Water take-off and landing tail-sitter vertical take-off and landing unmanned aerial vehicle and flight control method thereof

Abstract

The application provides a water take-off and landing tail sitting type vertical take-off and landing unmanned aerial vehicle and a flight control method thereof, and the unmanned aerial vehicle is composed of a main body, a variable body landing gear and a foldable inflatable float. The variable body landing gear is symmetrically arranged on the upper and lower sides of the main body and is composed of a support rod and a tail support rod connected through a self-locking mechanism. The tail support rod is provided with a horizontal tail wing at the tail portion. The horizontal tail wing is a fan-shaped openable hollow structure, and the foldable inflatable float is arranged in the horizontal tail wing. The inflatable float is connected with an air pump arranged in the main body and can be inflated and deflated through the air pump. When inflated, the horizontal tail wing is opened to the two sides under the action of air pressure, the inflatable float is exposed to contact with the water surface to provide buoyancy, and after deflation, the horizontal tail wing is closed to provide a control moment as a control surface. The application can effectively meet the operation requirements of the unmanned aerial vehicle in three modes of vertical take-off and landing, cruising and water take-off and landing through the integrated design of the variable body landing gear and the foldable inflatable float, and the application range of the unmanned aerial vehicle is increased.

Description

Technical Field

[0001] This invention relates to the field of aviation technology, specifically to a tail-mounted vertical take-off and landing unmanned aerial vehicle (UAV) capable of taking off and landing on water and its flight control method. Background Technology

[0002] A seaplane, also known as a pontoon plane, is a modern technological aircraft that uses water surfaces, including oceans, lakes, and rivers, to take off, land, and park. Seaplanes are mostly divided into two types: hull-mounted and float-mounted.

[0003] In the prior art, patent document CN211893638U discloses a distributed-powered vertical take-off and landing (VTOL) aircraft, including a fuselage, canards, wings, horizontal stabilizer, vertical stabilizer, struts, several rotor power units, several distributed power units, support frame, floats, ailerons, elevators, and rudders. The fuselage is a conventional type, capable of carrying both passengers and cargo. The fuselage integrates flight control systems, electromechanical systems, and avionics systems. Although this utility model rationally arranges several rotor power units and several distributed power units, attempting to combine the advantages of fixed-wing aircraft and helicopters, its VTOL and cruise modes use two independent power units, resulting in heavy loads and low efficiency. In addition, the fixed float landing gear, while enabling take-off and landing on both ground and water, inevitably reduces its aerodynamic efficiency under various usage conditions and lacks the ability to take off and land in complex terrains with adaptive landing gear.

[0004] In the prior art, patent document CN102490895B discloses a folding inflatable float and a seaplane using the folding inflatable float. The folding inflatable float includes: a hydraulic drive device located in the middle of the folding inflatable float, used to extend or retract laterally along the folding inflatable float under the drive of a hydraulic controller; a folding support mechanism located inside the folding inflatable float, with its two ends connected to the two ends of the hydraulic drive device, used to realize the folding and unfolding of the folding inflatable float; a skin covering the periphery of the folding support mechanism, its interior forming a sealed space isolated from the outside, used for float shaping when the folding support mechanism is unfolded; and an inflation / deflation device located outside the skin, used for inflating and deflation of the sealed space formed by the skin. Although this invention's folding inflatable float can be opened or retracted, reducing air resistance during seaplane flight and increasing flight speed, it requires two actuators for the door and float retraction, in addition to the inflation device, increasing the dead weight of the airframe and the complexity of the mechanism. Summary of the Invention

[0005] In order to solve the problems of the prior art, the present invention provides a tail-mounted vertical take-off and landing unmanned aerial vehicle (UAV) capable of taking off and landing on water and its flight control method. The vertical take-off and landing UAV combines the advantages of fixed-wing and rotary-wing aircraft and has high reliability and high stability when taking off and landing on land and water.

[0006] This invention provides a tail-mounted vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) capable of taking off and landing on water, comprising a fuselage with wings distributed on both sides, and a power system and ailerons mounted on the wings. A set of symmetrically distributed variable landing gears is provided on the upper and lower sides of the fuselage. The variable landing gear includes a support rod control system, a tail strut control system, support rods, and tail struts. The support rods are symmetrically mounted on the left and right wings in two groups. The top of the support rod is hinged to the fuselage via the support rod control system, and the tail end of the support rod is hinged to the top of the tail strut via the tail strut control system. A tail strut vertical tail fin is mounted at the end of the tail strut, and the two tail strut vertical tail fins are connected by a tail strut horizontal tail fin. The tail strut control system is equipped with a self-locking mechanism to lock the attitude of the support rod and the tail strut. An inflatable float is fixed to the tail strut horizontal tail fin, and a jet nozzle is provided inside the tail strut horizontal tail fin.

[0007] The power system provides lift and attitude control capabilities for the vertical takeoff and landing UAV, and the motion envelope of the power system does not overlap with the motion envelope of the landing gear variant.

[0008] In a further improvement, the tail boom horizontal tail fin includes an upper section and a lower section. The upper and lower sections of the tail boom horizontal tail fin are hollow structures, hinged at the top, and magnetic plates are installed at the other docking positions. Inflatable floats are fixed inside the hollow positions of the upper and lower sections of the tail boom horizontal tail fin.

[0009] In a further improvement, an air pump is fixed inside the fuselage nacelle, with the bottom of the air pump connected to the outside air of the fuselage. The air pump is connected to the jet nozzle and the inflatable float via an air supply pipe.

[0010] Further improvements include a gear baffle on the outer support rod, with its upper end hinged to the support rod control system and its lower end forming a gear structure; a gear connecting plate at the top of the tail support rod, with its top end hinged to the concentric circle of the gear on the gear baffle; and a self-locking mechanism enclosed by a streamlined outer shell, comprising a large reduction gear, an upper rack section, a mating gear, a self-locking gear, a self-locking servo, a self-locking rocker arm, a synchronous servo, a synchronous gear, a connecting gear, a drive servo, a drive gear, and a lower rack section, wherein the large reduction gear and the self-locking gear are coaxial, and the large reduction gear shaft... The self-locking gear is positioned outwards and axially inwards to engage with the gear baffle. The synchronous servo is coaxial with the synchronous gear, the drive servo is coaxial with the drive gear, and the connecting gear is located between the synchronous gear and the drive gear, engaging with each other. The reduction gear, the upper section of the rack, the synchronous gear, the connecting gear, the drive gear, and the lower section of the rack form a gear and rack mechanism that drives each other. The output end of the self-locking servo is connected to the self-locking rocker arm, the bottom end of the self-locking rocker arm engages with the inner slide of the self-locking gear, and the top end of the self-locking gear is hinged to the gear connecting plate. The engagement and disengagement of the self-locking gear and the reduction gear are achieved through angular rotation.

[0011] The support rod is an H-shaped component consisting of a first outer baffle, a second outer baffle, a clamping plate, a connecting plate, and a gear baffle. The gear baffle is an outer baffle on one side of the H-shaped component. The outer baffle, the outer baffle, and the clamping plate are connected to form an outer baffle on the other side. The connecting plate is a middle horizontal plate.

[0012] The tail support includes a gear connecting plate, a servo middle baffle, a servo outer baffle, a servo connecting plate, a servo connecting plate lower baffle, and a servo inner baffle. The gear connecting plate is axially adjacent to the reduction gear, the upper section of the rack, the synchronizing gear, the connecting gear, the driving gear, and the lower section of the rack on its outer side. The servo middle baffle, the servo outer baffle, the servo connecting plate, the servo connecting plate lower baffle, and the servo inner baffle form four H-shaped components, which fix the self-locking servo, the synchronizing servo, and the driving servo within them. The servo connecting plate and the servo connecting plate lower baffle serve as the horizontal plates of the H-shaped components.

[0013] The present invention also provides a flight control method for a tail-mounted vertical take-off and landing unmanned aerial vehicle (UAV) capable of taking off and landing on water, comprising the following control processes:

[0014] Before vertical takeoff and after landing, the self-locking mechanism locks the support rod and tail support rod. The vertical takeoff and landing UAV is supported on the surface of the takeoff or parking area by the support rod, tail support rod, tail support horizontal tail fin and tail support vertical tail fin, which bear the main weight of the vertical takeoff and landing UAV and maintain attitude balance.

[0015] When a vertical takeoff and landing (VTOL) UAV performs an adaptive vertical landing, the self-locking mechanism is released, and the support rod control system and tail support rod control system drive the support rod and tail support rod to rotate. After adjusting the support rod and tail support rod to a posture that is highly compatible with the landing area environment, the self-locking mechanism locks the support rod and tail support rod, and the landing is carried out.

[0016] When a vertical take-off and landing (VTOL) drone performs an adaptive vertical landing on water, the inflatable floats inflate and contact the water surface to provide buoyancy to overcome the drone's gravity, while the jet nozzles provide reverse thrust to mitigate the instability caused by the floating of the sea surface. The self-locking mechanism is released, and the drone maintains its attitude balance through attitude adjustments via the support rods and tail struts.

[0017] During the transition from hovering to level flight or vice versa for a vertical takeoff and landing (VTOL) drone, the self-locking mechanism is released, and the support rod control system and tail boom control system drive the support rod and tail boom to rotate, causing the support rod and tail boom to adjust their attitude relative to the fuselage, assisting the VTOL drone in trimming. The tail boom horizontal stabilizer works in conjunction with the ailerons to adjust to the airflow direction, generating aerodynamic forces that help the fuselage fly. After the VTOL drone stabilizes, the landing gear gradually closes, the self-locking mechanism locks in, and the entire landing gear structure is located at the rear end of the fuselage.

[0018] The beneficial effects of this invention are as follows:

[0019] 1. The addition of a self-locking mechanism distributes the landing impact force among three servo motors, improving the reliability of the landing gear during land takeoffs and landings.

[0020] 2. During takeoff and landing on the water, the jet mechanism, in conjunction with the adaptive landing gear, improves the stability of the seaplane.

[0021] 3. Vertical takeoff and landing (VTOL) drones combine the advantages of fixed-wing and rotary-wing aircraft, significantly reducing the requirements for takeoff and landing conditions while possessing strong flight combat capabilities. They have broad application prospects in increasingly complex and precise scenarios in the future.

[0022] 2. Tail-mounted UAVs fix the thrust direction on the longitudinal axis of the fuselage and take off vertically by sitting on the tail. After reaching a certain altitude, they switch to level flight. When the thrust is reversed, the thrust and the fuselage rotate synchronously, which reduces the weight of the airframe and the takeoff and landing space. The aerodynamic coupling is also relatively simple.

[0023] 3. The innovative variant foldable landing gear not only adapts to both vertical takeoff and landing (VTOL) and cruise modes for tail-mounted UAVs, but also allows for selection of land / water takeoff and landing options based on mission and environmental requirements. During VTOL takeoff and landing in a land environment, the support rod and tail boom provide support and protection for the aircraft parked on the ground. Once the aircraft transitions to cruise mode, the symmetrically deployed tail booms on both sides can be actively controlled to engage with the support rods. This engagement reduces the additional drag from the tail boom and support rod structure itself. Because the main body is located at the rear of the fuselage, the horizontal and vertical stabilizers on the tail booms are far from the aircraft's center of gravity, resulting in longer lever arms for trim and control, stronger controllability, and lower additional drag during trim. This improves the aircraft's controllability and flight efficiency during mode transitions and VTOL landings. The symmetrical two-stage controllable landing gear can perform adaptive assisted trim adjustments and landing, enhancing its adaptability to missions in complex future environments. During vertical takeoff and landing in a water environment, the air pump transmits air to the inflatable float through the air supply pipe. The increased pressure inside the inflatable float pushes the upper and lower sections of the tail boom horizontal tail fin to separate and expose the inflatable float. The inflatable float provides buoyancy by contacting the water surface to overcome the weight of the vertical takeoff and landing UAV. The attitude balance of the vertical takeoff and landing UAV is maintained by attitude adjustment through the support rod and tail boom rod. There is no need for a folding drive mechanism, the structure is simple and lightweight, and the reliability is high. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A side view of a water-capable, tail-mounted, vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) in its VTOL state.

[0026] Figure 2 A side view of the mode-switching state of a tail-mounted vertical take-off and landing unmanned aerial vehicle (UAV) capable of taking off and landing on water.

[0027] Figure 3 A side view of a water-capable, tail-mounted, vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) in cruise mode.

[0028] Figure 4 A side view of a tail-mounted vertical take-off and landing unmanned aerial vehicle (UAV) in a water-based parking state.

[0029] Figure 5 This is a schematic diagram of a tail-mounted vertical take-off and landing UAV with adaptive wave height on the right side during a water landing.

[0030] Figure 6 This is a schematic diagram of an adaptive landing state where the left side of a tail-standing vertical take-off and landing (VTOL) drone, capable of taking off and landing on water, touches the ground first.

[0031] Figure 7 This is a schematic diagram of the adaptive attitude adjustment state of a tail-mounted vertical take-off and landing unmanned aerial vehicle (UAV) capable of taking off and landing on water.

[0032] Figure 8 This is a schematic diagram of a self-locking mechanism;

[0033] Among them, 1-power system, 2-fuselage, 3-wing, 4-support rod control system, 5-aileron, 6-tail strut control system, 61-large gear, 62-upper rack section, 63-meshing gear, 64-self-locking gear, 65-self-locking servo, 66-self-locking rocker arm, 67-synchronous servo, 68-synchronous gear, 69-connecting gear, 610-drive servo, 611-drive gear, 612-lower rack section, 7-support rod, 71-first outer baffle of support rod 72 - Support rod second outer baffle; 73 - Support rod clamp; 74 - Connecting plate; 75 - Gear baffle; 8 - Tail support rod; 81 - Gear connecting plate; 82 - Servo middle baffle; 83 - Servo outer baffle; 84 - Servo connecting plate; 85 - Servo connecting plate lower; 86 - Servo inner baffle; 9 - Tail support horizontal tail fin; 91 - Tail support horizontal tail fin upper section; 92 - Tail support horizontal tail fin lower section; 10 - Tail support vertical tail fin; 11 - Inflatable float; 12 - Air pump; 13 - Air supply pipe. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] This invention provides a tail-mounted vertical take-off and landing unmanned aerial vehicle (UAV) capable of taking off and landing on water, with the structure as follows: Figure 1-7 As shown, the fuselage 2 includes wings 3 distributed on both sides. A power system 1 is mounted on each wing 3. A set of symmetrically distributed variable landing gear is arranged on the upper and lower sides of the fuselage 2. The variable landing gear includes a support rod control system 4, a tail boom control system 6, support rods 7, tail booms 8, and a tail boom horizontal stabilizer 9. The support rods 7 are symmetrically mounted on the left and right wings 3 in two groups. The top of the support rod 7 is hinged to the fuselage 2 via the support rod control system 4, and the tail end of the support rod 7 is hinged to the top of the tail boom 8 via the tail boom control system 6. A tail boom vertical stabilizer 10 is mounted at the end of the tail boom 8. The two tail boom vertical stabilizers 10 are connected by the tail boom horizontal stabilizer 9. An inflatable float 11 is fixed to the tail boom horizontal stabilizer 9, and a jet nozzle is provided inside the tail boom horizontal stabilizer 9. The tail boom control system 6 is equipped with a self-locking mechanism to lock the attitude of the support rods 7 and 8.

[0036] The power system 1 provides lift for the vertical take-off and landing UAV and has attitude control capabilities. The motion envelope of the power system 1 does not overlap with the motion envelope of the landing gear variant.

[0037] The tail boom horizontal tail fin 9 includes an upper section 91 and a lower section 92. The upper section 91 and the lower section 92 are hollow structures, hinged at the top, and magnetic plates are installed at the other docking positions. The inflatable float 11 is fixed in the hollow position inside the upper section 91 and the lower section 92 of the tail boom horizontal tail fin.

[0038] An air pump 12 is fixed inside the nacelle of the fuselage 2. The bottom of the air pump 12 is connected to the outside air of the fuselage 2. The air pump 12 is connected to the inflatable float 11 through the air supply pipe 13.

[0039] As shown in Figure 8, the support rod 7 includes a first outer baffle 71, a second outer baffle 72, a support rod clamping plate 73, a connecting plate 74, and a gear baffle 75. The upper end of the gear baffle 75 is hinged to the support rod control system 4, and the lower end is a gear structure. The first outer baffle 71, the second outer baffle 72, the support rod clamping plate 73, the connecting plate 74, and the gear baffle 75 form an H-shaped component as the lower end of the support rod 7. The gear baffle 75 is the outer baffle on one side of the H-shaped component. The first outer baffle 71, the second outer baffle 72, and the support rod clamping plate 73 are connected to form the outer baffle on the other side. The connecting plate 74 is a middle horizontal plate.

[0040] The self-locking mechanism includes a large reduction gear 61, an upper rack section 62, a mating gear 63, a self-locking gear 64, a self-locking servo motor 65, a self-locking rocker arm 66, a synchronizing servo motor 67, a synchronizing gear 68, a connecting gear 69, a driving servo motor 610, a driving gear 611, and a lower rack section 612.

[0041] The reduction gear 61 and the self-locking gear 64 are coaxial. The reduction gear 61 is axially outward, and the self-locking gear 64 is axially inward, adjacent to the inner baffle 86 of the servo motor and cooperating with the gear baffle 75. The synchronous servo motor 67 and the synchronous gear 68 are coaxial. The drive servo motor 610 and the drive gear 611 are coaxial. The connecting gear 69 is located between the synchronous gear 68 and the drive gear 611 and cooperates with each other. The reduction gear 61, the upper rack section 62, the synchronous gear 68, the connecting gear 69, the drive gear 611 and the lower rack section 612 constitute a gear and rack mechanism that drives each other. The output end of the self-locking servo motor 65 is connected to the self-locking rocker arm 66. The bottom end of the self-locking rocker arm 66 cooperates with the inner slide of the self-locking gear 64. The top end of the self-locking gear 64 is hinged to the gear connecting plate 81. The meshing and disengagement of the self-locking gear 64 and the reduction gear 61 can be achieved by rotating the angle.

[0042] The tail support rod 8 also includes a gear connecting plate 81, a servo motor middle baffle 82, a servo motor outer baffle 83, a servo motor connecting plate 84, a servo motor connecting plate lower 85, and a servo motor inner baffle 86.

[0043] The top of the gear connecting plate 81 is hinged to the gear baffle 75 at the concentric circle of the gear. Its outer axial direction is adjacent to the reduction gear 61, the upper rack section 62, the synchronizing gear 68, the connecting gear 69, the driving gear 611, and the lower rack section 612. The servo motor middle baffle 82, the servo motor outer baffle 83, the servo motor connecting plate upper 84, the servo motor connecting plate lower 85, and the servo motor inner baffle 86 form four H-shaped components, which fix the self-locking servo motor 65, the synchronizing servo motor 67, and the driving servo motor 610 in them. The servo motor connecting plate upper 84 and the servo motor connecting plate lower 85 serve as the horizontal plates of the H-shaped components.

[0044] The present invention also provides a flight control method for a tail-mounted vertical take-off and landing unmanned aerial vehicle (UAV) capable of taking off and landing on water, comprising the following control processes:

[0045] Before and after vertical takeoff and landing of the VTOL UAV, the self-locking mechanism locks the support rod 7 and tail support rod 8. The VTOL UAV is supported on the surface of the takeoff or parking area by the support rod 7, tail support rod 8, tail support horizontal tail 9 and tail support vertical tail 10, which bear the main weight of the VTOL UAV and maintain attitude balance.

[0046] When the vertical take-off and landing UAV performs an adaptive vertical landing, the self-locking mechanism is released, and the support rod control system 4 and the tail support rod control system 6 drive the support rod 7 and the tail support rod 8 to rotate. After adjusting the support rod 7 and the tail support rod 8 to a posture that is highly compatible with the landing area environment, the self-locking mechanism locks the support rod 7 and the tail support rod 8, and the landing is carried out.

[0047] When the vertical take-off and landing UAV performs an adaptive vertical landing on water, the air pump 12 transmits air to the inflatable float 11 through the air supply pipe 13. The increased pressure inside the inflatable float 11 pushes the upper section 91 and the lower section 92 of the tail boom horizontal tail fin to separate and expose the inflatable float 11. The inflatable float 11 provides buoyancy by contacting the water surface to overcome the weight of the vertical take-off and landing UAV. The jet nozzle provides reverse thrust to reduce the instability caused by the floating of the sea surface. The self-locking mechanism is released, and the UAV maintains its attitude balance by adjusting the attitude of the support rod 7 and the tail boom rod 8.

[0048] During the mode transition from hovering to level flight or from level flight to hovering of the VTOL UAV, the self-locking mechanism is released, and the support rod control system 4 and the tail boom control system 6 drive the support rod 7 and tail boom 8 to rotate, so that the support rod 7 and tail boom 8 adjust their attitude relative to the fuselage 2, assisting the VTOL UAV in trimming. The tail boom horizontal stabilizer 9 and the aileron 5 work together to adjust to the airflow direction, generating aerodynamic forces that help the fuselage 2 fly. After the VTOL UAV stabilizes, the landing gear gradually closes, and the self-locking mechanism locks in. The entire landing gear structure is located at the tail end of the fuselage 2. The distance between the tail boom horizontal stabilizer 9 and the center of gravity of the VTOL UAV is the sum of the lengths of the support rod 7 and tail boom 8. The length parameters of the support rod 7 and tail boom 8 must ensure that the tail boom horizontal stabilizer 9 has good handling performance.

[0049] The locking and unlocking process of the self-locking mechanism is as follows:

[0050] When the support rod 7 and the tail support rod 8 are directly fixed in attitude, the self-locking servo 65 controls the self-locking rocker arm 66 to rotate, so that the self-locking gear 64 approaches the gear connecting plate 81 and is hinged to it. At this time, the impact force of the tail support rod 8 landing is transmitted to the mating gear 63 by the gear baffle 75, and then distributed to the self-locking servo 65, the synchronous servo 67, and the drive servo 610 by the coaxial reduction gear 61 through meshing and gear rack transmission.

[0051] When the angle between the support rod 7 and the tail support rod 8 is adjusted, the self-locking servo motor 65 controls the self-locking rocker arm 66 to rotate in the opposite direction, so that the self-locking gear 64 moves away from the gear connecting plate 81 and separates from it. The synchronous servo motor 67 and the drive servo motor 610 drive the gear rack to drive the mating gear 63 and the gear baffle 75 to rotate 2.

[0052] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiments, the above descriptions are merely preferred embodiments of the present invention. Since they are fundamentally similar to the method embodiments, the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention, without departing from the principle of the present invention, should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A tail-mounted vertical take-off and landing unmanned aerial vehicle (UAV) capable of taking off and landing on water, comprising a fuselage (2) with wings (3) distributed on both sides, a power system (1) mounted on the wings (3), and a set of symmetrically distributed variant landing gears on the upper and lower sides of the fuselage (2), the variant landing gears comprising a support rod control system (4), a tail strut control system (6), a support rod (7), a tail strut (8), and a tail strut horizontal tail fin (9), wherein, The support rods (7) are symmetrically installed on the left and right wings (3) in two groups. The top of the support rods (7) is hinged to the fuselage (2) through the support rod control system (4). The tail end of the support rods (7) is hinged to the top of the tail support rods (8) through the tail support rod control system (6). The tail support rods (8) are equipped with tail support vertical tail fins (10). The two tail support vertical tail fins (10) are connected by tail support horizontal tail fins (9). The tail support rod control system (6) is equipped with a self-locking mechanism to lock the attitude of the support rods (7) and tail support rods (8). An inflatable float (11) is fixed on the tail support horizontal tail fin (9). A jet is provided inside the tail support horizontal tail fin (9). Nozzle; the tail support horizontal tail fin (9) includes an upper section (91) and a lower section (92) of the tail support horizontal tail fin. The upper section (91) and the lower section (92) of the tail support horizontal tail fin are hollow structures and are hinged at the top. Magnetic plates are installed at the other docking positions. The inflatable float (11) is fixed in the hollow position inside the upper section (91) and the lower section (92) of the tail support horizontal tail fin. The outer baffle of the support rod is a gear baffle (75). The upper end of the gear baffle (75) is hinged to the support rod control system (4), and the lower end is a gear structure. The top of the tail support rod (8) is a gear connecting plate (81). The top of the gear connecting plate (81) is connected to the gear baffle (75). 5) The gears are hinged at the concentric circle; the self-locking mechanism includes a large reduction gear (61), an upper rack section (62), a mating gear (63), a self-locking gear (64), a self-locking servo (65), a self-locking rocker arm (66), a synchronous servo (67), a synchronous gear (68), a connecting gear (69), a drive servo (610), a drive gear (611), and a lower rack section (612). The large reduction gear (61) and the self-locking gear (64) are coaxial. The large reduction gear (61) is axially outward, and the self-locking gear (64) is axially inward and meshes with the gear baffle (75). The synchronous servo (67) and the synchronous gear (68) are coaxial, and the drive servo (610) is also coaxial. The drive gear (611) is coaxial with the connecting gear (69), which is located between the synchronous gear (68) and the drive gear (611) and cooperates with each other. The reduction gear (61), the upper rack section (62), the synchronous gear (68), the connecting gear (69), the drive gear (611) and the lower rack section (612) constitute a gear and rack mechanism that drives each other. The output end of the self-locking servo motor (65) is connected to the self-locking rocker arm (66). The bottom end of the self-locking rocker arm (66) cooperates with the inner slide of the self-locking gear (64). The top end of the self-locking gear (64) is hinged to the gear connecting plate (81). The meshing and separation of the self-locking gear (64) and the reduction gear (61) are realized by angular rotation.The support rod is an H-shaped component consisting of a first outer baffle (71), a second outer baffle (72), a support rod clamping plate (73), a connecting plate (74), and a gear baffle (75). The gear baffle (75) is an outer baffle on one side of the H-shaped component. The first outer baffle (71), the second outer baffle (72), and the support rod clamping plate (73) are connected to form an outer baffle on the other side. The connecting plate (74) is a middle horizontal plate. The tail support rod (8) includes a gear connecting plate (81), a servo motor middle baffle (82), a servo motor outer baffle (83), a servo motor connecting plate upper (84), and a servo motor connecting plate lower (85). The inner baffle (86) of the servo motor and the gear connecting plate (81) are axially adjacent to the reduction gear (61), the upper rack section (62), the synchronous gear (68), the connecting gear (69), the drive gear (611), and the lower rack section (612). The middle baffle (82) of the servo motor, together with the outer baffle (83), the upper connecting plate (84), the lower connecting plate (85), and the inner baffle (86) of the servo motor, form four H-shaped components, which fix the self-locking servo motor (65), the synchronous servo motor (67), and the drive servo motor (610) within them. The upper connecting plate (84) and the lower connecting plate (85) of the servo motor serve as the horizontal plates of the H-shaped components.

2. The water-launchable, tail-mounted, vertical takeoff and landing UAV according to claim 1, characterized in that: An air pump (12) is fixed inside the nacelle of the fuselage (2). The bottom of the air pump (12) is connected to the outside air of the fuselage (2). The air pump (12) is connected to the jet nozzle and the inflatable float (11) through the air supply pipe (13).

3. A flight control method for a tail-mounted vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) capable of water takeoff and landing, employing the tail-mounted VTOL UAV as described in claim 1, characterized in that... The following control processes are included: Before and after vertical take-off and landing of the VTOL UAV, the self-locking mechanism locks the support rod (7) and tail support rod (8). The VTOL UAV is supported on the surface of the take-off or parking area by the support rod (7), tail support rod (8), tail support horizontal tail (9) and tail support vertical tail (10), which bear the main weight of the VTOL UAV and maintain attitude balance. When the vertical take-off and landing UAV performs an adaptive vertical landing on the ground, the self-locking mechanism is released, and the support rod control system (4) and the tail support rod control system (6) drive the support rod (7) and tail support rod (8) to rotate. After adjusting the support rod (7) and tail support rod (8) to a posture that is highly compatible with the landing area environment, the self-locking mechanism locks the support rod (7) and tail support rod (8) to perform the landing. When the vertical take-off and landing UAV performs adaptive vertical landing on water, the inflatable float (11) is inflated and contacts the water surface to provide buoyancy to overcome the weight of the vertical take-off and landing UAV, the jet nozzle provides reverse thrust, the self-locking mechanism is released, and the UAV maintains attitude balance through attitude adjustment of the support rod (7) and tail support rod (8). During the mode transition from hovering to level flight or from level flight to hovering of the VTOL UAV, the self-locking mechanism is released, and the support rod control system (4) and tail support rod control system (6) drive the support rod (7) and tail support rod (8) to rotate, so that the support rod (7) and tail support rod (8) adjust their attitude relative to the fuselage (2), assisting the VTOL UAV in trimming. The tail support horizontal tail (9) and aileron (5) work together to adjust and adapt to the airflow direction, generating aerodynamic force that helps the fuselage (2) fly. After the VTOL UAV stabilizes, the landing gear gradually closes, the self-locking mechanism locks, and the overall landing gear structure is located at the tail end of the fuselage (2).

4. The flight control method for a tail-mounted vertical takeoff and landing unmanned aerial vehicle (UAV) according to claim 3, characterized in that: During the adaptive vertical landing of the vertical take-off and landing UAV on water, the air pump (12) transmits air to the inflatable float (11) through the air pipe (13). The increased pressure inside the inflatable float (11) pushes the upper section (91) and lower section (92) of the tail boom horizontal tail fin to separate and expose the inflatable float (11).

5. The flight control method for a tail-mounted vertical takeoff and landing unmanned aerial vehicle (UAV) according to claim 3, characterized in that: During the mode transition from hovering to level flight or from level flight to hovering of the vertical take-off and landing UAV, after the UAV stabilizes, the distance between the tail boom horizontal tail fin (9) and the center of gravity of the UAV is the sum of the lengths of the support rod (7) and the tail boom rod (8).

6. The flight control method for a tail-mounted vertical takeoff and landing unmanned aerial vehicle (UAV) according to claim 3, characterized in that: The locking and unlocking process of the self-locking mechanism is as follows: When the support rod (7) and the tail support rod (8) are directly fixed in posture, the self-locking servo (65) controls the self-locking rocker arm (66) to rotate, so that the self-locking gear (64) approaches the gear connecting plate (81) and is hinged to it. At this time, the impact force of the tail support rod (8) landing is transmitted to the mating gear (63) by the gear baffle (75), and then distributed to the self-locking servo (65), the synchronous servo (67), and the drive servo (610) by the coaxial reduction gear (61) through meshing and gear rack transmission relationship. When the angle between the support rod (7) and the tail support rod (8) is adjusted, the self-locking servo (65) controls the self-locking rocker arm (66) to rotate in the opposite direction, so that the self-locking gear (64) moves away from the gear connecting plate (81) and separates from it. The synchronous servo (67) and the drive servo (610) drive the gear rack to drive the mating gear (63) to rotate in coordination with the gear baffle (75) (2).

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