A biomimetic flapping-wing aircraft with variable fuselage attitude

Abstract

This invention relates to a biomimetic flapping-wing aircraft with variable fuselage attitude, comprising a frame, a motor fixed to the frame, and wings symmetrically arranged on the left and right sides of the frame. The wings include a crank-rocker mechanism hinged to the frame, a four-bar linkage movably passing through the frame, and a flapping rod. The motor drives the crank-rocker mechanism to rotate; the crank-rocker mechanism is connected to the four-bar linkage to drive it in a reciprocating oscillating motion; the flapping rod is fixed to the outside of the four-bar linkage. The wing employs a two-segment flapping mechanism, which helps reduce drag from upward flapping while ensuring lift from downward flapping, improving the overall energy utilization rate. The biomimetic flapping-wing aircraft uses a segmented structure with variable fuselage attitude, making it more agile and biomimetic. It can mimic various basic bird movements, enabling flapping flight, high-altitude emergency stops, and turning maneuvers.

Description

Technical Field

[0001] This invention belongs to the field of flapping-wing flight technology, specifically relating to a biomimetic flapping-wing aircraft with variable fuselage attitude. Background Technology

[0002] An ornithopter is a heavier-than-air aircraft whose wings flap up and down like those of birds and insects. Unlike traditional fixed-wing and rotary-wing aircraft, the biomimetic ornithopter is a new type of aircraft based on biomimetic principles. Its most distinctive feature is that it generates lift and thrust through the periodic flapping of its wings, and controls its flight direction by changing the position of its tail fin. It can effectively mimic the flight maneuvers of birds, such as high-altitude hovering and rapid flight.

[0003] Most existing flapping-wing aircraft are single-segment, meaning they consist of only one wing segment. While these aircraft have a simple structure, they suffer from drawbacks such as poor biomimicry, high drag during upward flapping motion, and an inability to guarantee lift during downward flapping motion, resulting in low energy efficiency and slow flight speed. Summary of the Invention

[0004] To address the technical problems existing in the prior art, the purpose of this invention is to provide a biomimetic flapping-wing aircraft with variable fuselage attitude, which has good biomimetic properties, can reduce the drag caused by the upward flapping motion and ensure the lift caused by the downward flapping motion, improve the overall energy utilization rate of the aircraft, and has a high flight speed.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A biomimetic flapping-wing aircraft with variable fuselage attitude includes a frame, a motor fixed to the frame, and wings symmetrically arranged on the left and right sides of the frame.

[0007] The wing includes a crank-rocker mechanism hinged to the frame, a four-bar linkage that moves through the frame, and a flapping rod;

[0008] The motor drive is connected to the crank-rocker mechanism to drive the crank-rocker mechanism to rotate;

[0009] The crank-rocker mechanism is connected to the four-bar linkage and is used to drive the four-bar linkage to perform reciprocating oscillating motion.

[0010] The flapping rod is fixed to the outside of the four-bar linkage.

[0011] Furthermore, the four-bar linkage is a parallelogram.

[0012] Furthermore, the crank-rocker mechanism includes a large gear, which is hinged to the frame. A motor drive is connected to the large gear. The four-bar linkage includes a first short rod and a second short rod arranged opposite to each other, and a first long connecting rod disposed between the first short rod and the second short rod. The first short rod is offset and hinged to the large gear. The flapping long rod is fixed to the outside of the second short rod. The first long connecting rod is movably inserted through the frame.

[0013] Furthermore, the angle between the flapping long rod and the second short rod is θ, where 40°≤θ≤50°.

[0014] Furthermore, streamlined feather supports are installed on the flapping rod and the first long connecting rod, and the feather supports are fitted with wing sails.

[0015] Furthermore, it also includes a swing servo, a first ball joint hinge, and a fuselage platform. The fuselage platform is hinged to the end of the frame, and the swing servo is fixed to the frame. The swing servo is connected to the fuselage platform through the first ball joint hinge and is used to drive the fuselage platform to swing up and down relative to the frame.

[0016] Furthermore, the oscillating servo is located at the rear of the frame, which also houses a battery that powers the oscillating servo and motor.

[0017] Furthermore, a second ball joint hinge and a tail fin are provided at the rear of the fuselage platform. The tail fin is hinged to the fuselage platform. A left servo and a right servo are symmetrically fixed on the fuselage platform. The left servo and the right servo are respectively connected to the tail fin via the second ball joint hinge, which is used to drive the tail fin to deflect left and right or up and down.

[0018] Furthermore, a tailstock and a hinge are located below the tail fin mount. The tail fin mount is hinged to the tailstock, and the fuselage platform is connected to the tailstock via the hinge.

[0019] Furthermore, a tail sail is fixed to the rear end of the tail fin mount.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The wing flaps in one stage by using a crank-rocker mechanism to drive a four-bar linkage in a reciprocating oscillating motion. During this oscillating motion, the angles between the links in the four-bar linkage constantly change, causing the flapping link to swing up and down with the linkage, thus creating the second stage of flapping. This two-stage flapping mechanism helps reduce drag from the upward flapping motion while ensuring lift from the downward flapping motion, improving overall energy efficiency and increasing flight speed.

[0022] The biomimetic flapping-wing aircraft adopts a segmented structure and has a variable fuselage attitude, making the flapping-wing aircraft more agile and biomimetic.

[0023] The tail fin uses a parallel structure, which is compact and flexible, and can easily control the flight direction of the biomimetic flapping-wing aircraft. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the planar structure from a first perspective of an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the planar structure from a second perspective of an embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram of the planar structure from a third perspective of an embodiment of the present invention.

[0028] Figure 5 A schematic diagram of the upward flapping motion of a biomimetic flapping-wing aircraft (only one wing is shown).

[0029] Figure 6 This is a schematic diagram of the downward movement of a biomimetic flapping-wing aircraft (only one wing is shown).

[0030] Figure 7 This is a control flowchart of an embodiment of the present invention.

[0031] 1-Second short rod, 2-First long connecting rod, 3-Second long connecting rod, 4-First short rod, 5(5`)-Large gear, 6-Motor, 7-Small gear, 8(8`)-Second ball joint hinge, 9-Tail wing frame, 10-Servo arm, 11-Left servo, 11`-Right servo, 12-First ball joint hinge, 13-Frame, 14-Fuselage platform, 15-Hinge, 16-Oscillating servo, 17-Tail frame, 18-Feather support, 19-Flapping long rod. Detailed Implementation

[0032] Most existing flapping-wing aircraft are single-segment flapping-wing aircraft. These types of aircraft suffer from drawbacks such as poor biomimicry, low energy efficiency, and slow flight speed. Furthermore, the fuselage of many flapping-wing aircraft is fixed, making it difficult to perform certain bird flight maneuvers, such as high-altitude abrupt stops or hovering. To address these existing technical problems, this invention aims to provide a biomimetic flapping-wing aircraft with a variable fuselage attitude. It employs a two-segment flapping-wing structure design, enabling different upward and downward flapping maneuvers, reducing drag from upward flapping maneuvers, and improving energy efficiency and flight speed. Moreover, it utilizes a segmented, variable fuselage, allowing the aircraft's center of gravity to be adjusted as needed, causing the aircraft to tilt and enabling maneuvers such as high-altitude abrupt stops or hovering, thus improving the biomimicry and flexibility of the flapping-wing aircraft.

[0033] The present invention will now be described in further detail.

[0034] 1. Wings

[0035] The frame 13 has wings symmetrically arranged on both sides. The wings adopt a two-stage flapping mechanism with a first wing and a second wing, including a crank rocker mechanism hinged to the frame 13, a four-bar linkage mechanism movably passing through the frame 13, and a flapping rod 19.

[0036] Specifically, such as Figures 1-4 As shown, the flapping mechanism is powered by a motor 6 with a built-in gearbox, and the motor 6 is directly connected to a pinion 7. Symmetrically arranged on both sides of the frame 13 are large gears 5' and 5' that mesh with each other. The meshing transmission of large gears 5' and 5' ensures the consistent symmetry of the flapping mechanism's movements on both sides.

[0037] The four-bar linkage is a parallelogram-shaped, double-crank mechanism, comprising a first short link 4 and a second short link 1 arranged opposite each other, and a first long link 2 and a second long link 3 located between the first short link 4 and the second short link 1. The first long link 2 serves as one section of the wing. As the second section of the wing, a flapping long link 19 is fixed to the second short link 1, and there is an angle of 40°-50° between the flapping long link 19 and the second short link 1. Preferably, there is a 45° angle between the flapping long link 19 and the second short link 1, and the flapping long link 19 and the second short link 1 are integrally formed.

[0038] The flapping pole 19, the first long connecting rod 2, and the second long connecting rod 3 are each equipped with three streamlined feather supports 18, and the feather supports 18 are fitted with wing sails. The wing sails are made of lightweight materials with good sealing properties.

[0039] The first short rod 4 is a multi-part component with three rotating joints. The first is offsetly connected to the large gear 5, the second is connected to the second long connecting rod 3, and the third is connected to the first long connecting rod 2.

[0040] The large gear 5, the first short rod 4, the first long connecting rod 2, and the frame 13 constitute a crank-rocker mechanism. The large gear 5' and the large gear 5 have openings that act as the cranks of the crank-rocker mechanism in the flapping mechanism. The first long connecting rod 2 is connected to the frame 13 through a rotating joint.

[0041] When the large gear 5 rotates, the angle between the second long connecting rod 3 and the first short rod 4 changes. Since opposite angles of a parallelogram are equal, the angle between the second short rod 1 and the first long connecting rod 2 also changes in the same way. The rotation of the motor 6 drives the small gear 7 to rotate, which in turn drives the large gear 5 to rotate. The rotation of the large gear 5, acting as a crank, causes the first long connecting rod 2, acting as a rocker arm, to reciprocate and swing, thus forming the flapping motion of one segment of the wing. The change in the angle between the second long connecting rod 3 and the first short rod 4 causes a change in the angle between the first long connecting rod 2 and the second short rod 1, thereby causing the flapping rod 19 to swing up and down with the four-bar linkage, thus forming the flapping motion of the two-segment wing.

[0042] In the flapping flight motion composed of the flapping of the two wings, the motor 6 rotates continuously, driving the small gear 7 to rotate, the small gear 7 drives the large gear 5' to rotate, the large gear 5' drives the first long connecting rod 2 to swing up and down periodically.

[0043] During the upward flapping motion of the biomimetic flapping-wing aircraft, the large gear 5 gradually rotates, as... Figure 5 As shown, the wing states are shown in sequence as ①, ②, ③, and ④. The angle between the first short rod 4 and the second long connecting rod 3 gradually decreases. Since the angle between opposite sides of a parallelogram is equal, the angle between the second short rod 1 and the first long connecting rod 2 of the first section of the wing also decreases. The angle between the flapping long rod 19 and the first long connecting rod 2 also decreases. That is, the first section of the wing and the second section of the wing are folded together, and the wind resistance area is reduced.

[0044] As the large gear 5 continues to rotate, the biomimetic flapping-wing aircraft performs its descent, as... Figure 6 As shown, the wing states are shown in sequence as ⑤, ⑥, ⑦, and ⑧. The angle between the first short rod 4 and the second long connecting rod 3 increases. Since the angle between opposite sides of a parallelogram is equal, the angle between the second short rod 1 and the first long connecting rod 2 increases. The angle between the flapping long rod 19 and the first long connecting rod 2 also increases. That is, the first and second wing sections are deployed, and the drag area increases.

[0045] By folding and unfolding the first and second wing sections, the drag caused by the upward movement is reduced while the lift caused by the downward movement is increased, which is beneficial to improving flight speed.

[0046] 2. Fuselage

[0047] like Figure 3 As shown, the fuselage, equivalent to the waist of a biomimetic flapping-wing aircraft, is a dual-rocker mechanism, including a first ball joint hinge 12, a frame 13, a fuselage platform 14, a hinge 15, and a sway servo 16. The fuselage platform 14 is connected to the frame 13 via the hinge 15, and the sway servo 16 is fixed to the frame 13 and connected to the fuselage platform 14 via the first ball joint hinge 12. Rotation of the output shaft of the sway servo 16 causes the fuselage platform 14 to sway up and down. The fuselage platform 14 houses components with a relatively high weight proportion, such as the battery and the sway servo 16, making its weight proportion relatively high. This allows for easier adjustment of the overall center of gravity by adjusting the attitude of the fuselage platform 14, thus adapting to the needs of flight. In the event of an emergency stop at high altitude, the swing servo 16 rotates to push the first ball joint hinge 12, causing the fuselage platform 14 to swing downwards. The overall center of gravity shifts downwards, the entire fuselage deflects downwards, and the direction of the aerodynamic force generated by the flapping of the wings on both sides changes from vertical to horizontal, enabling the aircraft to achieve a greater deceleration and thus achieve an emergency stop.

[0048] 3. Tail wing

[0049] like Figure 4As shown, the tail fin is a parallel mechanism, including a second ball joint hinge 8 (8'), a tail fin mount 9, a left servo motor 11, a right servo motor 11', and a tailstock 17. The left and right servo motors 11 and 11' are symmetrically fixed to the fuselage platform 14, which is connected to the tailstock 17 via hinges. The tail fin mount 9 is connected to the tailstock 17 via a revolute joint and to the servo arms 10 of the left and right servo motors 11 and 11' via the second ball joint hinge 8 (8'). The tailstock 17 is the support platform for the tail fin mount 9, and the two revolute joints on the tailstock 17 provide the entire tail fin with two degrees of freedom for vertical and horizontal oscillation.

[0050] By adjusting the different rotational offset positions of the left servo 11 and the right servo 11', the tail fin can be made to deflect left and right and up and down: when the left servo 11 and the right servo 11' rotate in opposite directions at the same angle, the tail fin can be deflected up and down; when the left servo 11 and the right servo 11' rotate in the same direction at different angles, the tail fin can be made to deflect left and right, and the tail fin deflects towards the servo with the larger rotation angle.

[0051] The tail fin 9 is fixed to the rear end with a tail sail. Specifically, the tail fin 9 has three long rods extending rearward and covered with a fan-shaped thin material to provide aerodynamic power during flight turns.

[0052] This embodiment describes a biomimetic flapping-wing aircraft with variable fuselage attitude. The control process is as follows: Figure 7 As shown, a microcontroller and related circuits drive and control motor 6 and various servos. Signals are sent via a controller to remotely control the bionic flapping-wing aircraft. A gyroscope sensor is installed on the fuselage to detect its pitch and horizontal turning angles, using these as indicators of deviation between the aircraft's flight state and the commanded state to adjust its movements for stable flight. The bionic flapping-wing aircraft has four degrees of freedom: periodic flapping motion controlled by a single degree of freedom, vertical oscillation of the fuselage controlled by a single degree of freedom, and vertical and horizontal oscillation of the tail fin controlled by two degrees of freedom. It can mimic various basic bird movements, enabling flapping flight, high-altitude emergency stops, and turning maneuvers.

[0053] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A biomimetic flapping-wing aircraft with variable fuselage attitude, characterized in that: It includes a frame, a motor fixed to the frame, and wings symmetrically arranged on the left and right sides of the frame; The wing includes a crank-rocker mechanism hinged to the frame, a four-bar linkage that moves through the frame, and a flapping rod; The motor drive is connected to the crank-rocker mechanism to drive the crank-rocker mechanism to rotate; The crank-rocker mechanism is connected to the four-bar linkage and is used to drive the four-bar linkage to perform reciprocating oscillating motion. The flapping rod is fixed to the outside of the four-bar linkage. It also includes a swing servo, a first ball joint hinge and a fuselage platform. The fuselage platform is hinged to the end of the frame, and the swing servo is fixed to the frame. The swing servo is connected to the fuselage platform through the first ball joint hinge and is used to drive the fuselage platform to swing up and down relative to the frame. The four-bar linkage is a parallelogram; A second ball joint hinge and a tail fin are located at the rear of the fuselage platform. The tail fin is hinged to the fuselage platform. A left servo and a right servo are symmetrically fixed to the fuselage platform. The left servo and the right servo are respectively connected to the tail fin via the second ball joint hinge, which is used to drive the tail fin to deflect left and right or up and down.

2. A biomimetic flapping-wing aircraft with variable fuselage attitude according to claim 1, characterized in that: The crank-rocker mechanism includes a large gear, which is hinged to the frame. A motor drive is connected to the large gear. The four-bar linkage includes a first short rod and a second short rod arranged opposite to each other, and a first long connecting rod located between the first short rod and the second short rod. The first short rod is offset and hinged to the large gear. The long connecting rod is fixed to the outside of the second short rod. The first long connecting rod is movably inserted through the frame.

3. A biomimetic flapping-wing aircraft with variable fuselage attitude according to claim 2, characterized in that: The angle between the long pole and the second short pole is θ, where 40º≤θ≤50º.

4. A biomimetic flapping-wing aircraft with variable fuselage attitude according to claim 2, characterized in that: The flapping pole and the first long connecting rod are each equipped with a streamlined feather support, and the feather support is fitted with a wing sail.

5. A biomimetic flapping-wing aircraft with variable fuselage attitude according to claim 1, characterized in that: The oscillating servo is located at the rear of the frame, which also houses a battery that powers the oscillating servo and motor.

6. A biomimetic flapping-wing aircraft with variable fuselage attitude according to claim 1, characterized in that: The tailstock and hinge are located below the tail fin mount. The tail fin mount is hinged to the tailstock, and the fuselage platform is connected to the tailstock via the hinge.

7. A biomimetic flapping-wing aircraft with variable fuselage attitude according to claim 1, characterized in that: A tail sail is fixed to the rear end of the tail fin mount.

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