Long-endurance land-air amphibious robot based on variable angle lift wing

Abstract

The application discloses a long-endurance land-air amphibious robot based on a variable-angle lift wing. The robot comprises a lift wing and a body. The lift wing is composed of a lift wing main body and two wing side plates on the sides. The side plates are provided with through insertion holes penetrating in the wing span direction. The body comprises two load-bearing carbon tubes, two variable attack angle mechanisms, a four-rotor power system and two variable-diameter wheel mechanisms. The carbon tubes are arranged in parallel inside the lift wing, and the end portions correspond to the through holes of the side plates. The variable attack angle mechanisms are arranged at the two ends of the carbon tubes and outside the side plates, pass through the through holes and are fixed with the end portions of the carbon tubes and are in transmission connection with the side plates, drive the wing to rotate around the carbon tube axis to adjust the angle of attack. The variable-diameter wheel mechanism is arranged below the variable attack angle mechanism, and the wheel diameter is adjustable, and is used for ground driving, obstacle crossing and flight contraction and drag reduction. The application has the significant advantages of significant reduction of cruising power consumption, balanced aerodynamic efficiency in a wide speed range, high structural integration and mutual non-interference of air and land modes, and effectively improves the endurance and environmental adaptability of cross-domain operation.

Description

Technical Field

[0001] This invention belongs to the field of amphibious robot technology, specifically relating to a long-endurance amphibious robot based on a variable-angle lifting wing. Background Technology

[0002] Amphibious robots are a type of cross-domain mobile platform capable of switching between air flight and ground movement modes, possessing unique value in tasks such as post-disaster rubble search and rescue, wilderness environmental exploration, urban security patrols, and military reconnaissance. In recent years, this field has attracted the attention of numerous research teams both domestically and internationally, accumulating a wealth of research results around key issues such as configuration innovation, motion mode switching, and cross-domain control.

[0003] From the perspective of ground movement implementation, existing solutions can be broadly categorized into two types. The first type relies on rotor thrust to directly drive ground movement, with typical examples including the "Pegasus" robot from the American robotics research company, "Drivocopter" from Caltech, and "RoFly" from Zhejiang University. The advantage of this type is its simple structure and low added weight, but the cost is also significant: the rotor must continuously output power during ground movement, resulting in high energy consumption, and it struggles to overcome even slightly higher obstacles. The second type involves adding a wheeled or tracked chassis, driven by an independent motor. Representative works include the transformable land-air robot from Beijing Institute of Technology, the wheel-and-pawl reconfigurable robot from Nanjing University of Science and Technology, and the detachable rescue robot developed with the participation of Tongji University. This type of solution offers better ground mobility and can handle more complex terrain, but the trade-off is that the chassis system itself is quite heavy. For small rotorcraft with limited payload margins, every gram of added weight directly reduces flight time. This is why most of the amphibious robots reported so far have an air endurance of only 10 to 30 minutes, which is indeed too short for actual deployment.

[0004] To improve endurance, some researchers have begun experimenting with adding fixed lifting wings to amphibious robots, hoping to alleviate the burden on the rotor during cruising by using the wings for propulsion. This idea itself is sound, but the fixed-wing approach has an unavoidable drawback: the effective angle of attack of the wing passively changes with the fuselage pitch attitude and flight speed. In other words, the wing's optimal operating point corresponds to only a specific speed, at which the lift-to-drag ratio is highest. However, as soon as the speed changes or the fuselage attitude adjusts, the wing's aerodynamic efficiency drops significantly. Furthermore, the interference of the rotor downwash on the flow field near the wing means that the lift gain achieved by the wing in actual flight is often much lower than theoretically expected. Based on publicly available literature, no one has yet proposed a solution for amphibious robots that can actively decouple the wing's aerodynamic angle of attack from the fuselage pitch attitude.

[0005] In summary, the core contradiction currently facing amphibious robots can be summarized as follows: they need to be able to move on the ground and fly for extended periods. However, existing configurations make too many compromises between these two goals, either sacrificing ground efficiency for lightweight design or burdening the aircraft with a heavy chassis for ground mobility. Furthermore, the introduction of fixed-lift wings introduces new coupling problems, making it difficult to fully realize the wing's lift potential. How to truly overcome the endurance bottleneck while maintaining high aerodynamic efficiency across the entire flight speed range, while ensuring ground mobility, is a pressing technical challenge in this field. Summary of the Invention

[0006] To address the problems existing in the background technology, this invention provides a long-endurance amphibious robot based on a variable-angle lifting wing, which solves the technical problems of short flight endurance, low aerodynamic efficiency across the entire flight envelope, and strong coupling between wing aerodynamic angle of attack and airframe pitch attitude in existing amphibious robots.

[0007] The technical solution adopted in this invention is:

[0008] I. A long-endurance amphibious robot based on a variable-angle lifting wing:

[0009] The system includes a lifting wing and a fuselage. The lifting wing includes a main body and two wing side plates respectively disposed on both sides of the main body. Each wing side plate has two through holes extending along the wingspan. The fuselage includes two load-bearing carbon tubes, two variable angle-of-attack mechanisms, a quadcopter power system, and two variable diameter wheel mechanisms. The two load-bearing carbon tubes are arranged parallel to each other along the wingspan inside the main body of the lifting wing, with the ends of the two load-bearing carbon tubes on the same side corresponding to the positions of the two through holes on the corresponding wing side plates. The two variable angle-of-attack mechanisms are respectively disposed at both ends of the load-bearing carbon tubes, and the main... The body is located on the outer side of the wing side plate on the corresponding side; each of the variable angle of attack mechanisms passes through the insertion hole on the corresponding side and is fixedly connected to the same side end of the two load-bearing carbon tubes, and is also connected to the wing side plate on the corresponding side for driving the lifting wing body to rotate around the axis of the two load-bearing carbon tubes to adjust the aerodynamic angle of attack of the lifting wing; the two variable diameter wheel mechanisms are respectively arranged below the variable angle of attack mechanism on the corresponding side, and each of the variable diameter wheel mechanisms is provided with a walking wheel with adjustable wheel diameter, which is used to enable the robot to travel quickly on flat ground, overcome obstacles in rugged or narrow terrain, and reduce aerodynamic drag when flying in the air.

[0010] The lifting wing also includes multiple wing support rods; the main body of the lifting wing is formed by an upper arc-shaped plate and a lower flat plate, and two wing side plates are respectively fixedly installed on both sides of the main body of the lifting wing. The main body of the lifting wing and the two wing side plates together form an internal cavity; the multiple wing support rods are arranged parallel to each other along the wingspan direction in the internal cavity, and the two ends of each wing support rod are respectively fixedly connected to the wing side plates on both sides.

[0011] Each variable angle of attack mechanism includes a drive servo, an aluminum alloy connector, and a servo disk. The aluminum alloy connector has a transverse base and two plug-in arms. The two plug-in arms protrude from the transverse base and face one side of the wing side plate. The two plug-in arms pass through the plug-in through holes on the corresponding side and are fixedly sleeved to the ends of two load-bearing carbon tubes. The transverse base is located on the outside of the wing side plate, and both ends of the transverse base are fixedly connected to the quadcopter power system. Each variable diameter wheel mechanism is detachably installed on the lower part of the transverse base of the corresponding side aluminum alloy connector. The drive servo is fixed in the middle of the transverse base, and the output shaft of the drive servo is arranged along the wingspan direction. The inner ring of the servo disk is fixedly connected to the output shaft of the drive servo, and the outer ring of the servo disk is fixedly connected to the wing side plate on the same side. The drive servo drives the wing side plate and the lifting wing body to rotate synchronously around the axis of the load-bearing carbon tubes through the servo disk.

[0012] Each of the aforementioned variable diameter wheel mechanisms includes a support leg, an auxiliary wheel, a travel drive motor, a hollow shaft, a wireless power supply transmitter coil, a wireless power supply receiver coil, a variable diameter servo motor, a central hub, a transmission servo disc, a connecting turntable, multiple sets of umbrella wheels, multiple connecting rods, and a rubber outer ring.

[0013] The upper end of the support leg is detachably mounted on the lower part of the transverse base of the corresponding aluminum alloy connector. An auxiliary wheel mounting arm is provided on the side of the support leg that is perpendicular to the wingspan direction. An auxiliary wheel is rotatably mounted on the end of the auxiliary wheel mounting arm.

[0014] The walking drive motor is fixedly installed on the inner side of the support leg, and the output shaft of the walking drive motor is arranged outward along the wingspan direction; the lower part of the support leg has a through hole that runs through the wingspan direction, and the hollow shaft is coaxially inserted into the through hole. One end of the hollow shaft is connected to the output shaft of the walking drive motor, and the other end of the hollow shaft extends to the outside of the support leg and is coaxially fixedly connected to the center hub.

[0015] The wireless power supply transmitter coil is fixedly installed around the mounting through hole on the outside of the support leg, and the wireless power supply receiver coil is coaxially embedded in the internal cavity of the hollow shaft; the variable diameter servo is fixedly installed at the center of the central hub, and the wiring harness of the variable diameter servo passes through the inside of the hollow shaft. One end of the wiring harness is electrically connected to the wireless power supply receiver coil, and the other end extends into the central hub and is electrically connected to the variable diameter servo.

[0016] The central hub is evenly provided with multiple radially extending guide grooves. The radial inner end of each set of umbrella wheels is correspondingly embedded in a guide groove, and can slide radially back and forth along the guide groove. The outer surface of all umbrella wheels is covered with a rubber outer ring.

[0017] The transmission servo disk and the connecting turntable are arranged coaxially along the outer side of the central hub. The inner ring of the transmission servo disk is fixedly connected to the output shaft of the variable diameter servo, and the outer ring of the transmission servo disk is fixedly connected to the connecting turntable. Multiple connecting rods are evenly hinged around the circumference of the connecting turntable, and the outer end of each connecting rod is correspondingly hinged to the radial inner end of a set of bevel wheels. The variable diameter servo drives the connecting turntable to rotate circumferentially through the transmission servo disk, and drives each set of bevel wheels to synchronously extend and retract radially along the guide groove through the connecting rod transmission, thereby realizing the switching of the wheel diameter between the minimum and maximum states.

[0018] The quadcopter power system includes four rotor arms and rotor power units respectively installed at the outer ends of each rotor arm; the two rotor arms located on the same side of the fuselage extend obliquely toward the front and rear sides of the fuselage respectively, and each rotor arm is arranged at an angle to the longitudinal axis of the fuselage in the top view direction, and the four rotor arms form an X-shaped symmetrical layout; the inner end of each rotor arm is fixed to the end of the transverse base of the corresponding side aluminum alloy connector.

[0019] The rotor power unit includes a motor mount, a drive motor, and a propeller; the motor mount is fixedly installed at the outer end of each rotor arm; the drive motor is fixed on the motor mount, the output shaft of the drive motor is arranged vertically, and the propeller is coaxially fixed on the output shaft of the drive motor.

[0020] II. A hierarchical control system employing a long-endurance amphibious robot:

[0021] The motion control module includes a motion control module and a remote control link; the motion control module includes a main controller, a secondary controller, a flight motion execution unit, and a ground motion execution unit; the flight motion execution unit includes a drive motor and a drive servo motor; the ground motion execution unit includes a walking drive motor and a variable diameter servo motor; the remote control link includes a data transmission device, a ground station, a first remote controller, and a second remote controller.

[0022] The main controller is communicatively connected to each drive motor to adjust the speed of each drive motor; the secondary controller is communicatively connected to each drive servo to adjust the output angle of the drive servo; the secondary controller is also communicatively connected to each travel drive motor to coordinate the control of the speed of the travel drive motors on both sides.

[0023] The data transmission device communicates with the ground station to transmit data, which is used for motion mode planning and operation status monitoring. The first remote controller communicates with the main controller and the secondary controller respectively. After observing the information from the ground station, the operator sends motion control commands to the main controller and the secondary controller through the first remote controller. The second remote controller communicates with the variable diameter servo and is used to directly control the variable diameter servo independently.

[0024] III. A method for feedforward decoupling control of wing aerodynamic angle of attack in a hierarchical control system:

[0025] S1. Real-time acquisition of aircraft pitch angle Substituting the preset aerodynamic angle-of-attack feedforward model, the deflection angle of the lifting wing relative to the fuselage is calculated. .

[0026] S2, based on the deflection angle Generate servo control signals to control the drive servos (13) on both sides to synchronously drive the lifting wings to deflect relative to the fuselage. The angle is adjusted to counteract the interference of changes in the aircraft's pitch attitude on the wing's aerodynamic angle of attack.

[0027] The aerodynamic angle-of-attack feedforward model is set according to the following formula:

[0028] ;

[0029] In the formula, The deflection angle of the lifting wing relative to the fuselage; The target wing's aerodynamic angle of attack; Preset the installation deviation angle for the lifting wing; The gain coefficient is controlled by the installation angle. This refers to the pitch angle of the aircraft, collected in real time.

[0030] The beneficial effects of this invention are:

[0031] 1. This invention utilizes a combination of a variable-angle lifting wing and a pitch-angle-attack feedforward decoupled control strategy to allow the wing to actively share the rotor load during the cruise phase. Field test results confirm this: at a cruise speed of 10 m / s, the overall power consumption is reduced by 43.34% compared to hovering. Powered by a 6S2P 21700 lithium battery (222 Wh) at 80% depth of discharge, a single charge can support 46.78 minutes of flight, corresponding to a range of approximately 28.07 km. In contrast, the endurance of most amphibious robots currently available is generally between 10 and 30 minutes.

[0032] 2. This invention utilizes a variable angle-of-attack mechanism to actively decouple the effective angle of attack of the wing from the pitch attitude of the aircraft, bypassing the inherent limitation of fixed angle-of-attack wings that only achieve optimal efficiency at a single speed point. Actual measurement data shows that within the cruise speed range of 8–12 m / s, the effective angle of attack of the wing can be stably maintained at 4°–12°, the overall lift-to-drag ratio is not less than 4.0, and the aerodynamic efficiency across the entire flight envelope is more balanced than that of the fixed angle-of-attack scheme.

[0033] 3. This invention employs a feedforward decoupled control architecture, isolating the wing's aerodynamic angle of attack from changes in the aircraft's pitch attitude. Attitude disturbances are not directly transmitted to the wing's lift characteristics. The rotor downwash is not a disturbance factor here; instead, it is used to delay wing stall, improving pitch stability during the transition phase of flight. The layered control design makes the wheel diameter switching between flight and ground operations smooth, and the system complexity does not become uncontrollable as functionality increases.

[0034] 4. This invention integrates the lifting wing into the fuselage rather than attaching it externally. The internal cavity of the lifting wing simultaneously houses the flight control components and the lithium battery, resulting in a compact structure without adding extra aerodynamic drag. The variable diameter wheel mechanism features a detachable design, retracting to its minimum diameter and retracting outside the lifting wing's projection during flight, thus not interfering with the airflow over the lifting wing surface. The variable diameter servo inside the hub is powered wirelessly, eliminating the need for slip rings or cables, and preventing the hassle of tangled wiring during wheel rotation. Attached Figure Description

[0035] Figure 1 This is a diagram of the robot's overall structure.

[0036] Figure 2 These are partial, enlarged, and exploded views of the variable angle of attack mechanism.

[0037] Figure 3 This is a partial and exploded view of the variable diameter wheel mechanism.

[0038] Figure 4 This is a diagram of the robot's motion patterns.

[0039] Figure 5 This is a schematic diagram of the first force acting on the robot.

[0040] Figure 6 This is a schematic diagram of the second force acting on the robot.

[0041] Figure 7 This is a diagram showing the change in lift of the robot as its flight speed changes, as illustrated in the example.

[0042] Figure 8 The diagram shows the power variation of the drone as the robot's flight speed changes, as illustrated in the example.

[0043] Figure 9This is an internal view of the prototype in the embodiment.

[0044] Figure 10 This is an external view of the prototype in the embodiment.

[0045] Figure 11 The diagram shows the state of the prototype during testing in the embodiment, where (a) is the static standby state, (b) is the takeoff preparation state, (c) is the vertical takeoff state, (d) is the hovering state, (e) is the forward flight state, and (f) is the vertical landing state.

[0046] Figure 12 This is a schematic diagram of the aerodynamic angle of attack feedforward decoupling control method for airfoils.

[0047] Figure 13 This is a flight path diagram for field testing.

[0048] Figure 14 This is a flight data graph showing the robot alternating between hovering and constant speed cruising at 12 m / s in the embodiment.

[0049] Figure 15 The diagram shows the verification results of three tests conducted on the robot under optimal flight conditions in the embodiment, where (a), (b), and (c) are sub-diagrams of the three tests, respectively.

[0050] In the diagram, the components are: 1. Lifting wing body; 2. Wing side plate; 3. Rotor arm; 4. Variable angle of attack mechanism; 5. Variable diameter wheel mechanism; 6. Wing support rod; 7. Propeller; 8. Drive motor; 9. Motor mount; 10. Lithium battery; 11. Flight control components; 12. Load-bearing carbon tube; 13. Drive servo; 14. Aluminum alloy connector; 15. Servo disc; 16. Support leg; 17. Walking drive motor; 18. Hollow shaft; 19. Auxiliary wheel; 20. Wireless power supply transmitter coil; 21. Wireless power supply receiver coil; 22. Variable diameter servo; 23. Center hub; 24. Transmission servo disc; 25. Connecting turntable; 26. Parachute wheel; 27. Linkage rod. Detailed Implementation

[0051] The present invention will now be described in more detail with reference to the accompanying drawings and embodiments. However, the present invention is not limited thereto. For those skilled in the art, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention. Contents not described in detail in this specification are prior art known to those skilled in the art.

[0052] like Figure 1As shown, the long-endurance amphibious robot of this embodiment includes a lifting wing and a fuselage. The lifting wing includes a lifting wing body 1 and two wing side plates 2 respectively disposed on both sides of the lifting wing body 1. Each wing side plate 2 has two through holes extending along the wingspan. The fuselage includes two load-bearing carbon tubes 12, two variable angle of attack mechanisms 4, a quadcopter power system, and two detachable variable diameter wheel mechanisms 5. The two load-bearing carbon tubes 12 are arranged parallel to each other along the wingspan inside the lifting wing body 1, and the ends of the two load-bearing carbon tubes 12 on the same side correspond to the positions of the two through holes on the corresponding wing side plates 2. The two variable angle of attack mechanisms 4 are respectively disposed at both ends of the load-bearing carbon tubes 12, and The main body of each variable angle of attack mechanism 4 is located on the outer side of the corresponding wing side plate 2; each variable angle of attack mechanism 4 passes through two insertion holes on the corresponding side and is fixedly connected to the same side end of the two load-bearing carbon tubes 12, and the variable angle of attack mechanism 4 is connected to the corresponding wing side plate 2 for driving the lifting wing body 1 to rotate around the axis of the two load-bearing carbon tubes 12 to adjust the aerodynamic angle of attack of the lifting wing; two variable diameter wheel mechanisms 5 are respectively set below the variable angle of attack mechanism 4 on the corresponding side, and each variable diameter wheel mechanism 5 is equipped with a walking wheel with adjustable wheel diameter, which is used to enable the robot to travel quickly on flat ground, overcome obstacles in rugged or narrow terrain, and shrink the wheel diameter to reduce aerodynamic drag when flying in the air.

[0053] The lifting wing also includes multiple wing support rods 6; the lifting wing body 1 includes an upper arc-shaped plate and a lower flat plate, which are enclosed by the upper arc-shaped plate and the lower flat plate. Two wing side plates 2 are fixedly installed on both sides of the lifting wing body 1. The lifting wing body 1 and the two wing side plates 2 together enclose and form an internal cavity; multiple wing support rods 6 are arranged parallel to each other along the wingspan direction in the internal cavity. The two ends of each wing support rod 6 are fixedly connected to the wing side plates 2 on both sides to enhance the structural rigidity of the lifting wing body 1.

[0054] In practice, the main body of the lifting wing 1 adopts a rectangular (top view) wing.

[0055] The cavity also houses a lithium battery 10 and a flight control assembly 11. The lithium battery 10 is fixedly mounted on the lower flat plate, and the flight control assembly 11 is fixedly mounted on the load-bearing carbon tube 12. The flight control assembly 11 integrates a main controller and a secondary controller. The power distribution board and step-down module are integrated and arranged in the cavity, forming a power module together with the lithium battery 10.

[0056] like Figure 2As shown, each variable angle of attack mechanism 4 includes a drive servo 13, an aluminum alloy connector 14, and a servo disc 15. The aluminum alloy connector 14 has a transverse base and two plug-in arms. The two plug-in arms protrude vertically from the transverse base and face one side of the wing side plate 2, extending into the cavity along the wingspan direction. The two plug-in arms pass through two plug-in through holes on the corresponding sides and are fixedly sleeved to the same side ends of the two load-bearing carbon tubes 12. The transverse base is located on the outside of the wing side plate 2, and both ends of the transverse base are fixedly connected to the quadcopter power system. Each variable diameter wheel mechanism 5 is detachably mounted. The variable diameter wheel mechanism 5 is installed on the lower part of the transverse base of the corresponding aluminum alloy connector 14 and extends downward, and is provided with a walking wheel that can be adjusted between the minimum wheel diameter and the maximum wheel diameter; the body of the drive servo motor 13 is fixed in the middle of the transverse base, and the output shaft of the drive servo motor 13 is arranged along the wingspan direction; the inner ring of the servo disk 15 is fixedly connected to the output shaft of the drive servo motor 13, and the outer ring of the servo disk 15 is fixedly connected to the wing side plate 2 on the same side; the drive servo motor 13 drives the wing side plate 2 and the lifting wing body 1 to rotate synchronously around the axis of the load-bearing carbon tube 12 through the servo disk 15.

[0057] Specifically, the two ends of the transverse base extend outwards and tilts towards the front and rear of the fuselage, respectively, so that the rotor arms 3 installed at its ends are arranged in an X-shape symmetrical arrangement.

[0058] Specifically, when the output shaft of the drive servo motor 13 rotates, it drives the inner ring of the servo disk 15 to rotate; the outer ring of the servo disk 15 is fixedly connected to the wing side plate 2, and the wing side plate 2 and the lifting wing body 1 are fixedly integrated. Therefore, the rotational motion of the output shaft of the drive servo motor 13 is transmitted to the wing side plate 2 through the servo disk 15, ultimately driving the entire lifting wing to rotate around the axis of the load-bearing carbon tube 12, while the load-bearing carbon tube 12, the aluminum alloy connector 14, and the rotor arm 3 remain stationary.

[0059] In practice, the plug-in arm and the load-bearing carbon tube 12 are arranged coaxially, and together they form the rotation pivot of the wing. The aluminum alloy connector 14 is an integrated molding structure, and the transverse base integrates the wing hinge position, the servo mounting cavity, the rotor arm 3 mounting position and the wheel connection position, which respectively connect the wing side plate 2, the drive servo 13, the inner end of the rotor arm 3 and the variable diameter wheel mechanism 5.

[0060] like Figure 3 As shown, each variable diameter wheel mechanism 5 includes a support leg 16, an auxiliary wheel 19, a walking drive motor 17, a hollow shaft 18, a wireless power supply transmitter coil 20, a wireless power supply receiver coil 21, a variable diameter servo motor 22, a central hub 23, a transmission servo disc 24, a connecting turntable 25, multiple sets of umbrella wheels 26, multiple connecting rods 27, and a rubber outer ring.

[0061] The upper end of the support leg 16 is detachably mounted on the lower part of the transverse base of the corresponding aluminum alloy connector 14. The support leg 16 extends along one side perpendicular to the wingspan direction and is provided with an auxiliary wheel 19 mounting arm. An auxiliary wheel 19 is rotatably mounted at the end of the auxiliary wheel 19 mounting arm.

[0062] The body of the walking drive motor 17 is fixedly installed on the inner side of the support leg 16, and the output shaft of the walking drive motor 17 is arranged outward along the wingspan direction. The lower part of the support leg 16 has a through hole that runs through the wingspan direction. The hollow shaft 18 is coaxially inserted into the through hole. One end of the hollow shaft 18 is connected to the output shaft of the walking drive motor 17, and the other end of the hollow shaft 18 extends to the outside of the support leg 16 and is coaxially fixedly connected to the center hub 23.

[0063] The wireless power supply transmitter coil 20 is fixedly installed around the mounting through hole on the outside of the support leg 16, and the wireless power supply receiver coil 21 is coaxially embedded in the internal cavity of the hollow shaft 18. The variable diameter servo 22 is fixedly installed at the center of the center hub 23. The wiring harness of the variable diameter servo 22 is arranged inside the hollow shaft 18. One end of the wiring harness is electrically connected to the wireless power supply receiver coil 21, and the other end extends into the center hub 23 and is electrically connected to the variable diameter servo 22. This allows the wiring harness of the variable diameter servo 22 to be buried inside the hollow shaft 18, obtaining power and control signals wirelessly, thereby avoiding the wiring tangling problem when the wheel rotates. [Specifically, the wiring harness includes power supply lines and signal lines.]

[0064] The central hub 23 is evenly provided with multiple radially extending guide grooves. The radial inner end of each set of umbrella wheels 26 is correspondingly embedded in a guide groove, so that the umbrella wheels 26 can slide radially back and forth along the guide grooves. The outer surface of all umbrella wheels 26 is covered with a rubber outer ring.

[0065] The transmission rudder disk 24 and the connecting turntable 25 are arranged coaxially outward along the axial direction on the outer side of the central hub 23. The inner ring of the transmission rudder disk 24 is fixedly connected to the output shaft of the variable diameter servo 22, and the outer ring of the transmission rudder disk 24 is fixedly connected to the connecting turntable 25. Multiple connecting rods 27 are evenly hinged around the circumference of the connecting turntable 25. The inner end of each connecting rod 27 is hinged to the connecting turntable 25, and the outer end of each connecting rod 27 is correspondingly hinged to the radial inner end of a set of bevel wheels 26. The variable diameter servo 22 drives the connecting turntable 25 to rotate circumferentially through the transmission rudder disk 24, and drives each set of bevel wheels 26 to synchronously extend and retract radially along the guide groove through the connecting rods 27, thereby realizing the switching of the wheel diameter between the minimum and maximum states.

[0066] Specifically, in the case of high-speed driving on flat ground, the parachute wheel 26 of the variable diameter wheel mechanism 5 retracts to the minimum wheel diameter state, and the auxiliary wheel 19 assists in achieving stable driving; in the case of obstacle crossing in rugged or narrow terrain, the parachute wheel 26 unfolds to the maximum wheel diameter state; in the case of flight, the parachute wheel 26 maintains the minimum wheel diameter state, and the entire variable diameter wheel mechanism 5 is located outside the projection of the lifting wing, so as not to interfere with the airflow field on the surface of the lifting wing body 1.

[0067] The quadcopter power system includes four rotor arms 3 and rotor power units installed at the outer ends of each rotor arm 3. The two rotor arms 3 located on the same side of the fuselage extend horizontally outward toward the front and rear sides of the fuselage, respectively, and each rotor arm 3 is arranged at an angle to the longitudinal axis of the fuselage in the top view direction. The four rotor arms 3 form an X-shaped symmetrical layout in the top view direction. The inner end of each rotor arm 3 is fixed to the end of the transverse base of the corresponding aluminum alloy connector 14.

[0068] The rotor power unit includes a motor mount 9, a drive motor 8, and a propeller 7; the motor mount 9 is fixedly installed at the outer end of each rotor arm 3; the drive motor 8 is fixed on the motor mount 9, the output shaft of the drive motor 8 is arranged vertically and perpendicular to the rotor arm 3, and the propeller 7 is coaxially fixed on the output shaft of the drive motor 8.

[0069] Furthermore, the quadcopter power system also includes four electronic speed controllers (ESCs), each fixed to the corresponding rotor arm 3 or motor mount 9; the input of the ESC is connected to the power supply, the output is connected to the drive motor 8, and the signal is connected to the main controller.

[0070] This embodiment conducted the following experiments regarding the selection of lifting wings:

[0071] The airfoil of the lifting wing plays a decisive role in the aerodynamic performance of the robot. Based on the lift enhancement capability and the size and space constraints of the robot, the following requirements for the selection of lifting wings are proposed: (1) High lift requirement: The operating speed of the lifting wing-enhanced UAV during level flight cruise should not exceed 15 m / s, and is generally stable at 8~12 m / s. The lifting wing should be able to provide at least 10~15N of lift gain. (2) Low drag requirement: During the level flight cruise of the lifting wing-enhanced UAV, the greater the drag of the lifting wing, the greater its noise. In order to minimize the additional drag and reduce the energy consumption of the whole machine, the lifting wing should have good low drag characteristics to ensure that the lifting wing has a high lift-to-drag ratio. (3) Low pitch moment requirement: The pitch moment of the lifting wing should be low to avoid excessive trim loss. For low-speed aircraft, especially for long-endurance low-speed UAVs in level flight, there are two parameters that determine their flight state, namely speed and altitude. The Reynolds number can characterize these two quantities.

[0072] Table 1. Comparison of Airfoil Performance Parameters:

[0073] The GOE 384 has a range of applicable angles of attack second only to the NACA 2410, with an optimal range of 8° to 12°, making it suitable for low-speed UAVs.

[0074] As shown in Table 1, both GOE 384 and MH 114 have a maximum lift coefficient exceeding 1.8, indicating excellent lift performance. Considering the overall design requirements, this embodiment selects the GOE 384 airfoil for the lifting wing. The wing chord length is determined to be 510mm, the span to be 400mm, and the wing projected area S to be 0.204m². 2 Experimental verification showed that, in this embodiment, the optimal effective angle of attack for the GOE 384 lifting wing target is 10° for subsequent aerodynamic angle of attack feedforward decoupling control.

[0075] This embodiment also provides a hierarchical control system for a long-endurance amphibious robot, including:

[0076] The motion control module includes a main controller, a secondary controller, a flight motion execution unit, and a ground motion execution unit. The flight motion execution unit includes a drive motor 8 and a drive servo motor 13. The ground motion execution unit includes a walking drive motor 17 and a variable diameter servo motor 22. The remote control link includes a data transmission device, a ground station, a first remote controller, and a second remote controller.

[0077] Both the main controller and the secondary controller are integrated inside the flight control assembly 11 and are fixedly installed together with the flight control assembly 11 on the load-bearing carbon tube 12 inside the wing cavity.

[0078] The main controller is connected to each drive motor 8 via an electronic speed controller (ESC) to adjust the speed of each drive motor 8 and achieve closed-loop control of the overall flight attitude and trajectory. The secondary controller is connected to each drive servo motor 13 to output control signals to adjust the output angle of the drive servo motor 13 in real time and adjust the aerodynamic angle of attack of the wing to a preset value. The secondary controller is also connected to each walking drive motor 17 to coordinate the control of the speed of the walking drive motors 17 on both sides, so as to realize the robot's forward, backward and turning movements on the ground.

[0079] The data transmission equipment is communicatively connected to the ground station and the sensor detection module. The data transmission equipment receives the data collected by the sensor detection module and transmits it to the ground station, which is used for motion mode planning and operation status monitoring. The first remote controller is communicatively connected to the main controller and the secondary controller through the first set of receivers. After the operator observes the planned motion mode and the actual operation status at the ground station, the first remote controller sends motion control commands to the main controller and the secondary controller after being analyzed by the first set of receivers. The second remote controller is communicatively connected to the variable diameter servo 22 through the second set of receivers, and is used to directly control the variable diameter servo 22 to realize wheel diameter switching.

[0080] Furthermore, the hierarchical control system also includes a sensing and detection module, comprising an external sensing module and an internal sensing module; the external sensing module includes GPS and a camera gimbal, used to acquire external environmental information such as GPS data and environmental images; the internal sensing module includes an IMU and a barometer, used to sense internal information of the amphibious robot, such as its pitch angle.

[0081] GPS, camera gimbal, IMU, and barometer are all fixedly mounted on the robot. The data collected by the sensor detection module is divided into two paths: one path is transmitted to the main controller and the secondary controller for closed-loop control of flight attitude and ground movement; the other path is transmitted to the data transmission equipment and sent back to the ground station for real-time monitoring.

[0082] Furthermore, the hierarchical control system also includes a power supply module. The power supply module includes a lithium battery 10, a power distribution board, and a step-down module; the lithium battery 10 is connected to the power distribution board, and the output of the power distribution board is divided into a power supply branch and a low-voltage power supply branch.

[0083] The power supply branch directly supplies power to the ESC corresponding to each rotor, and the ESC then supplies power to the corresponding drive motor 8. The power supply branch also supplies power to the travel drive motor 17.

[0084] After being stepped down by the step-down module, the low-voltage power supply branch supplies power to the main controller, the secondary controller, the sensor detection module, and the drive servo motor 13, and also supplies power to the wireless power supply transmitter coil 20. The wireless power supply transmitter coil 20 transmits power to the wireless power supply receiver coil 21 through electromagnetic coupling, and then the wireless power supply receiver coil 21 supplies power to the variable diameter servo motor 22 built into the wheel hub. This adapts to the different voltage requirements of different hardware and the contactless power supply requirements of rotating parts, avoiding the problem of wire harness tangling during wheel rotation.

[0085] Robot movement patterns such as Figure 4 As shown, in the ground high-speed driving mode, the robot's parachute wheels retract to their minimum diameter; in the ground obstacle-crossing driving mode, the robot's parachute wheels open to their maximum diameter to improve obstacle-crossing ability; when flying in the air, the robot's parachute wheels always maintain their minimum diameter. When the robot enters cruise flight mode from hovering, the wing's aerodynamic angle of attack is actively adjusted to keep the robot in the optimal lift-to-drag ratio state throughout flight.

[0086] Furthermore, the workflow of the hierarchical control system in this embodiment is as follows:

[0087] 1) System startup: The robot is powered on, the main controller and the auxiliary controller are initialized and complete self-tests, the sensors in the sensing and detection module (including IMU, barometer, GPS and camera pan-tilt unit) are initialized and self-tested, and the ground station, the first remote controller and the second remote controller establish communication connections with the robot respectively.

[0088] 2) Environmental Identification and Motion Mode Decision-Making: Environmental identification is accomplished collaboratively by GPS, IMU, and a camera pan-tilt unit within the sensor detection module. GPS provides the robot's location information, the IMU provides real-time attitude information, and the camera pan-tilt unit provides images of the surrounding environment. The environmental identification process involves deciding on the appropriate motion mode based on the current environment: flight mode for open airspace, small-wheel-diameter driving mode for flat terrain, and large-wheel-diameter driving mode for rugged or confined spaces. Environmental identification information is transmitted back to the ground station via a data transmission device, allowing operators to determine the robot's motion mode. An appropriate motion mode is crucial for maximizing the robot's performance and is also an important means of protecting the robot.

[0089] 3) Control command issuance: After the motion mode decision is completed, the operator issues control commands to the main controller and the auxiliary controller through the first remote controller. The commands are parsed by the first set of receivers and then recognized and executed by the main controller and the auxiliary controller. The operator issues wheel diameter switching commands to the variable diameter servo 22 through the second remote controller. The commands are parsed by the second set of receivers and then recognized and executed by the variable diameter servo 22, thereby realizing the switching and control of motion modes.

[0090] 4) Motion execution: After parsing the received control signals, the main controller and the auxiliary controller output control signals to the corresponding actuators. The main controller adjusts the speed of each drive motor 8 through the electronic speed controller, and the auxiliary controller adjusts the output angle of each drive servo motor 13, the speed of each walking drive motor 17, and the rotation angle of the variable diameter servo motor 22, so as to drive the robot to complete the corresponding flight action, wing aerodynamic angle of attack adjustment, ground walking or wheel diameter switching action.

[0091] 5) Status Feedback and Closed-Loop Control: During robot movement, the sensing module collects data in real time and outputs it in two paths: one path is transmitted to the main controller and the auxiliary controller for closed-loop control of flight attitude and ground motion (for example, in flight motion control, the IMU provides real-time feedback of the robot's attitude to the main controller, which then uses an embedded control algorithm to perform closed-loop adjustment of the speed of each drive motor 8); the other path is transmitted to the data transmission equipment and sent back to the ground station for real-time monitoring by the operator. Based on the returned position information, attitude information, and environmental image information, combined with the task execution progress, the operator judges the task status and can change or stop the current task at any time via the first remote controller.

[0092] 6) Data recording: During the operation of the robot, the data recorded in real time by the sensing and detection module (including position, attitude, image and raw data of various sensors) is automatically saved to the storage medium inside the flight control component 11 for subsequent mission review, debugging and improvement work.

[0093] 7) Mission Completion: After the robot returns to the designated position, it is powered off and the communication links with the ground station and remote controller are disconnected. The saved log data is analyzed and processed after the mission for system performance evaluation and subsequent optimization.

[0094] This embodiment constructs a dynamic model of the robot, and analyzes the forces acting on it during aerial motion, as follows: Figure 5 and Figure 6 As shown, where (i=1~4) represents the thrust provided by rotor power systems 1~4; (i=1~4) represents the torque generated by rotor power systems 1~4; L is the lift of the entire aircraft; D is the drag of the entire aircraft; G is the weight of the entire aircraft; x, y, z are the body coordinate system; u, v, w are the velocities on each axis of the body coordinate system; Fx, Fy, Fz are the pull forces on each axis of the body coordinate system; p, q, r are the torques on each axis of the body coordinate system. For the wing's aerodynamic angle of attack; This is the sideslip angle. Figure 6 The yellow dashed line is the chord of the main body 1 of the lifting wing.

[0095] A dynamic model of the robot is constructed, and the final horizontal forward flight power of the entire machine is set according to the following formula:

[0096] ;

[0097] in, For flight power; Battery voltage; This is the battery discharge current; For the weight of the entire machine; The pitch angle of the aircraft; This provides lift for the entire machine; For the wing's aerodynamic angle of attack; air density; The rotor disk area; For flight speed; The induced velocity is the speed at which the rotor's rotation attracts airflow.

[0098] Based on the above formula, and taking a fuselage weight of 3.5 kg as a reference, the wing area is 0.2 m². 2 Then, as the robot gradually increases its speed from hovering to a flight speed of 15 m / s, observe the relationship between lift and robot power. Figure 7 and Figure 8 The changes in lift of the robot and the changes in power of the drone as the flight speed changes are described respectively. Figure 8This indicates that when the robot's flight speed increases to 12 m / s, due to the lift-enhancing effect of the wings, the robot's power will decrease to 47% of that in the hovering state. In other words, the robot can effectively reduce flight power. This power reduction trend becomes more significant as the flight speed increases.

[0099] In this embodiment, a prototype was manufactured according to the above structural description. The internal and external views of the prototype are shown below. Figure 9 and Figure 10 As shown.

[0100] This embodiment also includes flight testing of the prototype, and the state diagram during the test is as follows. Figure 11 As shown, (a) is the static standby state, (b) is the takeoff preparation state, (c) is the vertical takeoff state, (d) is the hovering state, (e) is the forward flight state, and (f) is the vertical landing state.

[0101] This embodiment also provides a wing aerodynamic angle-of-attack feedforward decoupling control method for a hierarchical control system, characterized by being implemented according to the following steps:

[0102] S1. Real-time acquisition of aircraft pitch angle Substituting the preset aerodynamic angle-of-attack feedforward model, the deflection angle of the lifting wing relative to the fuselage is calculated. ;

[0103] S2, based on the deflection angle Generate servo control signals to control the drive servos (13) on both sides to synchronously drive the lifting wings to deflect relative to the fuselage. The angle is adjusted to counteract the interference of changes in the aircraft's pitch attitude on the wing's aerodynamic angle of attack, thereby achieving decoupled control of the wing's aerodynamic angle of attack and the aircraft's pitch angle.

[0104] The robot's overall power consumption in cruise mode should be at least 40% lower than in hover mode. Regarding the wing's aerodynamic angle of attack and the fuselage's pitch angle, this invention proposes an aerodynamic angle of attack feedforward model to decouple the wing's aerodynamic angle of attack from the fuselage pitch angle, aiming to quantify the aerodynamic benefits of the lifting wing. The theoretical wing aerodynamic angle of attack involves the induced downwash angle. However, actual measurement of this inevitably requires a complex sensor array. Therefore, to simplify engineering verification, dynamic aspects were ignored. The applied aerodynamic angle-of-attack feedforward model directly compensates for the measurable pitch angle. The aerodynamic angle-of-attack feedforward model of the present invention is set according to the following formula:

[0105] ;

[0106] In the formula, The deflection angle of the lifting wing relative to the fuselage; The target wing's aerodynamic angle of attack; Preset the installation deviation angle for the lifting wing; The gain coefficient is controlled by the installation angle. This refers to the pitch angle of the aircraft, which is collected in real time.

[0107] like Figure 12 This demonstrates the principle of the wing aerodynamic angle-of-attack feedforward decoupling control method of the present invention. The IMU acquires the real-time airframe pitch angle. The inverse value of that angle Multiply by proportional gain In addition to the target wing's aerodynamic angle of attack And subtract the preset installation deviation angle of the lifting wing Obtain the deflection angle of the lifting wing relative to the fuselage. Subsequently, the deflection angle The command drives the secondary controller to control the drive servos 13 on both sides to move synchronously and deflect by an angle. The commands are filtered through a first-order inertial element to ensure a smooth servo response and filter out high-frequency mechanical jitter. This feedforward control architecture effectively isolates the wing's aerodynamic angle of attack from the fuselage's pitch attitude changes, achieving decoupled control of the wing's aerodynamic angle of attack and the fuselage's pitch angle.

[0108] In this embodiment, the aerodynamic angle of attack of the target wing, previously obtained as a GOE 384 lifting wing, is... The optimal angle is 10°, which is the preset installation deviation angle for the lifting wing. Installation angle control gain coefficient At a flight speed of 10 m / s and a pitch angle of [missing information], Under the condition of -20°, substituting into the formula, we can obtain the deflection angle of the lifting wing relative to the fuselage. The drive servo motor 13 drives the lifting wing body 1 to deflect by 20 degrees, which is equivalent to the airframe deflecting, thus enabling the robot to maintain a stable aerodynamic angle of attack at the target wing. In the current state.

[0109] The aircraft pitch angle is the angle between the aircraft's longitudinal axis and the horizontal plane, used to characterize the overall pitch attitude of the aircraft, and is acquired in real time by the IMU in the sensing module. The lifting wing has a preset installation deviation angle. The initial mechanical assembly angle between the chord line of the lifting wing body 1 and the longitudinal axis of the fuselage is a fixed reference angle at the structural level. The preset installation deviation angle for the lifting wing is... The preset angle offset to match the target aerodynamic performance is a fixed parameter for the control algorithm. The deflection angle of the lifting wing relative to the airframe. The angle of deflection of the lifting wing relative to the longitudinal axis of the fuselage is driven by the servo motor 13. The aerodynamic angle of attack of the target wing is the aerodynamic angle between the chord line of the main body of the lifting wing 1 and the direction of the incoming flow, and is a core aerodynamic parameter that determines the lift-to-drag ratio performance of the wing.

[0110] Furthermore, this embodiment also included field tests of flight performance:

[0111] The robot's flight performance was tested in a suburban area of ​​a city. The test environment was cloudy, with an ambient temperature of 27°C and a ground wind speed of 1-2 m / s. Forward flight tests in cruise configuration were conducted at an altitude of 15-20 m, a range that avoids ground effect while facilitating visual observation. The robot was evaluated at three target cruise speeds: 8 m / s, 10 m / s, and 12 m / s, with corresponding pitch angles of -15°, -20°, and -25°, respectively. During the tests, a CUAV V5nano controller integrating a NEO3 GPS module and a power management unit (PMU) was used to collect data on horizontal speed, flight altitude, voltage, current, and pitch angle. The flight path during the tests is shown below. Figure 13 As shown.

[0112] To ensure data reliability, the test transitioned to the forward flight phase after hovering at an altitude of approximately 20 m, accelerating to the target cruise speed. Abnormal data was filtered using the following exclusion criteria: (1) significant coupled oscillations between pitch attitude and flight altitude; (2) a deviation of the maintained speed from the set value exceeding ±0.2 m / s; (3) a steady-state flight phase duration of less than 8 s; and (4) significant deviations between telemetry data (voltage, current, pitch angle, altitude) and the steady-state mean. Three sets of valid data were retained for performance analysis after screening.

[0113] Figure 14 Flight data of the robot alternating between hovering and constant-speed cruising at 12 m / s are presented. The figure uses blue, orange, and green lines to represent battery output current, flight speed, and flight altitude, respectively. Test results show that the average current during hovering is 18.52 A, the battery voltage is 24.56 V, and the corresponding flight power is 456.52 W; during constant-speed cruising at 12 m / s, the average current is 11.38 A, and the corresponding flight power is 279.49 W, a reduction of approximately 38.78%, verifying the significant effect of wing lift on reducing rotor output power.

[0114] The experimental verification of optimal flight conditions (speed: 10 m / s; airframe pitch angle: -20°; wing aerodynamic angle of attack: 10°) is as follows: Figure 15 As shown in the figure, the blue line represents the body pitch angle (°), the orange line represents the robot's flight speed (m / s), the yellow line represents the robot's flight altitude (m), the purple line represents the battery output current (A), and the green line represents the wing's aerodynamic angle of attack (°). Figure 15Figures (a), (b), and (c) illustrate the time histories of pitch attitude, forward velocity, flight altitude, voltage, and current during the transition from hovering to stable cruise. Due to strict payload weight limitations, no telemetry instrument was integrated to directly measure the propeller speed (RPM); therefore, the assessment of aerodynamic efficiency relied on the total power consumption derived from the voltage and current measurements summarized in Table 2. Analysis of this telemetry data revealed key characteristics related to flight stability and aerodynamic efficiency. Specifically, during the transition from hovering to forward cruise, the robot successfully maintained a constant altitude of approximately 20 meters. This performance confirms the robust stability of the invention under the dynamic coupling effects caused by rapidly changing pitch angles and velocities. Furthermore, a significant correlation was observed between fuselage attitude and power consumption: with increasing pitch angle... From the 0° hovering position to the -20° cruise configuration, current consumption decreased significantly from the baseline of 17.28A to 9.79A, indicating a 43.34% reduction in power during cruise compared to the hovering phase. This substantial reduction in flight power validates the wing's effective lift generation capability at the optimal pitch angle. Figure 15 (a), (b), and (c) show the results of the three experiments, respectively.

[0115] Table 3 shows a comparison of power consumption at different flight speeds, providing quantitative verification of the aerodynamic performance predicted by numerical simulation. A significant monotonic decrease in power demand was observed when the robot transitioned from hovering to forward cruise. Specifically, the average power consumption decreased from approximately 399W in hovering to 227W at 10 m / s. This significant decrease confirms that 10 m / s is the optimal aerodynamic operating point for the lifting wing to generate maximum efficiency. This trend demonstrates the unique advantage of the variable angle of attack mechanism 4: unlike fixed-wing quadrotors where lift degradation occurs at high speeds due to negative pitch angles, the proposed mechanism actively decouples fuselage attitude from wing aerodynamic angle of attack. This allows the wing to maintain high lift generation over a wider speed range (8-12 m / s), significantly reducing the burden on the propulsion system and validating the effectiveness of the proposed configuration in extending flight endurance.

[0116] Table 2. Flight Function Test Parameters:

[0117]

[0118] Table 3. Comparison of power consumption at different flight speeds:

[0119]

[0120] In summary, this invention is achieved through the following technical means:

[0121] (1) At the structural level, an integrated configuration of "X-shaped quadrotor + variable angle lifting wing + detachable variable diameter wheel" is proposed. The lifting wing is integrated into the fuselage, and the flight control and battery are integrated inside to optimize space utilization and reduce weight. For cruise speeds of 8~15m / s, the GOE 384 high-lift airfoil (chord length 510mm, span 400mm, projected area 0.204m²) is selected, and a variable angle of attack mechanism 4 driven by drive servo 13 is set up so that the aerodynamic angle of attack of the wing can be actively adjusted within the range of -30°~30° to adapt to the aerodynamic requirements of different flight modes.

[0122] (2) At the control level, a feedforward-based pitch-angle-attack decoupling control law is proposed. This is achieved through the formula... Real-time calculation of the deflection angle of the lifting wing relative to the airframe The deflection angle of the lifting wing relative to the fuselage is independently adjusted by the secondary controller. This completely decouples the effective angle of attack of the wing from the pitch attitude of the fuselage, avoiding interference of fuselage attitude changes with the aerodynamic efficiency of the wing.

[0123] (3) At the verification level, field flight tests show that under the optimal cruise conditions (speed 10m / s, airframe pitch angle -20°, wing effective angle of attack 10°), the flight power is reduced by 43.34% compared to hovering; and the effective angle of attack is maintained in the range of 4°~12° within a wide speed range of 8~12m / s, with a lift-to-drag ratio greater than 4.0, which verifies the significant effect of the present invention in terms of improving range and full envelope aerodynamic efficiency.

[0124] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A long-endurance amphibious robot based on a variable-angle lifting wing, characterized in that: The system includes a lifting wing and a fuselage; the lifting wing includes a lifting wing body (1) and two wing side plates (2) respectively disposed on both sides of the lifting wing body (1), each wing side plate (2) having two through holes extending along the wingspan direction; the fuselage includes two load-bearing carbon tubes (12), two variable angle of attack mechanisms (4), a quadcopter power system, and two variable diameter wheel mechanisms (5); the two load-bearing carbon tubes (12) are arranged parallel to each other along the wingspan direction inside the lifting wing body (1), and the ends of the two load-bearing carbon tubes (12) on the same side correspond to the positions of the two through holes on the corresponding side wing side plate (2); the two variable angle of attack mechanisms (4) are respectively disposed at both ends of the load-bearing carbon tubes (12), and each The main body of the variable angle of attack mechanism (4) is located on the outside of the corresponding wing side plate (2); each variable angle of attack mechanism (4) passes through the corresponding side insertion hole and is fixedly connected to the same side end of the two load-bearing carbon tubes (12), and is connected to the corresponding wing side plate (2) for driving the lifting wing body (1) to rotate around the axis of the two load-bearing carbon tubes (12) to adjust the aerodynamic angle of attack of the lifting wing; the two variable diameter wheel mechanisms (5) are respectively set below the variable angle of attack mechanism (4) on the corresponding side, and each variable diameter wheel mechanism (5) is provided with a walking wheel with adjustable wheel diameter, which is used to enable the robot to travel quickly on flat ground, overcome obstacles in rugged or narrow terrain, and shrink the wheel diameter to reduce aerodynamic drag when flying in the air.

2. The long-endurance amphibious robot according to claim 1, characterized in that: The lifting wing also includes multiple wing support rods (6); the lifting wing body (1) is formed by an upper arc plate and a lower flat plate, and two wing side plates (2) are fixedly installed on both sides of the lifting wing body (1), and the lifting wing body (1) and the two wing side plates (2) together form an internal cavity; multiple wing support rods (6) are arranged parallel to each other in the internal cavity along the wingspan direction and the two ends of each wing support rod (6) are fixedly connected to the wing side plates (2) on both sides.

3. The long-endurance amphibious robot according to claim 1, characterized in that: Each of the variable angle of attack mechanisms (4) includes a drive servo (13), an aluminum alloy connector (14), and a servo disc (15); the aluminum alloy connector (14) is provided with a transverse base and two plug-in arms, the two plug-in arms protruding from the transverse base and facing one side of the wing side plate (2), the two plug-in arms passing through the plug-in through holes on the corresponding sides and being fixedly sleeved to the ends of two load-bearing carbon tubes (12); the transverse base is located on the outside of the wing side plate (2), and the two ends of the transverse base are fixedly connected to the quadcopter power system; each variable diameter wheel mechanism (5) It can be detachably installed on the lower part of the transverse base of the corresponding side aluminum alloy connector (14); the drive servo (13) is fixed in the middle of the transverse base, and the output shaft of the drive servo (13) is arranged along the wingspan direction; the inner ring of the servo disk (15) is fixedly connected to the output shaft of the drive servo (13), and the outer ring of the servo disk (15) is fixedly connected to the wing side plate (2) on the same side; the drive servo (13) drives the wing side plate (2) and the lifting wing body (1) to rotate synchronously around the axis of the load-bearing carbon tube (12) through the servo disk (15).

4. The long-endurance amphibious robot according to claim 3, characterized in that: Each of the aforementioned variable diameter wheel mechanisms (5) includes a support leg (16), an auxiliary wheel (19), a walking drive motor (17), a hollow shaft (18), a wireless power supply transmitter coil (20), a wireless power supply receiver coil (21), a variable diameter servo motor (22), a central hub (23), a transmission servo disc (24), a connecting turntable (25), multiple sets of umbrella wheels (26), multiple connecting rods (27), and a rubber outer ring; The upper end of the support leg (16) is detachably installed on the lower part of the transverse base of the corresponding side aluminum alloy connector (14). The support leg (16) is provided with an auxiliary wheel (19) mounting arm extending along one side perpendicular to the wingspan direction. The end of the auxiliary wheel (19) mounting arm is rotatably mounted with an auxiliary wheel (19). The walking drive motor (17) is fixedly installed on the inner side of the support leg (16), and the output shaft of the walking drive motor (17) is arranged outward along the wingspan direction; the lower part of the support leg (16) is provided with a through hole that runs through the wingspan direction, and the hollow shaft (18) is coaxially inserted into the through hole. One end of the hollow shaft (18) is connected to the output shaft of the walking drive motor (17) for transmission, and the other end of the hollow shaft (18) extends out to the outside of the support leg (16) and is coaxially fixedly connected to the center hub (23); The wireless power supply transmitter coil (20) is fixedly installed around the mounting through hole on the outside of the support leg (16), and the wireless power supply receiver coil (21) is coaxially embedded in the internal cavity of the hollow shaft (18); the variable diameter servo motor (22) is fixedly installed at the internal center of the central hub (23), and the wire harness of the variable diameter servo motor (22) is arranged inside the hollow shaft (18). One end of the wire harness is electrically connected to the wireless power supply receiver coil (21), and the other end extends into the central hub (23) and is electrically connected to the variable diameter servo motor (22); The central hub (23) is evenly provided with multiple radially extending guide grooves in the circumference. The radial inner end of each set of umbrella wheels (26) is correspondingly embedded in a guide groove, and can slide radially back and forth along the guide groove. The outer surface of all umbrella wheels (26) is covered with a rubber outer ring. The transmission rudder disk (24) and the connecting turntable (25) are arranged coaxially on the outside of the central hub (23) in sequence. The inner ring of the transmission rudder disk (24) is fixedly connected to the output shaft of the variable diameter servo (22), and the outer ring of the transmission rudder disk (24) is fixedly connected to the connecting turntable (25). Multiple connecting rods (27) are evenly hinged around the circumference of the connecting turntable (25). The outer end of each connecting rod (27) is correspondingly hinged to the radial inner end of a set of umbrella wheels (26). The variable diameter servo (22) drives the connecting turntable (25) to rotate circumferentially through the transmission rudder disk (24), and drives each set of umbrella wheels (26) to synchronously extend and retract radially along the guide groove through the connecting rods (27), thereby realizing the switching of the wheel diameter between the minimum and maximum states.

5. The long-endurance amphibious robot according to claim 3, characterized in that: The quadcopter power system includes four rotor arms (3) and rotor power units respectively installed on the outer ends of each rotor arm (3); the two rotor arms (3) located on the same side of the fuselage extend obliquely toward the front and rear sides of the fuselage respectively, and each rotor arm (3) is arranged at an angle to the longitudinal axis of the fuselage in the top view direction, and the four rotor arms (3) form an X-shaped symmetrical layout; the inner end of each rotor arm (3) is fixed to the transverse base end of the corresponding side aluminum alloy connector (14).

6. The long-endurance amphibious robot according to claim 5, characterized in that: The rotor power unit includes a motor mount (9), a drive motor (8), and a propeller (7); the motor mount (9) is fixedly installed at the outer end of each rotor arm (3); the drive motor (8) is fixed on the motor mount (9), the output shaft of the drive motor (8) is arranged vertically, and the propeller (7) is coaxially fixed on the output shaft of the drive motor (8).

7. A hierarchical control system for a long-endurance amphibious robot according to any one of claims 1-6, characterized in that, include: The motion control module includes a main controller, a secondary controller, a flight motion execution unit, and a ground motion execution unit; the flight motion execution unit includes a drive motor (8) and a drive servo motor (13); the ground motion execution unit includes a walking drive motor (17) and a variable diameter servo motor (22); the remote control link includes a data transmission device, a ground station, a first remote controller, and a second remote controller; The main controller is connected to each drive motor (8) for adjusting the speed of each drive motor (8); the secondary controller is connected to each drive servo motor (13) for adjusting the output angle of the drive servo motor (13); the secondary controller is also connected to each walking drive motor (17) for coordinating the control of the speed of the walking drive motors (17) on both sides. The data transmission device is connected to the ground station to transmit data to the ground station, which is used for motion mode planning and operation status monitoring. The first remote controller is connected to the main controller and the secondary controller respectively. After the operator observes the information of the ground station, the operator sends motion control commands to the main controller and the secondary controller through the first remote controller. The second remote controller is connected to the variable diameter servo (22) to directly control the variable diameter servo (22) independently.

8. A method for decoupling aerodynamic angle-of-attack feedforward control of a wing in the hierarchical control system of claim 7, characterized in that, Includes the following steps: S1. Real-time acquisition of aircraft pitch angle Substituting the preset aerodynamic angle-of-attack feedforward model, the deflection angle of the lifting wing relative to the fuselage is calculated. ; S2, based on the deflection angle Generate servo control signals to control the drive servos (13) on both sides to synchronously drive the lifting wings to deflect relative to the fuselage. The angle is adjusted to counteract the interference of changes in the aircraft's pitch attitude on the wing's aerodynamic angle of attack.

9. The wing aerodynamic angle of attack feedforward decoupling control method according to claim 8, characterized in that: The aerodynamic angle-of-attack feedforward model is set according to the following formula: ； In the formula, The deflection angle of the lifting wing relative to the fuselage; The target wing's aerodynamic angle of attack; Preset the installation deviation angle for the lifting wing; The gain coefficient is controlled by the installation angle. The pitch angle of the aircraft.

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