Wing type biological mixing flapping wing air vehicle with deformable wings

Abstract

The invention provides a wing type biological hybrid flapping wing aircraft with deformable wings. The wing type biological hybrid flapping wing aircraft comprises a flapping mechanism, a wing deformation mechanism, bird feather type wings, an aircraft body, an empennage deformation mechanism and a bird feather type empennage, the flapping mechanism and the empennage deformation mechanism are mounted on the fuselage; the flapping mechanism drives the wing deformation mechanism to do wing flapping motion; the bird feather type wings are arranged on the wing deformation mechanism; the empennage deformation mechanism comprises an empennage joint and a plurality of steering engines, the steering engines drive the empennage joint to do four-degree-of-freedom motion, and the bird feather type empennage is installed on the empennage joint. The multi-degree-of-freedom cooperative connecting rod transmission mechanism is adopted, high-fidelity reproduction of bird flapping wing motion is efficiently achieved, and independent and accurate regulation and control of the torsion angle, the torsion rate and the torsion direction of the empennage are achieved based on hierarchical steering engine control and the decoupling characteristic of the double-layer motion frame.

Description

Technical Field

[0001] The present invention relates to the field of flapping-wing aircraft, and more particularly, to a feather-type biohybrid deformable-wing flapping-wing aircraft. Background Art

[0002] Birds in nature exhibit powerful flight maneuverability and environmental adaptability through flapping-wing flight. Inspired by the flight of birds, on the one hand, flapping-wing aircraft generate lift by mimicking the periodic flapping of bird wings, and can perfectly blend into the environment in terms of shape and motion mode, with far better concealment than rotors and fixed wings; on the other hand, they mimic the flapping-gliding mode of birds to significantly reduce energy consumption during flight. The above characteristics make flapping-wing aircraft have great application prospects in many fields such as military, civilian, and scientific research.

[0003] The existing flapping-wing aircraft perform far less well in terms of maneuverability than real birds. Specifically, birds can very efficiently achieve rapid turning while ensuring flight efficiency through the multi-degree-of-freedom torsion and in-plane folding and unfolding deformation of their wings and tail wings during flight. In contrast, the existing flapping-wing aircraft still face challenges in deformable wings.

[0004] Certain achievements have been made in the research on deformable wings. For example, in the Chinese patent document with the publication number CN114735211A, a deformable flexible wing aircraft is provided, which controls the spatial swing of the sub-wings through a mechanical transmission mechanism. However, the integrated membrane wing structure of the existing flapping-wing aircraft will exhibit out-of-plane wrinkling deformation during the mechanical deformation process, resulting in a reduction in aerodynamic efficiency; on the other hand, there is still a lack of coupled deformation for the wing and tail wing structures of flapping-wing aircraft. Therefore, there is an urgent need for a deformable-wing flapping-wing aircraft that can reproduce the coordinated in-plane flat deformation of real bird wings and tail wings in terms of structural characteristics, so as to achieve a stable and flexible flight attitude of the flapping-wing aircraft during flight. Summary of the Invention

[0005] Aiming at the defects in the prior art, the purpose of the present invention is to provide a feather-type biohybrid deformable-wing flapping-wing aircraft.

[0006] A feather-type biohybrid deformable-wing flapping-wing aircraft according to the present invention includes: a flapping mechanism, a wing deformation mechanism, a bird feather-type wing, a fuselage, a tail wing deformation mechanism, and a bird feather-type tail wing;

[0007] The flapping mechanism and the tail wing deformation mechanism are installed on the fuselage;

[0008] The flapping mechanism includes a pair of meshing first rocker arms, second rocker arms, and a driving unit. The driving unit drives the first rocker arms and the second rocker arms to swing reciprocally. The first rocker arms and the second rocker arms are connected to the wing deformation mechanism to drive the wing deformation mechanism to perform flapping motion. The bird feather-like wings are installed on the wing deformation mechanism.

[0009] The tail wing deformation mechanism includes a tail wing joint and a plurality of servos. The plurality of servos drive the tail wing joint to perform four-degree-of-freedom motion. The bird feather-like tail wing is installed on the tail wing joint.

[0010] Preferably, the bird feather-like wings and the bird feather-like tail wings adopt discrete feather units. The discrete feather units adopt real bird feathers or discrete artificial feathers. The discrete feather units are arranged in an alternating overlapping manner, and the overlapping area of adjacent discrete feather units accounts for 30%-70% of the area of a single feather.

[0011] Preferably, the discrete feather units are fixed by being inserted into slots. The slots are made of carbon fiber tubes, with an inner diameter of 1.4-1.6 mm, a wall thickness of 0.2-0.3 mm, and the distance between adjacent slots is 1.2-1.8 times the diameter of the feather root.

[0012] Preferably, adjacent slots are connected by inelastic tendons to form a continuous constraint. The inelastic tendons are woven from Kevlar fibers, with a breaking strength ≥300 MPa and an elongation rate ≤2%.

[0013] Preferably, the wing deformation mechanism includes two sets of space parallelogram mechanisms with inner angle coupling. The wing deformation mechanism includes:

[0014] The wing root driving part: composed of the first parallelogram mechanism. The first parallelogram mechanism includes a third link, a fourth link, a fifth link, and a sixth link.

[0015] The wing middle linkage part: composed of the second parallelogram mechanism. The second parallelogram mechanism includes a first link, a second link, a third link, and a fourth link. The rod length ratio of the first link, the second link, the third link, and the fourth link is 1:0.82:1:0.82.

[0016] The wing tip follower part: composed of the first link.

[0017] The minimum inner angle change range of the two sets of parallelogram mechanisms is 10°-80°, corresponding to a wingspan contraction ratio of 50%-100%.

[0018] The sixth link is connected to the vertical slide rail through a slider, and the slider is connected to the first rocker arm and the second rocker arm.

[0019] Preferably, the first parallelogram mechanism and the second parallelogram are kinematically coupled through a fourth link, and the rate of change of the angle between the fourth link and the vertical slide rail is in the ratio of 1:0.6 - 0.8.

[0020] Preferably, the tail deformation mechanism includes an outer fixed frame, an inner moving frame, and a tail joint;

[0021] The outer fixed frame is rigidly connected to the fuselage;

[0022] The inner moving frame realizes a rolling motion through a first servo; the tail joint is connected to the inner moving frame and rolls with the inner moving frame;

[0023] The tail joint controls the wing surface deployment angle through a second servo and a third servo;

[0024] The tail joint controls the pitch and yaw motions respectively through a fourth servo and a fifth servo.

[0025] Preferably, the second servo and the third servo drive the tail joint through a push-pull wire wrapped in a polytetrafluoroethylene tube. The diameter of the wire ranges from 0.2 to 0.5 mm, and its pre-tightening force is 5 - 10 N.

[0026] Preferably, the flapping frequency of the flapping mechanism is ≥5 Hz.

[0027] Preferably, the fuselage uses a carbon fiber square tube as the main load-bearing structure. The wall thickness of the square tube is 5 - 7 mm, and the outer part is covered with an EPP shell with a thickness of 2 - 4 mm.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. Through the innovatively designed multi-degree-of-freedom collaborative link transmission mechanism, the present application efficiently realizes the high-fidelity reproduction of the flapping motion of birds. This mechanism adopts a composite configuration of a spatial link and a crank-link mechanism. Through the precisely designed rod proportion relationship and kinematic pair configuration, it accurately reproduces the bionic kinematic characteristics of the bird's wings, specifically the active folding of the wing surface during the upstroke phase and the passive extension of the wing surface during the downstroke phase. This motion mode can effectively reduce the negative work output during the upstroke phase and improve the work efficiency during the downstroke phase.

[0030] 2. Through the innovative double-layer motion framework structure combined with the hierarchical servo control technology, this application adopts a composite transmission mechanism of a push rod driving a metal wire in a polytetrafluoroethylene tube and a torque joint. While ensuring the efficient synchronous drive of the feathers, it successfully achieves the fully decoupled control of the four degrees of freedom of yaw, pitch, roll, and folding and unfolding of the tail wing, breaking through the technical bottlenecks such as low control accuracy and response hysteresis caused by the coupling of multiple degrees of freedom in traditional flapping-wing aircraft, and significantly improving the fine adjustment ability of the flight attitude.

[0031] 3. Through the multi-degree-of-freedom independent torsion control of the tail wing, this application significantly enhances the maneuverability of the aircraft. Compared with the tail wing movement of traditional flapping-wing aircraft, which is usually limited to a single degree of freedom or a fixed coupling mode and is difficult to dynamically adjust the torsion angle and action direction of the tail wing according to flight requirements, resulting in maneuvering response hysteresis and insufficient redundancy in flight trajectory adjustment. Based on the decoupling characteristics of hierarchical servo control and the double-layer motion framework, this application realizes the independent and precise control of the torsion angle, torsion rate, and torsion direction of the tail wing, and can generate aerodynamic moments in real time according to the flight attitude: generating instantaneous lateral moments through asymmetric torsion of the tail wing during high-speed turning to shorten the turning radius, adjusting the lift distribution by dynamic torsion of the tail wing during hovering or low-speed flight to improve attitude stability, and even completing complex three-dimensional maneuvering actions (such as roll avoidance, sudden stop and change of direction, etc.) through the synergistic effect of continuous torsion of the tail wing and flapping-wing motion.

[0032] 4. This application uses discrete natural bird feathers to construct the wing surface structures of the wings and tail wings, making the flapping-wing aircraft have stronger concealment in appearance; having special properties such as strong wind resistance, tear resistance, and self-repair due to the hierarchical self-locking of the feather microstructure in terms of material performance; and being able to achieve smooth changes in the wing surface during the dynamic deformation process, without the inevitable aerodynamic surface collapse problem in the membrane wing deformation structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Other features, objectives, and advantages of the present invention will become more apparent by reading the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0034] Figure 1 Schematic diagram of the winged biohybrid deformable-wing flapping-wing aircraft according to an embodiment of the present invention;

[0035] Figure 2 Model diagram of the drive gear set according to an embodiment of the present invention;

[0036] Figure 3 Schematic diagram of the passive folding and unfolding deformation structure of the wing according to an embodiment of the present invention;

[0037] Figure 4 Model diagram of the four-degree-of-freedom deformation mechanism of the tail wing according to an embodiment of the present invention;

[0038] Figure 5 This is a physical diagram of the deformable tail wing structure according to an embodiment of the present invention.

[0039] Explanation of the reference numerals in the drawings:

[0040] Specific embodiments

[0041] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all belong to the protection scope of the present invention.

[0042] The present invention provides a winged biohybrid deformable flapping wing aircraft, including: a flapping mechanism 1, a wing deformation mechanism 2, a bird feather-like wing 3, a fuselage 4, a tail wing deformation mechanism 5, and a bird feather-like tail wing 6.

[0043] The flapping mechanism 1 is composed of a brushless motor 11, a planetary gear set 14, a crank-link mechanism 15, and two mutually meshing first rocker arms 12 and second rocker arms 16. The brushless motor 11 drives the driving rod to rotate through the planetary gear set 14, and the driving rod drives two rocker arms to flap up and down while maintaining meshing through the crank-link mechanism 15, ensuring that the motion states of the left and right wings always remain symmetrical. The flapping frequency of the wings is changed only by adjusting the rotation speed of the brushless motor 11. The ends of the first rocker arm and the second rocker arm are rocker arm output shafts for connecting and driving the wing deformation mechanism.

[0044] In a specific embodiment, the flapping mechanism 1 is driven by a C20 1908 type KV2050 brushless motor 11, and is equipped with a center-through planetary gear set 14 to form a power core. The planetary gear set 14 adopts an annular layout design, including a sun gear (tooth number Z1), a planetary gear (tooth number Z2), a ring gear (tooth number Z3), and a spoke-type support frame, forming a 3:1 - 5:1 adjustable transmission ratio system. The driving rod is rigidly connected to the hollow output shaft of the gearbox, and drives two meshing first rocker arms 12 and second rocker arms 16 through the crank-link mechanism (15). The two rocker arms are symmetrically arranged on both sides of the base 13, and the distance between the axes of their rotation centers is equal to the pitch diameter of the gear meshing, ensuring that the phase difference between the left and right wings is constantly 180°. When the brushless motor 11 operates at a frequency of ≥5Hz, the rocker arm swing angle realizes a symmetrical flapping of ±30° - ±45°, and the maximum flapping angular velocity reaches 120° / s (corresponding to a wing tip linear velocity of 3.2m / s).

[0045] The peacock-style wing 3 is composed of 20 feathers of king pigeons, specifically including 9 primary feathers and 11 secondary feathers. The adjacent feathers overlap alternately, and all feathers are attached to the slots in the feather joints of the bone structure. The feather slots are made of 1.5 mm carbon fiber tubes, and the slots are interconnected by inelastic tendons, with one end connected to the body frame and the other end fixed to the wing deformation mechanism. Through this design, the movement range of the 20 feathers is restricted, and they always overlap consistently during the deformation process to form a complete surface, and underactuated control is achieved through a deformation mechanism with a single degree of freedom.

[0046] The wing deformation mechanism 2 is composed of seven spatial linkages excluding the rocker output shaft. One vertical linkage is connected to the rocker output shaft through a slider 28, and the remaining six linkages form two parallelogram mechanisms with inner angle coupling. One of the two adjacent linkages of the inner parallelogram extends and is fixed to the top of the vertical rod, and the other extends and is connected to the slider where the rocker is connected to the vertical linkage. The two parallelogram structures divide the entire wing into three parts: the wing tip, the wing middle, and the wing root, which are controlled by a single degree of freedom of the rocker. When the wing flaps upward, the minimum inner angle of the quadrilateral structure gradually increases from 10° in the fully extended state to 80°, and the effective wingspan length of the wing contracts to 50% of the maximum wingspan. When the wing flaps downward, the minimum inner angle of the quadrilateral structure gradually decreases from 80° to 10°, and the effective wingspan length of the wing extends to the maximum wingspan state.

[0047] In a specific implementation manner, the wing deformation mechanism 2 includes a double-layer motion system composed of seven spatial linkages (see Figure 3 ):

[0048] Wing root drive part: A first spatial parallelogram is formed by the third linkage 23, the fourth linkage 24, the fifth linkage 25, and the sixth linkage 26. The sixth linkage 26 is dynamically connected to the vertical slide rail 27 through a slider 28.

[0049] Wing middle linkage part: A second spatial parallelogram is formed by the first linkage 21, the second linkage 22, the third linkage 23, and the fourth linkage 24, and its rod length ratio is 1:0.82:1:0.82.

[0050] Wing tip follower part: The first linkage 21 forms a motion coupling with the wing middle linkage part.

[0051] When the rocker output shaft swings at ±30°, through the vertical displacement of the slider 28 (stroke range 15 mm, refer to Figure 3The up-and-down sliding of the middle ring drives the coordinated deformation of two sets of parallelograms (the first link 21, the second link 22, the third link 23, the fourth link 24, and the fifth link 25): during the upstroke phase, the minimum inner angle of the mechanism increases from 10° to 80°, and the wingspan contracts to 50% of the maximum value; during the downstroke phase, the inner angle resets to 10°, and the wingspan resumes 100%. The synchronous movement of 21 feathers is achieved through inelastic tendons during the deformation process, and the overlapping area of adjacent feathers remains 45%-55% to form a continuous wing surface.

[0052] The shell of the fuselage 4 is composed of six independent parts. Specifically, carbon fiber plates are cut and hollowed out by a laser marking machine and then glued and spliced together. The surface is smoothed with sandpaper and a hot iron to reduce aerodynamic friction resistance. The wing deformation mechanism and the tail wing deformation mechanism are respectively connected to the carbon fiber square tube at the center of the fuselage through a T-shaped connector and a universal joint. The square tube is surrounded by an EPP shell with a wall thickness of 6 mm. The fuselage hides the structural and electrical components in a soft shell.

[0053] The tail wing deformation mechanism 5 consists of a basic frame, tail wing joints 58, and five servos. The basic frame is divided into an outer fixed frame 51 and an inner moving frame 52. The two ends of the long axis of the inner moving frame 52 are respectively hinged to the outer fixed frame 51, so that the inner moving frame 52 can rotate around the long axis. A combination of push-pull metal wires wrapped in polytetrafluoroethylene tubes and torque joints is used to drive the feathers while keeping the mass close to the center of gravity. In the control part, the output end of the first servo 53 is connected to the inner moving frame 52 to directly control the roll movement of the entire tail wing structure, and the remaining four servos are fixed in the inner moving frame 52. Specifically, the second servo 54 and the third servo 55 are connected to the left and right sides of the root of the feather connection in the tail wing joint 58 through metal wires, and the folding and unfolding of the tail wing joint 58 are controlled by the stretching and push-pull movements of the metal wires on both sides; the fourth servo 56 is connected to the upper protruding joint at the joint connection in the same structure to control the pitch movement of the tail wing; the fifth servo 57 is connected to the left protruding joint at the joint connection to control the yaw movement of the tail wing.

[0054] In a specific implementation, the tail wing deformation mechanism 5 adopts a five-servo-driven four-degree-of-freedom architecture (see Figure 4 ):

[0055] Roll control: The first servo 53 (model MG90S) directly drives the inner frame 52 to rotate ±25° relative to the outer frame 51

[0056] Wing surface folding and unfolding: The second servo 54 and the third servo 55 pull the left and right sides of the tail wing joint 58 (the left and right sides of the fan-shaped tail) through 304 stainless steel wires with an inner diameter of 0.8 mm of PTFE tubes to achieve a linear adjustment of the wingspan of 60-120 mm, and to make the central angle of the fan-shaped tail larger / smaller.

[0057] Pitch control: The fourth servo 56 controls the tail wing joint (58) to pitch ±15° through a push-pull wire with a pre-tightening force of 8N. The fan-shaped tail wing joint is rotationally connected to the inner layer motion frame, allowing the tail wing joint to flap up and down along the center of the circle in a direction perpendicular to the fan shape.

[0058] Yaw control: The fan-shaped tail wing joint allows horizontal rotation at the center of the circle. The fifth servo 57 realizes a ±20° deflection of the tail wing through a double-strand stranded wire.

[0059] The tail wing joint 58 adopts a curved carbon fiber root structure (curvature radius R = 8mm). 12 pigeon tail feathers (601) are embedded in a 1.5mm inner diameter slot with an overlap ratio of 55%, and are evenly distributed at an interval of 1.8mm through Kevlar fiber tendons. The four-degree-of-freedom motion response time ≤ 80ms, and the angular resolution reaches 0.5°.

[0060] The bird feather type tail wing is composed of 12 pigeon tail feathers. The adjacent feathers overlap alternately, and the feather roots are embedded in the slots of the joint. The feather slots are made of 1.5mm carbon fiber tubes, and the slots are fixed on the curved root joint and connected to each other through inelastic tendons.

[0061] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0062] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A winged biohybrid deformable wing flapping aircraft, characterized in that Comprising: A flapping mechanism (1), a wing deformation mechanism (2), a bird feather-like wing (3), a fuselage (4), a tail wing deformation mechanism (5) and a bird feather-like tail wing (6); The flapping mechanism (1) and the tail wing deformation mechanism (5) are installed on the fuselage (4); The flapping mechanism (1) includes a pair of meshing first rocker arms (12), second rocker arms (16) and a driving unit, and the driving unit drives the first rocker arms (12) and the second rocker arms (16) to make reciprocating swings; the first rocker arms (12) and the second rocker arms (16) are connected to the wing deformation mechanism (2) to drive the wing deformation mechanism (2) to perform flapping wing motion; the bird feather-like wing (3) is installed on the wing deformation mechanism (2); The tail wing deformation mechanism (5) includes a tail wing joint (58) and a plurality of servos, and the plurality of servos drive the tail wing joint (58) to perform four-degree-of-freedom motion, and the bird feather-like tail wing (6) is installed on the tail wing joint (58).

2. The winged biohybrid deformable wing flapping aircraft according to claim 1, wherein The bird feather-like wing (3) and the bird feather-like tail wing (6) adopt discrete feather units, the discrete feather units adopt real bird feathers or discrete artificial feathers, the discrete feather units are arranged in an alternating overlapping manner, and the overlapping area of adjacent discrete feather units accounts for 30%-70% of the area of a single feather.

3. The feather-wing type biohybrid deformable wing flapping aircraft according to claim 2, characterized in that, The discrete feather units are fixedly embedded through slots, the slots are made of carbon fiber tubes, the inner diameter thereof is 1.4-1.6 mm, the wall thickness of the tube is 0.2-0.3 mm, and the distance between adjacent slots is 1.2-1.8 times the diameter of the feather root.

4. The winged biohybrid deformable flapping-wing aircraft according to claim 3, characterized in that Adjacent slots are connected by inelastic tendons to form continuous constraints; the inelastic tendons are woven from Kevlar fibers, and their breaking strength ≥ 300 MPa and elongation rate ≤ 2%.

5. The winged biohybrid deformable flapping-wing aircraft according to claim 1, characterized in that The wing deformation mechanism (2) includes two sets of space parallelogram mechanisms with inner angle coupling, and the wing deformation mechanism (2) includes: A wing root driving part: composed of a first parallelogram mechanism; the first parallelogram mechanism includes a third link (23), a fourth link (24), a fifth link (25) and a sixth link (26); A wing middle linkage part: composed of a second parallelogram mechanism; the second parallelogram mechanism includes a first link (21), a second link (22), a third link (23) and a fourth link (24); the rod length ratio of the first link (21), the second link (22), the third link (23) and the fourth link (24) is 1:0.82:1:0.82; A wing tip follower part: composed of the first link (21); The minimum inner angle change range of the two sets of parallelogram mechanisms is 10°-80°, and the corresponding wingspan contraction ratio is 50%-100%; The sixth link (26) is connected to the vertical slide rail (27) through a slider (28), and the slider (28) is connected to the first rocker arm (12) and the second rocker arm (16).

6. The winged biohybrid deformable flapping-wing aircraft according to claim 1, characterized in that, The first parallelogram mechanism and the second parallelogram are motion-coupled through the fourth link (2), and the angle change rate ratio of the fourth link (24) to the vertical slide rail (27) is 1:0.6-0.

8.

7. The flapping-wing aircraft with a wing-like biohybrid deformable wing according to claim 1, characterized in that, The fin deformation mechanism (5) includes an outer fixed frame (51), an inner moving frame (52) and a fin joint (58); The outer fixed frame (51) is rigidly connected to the fuselage (4); The inner moving frame (52) realizes a rolling motion through a first servo (53); the fin joint (58) is connected to the inner moving frame (52) and accompanies the rolling motion of the inner moving frame (52); The fin joint (58) controls the wing surface deployment angle through a second servo (54) and a third servo (55); The fin joint (58) controls the pitch and yaw motions respectively through a fourth servo (56) and a fifth servo (57).

8. The winged biohybrid deformable wing flapping aircraft according to claim 7, characterized in that The second servo (54) and the third servo (55) drive the fin joint (58) through a push-pull wire wrapped in a polytetrafluoroethylene tube. The diameter of the wire ranges from 0.2 to 0.5 mm, and its pre-tightening force is 5 to 10 N.

9. The winged biohybrid deformable wing flapping aircraft according to claim 1, characterized in that, The flapping frequency of the flapping mechanism (1) is ≥ 5 Hz.

10. The winged biohybrid deformable wing flapping aircraft according to claim 1, characterized in that, The fuselage (4) uses a carbon fiber square tube as the main load-bearing structure. The wall thickness of the square tube is 5 to 7 mm, and the outside is covered with an EPP shell with a thickness of 2 to 4 mm.

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