Bionic flapping wing aircraft

Abstract

The invention discloses a bionic ornithopter. The bionic ornithopter comprises a main frame, the power source is arranged on the main rack; the power transmission mechanism is connected with the power source and used for converting the rotary motion of the power source into low-rotating-speed high-torque output; the reciprocating motion mechanism is connected with the power transmission mechanism and converts the low-rotating-speed high-torque output into reciprocating flapping motion of wings; the attitude control mechanism comprises a plurality of steering engines, the steering engines independently control rolling, pitching and yawing actions of the aircraft respectively, the lift force direction is adjusted by changing the attack angle of wings, the gravity center position of the aircraft is adjusted in a synchronous linkage mode, and cooperative control over the flight attitude is achieved; and the wings are connected to the reciprocating motion mechanism and generate lift force through reciprocating flapping. The beneficial effects of the invention are that the structure is simple and reliable, and the modular design reduces the assembly difficulty; anti-interference performance is high, control is flexible, and light weight and durability are achieved; the carbon fiber is combined with the PE film, and the service life is not less than 500 hours.

Description

Technical Field

[0001] The invention relates to the technical field of flapping-wing aircraft, and in particular to a bionic flapping-wing aircraft. Background Art

[0002] Since the concept of flapping-wing aircraft was proposed, due to its potential broad application prospects in both military and civilian fields, micro flapping-wing aircraft has become a hot research and development hotspot in the world's advanced countries. The development of this type of aircraft mainly includes two aspects: insect-like flapping-wing aircraft and bird-like flapping-wing aircraft. Compared with bird-like flapping-wing aircraft, insect-like flapping-wing aircraft is smaller in size, lighter in weight, more maneuverable, and can achieve hovering flight. It has better research and development advantages in complex terrain observation, military reconnaissance and other fields. Summary of the invention

[0003] The main technical problem solved by the present invention is to provide a bionic flapping-wing aircraft to solve one or more of the above-mentioned prior art problems.

[0004] In order to solve the above technical problems, a technical solution adopted by the present invention is: a bionic flapping-wing aircraft, the innovation of which is: comprising

[0005] Main frame;

[0006] A power source is arranged on the main frame;

[0007] A power transmission mechanism, connected to the power source, for converting the rotational motion of the power source into a low-speed high-torque output;

[0008] A reciprocating motion mechanism, connected to the power transmission mechanism, converting the low speed high torque output into a reciprocating flapping motion of the wings;

[0009] The attitude control mechanism includes a plurality of steering gears, which independently control the roll, pitch and yaw movements of the aircraft, adjust the lift direction by changing the angle of attack of the wings, and synchronously adjust the center of gravity position of the aircraft to achieve coordinated control of the flight attitude;

[0010] Wings, connected to the reciprocating mechanism, generate lift by reciprocating flapping;

[0011] A power supply is used to supply power to the power source and the steering gear.

[0012] In some embodiments, the power transmission mechanism includes a reduction gear set connected to the reciprocating mechanism via a crankshaft.

[0013] In some embodiments, the reciprocating motion mechanism includes a sliding gear, symmetrically arranged swinging gears, a connecting rod, a crankshaft, symmetrically arranged pin shafts, and a fixed shaft. The sliding gear is connected to the crankshaft through the connecting rod. The fixed shaft horizontally penetrates the sliding gear in the front-rear direction of the aircraft and is fixed on the main frame. The rotational motion of the crankshaft is converted into the linear reciprocating motion of the sliding gear. The swinging gears are installed on both sides of the main frame through the pin shafts. The racks on both sides of the sliding gear engage to drive the rotational motion of the swinging gears, thereby driving the wings to flap.

[0014] In some embodiments, the attitude control mechanism includes a roll servo, a pitch servo, a yaw servo, a cross universal joint, a base, and a swinging frame. The axes of the output shafts of the roll servo and the pitch servo are perpendicular to each other and intersect. The pitch servo is connected to the base through the cross universal joint. The yaw servo drives the swinging frame to rotate to adjust the angle of attack difference between the two wings.

[0015] In some embodiments, symmetrically arranged universal rods are provided between the main frame and the swinging frame. The geometric layout of the universal rods satisfies that both the upper and lower ends of the universal rods are spherical. The upper end is connected to the main frame to form a ball universal joint and is located directly below the pin shaft, that is, the spherical center point of the upper end is located on the extension axis of the pin shaft. The lower end is connected to the swinging frame to form a ball universal joint in the same way. The distance between the centers of the upper spherical balls of the two side universal rods is equal to the distance between the centers of the lower spherical balls, and the line connecting the centers of the upper spherical balls is perpendicular to the axis of the output shaft of the roll servo and intersects.

[0016] In some embodiments, the wings include a flexible film and a support skeleton. One end of the support skeleton is fixed to the swinging gear, and the root of the flexible film is connected to the universal rod. The tension of the film is adjusted by the swinging of the universal rod to change the angle of attack.

[0017] In some embodiments, the power supply is fixed below the front and rear bases at the bottom of the aircraft and moves synchronously with the movement of the attitude control mechanism to adjust the center of gravity position.

[0018] In some embodiments, the maximum yaw rotation angle of the attitude control mechanism is ±30°.

[0019] In some embodiments, the axis of the output shaft of the roll servo and the axis of the output shaft of the pitch servo are perpendicular to each other and intersect at point A, and the center of the cross shaft of the cross universal joint is point B. Then the straight line AB from point A to point B is perpendicular to the axis of the output shaft of the pitch servo.

[0020] In some embodiments, the spherical center points at the upper end of the universal rod are point C and point D respectively, and the spherical center points at the lower end are point E and point F respectively; the linear distance CD from point C to point D is equal to the linear distance EF from point E to point F (CD = EF), and the linear distance CE from point C to point E is equal to the linear distance DF from point D to point F (CE = DF). At this time, AB = CE = DF. CD is perpendicular to the axis of the output shaft of the roll servo and intersects at point H, that is, the straight line AH from point A to point H is the perpendicular bisector of CD; the swing frame is installed on the output shaft of the yaw servo, and the vertical distances from the spherical center at the lower end to the output shaft of the yaw servo are equal. That is, the axis of the output shaft of the yaw servo perpendicularly bisects EF at point K. At this time, AH = BK.

[0021] The beneficial effects of the present invention are as follows: The technical solution of the present invention is simple and reliable, and the manufacturing cost is low: the modular design reduces the assembly difficulty; it has strong anti-interference ability and flexible control: the dual-effect control mechanism (lift + center of gravity) adapts to complex environments; it has light weight and durability: the combination of carbon fiber and PE film, with a service life ≥ 500 hours. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, where:

[0023] Figure 1 is the structural schematic diagram a of a bionic flapping-wing aircraft of the present invention.

[0024] Figure 2 is the structural schematic diagram b of a bionic flapping-wing aircraft of the present invention.

[0025] Figure 3 is the structural schematic diagram c of a bionic flapping-wing aircraft of the present invention.

[0026] Figure 4 、 Figure 5 and Figure 6 are the position schematic diagrams of points A, B, C, D, E, F and K of a bionic flapping-wing aircraft of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0028] Such asFigures 1 to 3 As shown in the figure, the embodiments of the present invention include:

[0029] 1. Overall structure

[0030] This bionic flapping-wing aircraft includes the following core components and connection methods:

[0031] Main frame 100: Serves as the installation base for all components.

[0032] Power source 200 (motor): The motor drives the gear set to perform a decelerating rotational motion. The brushless DC motor is fixed to the front end of the main frame 100 by bolts, and the output shaft is connected to the reduction gear set.

[0033] Power transmission mechanism 300: The reduction mechanism is driven by the motor to drive the gear set to perform a decelerating rotational motion. Its function is to reduce the speed and increase the torque. The first-stage helical gear (module 0.5, number of teeth 8) meshes with the second-stage spur gear (module 0.5, number of teeth 8 / 24), the second-stage double spur gear meshes with the third-stage double spur gear (module 0.5, number of teeth 8 / 24), and the third-stage double spur gear meshes with the fourth-stage spur gear (module 0.5, number of teeth 27). The reduction ratio is 1:30, and the output shaft is connected to the crankshaft 404 through a keyway.

[0034] Reciprocating motion mechanism 400: One end of the connecting rod 403 is connected to the crankshaft 404, and the other end is connected to the sliding gear 401. The fixed shaft is horizontally fixed on the main frame 100 in the front-rear direction of the aircraft and passes through the sliding gear 401. The sliding gear 401 performs a linear reciprocating motion (stroke ±9 mm) along the fixed shaft (diameter 1 mm). The racks on both sides of it mesh with the symmetrically arranged swinging gears 402 to drive the wings 600 to flap. The swinging gears 402 are installed on both sides of the main frame 100 through the pin shafts 405 to drive the wings 600 to flap.

[0035] Attitude control mechanism 500: It consists of 3 servos, adapter sleeves, universal forks, cross shafts, front bases, 2 universal rods 5041, swinging frames 506, etc. The roll servo 501 is fixed to the rear end of the bottom of the main frame 100. The axis of the output shaft of the roll servo 501 is vertically intersected with the axis of the output shaft of the pitch servo 502 at point A. The pitch servo 502 is installed on the output shaft of the roll servo 501 through an adapter sleeve and is connected to the base 505 through a universal joint 504. As Figure 6 shown, the center of the cross shaft of the universal joint 504 is point B. The straight line AB from point A to point B is perpendicular to the axis of the output shaft of the pitch servo 502. The yaw servo 503 drives the swinging frame 506 to rotate. The swinging frame 506 is installed on the output shaft of the yaw servo 503 and the vertical distance from the spherical center to the output shaft of the yaw servo 503 is equal.

[0036] The universal rod 5041 is symmetrically arranged between the main frame 100 and the swing frame 506. Both the upper and lower ends are spherical. The upper end is connected to the main frame 100 to form a ball joint and is located directly below the pin shaft 405 (i.e., the center point of the sphere is on the extension axis of the pin shaft 405), and the lower end is connected to the swing frame 506 to also form a ball joint.

[0037] Wings 600: Composed of a film and thin carbon fiber rods; T700 carbon fiber rods (diameter 1 mm) are inserted outside the swing gear 402. The root of the film wraps around the universal rod 5041 and leaves a deformation allowance so that the film can be tightened or relaxed when the universal rod 5041 moves.

[0038] Power source (battery): The battery is fixed on the lower sides of the rear base and the front base. The lithium polymer battery is fixed by nylon cable ties, and the center of gravity height is 35 mm.

[0039] 2. Working principle and advantages of the power transmission mechanism 300

[0040] The working principle of the power transmission mechanism 300 is as follows: The motor drives the reduction gear set, reducing the rotational speed from 3000 RPM to 600 RPM and increasing the torque from 0.5 N·m to 2.5 N·m; the rotation of the crankshaft 404 causes the connecting rod 403 to pull or push the sliding gear 401 to perform a linear reciprocating motion along the axis of the fixed shaft, with a stroke of ±15 mm. The swing gear 402 is installed on both sides of the main frame 100 through the pin shaft 405, driving the wings 600 to flap at a frequency of 5 Hz.

[0041] The advantages of the power transmission mechanism 300 are as follows: Simple and reliable structure, low manufacturing cost: The gear set adopts a standardized design, with low processing cost; Strong anti-interference ability: The meshing of helical gears reduces vibration and improves stability.

[0042] 3. Working principle and advantages of the reciprocating motion mechanism 400

[0043] The working principle of the reciprocating motion mechanism 400 is as follows: The linear reciprocating motion of the sliding gear 401 drives the swing gear 402 to perform a reciprocating rotational motion, which is ultimately converted into the front and back flapping of the wings 600; when the crankshaft 404 rotates one week, the sliding gear 401 completes one round trip motion, and the swing gear 402 symmetrically rotates ±30° through the pin shaft 405, driving the wings 600 to complete one complete flap.

[0044] The advantages of the reciprocating motion mechanism 400 are as follows: Symmetrical design: The two swing gears 402 move synchronously and in opposite directions, canceling out lateral vibration; Compactness: The sliding gear 401 and the fixed shaft are integrally designed, saving space.

[0045] 4. Working principle and advantages of the attitude control mechanism 500

[0046] The working principle of the attitude control mechanism 500 is as follows: Roll control: When the output shaft of the roll servo 501 rotates, it drives the pitch servo 502 and the universal fork to rotate together. The universal rod 5041 swings left / right, tightens one side of the film and relaxes the other side. When the right wing 600 flaps, the angle of attack increases, and the left wing 600 is the opposite. At the same time, the battery offsets (±10 mm) with the base 505, and the center of gravity and lift work together to achieve roll.

[0047] Pitch control: When the output shaft of the pitch servo 502 rotates, it drives the universal fork to rotate. The universal rod 5041 swings forward / backward. When the wing 600 flaps forward, the angle of attack gradually decreases, and when it flaps backward, the angle of attack gradually increases. The battery moves forward / backward synchronously (±8 mm) to enhance pitch stability.

[0048] Yaw control: The yaw servo 503 drives the swing frame 506 to rotate ±30°. The vertical distance from the spherical center at the lower end of the swing frame 506 to the output shaft of the yaw servo 503 is equal. The axis of the output shaft of the yaw servo vertically bisects EF at point K, and the two universal rods 5041 swing in opposite directions to form a lift difference.

[0049] Geometric constraints: The distance between the upper spherical centers CD = the distance between the lower spherical centers EF = 50 mm; CE = DF = 60 mm, and AB = CE = DF; CD is perpendicular to the axis of the output shaft of the roll servo 501 and intersects at point H. AH is the perpendicular bisector of CD, and AH = BK.

[0050] The advantages of the attitude control mechanism 500 are as follows: Flexible control: The three servos are independently controlled, and the response time < 100 ms; The center of gravity linkage enhances stability: The attitude adjustment and the center of gravity offset work together, and the wind resistance ability is improved.

[0051] 5. Structure and Material Technology of the Wing 600

[0052] Composition and technology: Support skeleton: The T700 carbon fiber rod adopts the hot pressing forming process (cured at 180 °C, pressure 10 MPa), and the tensile strength ≥ 3.5 GPa; Film: The film (thickness 0.1 mm) is coated with a UV-cured coating on the surface. Weather resistance index: UV resistance level 5 (ASTM G154), tear strength ≥ 85 N / cm.

[0053] The film at the upper end of the wing 600 is sleeved on the thick carbon fiber rod, and the root is bonded to the universal rod 5041 by the hot pressing process, leaving a 5 mm deformation margin to ensure the flexibility of the angle of attack adjustment.

[0054] 6. Control Algorithm and Sensor Feedback

[0055] Control Logic: The PID algorithm (Kp = 0.8, Ki = 0.05, Kd = 0.12) is adopted. The attitude angle data (accuracy ±0.1°) is collected in real time through the MPU6050 gyroscope, and hover control is achieved by combining with the BMP280 barometer (resolution 0.1m); Dynamic Adjustment: The servo angle and motor speed are automatically adjusted according to the flight state, and the hover accuracy is ±0.3m (±0.2m in a windless environment).

[0056] 7. Experimental Data and Performance Verification

[0057] Hover Accuracy: Drift < 0.5m under level 3 wind speed, < 0.2m in a windless environment;

[0058] Maximum Load: Total weight 500g (including additional load 100g), endurance time 15 minutes;

[0059] Wind Resistance: Can resist level 5 gusts (10.7m / s), attitude recovery time < 2 seconds;

[0060] Endurance Time: The endurance time of a 2000mAh battery at full charge is 18 minutes (no load).

[0061] 8. Safety Mechanisms

[0062] Out-of-Control Protection: When the signal is lost for more than 2 seconds, the automatic landing program is started, and the speed is reduced by 0.5m / s until it touches the ground;

[0063] Emergency Shutdown: When the gyroscope detects abnormal rolling (angle > 45°), the power supply of the motor is immediately cut off;

[0064] Anti-Collision Design: The edges of the 600-film wings are wrapped with silica gel guards, which can absorb 80% of the impact energy.

[0065] 9. Overall Working Principle and Advantage Summary

[0066] The overall working principle is: The swinging angle and direction of the universal rod 5041 are controlled by 3 servos, and the direction and magnitude of the lift generated by the wings 600 are controlled to achieve hovering, rolling, pitching, and yawing; The rotation of the roll servo 501 and the pitch servo 502 drives the bottom components to move, changing the center of gravity position of the aircraft, and cooperating to improve stability.

[0067] Core Advantages: Simple and reliable structure, low manufacturing cost: Modular design reduces the assembly difficulty; Strong anti-interference ability, flexible control: The dual-effect control mechanism (lift + center of gravity) adapts to complex environments; Lightweight and durability: The combination of carbon fiber and PE film, lifespan ≥ 500 hours.

[0068] The above are only embodiments of the present invention, and thus do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall similarly be included within the patent protection scope of the present invention.

Claims

1. A bionic flapping-wing aircraft, characterized in that: include Main frame (100); A power source (200) is arranged on the main frame (100); A power transmission mechanism (300) connected to the power source (200) and used for converting the rotational motion of the power source (200) into a low-speed high-torque output; A reciprocating motion mechanism (400) connected to the power transmission mechanism (300) converts the low-speed high-torque output into a reciprocating flapping motion of the wings (600); The attitude control mechanism (500) comprises a plurality of steering gears, which independently control the rolling, pitching and yaw movements of the aircraft, adjust the lift direction by changing the angle of attack of the wings (600), and synchronously adjust the center of gravity position of the aircraft to achieve coordinated control of the flight attitude; Wings (600), connected to the reciprocating motion mechanism (400), generating lift by reciprocating flapping; A power source (700) is used to supply power to the power source (200) and the steering gear.

2. A bionic flapping-wing aircraft according to claim 1, characterized in that: The power transmission mechanism (300) comprises a reduction gear set, and the reduction gear set is connected to the reciprocating mechanism (400) via a crankshaft (404).

3. A bionic flapping-wing aircraft according to claim 1, characterized in that: The reciprocating mechanism (400) comprises a sliding tooth (401), a symmetrically arranged swinging tooth (402), a connecting rod (403) and a crankshaft (404), a symmetrically arranged pin shaft (405) and a fixed shaft (406); the sliding tooth (401) is connected to the crankshaft (404) via the connecting rod (403); the fixed shaft (406) horizontally passes through the sliding tooth (401) along the front-rear direction of the aircraft and is fixed on the main frame (100); the rotational motion of the crankshaft (404) is converted into a linear reciprocating motion of the sliding tooth (401); the swinging tooth (402) is installed on both sides of the main frame (100) via the pin shaft (405); the meshing of the racks on both sides of the sliding tooth (401) drives the rotational motion of the swinging tooth (402), thereby driving the wings (600) to flap.

4. A bionic flapping-wing aircraft according to claim 1, characterized in that: The attitude control mechanism (500) comprises a roll servo (501), a pitch servo (502), a yaw servo (503), a cross universal joint (504), a base (505) and a swing frame (506); the output shaft axes of the roll servo (501) and the pitch servo (502) are perpendicularly intersected; the pitch servo (502) is connected to the base (505) via a cross universal joint (504); and the yaw servo (503) drives the swing frame (506) to rotate so as to adjust the difference in attack angles of the wings (600) on both sides.

5. A bionic flapping-wing aircraft according to claim 4, characterized in that: A symmetrically arranged universal rod (5041) is provided between the main frame (100) and the swing frame (506), and the geometric layout of the universal rod (5041) satisfies the following requirements: the upper and lower ends of the universal rod (5041) are both spherical, the upper end is connected to the main frame (100) to form a ball head universal joint and is located directly below the pin shaft (405), that is, the spherical center point of the upper end is located on the extended axis of the pin shaft (405); the lower end is connected to the swing frame (506) to also form a ball head universal joint, the distance between the upper end ball centers of the universal rods (5041) on both sides is equal to the distance between the lower end ball centers, and the connecting line of the upper end ball centers intersects the axis of the output shaft of the roll servo (501) at right angles.

6. A bionic flapping-wing aircraft according to claim 1, characterized in that: The wing (600) comprises a flexible film and a supporting frame, one end of the supporting frame is fixed on the swinging tooth (402), the root of the flexible film is connected to the universal rod (5041), and the film tension is adjusted by the swing of the universal rod (5041) to change the angle of attack.

7. The bionic flapping-wing aircraft according to claim 1, characterized in that: The power source is fixed below the front and rear bases (505) at the bottom of the aircraft, and moves synchronously with the action of the attitude control mechanism (500) to adjust the center of gravity position.

8. The bionic flapping-wing aircraft according to claim 1, characterized in that: The maximum yaw rotation angle of the attitude control mechanism (500) is ±30°.

9. A bionic flapping-wing aircraft according to claim 4, characterized in that: The axis of the output shaft of the roll servo (501) and the axis of the output shaft of the pitch servo (502) intersect perpendicularly at point A, and the center of the cross axis of the cross universal joint (504) is point B. Then, the straight line AB from point A to point B is perpendicular to the axis of the output shaft of the pitch servo (502).

10. The bionic flapping-wing aircraft according to claim 6, characterized in that: The spherical center points of the upper end of the universal rod (5041) are respectively points C and D, and the spherical center points of the lower end are respectively points E and F; the straight line distance CD from point C to point D is equal to the straight line distance EF from point E to point F (CD=EF), and the straight line distance CE from point C to point E is equal to the straight line distance DF from point D to point F (CE=DF), then AB=CE=DF, CD is perpendicular to the axis of the output shaft of the roll servo (501) and intersects at point H, that is, the straight line AH from point A to point H is the perpendicular bisector of CD; the swing frame (506) is installed on the output shaft of the yaw servo (503) and the vertical distance from the spherical center of the lower end to the output shaft of the yaw servo is equal, that is, the axis of the output shaft of the yaw servo perpendicularly bisects EF at point K, and at this time AH=BK.

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