Distributed ducted rotor combined short-range vertical take-off and landing UAV and its control mode

Abstract

The present invention belongs to the field of aviation aircraft design, and discloses a short-distance vertical take-off and landing UAV with a distributed ducted rotor combination and its control mode. The UAV adopts a wing-body fusion layout, and the tail adopts a T-tail layout; the wings on both sides of the fuselage are divided into inner wings and outer wings from the inside to the outside; a wing-on fusion design is adopted, and a left-right symmetrical distributed ducted power module is set at the rear of the upper surface of the wing. The distributed ducted power module includes the same number of parallel ducted fans; a rotor strut is installed between the inner wing and the outer wing. The rotor strut adopts an anti-symmetric rod shape, with a traction rotor installed at the front end and a pusher rotor installed at the rear end; a servo is installed in the inner cavity of the rotor strut. The control modes include cruise mode, vertical take-off and landing mode, and short-distance take-off and landing mode. It can achieve short-distance take-off and landing and vertical take-off and landing, solving the multi-objective conflict problem of "limited take-off and landing site, insufficient load-bearing performance, and weak wind resistance" in plateau environments, and has practical engineering value.

Description

Technical Field

[0001] The present invention belongs to the field of aviation aircraft design, and in particular relates to a short-distance vertical take-off and landing UAV with a distributed ducted rotor combination and a control mode thereof. Background Art

[0002] The high altitude, low density, complex terrain, and strong winds of the plateau region pose significant challenges to the application of drones. Existing drone platforms all face significant limitations in plateau environments: multi-rotor drones face significant reductions in payload performance and limited flight speed; composite-wing drones suffer from insufficient payload capacity and poor wind stability; conventional taxiing drones struggle to adapt to the complex terrain's unique takeoff and landing requirements; and rocket-assisted and parachute-launched drones face high maintenance costs, high recovery risks, and low wing-loading designs, resulting in weak wind resistance and a limited window of effective operation.

[0003] To address the core challenge of UAV applications in plateau environments—the coordinated optimization of takeoff and landing performance and wind resistance—two technical approaches are currently being adopted: For short-range takeoff and landing UAVs, the lift efficiency is increased by increasing the wing area, while the takeoff and landing speed is reduced. The technical advantages are mainly reflected in larger payloads, higher cruising speeds, and better energy efficiency. However, due to the low wing load design and insufficient wind disturbance resistance, it is difficult to meet the full range of plateau application requirements. For vertical takeoff and landing aircraft, vertical takeoff and landing functions are achieved through power deflection or conversion. For tilt-rotor UAVs, for example, the mode conversion between vertical takeoff and landing and high-speed cruising is achieved through rotor tilting. However, the aerodynamic interference effect during the mode conversion is significant, and the complex aerodynamic coupling increases the difficulty of control system design. At the same time, as the altitude increases and the flight speed increases, the rotor force efficiency decreases significantly, resulting in limited payload capacity.

[0004] Both of these technical approaches face common challenges in plateau environments: achieving coordinated breakthroughs in payload performance, wind resistance, and all-terrain adaptability is difficult. Currently, there is an urgent need to develop a systematic solution through aerodynamic layout innovation and power system optimization, and to develop a short-range vertical takeoff and landing UAV with a distributed ducted rotor system and its control model. Summary of the Invention

[0005] One technical problem to be solved by the present invention is to provide a short-range vertical take-off and landing UAV with a distributed ducted rotor combination. Another technical problem to be solved by the present invention is to provide a control mode for a short-range vertical take-off and landing UAV with a distributed ducted rotor combination.

[0006] The distributed ducted rotor combination short-distance vertical take-off and landing UAV of the present invention adopts a wing-body fusion layout, and the tail adopts a T-tail layout;

[0007] The wings on both sides of the fuselage are divided into inner wings and outer wings from the inside to the outside. The rear part of the upper surface of the inner wing adopts a wing-on-wing fusion design and is equipped with a bilaterally symmetrical distributed ducted power module. The distributed ducted power modules on both sides include the same number of parallel ducted fans.

[0008] A rotor strut is installed between the inner and outer wings, with the central axis of the rotor strut parallel to the central axis of the fuselage; the rotor strut adopts an anti-symmetric rod shape, with the front facing the nose and the rear facing the tail; the front rotor is installed at the front end of the rotor strut, and the front rotor is a traction rotor, and the rear end is installed at the rear end, and the rear rotor is a pusher rotor; a servo is installed in the inner cavity of the rotor strut, and the chordwise position deviation between the center of the rotor strut and the center of gravity of the drone is no more than 5% of the average aerodynamic chord length of the wing; the servo simultaneously controls the corresponding front and rear rotors to tilt;

[0009] The tail consists of a horizontal tail and a vertical tail, and the horizontal tail is located at the top of the vertical tail.

[0010] Furthermore, the number of ducted fans in the distributed ducted power module is not less than 5; the distributed ducted power module on the left is divided into several ducted power units from the inside to the outside, and the distributed ducted power module on the right is divided into several corresponding ducted power units from the inside to the outside; the ducted power unit adopts distributed control to realize distributed differential control of the distributed ducted power module on the left and the distributed ducted power module on the right.

[0011] Furthermore, the installation angle of the ducted fan is 0°~15°, and the installation angle is the angle between the thrust line of the ducted fan and the central axis of the fuselage.

[0012] Furthermore, the process of selecting the installation angle is as follows:

[0013] S10. Based on the local chord length of the wing airfoil and the location of the distributed ducted power module, preliminarily determine the range of the installation angle. The ducted fan's inlet duct must blend with the curved surface of the wing's upper surface to prevent airflow separation and ensure that the ducted fan can effectively remove the boundary layer from the wing's upper surface.

[0014] S20. The installation angle is determined so that the thrust of the ducted fan has a lift component. The installation angle is ultimately determined based on the balance between the short takeoff and landing requirements and the load capacity of the UAV.

[0015] Furthermore, the front rotor and the rear rotor are both two-blade propellers or folding multi-blade propellers.

[0016] Furthermore, the tilt directions of the front rotor and the rear rotor are both downward, and the rotor tilt angle range is 0°~25°; the front rotor includes a left front rotor and a right front rotor that are bilaterally symmetrical, and the rear rotor includes a left rear rotor and a right rear rotor that are bilaterally symmetrical;

[0017] The four rotors adopt independent control mode or combined control mode; in independent control mode, the working status of the four rotors are independently controlled to jointly maintain the flight attitude of the UAV; in combined control mode, except for the rotation direction, the working status of the four rotors remains consistent, and the flight attitude of the UAV is jointly maintained through rudder control and distributed differential control of the distributed ducted power module.

[0018] The control modes of the distributed ducted rotor combination short-distance vertical take-off and landing UAV of the present invention include cruise mode, vertical take-off and landing mode and short-distance take-off and landing mode;

[0019] In cruise mode, the drone maintains a set flight speed at a set altitude, using ducted power as its sole source of power. The combined lift generated by the drone's fixed wings and the lift components provided by the distributed ducted power modules on both sides are sufficient to meet the drone's lift requirements. The power to the four rotors is reduced to completely shut down, and the front and rear rotors are retracted and fixed in the direction of the incoming airflow through a locking mechanism, reducing the drone's flight resistance.

[0020] In vertical take-off and landing mode, the rotor power is the main power and the ducted power is the auxiliary power; during vertical take-off, the four rotors serve as the only power source for take-off, and an independent control mode is adopted. The rotor inclination angle is zero, the power direction is vertically upward, and the drone is pulled to the set flight altitude and then hovers; then the rotors tilt, and a combined control mode is adopted to synchronously start the distributed ducted power module to obtain ducted power, and the drone enters the acceleration phase and accelerates to the set flight speed. During the acceleration process, the drone maintains the flight altitude or is in a climbing state; after the acceleration phase is completed, it switches to cruise mode; during vertical landing, the drone enters the deceleration phase, and the four rotors adopt an independent control mode. The rotor power is synchronously turned on and gradually increased to ensure that the drone descends slowly. At the same time, the ducted power is slowly turned off until it is completely turned off, and the drone is decelerated to a hovering state, and then the rotor power is continued to be reduced to lower the drone's altitude until the drone stops on the ground;

[0021] In the short takeoff and landing mode, the ducted power is the main power and the rotor power is the auxiliary power; during the takeoff process of the short takeoff and landing mode, the rotor power adopts a combined control mode, and the ducted power unit adopts distributed control. After the rotor pitch angle is deflected to the predetermined maximum angle, the ducted power and the rotor power work together, and the UAV is subjected to dual thrust, accelerating the taxiing and reducing the taxiing distance; the lift direction component of the ducted power and the rotor power effectively reduces the takeoff speed and increases the takeoff load; when the UAV is in the climbing state, the combined power of the ducted power and the rotor power increases the climbing speed of the UAV; climbing After the lift state is converted into the level flight stage, the proportion of rotor power is gradually reduced until the rotor power is turned off, the rotor pitch angle returns to zero and the drone enters cruise mode; during the landing process of the short take-off and landing mode, the drone gradually decelerates from the cruise state, the rotor power is enabled, the ducted power is reduced, and the total thrust in the forward direction is gradually reduced; when approaching the runway, the landing attitude of the drone is adjusted and the ducted power is further reduced or turned off. The rotor provides a backward drag component and an upward lift component, further reducing the landing speed of the drone; after entering the landing roll stage, the rotor power is reduced or turned off, and the landing gear brake is used to decelerate until the drone stops.

[0022] Furthermore, the rotor pitch angle in the climbing state is consistent with the angle of attack of the drone, which increases the lift component of the rotor power and improves the climbing efficiency of the drone; during the landing process, the rotor pitch angle is zero, and the rotor power provides a drag component. The size of the drag component depends on the flight attitude of the drone, and the rotor power is used to accelerate the drone's air deceleration process.

[0023] Furthermore, in a crosswind environment, the control mode provides control torque through distributed differential control of ducted power, thereby increasing the UAV's wind resistance.

[0024] The distributed ducted rotor combination short-distance vertical take-off and landing UAV and its control mode of the present invention are not constrained by complex terrain and have both vertical take-off and short-distance take-off and landing capabilities. In vertical take-off and landing mode, the power is provided by the rotor power. In short-distance take-off and landing mode, the combined power is provided by the ducted power and the rotor power. The ducted power is the main source of thrust, and after the rotor is tilted to the maximum angle, it provides the thrust component. The output value of the rotor power can be controlled in real time according to the runway length and take-off weight; in the case of low load and good runway conditions, the rotor power can be selectively started; in complex terrain such as plateaus or under heavy load conditions, the rotor power output can be increased according to the take-off and landing requirements of the UAV.

[0025] The distributed ducted rotor short-range vertical take-off and landing UAV and its control mode of the present invention have the following characteristics:

[0026] 1. Achieved takeoff and landing in complex conditions in plateau areas;

[0027] Vertical take-off and landing are no longer restricted by take-off and landing sites; short take-off and landing can reduce runway grade requirements under heavy load conditions and even enable highway take-off and landing.

[0028] 2. Increased wing loading and wind resistance performance;

[0029] The wing load is increased through the distributed ducted power increase; the wind resistance level is improved from level 1 to level 2 (corresponding to an increase in the wind speed threshold of 4m / s to 8m / s) through the distributed differential control of the ducted power; and the difficulty of distributed differential control of the ducted power is reduced by adopting a multi-unit distributed control strategy.

[0030] 3. The tilt-rotor is integrated and lightweight;

[0031] The rotor tilt adopts an angle limitation strategy and an antisymmetric rotor strut design. The front and rear rotors of the same strut share a servo, which reduces the structural burden caused by rotor tilt while meeting flight requirements.

[0032] The distributed ducted rotor combination short-distance vertical take-off and landing UAV and its control mode of the present invention realize short-distance take-off and landing and vertical take-off and landing; vertical take-off and landing are achieved by using rotor power, and short-distance take-off and landing in plateau environments and with large loads are achieved by using ducted power; ducted power effectively increases the wing loading, realizes distributed differential control, and enhances the wind resistance of the UAV; it solves the multi-objective conflict problem of "limited take-off and landing site - insufficient load performance - weak wind resistance" of UAVs in plateau environments, and has practical engineering value. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic structural diagram (stereoscopic diagram) of a short-distance vertical take-off and landing UAV with a distributed ducted rotor assembly according to the present invention;

[0034] Figure 2 A schematic diagram (top view) of the short-distance vertical take-off and landing UAV with a distributed ducted rotor assembly according to the present invention;

[0035] Figure 3 This is a schematic diagram of the rotor struts and rotor tilt in the short-distance vertical take-off and landing UAV with a distributed ducted rotor combination of the present invention.

[0036] In the figure, 1. Fuselage; 2. Inner wing; 3. Outer wing; 4. Horizontal tail; 5. Vertical tail; 6. Rotor strut; 7. Distributed ducted power module; 8. Front rotor; 9. Rear rotor; 10. Center of gravity of the UAV; 11. Servo;

[0037] 701. Ducted power unit I; 702. Ducted power unit II; 703. Ducted power unit III; 704. Ducted power unit IV; 705. Ducted power unit V; 706. Ducted power unit VI;

[0038] 801. Left front rotor; 802. Right front rotor;

[0039] 901. Left rear rotor; 902. Right rear rotor. DETAILED DESCRIPTION

[0040] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0041] like Figures 1 to 3 As shown, the distributed ducted rotor combination short-range vertical take-off and landing UAV of the present invention adopts a wing-body fusion layout, and the tail adopts a T-tail layout;

[0042] The wings on both sides of the fuselage 1 are divided into inner wings 2 and outer wings 3 from the inside to the outside. The rear portion of the upper surface of the inner wing 2 adopts a wing-on-wing fusion design and is provided with bilaterally symmetrical distributed ducted power modules 7. The distributed ducted power modules 7 on both sides include the same number of parallel ducted fans.

[0043] A rotor strut 6 is installed between the inner wing 2 and the outer wing 3, and the central axis of the rotor strut 6 is parallel to the central axis of the fuselage 1; the rotor strut 6 adopts an anti-symmetric rod shape, with the front facing the nose and the rear facing the tail; the front end of the rotor strut 6 is installed with a front rotor 8, which is a traction rotor, and the rear end is installed with a rear rotor 9, which is a pusher rotor; a steering gear 11 is installed in the inner cavity of the rotor strut 6, and the chordwise position deviation between the center of the rotor strut 6 and the center of gravity 10 of the UAV is no more than 5% of the average aerodynamic chord length of the wing; the steering gear 11 simultaneously controls the corresponding front rotor 8 and rear rotor 9 to tilt; while meeting the flight requirements of the UAV, the structural burden of the steering gear 11 on the UAV is reduced;

[0044] The tail comprises a horizontal tail 4 and a vertical tail 5 , wherein the horizontal tail 4 is located at the top end of the vertical tail 5 .

[0045] Furthermore, the number of ducted fans in the distributed ducted power module 7 is not less than 5; the distributed ducted power module 7 on the left is divided into several ducted power units from the inside to the outside, and the distributed ducted power module 7 on the right is divided into several corresponding ducted power units from the inside to the outside; the ducted power units adopt distributed control to realize distributed differential control of the distributed ducted power module 7 on the left and the distributed ducted power module 7 on the right.

[0046] Furthermore, the installation angle of the ducted fan is 0°~15°, and the installation angle is the angle between the thrust line of the ducted fan and the central axis of the fuselage 1.

[0047] Furthermore, the process of selecting the installation angle is as follows:

[0048] S10. Preliminarily determine the installation angle range based on the wing airfoil and the local chord length of the distributed ducted power module 7. This requires that the ducted fan's inlet duct blends with the curved surface of the wing's upper surface to prevent airflow separation and ensure that the ducted fan removes the boundary layer from the wing's upper surface.

[0049] S20. The installation angle is determined so that the thrust of the ducted fan has a lift component. The installation angle is ultimately determined based on the balance between the short takeoff and landing requirements and the load capacity of the UAV.

[0050] Furthermore, the front rotor 8 and the rear rotor 9 are both two-blade propellers or folding multi-blade propellers.

[0051] Furthermore, the tilt directions of the front rotor 8 and the rear rotor 9 are both downward, and the rotor tilt angle range is 0° to 25°; the front rotor 8 includes a left front rotor 801 and a right front rotor 802 that are symmetrical on both sides, and the rear rotor 9 includes a left rear rotor 901 and a right rear rotor 902 that are symmetrical on both sides;

[0052] The four rotors adopt independent control mode or combined control mode; in independent control mode, the working status of the four rotors are independently controlled to jointly maintain the flight attitude of the UAV; in combined control mode, except for the rotation direction, the working status of the four rotors remains consistent, and the flight attitude of the UAV is jointly maintained through rudder control and distributed differential control of the distributed ducted power module 7.

[0053] The control modes of the distributed ducted rotor combination short-distance vertical take-off and landing UAV of the present invention include cruise mode, vertical take-off and landing mode and short-distance take-off and landing mode;

[0054] In cruise mode, the drone maintains a set flight speed at a set altitude, with ducted power as the sole power source. The lift generated by the drone's fixed wings and the lift components provided by the distributed ducted power modules 7 on both sides are sufficient to meet the drone's lift requirements. The power of the four rotors is reduced to completely shut down, and the front rotor 8 and rear rotor 9 are retracted and fixed in the direction of the incoming airflow through the locking mechanism, reducing the drone's flight resistance.

[0055] In vertical take-off and landing mode, the rotor power is the main power and the ducted power is the auxiliary power; during vertical take-off, the four rotors serve as the only power source for take-off, and an independent control mode is adopted. The rotor inclination angle is zero, the power direction is vertically upward, and the drone is pulled to the set flight altitude and then hovers; then the rotor 9 tilts, and a combined control mode is adopted to synchronously start the distributed ducted power module 7 to obtain ducted power, and the drone enters the acceleration stage and accelerates to the set flight speed. During the acceleration process, the drone maintains the flight altitude or is in a climbing state; after the acceleration stage is completed, it switches to cruise mode; during vertical landing, the drone enters the deceleration stage, and the four rotors adopt an independent control mode. The rotor power is synchronously turned on and gradually increased to ensure that the drone descends slowly. At the same time, the ducted power is slowly turned off until it is completely turned off, and the drone is decelerated to a hovering state, and then the rotor power is continued to be reduced to lower the drone's altitude until the drone stops on the ground;

[0056] In the short takeoff and landing mode, the ducted power is the main power and the rotor power is the auxiliary power; during the takeoff process of the short takeoff and landing mode, the rotor power adopts a combined control mode, and the ducted power unit adopts distributed control. After the rotor pitch angle is deflected to the predetermined maximum angle, the ducted power and the rotor power work together, and the UAV is subjected to dual thrust, accelerating the taxiing and reducing the taxiing distance; the lift direction component of the ducted power and the rotor power effectively reduces the takeoff speed and increases the takeoff load; when the UAV is in the climbing state, the combined power of the ducted power and the rotor power increases the climbing speed of the UAV; climbing After the lift state is converted into the level flight stage, the proportion of rotor power is gradually reduced until the rotor power is turned off, the rotor pitch angle returns to zero and the drone enters cruise mode; during the landing process of the short take-off and landing mode, the drone gradually decelerates from the cruise state, the rotor power is enabled, the ducted power is reduced, and the total thrust in the forward direction is gradually reduced; when approaching the runway, the landing attitude of the drone is adjusted and the ducted power is further reduced or turned off. The rotor provides a backward drag component and an upward lift component, further reducing the landing speed of the drone; after entering the landing roll stage, the rotor power is reduced or turned off, and the landing gear brake is used to decelerate until the drone stops.

[0057] Furthermore, the rotor pitch angle in the climbing state is consistent with the angle of attack of the drone, which increases the lift component of the rotor power and improves the climbing efficiency of the drone; during the landing process, the rotor pitch angle is zero, and the rotor power provides a drag component. The size of the drag component depends on the flight attitude of the drone, and the rotor power is used to accelerate the drone's air deceleration process.

[0058] Furthermore, in a crosswind environment, the control mode provides control torque through distributed differential control of ducted power, thereby increasing the UAV's wind resistance.

[0059] Embodiment: The distributed ducted power modules 7 on the left and right sides of this embodiment respectively include 8 ducted fans, the outer diameter of the ducted fans is 120 mm, and the installation angle of the ducted fans is 9°.

[0060] like Figure 2 As shown, the eight ducted fans of the distributed ducted power module 7 on the left are divided into ducted power unit I 701, ducted power unit II 702 and ducted power unit III 703 from the inside to the outside, with 3, 2 and 3 ducted fans respectively; the distributed ducted power module 7 on the right is divided into corresponding ducted power unit IV 704, ducted power unit V 705 and ducted power unit VI 706 from the inside to the outside, with 3, 2 and 3 ducted fans respectively; through the precise control of the working status of the six power units, the distributed differential control of the ducted power is realized to provide the thrust required by the UAV.

[0061] like Figure 3 As shown, the front rotor 8 and the rear rotor 9 of this embodiment both use two-blade propellers, and the inclination angle of the front rotor 8 is θ 1 , the inclination angle of the rear rotor 9 is θ 2 , θ 1 = θ 2 The chordwise distance between the center of rotation of the front rotor 8 and the center of gravity of the drone 10 is The chord-wise distance between the rotation center of the rear rotor 9 and the center of gravity 10 of the UAV is , .

[0062] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the description and implementation methods. For those familiar with the art, all features disclosed in the present invention, or all steps in the disclosed methods or processes, except for mutually exclusive features and / or steps, can be combined in any way without departing from the principles of the present invention. The present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A short-range vertical take-off and landing UAV with a distributed ducted rotor assembly, characterized in that: The UAV adopts a wing-body fusion layout, and the tail adopts a T-tail layout; The wings on both sides of the fuselage (1) are divided into inner wings (2) and outer wings (3) from the inside to the outside; the rear portion of the upper surface of the inner wing (2) adopts a wing-on-wing fusion design, and is provided with a left-right symmetrical distributed ducted power module (7), and the distributed ducted power modules (7) on both sides include the same number of parallel ducted fans; A rotor strut (6) is installed between the inner wing (2) and the outer wing (3), and the central axis of the rotor strut (6) is parallel to the central axis of the fuselage (1); the rotor strut (6) adopts an anti-symmetric rod shape, with the front facing the nose and the rear facing the tail; the front end of the rotor strut (6) is installed with a front rotor (8), which is a traction rotor, and the rear end is installed with a rear rotor (9), which is a pusher rotor; a steering gear (11) is installed in the inner cavity of the rotor strut (6), and the chordwise position deviation between the center of the rotor strut (6) and the center of gravity (10) of the UAV is not greater than 5% of the average aerodynamic chord length of the wing; the steering gear (11) simultaneously controls the corresponding front rotor (8) and rear rotor (9) to tilt; The tail comprises a horizontal tail (4) and a vertical tail (5), wherein the horizontal tail (4) is located at the top of the vertical tail (5); The installation angle of the ducted fan is 0° to 15°, and the installation angle is the angle between the thrust line of the ducted fan and the central axis of the fuselage (1); The process of selecting the installation angle is as follows: S10. Based on the local chord length of the wing airfoil and the position of the distributed ducted power module (7), the range of the installation angle is preliminarily determined, requiring the air intake duct of the ducted fan to be integrated with the curved surface of the wing upper surface so that no airflow separation occurs, ensuring that the ducted fan can achieve boundary layer suction on the wing upper surface; S20. The installation angle is determined so that the ducted fan thrust has a lift component. The installation angle is ultimately determined based on the balance between the short takeoff and landing requirements and the payload capacity of the UAV.

2. The distributed ducted rotor short take-off and landing UAV according to claim 1, characterized in that: The number of ducted fans in the distributed ducted power module (7) is not less than 5; the distributed ducted power module (7) on the left is divided into a plurality of ducted power units from the inside to the outside, and the distributed ducted power module (7) on the right is divided into a plurality of corresponding ducted power units from the inside to the outside; the ducted power units adopt distributed control to realize distributed differential control of the distributed ducted power module (7) on the left and the distributed ducted power module (7) on the right.

3. The distributed ducted rotor short take-off and landing UAV according to claim 1, characterized in that: The front rotor (8) and the rear rotor (9) are both two-blade propellers or folding multi-blade propellers.

4. The distributed ducted rotor short take-off and landing UAV according to claim 1, characterized in that: The tilting directions of the front rotor (8) and the rear rotor (9) are both downward-facing directions, and the rotor tilt angle range is 0° to 25°; the front rotor (8) includes a left front rotor (801) and a right front rotor (802) that are symmetrical on both sides, and the rear rotor (9) includes a left rear rotor (901) and a right rear rotor (902) that are symmetrical on both sides; The four rotors adopt independent control mode or combined control mode; in the independent control mode, the working states of the four rotors are controlled independently to jointly maintain the flight attitude of the UAV; in the combined control mode, except for the rotation direction, the working states of the four rotors remain consistent, and the flight attitude of the UAV is jointly maintained by the rudder control and the distributed differential control of the distributed ducted power module (7).

5. A control mode for a distributed ducted rotor short take-off and landing UAV, which is used for the distributed ducted rotor short take-off and landing UAV according to any one of claims 1 to 4, characterized in that: The control modes include cruise mode, vertical take-off and landing mode, and short take-off and landing mode; In cruise mode, the UAV maintains a set flight speed at a set flight altitude, with ducted power as the only power source; the sum of the lift generated by the UAV's fixed wings and the lift components provided by the distributed ducted power modules (7) on both sides is sufficient to meet the UAV's lift requirements, reducing the power of the four rotors to completely shut down, and through the locking mechanism, the front rotor (8) and the rear rotor (9) are retracted and fixed in the direction of the incoming flow, reducing the UAV's flight resistance; In vertical take-off and landing mode, the rotor power is the main power and the ducted power is the auxiliary power; during vertical take-off, the four rotors are the only power source for take-off, and an independent control mode is adopted. The rotor inclination is zero, and the power direction is vertically upward. The drone is lifted to the set flight altitude and then hovers; then the rotor (9) tilts, and a combined control mode is adopted to synchronously start the distributed ducted power module (7) to obtain ducted power. The drone enters the acceleration phase and accelerates to the set flight speed. During the acceleration process, the drone maintains the flight altitude or is in a climbing state; after the acceleration phase is completed, it switches to the cruise mode; during vertical landing, the drone enters the deceleration phase, and the four rotors adopt an independent control mode. The rotor power is synchronously turned on and gradually increased to ensure that the drone descends slowly. At the same time, the ducted power is slowly turned off until it is completely turned off, and the drone is decelerated to a hovering state. Then the rotor power is further reduced to lower the drone's altitude until the drone stops on the ground; In the short takeoff and landing mode, the ducted power is the main power and the rotor power is the auxiliary power; during the takeoff process of the short takeoff and landing mode, the rotor power adopts a combined control mode, and the ducted power unit adopts distributed control. After the rotor pitch angle is deflected to the predetermined maximum angle, the ducted power and the rotor power work together, and the UAV is subjected to dual thrust, accelerating the taxiing and reducing the taxiing distance; the lift direction component of the ducted power and the rotor power effectively reduces the takeoff speed and increases the takeoff load; when the UAV is in the climbing state, the combined power of the ducted power and the rotor power increases the climbing speed of the UAV; climbing After the lift state is converted into the level flight stage, the proportion of rotor power is gradually reduced until the rotor power is turned off, the rotor pitch angle returns to zero and the drone enters cruise mode; during the landing process of the short take-off and landing mode, the drone gradually decelerates from the cruise state, the rotor power is enabled, the ducted power is reduced, and the total thrust in the forward direction is gradually reduced; when approaching the runway, the landing attitude of the drone is adjusted and the ducted power is further reduced or turned off. The rotor provides a backward drag component and an upward lift component, further reducing the landing speed of the drone; after entering the landing roll stage, the rotor power is reduced or turned off, and the landing gear brake is used to decelerate until the drone stops.

6. The control mode of the distributed ducted rotor short take-off and landing UAV according to claim 5 is characterized in that: The rotor pitch angle in the climbing state is consistent with the angle of attack of the drone, which increases the lift component of the rotor power and improves the drone's climbing efficiency; during landing, the rotor pitch angle is zero, and the rotor power provides a drag component. The size of the drag component depends on the drone's flight attitude, and the rotor power is used to accelerate the drone's air deceleration process.

7. The control mode of the distributed ducted rotor short take-off and landing UAV according to claim 5 is characterized in that: In a crosswind environment, the control mode provides control torque through distributed differential control of ducted power to increase the UAV's wind resistance.

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