A flapping angle adjustable dragonfly-like flapping wing aircraft and a flight method thereof

Abstract

The present application relates to the technical field of flapping-wing aircraft, and particularly relates to a flapping-wing aircraft with adjustable attack angle of dragonfly and a flight method thereof. The flapping-wing aircraft comprises a body, a flapping-wing assembly, a universal flapping mechanism and a flapping-wing driving mechanism. The body comprises a fuselage, and the flapping-wing assembly, the universal flapping mechanism and the flapping-wing driving mechanism are all mounted on the fuselage. The flapping-wing assembly comprises four flapping wings, the universal flapping mechanism has four universal flapping mechanisms and is connected with the flapping wings one by one respectively. The flapping-wing driving mechanism is connected with the universal flapping mechanism and drives the flapping wings to perform flapping motion. The universal flapping mechanism can independently adjust the attack angle of the corresponding flapping wing. The flapping-wing aircraft of the present application can reduce the number of driving elements, reduce the weight and energy consumption of the whole machine, and improve the maneuverability, reliability and endurance of the aircraft under the premise of ensuring the independent adjustment of the attack angle of the four flapping wings.

Description

Technical Field

[0001] This invention relates to the field of flapping-wing aircraft technology, and in particular to a flapping-wing aircraft with adjustable angle of attack, mimicking a dragonfly flapping-wing aircraft and its flight method. Background Technology

[0002] Flapping-wing aircraft are unmanned aerial vehicles (UAVs) that mimic the flight patterns of insects or birds in nature. They generate lift and thrust by flapping their wings and possess advantages such as vertical takeoff and landing, hovering, and low-speed maneuverability. They are suitable for missions in confined spaces and complex environments, such as indoor search and rescue, pipeline inspection, and forest canopy observation. Dragonflies, as insects with outstanding flight capabilities in nature, have two pairs of wings that can move independently, possessing high maneuverability such as hovering, inverted flight, and side flight. Therefore, they have become an important reference for the design of biomimetic flapping-wing aircraft.

[0003] Currently, most dragonfly-inspired flapping-wing aircraft employ a combination of motors and servos to achieve independent drive and control of their four flapping wings. In a typical structure, each flapping wing is usually equipped with at least two servos or motors to control its flapping amplitude, frequency, or angle of attack. While this design allows for highly independent control of wing movement, it results in a complex overall aircraft structure, significantly increased weight, higher energy consumption, and lower transmission efficiency, severely limiting the aircraft's maneuverability and endurance. Furthermore, multi-motor / servo systems also introduce problems such as complex control algorithms and reduced reliability.

[0004] Therefore, existing dragonfly-like flapping-wing aircraft have the following technical problems: First, since each flapping wing requires an independent drive mechanism, the number of parts in the whole machine is large and the structure is redundant, making it difficult to achieve lightweight design; second, the simultaneous operation of multiple motors and servos will significantly increase power consumption and reduce flight time. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a dragonfly-inspired flapping-wing aircraft with adjustable angle of attack and its flight method. A single main actuator provides the primary flapping power, supplemented by small servo mechanisms to independently control the angle of attack or amplitude of each wing, achieving differential control of the dragonfly-inspired flapping-wing aircraft. While ensuring independent adjustment of the angle of attack for each of the four flapping wings, the number of drive components is reduced, lowering the overall weight and energy consumption, and improving the aircraft's maneuverability, reliability, and endurance.

[0006] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0007] A dragonfly-inspired flapping-wing aircraft with adjustable flapping angle of attack includes a body, flapping wing components, a gimbal flapping mechanism, and a flapping wing drive mechanism. The body includes a fuselage, and the flapping wing components, gimbal flapping mechanism, and flapping wing drive mechanism are all mounted on the fuselage. The flapping wing components include four flapping wings, and the gimbal flapping mechanism has four flapping wings, each connected to one of the flapping wings. The flapping wing drive mechanism is connected to the gimbal flapping mechanism and drives the flapping wings to flap. The gimbal flapping mechanism can independently adjust the angle of attack of the corresponding flapping wing.

[0008] Optionally, the flapping wing assembly includes a left front flapping wing, a right front flapping wing, a right rear flapping wing, and a left rear flapping wing. The left front flapping wing and the right front flapping wing are symmetrically installed on the front of both sides of the fuselage, and the left rear flapping wing and the right rear flapping wing are symmetrically installed on the rear of both sides of the fuselage.

[0009] Optionally, the flapping wing drive mechanism includes a dual-output shaft motor, a drive shaft, a worm, a worm wheel, a worm wheel shaft, a crank, and a connecting rod; the front and rear output shafts of the dual-output shaft motor are respectively connected to the front and rear worms via the drive shaft; each worm meshes with a worm wheel, and each worm wheel is fixed to a worm wheel shaft; each end of each worm wheel shaft is provided with a crank; each crank is hinged to a universal flapping mechanism via a connecting rod.

[0010] Optionally, the two cranks on the front worm gear shaft and the two cranks on the rear worm gear shaft are installed at angles 180 degrees apart, so that the flapping motion of the front and rear pairs of flapping wings has a phase difference of half a cycle.

[0011] Optionally, the universal joint flapping mechanism includes a universal joint inner ring, a universal joint middle ring, a universal joint outer ring, and a universal joint flapping frame; the universal joint inner ring is installed inside the universal joint middle ring via two upper and lower inner ring pivots; the universal joint middle ring is installed inside the universal joint outer ring via two left and right middle ring pivots; the universal joint outer ring is slidably disposed within the universal joint flapping frame.

[0012] Optionally, the root of the flapping wing is a square shaft structure, which is inserted into the square through hole in the inner ring of the universal joint and can slide relative to it; the flapping wing is connected to the ball head support fixed to the fuselage through the hemispherical recess at the root to form a spherical joint hinge.

[0013] Optionally, the universal flapping mechanism is rotatably mounted on a circular platform on the side wall of the fuselage via a shaft hole structure on the universal flapping frame; each universal flapping mechanism is connected to a flapping wing rotation servo; a drive gear is fixed on the output shaft of the flapping wing rotation servo, and a driven gear ring is fixed on the universal flapping frame, with the drive gear and the driven gear ring meshing with each other.

[0014] Optionally, the rotation range of the omnidirectional flapping mechanism is limited to two extreme positions with a rotation angle of 90 degrees; when the omnidirectional flapping mechanism is in the extreme position, the wing surface of the corresponding flapping wing is in a horizontal or vertical state.

[0015] Optionally, the machine body also includes a tail section, which includes a rear base fixed to the rear end of the machine body, multiple elastic tail rods, a counterweight slider slidably sleeved on the tail rods, and a front base connected to the front end of the tail rods; the counterweight slider is provided with through holes corresponding to the number of tail rods, and the tail rods pass through the through holes.

[0016] This invention also provides a flight method for the dragonfly-inspired flapping-wing aircraft with adjustable angle of attack as described above, comprising:

[0017] A single drive motor simultaneously drives four flapping wings to perform synchronized reciprocating flapping motions.

[0018] The rotation angle of each of the four omnidirectional flapping mechanisms is controlled by four independent flapping wing rotation servos, thereby independently adjusting the angle of attack of each flapping wing;

[0019] When it is necessary to change the flight attitude, the angle of attack of at least one flapping wing is changed relative to the other flapping wings, causing the lift or drag generated on both sides or in front and behind the aircraft to become unbalanced, thereby generating a moment that causes the aircraft to yaw, roll or pitch.

[0020] By controlling the flapping motion of the front pair of flapping wings and the rear pair of flapping wings to maintain a 180-degree phase difference, the unbalanced force generated during the flapping process can be counteracted, thereby reducing the vibration of the aircraft.

[0021] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0022] 1. The dragonfly-like flapping-wing aircraft of the present invention includes a fuselage, flapping wing components, a gimbal flapping mechanism, and a flapping wing drive mechanism. The fuselage serves as an integral support structure, and the flapping wing components, gimbal flapping mechanism, and flapping wing drive mechanism are all arranged on the fuselage. The flapping wing components have four flapping wings, and the number of gimbal flapping mechanisms corresponds to the number of flapping wings and is connected to each flapping wing. The flapping wing drive mechanism is responsible for providing the power required for the flapping wing movement and is connected to the gimbal flapping mechanism. The gimbal flapping mechanism can independently adjust the angle of attack of the connected flapping wing without interfering with the flapping wing movement. This aircraft achieves differential control of a four-flapping-wing aircraft through a single drive source combined with multiple independently controlled gimbal flapping mechanisms, reducing the number of actuators, contributing to the overall lightweight design, and reducing energy consumption. At the same time, the angle of attack of each flapping wing can be adjusted independently, improving the controllability and maneuverability of the aircraft, enabling it to achieve various dragonfly-like flight maneuvers.

[0023] 2. The structure is safe and reliable, with high transmission efficiency and large output force and torque. It uses common mechanical components such as gears, worm gears, worms, and connecting rods as the main components of the transmission system. The worm gear mechanism reduces the output of the drive motor and increases the torque. The crank-slider mechanism drives the flapping wings to flap back and forth. The structure is simple and the motion law is easy to control.

[0024] 3. The whole machine is lightweight, has high structural strength, and is easy to process and manufacture. Unlike common designs that pile up a large number of servo motors and motors, this invention can drive and control a four-flapping dragonfly-like flapping-wing aircraft using only one motor and four servo motors. It uses fewer parts and has a compact structure.

[0025] 4. It has a high degree of freedom of movement. The flapping frequency of the four flapping wings is controllable, and the angle of attack of the four flapping wings can be controlled independently. It can flap at different angles of attack and can perform actions such as yaw, roll, sudden stop, and inverted flight.

[0026] Advantages of additional aspects of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In addition, the dimensions or spacing between the components are exaggerated to show the position of each component, and the schematic diagrams are for illustrative purposes only.

[0028] Figure 1 This is a schematic diagram of a flapping-wing aircraft with adjustable angle of attack, mimicking a dragonfly flapping wing, provided in an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the fuselage structure in an embodiment of the present invention.

[0030] Figure 3 This is a structural and installation diagram of the flapping wing drive mechanism in an embodiment of the present invention.

[0031] Figure 4 This is a schematic diagram of the universal flapping mechanism in an embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the installation and assembly of the left front flapping wing in an embodiment of the present invention.

[0033] Figure 6 This is a schematic diagram of the tail section in an embodiment of the present invention.

[0034] Figure 7 This is a schematic diagram of the left front flapping wing flapping up and down to its highest position in an embodiment of the present invention.

[0035] Figure 8 This is a schematic diagram of the left front flapping wing flapping up and down to its lowest position in an embodiment of the present invention.

[0036] Figure 9 This is a schematic diagram of the left front flapping wing flapping at its foremost position when the angle of attack is 90 degrees in an embodiment of the present invention.

[0037] Figure 10 This is a schematic diagram of the left front flapping wing flapping to its final position when the angle of attack is 90 degrees in an embodiment of the present invention.

[0038] Figure 11 This is a schematic diagram showing the positional relationship between the omnidirectional flapping mechanism and other mechanisms when the flapping wings flap forward and backward in an embodiment of the present invention.

[0039] Figure 12 This is a schematic diagram showing the positional relationship between the omnidirectional flapping mechanism and other mechanisms when the flapping wings flap up and down in an embodiment of the present invention.

[0040] Figure 13 This is a schematic diagram of how the left front flapping wing changes its angle of attack to achieve steering in an embodiment of the present invention.

[0041] In the diagram: 1. Left front flapping wing; 2. Universal flapping mechanism; 3. Fuselage; 4. Right front flapping wing; 5. Right rear flapping wing; 6. Tail; 7. Left rear flapping wing; 8. Flapping wing drive mechanism; 21. Universal joint inner ring; 22. Inner ring shaft; 23. Universal joint middle ring; 24. Middle ring shaft; 25. Flapping wing rotation driven gear ring; 26. Universal flapping frame; 27. Universal joint outer ring; 31. Flapping wing ball joint support; 32. Fuselage frame; 33. Worm gear fixing plate; 34. Flapping wing rotation drive gear; 35. Flapping wing rotation servo; 61. Tail rear base; 62. Counterweight slider; 63. Tail rod; 64. Tail front base; 81. Dual output shaft motor; 82. Crank; 83. Worm gear shaft; 84. Worm gear; 85. Worm; 86. Connecting rod; 87. Drive shaft; Detailed Implementation

[0042] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0043] Example 1

[0044] To improve the maneuverability and controllability of the dragonfly-like flapping-wing aircraft, it is necessary to control the four flapping wings on the fuselage to mimic the flapping motion of a dragonfly as much as possible during flight, while simultaneously increasing the degrees of freedom of each flapping wing within controllable parameters. A straightforward method to increase the degrees of freedom is to use servos, motors, or other components to directly or indirectly drive the flapping wing movement. Typically, one servo or motor can control movement in at least one direction. However, a large number of servos and motors would significantly increase the aircraft's weight and energy consumption, affecting its maneuverability and range, which contradicts the design goals of the dragonfly-like flapping-wing aircraft.

[0045] Based on this, this embodiment provides a dragonfly-like flapping-wing aircraft with adjustable flapping angle of attack. The left front flapping wing 1, right front flapping wing 4, right rear flapping wing 5, and left rear flapping wing 7 can have their flapping angle of attack independently controlled by a universal flapping mechanism 2 that cooperates with the root of the flapping wing. After the flapping wing drive mechanism 8, arranged in the middle of the fuselage frame 32, is combined with the universal flapping mechanism 2, the rotary motion output by the motor can be converted into the reciprocating flapping motion of the four flapping wings. Under the joint action of the flapping wing drive mechanism 8 and the flapping wing rotation servo 35, the universal flapping mechanism 2 can independently and freely change the angle of attack of any flapping wing without affecting the normal flapping of the wings.

[0046] like Figure 1 As shown, this embodiment proposes a dragonfly-like flapping-wing aircraft, including a body, flapping wing assembly, omnidirectional flapping mechanism 2, and flapping wing drive mechanism 8; the body includes a fuselage 3, and the flapping wing assembly, omnidirectional flapping mechanism 2, and flapping wing drive mechanism 8 are all mounted on the fuselage 3; the flapping wing assembly includes four flapping wings, and the omnidirectional flapping mechanism 2 has four flapping wings, each connected to one of the flapping wings; the flapping wing drive mechanism 8 is connected to the omnidirectional flapping mechanism 2 and drives the flapping wings to perform flapping motion; the omnidirectional flapping mechanism 2 can independently adjust the angle of attack of the corresponding flapping wing.

[0047] The fuselage 3, serving as the main load-bearing structure, provides a stable mounting base for the flapping wing assembly, the omnidirectional flapping mechanism 2, and the flapping wing drive mechanism 8. This ensures that the positions of each component remain relatively fixed during flight, preventing motion interference or power transmission loss due to loose installation. The four flapping wings of the flapping wing assembly are connected one-to-one with the four omnidirectional flapping mechanisms 2, allowing each flapping wing to obtain power and adjust its attitude through an independent omnidirectional flapping mechanism 2, eliminating the need for multiple independent drive units. The flapping wing drive mechanism 8 is directly connected to the omnidirectional flapping mechanisms 2, concentrating power to all four omnidirectional flapping mechanisms 2, thereby driving all flapping wings to flap synchronously.

[0048] The power output by the flapping wing drive mechanism 8 is transmitted to the flapping wing through the universal flapping mechanism 2, and is converted into the reciprocating flapping motion of the flapping wing to generate lift and thrust. At the same time, the universal flapping mechanism 2 can independently change the angle of attack of the corresponding flapping wing without interrupting the flapping motion, so as to realize the individual control of the motion state of each flapping wing.

[0049] The aircraft in this embodiment uses a single flapping wing drive mechanism 8 to centrally drive four flapping wings, replacing the design of multiple motors in the prior art. This reduces the number of drive components, significantly reduces the overall weight, reduces power consumption, extends the aircraft's endurance, and solves the problems of heavy weight and high energy consumption. Secondly, the four omnidirectional flapping mechanisms 2 independently adjust the angle of attack of their respective flapping wings, giving the aircraft higher degrees of freedom of movement. This allows it to perform complex maneuvers such as hovering, rapid maneuvering, side-flying, and inverted flight, improving maneuverability and solving the problems of low control freedom and insufficient maneuverability. Simultaneously, the components work together, and the load-bearing function of the fuselage 3 ensures the stability of power transmission. The omnidirectional flapping mechanism 2 combines power transmission and angle of attack adjustment functions, eliminating the need for an additional angle of attack adjustment mechanism, simplifying the overall structure, and reducing control complexity.

[0050] like Figure 1 As shown, the flapping wing assembly includes a left front flapping wing 1, a right front flapping wing 4, a right rear flapping wing 5, and a left rear flapping wing 7. The left front flapping wing 1 and the right front flapping wing 4 are symmetrically installed on the front of both sides of the fuselage 3, and the left rear flapping wing 7 and the right rear flapping wing 5 are symmetrically installed on the rear of both sides of the fuselage 3.

[0051] Symmetrical installation ensures balanced force distribution on the fuselage 3, allowing lift and thrust in the forward / backward and left / right directions to match during flight, reducing fuselage tilt caused by excessive force on one side and improving flight stability. Secondly, the symmetrical structure facilitates power distribution to the flapping wing drive mechanism 8, which can transmit power to the left and right flapping wings through symmetrical transmission paths, reducing power loss during transmission and improving transmission efficiency.

[0052] like Figure 3 As shown, the flapping wing drive mechanism 8 includes a dual-output shaft motor 81, a transmission shaft 87, a worm 85, a worm wheel 84, a worm wheel shaft 83, a crank 82, and a connecting rod 86. The front and rear output shafts of the dual-output shaft motor 81 are respectively connected to the front and rear worms 85 through the transmission shaft 87. Each worm 85 meshes with a worm wheel 84, and each worm wheel 84 is fixed to a worm wheel shaft 83. Each end of each worm wheel shaft 83 is provided with a crank 82. Each crank 82 is hinged to a universal flapping mechanism 2 through a connecting rod 86.

[0053] When the dual-output shaft motor 81 is running, its output rotational motion is transmitted to the front and rear worms 85 through the front and rear drive shafts 87 respectively. The worms 85 transmit the rotational motion to the worm wheel 84 through meshing with the worm wheel 84. At the same time, the speed reduction characteristic of the worm wheel 84 and worm 85 mechanism is used to reduce the speed and increase the torque. The worm wheel 84 drives the worm wheel shaft 83 to rotate, which in turn drives the cranks 82 at both ends of the worm wheel shaft 83 to perform circular motion. The circular motion of the cranks 82 is converted into the reciprocating linear motion of the universal joint outer ring 27 through the connecting rod 86, which finally drives the universal flapping mechanism 2 to drive the flapping wings to perform reciprocating flapping motion.

[0054] The dual-output-shaft motor 81 design allows a single motor to power both the front and rear flapping wings simultaneously, eliminating the need for separate motors at the front and rear of the fuselage 3. This reduces the number of motors and further lowers the overall weight and energy consumption. Secondly, the worm gear 84 and worm 85 mechanism have a significant speed reduction and torque amplification effect, converting the high speed and low torque output from the dual-output-shaft motor 81 into the low speed and high torque required for flapping wing operation. This ensures the flapping wings have sufficient power to overcome airflow resistance and avoids weak flapping or jerky movement due to insufficient torque. The crank 82 and connecting rod 86 mechanism smoothly converts rotational motion into reciprocating linear motion. The motion transmission process is continuous and without significant impact, reducing vibration during flapping wing operation, improving flight stability, and preventing component wear caused by uneven motion transitions, thus extending the mechanism's service life.

[0055] The reduction and torque increase of the worm gear 84 and worm 85 are coordinated with the motion conversion of the crank 82 and connecting rod 86 to ensure that the power output from the motor to the flapping wing process meets the torque requirements and achieves stable reciprocating motion. The setting of the transmission shaft 87 allows the motor to be installed in the middle of the fuselage 3, optimizes the center of gravity distribution of the fuselage 3, and works in synergy with the symmetrical installation of the flapping wing to further improve the overall balance of the machine.

[0056] The two cranks 82 on the front worm gear shaft 83 and the two cranks 82 on the rear worm gear shaft 83 are installed at angles 180 degrees apart, resulting in a half-cycle phase difference in the flapping motion of the front and rear pairs of flapping wings. This phase difference design effectively counteracts the unbalanced force generated by the flapping wings, extends the service life of the aircraft, and improves the stability of image acquisition for observation missions.

[0057] like Figure 4 , Figure 5 As shown, the universal joint flapping mechanism 2 includes a universal joint inner ring 21, a universal joint middle ring 23, a universal joint outer ring 27, and a universal joint flapping frame 26; the universal joint inner ring 21 is installed inside the universal joint middle ring 23 via two upper and lower inner ring pivots 22; the universal joint middle ring 23 is installed inside the universal joint outer ring 27 via two left and right middle ring pivots 24; the universal joint outer ring 27 is slidably disposed within the universal joint flapping frame 26.

[0058] The universal flapping mechanism 2 has two functions: First, it transmits the flapping motion. The connecting rod 86 of the flapping wing drive mechanism 8 drives the outer ring 27 of the universal joint to slide within the universal flapping frame 26. The outer ring 27 drives the middle ring 23 of the universal joint through the middle ring shaft 24. The middle ring 23 then drives the inner ring 21 of the universal joint through the inner ring shaft 22, ultimately driving the flapping wing connected to the inner ring 21 of the universal joint to perform an up-and-down flapping motion. Second, it adjusts the angle of attack. When the universal flapping frame 26 rotates, the rectangular step cooperates with the rectangular groove of the outer ring 27 of the universal joint to drive the outer ring 27, the middle ring 23, the inner ring 21 of the universal joint, and the flapping wing to rotate synchronously, thereby changing the angle of attack of the flapping wing. This rotational motion does not interfere with the sliding motion of the outer ring 27 of the universal joint.

[0059] The multi-layered universal structure allows the flapping wing to rotate around two vertical axes, satisfying both the up-and-down oscillation required for flapping motion and the rotation required for angle of attack adjustment. This eliminates the need for separate mechanisms for these two motions, simplifying the structure of the universal flapping mechanism 2, reducing the number of parts, and lowering weight and manufacturing costs. Secondly, the sliding engagement between the universal joint outer ring 27 and the universal flapping frame 26 provides stable guidance for the flapping motion, preventing offset or jamming during sliding of the universal joint outer ring 27, ensuring a stable flapping trajectory and improving power transmission efficiency.

[0060] The multi-layered structure of the universal joint, in conjunction with the crank 82 and connecting rod 86 of the flapping wing drive mechanism 8, ensures the smooth transmission of flapping motion. At the same time, the rotation function of the universal flapping frame 26, in conjunction with the universal joint structure, enables the synchronous adjustment of the angle of attack and the flapping motion, ensuring flight continuity and improving the response speed of attitude control.

[0061] The root of the flapping wing is a square shaft structure, which is inserted into the square through hole in the inner ring 21 of the universal joint and can slide relative to it; the flapping wing forms a spherical joint hinge with the ball head support fixed on the fuselage 3 through the hemispherical recess at the root.

[0062] During the flapping motion, the inner ring 21 of the universal joint drives the square shaft to move up and down. Since the square shaft and the square through hole have a square fit, relative rotation between them is avoided, ensuring that the movement of the inner ring 21 of the universal joint is fully transmitted to the flapping wing. During the angle of attack adjustment motion, the inner ring 21 of the universal joint drives the square shaft to rotate. The square fit ensures that the flapping wing rotates synchronously with the inner ring 21 of the universal joint, changing the angle of attack. At the same time, the spherical joint hinge allows the flapping wing to rotate flexibly around the ball head support, providing support for the multi-angle movement of the flapping wing and avoiding motion interference.

[0063] The inner ring 21 of the universal joint drives the flapping wing to rotate and adjust its angle through a square fit, and supports the flapping wing's flapping motion through a spherical joint hinge. The combination of the two makes the flapping wing's motion both precise and flexible, further improving the aircraft's maneuverability and control precision.

[0064] The universal flapping mechanism 2 is rotatably mounted on a circular platform on the side wall of the fuselage 3 through the shaft hole structure on the universal flapping frame 26; each universal flapping mechanism 2 is connected to a flapping wing rotation servo 35; a drive gear is fixed on the output shaft of the flapping wing rotation servo 35, and a driven gear ring is fixed on the universal flapping frame 26, and the drive gear and the driven gear ring mesh with each other.

[0065] When the angle of attack of a flapping wing needs to be adjusted, the corresponding flapping wing rotation servo 35 operates, driving the drive gear on its output shaft to rotate. The drive gear meshes with the driven gear ring, driving the driven gear ring and the universal flapping frame 26 to rotate around the frustum of the fuselage 3. When the universal flapping frame 26 rotates, it engages with the rectangular groove of the universal joint outer ring 27 through the rectangular step on its inner side, driving the universal joint outer ring 27, universal joint middle ring 23, universal joint inner ring 21 and flapping wing to rotate synchronously, thereby changing the angle of attack of the flapping wing. Since each flapping wing corresponds to an independent flapping wing rotation servo 35, the rotation angle of each universal flapping mechanism 2 can be controlled individually, realizing the independent adjustment of the angle of attack of the four flapping wings.

[0066] This structure works synergistically with the universal joint structure and the flapping wing mating structure: the gear transmission controls the rotation of the universal flapping frame 26, the universal joint structure transmits the rotational motion to the flapping wings, and the square mating ensures that the flapping wings rotate synchronously. The combination of the three achieves precise and independent adjustment of the angle of attack. At the same time, the independence of the gear transmission complements the centralized power transmission of the flapping wing drive mechanism 8, which not only ensures the transmission of flapping power but also achieves independent control of the angle of attack, taking into account both lightweight and high mobility.

[0067] The rotation range of the omnidirectional flapping mechanism 2 is limited to two extreme positions with a rotation angle of 90 degrees. When the omnidirectional flapping mechanism 2 is in the extreme position, the wing surface of the corresponding flapping wing is in a horizontal or vertical state.

[0068] When the flapping wing rotation servo 35 drives the omnidirectional flapping mechanism 2 to rotate, when it reaches its limit position, the limiting structure will prevent the omnidirectional flapping frame 26 from continuing to rotate, or the servo will trigger the travel protection to stop operation, ensuring that the rotation angle does not exceed 90 degrees. The horizontal wing surface corresponds to an angle of attack of about 0 degrees, and the wing surface is parallel to the airflow direction. At this time, the lift generated by the flapping wing is small and the thrust is large, which is suitable for rapid forward flight. The vertical wing surface corresponds to an angle of attack of about 90 degrees. The wing surface is perpendicular to the airflow direction. At this time, the lift generated by the flapping wing is large and the thrust is small, which is suitable for hovering or emergency stop.

[0069] The 90-degree rotation range covers the angle of attack range required for the flapping wing to operate effectively. This avoids both excessively small angles of attack that prevent the flapping wing from generating effective lift and excessively large angles of attack that could lead to airflow separation, a sudden drop in lift, or even stall. This ensures that the aircraft can stably generate lift or thrust under different flight conditions. The extreme positions correspond to horizontal and vertical wing attitudes, facilitating the aircraft control system to calibrate and precisely control the angle of attack. For example, when hovering, the flapping wing can be directly adjusted to a near-horizontal attitude, quickly responding to flight requirements and improving control efficiency.

[0070] like Figure 6 As shown, the machine body also includes a tail section 6, which includes a rear base fixed to the rear end of the body 3, multiple elastic tail rods 63, a counterweight slider 62 slidably sleeved on the tail rods 63, and a front base connected to the front end of the tail rods 63; the counterweight slider 62 is provided with through holes corresponding to the number of tail rods 63, and the tail rods 63 pass through the through holes.

[0071] According to the changes in flight attitude, the counterweight slider 62 can slide along the tail rod 63 to change the weight distribution of the tail 6, thereby adjusting the center of gravity of the whole aircraft so that the center of gravity always falls within the stable range of the fuselage 3. After the vibration generated by the flapping motion of the fuselage 3 is transmitted to the tail 6, the elastic tail rod 63 will undergo slight deformation to absorb some of the vibration energy and reduce the transmission of vibration to the counterweight slider 62 and other parts of the tail 6.

[0072] The sliding adjustment of the counterweight slider 62 solves the problem of center of gravity shift caused by changes in flight attitude, improving the aircraft's adaptability to complex attitudes. Secondly, the buffering effect of the elastic tail stick 63 reduces the vibration of the tail 6, and also reduces the reverse vibration transmission of the tail 6 to the fuselage 3, improving the overall flight stability of the aircraft.

[0073] like Figure 2As shown, the fuselage 3 includes: a flapping wing ball joint support 31, a fuselage frame 32, a worm gear fixing plate 33, a flapping wing rotation drive gear 34, and a flapping wing rotation servo 35; the structure of the fuselage 3 is symmetrical about its middle plane; the fuselage frame 32 has a frustum at the front and rear of each of its left and right side walls, which cooperates with the universal flapping mechanism 2, allowing the universal flapping mechanism 2 to rotate on the fuselage frame 32; the fuselage frame 32 has a pair of lifting lugs at the front and rear bottom; the fuselage frame 32 has two cantilever beams at the top, front and rear, for fixing the flapping wing ball joint support 31; the flapping wing ball joint support 31... 1. Fixed below the cantilever beam of the fuselage frame 32 to provide support for the flapping wing. The ball joints of the two flapping wing ball joint supports 31 fixed at the front of the fuselage frame 32 face forward, and the ball joints of the two flapping wing ball joint supports 31 fixed at the rear of the fuselage frame 32 face backward. Two worm gear fixing plates 33 are arranged at the front and rear ends of the lower part of the fuselage frame 32. The two ends of the worm gear fixing plates 33 are fixed to the two side walls of the fuselage frame 32. The worm gear fixing plates 33 have a hole in the middle to cooperate with the worm 85 in the flapping wing drive mechanism 8. The flapping wing rotation servo 35 is fixed to the two side walls below the cantilever beam of the fuselage frame 32. The flapping wing rotation servo 35 is arranged symmetrically with respect to the middle surface of the fuselage frame 32. Two flapping wing rotation servos 35 are installed at the front and two at the rear of the fuselage frame 32. The output shaft of the flapping wing rotation servo 35 extends through the openings on the two side walls of the fuselage frame 32. The flapping wing rotation drive gear 34 is fixed to the output shaft of the four flapping wing rotation servos 35.

[0074] like Figure 3 As shown, the flapping wing drive mechanism 8 includes: a dual-output shaft motor 81, a crank 82, a worm gear shaft 83, a worm gear 84, a worm 85, a connecting rod 86, and a transmission shaft 87; the dual-output shaft motor 81 is fixed inside the fuselage frame 32, with one output shaft pointing towards the front of the fuselage frame 32 and the other output shaft pointing towards the rear of the fuselage frame 32; one end of the transmission shaft 87 is connected to the output shaft of the dual-output shaft motor 81, and the other end is connected to the worm 85; both ends of the worm 85 pass through the worm shaft. The circular hole on the fixing plate 33 is then fixed to the machine frame 32; the worm gear 84 meshes with the worm 85 and is installed below the worm 85; the worm gear shaft 83 passes through the lifting lug hole below the machine frame 32 and the center hole of the worm gear 84, fixing the worm gear 84 below the machine frame 32; the crank 82 is fixed to both ends of the worm gear shaft 83 and rotates with the worm gear shaft 83; one end of the connecting rod 86 is hinged to the protruding shaft of the crank 82, and the other end cooperates with the universal flapping mechanism 2.

[0075] The flapping wing drive mechanism 8 is symmetrical about the front and rear of the dual-output shaft motor 81. The rotational motion output from the front and rear ends of the dual-output shaft motor 81 is transmitted to the front and rear worm gears 85 via two drive shafts 87 connected to its two ends. The front and rear worm gears 85 mesh with the front and rear worm wheels 84 respectively. The front and rear worm wheels 84 are connected to the front and rear worm wheel shafts 83 by keys. Each worm wheel shaft 83 has two cranks 82 fixed at both ends. There are a total of four cranks 82, each hinged to a connecting rod 86. The four connecting rods 86 drive the four universal flapping mechanisms 2 on the fuselage frame 32. Two cranks 82 are symmetrically installed about the fuselage 3 to ensure that the movement of the left front flapping wing 1 and the right front flapping wing 4 is symmetrical about the fuselage 3. Two cranks 82 located at the rear end of the fuselage frame 32 are symmetrically installed about the fuselage 3 to ensure that the movement of the left rear flapping wing 7 and the right rear flapping wing 5 is symmetrical about the fuselage 3. The installation angles of the two cranks 82 located at the front end of the fuselage frame 32 and the two cranks 82 located at the rear end of the fuselage frame 32 differ by 180 degrees. That is, when the two cranks 82 at the front end point upward, the two cranks 82 at the rear end point downward, so that there is a half-cycle phase difference in the flapping motion of the two pairs of flapping wings.

[0076] like Figure 2 , Figure 3 As shown, the rotational motion output by the dual-output shaft motor 81 installed in the middle of the frame 32 drives the worm 85 to rotate via the transmission shaft 87. The rotational motion of the worm 85 is transmitted to the worm wheel 84 meshing with it, resulting in a decrease in speed and an increase in torque. The worm wheel 84 drives the worm wheel shaft 83 and the cranks 82 installed at both ends of the worm wheel shaft 83 to rotate together. The rotational motion of the crank 82 is transmitted to the connecting rod 86 hinged to the cam shaft of the crank 82. The connecting rod 86 is hinged to the universal joint outer ring 27, causing the universal joint outer ring 27 to slide within the universal joint frame 26. That is, the crank 82, the connecting rod 86, and the universal joint outer ring 27 together form a crank-slider mechanism.

[0077] like Figure 1 As shown, the installation angles of the two cranks 82 at the front end of the fuselage frame 32 and the two cranks 82 at the rear end of the fuselage frame 32 differ by 180 degrees. That is, when the two cranks 82 at the front end point upward, the two cranks 82 at the rear end point downward. This results in a half-cycle phase difference between the flapping motions of the two pairs of flapping wings. When the two flapping wings at the front end flap upward, the two flapping wings at the rear end flap downward. While generating lift and thrust, the two pairs of flapping wings can balance some of the unbalanced forces on the aircraft body and reduce the vibration of the aircraft body.

[0078] like Figure 4 , Figure 5As shown, the universal flapping mechanism 2 includes: a universal joint inner ring 21, an inner ring shaft 22, a universal joint middle ring 23, a middle ring shaft 24, a flapping wing rotation driven gear ring 25, a universal flapping frame 26, and a universal joint outer ring 27. The universal joint inner ring 21 is cylindrical in shape with a square through hole in the middle, which can be fitted onto the root of the flapping wing. The universal joint inner ring 21 has a circular through hole at the top and bottom, respectively cooperating with the inner ring shaft 22. The inner ring shaft 22 has two parts, one at the top and one at the bottom; one end is inserted into the universal joint inner ring 21, and the other... The universal joint inner ring 21 is inserted into the universal joint middle ring 23, allowing it to rotate within the universal joint middle ring 23 about the axis of the inner ring shaft 22. The universal joint middle ring 23 has a circular through hole at its top, bottom, left, and right positions, with adjacent holes forming a 90-degree angle. The top and bottom holes mate with the inner ring shaft 22, and the left and right holes mate with the middle ring shaft 24. The middle ring shaft 24 has two ends, left and right, with one end inserted into the universal joint middle ring 23 and the other end inserted into the universal joint outer ring 27, allowing the universal joint middle ring 23 to rotate within the universal joint middle ring 23. The universal joint outer ring 27 can rotate around the axis of the central ring shaft 24 as its rotation center; the flapping wing driven gear ring 25 is fixed on the protruding circular ring structure at the rear of the universal flapping frame 26, and the outer ring gear teeth mesh with the flapping wing rotating drive gear 34; the universal flapping frame 26 is a rectangular frame with a protruding circular boss at the rear, and rectangular steps protruding from the frame on the inner sides of the two vertical long sides of the rectangular frame, which serve as slide rails for the universal joint outer ring 27 to slide within the universal flapping frame 26; the inner walls of the universal joint outer ring 27 are on the left and right sides respectively. A circular through hole is provided, which cooperates with two middle ring rotating shafts 24; a rectangular groove is provided on the left and right protruding parts of the outer side of the universal joint outer ring 27, which cooperates with the rectangular step on the inner side of the universal flapping frame 26, so that the universal joint outer ring 27 can slide in a straight line within the universal flapping frame 26; a protruding shaft is provided on the right side of the universal joint outer ring 27, which is hinged to the connecting rod 86. The motion output by the flapping wing drive mechanism 8 is transmitted to the universal joint outer ring 27 through this shaft, driving the universal joint outer ring 27 to perform reciprocating linear motion within the universal flapping frame 26.

[0079] The inner ring 21 of the universal joint is installed inside the middle ring 23 of the universal joint via two upper and lower inner ring shafts 22, and the inner ring 21 and the middle ring 23 of the universal joint can rotate relative to each other; the middle ring 23 of the universal joint is installed inside the outer ring 27 of the universal joint via two left and right middle ring shafts 24, and the middle ring 23 and the outer ring 27 of the universal joint can rotate relative to each other; the inner ring 21, the middle ring 23 of the universal joint, and the shafts together form a universal joint, and the components mating on the inner ring 21 of the universal joint can rotate simultaneously around two mutually perpendicular axes; after the root of the flapping wing mates with the square hole on the inner ring 21 of the universal joint, the flapping wing can slide in the square hole and also swing up and down and left and right.

[0080] like Figure 3 , Figure 4As shown, when the outer ring 27 of the universal joint slides within the universal flapping frame 26, it will drive the middle ring 23 and the inner ring 21 of the universal joint to move together. The square shaft at the root of the left front flapping wing 1 tends to slide relative to the square hole in the outer ring 27 of the universal joint. At this time, since the root of the left front flapping wing 1 is hinged to the flapping wing ball joint support 31 through a spherical joint, the left front flapping wing 1 is like a rocking oar, being rocked up and down by the outer ring 27 of the universal joint with the spherical joint as the fulcrum, that is, a flapping motion. The fuselage 3 has a symmetrical structure, and the four universal flapping mechanisms 2 are symmetrically arranged on it. The flapping wing drive mechanism 8 is also symmetrically arranged. The flapping principle and law of the remaining three flapping wings, except for the left front flapping wing 1, are the same as those of the left front flapping wing 1.

[0081] Driven by the flapping wing rotation drive gear 34, the universal flapping mechanism 2 can rotate around the center of the frustum on the side wall of the frame 32. The angle between the two extreme positions of the universal flapping mechanism 2 during rotation is 90 degrees. When the universal flapping mechanism 2 is in the two extreme positions, the flapping wing surface it cooperates with is in a horizontal or vertical state respectively. In the plane perpendicular to the rotation axis of the universal flapping mechanism 2, the worm gear shaft 83 is located on the angle bisector of the angle between the two extreme positions of the universal flapping mechanism 2, that is, the angle between it and the flapping wing surface in the horizontal or vertical state is 45 degrees. Under this positional relationship, the worm gear shaft 83 and the universal flapping mechanism 2 can ensure that when the motion output by the flapping wing drive mechanism 8 is driven by the universal flapping mechanism 2 to flap, the motion between the parts can always be transmitted no matter which position the universal flapping mechanism 2 rotates to, and the motion of the moving parts in the universal flapping mechanism 2 is always symmetrical about the angle bisector of the angle between the extreme positions.

[0082] like Figure 5 As shown, the left front flapping wing 1 has a hemispherical recessed structure near its root, which cooperates with the ball head of the flapping wing ball head support 31 to form a spherical pair; the root of the left front flapping wing 1 is a shaft-shaped structure with a square cross-section. After being inserted into the square hole in the center of the universal joint inner ring 21, the root of the left front flapping wing 1 can slide relative to the universal joint inner ring 21; the wing surface of the left front flapping wing 1 is made of wing veins and a thin film covering them.

[0083] The left front flapper 1 forms a spherical pair with the ball head of the flapper ball head support 31 at its root, and the flapper can rotate in space with the ball head as the rotation center; the left front flapper 1 and the left rear flapper 7 have the same structure, and the right front flapper 4 and the right rear flapper 5 have the same structure; the cooperation between the right front flapper 4, the right rear flapper 5, the left rear flapper 7 and the universal joint inner ring 21 and the flapper ball head support 31 is the same as the cooperation between the left front flapper 1 and the universal joint inner ring 21.

[0084] like Figure 6As shown, the tail section 6 includes: a rear tail base 61, a counterweight slider 62, tail rods 63, and a front tail base 64; one end of the rear tail base 61 is fixed to the rear end face of the body frame 32, and the other end is connected to four tail rods 63; the rear tail base 61 is fixed to the tail of the four tail rods 63; the tail rods 63 are cylindrical long rods with a certain degree of elasticity; the counterweight slider 62 is designed with four circular through holes around its perimeter, and the four circular through holes pass through the four tail rods 63 respectively, so that the counterweight slider 62 can only slide along the axial direction of the tail rods 63.

[0085] Example 2

[0086] This embodiment provides a flight method for a dragonfly-like flapping-wing aircraft as described above, including: simultaneously driving four flapping wings to perform synchronized reciprocating flapping motions via a drive motor; controlling the rotation angle of four omnidirectional flapping mechanisms 2 via four independent flapping-wing rotation servos 35, thereby independently adjusting the angle of attack of each flapping wing; when it is necessary to change the flight attitude, controlling the angle of attack of at least one flapping wing to change relative to the other flapping wings, causing the lift or drag generated on both sides or in front and behind the aircraft to become unbalanced, thereby generating a torque that causes the aircraft to yaw, roll, or pitch; and maintaining a 180-degree phase difference between the flapping motions of the front pair of flapping wings and the rear pair of flapping wings to counteract the unbalanced forces generated during the flapping process and reduce the vibration of the aircraft.

[0087] A single drive motor simultaneously drives four flapping wings to perform synchronized reciprocating flapping motions, providing the aircraft with basic lift and thrust. During the continuous flapping motion, four independent flapping wing rotation servos 35 control the rotation angle of the four omnidirectional flapping mechanisms 2, thereby independently adjusting the angle of attack of each flapping wing and achieving precise control over the motion state of a single flapping wing. When it is necessary to change the flight attitude, the angle of attack of at least one flapping wing is changed relative to the other flapping wings, so that the lift or drag generated by that flapping wing differs from that of the other flapping wings, thereby generating torque on both sides or in the front and rear directions of the fuselage 3, pushing the fuselage 3 to adjust its attitude. During the flapping process, the flapping motion of the front pair of flapping wings is controlled to maintain a 180-degree phase difference with the flapping motion of the rear pair of flapping wings to counteract the unbalanced force generated by the flapping and reduce the vibration of the aircraft.

[0088] The use of a single drive motor to power four flapping wings replaces the existing multi-motor drive method, reducing drive energy consumption, lowering overall operating costs, and simplifying power control logic. The four servos independently adjust the angle of attack, allowing each flapping wing to be individually adjusted, improving attitude control flexibility. The aircraft can achieve various complex attitudes through differentiated angles of attack; for example, increasing the angle of attack of the left flapping wing while keeping the right flapping wing's angle of attack constant generates a rightward roll moment, achieving roll; increasing the angle of attack of the left forward flapping wing 1 while keeping the other flapping wings constant generates a yaw moment, achieving yaw. The phase difference between the front and rear wings effectively reduces unbalanced forces, improving flight stability, while also reducing vibration-induced wear on components and extending the aircraft's continuous operating time.

[0089] like Figure 7 , Figure 8 , Figure 9 , Figure 10 , Figure 11 , Figure 12 As shown, the universal flapping mechanism 2, driven by the flapping wing rotation drive gear 34, can rotate around the center of the frustum on the side wall of the fuselage frame 32. The angle between the two extreme positions of the universal flapping mechanism 2 during rotation is 90 degrees. When the universal flapping mechanism 2 is in the two extreme positions, the corresponding flapping wing surfaces are in a horizontal or vertical state, respectively. That is, the angle of attack of the flapping wing can be adjusted between 0 and 90 degrees. Since the rotation of each universal flapping mechanism 2 is driven by a corresponding unique flapping wing rotation servo 35, the changes in the angle of attack of the four flapping wings are independent of each other. At the same time, in the universal flapping mechanism 2, since the universal joint outer ring 27 can slide within the universal flapping frame 26, when the flapping wing rotation servo 35 drives the universal flapping mechanism 2 to rotate during flapping, the universal joint outer ring 27 and other parts on it will not hinder or interfere with the rotation of the universal flapping mechanism 2. That is, the angle of attack of the flapping wing can be freely adjusted during flapping.

[0090] like Figure 13 As shown, when the left front flapping wing 1 increases the angle of attack of the flapping wing, the other three flapping wings continue to flap up and down. At this time, the forces on the left and right sides of the aircraft are no longer balanced, generating a yaw torque, causing the aircraft to yaw and achieve a turn.

[0091] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A flapping-wing aircraft with adjustable angle of attack, mimicking a dragonfly flapping wing, characterized in that, This includes the airframe, flapping wing assembly, omnidirectional flapping mechanism, and flapping wing drive mechanism; The aircraft body includes a fuselage, and the flapping wing assembly, the omnidirectional flapping mechanism and the flapping wing drive mechanism are all mounted on the fuselage; The flapping wing assembly includes four flapping wings, and the omnidirectional flapping mechanism has four flapping wings, each connected to one of the flapping wings in turn; The flapping wing drive mechanism is connected to the omnidirectional flapping mechanism and drives the flapping wings to perform flapping motion; The omnidirectional flapping mechanism can independently adjust the angle of attack of the corresponding flapping wing; The flapping wing drive mechanism includes a dual-output shaft motor, a drive shaft, a worm, a worm wheel, a worm wheel shaft, a crank, and a connecting rod. The front and rear output shafts of the dual-output shaft motor are respectively connected to the front and rear worms via the drive shaft. Each worm meshes with a worm wheel, and each worm wheel is fixed to a worm wheel shaft. Each end of each worm wheel shaft is provided with a crank. Each crank is hinged to a universal flapping mechanism via a connecting rod. The universal joint flapping mechanism includes an inner universal joint ring, a middle universal joint ring, an outer universal joint ring, and a universal joint flapping frame; the inner universal joint ring is installed inside the middle universal joint ring via two upper and lower inner ring pivots; the middle universal joint ring is installed inside the outer universal joint ring via two left and right middle ring pivots; the outer universal joint ring is slidably disposed within the universal joint flapping frame; The universal flapping mechanism is rotatably mounted on a circular platform on the side wall of the fuselage through a shaft hole structure on the universal flapping frame; each universal flapping mechanism is connected to a flapping wing rotation servo; a drive gear is fixed on the output shaft of the flapping wing rotation servo, and a driven gear ring is fixed on the universal flapping frame, with the drive gear and the driven gear ring meshing with each other.

2. The flapping-wing angle-adjustable dragonfly-like flapping-wing aircraft as described in claim 1, characterized in that, The flapping wing assembly includes a left front flapping wing, a right front flapping wing, a right rear flapping wing, and a left rear flapping wing. The left front flapping wing and the right front flapping wing are symmetrically installed on the front of both sides of the fuselage, and the left rear flapping wing and the right rear flapping wing are symmetrically installed on the rear of both sides of the fuselage.

3. The flapping-wing angle-adjustable dragonfly-like flapping-wing aircraft as described in claim 1, characterized in that, The two cranks on the front worm gear shaft and the two cranks on the rear worm gear shaft are installed at an angle 180 degrees apart, which makes the flapping motion of the front and rear pairs of flapping wings have a phase difference of half a cycle.

4. The flapping-wing angle-adjustable dragonfly-like flapping-wing aircraft as described in claim 1, characterized in that, The root of the flapping wing is a square shaft structure, which is inserted into the square through hole in the inner ring of the universal joint and can slide relative to it; the flapping wing is connected to the ball head support fixed to the fuselage through the hemispherical recess at the root to form a spherical joint hinge.

5. The flapping-wing angle-adjustable dragonfly-like flapping-wing aircraft as described in claim 1, characterized in that, The rotation range of the omnidirectional flapping mechanism is limited to two extreme positions with a rotation angle of 90 degrees. When the omnidirectional flapping mechanism is in the extreme position, the wing surface of the corresponding flapping wing is in a horizontal or vertical state.

6. The flapping-wing angle-of-attack adjustable dragonfly flapping-wing aircraft as described in claim 1, characterized in that, The machine body also includes a tail section, which includes a rear base fixed to the rear end of the machine body, multiple elastic tail rods, a counterweight slider slidably fitted on the tail rods, and a front base connected to the front end of the tail rods; the counterweight slider is provided with through holes corresponding to the number of tail rods, and the tail rods pass through the through holes.

7. A flight method for a flapping-wing, angle-of-attack adjustable dragonfly-like flapping-wing aircraft as described in any one of claims 1-6, characterized in that, include: A single drive motor simultaneously drives four flapping wings to perform synchronized reciprocating flapping motions. The rotation angle of each of the four omnidirectional flapping mechanisms is controlled by four independent flapping wing rotation servos, thereby independently adjusting the angle of attack of each flapping wing; When it is necessary to change the flight attitude, the angle of attack of at least one flapping wing is changed relative to the other flapping wings, causing the lift or drag generated on both sides or in front and behind the aircraft to become unbalanced, thereby generating a moment that causes the aircraft to yaw, roll or pitch. By controlling the flapping motion of the front pair of flapping wings and the rear pair of flapping wings to maintain a 180-degree phase difference, the unbalanced force generated during the flapping process can be counteracted, thereby reducing the vibration of the aircraft.

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