commands, the corresponding functional components act on the docking visual marker surface 2, thereby effectively determining the distance between the multi-rotor UAV and the fixed-wing UAV. This distance can be understood as a good indication of whether the fixed-wing UAV is docking with the multi-rotor UAV. Furthermore, because the locking hook 3 has a spherical structure, locking the locking groove 5 is easier to achieve.

[0111] To better utilize this embodiment, the docking visual identification surface 2 is a protruding elliptical structure; the locking hook 3 is located in the middle of the docking visual identification surface 2.

[0112] Since the docking visual identification surface 2 has an elliptical structure, it can be well connected to the mating slot 8 set on the multi-rotor UAV, thus avoiding relative rotation between the two UAVs after docking and providing docking stability.

[0113] like Figure 5 , Figures 6-9 As shown in the figure, this embodiment also discloses a multi-rotor unmanned aerial vehicle, which includes a control device.

[0114] The control device is a third control device, which includes a third memory and a third processor; the third memory is used to store program instructions; the third processor is used to call the program stored in the memory to execute the following steps:

[0115] S401, Obtain control commands from the ground station system;

[0116] S402: Respond to control commands, take off, and approach the fixed-wing UAV that needs to be recovered;

[0117] S403, complete the aerial docking and land at the designated location.

[0118] It is understandable that there can be multiple fixed-wing UAVs in flight. When recovering fixed-wing UAVs, it is generally a one-to-one recovery. Therefore, the control commands of the ground station system to the fixed-wing UAVs are targeted control commands. That is, under normal circumstances, it controls one fixed-wing UAV for recovery, that is, the multi-rotor UAV flies close to the fixed-wing UAV.

[0119] To better implement the drone recovery method, the third processor calls program instructions stored in the third memory to execute the following steps:

[0120] S4021. When the fixed-wing UAV enters the visual capture range of the multi-rotor UAV, respond to the control command, activate the visual laser navigation control, and position the docking visual marker 2 of the fixed-wing UAV at the docking position of the multi-rotor UAV.

[0121] Based on this, the multi-rotor UAV also includes a fuselage and a power system installed on the fuselage, which is used to drive the multi-rotor UAV to fly; a locking slot 5 is provided on the top of the fuselage, and a ranging sensor 6 is provided in the locking slot 5; a visual sensor 7 is provided on one side of the locking slot 5.

[0122] Understandably, the aforementioned power system drives the propeller 15 of the multi-rotor UAV to rotate, thereby enabling the multi-rotor UAV to fly. The aforementioned fuselage is the second fuselage 4. When the ground station system issues control commands to the multi-rotor UAV, it simultaneously acquires the position information of the fixed-wing UAV, thereby taking off and flying towards the fixed-wing UAV. Through the ranging sensor 6, the multi-rotor UAV can calculate its relative position with the fixed-wing UAV. When the fixed-wing UAV enters the visual capture range of the multi-rotor UAV, the visual sensor 7 is activated. The visual sensor 7 uses image algorithms to analyze the orientation of the docking visual marker surface 2 of the fixed-wing UAV, thereby readjusting the flight attitude of the multi-rotor UAV to meet the basic conditions for docking.

[0123] In this embodiment, the functional component of the ranging sensor 6 is a single-point laser ranging laser emitter, and the visual sensor 7 is a line-of-sight camera, thus satisfying the retrieval conditions.

[0124] To better utilize this embodiment, the top of the body is provided with a mating groove 8, which is a concave elliptical structure, and the locking groove 5 is located in the middle of the mating groove 8.

[0125] The mating groove 8 is a concave elliptical structure, which is correspondingly set on the docking visual identification surface 2 of the fixed-wing UAV. When the two are mated, the locking hook 3 is simultaneously locked in the locking groove 5, thereby effectively preventing relative rotation between the two UAVs.

[0126] To better utilize this embodiment, the multi-rotor UAV also includes a rotor arm 9 and a buffer mechanism; one end of the rotor arm 9 is connected to the second fuselage 4; the buffer mechanism is movably connected to the second fuselage 4 and movably connected to the rotor arm 9; the buffer mechanism has an elastic arresting cable 10.

[0127] Specifically, in this embodiment, the second fuselage 4 is connected to two rotor arms 9. The two rotor arms 9 are symmetrical with respect to the central vertical plane of the second fuselage 4, and each rotor arm 9 has a corresponding buffer mechanism. In other embodiments, the rotor arms 9 penetrate the second fuselage 4, and the portions of both ends outside the second fuselage 4 are of equal length. In this case, each end of the rotor arm 9 has a corresponding buffer mechanism.

[0128] Regarding the technical solution of this embodiment, this embodiment can solve the problem of fluctuations in relative altitude and relative speed between the fixed-wing UAV and the second fuselage 4 during the recovery and docking process of the fixed-wing UAV, and effectively absorb the impact when the fixed-wing UAV and the buffer device are recovered and locked.

[0129] In this embodiment, the elastic arresting cable 10 is a cable with good toughness, which can effectively stabilize the flight attitude of the fixed-wing UAV, constrain its position, and increase docking accuracy. Correspondingly, each buffer mechanism has an elastic arresting cable 10, and the two elastic arresting cables 10 are symmetrical with respect to the central vertical plane of the second fuselage 4. In this embodiment, the distance between the two elastic arresting cables 10 is the width of the fixed-wing UAV fuselage plus the lateral left-right position fluctuation error of the fixed-wing UAV.

[0130] To better utilize this embodiment, the buffer mechanism includes a first connecting rod 11, a second connecting rod 12, and a sleeve 13; one end of the first connecting rod 11 is connected to the second fuselage 4; the middle part of the second connecting rod 12 is connected to the other end of the first connecting rod 11; the sleeve 13 is slidably connected to the rotor arm 9 and movably connected to the first connecting rod 11.

[0131] This embodiment employs a lever-based layout, which effectively reduces the requirements for position and speed control when a fixed-wing UAV docks with a buffer device, expands the range of docking errors during the docking process, and effectively absorbs the impact generated during docking.

[0132] Specifically, the second link 12 can rotate relative to the second fuselage 4. Supported by the first link 11, the rotation of the second link 12 causes the sleeve 13 to slide on the rotor arm 9, thereby adjusting the height of the second link 12 and achieving the recovery of the docking impact at a suitable angle. It should be noted that, to ensure successful docking at high speed, the length of the second link 12 is greater than the maximum relative motion position error that the positioning and navigation system of the fixed-wing UAV and the second fuselage 4 can guarantee. Furthermore, the elastic arresting cable 10 further reduces the relative motion error of the fixed-wing UAV through elastic deformation during the docking approach, thereby ensuring docking accuracy.

[0133] Understandably, when the fixed-wing UAV begins docking, it first contacts the elastic arresting cable 10. Due to its elastic deformation, the cable restrains the fixed-wing UAV from moving towards the second fuselage 4. At this time, the second link 12 rotates toward the rotor arm 9, thereby avoiding collision damage between the fixed-wing UAV and the second fuselage 4.

[0134] Furthermore, the buffer mechanism also includes a third link 14; one end of the third link 14 is hinged to the first link 11, and the other end is hinged to the sleeve 13. Therefore, when the second link 12 rotates toward the rotor arm 9, the end of the third link 14 connected to the sleeve 13 moves toward the second fuselage 4, thereby increasing the rotational elastic force on the second link 12 and thus avoiding collision damage.

[0135] To better utilize this embodiment, the second connecting rod 12 has a curved structure that opens away from the plane where the second fuselage 4 is located; the two ends of the elastic arresting cable 10 are respectively connected to the two ends of the second connecting rod 12.

[0136] Because the second link 12 is curved, it can be equipped with a simple structure to set up the elastic arresting cable 10, avoiding the second fuselage 4 bearing a greater weight.

[0137] In this embodiment, the rotor arm 9 is connected to the fuselage via a tilting shaft.

[0138] In this embodiment, the second fuselage 4 is connected to two rotor arms 9. Based on this, for any rotor arm 9 on either side of the multi-rotor drone, one end of the tilt axis is rotatably connected to the fuselage, and the other end is connected to the rotor arm 9. The tilt angle can be adjusted according to the flight speed of the multi-rotor drone, thereby ensuring balance and stability when the multi-rotor drone and the fixed-wing drone dock.

[0139] It should be noted that the tilt axis has a tilt motor for driving its movement. Therefore, in order to ensure the stable level flight speed of the rotary-wing UAV and to follow the minimum level flight speed of the fixed-wing UAV, this embodiment drives the rotating axis through the tilt motor to realize the angle adjustment of the rotor arm 9, thereby shortening the stroke pressure of the rotor motor to ensure the level flight speed and increasing the maximum level flight speed.

[0140] This embodiment also discloses a drone recovery system, including a fixed-wing drone, a multi-rotor drone, and a ground station system. The fixed-wing drone is used for recovery in the air after completing its flight mission. The multi-rotor drone is used to dock with the fixed-wing drone in the air to achieve recovery of the fixed-wing drone. The ground station system is used to obtain the position of the fixed-wing drone, issue control commands to the fixed-wing drone and the multi-rotor drone, control the fixed-wing drone to maintain its flight state, control the multi-rotor drone to take off and approach the fixed-wing drone, and control the multi-rotor drone to dock with the fixed-wing drone. The ground station system is also used to shut down the power system of the fixed-wing drone after the fixed-wing drone docks with the multi-rotor drone, and instruct the multi-rotor drone to carry the fixed-wing drone to a preset location.

[0141] Therefore, by using the ground station system as a control platform, corresponding control is performed on fixed-wing UAVs and multi-rotor UAVs at different stages, thereby stably realizing the recovery of fixed-wing UAVs carried by multi-rotor UAVs.

[0142] This system generally has two main operational phases. After the fixed-wing UAV completes its flight mission, it needs to land nearby. The ground station system controls the multi-rotor UAV to take off and executes the UAV formation control program. The ground station system controls the multi-rotor UAV to follow the navigation points calculated from the current coordinates sent by the fixed-wing UAV. Once the multi-rotor UAV tracks the first navigation point of the fixed-wing UAV, the fixed-wing UAV immediately sends the next navigation point. This continues until the spatial coordinates of the fixed-wing UAV and the multi-rotor UAV are less than a first preset distance, thus completing the first phase of docking control. In this embodiment, the first preset distance is 10 meters.

[0143] In the next phase, the multi-rotor UAV continues to follow the navigation points calculated by the fixed-wing UAV. As the spatial coordinate distance between the two UAVs decreases, the fixed-wing UAV enters the visual capture range of the multi-rotor UAV. The UAV formation control is then changed from tracking the navigation points issued by the ground station system to visual laser navigation control. Visual image algorithms analyze the position of the fixed-wing UAV at the visual marker surface 2, controlling and adjusting the flight speed and position of the multi-rotor UAV. Simultaneously, through feedback from a single-point laser, the relative distance between the two UAVs is calculated in real time, maintaining their flight altitude at a second preset distance. In this embodiment, the second preset distance is 5 meters.

[0144] It is understandable that the aforementioned navigation points are the coordinate points in coordinate navigation. Therefore, the two UAVs maintain stable motion in the ground inertial coordinate system. The multi-rotor UAV's visual laser navigation continuously adjusts and tracks to reduce the relative motion difference between the two UAVs. When the relative motion is stable and the relative motion range is within the acceptable range for docking by the system, the multi-rotor UAV is controlled to reduce the spatial coordinate difference and dock. Alternatively, it can be understood that when the relative distance between the fixed-wing UAV and the multi-rotor UAV can no longer change, the locking can be considered successful.

[0145] During the above process, the two UAVs are tightly connected by the locking hook 3 and the locking slot 5. The ground station system issues control commands to shut down the power system of the fixed-wing UAV and slowly decelerate the power system of the rotary-wing UAV, eventually landing at the preset location.

[0146] Furthermore, this embodiment also discloses a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the over-the-air recovery method as described above.

[0147] Of course, when the computer program is executed by the processor, it can also control the control device as described in the above embodiments. Further details will not be elaborated here.

[0148] It should be noted that the steps of the methods described in conjunction with the above-disclosed embodiments can be implemented directly using hardware, a software program executed by a processor, or a combination of both. The software program can be placed in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0149] The above are merely preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be considered as limitations on the present invention, and the scope of protection of the present invention should be determined by the scope defined in the claims. For those skilled in the art, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for recovering unmanned aerial vehicles (UAVs), characterized in that, The method for recovering a fixed-wing drone from a multi-rotor drone in mid-air includes the following steps: The ground station system acquires the position information of the fixed-wing UAV, maintains the flight status of the fixed-wing UAV, and issues takeoff commands to the multi-rotor UAV. Multi-rotor drones can track the navigation points of fixed-wing drones, thereby reducing the relative distance between the two drones. Adjust the flight parameters of the multi-rotor drone to maintain the distance difference between the multi-rotor drone and the fixed-wing drone in the altitude direction; Adjust the relative movement distance between the multi-rotor drone and the fixed-wing drone for docking and recovery; Turn off the power system of the fixed-wing drone and control the multi-rotor drone to land at the preset location; In the process of adjusting the relative movement distance between the multi-rotor drone and the fixed-wing drone, the locking groove of the multi-rotor drone is aligned and docked with the locking hook of the fixed-wing drone. When the fixed-wing drone begins to dock, it first contacts the elastic arresting cable of the multi-rotor drone, restraining the fixed-wing drone to move closer to the multi-rotor drone. In the process of aligning the locking groove with the locking hook, the locking hook contacts the mating groove of the multi-rotor drone and slides on the groove surface. The locking hook is located at the bottom of the center of gravity of the fuselage of the fixed-wing UAV; the mating groove is a concave elliptical structure, which is set on the upper side of the fuselage of the multi-rotor UAV, and a locking groove is provided in the mating groove.

2. The method for recovering a drone as described in claim 1, characterized in that, The ground station system controls the multi-rotor UAV to approach the fixed-wing UAV via formation commands.

3. The method for recovering a drone as described in claim 2, characterized in that, It also includes the following steps: When the fixed-wing UAV enters the visual capture range of the multi-rotor UAV, the ground station system switches the coordinate navigation control provided by the formation command to visual laser navigation control, so that the docking visual marker surface of the fixed-wing UAV is in the position of the docking multi-rotor UAV.

4. A control device, characterized in that, A ground station system for the UAV recovery method as described in any one of claims 1 to 3, comprising: A first memory, used to store program instructions; and A first processor is used to call a program stored in a first memory to perform the following steps: Acquire the position information of the fixed-wing UAV, maintain the flight status of the fixed-wing UAV, and issue take-off commands to the multi-rotor UAV; This enables multi-rotor drones to track the navigation points of fixed-wing drones, thereby reducing the relative distance between the two types of drones. Adjust the flight parameters of the multi-rotor drone to maintain the distance difference between the multi-rotor drone and the fixed-wing drone in the altitude direction; Adjust the relative movement distance between the multi-rotor drone and the fixed-wing drone for docking and recovery; Turn off the power system of the fixed-wing drone and control the multi-rotor drone to land at the preset location.

5. A control device, characterized in that, A fixed-wing drone used in the drone recovery method as described in any one of claims 1 to 3, comprising: A second memory is used to store program instructions; and The second processor is used to call the program stored in the second memory to perform the following steps: Receive control commands from the ground station system; Respond to control commands and maintain flight status; After completing the aerial docking, shut down the power system.

6. A control device, characterized in that, A multi-rotor drone used in the drone recovery method as described in any one of claims 1 to 3, comprising: The third memory is used to store program instructions; and The third processor is used to call the program stored in the third memory to perform the following steps: Receive control commands from the ground station system; In response to control commands, it takes off and approaches the fixed-wing drone that needs to be recovered; After completing the aerial docking, land at the designated location.

7. A ground station system, characterized in that, Includes a control device as described in claim 4.

8. A fixed-wing unmanned aerial vehicle, characterized in that, include: First fuselage; The power system, located in the first fuselage, is used to drive the fixed-wing UAV in flight; as well as A control device as described in claim 5; The first fuselage has a docking visual identification surface at the bottom of the fuselage's center of gravity, and the docking visual identification surface has a spherical locking hook.

9. A fixed-wing unmanned aerial vehicle as described in claim 8, characterized in that, The docking visual identification surface is a protruding elliptical structure; the locking hook is located in the middle of the docking visual identification surface.

10. A multi-rotor unmanned aerial vehicle, characterized in that, include: Second fuselage; The power system, located in the second fuselage, is used to drive the multi-rotor drone in flight; as well as A control device as described in claim 6; The locking slot is equipped with a distance measuring sensor; a vision sensor is provided on one side of the locking slot.

11. A multi-rotor unmanned aerial vehicle as described in claim 10, characterized in that, Also includes: A rotor arm, one end of which is connected to the second fuselage; as well as A buffer mechanism, which is movably connected to the second fuselage and to the rotor arm; The buffer mechanism includes a first connecting rod, a second connecting rod, and a sleeve; one end of the first connecting rod is connected to the second fuselage; the middle part of the second connecting rod is connected to the other end of the first connecting rod; the sleeve is slidably connected to the rotor arm and movably connected to the first connecting rod. The buffer mechanism further includes a third link; one end of the third link is hinged to the first link, and the other end is hinged to the sleeve; The second link is a curved structure that opens outwards toward a plane away from the second fuselage; the two ends of the elastic arresting cable are respectively connected to the two ends of the second link.

12. A multi-rotor unmanned aerial vehicle as described in claim 11, characterized in that, The rotor arm is connected to the second fuselage via a tilting shaft.

13. A drone recovery system, characterized in that, The drone recovery method according to any one of claims 1 to 3 includes: Fixed-wing drones are used for aerial recovery after completing their flight missions. Multi-rotor drones are used to dock with fixed-wing drones in mid-air, enabling the recovery of the fixed-wing drones; and The ground station system is used to acquire the position of fixed-wing UAVs, issue control commands to fixed-wing UAVs and multi-rotor UAVs; control fixed-wing UAVs to maintain flight status; control multi-rotor UAVs to take off and approach fixed-wing UAVs; and control multi-rotor UAVs to dock with fixed-wing UAVs. The ground station system is also used to shut down the power system of the fixed-wing UAV after it docks with the multi-rotor UAV, and to instruct the multi-rotor UAV to carry the fixed-wing UAV to a preset location.

14. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the drone recovery method as described in any one of claims 1 to 3.

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