Double-section flapping wing bionic aircraft based on multiple spatial connecting rods

Abstract

The invention relates to the technical field of bionic aircrafts, and discloses a double-section flapping wing bionic aircraft based on multiple spatial connecting rods, the double-section flapping wing bionic aircraft comprises an aircraft main body, wings and a driving device, the wings are symmetrically arranged on the two sides of the aircraft main body, and each wing comprises an inner wing rod, a track rod, a connecting plate, an outer wing rod and a transmission assembly; one end of the inner wing rod and one end of the track rod are hinged to the aircraft body, the inner wing rod and the track rod are arranged in a staggered mode on different planes, the other end of the inner wing rod and the other end of the track rod are hinged to the connecting plate, and one end of the outer wing rod is fixedly connected with the connecting plate. The rotating wheel is provided with an eccentric shaft, the eccentric shaft is in ball joint with one end of a connecting rod, the other end of the connecting rod is in ball joint with the inner wing rod, and the driving device is installed on the aircraft body and connected with the rotating wheel and can drive the rotating wheel to rotate at a constant speed. The structure is simple and compact, the movement is reliable, and the rotation amplitude of the outer wing rod is large.

Description

Technical Field

[0001] The present invention relates to the technical field of bionic aircraft, and particularly to a dual-segment flapping-wing bionic aircraft based on a spatial multi-link mechanism. Background Art

[0002] In recent years, as a new concept of aircraft design, bionic aircraft have received extensive attention due to their unique advantages in flexibility, maneuverability, and energy efficiency. A flapping-wing aircraft is an aircraft that generates lift and propulsion by imitating the wing flapping of natural organisms such as birds and insects. The core of this aircraft lies in the design of its flapping mechanism, that is, how to achieve the bionic movement of the wings through a mechanical structure to meet the flight requirements.

[0003] The existing aircraft usually achieve the flapping of the wings through the following mechanisms:

[0004] (1) Single crank double rocker mechanism: This mechanism drives the connecting rod and rocker arm through the rotation of the crank, causing the wings to perform periodic reciprocating swings. The advantage is simple structure. However, the flapping of the left and right wings is not synchronized, which easily leads to unstable flight.

[0005] (2) Planar double crank double rocker mechanism: The double cranks rotate around the fulcrums respectively, and drive the rockers through the connecting rod, causing the wings to flap symmetrically. The design and optimization are relatively simple, and it is applicable to single-segment and multi-segment flapping-wing aircraft. However, the space is not compact enough, and it will increase the size and weight of the aircraft fuselage, and the fixation of the mechanism is more cumbersome.

[0006] (3) Spatial link mechanism: The spatial link mechanism realizes the relative movement in space by connecting multiple rockers on an output shaft, and then drives the flapping of the aircraft wings. This mechanism is compact and the movement is reliable. However, due to the structural characteristics of the spatial link, the design and manufacture of a dual-segment aircraft are difficult, and this mechanism is difficult to be applied to a dual-segment flapping-wing aircraft. Therefore, it is mainly used in single-segment bionic flapping-wing aircraft at present.

[0007] (4) Crank-slider mechanism: The crank drives the slider to slide in the slideway, and the movement of the slider causes the wings to swing. The advantage of this mechanism is the high synchronization of the two wings. However, its frictional resistance is large, especially when flapping at high speed, the wear is serious. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a dual-segment flapping-wing bionic aircraft based on a spatial multi-link mechanism, which has a simple and compact structure, reliable movement, and a large rotation amplitude of the outer wing rod.

[0009] To solve the above technical problems, the present invention provides a dual-segment flapping-wing bionic aircraft based on a spatial multi-link mechanism, comprising an aircraft body, wings, and a driving device. The wings are symmetrically arranged on both sides of the aircraft body. The wing comprises an inner wing rod, a track rod, a connecting plate, an outer wing rod, and a transmission assembly. One end of the inner wing rod and one end of the track rod are respectively hinged to the aircraft body. The inner wing rod and the track rod are arranged in a skew and staggered manner in different planes. The other end of the inner wing rod and the other end of the track rod are respectively hinged to the connecting plate. One end of the outer wing rod is fixedly connected to the connecting plate. The transmission assembly comprises a rotating wheel and a connecting rod. The rotating wheel is arranged on one side of the aircraft body. An eccentric shaft is provided on the rotating wheel. The eccentric shaft is ball-jointed to one end of the connecting rod. The other end of the connecting rod is ball-jointed to the inner wing rod. The driving device is installed on the aircraft body and connected to the rotating wheel. The driving device can drive the rotating wheel to rotate at a constant speed.

[0010] As a preferred solution of the present invention, the wing further comprises an inner wing auxiliary rod and an outer wing auxiliary rod. The inner wing auxiliary rod is arranged in parallel on one side of the inner wing rod. One end of the inner wing auxiliary rod is hinged to the aircraft body. The other end of the inner wing auxiliary rod is hinged to one end of the outer wing auxiliary rod. The outer wing auxiliary rod is parallel to the outer wing rod. An inner wing skeleton rod fixedly connected to the inner wing auxiliary rod is provided on the side of the inner wing rod. An outer wing skeleton rod fixedly connected to the outer wing auxiliary rod is provided on the side of the outer wing rod.

[0011] As a preferred solution of the present invention, the driving device comprises a motor, a driving gear, a reduction gear, and a transmission gear. The driving gear is arranged on the output shaft of the motor and meshes with the reduction gear. The transmission gear is coaxially arranged on the reduction gear and meshes with the rotating wheel.

[0012] As a preferred solution of the present invention, the motor is installed on one side of the aircraft body. The driving gear and the reduction gear are arranged on the other side of the aircraft body. The output shaft of the motor can rotatably pass through the aircraft body and is connected to the driving gear.

[0013] As a preferred solution of the present invention, the transmission gear passes through the aircraft body and meshes with the rotating wheels located on both sides of the aircraft body respectively.

[0014] As a preferred solution of the present invention, a first bearing seat and a second bearing seat are provided on the side of the aircraft body. A first connecting block is detachably connected to the end of the inner wing rod. The first connecting block is hinged to the first bearing seat. The first connecting block is ball-jointed to the connecting rod. A second connecting block is detachably connected to the end of the track rod. The second connecting block is hinged to the second bearing seat.

[0015] As a preferred embodiment of the present invention, the aircraft further includes a first servo, a servo bracket, a second servo, a tail seat and a tail fin rod. The first servo is installed on one side of the aircraft body. The servo bracket is swingably installed at the tail of the aircraft body. The second servo is installed on the servo bracket. The output end of the first servo is connected to the servo bracket through a transmission mechanism and can drive the servo bracket to swing. The tail seat is installed on the output end of the second servo, and the tail fin rod is fixed on the tail seat.

[0016] As a preferred embodiment of the present invention, the transmission mechanism includes a first swing arm, a pull rod and a second swing arm. One end of the first swing arm is fixedly connected to the output end of the first servo, and the other end of the first swing arm is hinged to one end of the pull rod. The second swing arm is L-shaped, the middle of the second swing arm is hinged to the tail of the aircraft body, one end of the second swing arm is hinged to the other end of the pull rod, and the servo bracket is installed on the other end of the second swing arm.

[0017] As a preferred embodiment of the present invention, the wing satisfies the following design conditions:

[0018] Taking the hinge point of the track rod and the aircraft body as the origin, a space rectangular coordinate system is established. Among them, the axial direction of the rotating wheel is the X-axis direction, the hinge axis of the track rod and the aircraft body is the Y-axis, the hinge point of the inner wing rod and the aircraft body is point A, the hinge point of the track rod and the aircraft body is point B, a connecting shaft is provided on one side of the inner wing rod, the connecting shaft is ball-jointed with one end of the connecting rod, the connecting point of the inner wing rod and the connecting shaft is point C, the ball-joint point of the connecting shaft and the connecting rod is point C1, and the distance between point C and point C1 is L Cpin , the ball-joint point of the connecting rod and the eccentric shaft is point G, the center of the end face of the rotating wheel is point O1, the distance from the connecting point of the eccentric shaft and the rotating wheel to point O1 is R, and the rotation angle of the rotating wheel is n is the rotation speed of the rotating wheel, t is the time, the hinge point of the inner wing rod and the connecting plate is point E, the hinge point of the track rod and the connecting plate is point F, and the angle between the inner wing rod and the X-axis is θ A , the projection point of point F along the Y-axis on the track rod is point F1, and the distance between F and F1 is L Fpin , the angle between the line connecting point E and point F1 and the X-axis is θ FE , the angle between the line connecting point E and point F1 and the outer wing rod is β, and the angle between the outer wing rod and the X-axis is α;

[0019] The coordinates of point C are: C = (A x +L AC cosθA , A y , A z +L AC sinθ A );

[0020] The coordinates of point C1 are: C1 = C + (0, L Cpin , 0) = (A x +L AC cosθ A , A y +L Cpin , A z +L AC sinθ A );

[0021] The coordinates of point G are:

[0022] The distance between point C1 and point G is L C1G , and L C1G 2 = ||G1 - G|| 2 , that is:

[0023] The coordinates of point E are: E = (A x +L AE cosθ A , E y , A z +L AE sinθ A );

[0024] The coordinates of point F1 are: F1 = (F1 x , E y , F1 z ), where,

[0025]

[0026] E y = L Fpin ,

[0027]

[0028] The coordinates of point F are: F = (F1 x , 0, F1 z );

[0029] θ EF = atan2(E x - F1 x , E z - F1 z );

[0030] α = θ EF -β.

[0031] In an embodiment of the present invention, a dual-segment flapping bionic aircraft based on a spatial multi-link mechanism, compared with the prior art, has the following beneficial effects: The connecting rods in this embodiment are ball-jointed to the inner wing rods and the eccentric shafts respectively, and together with the inner wing rods, the track rods, the connecting plates and the outer wing rods, a spatial link mechanism is formed. By ball-jointing the connecting rods to the inner wing rods and the eccentric shafts on the rotating wheels respectively, the movement of the inner wing rods is driven by the rotating wheels, effectively reducing the number of transmission parts required from the rotating wheels to the inner wing rods; One end of the inner wing rod and one end of the track rod are respectively hinged to the aircraft body, and the other end of the inner wing rod and the other end of the track rod are respectively hinged to the connecting plate, simplifying the structure, thereby reducing the assembly complexity and maintenance cost of the aircraft; The inner wing rod and the track rod are arranged in a skew and staggered manner, with a more flexible layout, which helps to reduce the overall volume and can effectively increase the swing amplitude of the outer wing rod, resulting in a better bionic flight effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is the structural diagram of the present invention;

[0033] Figure 2 is Figure 1 the partial enlarged view of point A of

[0034] Figure 3 is the structural diagram of the present invention from another angle;

[0035] Figure 4 is Figure 3 the partial enlarged view of point B of

[0036] Figure 5 is Figure 3 the partial enlarged view of point C of

[0037] Figure 6 is the top view of the present invention;

[0038] Figure 7 is Figure 6 the partial enlarged view of point D of

[0039] Figure 8 is the structural diagram of the present invention from another angle;

[0040] Figure 9 Figure 8 the partial enlarged view of point E of

[0041] Figure 10 is the motion trajectory diagram of the present invention;

[0042] Figure 11 is the mechanism schematic diagram of the present invention in the XZ plane;

[0043] Figure 12 is the schematic diagram of the mechanism of the present invention in the XY plane;

[0044] Figure 13 is the schematic diagram of the mechanism of the present invention in the YZ plane;

[0045] In the figure, 1 is the aircraft body; 11 is the first bearing seat; 12 is the second bearing seat; 2 is the wing; 21 is the inner wing rod; 211 is the first connecting block; 22 is the track rod; 221 is the second connecting block; 23 is the connecting plate; 24 is the outer wing rod; 25 is the transmission assembly; 251 is the rotating wheel; 252 is the connecting rod; 253 is the eccentric shaft; 26 is the inner wing auxiliary rod; 261 is the inner wing skeleton rod; 27 is the outer wing auxiliary rod; 271 is the outer wing skeleton rod; 3 is the driving device; 31 is the motor; 32 is the driving gear; 33 is the reduction gear; 34 is the transmission gear; 4 is the first servo; 41 is the servo bracket; 42 is the second servo; 43 is the tail seat; 44 is the tail wing rod; 45 is the first swing arm; 46 is the pull rod; 47 is the second swing arm. Detailed implementation manners

[0046] The following combines the accompanying drawings and embodiments to further describe in detail the specific implementation manners of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0047] In the description of the present invention, it should be understood that the present invention uses terms such as "center", "longitudinal", "transverse", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0048] Such as Figures 1-13As shown in the figure, a double-segment flapping-wing bionic aircraft based on a spatial multi-link 252 according to a preferred embodiment of the present invention includes an aircraft body 1, wings 2, and a driving device 3. Wings 2 are symmetrically arranged on both sides of the aircraft body 1. The wing 2 includes an inner wing rod 21, a track rod 22, a connecting plate 23, an outer wing rod 24, and a transmission component 25. One end of the inner wing rod 21 and one end of the track rod 22 are respectively hinged to the aircraft body 1. The inner wing rod 21 and the track rod 22 are arranged in a skew and non-intersecting manner, that is, the inner wing rod 21 and the track rod 22 are neither parallel nor intersecting. In this embodiment, an upper hinge portion and a lower hinge portion are provided on the side of the aircraft body 1. The inner wing rod 21 is hinged to the upper hinge portion, and the track rod 22 is hinged to the lower hinge portion. It should be noted that the upper hinge portion is not directly above the lower hinge portion. The other end of the inner wing rod 21 and the other end of the track rod 22 are respectively hinged to the connecting plate 23. The hinge axis of the inner wing rod 21 and the aircraft body 1, the hinge axis of the track rod 22 and the aircraft 1, the hinge axis of the inner wing rod 21 and the connecting plate 23, and the hinge axis of the track rod 22 and the connecting plate 23 are parallel to each other. In this embodiment, the connecting plate 23 is provided with an upper connecting portion and a lower connecting portion. The upper connecting portion is not directly above the lower connecting portion. The inner wing rod 21 is hinged to the lower connecting portion, and the track rod 22 is hinged to the upper connecting portion. One end of the outer wing rod 24 is fixedly connected to the connecting plate 23. Generally, the connection point of the outer wing rod 24 and the connecting plate 23, the hinge point of the inner wing rod 21 and the connecting plate 23, and the hinge of the track rod 22 and the connecting plate 23 are arranged in a triangular shape. The transmission component 25 includes a rotating wheel 251 and a connecting rod 252. The rotating wheel 251 is arranged on one side of the aircraft body 1. An eccentric shaft 253 is provided on the rotating wheel 251. The eccentric shaft 253 is ball-jointed (through a spherical joint) with one end of the connecting rod 252. The other end of the connecting rod 252 is ball-jointed with the inner wing rod 21. The driving device 3 is installed on the aircraft body 1 and is connected to the rotating wheel 251. The driving device 3 can drive the rotating wheel 251 to rotate at a constant speed.

[0049] The working principle of this embodiment is as follows: The driving device 3 drives the rotating wheel 251 to rotate, thereby driving the connecting rod 252 to move through the eccentric shaft 253. The movement of the connecting rod 252 can be decomposed into two component movements. The first component movement is that the rotating wheel 251 drives the connecting rod 252 through the eccentric shaft 253, causing the connecting rod 252 to rotate around the axis of the rotating wheel 251. The second component movement is that since the length of the connecting rod 252 is fixed and the two ends of the connecting rod 252 are respectively ball-jointed to the inner wing rod 21 and the eccentric shaft 253, the connecting rod 252 will rotate around the axis of the eccentric shaft 253. Since one end of the connecting rod 252 is ball-jointed to the inner wing rod 21 and one end of the inner wing rod 21 is hinged to the aircraft body 1, the inner wing rod 21 will rotate regularly (rotate around the hinge axis of the inner wing rod 21 and the aircraft body 1) under the drive of the connecting rod 252. This process mainly controls the movement of the inner wing rod 21. Since the other end of the inner wing rod 21 is hinged to the connecting plate 23, the inner wing rod 21 will drive the connecting plate 23 to move. The movement of the connecting plate 23 can be decomposed into three component movements. The first component movement is that the inner wing rod 21 drives the connecting plate 23 to rotate around the hinge axis of the inner wing rod 21 and the aircraft body 1. The second component movement is that since one end of the track rod 22 is hinged to the aircraft body 1 and the other end of the track rod 22 is hinged to the connecting plate 23, the connecting plate 23 will rotate around the hinge axis of the track rod 22 and the aircraft body 1, and the track rod 22 will rotate together as a follower under the drive of the connecting plate 23. This process mainly controls the movement of the track rod 22. The third component movement is that since the length of the track rod 22 and the position of the hinge axis are determined, and there is a certain distance in space between the hinge axes of the aircraft body 1 and the inner wing rod 21 and the track rod 22 respectively, the track rod 22 can be used as a guiding member to drive the connecting plate 23 to rotate around the hinge axis of the connecting plate 23 and the inner wing rod 21. Since the connecting plate 23 is fixedly connected to one end of the outer wing rod 24, this process can control the movement of the outer wing rod 24. Through the description of the above movement process, the spatial multi-link 252 mechanism of the present invention can complete the flapping wing movement, and the movement trajectory is as Figure 10 shown.

[0050] In the traditional double-crank rocker mechanism of the prior art, the gear and the connecting rod mechanism must be constructed in the same two-dimensional space, which makes it difficult to reduce the volume of the aircraft fuselage, thereby increasing the windward area of the aircraft and increasing the weight of the aircraft. The present invention creatively designs a special spatial connecting rod mechanism. This structural design makes the layout of the components of the flapping wing aircraft more flexible, allowing for multiple layout possibilities, and effectively reducing the volume of the aircraft.

[0051] In the double-crank rocker mechanism of the traditional two-section flapping wing, the track rod and the crank form a rotating pair, and the crank forms a rotating pair with the inner wing rod and the rotating wheel respectively. This structure has high requirements for the strength of the crank and is complex in structure. In the special connecting rod structure designed in the present invention, one end of the track rod forms a rotating pair with the aircraft body (fixed hinge support fixed thereon), and the other end forms a rotating pair with the connecting plate, reducing the assembly complexity and maintenance cost of the aircraft.

[0052] In the traditional two-section flapping wing aircraft, the hinge point between the inner wing rod and the aircraft body in the double-crank rocker mechanism is not at the end of the rod. Therefore, in addition to setting a rotating pair at the end of the inner wing rod, additional connecting parts need to be added in the middle of the inner wing rod and rods and fixing plates need to be added on the aircraft body to form a rotating pair with the inner wing rod. In the special connecting rod structure designed in the present invention, because of the compact structure and the introduction of spherical pairs (the two ends of the connecting rod are respectively ball-jointed with the inner wing rod and the eccentric shaft), the connecting rod can directly form a rotating pair with the end of the inner wing rod, effectively simplifying the structure.

[0053] The connecting rod 252 of this embodiment is respectively ball-jointed with the inner wing rod 21 and the eccentric shaft 253, and forms a spatial connecting rod 252 mechanism with the inner wing rod 21, the track rod 22, the connecting plate 23 and the outer wing rod 24. Compared with the existing structure of the two-section flapping wing aircraft, in this embodiment, by ball-jointing the connecting rod 252 with the inner wing rod 21 and the eccentric shaft 253 on the rotating wheel 251 respectively, the rotating wheel 251 is enabled to drive the inner wing rod 21 to move, effectively reducing the number of transmission parts required between the rotating wheel 251 and the inner wing rod 21; one end of the inner wing rod 21 and one end of the track rod 22 are respectively hinged to the aircraft body 1, and the other end of the inner wing rod 21 and the other end of the track rod 22 are respectively hinged to the connecting plate 23, simplifying the structure, thereby reducing the assembly complexity and maintenance cost of the aircraft; the inner wing rod 21 and the track rod 22 are arranged in a skew and staggered manner, with a more flexible layout, which helps to reduce the overall volume and can effectively increase the swing amplitude of the outer wing rod 24 (the range of angles that can rotate is larger), and the bionic flight effect is better.

[0054] Exemplarily, the wing 2 further includes an inner wing auxiliary rod 26 and an outer wing auxiliary rod 27. The inner wing auxiliary rod 26 is disposed parallel to one side of the inner wing rod 21. One end of the inner wing auxiliary rod 26 is hinged to the aircraft body 1, and the other end of the inner wing auxiliary rod 26 is hinged to one end of the outer wing auxiliary rod 27. The outer wing auxiliary rod 27 is parallel to the outer wing rod 24. An inner wing skeleton rod 261 fixedly connected to the inner wing auxiliary rod 26 is provided on the side of the inner wing rod 21, and an outer wing skeleton rod 271 fixedly connected to the outer wing auxiliary rod 27 is provided on the side of the outer wing rod 24. The inner wing rod 21 is connected to the inner wing auxiliary rod 26 through the inner wing skeleton rod 261, so that the inner wing rod 21 and the inner wing auxiliary rod 26 move synchronously. The outer wing rod 24 is connected to the outer wing auxiliary rod 27 through the outer wing skeleton rod 271, so that the outer wing rod 24 and the outer wing auxiliary rod 27 move synchronously. The settings of the inner wing auxiliary rod 26 and the outer wing auxiliary rod 27 can ensure the stability of the aircraft during flight.

[0055] Exemplarily, the driving device 3 includes a motor 31, a driving gear 32, a reduction gear 33 and a transmission gear 34. The driving gear 32 is disposed on the output shaft of the motor 31 and meshes with the reduction gear 33. The transmission gear 34 is coaxially disposed on the reduction gear 33 and meshes with the rotating wheel 251. It can be understood that the rotating wheel 251 is a gear meshing with the reduction gear 33. When the output shaft of the motor 31 rotates, through the transmission of the driving gear 32, the reduction gear 33 and the transmission gear 34, the rotation of the rotating wheel 251 is driven.

[0056] Exemplarily, the motor 31 is installed on one side of the aircraft body 1, and the driving gear 32 and the reduction gear 33 are disposed on the other side of the aircraft body 1. The output shaft of the motor 31 can rotatably pass through the aircraft body 1 and be connected to the driving gear 32, making full use of the space on both sides of the aircraft body 1, with a compact structure, which helps to reduce the overall volume of the aircraft and helps the aircraft body 1 to maintain stability.

[0057] In the traditional double-segment flapping-wing aircraft, the last-stage two gears in the reduction gear 33 group are meshed with each other and each drives a crank to drive the crank-rocker mechanism. However, the backlash in the gear transmission will cause a certain phase difference between the two cranks, which may lead to a phase difference in the movement of the rocker mechanisms on both sides of the aircraft. Exemplarily, the transmission gear 34 passes through the aircraft body 1 and meshes with the rotating wheels 251 located on both sides of the aircraft body 1, that is, the transmission gear 34 is connected to the two rotating wheels 251 at the same time, realizing the synchronous swing of the two wings 2. Therefore, compared with the existing double-rocker mechanism, the present invention is more accurate in motion control, reduces the motion error, and improves the stability and controllability of the aircraft.

[0058] Exemplarily, a first bearing seat 11 and a second bearing seat 12 are provided on the side of the aircraft body 1. A first connection block 211 is detachably connected to the end of the inner wing rod 21. The first connection block 211 is hinged to the first bearing seat 11, and the first connection block 211 is ball-jointed to the connecting rod 252. A second connection block 221 is detachably connected to the end of the track rod 22. The second connection block 221 is hinged to the second bearing seat 12. With the above settings, the inner wing rod 21 and the track rod 22 of different lengths can be quickly replaced to adjust the flapping amplitude of the wing 2.

[0059] Exemplarily, the aircraft further includes a first servo 4, a servo bracket 41, a second servo 42, a tail seat 43, and a tail wing rod 44. The first servo 4 is installed on one side of the aircraft body 1. The servo bracket 41 is swingably installed at the tail of the aircraft body 1. The second servo 42 is installed on the servo bracket 41. The output end of the first servo 4 is connected to the servo bracket 41 through a transmission mechanism and can drive the servo bracket 41 to swing. The tail seat 43 is installed on the output end of the second servo 42. The tail wing rod 44 is fixed to the tail seat 43. The first servo 4 can drive the servo bracket 41, the second servo 42, the tail seat 43, and the tail wing rod 44 to swing. The second servo 42 can drive the tail seat 43 and the tail wing rod 44 to swing. That is, the two servos respectively control the tail wing rod 44 to move in a single degree of freedom. By controlling the servos to drive the swing of the tail wing, the pitch and steering control of the aircraft are realized.

[0060] Exemplarily, the transmission mechanism includes a first swing arm 45, a pull rod 46, and a second swing arm 47. One end of the first swing arm 45 is fixedly connected to the output end of the first servo 4. The other end of the first swing arm 45 is hinged to one end of the pull rod 46. The second swing arm 47 is L-shaped. The middle of the second swing arm 47 is hinged to the tail of the aircraft body 1. One end of the second swing arm 47 is hinged to the other end of the pull rod 46. The servo bracket 41 is installed on the other end of the second swing arm 47. When the output end of the first servo 4 drives the first swing arm to rotate, the second swing arm 47 is driven by the pull rod 46, thereby driving the servo bracket 41 and the second servo 42 to swing.

[0061] Exemplarily, the wing 2 satisfies the following design conditions:

[0062] Such as Figures 11-13As shown, a spatial rectangular coordinate system is established with the hinge point of the track rod 22 and the aircraft body 1 as the origin (each component is simplified to a line, and the error caused by the simplification is acceptable). Among them, the axial direction of the rotating wheel 251 is the X-axis direction, the hinge axis of the track rod 22 and the aircraft body 1 is the Y-axis, the hinge point of the inner wing rod 21 and the aircraft body 1 is point A, the hinge point of the track rod 22 and the aircraft body 1 is point B. A connecting shaft is provided on one side of the inner wing rod 21, and the connecting shaft is arranged along the Y-axis direction. The connecting shaft is ball-jointed with one end of the connecting rod 252. The connecting point of the inner wing rod 21 and the connecting shaft is point C, and the ball-joint point of the connecting shaft and the connecting rod 252 is point C1. The distance between point C and point C1 is L Cpin , the ball-joint point of the connecting rod 252 and the eccentric shaft 253 is point G, the center of the end face of the rotating wheel 251 is point O1, the distance from the connecting point of the eccentric shaft 253 and the rotating wheel 251 to point O1 is R, and the rotation angle of the rotating wheel is n is the rotation speed of the rotating wheel, t is the time, the hinge point of the inner wing rod 21 and the connecting plate 23 is point E, the hinge point of the track rod 22 and the connecting plate 23 is point F, and the angle between the inner wing rod 21 and the X-axis is θ A , the projection point of point F on the track rod 22 along the Y-axis direction is point F1 (in the actual structure, the track rod 22 is hinged to the connecting plate 23 through a pin shaft arranged along the Y-axis direction, and point F1 and point F are two points on this pin shaft). The distance between F and F1 is L Fpin , the angle between the line connecting point E and point F1 and the X-axis is θ FE , the angle between the line connecting point E and point F1 and the outer wing rod 24 is β, and the angle between the outer wing rod 24 and the X-axis is α;

[0063] The coordinates of point C are: C = (A x +L AC Cosθ A , A y , A z +L AC sinθ A );

[0064] The coordinates of point C1 are: C1 = C + (0, L Cpin , 0) = (A x +L AC cosθ A , A y +L Cpin , A z +L AC sinθ A );

[0065] The coordinates of point G are:

[0066] The distance between point C1 and point G is L C1G , and LC1G 2 = ||G1 - G|| 2 , that is:

[0067] The coordinates of point E are: E = (A x + L AE cosθ A , E y , A z + L AE sinθ A );

[0068] The coordinates of point F1 are: F1 = (F1 x , E y , F1 z ), where

[0069]

[0070] E y = L Fpin ,

[0071]

[0072] The specific calculation of point F1 is as follows:

[0073] Point F1 lies in the same plane as EH (the Y - coordinate is fixed at E v ), and satisfies two conditions: 1. The projected length of the distance from B to F1 in the ZX - plane is L BF1 :

[0074] F1 x 2 + F1 z 2 = L BF1 2

[0075] 2. The projected length of the distance from F1 to E in the ZX - plane is L EF1 :

[0076] (F1 x - E x ) 2 +(F1 z - E z ) 2 = L EF1 2

[0077] These two equations describe two circles projected onto the ZX - plane:

[0078] 1. Circle 1: Center at B, radius L BF1;

[0079] 2. Circle 2: centered at E, with radius L EF1 ;

[0080] By solving the equations of the two circles simultaneously, the equation of the line connecting the intersection points of the two circles can be obtained as E x x + E z z = k

[0081] where K is a constant.

[0082] Since the (X, Z) coordinates of point F1 must satisfy both:

[0083] F1 x 2 + F1 z 2 = L BF1 2 and (2) E x x + E z z = k,

[0084] Let the plane vector E = (E x , E z ); then the line equation can be written as E·(x, z) = k,

[0085] The unit vector of the plane vector E is:

[0086] The modulus of a point P on the line is

[0087] Then the closest point (foot of the perpendicular) P from the line to the origin is:

[0088] where

[0089] Let the unit vector perpendicular to E be

[0090] Then the intersection point of the circle and the line is F1 = P ± hv,

[0091] where

[0092] That is:

[0093] Therefore

[0094]

[0095] Select the appropriate solution for F1 according to the actual design of the mechanism;

[0096] The coordinates of point F are: F = (F1 x , 0, F1z )

[0097] θ EF = atan2(E x - F1 x , E z - F1 z )

[0098] α = θ EF - β

[0099] According to the above design conditions, it can be ensured that the aircraft can operate normally. In the formulas of the above design conditions, the known design parameters are: L AC , L Cpin , R, L C1G , L AE , L Fpin ,, L BF , L EF1 , β, Coordinates of point A: (A x , A y , A z ), Coordinates of point B: (0, 0, 0), Coordinates of point O1: The distance from the connection point of the eccentric shaft and the rotating wheel to point O1 of the rotating wheel 251 is R; therefore, in formula (1), as long as is determined, θ A can be calculated, and according to formula (2) and the calculated θ A , θ EF and α can be obtained; that is, the inner wing angle θ A of the flapping-wing bionic aircraft at any moment in a motion cycle, and the outer wing angle α, are convenient for kinematic analysis of the mechanism, and the dimensions of each part in the mechanism can also be adjusted through this equation to achieve the purpose of quickly adjusting the flapping angle range of the aircraft during the design process.

[0100] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and replacements can be made, and these improvements and replacements should also be regarded as the protection scope of the present invention.

Claims

1. A double-segment flapping-wing bionic aircraft based on a spatial multi-link mechanism, characterized in that: It includes an aircraft body, wings and a driving device. The wings are symmetrically arranged on both sides of the aircraft body. The wing includes an inner wing rod, a track rod, a connecting plate, an outer wing rod and a transmission component. One end of the inner wing rod and one end of the track rod are respectively hinged to the aircraft body. The inner wing rod and the track rod are arranged in a skew and staggered manner. The other end of the inner wing rod and the other end of the track rod are respectively hinged to the connecting plate. One end of the outer wing rod is fixedly connected to the connecting plate. The transmission component includes a rotating wheel and a connecting rod. The rotating wheel is arranged on one side of the aircraft body. An eccentric shaft is arranged on the rotating wheel. The eccentric shaft is ball-jointed to one end of the connecting rod. The other end of the connecting rod is ball-jointed to the inner wing rod. The driving device is installed on the aircraft body and connected to the rotating wheel. The driving device can drive the rotating wheel to rotate at a constant speed.

2. The double-segment flapping-wing bionic aircraft based on a spatial multi-link according to claim 1, wherein: The wing further includes an inner wing auxiliary rod and an outer wing auxiliary rod. The inner wing auxiliary rod is arranged parallel to one side of the inner wing rod. One end of the inner wing auxiliary rod is hinged to the aircraft body. The other end of the inner wing auxiliary rod is hinged to one end of the outer wing auxiliary rod. The outer wing auxiliary rod is parallel to the outer wing rod. An inner wing skeleton rod fixedly connected to the inner wing auxiliary rod is arranged on the side of the inner wing rod. An outer wing skeleton rod fixedly connected to the outer wing auxiliary rod is arranged on the side of the outer wing rod.

3. The double-segment flapping-wing bionic aircraft based on a spatial multi-link according to claim 1, characterized in that: The driving device includes a motor, a driving gear, a reduction gear and a transmission gear. The driving gear is arranged on the output shaft of the motor and meshes with the reduction gear. The transmission gear is coaxially arranged on the reduction gear and meshes with the rotating wheel.

4. The double-segment flapping-wing bionic aircraft based on a spatial multi-link according to claim 3, characterized in that: The motor is installed on one side of the aircraft body. The driving gear and the reduction gear are arranged on the other side of the aircraft body. The output shaft of the motor can rotatably pass through the aircraft body and is connected to the driving gear.

5. The double-segment flapping-wing bionic aircraft based on a spatial multi-link according to claim 4, characterized in that: The transmission gear passes through the aircraft body and meshes with the rotating wheels located on both sides of the aircraft body respectively.

6. The double-segment flapping-wing bionic aircraft based on a spatial multi-link according to claim 1, characterized in that: A first bearing seat and a second bearing seat are arranged on the side of the aircraft body. A first connecting block is detachably connected to the end of the inner wing rod. The first connecting block is hinged to the first bearing seat. The first connecting block is ball-jointed to the connecting rod. A second connecting block is detachably connected to the end of the track rod. The second connecting block is hinged to the second bearing seat.

7. The double-segment flapping-wing bionic aircraft based on a spatial multi-link mechanism according to claim 1, wherein: It further includes a first servo, a servo bracket, a second servo, a tail seat and a tail wing rod. The first servo is installed on one side of the aircraft body. The servo bracket is swingably installed at the tail of the aircraft body. The second servo is installed on the servo bracket. The output end of the first servo is connected to the servo bracket through a transmission mechanism and can drive the servo bracket to swing. The tail seat is installed on the output end of the second servo. The tail wing rod is fixed to the tail seat.

8. The double-segment flapping-wing bionic aircraft based on a spatial multi-link according to claim 7, characterized in that: The transmission mechanism includes a first swing arm, a pull rod, and a second swing arm. One end of the first swing arm is fixedly connected to the output end of the first servo motor. The other end of the first swing arm is hinged to one end of the pull rod. The second swing arm is L-shaped. The middle part of the second swing arm is hinged to the tail of the aircraft body. One end of the second swing arm is hinged to the other end of the pull rod. The servo motor bracket is installed on the other end of the second swing arm.

9. The double-segment flapping-wing bionic aircraft based on a spatial multi-link according to claim 1, characterized in that: The wing meets the following design conditions: A spatial rectangular coordinate system is established with the hinge point of the track rod and the aircraft body as the origin. Among them, the axial direction of the rotating wheel is the X-axis direction, the hinge axis of the track rod and the aircraft body is the Y-axis, the hinge point of the inner wing rod and the aircraft body is point A, the hinge point of the track rod and the aircraft body is point B, a connecting shaft is provided on one side of the inner wing rod, the connecting shaft is ball-jointed with one end of the connecting rod, the connection point of the inner wing rod and the connecting shaft is point C, the ball-joint point of the connecting shaft and the connecting rod is point C1, and the distance between point C and point C1 is L Cpin , the ball-joint point of the connecting rod and the eccentric shaft is point G, the center of the end face of the rotating wheel is point O1, the distance from the connection point of the eccentric shaft and the rotating wheel to point O1 is R, and the rotation angle of the rotating wheel is n is the rotational speed of the rotating wheel, t is time, the hinge point of the inner wing rod and the connecting plate is point E, the hinge point of the track rod and the connecting plate is point F, and the angle between the inner wing rod and the X-axis is θ A , the projection point of point F on the track rod in the Y-axis direction is point F1, and the distance between F and F1 is L Fpin , the angle between the line connecting point E and point F1 and the X-axis is θ FE , the angle between the line connecting point E and point F1 and the outer wing rod is β, and the angle between the outer wing rod and the X-axis is α; The coordinates of point C are: C = (A x + L AC cosθ A , A y , A z + L AC sinθ A ); The coordinates of point C1 are: C1 = C + (0, L Cpin , 0) = (A x + L AC cosθ A , A y + L Cpin , A z + L AC sinθ A ); The coordinates of the G point are: The distance between point C1 and point G is L C1G , and L C1G 2 = ||G1 - G|| 2 , that is: The coordinates of point E are: E = (A x + L AE cosθ A , E y , A z + L AE sinθ A ); The coordinates of point F1 are: F1 = (F1 x , E y , F1 z ), where E y = L Fpin , The coordinates of point F are: F = (F1 x , 0, F1 z ); θ EF = atan2(E x - F1 x , E z - F1 z ); α = θ EF - β.

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