Flapping-wing air vehicle capable of hovering based on rotating structure and control method of flapping-wing air vehicle

Abstract

The invention relates to a flapping-wing air vehicle capable of hovering based on a rotating structure and a control method thereof. The aircraft comprises a fuselage, a wing assembly I and a wing assembly II, each of the wing assembly I and the wing assembly II comprises two wings; a steering engine steering mechanism, a first flapping mechanism and a second flapping mechanism are mounted on the fuselage; the first flapping mechanism is connected with two wings in the first wing assembly, and the second flapping mechanism is connected with two wings in the second wing assembly. Omni-directional flight motion control is achieved by rotating the machine body through the steering engine and by means of differential speed of the flapping mechanisms on the two sides. According to the aircraft, a pair of symmetrically-arranged flapping mechanisms and a pair of wing assemblies are designed and connected through a fuselage provided with a steering engine steering mechanism, and the speed of motors in the flapping mechanisms is adjusted, so that the aircraft can be kept hovering or fly towards one side. The steering engine mounted on the fuselage rotates to drive the central connecting rod, so that flight motion control in any direction can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to a flapping-wing aircraft capable of hovering based on a rotating structure and a control method thereof. Background Art

[0002] Micro air vehicles have outstanding advantages such as miniaturization, high maneuverability, high concealment, and flexible deployment. They can perform key tasks such as covert approach and special reconnaissance in complex environments. The micro air vehicles currently under development and in use mainly include micro fixed-wing aircraft, micro rotorcraft and micro flapping-wing aircraft. Compared with rotorcraft and fixed-wing aircraft, flapping-wing aircraft have excellent concealment performance and maintain high aerodynamic efficiency in small-scale low Reynolds number environments.

[0003] Bionic flapping-wing aircraft can be divided into two categories: control surface control and wing modulation control. For wing modulation control, the current mainstream control method is to modulate the wing shape and wing motion trajectory to achieve attitude control. Currently, this type of mechanism design often uses three servos or two servos plus two motors to modulate the wing to achieve three-degree-of-freedom attitude control. However, this type of mechanism design has the disadvantages of being difficult to lighten and miniaturize, and complex to control due to the complex mechanical structure and control quantity coupling.

[0004] At present, the common flapping-wing aircraft mechanism design mainly controls the left and right wing airfoils or motion trajectories through three servo actuators to achieve attitude control. This type of mechanical structure is relatively complex, which is not conducive to lightweight and miniaturization. In addition, multiple actuators finely control the changes in wing shape, resulting in strong coupling of attitude torque control and great control difficulty.

[0005] Therefore, there is a need to realize a hovering flapping-wing aircraft and a control method thereof that improves control accuracy and reduces flight control difficulty. Summary of the invention

[0006] In order to solve the deficiencies in the prior art, an object of the present invention is to provide a hovering flapping-wing aircraft based on a rotating structure and a control method thereof.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A hovering flapping-wing aircraft based on a rotating structure, the aircraft comprising: an aircraft body, a steering mechanism for a servo, a first flapping mechanism and a second flapping mechanism; the aircraft body comprises a fuselage and a wing assembly 1 and a wing assembly 2 respectively arranged on both sides of the fuselage; the wing assembly 1 and the wing assembly 2 each comprise two wings; the steering mechanism for a servo, the first flapping mechanism and the second flapping mechanism are all mounted on the fuselage; the first flapping mechanism is connected to the two wings in the wing assembly 1, and the second flapping mechanism is connected to the two wings in the wing assembly 2.

[0009] The servo steering mechanism is used to rotate the aircraft body, change the direction of the aircraft body, and cooperate with the differential of the two flapping mechanisms to achieve flight control of the aircraft in different directions; the first flapping mechanism is used to drive the two wings in the wing assembly one to produce flapping motion to provide lift and perform wing attitude control; the second flapping mechanism is used to drive the two wings in the wing assembly two to produce flapping motion, and cooperate with the first flapping mechanism to adjust the flapping differential of the wings on both sides of the fuselage to achieve balance and steering control of the aircraft.

[0010] Furthermore, the wing assembly one includes a first wing and a second wing; the wing assembly two includes a third wing and a fourth wing; the first wing, the second wing, the third wing and the fourth wing all include a wing surface and a connecting rod.

[0011] Furthermore, the fuselage includes a central connecting rod and a steering gear cantilever arranged in parallel, and a central frame located between the central connecting rod and the steering gear cantilever; two connecting rods are arranged between the central connecting rod and the second fixing part; a first central hole is opened in the middle of the central connecting rod, a first motor mounting hole and a second motor mounting hole are opened at both ends of the central connecting rod, and a first connecting rod fixing hole and a second connecting rod fixing hole are also opened on the central connecting rod; a second central hole is opened in the middle of the steering gear cantilever, and a third connecting rod fixing hole and a fourth connecting rod fixing hole are opened at both ends respectively.

[0012] Furthermore, the central frame includes a boss base, a support shaft installed on the top of the boss base, and a ball bearing connected to the support shaft; the ball bearing is installed in the first center hole; and the bottom of the boss base is provided with a first servo mounting hole and a second servo mounting hole.

[0013] Furthermore, the servo steering mechanism includes a servo; the servo includes a servo body, a servo motor shaft arranged on the servo body, and a first mounting portion and a second mounting portion arranged on both sides of the servo body; the servo motor shaft is installed in the second center hole; the first mounting portion and the first servo mounting hole are arranged correspondingly, and the second mounting portion and the second servo mounting hole are arranged correspondingly, for fixing the servo to the boss base.

[0014] Furthermore, the first flapping mechanism and the second flapping mechanism have the same structure, and both include a motor, a bracket and a gear crank transmission unit; the crank gear transmission unit includes a first gear, a double gear, a second gear, a third gear, a first crank and a second crank; the output shaft of the motor is connected to the first gear; the double gear includes an upper gear and a lower gear arranged on the same axis; the first gear is meshed and connected with the lower gear; the upper gear is meshed and connected with the second gear; the second gear is meshed and connected with the third gear; one end of the first crank is installed on the second gear, and one end of the second crank is installed on the third gear; the other end of the first crank is connected to the front end of the bracket, for driving the flapping of the first wing; the other end of the second crank is connected to the connection point at the rear of the bracket, for driving the flapping of the second wing; the symmetrical flapping of the wings is achieved through the coordinated movement of gear transmission and cranks.

[0015] Furthermore, the bracket includes a support frame; a central circular hole is provided in the middle of the support frame; a plurality of reinforcing ribs are provided between the outer periphery of the central circular hole and the inner wall of the support frame; a first cylindrical structure, a second cylindrical structure and a third cylindrical structure protruding upward are provided on the top of the support frame; the first cylindrical structure is connected to the second gear; the second cylindrical structure is connected to the third gear; the third cylindrical structure is connected to the double gear; a connecting hole is also provided on the top of the support frame, and a leading edge connecting piece is installed in the connecting hole; the leading edge connecting piece includes a first leading edge connecting piece and a second leading edge connecting piece; the extended end of the connecting rod is fixedly connected to the leading edge connecting piece of the flapping mechanism; the first leading edge connecting piece and the second leading edge connecting piece are respectively connected to the connecting rods in the two wings in the same side wing assembly.

[0016] The present invention also includes a method for controlling the above-mentioned flapping-wing aircraft capable of hovering based on a rotating structure, the method comprising the following steps:

[0017] S1. Start the aircraft

[0018] After the aircraft is started, the motors of the two flapping mechanisms start to run, driving their respective corresponding gear crank transmission units to operate, and the gear crank transmission units drive each wing to flap.

[0019] S2. Flutter control and posture adjustment

[0020] By controlling the rotation speed of the motors in the two flapping mechanisms, the left and right groups of wings can flap at a certain frequency; if the flapping frequency of the wings on the left and right sides of the fuselage is equal, the aircraft will generate upward lift; by adjusting the rotation speed of the motors in the two flapping mechanisms and utilizing the differential speed control of the motors in the two flapping mechanisms, the flapping frequency difference of the wings on the left and right sides of the fuselage can be changed to adjust the attitude of the aircraft.

[0021] S3, steering gear control

[0022] The servo controls the rotation angle of the aircraft through the servo motor shaft. The rotation of the servo motor shaft drives the entire fuselage to rotate around the yaw axis, allowing the aircraft to adjust its attitude in any direction to achieve the orientation control of the aircraft.

[0023] Furthermore, after the aircraft is started, the motors of the two flapping mechanisms start to operate, driving the corresponding gear crank transmission units to operate, and the gear crank transmission units drive each wing to flap, including:

[0024] The output shaft of the motor meshes with the first gear to transmit power to the double gears, and the double gears then transmit the power to the second gear and the third gear respectively, thereby achieving two-stage reduction; the second gear and the third gear respectively drive the first leading edge connecting member and the second leading edge connecting member to move through the first crank and the second crank, thereby driving each wing to flap.

[0025] The method of adjusting the rotation speed of the motors in the two flapping mechanisms and utilizing the differential speed control of the motors in the two flapping mechanisms to change the flapping frequency difference of the wings on the left and right sides of the fuselage to adjust the attitude of the aircraft includes:

[0026] By increasing the speed of the motor in the left flapping mechanism, the flapping frequency of the left wing is greater than that of the right wing, the lift generated by the left wing is greater than that of the right wing, and the aircraft rotates counterclockwise around its roll axis; by increasing the speed of the motor in the right flapping mechanism, the flapping frequency of the right wing is greater than that of the left wing, the lift generated by the right wing is greater than that of the left wing, and the aircraft rotates clockwise around its roll axis.

[0027] Furthermore, the method further comprises:

[0028] S4, lifting and hovering control

[0029] S41, hovering: when the motor speeds in the flapping mechanisms on the left and right sides are equal, the lift of the wings on the left and right sides cancel each other out, and the aircraft maintains balance. If the total lift of the aircraft is equal to the gravity at this time, the aircraft achieves a hovering state.

[0030] S42, ascending: the motors in the flapping mechanisms on the left and right sides are accelerated at the same time, the flapping frequency of the wings on both sides is increased, and the lift of the wings on both sides is increased. If the total lift of the aircraft is greater than the gravity at this time, the aircraft ascends;

[0031] S43, descending: reducing the rotation speed of the motors in the flapping mechanisms on the left and right sides, reducing the flapping frequency of the wings on both sides, and reducing the lift of the wings on both sides. If the total lift of the aircraft is less than the gravity of the aircraft at this time, the aircraft descends.

[0032] S5, three-axis attitude control

[0033] S51, Roll axis Roll control: By differentially controlling the left and right wings, the flapping frequency difference of the wings on both sides is changed to realize the rotation of the aircraft around the roll axis. If the frequency on the left side is faster, it will roll to the right, otherwise it will roll to the left.

[0034] S52, Pitch control: While the servo controls the yaw of the aircraft, the relative phase difference of the wing flapping is adjusted by controlling the speed of the motors in the flapping mechanisms on both sides to achieve attitude adjustment around the pitch axis.

[0035] S53, Yaw control: By rotating the servo shaft, the entire aircraft is driven to yaw around the vertical axis to adjust the flight direction.

[0036] S6. Periodic splitting control: During the flapping control of the aircraft, different torques are output by adjusting the flapping phase and frequency difference of the wings to achieve three-axis attitude control.

[0037] Compared with the prior art, the advantages of the present invention are:

[0038] (1) The present invention proposes a hovering flapping-wing aircraft based on a rotating structure and a control method thereof. The aircraft realizes all-round flight motion control by rotating the body of the aircraft with the help of the differential speed of the flapping mechanisms on both sides by means of the steering gear. The aircraft is designed with a pair of symmetrically arranged flapping mechanisms and a pair of wing assemblies, and is connected through a fuselage equipped with a steering gear steering mechanism. By adjusting the speed of the motor in the flapping mechanism, the aircraft can be kept hovering or flying to one side. By rotating the steering gear installed on the fuselage to drive the central connecting rod to change the direction of the aircraft, flight motion control in any direction can be achieved. The bionic flapping-wing aircraft breaks through the existing flapping-wing aircraft mechanism design of using a steering gear to directly change the direction of a single wing by using a steering gear, simplifies the structure of the aircraft, and better realizes lightweight. At the same time, after the input control amount is reduced, the coupling of the mechanical system is reduced, which is conducive to improving the system control accuracy, and provides a new idea for the mechanism design of bionic flapping-wing aircraft.

[0039] (2) The flapping-wing aircraft proposed in the present invention is a wing-modulated attitude control aircraft, which integrates multiple flight modes such as level flight, lift, and hovering, and has strong air retention and higher maneuverability. For the flight control of this type of aircraft, it is necessary to pursue lightweight and high precision. However, similar to the structure proposed in the present invention that realizes the attitude control of the roll axis by differential movement of the wings on both sides, two or more actuators are still required to realize the tilting of the tilt-flapping mechanism or the modulation of the wing airfoil to realize the three-dimensional change of the flapping plane and the wing change to achieve the three-axis attitude control target, and the control difficulty is still relatively large. In response to the above two problems, the present invention further improves the lightweight and miniaturization potential of the flapping-wing aircraft by reducing the number of end actuators of the existing mechanism and simplifying the control structure. In addition, a control method based on periodic splitting is proposed for the structure proposed in the present invention, which realizes the reduction of wing control from three-dimensional stereoscopic precision adjustment to two-dimensional flapping plane precision adjustment, simplifies the control method, and is conducive to reducing the coupling of three-axis control torque, improving control accuracy and reducing the difficulty of flight control. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the overall structure of the hovering flapping-wing aircraft based on the rotating structure in the present invention;

[0041] Figure 2-1 This is the structural diagram of the center frame. Figure 1 ;

[0042] Figure 2-2 This is the structural diagram 2 of the center frame;

[0043] FIG. 3 is a schematic diagram of the structure of the first flapping mechanism or the second flapping mechanism Figure 1 ;

[0044] Figure 3-2 is a second structural schematic diagram of the first flapping mechanism or the second flapping mechanism;

[0045] Figure 3-3 This is a schematic diagram of the structure of the gear crank transmission unit. Figure 1 ;

[0046] Figure 3-4 is a structural schematic diagram 2 of the gear crank transmission unit;

[0047] Figure 3-5 is a schematic diagram of the structure of the bracket;

[0048] Figure 4-1 It is a structural diagram of the steering mechanism of the servo;

[0049] Figure 4-2 It is a schematic diagram of the structure of the servo;

[0050] Figure 4-3 It is a schematic diagram of the structure of the servo cantilever;

[0051] Figure 5 It is a structural diagram of the center connecting rod;

[0052] Figure 6 It is a schematic diagram of the structure of the wing;

[0053] Figure 7-1 This is a schematic diagram of the principle of the wing generating rolling moment. Figure 1 ;

[0054] Figure 7-2 This is the second schematic diagram of the principle of the wing generating the rolling moment;

[0055] Figure 8 It is a schematic diagram of the principle of the servo controller controlling the steering of the frame.

[0056] in:

[0057] 1-1, central frame, 1-2, central connecting rod, 1-3a, first flapping mechanism, 1-3b, second flapping mechanism, 1-4a, first wing, 1-4b, second wing, 1-4c, third wing, 1-4d, fourth wing, 1-5, steering mechanism of servo, 2-1, boss base, 2-2, ball bearing, 2-3a, first servo mounting hole, 2-3b, second servo mounting hole, 3-1, motor, 3-2, bracket, 3-2-1, first cylindrical structure, 3-2-2, second cylindrical structure, 3-2-3, third cylindrical structure, 3-2-4, central circular hole, 3-2-5, connecting hole, 3-3, first gear, 3-4 , double gear, 3-5a, second gear, 3-5b, third gear, 3-6a, first crank, 3-6b, second crank, 3-7a, first leading edge connecting piece, 3-7b, second leading edge connecting piece, 4-1a, first mounting part, 4-1b, second mounting part, 4-2, servo motor shaft, 4-3, second center hole, 4-4a, third connecting rod fixing hole, 4-4b, fourth connecting rod fixing hole, 4-5, connecting rod, 5-1, first center hole, 5-2a, first connecting rod fixing hole, 5-2b, second connecting rod fixing hole, 5-3a, first motor mounting hole, 5-3b, second motor mounting hole, 6-1, wing surface, 6-2, connecting rod. DETAILED DESCRIPTION

[0058] The present invention will be further described below in conjunction with the accompanying drawings:

[0059] The present invention proposes a mechanism design that realizes all-round flight control of an aircraft by combining central servo steering with flapping-wing differential drive. The aircraft only needs one servo and two flapping mechanisms to complete the control of the flight direction. The input control quantity is the motor speed of the flapping mechanisms on both wings and the deflection angle of the central servo. The aircraft can complete actions such as lifting, hovering, and free turning. The simplified mechanism makes the aircraft lightweight and miniaturized. A control method based on periodic splitting is proposed for the structure proposed in the present invention, which realizes the reduction of wing control from three-dimensional precise adjustment to two-dimensional flapping plane precise adjustment, simplifies the control method, and is conducive to reducing the coupling of three-axis control torque, improving control accuracy, and reducing the difficulty of flight control.

[0060] like Figure 1 A hovering flapping-wing aircraft based on a rotating structure is shown, and the aircraft includes: an aircraft body, a steering mechanism 1-5, a first flapping mechanism 1-3a and a second flapping mechanism 1-3b; the aircraft body includes a fuselage and a wing assembly 1 and a wing assembly 2 respectively arranged on both sides of the fuselage; the wing assembly 1 and the wing assembly 2 each include two wings; the fuselage is equipped with a steering mechanism 1-5, a first flapping mechanism 1-3a and a second flapping mechanism 1-3b; the first flapping mechanism 1-3a is connected to the two wings in the wing assembly 1, and the second flapping mechanism 1-3b is connected to the two wings in the wing assembly 2. The steering mechanism 1-5 is used to adjust the overall direction by rotating the aircraft fuselage and control the yaw attitude of the aircraft. The first flapping mechanism 1-3a is used to drive the flapping of the first group of wings to generate lift and achieve attitude adjustment by speed regulation. The second flapping mechanism 1-3b is used to drive the flapping of the second set of wings, and cooperates with the first flapping mechanism to control the posture and flight direction through differential speed.

[0061] At present, the common flapping-wing aircraft mechanism design mainly realizes attitude control by controlling the airfoils or motion trajectories of the left and right wings through three servo actuators. This type of mechanical structure is relatively complex and is not conducive to lightweight and miniaturization. In addition, multiple actuators cause strong coupling of attitude torque control through fine control of wing shape changes, which makes control difficult. However, structures similar to the roll-axis attitude control realized by differential movement of the wings on both sides proposed in the present invention still require two or more actuators to realize the tilting of the tilt-flapping mechanism or the modulation of the wing airfoil to realize the three-dimensional change of the flapping plane and wing change to achieve the three-axis attitude control goal, and the control difficulty is still relatively large.

[0062] In order to solve the shortcomings brought by the above structural design, the present invention reduces the number of end actuators, adopts a centrally placed servo steering mechanism, simplifies the control mechanism, and improves the lightweight and miniaturization potential of flapping-wing aircraft. In view of the structure proposed by the present invention, a control method based on periodic splitting is proposed, that is, a 360-degree rotating flapping mechanism combined with a differential drive of flapping wings, thereby realizing the wing control from three-dimensional precise adjustment to two-dimensional flapping plane precise adjustment, achieving the effect of simplifying the control method, reducing the coupling of three-axis control torque, improving the control accuracy and reducing the difficulty of flight control. The mechanical structure of the flapping mechanism rotating in the lift plane is within the protection scope of the present invention; the control method of realizing periodic torque changes by 360-degree rotating flapping mechanism is within the protection scope of the present invention.

[0063] like Figure 1 As shown, the wing assembly 1 includes a first wing 1-4a and a second wing 1-4b; the wing assembly 2 includes a third wing 1-4c and a fourth wing 1-4d.

[0064] like Figure 1 As shown, the fuselage includes a central connecting rod 1-2 and a steering gear cantilever arranged in parallel, and a central frame 1-1 located between the central connecting rod 1-2 and the steering gear cantilever; two connecting rods 4-5 are arranged between the central connecting rod 1-2 and the second fixing part.

[0065] like Figure 5 As shown, the center of the central connecting rod 1-2 is provided with a first central hole 5-1, the two ends of the central connecting rod 1-2 are provided with a first motor mounting hole 5-3a and a second motor mounting hole 5-3b, and the central connecting rod 1-2 is also provided with a first connecting rod fixing hole 5-2a and a second connecting rod fixing hole 5-2b. Figure 4-3 As shown, a second central hole 4-3 is provided in the middle of the steering gear cantilever, and a third connecting rod fixing hole 4-4a and a fourth connecting rod fixing hole 4-4b are provided at both ends.

[0066] like Figure 2-1 and Figure 2-2 As shown, the central frame 1-1 includes a boss base 2-1, a support shaft installed on the top of the boss base 2-1, and a ball bearing 2-2 connected to the support shaft; the ball bearing 2-2 is installed in the first center hole 5-1 and has an interference fit with the first center hole 5-1; the bottom of the boss base 2-1 is provided with a first servo mounting hole 2-3a and a second servo mounting hole 2-3b.

[0067] like Figure 1 As shown, the steering mechanism 1-5 includes a steering gear. Figure 4-1~Figure 4-2As shown, the servo includes a servo body, a servo motor shaft 4-2 arranged on the servo body, and a first mounting portion 4-1a and a second mounting portion 4-1b arranged on both sides of the servo body; the servo motor shaft 4-2 is installed in the second center hole 4-3; the first mounting portion 4-1a and the first servo mounting hole 2-3a are arranged correspondingly, and the second mounting portion 4-1b and the second servo mounting hole 2-3b are arranged correspondingly, for fixing the servo on the boss base 2-1.

[0068] The present invention drives the yaw of the aircraft fuselage through the rotation of the servo, thereby adjusting the overall direction, and no longer requires complex single-sided wing adjustment. The servo simplifies the control method of the body steering and reduces the need for multiple actuators. The servo steering mechanism 1-5 controls the rotation of the fuselage. By adjusting the rotation angle of the central connecting rod, the fuselage rotates around the vertical axis (Yaw axis) to change the direction of the aircraft. Compared with the traditional single-sided wing adjustment, this control method based on the rotation of the servo is simpler and more direct, easy to operate, and reduces the number of actuators.

[0069] like Figure 3-1 to Figure 3-5 As shown, the first flapping mechanism 1-3a and the second flapping mechanism 1-3b have the same structure, both including a motor 3-1, a bracket 3-2 and a gear crank transmission unit; the crank gear transmission unit includes a first gear 3-3, a double gear 3-4, a second gear 3-5a, a third gear 3-5b, a first crank 3-6a and a second crank 3-6b; the output shaft of the motor 3-1 is connected to the first gear 3-3; the double gear 3-4 includes an upper gear and a lower gear arranged on the same axis; the first gear 3-3 is meshed and connected with the lower gear; the upper gear is meshed and connected with the second gear 3-5a; the second gear 3-5a is meshed and connected with the third gear 3-5b; one end of the first crank 3-6a is installed on the second gear 3-5a, and the other end is connected to the first front edge connecting member 3-7a. One end of the second crank 3-6b is installed on the third gear 3-5b, and the other end is connected to the second front edge connecting member 3-7b. The first crank 3-6a and the second crank 3-6b are respectively connected to the leading edge connector assembly on the bracket 3-2. Specifically, the other end of the first crank 3-6a is connected to the front end of the bracket 3-2 to drive the flapping of the first wing 1-4a; the other end of the second crank 3-6b is connected to the connection point at the rear of the bracket 3-2 to drive the flapping of the second wing 1-4b. The symmetrical flapping of the wings is achieved through the coordinated movement of the gear transmission and the cranks.

[0070] The present invention realizes the roll axis attitude control of the aircraft through the differential speed control of the motors in the flapping mechanisms of the wings on both sides. The difference in the rotation speed of the motors on both sides causes different flapping frequency differences, thereby adjusting the pitch, roll and yaw attitudes of the aircraft. The left and right wings are driven by their respective motors 3-1, and the differential control makes the wings on one side flap faster or slower, thereby affecting the roll and pitch attitudes of the aircraft. For example, when the flapping frequency of the left wing increases, the aircraft will roll to the right. By adjusting the frequency difference of the motors on both sides, the aircraft can achieve complex attitude adjustments in the air.

[0071] The main part of the bracket 3-2 is a triangular frame structure with good strength and rigidity; the triangular design helps to reduce weight while ensuring sufficient structural strength. The bracket 3-2 includes a support frame; a central circular hole 3-2-4 is provided in the middle of the support frame; a plurality of reinforcing ribs are provided between the outer periphery of the central circular hole 3-2-4 and the inner wall of the support frame; the top of the support frame is provided with an upwardly protruding first cylindrical structure 3-2-1, a second cylindrical structure 3-2-2 and a third cylindrical structure 3-2-3; the top of the support frame is also provided with a connecting hole 3-2-5, in which a leading edge connector is installed; the leading edge connector includes a first leading edge connector 3-7a and a second leading edge connector 3-7b. The central circular hole 3-2-4 is used to install the motor 3-1. This hole is located in the center of the bracket, which can well keep the motor aligned with other mechanical structures. This design ensures that the transmission mechanism (such as gears) and the crank can work stably and avoids unnecessary vibration caused by eccentricity. Figure 3-5 It can be seen that multiple reinforcing ribs extend from the central circular hole 3-2-4 of the bracket to the triangular edge of the bracket. These reinforcing ribs are designed to increase the overall strength of the bracket, avoid deformation when the motor runs at high speed, and reduce weight. This design optimizes the strength-to-weight ratio of the structure, making the bracket both light and stable. At the top of the bracket are a first circular column structure 3-2-1, a second cylindrical structure 3-2-2, and a third cylindrical structure 3-2-3, which are used to connect the bracket and the second gear 3-5a, the third gear 3-5b and the double gear 3-4. The connecting hole 3-2-5 is used to fix the first leading edge connector 3-7a and the second leading edge connector 3-7b, and the first leading edge connector 3-7a and the second leading edge connector 3-7b are aligned and fixed through the middle hole.

[0072] Through the above scheme, the motor provides power to rotate the first gear 3-3, and two-stage reduction is achieved through the double gear 3-4 and the second gear 3-5a. The second gear 3-5a drives the third gear 3-5b of the same size to rotate at the same speed. The second gear 3-5a drives the first leading edge connector 3-7a to move through the first crank 3-6a, thereby driving the corresponding wing to flap regularly. The third gear 3-5b drives the first leading edge connector 3-7a and the second leading edge connector 3-7b to achieve regular flapping through the second crank 3-6b. By controlling the speed difference of the motor 3-1, the frequency of flapping can be changed, thereby controlling the attitude of the aircraft such as lifting and rolling. When the aircraft needs to change direction, the steering gear receives the instruction through the control system and starts to drive the steering gear motor shaft to rotate. The rotation of the steering gear motor shaft drives the central connecting rod connected to it to rotate together. The rotation of the central connecting rod directly affects the rotation of the fuselage, especially when the aircraft yaws (Yaw), the fuselage rotates around its vertical axis. By controlling the rotation angle of the servo, the aircraft can accurately adjust its orientation and change its flight direction. While the servo rotates to change the direction of the fuselage, the flapping mechanisms on the left and right sides continue to flap, providing stable lift for the aircraft. The rotation of the servo does not affect the normal movement of the flapping, but by adjusting the rotation speed of the motors on both sides, the aircraft can achieve more complex attitude changes, such as turning, hovering and adjustment of the flight angle. The present invention controls the overall yaw of the aircraft through the servo, avoiding the problem of complex attitude adjustment. In traditional flapping-wing aircraft, the servo may need to change the direction of the wing through complex unilateral control to adjust the direction of the aircraft. The servo steering mechanism of the present invention achieves overall direction adjustment by rotating the fuselage, simplifying the control method of the flight direction. The simple rotation action of the servo reduces the need for attitude adjustment of a single wing, further reduces the control difficulty, and achieves the overall lightweight of the aircraft.

[0073] like Figure 6 As shown, the wing is composed of a wing surface 6-1 and a connecting rod 6-2, and is fixedly connected to the leading edge connecting member of the flapping mechanism through one end of the connecting rod 6-2. The two wings in the wing assembly 1 are respectively connected to the first leading edge connecting member and the second leading edge connecting member in the first flapping mechanism. The two wings in the wing assembly 2 are respectively connected to the first leading edge connecting member and the second leading edge connecting member in the second flapping mechanism.

[0074] The present invention also includes a method for controlling the above-mentioned flapping-wing aircraft capable of hovering based on a rotating structure.

[0075] The positive direction of the roll axis is defined as the direction from the center of the first center hole 5-1 perpendicular to the center axis of the center connecting rod 1-2 to the outside, and the positive direction of the yaw axis is the opposite direction of the gravity of the bionic aircraft; the positive direction of the pitch axis is from the center of the first center hole 5-1 to the center of the second connecting rod fixing hole 5-2b. The positive direction of the roll axis is forward, and the negative direction is backward; the positive direction of the pitch axis is right, and the negative direction is left; the positive direction of the yaw axis is up, and the negative direction is down.

[0076] The aerodynamic effects of the wings of the above-mentioned hovering flapping-wing aircraft based on the rotating structure include the start-up effect of the Roll axis and the aerodynamic effect of the Yaw axis. The two aerodynamic effects are specifically described as follows:

[0077] (1) Pneumatic effect of the roll shaft

[0078] When the wings in the first flapping mechanism 1-3a and the second flapping mechanism 1-3b produce asymmetric flapping (i.e., the flapping frequencies of the left and right wings are different), the aircraft will rotate around the roll axis. Specifically, when the flapping frequency of the first wing 1-4a and the second wing 1-4b on the left side is greater than that of the third wing 1-4c and the fourth wing 1-4d on the right side, the aircraft will roll counterclockwise (to the right) around the roll axis. When the flapping frequency of the right wing is greater than that of the left side, the aircraft will roll clockwise (to the left) around the roll axis.

[0079] (2) Aerodynamic effect of the yaw axis

[0080] When the steering mechanism 1-5 rotates the entire fuselage of the aircraft, the aircraft will yaw around the yaw axis. Specifically, when the steering mechanism rotates the fuselage to the left, the direction of the aircraft will rotate clockwise around the yaw axis, that is, turn right. When the steering mechanism rotates the fuselage to the right, the direction of the aircraft will rotate counterclockwise around the yaw axis, that is, turn left.

[0081] like Figure 7-1 and Figure 7-2 As shown, when the flapping frequency of the first wing 1-4a and the second wing 1-4b driven by the motor in the first flapping mechanism is greater than the flapping frequency of the third wing 1-4c and the fourth wing 1-4d, a counterclockwise rolling moment around the roll axis is generated, causing the aircraft to roll to the right; conversely, a clockwise rolling moment around the roll axis is generated, causing the aircraft to roll to the left.

[0082] like Figure 8 As shown, the servo actuator of the steering gear can control the steering of the entire frame and deflect a specified angle around the central axis.

[0083] In this embodiment, two input quantities are required to control the movement of the aircraft, one is the rotation angle of the steering gear servo actuator, and the other is the speed of the motors in the flapping mechanisms on both sides. When the motors on both sides control the same speed, the rolling moments brought by the flapping of the wings on both sides cancel each other out, generating an upward lift. When the upward lift is equal to the sum of the drag and gravity, the aircraft hovers. When the motor speed increases, the flapping frequency increases, and the lift generated by it increases to a value greater than the sum of the drag and gravity, and the aircraft will fly upward. On the contrary, when the motor speed decreases, when the overall lift is less than the gravity, the aircraft will fall downward. The speeds of the motors on both sides are controlled differently, and different rolling moments are generated on both sides, causing the aircraft to produce a posture change that is biased to one side, and the yaw moment is achieved by the rotation angle of the steering gear. When the steering gear rotates, it drives the fuselage to rotate around the vertical yaw axis, thereby changing the direction of the aircraft. When the steering gear rotates the fuselage clockwise, the aircraft will yaw to the right. When the steering gear rotates the fuselage counterclockwise, the aircraft will yaw to the left. Combined with the steering of the entire aircraft frame, the aircraft can achieve 360-degree yaw motion control and has the functions of lifting, descending and hovering.

[0084] The control method of the above-mentioned flapping-wing aircraft capable of hovering based on a rotating structure comprises the following steps:

[0085] S1. Start the aircraft

[0086] After the aircraft is started, the motors 3-1 of the two flapping mechanisms start to operate, driving their corresponding gear transmission systems. The motor output shaft meshes with the first gear 3-3, transmitting power to the double gear 3-4, and then the double gear transmits the power to the second gear 3-5a and the third gear 3-5b respectively, thereby achieving two-stage reduction. The second gear 3-5a and the third gear 3-5b drive the first leading edge connector 3-7a and the second leading edge connector 3-7b of the wing through the first crank 3-6a and the second crank 3-6b respectively, causing the wing to perform flapping motion.

[0087] S2. Flutter control and posture adjustment

[0088] The flapping mechanism controls the speed of the motor to make the left and right wings flap at a certain frequency. When the flapping frequencies on both sides are equal, the aircraft generates upward lift. When the attitude of the aircraft needs to be adjusted, the differential control of the flapping mechanisms on the left and right sides is used, that is, by adjusting the speed of the motors on both sides, the difference in the flapping frequencies of the left and right wings is changed: increasing the speed of the left motor, that is, the flapping frequency of the left wing is faster, which will generate greater lift, thereby causing the aircraft to turn right (counterclockwise) around its roll axis. Increasing the speed of the right motor will increase the lift of the right wing, causing the aircraft to turn left (clockwise) around its roll axis.

[0089] S3, servo control and omnidirectional flight

[0090] The servo steering mechanism 1-5 is installed on the fuselage and is responsible for adjusting the overall direction of the aircraft. The servo motor controls the rotation angle of the aircraft through its shaft, driving the entire fuselage to rotate around the yaw axis (Yaw axis) to achieve the direction control of the aircraft. Specifically, when the servo shaft rotates, the fuselage rotates around its vertical axis (Yaw axis), allowing the aircraft to adjust its attitude in any direction. Combined with the control of the flapping differential of the wings on both sides, the aircraft can not only hover in the air, but also turn freely and fly in all directions. The rotation of the servo and the differential of the wings on both sides work together to allow the aircraft to accurately complete complex movements such as up and down, left and right, front and back, and steering.

[0091] The servo steering mechanism 1-5 controls the yaw direction (Yaw axis direction) of the aircraft. By controlling the rotation angle of the servo, the yaw direction can be controlled. Traditional flapping-wing aircraft often use multiple servos to adjust the direction and motion trajectory of a single wing to achieve attitude control. The present invention reduces the number of servos and only needs to control the speed of the flapping mechanism motors on both sides to achieve attitude control. This differential control greatly reduces the complexity of control input. Traditional flapping-wing aircraft may need to perform angle control on multiple servos separately to adjust the direction of the aircraft. However, the present invention only needs one servo to control the rotation of the entire body. By inputting a control signal of the rotation angle of a servo, the yaw control of the aircraft can be directly achieved, without the need to gradually adjust the direction through a complex multi-servo control mechanism.

[0092] S4, Lifting and Hovering

[0093] S41, hovering: When the left and right motor speeds are equal, the lift of the left and right wings cancel each other out, and the aircraft remains balanced. If the total lift is equal to the gravity at this time, the aircraft can achieve a hovering state.

[0094] S42, Ascent: When the two motors accelerate at the same time, the flapping frequency of the wings on both sides increases, generating greater lift, and the aircraft will rise.

[0095] S43, descent: On the contrary, the rotation speed of the motors on both sides is reduced, the flapping frequency of the wings is lowered, and the lift is reduced. When it is less than the gravity of the aircraft, the aircraft will gradually descend.

[0096] S5, three-axis attitude control

[0097] The three-axis attitude control (roll, pitch, yaw) of the aircraft is mainly achieved in the following ways:

[0098] S51, Roll axis (Roll) control: Through the differential control of the left and right wings, the flapping frequency difference of the wings on both sides is changed to achieve rotation around the roll axis. The left side has a faster frequency, which produces a right roll, and vice versa, it produces a left roll.

[0099] S52, Pitch control: While the servo controls the yaw of the aircraft, the attitude adjustment around the pitch axis can be achieved by adjusting the relative phase difference of the wing flapping (controlled by the motor).

[0100] S53, Yaw control: It is mainly completed by the servo control mechanism. Through the rotation of the servo shaft, the entire aircraft is driven to yaw around the vertical axis to adjust the flight direction.

[0101] The present invention also proposes a control method based on periodic splitting, which reduces the wing control from three-dimensional precise adjustment to two-dimensional flapping plane precise adjustment, simplifies the control method, is conducive to reducing the coupling of three-axis control torque, improves the control accuracy and reduces the difficulty of flight control. The periodic splitting control includes: the flapping control of the aircraft achieves different torque outputs by adjusting the flapping phase and frequency difference of the wings, thereby achieving precise control of the three-axis attitude. On this basis, the aircraft uses the periodic splitting control method to reduce the complexity in the traditional three-degree-of-freedom control and converts the complex three-dimensional control into precise adjustment of the two-dimensional flapping plane. This adjustment method reduces the coupling of the three-axis control torque, making the flight control more flexible and precise. By adjusting the flapping frequency difference of the wings, the complex adjustment of the three-dimensional attitude of the wings is reduced and simplified to the flapping control of the two-dimensional plane. The flapping motion trajectory of the wings depends on the motor differential control, and the attitude of the aircraft is affected by adjusting the flapping frequency of the wings on both sides. This two-dimensional adjustment method not only simplifies the motion control of the wings, but also reduces the coupling torque problem generated in the multi-degree-of-freedom adjustment process, making the attitude control more precise. The present invention simplifies the complex control of three-dimensional motion through a manipulation method based on periodic splitting, converts complex three-axis attitude adjustment into precise adjustment of a two-dimensional flapping plane, and reduces the influence of torque coupling during three-axis attitude control. This simplification makes the control system more stable and improves the manipulation accuracy. The control system no longer relies on the precise coordination of multiple independent actuators, avoids the control error caused by torque coupling between traditional multiple actuators, and enhances the flexibility of manipulation.

[0102] The aircraft described in the present invention can realize complex flight mode switching, and the aircraft can switch between multiple flight modes according to mission requirements. The model modes include three modes: level flight mode, lifting mode and turning mode. In the level flight mode, the aircraft maintains stable forward movement by adjusting the differential speed of the servo and the flapping mechanism. In the lifting mode, the flapping frequency of the wing is increased so that the lift is greater than the gravity, and the aircraft rises vertically. In the turning mode, the rotation of the servo and the differential speed control of the flapping frequency are combined to realize complex turning actions.

[0103] Traditional flapping-wing aircraft require multiple actuators (such as multiple steering gears or servo motors) to adjust the attitude and tilt of the wings. Especially when achieving three-dimensional motion (such as three-axis attitude control), the coupling between multiple actuators increases the difficulty of control. This multi-actuator structure is not only complex, but also increases the weight of the aircraft, making it difficult to achieve lightweight. In traditional designs, when multiple actuators adjust different wing attitudes, it is easy to produce a coupling effect of attitude torque, which reduces the control accuracy, and the mechanical structure is relatively complex, which is not conducive to miniaturization. The control method of the hovering flapping-wing aircraft based on the rotating structure of the present invention relies on the precise coordination of the motor, gear transmission system, steering gear and flapping wing mechanism. The flapping of the wings is achieved by adjusting the motor speed, and the orientation control of the body is achieved by rotating the steering gear. Combined with differential control and periodic splitting control methods, the aircraft can flexibly and accurately complete complex flight tasks such as multi-axis attitude control, lifting, hovering and steering.

[0104] Chinese patent document CN117622486A discloses a flapping-wing aircraft capable of hovering flight and a control method thereof. The flapping-wing aircraft comprises: a frame; a pair of wings, which are respectively arranged on both sides of the frame; a flapping mechanism, which is used to modulate the flapping angular velocity of the wings in a single cycle so that the flapping angular velocity of the pair of wings is symmetrical within a single cycle; and a control mechanism, which is used to generate a regulating aerodynamic torque at the trailing edge of the wings to achieve motion attitude control of the aircraft.

[0105] Although the Chinese patent document CN117622486A also uses a gear crank transmission, there are obvious substantial differences between the document and the present invention.

[0106] First, the structural designs of the two are different.

[0107] The flapping-wing aircraft in the Chinese patent document CN117622486A uses a flapping mechanism based on a variable diameter pulley. The diameter of the pulley is adjusted to control the flapping angular velocity of the wing, thereby changing the attitude of the aircraft. The core of the transmission mechanism of the flapping mechanism is a pulley system. The motion trajectory of the wing is adjusted by the cooperation of the pulley and the crank gear, and the purpose is to achieve symmetrical flapping of the flapping wing in a single cycle. The present invention uses a rotating structure combined with a gear crank transmission unit, and the motors of the flapping mechanisms on the left and right sides are differentially controlled to achieve omnidirectional motion control of the aircraft. The present invention emphasizes the differential drive of the flapping wings on both sides, and at the same time adjusts the overall direction of the aircraft by rotating the body of the steering gear, and simplifies the mechanical structure to achieve a lighter and miniaturized design. The design of the Chinese patent document CN117622486A controls the movement of the wing through a pulley, while the present invention simplifies the control structure and reduces the mechanical complexity by combining the differential control of the double-sided flapping mechanism with the rotation of the steering gear.

[0108] Second, the control methods of the two are different.

[0109] The control system of Chinese patent document CN117622486A mainly controls the motion attitude of the aircraft by adjusting the aerodynamic torque of the trailing edge of the wing. The flapping speed of the wing is symmetrical within a single cycle, and the focus is on adjusting the airflow distribution at the trailing edge to achieve attitude control. The change of the pulley directly affects the movement angle of the wing, and this method enables the aircraft to achieve direction control and attitude adjustment. The control of the present invention mainly relies on the differential control of the motor and the steering adjustment of the steering gear. By changing the speed of the motors on both sides, the flapping frequency difference of the wings on both sides is adjusted, thereby achieving the pitch and roll control of the aircraft. At the same time, the yaw attitude of the aircraft is adjusted by the steering gear. The control method adopted by the present invention is more direct, reducing complex aerodynamic adjustment, combining differential control with mechanical rotation, improving control accuracy and simplifying the operation method. Chinese patent document CN117622486A pays more attention to achieving attitude control through airflow regulation at the trailing edge of the wing, while the present invention adopts a combination of motor differential and steering gear to achieve a more simplified control method.

[0110] Third, the transmission systems of the two are different.

[0111] The transmission system in Chinese patent document CN117622486A relies on a combination of gears, pulleys and cranks, and changes the flapping speed and angle of the wings by changing the pulley diameter. This method relies on precise mechanical design to ensure the symmetry and control effect of the wing flapping angular velocity. The transmission system of the present invention is relatively simple, relying on the motor to drive the gear crank transmission unit, and realizing the regular flapping of the wings through a series of gears and cranks. The focus of the present invention is on the differential control of the wings on both sides, and the control and adjustment of the posture are realized through the different flapping frequencies on both sides. The transmission system of Chinese patent document CN117622486A is relatively complex and relies on the precise control of the variable diameter pulley, while the present invention adopts a standard gear transmission system to achieve differential control by adjusting the motor speed, and the structure is simpler.

[0112] Fourth, the flight modes of the two are different.

[0113] The flight mode of Chinese patent document CN117622486A relies on precise adjustment of wing shape and flapping angular velocity, especially to achieve symmetrical movement within the flapping cycle to maintain flight stability. The control is complex and suitable for performing precision tasks. The present invention provides a multi-mode flight control through the coordination of servo steering and flapping wing differential. The aircraft can achieve lifting, hovering and multi-directional movement through simple differential control, which is suitable for more flexible and simple control needs. The flight mode of the present invention focuses more on all-round flexible control, and various flight actions are achieved through simple motor speed regulation and servo rotation; Chinese patent document CN117622486A focuses on precise periodic control, and the flight mode relies more on subtle adjustment of the wings.

[0114] Fifth, there are essential differences between the two in terms of simplification and lightweight of mechanical structure.

[0115] Chinese patent document CN117622486A uses multiple control mechanisms (such as pulleys, trailing edge adjustment, etc.). The mechanical structure of this patent is relatively complex, which may affect the overall lightweight design. The present invention focuses on reducing the complexity of the mechanical system by reducing the number of end actuators and simplifying the control structure, thereby achieving the effect of lightweighting and miniaturization of the aircraft. By reducing the number of servos and actuators, the present invention has better lightweight potential. The present invention achieves the purpose of lightweighting by simplifying the mechanical design, while the relatively complex mechanism of Chinese patent document CN117622486A may not be suitable for the design requirements of micro air vehicles.

[0116] In summary, the present invention reduces the reliance on complex servo mechanisms by differentially controlling the motors on the left and right wings. Differential control means that complex three-axis attitude adjustment (including pitch, roll, and yaw) can be achieved by simply controlling the frequency difference of the flapping of the wings on both sides. This design avoids complex attitude adjustment of single-sided wings and simplifies the entire control system. By adjusting the speed of two motors to achieve roll and pitch attitude control, compared with the traditional method of adjusting the wing attitude with multiple actuators, the present invention reduces the complexity and coupling effect of the control system while achieving efficient control. The present invention greatly reduces the weight of the aircraft by reducing the number of end actuators (such as multiple servos or servo motors). This lightweight design is conducive to improving the hovering ability and maneuverability of flapping-wing aircraft. At the same time, the simplified structure is easier to miniaturize, allowing the aircraft to fly flexibly in a small space.

[0117] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the scope of protection determined by the claims of the present invention.

Claims

1. A hovering flapping-wing aircraft based on a rotating structure, characterized in that: The aircraft comprises: an aircraft body, a steering gear steering mechanism (1-5), a first flapping mechanism (1-3a) and a second flapping mechanism (1-3b); the aircraft body comprises a fuselage and a wing assembly one and a wing assembly two respectively arranged on both sides of the fuselage; the wing assembly one and the wing assembly two each comprise two wings; the steering gear steering mechanism (1-5), the first flapping mechanism (1-3a) and the second flapping mechanism (1-3b) are all mounted on the fuselage; the first flapping mechanism (1-3a) is connected to the two wings in the wing assembly one, and the second flapping mechanism (1-3b) is connected to the two wings in the wing assembly two; The servo steering mechanism (1-5) is used to rotate the aircraft body, change the orientation of the aircraft body, and cooperate with the differential speed of the two flapping mechanisms to achieve flight control of the aircraft in different directions; the first flapping mechanism (1-3a) is used to drive the two wings in the wing assembly one to produce flapping motion to provide lift and perform wing attitude control; the second flapping mechanism (1-3b) is used to drive the two wings in the wing assembly two to produce flapping motion, and cooperate with the first flapping mechanism to adjust the flapping differential speed of the wings on both sides of the fuselage to achieve balance and steering control of the aircraft.

2. The hovering flapping-wing aircraft based on a rotating structure according to claim 1, characterized in that: The wing assembly 1 comprises a first wing (1-4a) and a second wing (1-4b); the wing assembly 2 comprises a third wing (1-4c) and a fourth wing (1-4d); the first wing (1-4a), the second wing (1-4b), the third wing (1-4c) and the fourth wing (1-4d) all comprise a wing surface (6-1) and a connecting rod (6-2).

3. The hovering flapping-wing aircraft based on a rotating structure according to claim 1, characterized in that: The fuselage comprises a central connecting rod (1-2) and a steering gear cantilever arranged in parallel, and a central frame (1-1) located between the central connecting rod (1-2) and the steering gear cantilever; Two connecting rods (4-5) are arranged between the central connecting rod (1-2) and the second fixing portion; A first central hole (5-1) is provided in the middle of the central connecting rod (1-2), a first motor mounting hole (5-3a) and a second motor mounting hole (5-3b) are provided at both ends of the central connecting rod (1-2), and a first connecting rod fixing hole (5-2a) and a second connecting rod fixing hole (5-2b) are also provided on the central connecting rod (1-2); A second central hole (4-3) is provided in the middle of the steering gear cantilever, and a third connecting rod fixing hole (4-4a) and a fourth connecting rod fixing hole (4-4b) are respectively provided at both ends.

4. The hovering flapping-wing aircraft based on a rotating structure according to claim 3 is characterized in that: The central frame (1-1) comprises a boss base (2-1), a support shaft mounted on the top of the boss base (2-1), and a ball bearing (2-2) connected to the support shaft; the ball bearing (2-2) is mounted in a first central hole (5-1); and a first steering gear mounting hole (2-3a) and a second steering gear mounting hole (2-3b) are provided at the bottom of the boss base (2-1).

5. The hovering flapping-wing aircraft based on a rotating structure according to claim 1, characterized in that: The steering gear steering mechanism (1-5) comprises a steering gear; the steering gear comprises a steering gear body, a steering gear motor shaft (4-2) arranged on the steering gear body, and a first mounting portion (4-1a) and a second mounting portion (4-1b) arranged on both sides of the steering gear body; the steering gear motor shaft (4-2) is mounted in the second center hole (4-3); the first mounting portion (4-1a) and the first steering gear mounting hole (2-3a) are arranged correspondingly, and the second mounting portion (4-1b) and the second steering gear mounting hole (2-3b) are arranged correspondingly, so as to fix the steering gear on the boss base (2-1).

6. The hovering flapping-wing aircraft based on a rotating structure according to claim 2, characterized in that: The first flapping mechanism (1-3a) and the second flapping mechanism (1-3b) have the same structure, and both comprise a motor (3-1), a bracket (3-2) and a gear crank transmission unit; the crank gear transmission unit comprises a first gear (3-3), a double gear (3-4), a second gear (3-5a), a third gear (3-5b), a first crank (3-6a) and a second crank (3-6b); an output shaft of the motor (3-1) is connected to the first gear (3-3); the double gear (3-4) comprises an upper gear and a lower gear arranged on the same shaft; the first gear (3-3) is meshed and connected to the lower gear; the upper gear is meshed and connected to the first gear (3-3); The two gears (3-5a) are meshed and connected; the second gear (3-5a) and the third gear (3-5b) are meshed and connected; one end of the first crank (3-6a) is mounted on the second gear (3-5a), and one end of the second crank (3-6b) is mounted on the third gear (3-5b); the other end of the first crank (3-6a) is connected to the front end of the bracket (3-2) to drive the flapping of the first wing (1-4a); the other end of the second crank (3-6b) is connected to the connection point at the rear of the bracket (3-2) to drive the flapping of the second wing (1-4b); and the symmetrical flapping of the wings is achieved through the coordinated movement of the gear transmission and the crank.

7. The hovering flapping-wing aircraft based on a rotating structure according to claim 6, characterized in that: The support (3-2) comprises a support frame; a central circular hole (3-2-4) is arranged in the middle of the support frame; a plurality of reinforcing ribs are arranged between the outer periphery of the central circular hole (3-2-4) and the inner wall of the support frame; a first cylindrical structure (3-2-1), a second cylindrical structure (3-2-2) and a third cylindrical structure (3-2-3) protruding upward are arranged on the top of the support frame; the first cylindrical structure (3-2-1) is connected to the second gear (3-5a); the second cylindrical structure (3-2-2) is connected to the third gear (3-5b); The third cylindrical structure (3-2-3) is connected to the double gear (3-4); a connecting hole (3-2-5) is also provided on the top of the support frame, and a leading edge connecting member is installed in the connecting hole (3-2-5); the leading edge connecting member comprises a first leading edge connecting member (3-7a) and a second leading edge connecting member (3-7b); one end of the connecting rod (6-2) extending out is fixedly connected to the leading edge connecting member of the flapping mechanism; the first leading edge connecting member (3-7a) and the second leading edge connecting member (3-7b) are respectively connected to the connecting rods (6-2) in the two wings in the same side wing assembly.

8. The control method of a hovering flapping-wing aircraft based on a rotating structure according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: S1. Start the aircraft After the aircraft is started, the motors (3-1) of the two flapping mechanisms start to operate, driving the corresponding gear crank transmission units to operate, and the gear crank transmission units drive each wing to flap; S2. Flutter control and posture adjustment By controlling the rotation speed of the motors (3-1) in the two flapping mechanisms, the left and right sets of wings are made to flap at a certain frequency; if the flapping frequencies of the wings on the left and right sides of the fuselage are equal, the aircraft generates an upward lift; by adjusting the rotation speed of the motors in the two flapping mechanisms, the difference in flapping frequencies of the wings on the left and right sides of the fuselage is changed by using the differential speed control of the motors in the two flapping mechanisms, so as to adjust the attitude of the aircraft: S3, steering gear control The servo controls the rotation angle of the aircraft through the servo motor shaft. The rotation of the servo motor shaft drives the entire fuselage to rotate around the yaw axis, allowing the aircraft to adjust its attitude in any direction to achieve the orientation control of the aircraft.

9. The control method of the hovering flapping-wing aircraft based on the rotating structure according to claim 8 is characterized in that: After the aircraft is started, the motors (3-1) of the two flapping mechanisms start to operate, driving the corresponding gear crank transmission units to operate, and the gear crank transmission units drive each wing to flap, including: The output shaft of the motor (3-1) meshes with the first gear (3-3) to transmit power to the double gear (3-4), and the double gear (3-4) then transmits the power to the second gear (3-5a) and the third gear (3-5b) respectively, thereby achieving two-stage reduction; the second gear (3-5a) and the third gear (3-5b) respectively drive the first leading edge connecting member (3-7a) and the second leading edge connecting member (3-7b) to move through the first crank (3-6a) and the second crank (3-6b), thereby driving each wing to perform flapping motion; The method of adjusting the rotation speed of the motors in the two flapping mechanisms and utilizing the differential speed control of the motors in the two flapping mechanisms to change the flapping frequency difference of the wings on the left and right sides of the fuselage to adjust the attitude of the aircraft includes: By increasing the rotation speed of the motor (3-1) in the left flapping mechanism, the flapping frequency of the left wing is greater than the flapping frequency of the right wing, the lift generated by the left wing is greater than the lift generated by the right wing, and the aircraft rotates counterclockwise around its roll axis; by increasing the rotation speed of the motor (3-1) in the right flapping mechanism, the flapping frequency of the right wing is greater than the flapping frequency of the left wing, the lift generated by the right wing is greater than the lift generated by the left wing, and the aircraft rotates clockwise around its roll axis.

10. The control method of the hovering flapping-wing aircraft based on a rotating structure according to claim 8, characterized in that: The method further includes: S4, lifting and hovering control S41, hovering: when the motor speeds in the flapping mechanisms on the left and right sides are equal, the lifts of the wings on the left and right sides cancel each other out, and the aircraft maintains balance. If the total lift of the aircraft is equal to the gravity at this time, the aircraft achieves a hovering state; S42, ascending: the motors in the flapping mechanisms on the left and right sides are accelerated at the same time, the flapping frequency of the wings on both sides is increased, and the lift of the wings on both sides is increased. If the total lift of the aircraft is greater than the gravity at this time, the aircraft ascends; S43, descending: reducing the rotation speed of the motors in the flapping mechanisms on the left and right sides, reducing the flapping frequency of the wings on both sides, and reducing the lift of the wings on both sides. If the total lift of the aircraft is less than the gravity of the aircraft at this time, the aircraft descends; S5, three-axis attitude control S51, Roll axis Roll control: By differentially controlling the left and right wings, the flapping frequency difference of the wings on both sides is changed to realize the rotation of the aircraft around the roll axis. If the left frequency is faster, it will roll to the right, otherwise it will roll to the left; S52, pitch axis Pitch control: while the servo controls the yaw of the aircraft, the relative phase difference of the wing flapping is adjusted by controlling the speed of the motors in the flapping mechanisms on both sides to achieve attitude adjustment around the pitch axis; S53, Yaw control: By rotating the servo shaft, the entire aircraft is driven to yaw around the vertical axis to adjust the flight direction; S6. Periodic split control: During the flapping control of the aircraft, different torques are output by adjusting the flapping phase and frequency difference of the wings to achieve three-axis attitude control.

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