A compound wing unmanned aerial vehicle with hovering folding and retracting function and a control method thereof

Abstract

The application discloses a compound wing unmanned aerial vehicle with hovering folding and shrinking functions and a control method thereof, and belongs to the technical field of unmanned aerial vehicle structures and intelligent control. The core of the application adopts a cooperative deformation architecture of wing upward folding + tail wing axial stretching and shrinking, realizes 90-degree vertical storage of the wing through an embedded worm gear self-locking folding mechanism, realizes accurate axial retraction of the tail wing through a small thread angle screw rod self-locking stretching and shrinking mechanism, and only triggers deformation in the steady state working condition of unmanned aerial vehicle positioning hovering, stably realizes 50% to 60% compression of the wing span and 30% to 40% reduction of the longitudinal length of the whole machine, greatly reduces the three-dimensional envelope size of the unmanned aerial vehicle, and can adapt to standard building windows and other narrow space passing operations. The application is matched with a control method to establish a safe interlocking logic of "steady state preposition, step-by-step linkage, closed loop self-checking and orderly reset", eliminates safety risks such as deformation false triggering, structural loosening and attitude out of control from the dual dimensions of hardware self-locking and software control, and solves the industry pain points of single deformation mode of traditional compound wing unmanned aerial vehicles, poor passing performance in narrow space and low operation safety. The application is compact in structure, controllable in self-weight and strong in adaptability, and can be widely applied to high-rise building fire rescue, post-disaster debris search and rescue, urban narrow area inspection, complex jungle environment operation and other scenes, and has wide engineering application value and industrialization prospect.

Description

Technical Field

[0001] This invention belongs to the field of UAV structural design and intelligent flight control technology, specifically relating to a large-scale adaptive deformation compound wing UAV capable of folding its wings upwards and synchronously retracting its tail fin axially under steady-state hovering conditions. It is particularly suitable for various confined space operations such as high-rise building fire rescue, post-disaster rubble inspection, passage through narrow urban alleys, and jungle gap operations. Background Technology

[0002] The compound-wing UAV integrates the core advantages of multi-rotor vertical take-off and landing, fixed-point hovering and fixed-wing high-speed cruise and long-endurance flight. It does not rely on runways for take-off and landing, and takes into account both operational flexibility and flight efficiency. It has irreplaceable application value in fields such as emergency rescue, public security, environmental monitoring and power line inspection, and is currently the mainstream model for complex airspace operations.

[0003] However, existing conventional compound-wing UAVs all adopt a fixed overall configuration, with fixed lateral wingspan, longitudinal fuselage, and tail dimensions, making it impossible to adaptively adjust the envelope size according to the operating environment. When facing confined spaces such as windows in high-rise buildings, narrow wall gaps, dense tree canopy gaps, and narrow streets, the fixed fuselage size becomes a barrier to passage. Taking the industry's mainstream 2.5m wingspan compound-wing UAV as an example, its maximum lateral width in its fully deployed state is no less than 2.5m, and the total longitudinal length from the nose to the trailing edge of the tail is no less than 1.8m. It cannot pass through conventional 1.2m standard building windows and narrow passages of the same size, greatly limiting the operational coverage range of UAVs in urban rescue and complex field scenarios.

[0004] While some folding-wing drone solutions have been disclosed in the existing technology, they all suffer from fundamental technical flaws and cannot meet the requirements of high-precision and safe operations in confined spaces: First, traditional folding wings mostly adopt downward or backward folding structures. When the drone operates at low altitudes near the ground or through gaps, the folding wings are extremely prone to hitting the ground or walls, causing structural damage. Furthermore, during flight, updrafts continuously impact the folding wing surface, leading to fuselage vibration and attitude instability, resulting in extremely poor folding reliability. Second, existing folding solutions only optimize the deformation of the wing in a single dimension, without adapting the longitudinal dimension of the tail to the shrinkage, thus compromising the overall drone performance. The longitudinal envelope size is not substantially reduced, and the improvement in three-dimensional passability in confined spaces is extremely limited; third, the existing technology lacks a coordinated deformation architecture for wing folding and tail retraction, and there is no dedicated hovering safety interlock logic. Deformation actions can be mistakenly triggered under non-steady conditions such as forward flight, climb, and side flight of the UAV, which can easily lead to major safety accidents such as fuselage structural distortion, loss of flight attitude control, and mid-air crashes; fourth, conventional deformation structures lack power-off self-locking and full-stroke limit self-checking mechanisms. Under flight vibration and airflow disturbances, structural displacement and deformation failure are prone to occur, and the operational safety and stability cannot meet the requirements of actual combat.

[0005] In summary, existing compound-wing UAVs generally suffer from technical shortcomings such as fixed configuration, poor three-dimensional maneuverability, limited deformation modes, lack of coordinated retraction capabilities, missing safety control logic, and insufficient structural stability. The industry urgently needs a compound-wing UAV and its supporting control method that can achieve large-scale coordinated deformation of the wings and tail in both directions only in a hovering steady state, possesses a self-locking stabilizing structure, and has closed-loop safety interlocking control. Summary of the Invention

[0006] This invention aims to solve the following core technical problems in the prior art: First, it addresses the issue that traditional compound-wing UAVs cannot achieve large-scale coordinated deformation of the wings and tail, resulting in a lack of significant reduction in the overall lateral and longitudinal envelope dimensions and poor maneuverability in confined three-dimensional spaces. Second, it addresses the problems of existing folding UAVs having no operational condition restrictions on deformation triggering, being prone to accidental deformation triggering during flight, lacking a safety interlocking mechanism, and posing high operational risks. Third, it addresses the problem that conventional deformation structures lack self-locking capabilities, are prone to displacement and loosening under flight conditions, and have poor structural stability. Fourth, it addresses the technical bottleneck that traditional single-wing folding cannot achieve small-envelope adaptation of the entire aircraft, failing to meet the passage requirements of regular and narrow passages such as standard windows.

[0007] To achieve the above-mentioned objectives and overcome the shortcomings of the prior art, this invention provides a compound-wing unmanned aerial vehicle (UAV) with hovering, folding, and retracting functions, and its control method. The specific technical solution is as follows: A compound-wing UAV with hovering, folding, and retracting functions includes a fuselage, wings symmetrically arranged on the left and right sides of the fuselage, a tail fin mounted at the rear of the fuselage, and an axial telescopic assembly connecting the fuselage and the tail fin. The wings are divided into a mid-section rigidly fixed to the fuselage and a self-adaptive folding section. An electric folding mechanism is installed between the mid-section and the folding section. The rear of the fuselage is rigidly connected to the tail fin through the telescopic assembly, which can drive the tail fin to precisely extend and retract along the longitudinal central axis of the fuselage, thereby achieving adaptive adjustment of the overall longitudinal dimensions of the UAV.

[0008] The wing folding mechanism includes a folding drive motor, a worm gear, a worm wheel, and a horizontal folding shaft. The folding shaft is horizontally arranged along the front-rear direction of the fuselage. The outer end of the wing midsection and the inner end of the wing folding section are hinged together by the folding shaft. The folding drive motor is completely embedded inside the wing midsection with no exposed structure, reducing wind resistance. The output shaft of the folding drive motor is rigidly fixed coaxially with the worm gear, and the worm wheel is locked coaxially with the folding shaft. The worm gear and worm wheel precisely mesh to form a reduction transmission pair. When the folding drive motor outputs power, it drives the wing folding section to rotate vertically upward around the folding shaft through the worm gear and worm wheel reduction transmission. The maximum folding angle can reach 90°, which completely transforms the wing folding section from a horizontal cruising flat state to a vertical folding state, achieving a precise large-scale compression of the UAV's wingspan of 50% to 60%.

[0009] The telescopic assembly includes a telescopic sleeve, a telescopic tube, a telescopic drive motor, a transmission screw, and a screw slider. The telescopic sleeve is rigidly embedded and fixed in the inner cavity of the tail section of the fuselage. The telescopic tube is coaxially slidably inserted inside the telescopic sleeve, with its rear end extending out of the sleeve and rigidly fixedly connected to the front end of the tail fin. The telescopic drive motor is rigidly fixed to the tail end inside the fuselage via an insulated and shock-absorbing motor mount. The output shaft of the telescopic drive motor is coaxially fixedly connected to the transmission screw, which extends axially along the telescopic tube to the center of the inner cavity of the telescopic tube. The screw slider is interference-fitted to the middle section of the inner wall of the telescopic tube and forms a high-precision threaded transmission fit with the transmission screw. The telescopic drive motor drives the transmission screw to rotate forward and backward, converting the rotational motion into axial linear motion of the telescopic tube through the screw slider. This, in turn, drives the tail fin to precisely retract or extend backward toward the fuselage, achieving a controllable reduction and repositioning of the overall longitudinal length of the UAV by 30% to 40%.

[0010] Furthermore, the worm gear and worm wheel adopt a large friction angle tooth design, forming a mechanical reverse self-locking transmission pair. Folding and unfolding can only be achieved by active driving of the folding motor. After power failure, the rotation of the folding shaft can be completely locked. Without external force intervention, the wing folding section can permanently lock the current folding angle, preventing loosening, rebound, and deviation caused by flight airflow and vibration. The transmission screw and screw slider adopt a small thread helix angle design, with the thread helix angle strictly less than the equivalent friction angle, forming a high-precision self-locking thread pair. After the telescopic motor is powered off, the axial position of the telescopic tube can be locked, completely avoiding tail wing flight movement and dimensional drift.

[0011] Furthermore, the wing folding mechanism is equipped with a wing limit detection component, which includes a folding limit sensor and an unfolding limit sensor. Both sensors are electrically connected to the UAV flight controller and are used to detect the maximum folding and storage position and the maximum unfolding working position of the wing folding section in real time, respectively, so as to realize immediate stopping when the deformation is in place and precise locking of the position, avoiding structural damage from overtravel collisions.

[0012] Furthermore, the telescopic assembly is equipped with a tail fin telescopic limit detection component, which includes a retraction limit sensor and an extension limit sensor. It establishes signal interaction with the UAV flight controller, collects the tail fin telescopic stroke position in real time, accurately controls the start and stop of telescopic movement, prevents overtravel wear and structural jamming, and ensures deformation accuracy and structural safety.

[0013] Furthermore, both the telescopic sleeve and the telescopic tube are integrally molded from high-strength carbon fiber composite material, resulting in low overall density and high specific strength. While meeting the requirements for structural stiffness, deformation resistance, and fatigue resistance, the self-weight of the deformed structure is minimized, which will not affect the flight endurance and power performance of the UAV and is suitable for lightweight flight requirements.

[0014] A control method for a compound-wing UAV with hovering, folding, and retracting functions, used to control any of the compound-wing UAVs described above, employs a safety interlocking logic of "steady-state pre-positioning, orderly linkage, closed-loop self-testing, and reverse reset," specifically including the following steps: Step S1: The UAV flight controller monitors the manual commands from the ground remote control terminal and the mode switching commands from the onboard autonomous flight program in real time. The preset working modes include the conventional fixed-wing cruise mode and the hovering narrow passage deformation mode.

[0015] Step S2: When the flight controller receives the instruction to switch to the hovering narrow passage mode, it first retrieves real-time data from the UAV's attitude sensor, altitude sensor, and gyroscope to perform a steady-state pre-verification: determining whether the UAV is in a stable hovering state; if the UAV is in a non-steady-state condition such as forward flight, side flight, climb, descent, or attitude tilt, the flight controller prioritizes independently controlling the power system and attitude loop to forcibly correct the UAV's attitude, speed, and altitude until the UAV enters a zero-speed, stable hovering state and locks its attitude before proceeding to the subsequent deformation process, thus eliminating the risk of dynamic flight deformation from the source.

[0016] Step S3: After the UAV passes the steady-state hovering verification, the flight controller outputs a control signal to start the folding drive motor. The folding section of the wing is driven to flip and fold vertically upwards through the worm gear reduction transmission pair. The wing limit detection component signals are collected in real time throughout the process. When the sensor detects that the folding section of the wing has reached the limit folding position, it immediately sends back a positioning signal. The flight controller then cuts off the power to the folding motor and locks it, completing the large-scale folding of the wing and compressing the UAV's wingspan by 50% to 60%.

[0017] Step S4: After the wing folding action is completed, the flight controller performs a single-step self-check to confirm that the wing has no overtravel, no jamming, and the locking position is normal. After the self-check is qualified, the telescopic drive motor is started, which drives the transmission screw to rotate. Through the screw slider, the telescopic tube and the tail fin are retracted axially towards the fuselage. The tail fin telescopic limit detection component signal is collected in real time. When the tail fin reaches the limit retraction position, the telescopic motor is immediately stopped and locked, completing the tail fin retraction. The longitudinal length of the UAV is reduced by 30% to 40%, and the whole aircraft enters the narrow passage state with the minimum envelope size.

[0018] Step S5: When the flight controller receives the command to exit deformation mode and switch to normal cruise mode, it executes a strict reverse ordered reset logic, prohibiting disordered reset: First, it prioritizes controlling the telescopic drive motor to reverse, driving the tail fin to extend axially and reset until the tail fin is fully extended and the sensor returns a complete reset signal, locking the tail fin cruise position; Second, after the tail fin reset self-test is passed, it starts the folding drive motor to reverse, driving the wing folding section to flip downwards and unfold until the wing is fully unfolded and the sensor returns a complete flattening signal; Third, after all deformation structures of the entire aircraft have completed reset, the flight controller performs an overall configuration self-test to confirm that the wings and tail fin are in standard cruise state, with no positional deviation or structural abnormalities; After the self-test is passed, the flight attitude and speed restrictions are lifted, allowing the UAV to enter high-speed fixed-wing cruise flight state.

[0019] Compared with the prior art, the present invention has outstanding substantive features and significant technological progress, and its specific beneficial effects are as follows: 1. Achieve bidirectional, large-scale adaptive deformation of the entire aircraft, resulting in a significant improvement in maneuverability in confined three-dimensional spaces. This invention pioneers a collaborative deformation architecture combining wing folding and tail axial retraction, breaking through the limitations of traditional single-dimensional deformation. It can stably achieve a 50%~60% compression of wingspan and a 30%~40% reduction in overall longitudinal length. Taking a mainstream model with a 2.5m wingspan and 1.8m overall longitudinal length as an example, after deformation, the wingspan is reduced to 1.1m and the overall longitudinal length is reduced to 1.15m. This allows for seamless adaptation to regular and irregular confined spaces such as 1.2m standard building windows, narrow alleyways, and gaps in jungle vegetation, completely solving the core pain point of traditional compound-wing UAVs' lack of small-envelope mobility.

[0020] 2. A unique upward-folding structure combined with dual mechanical self-locking significantly improves the safety and structural stability of deformation operations. Compared to the drawbacks of traditional downward-folding and rear-folding wings, which are susceptible to impacts and airflow interference, this invention employs an upward-folding vertical wing design, completely avoiding the structural impact risks associated with near-ground and through-gap operations. Simultaneously, it features a dual passive self-locking structure consisting of a worm gear self-locking pair and a lead screw thread self-locking pair. Once deformation is complete, the position is permanently locked upon power disconnection, eliminating the need for continuous power supply for shape maintenance. This effectively resists structural displacement and deformation failures caused by flight vibrations and turbulent disturbances, greatly enhancing flight reliability under complex operating conditions.

[0021] 3. The collaborative deformation combination possesses non-superimposed innovation and is precisely adapted to engineering practice scenarios. The combined deformation effect of the lateral compression of the wing and the longitudinal contraction of the tail in this invention is not a simple structural superposition, but a precise optimization design for the typical limited space dimensions of urban rescue and field inspection. The small envelope passage effect of this invention cannot be achieved by folding a single wing or contracting a single tail. This collaborative deformation architecture has strong originality and engineering practicality, and significantly expands the operational scenario boundaries of compound wing UAVs.

[0022] 4. Full-process safety interlocking closed-loop control completely eliminates the risk of misoperation and flight risks. This invention uses stationary stable hovering as the sole prerequisite for all deformation actions, eliminating the risk of accidental deformation during flight dynamics from the control logic level. At the same time, it adopts a unidirectional orderly deformation and reverse reset logic of "folding wings first, then retracting the tail, extending the tail first, then extending the wings," combined with full-stroke limit detection, step-by-step self-checking, and whole-aircraft re-checking mechanisms, to completely avoid the risks of failures such as asynchronous deformation, structural jamming, attitude loss of control, and power overload. The control logic is rigorous and highly fault-tolerant.

[0023] 5. Lightweight and highly adaptable, with excellent versatility and expandability. The core deformation structure uses carbon fiber composite materials, balancing high strength and lightweight, without compromising the drone's endurance, payload, or flight performance. The deformation ratio can be flexibly adapted to various composite-wing drones of different tonnages and sizes by adjusting the length of the folding section and the effective stroke of the telescopic tube. It has a wide range of adaptability, low modification difficulty, and extremely high industrialization and promotion value. Attached Figure Description

[0024] Figure 1 This is a top-view structural diagram of the UAV in cruise mode according to the present invention; Figure 2 This is a top-view structural diagram of the UAV in hovering folding and retracting mode according to the present invention; Figure 3 This is a schematic cross-sectional view of the wing folding mechanism of the present invention; Figure 4 This is a schematic cross-sectional view of the tail fin telescopic assembly of the present invention; Figure 5 This is a flowchart of the UAV control method of the present invention.

[0025] In the diagram: 101-wing, 102-fuselage, 103-tail, 104-telescopic boom, 105-wing folding section, 201-wing midsection, 202-wing folding section, 203-folding motor, 204-worm gear, 205-worm wheel, 206-folding shaft, 301-telescopic motor, 302-motor base, 303-lead screw, 304-telescopic tube sleeve, 305-telescopic tube, 306-lead screw slider. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only preferred 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 protection scope of the present invention.

[0027] This embodiment discloses a hovering deformable compound wing UAV adapted to medium and large-scale operation scenarios. In the normal cruise deployment state, the UAV has a wingspan of 2.5m and a longitudinal length of 1.8m from the nose to the trailing edge of the tail, which are the parameters of mainstream operation models in the industry.

[0028] like Figure 1 , Figure 2 As shown, in the normal cruise mode of the UAV, the wing 101 is fully horizontally flattened, the telescopic boom 104 is fully extended, and the tail fin 103 is in its maximum extended working position. The entire aircraft maintains its maximum aspect ratio, achieving optimal aerodynamic layout, which can meet the needs of high-speed cruise, long-distance inspection, and large-scale search and rescue operations. When a narrow, confined space is detected ahead, requiring small-envelope passage, the UAV autonomously or under control switches to a hovering deformation mode. After completing attitude stabilization locking, the wing folding section 202 rotates upward 90° around the folding axis 206, changing from horizontal flattening. When the aircraft is converted to a vertically retracted state, its wingspan is compressed from 2.5m to 1.1m, a compression ratio of 56%. At the same time, the telescopic motor 301 drives the lead screw 303 to rotate, causing the telescopic tube 305 and the tail fin 103 to retract axially towards the fuselage 102. The distance from the trailing edge of the tail fin to the tail is shortened from 1.0m to 0.65m, the overall longitudinal length is reduced to 1.15m, and the longitudinal dimension is reduced by 36%. After deformation, the regular envelope size of the aircraft can pass through a standard 1.2m×1.2m building window without obstruction, making it suitable for passage and operation in various narrow spaces.

[0029] like Figure 3 As shown, during the operation of the wing folding mechanism, the folding motor 203 outputs torque to drive the worm gear 204 to rotate at a constant speed. The worm gear 204 meshes with and drives the worm wheel 205 and the coaxially fixed folding shaft 206 to rotate synchronously, smoothly driving the wing folding section 202 to flip upwards and retract. When the wing folding section 202 reaches the vertical limit folding position, the limit detection component immediately triggers the positioning signal, and the flight controller controls the folding motor 203 to stop and cut off power immediately. Relying on the mechanical self-locking characteristics of the worm wheel and worm gear, the folding attitude is permanently locked, and there will be no loosening or deviation without external force intervention. When the UAV resets and unfolds, the folding motor drives in the opposite direction, which can realize the smooth flattening of the wing. After reaching the position, the horizontal cruise attitude is locked by the limit signal to ensure the aerodynamic stability of the flight.

[0030] like Figure 4As shown, when the tail fin telescopic assembly is working, the telescopic tube sleeve 304 is fixed to the tail of the fuselage and remains stationary. The telescopic motor 301 is fixed inside the fuselage through the shock-absorbing motor seat 302. During operation, it drives the lead screw 303 to rotate at a constant speed. The high-precision threaded transmission between the lead screw 303 and the lead screw slider 306 converts the rotational motion into the axial linear motion of the telescopic tube 305, accurately realizing the retraction and extension reset of the tail fin 103. The lead screw thread pair has a passive self-locking characteristic. After the extension is completed and the power is cut off, it can stably lock the extension position, effectively offsetting the displacement caused by flight vibration and airflow disturbance. The extension stroke is controlled by the limit detection component throughout the process to prevent overtravel failure and ensure deformation accuracy and structural safety.

[0031] like Figure 5 As shown, the control method of this invention adopts closed-loop safety interlock logic, and the core process strictly follows: mode command reception → UAV hovering steady-state verification → wing folding up to the correct position self-check → tail wing axial retraction to the correct position → narrow passage passage; reset cruise is strictly executed in reverse: tail wing extension reset self-check → wing flattening reset self-check → overall structure re-check → unlock cruise flight permission. The entire process is verified step by step and executed in an orderly manner, completely avoiding the risk of operational errors and structural damage.

[0032] It should be noted that the parameter range of 50% to 60% wingspan compression and 30% to 40% longitudinal length reduction described in this invention are preferred engineering parameters. Those skilled in the art can flexibly adapt the parameters by adjusting the length ratio of the wing folding section and the effective extension stroke of the telescopic tube according to the size of the UAV model and the requirements of the operation scenario. All technical solutions that adopt the core structure, deformation principle and control logic of this invention and fall within the protection parameter range of this invention are all within the protection scope of this invention.

Claims

1. A compound-wing unmanned aerial vehicle (UAV) with hovering, folding, and retracting functions, comprising a fuselage (102), a wing (101) mounted on the fuselage, a tail fin (103), and a telescopic rod (104) connecting the fuselage and the tail fin, characterized in that: The wing (101) includes a middle section (201) and a folding section (202). The middle section (201) is fixedly connected to the fuselage (102), and the folding section (202) is connected to the middle section (201) through a wing folding mechanism. The wing folding mechanism includes a folding motor (203), a worm (204), a worm wheel (205), and a folding shaft (206). The folding shaft (206) is horizontally arranged along the front-rear direction of the fuselage. The middle section (201) and the folding section (202) are hinged through the folding shaft (206). The worm wheel (205) is coaxially fixed on the folding shaft (206). The folding motor (203) is embedded inside the middle section (201). The output end of the folding motor (203) drives the worm (204) to rotate. The worm (204) meshes with the worm wheel (205) for transmission. The telescopic rod (104) includes a telescopic sleeve (304), a telescopic tube (305), a telescopic motor (301), a lead screw (303), and a lead screw slider (306). The telescopic sleeve (304) is fixed to the tail of the fuselage (102). The telescopic tube (305) is axially slidably inserted into the telescopic sleeve (304), and its rear end is fixedly connected to the tail fin (103). The telescopic motor (301) is fixed inside the fuselage (102) through a motor base (302). The lead screw (303) is drivenly connected to the output shaft of the telescopic motor (301) and extends into the telescopic tube (305). The lead screw slider (306) is fixed to the inner wall of the telescopic tube (305) and forms a threaded transmission engagement with the lead screw (303).

2. A compound-wing UAV with hovering, folding, and retracting functions according to claim 1, characterized in that: When the folding section (202) is folded upward to the extreme folding position and the telescopic tube (305) is retracted to the extreme retracted position, the wingspan of the UAV is compressed by 50% to 60% compared to the fully extended state, and the longitudinal length from the tail end of the fuselage to the trailing edge of the tail fin is reduced by 30% to 40% compared to the fully extended state.

3. A compound-wing UAV with hovering, folding, and retracting functions according to claim 1, characterized in that: The worm (204) and worm wheel (205) form a reverse self-locking transmission pair. After the folding motor (203) is de-energized, it can self-lock and fix the folding angle of the folding section (202), limiting positional offset and springback.

4. A compound-wing UAV with hovering, folding, and retracting functions according to claim 1, characterized in that: The lead screw (303) and the lead screw slider (306) form a self-locking threaded pair. The thread helix angle is less than the equivalent friction angle, so as to realize the power-off self-locking after the telescopic tube (305) is extended and retracted, and prevent the tail fin from flying erratically.

5. A compound-wing UAV with hovering, folding, and retracting functions according to claim 1, characterized in that: The wing folding mechanism is also equipped with a wing limit detection component, which includes a folding position sensor and an unfolding position sensor for detecting the extreme folding position and extreme unfolding position of the folding segment (202). The wing limit detection component is electrically connected to the UAV flight controller.

6. A compound-wing UAV with hovering, folding, and retracting functions according to claim 1, characterized in that: The telescopic rod (104) is equipped with a tail fin telescopic limit detection component, which includes a retracted position sensor and an extended position sensor for detecting the extreme retracted position and extreme extended position of the tail fin (103). The tail fin telescopic limit detection component is electrically connected to the UAV flight controller.

7. A compound-wing UAV with hovering, folding, and retracting functions according to claim 1, characterized in that: Both the telescopic sleeve (304) and the telescopic tube (305) are integrally molded from carbon fiber composite material.

8. A control method for a compound-wing unmanned aerial vehicle based on any one of claims 1-7, characterized in that, Includes the following steps: Step 1: The flight controller receives ground remote control commands or mode switching commands from the autonomous flight program in real time. Step 2: If the received command is to enter the hover folding passage mode, the flight controller first verifies the drone's flight status to determine whether the drone is in a stable hovering state. If the drone is in a non-hovering stable state, the power and attitude loops are adjusted first to enable the drone to quickly switch and lock into a stable hovering state. Step 3: After the hovering steady-state verification is passed, the flight controller starts the folding motor (203), which drives the wing folding section (202) to fold upward through the worm gear (204) and worm wheel (205) until the wing limit detection component sends a signal that the folding is in place. Then the folding motor (203) stops and locks, completing the 50%~60% compression of the wingspan. Step 4: After the wing folding action passes the self-test, the flight controller starts the telescopic motor (301), drives the lead screw (303) to rotate and drives the telescopic tube (305) and tail fin (103) to retract towards the fuselage through the lead screw slider (306) until the tail fin telescopic limit detection component sends a signal that it has retracted to the position. The telescopic motor (301) then stops and locks, completing the reduction of the longitudinal length of the entire aircraft by 30%~40%. Step 5: If the received instruction is to exit the hover folding passage mode and switch to cruise mode, the flight controller executes the reverse reset logic: first, it controls the telescopic motor (301) to drive the tail wing (103) to fully extend and reset. After the extension signal is verified and confirmed, it controls the folding motor (203) to drive the wing folding section (202) to fully unfold and reset. After the whole structure passes the self-check and there are no structural abnormalities, the high-speed cruise flight permission of the UAV is unlocked and it switches to fixed-wing cruise mode.

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