Bionic dual-stage flapping-wing aircraft and flight control method

Abstract

The invention discloses a bionic double-stage flapping wing aircraft and a flight control method. The aircraft comprises a fuselage, a gear transmission mechanism, two groups of outer wings, two groups of inner wings, two crank swing mechanisms, two articulated mechanisms and two flipping mechanisms. The two groups of outer wings, two groups of inner wings, two crank swing mechanisms, two articulated mechanisms and two flipping mechanisms are all arranged relatively and correspond to each other. The gear transmission mechanism comprises a transmission control motor, a first-stage gear set, a second-stage gear set, a driving gear and a passive gear. The transmission control motor is connected to the first-stage gear set, the first-stage gear set and the second-stage gear set are axially distributed and connected to each other, the second-stage gear set is connected to the driving gear, the driving gear is meshed with the passive gear, and the driving gear and the passive gear are respectively connected to the two crank swing mechanisms. The invention can enhance the strength of the entire aircraft, so that in the transmission process, interference can be eliminated, vibration can be reduced, and gear slippage can be prevented.

Description

Technical Field

[0001] The invention relates to a bionic double-stage flapping-wing aircraft and a flight control method, belonging to the technical field of bionic aircraft. Background Art

[0002] Bionic flapping-wing aircraft imitates the flying method of creatures such as birds and insects, and generates lift and power by flapping its wings. It integrates multidisciplinary cross-techniques such as bionics, aerodynamic analysis, mechanical structure analysis, energy, communication, and control, and has great application prospects in the fields of ocean monitoring and post-disaster rescue.

[0003] The mechanical structure design of the bionic two-stage flapping-wing aircraft is based on the analysis of the aircraft's target task and environment, thereby determining the aircraft's performance indicators. Combining the principle of bird flapping-wing flight, the mechanical structure of the bionic two-stage flapping-wing aircraft is designed. In terms of structure, a relatively mature transmission scheme is currently adopted, and the flapping movement of the aircraft's wings in the plane is achieved through two pairs of symmetrically distributed crank swing mechanisms. This mechanism not only has only one degree of freedom, but also the two wings are completely symmetrical during the flapping process to achieve dynamic balance. Compared with fixed-wing and rotary-wing aircraft, the bionic two-stage flapping-wing robot can simultaneously generate the lift and thrust required for flight during a flapping process, with high energy utilization and better maneuverability.

[0004] However, the assembly and debugging of the existing prototypes revealed that the existing prototype models had the following problems during assembly: the design and structure of some parts were not strong enough, resulting in the breakage of parts during transmission. Some parts interfered when they were transmitted to a certain angle. Due to the error between the shaft and the gear, the multi-stage gear transmission caused the error to be amplified and the mechanism to vibrate. Summary of the invention

[0005] The purpose of the present invention is to solve the defects of the above-mentioned prior art and to provide a bionic two-stage flapping-wing aircraft. The aircraft can enhance the strength of the entire aircraft by improving the gear transmission mechanism, so that interference can be eliminated, vibration can be reduced, and gear slippage can be prevented during the transmission process.

[0006] Another object of the present invention is to provide a flight control method, which is implemented based on the above-mentioned bionic double-stage flapping-wing aircraft.

[0007] The purpose of the present invention can be achieved by adopting the following technical solutions:

[0008] A bionic double-stage flapping-wing aircraft comprises a fuselage, a gear transmission mechanism, two sets of outer wings, two sets of inner wings, two crank swing mechanisms, two hinge mechanisms and two flip mechanisms, wherein the two sets of outer wings, the two sets of inner wings, the two crank swing mechanisms, the two hinge mechanisms and the two flip mechanisms are all arranged relatively and correspond to each other one by one.

[0009] Each crank rocking mechanism comprises a rocker, a crank carbon plate, a first transmission rod and a connecting piece, wherein the first transmission rod is connected to the crank carbon plate, the crank carbon plate is connected to the rocker through the connecting piece, and the rocker is connected to the corresponding inner wing; a plurality of evenly distributed through holes are arranged in the circumferential direction of the driving gear and the driven gear, one of the through holes of the driving gear is used as the first through hole, one of the through holes of the driven gear is used as the second through hole, the first through hole is connected to the first transmission rod of one of the crank rocking mechanisms, the second through hole is connected to the first transmission rod of the other crank rocking mechanism, and the positions of the first through hole and the second through hole are symmetrical.

[0010] Furthermore, the first-stage gear set includes a first output gear and a duplex gear, the second-stage gear set includes a second output gear and a secondary gear, the motor shaft of the transmission control motor is connected to the gear shaft of the first output gear, the first output gear is meshed with the duplex gear, the gear shaft of the duplex gear is connected to the second output gear, the second output gear is meshed with the secondary gear, and the gear shaft of the secondary gear is connected to the gear shaft of the driving gear.

[0011] Furthermore, the first output gear and its gear shaft, the duplex gear and its gear shaft, the secondary gear and its gear shaft, the driving gear and its gear shaft, and the driven gear and its gear shaft are all integrated structures.

[0012] Furthermore, each crank rocking mechanism includes a rocker, a pendulum rod, a connecting rod, a first carbon plate, a second carbon plate, a first connecting piece, a second connecting piece and a first transmission rod, the rocker and the pendulum rod are respectively connected to the corresponding inner wings, the rocker is connected to the first carbon plate through the first connecting piece, the pendulum rod is connected to the second carbon plate through the second connecting piece, the first carbon plate and the second carbon plate are respectively hinged to the two ends of the connecting rod, and the first transmission rod is connected to the second carbon plate; a plurality of evenly distributed through holes are arranged in the circumferential direction of the driving gear and the driven gear, one of the through holes of the driving gear is used as the first through hole, one of the through holes of the driven gear is used as the second through hole, the positions of the first through hole and the second through hole are symmetrical, wherein the first through hole is connected to the first transmission rod of one of the crank rocking mechanisms, and the second through hole is connected to the first transmission rod of the other crank rocking mechanism.

[0013] Furthermore, each articulated mechanism includes an articulated carbon plate and two fisheye bearings. The two fisheye bearings are respectively connected to the rocker and the swing arm of the corresponding crank rocking mechanism, and are respectively articulated to the articulated carbon plate. The articulated carbon plate is fixedly connected to the corresponding flipping mechanism.

[0014] Furthermore, each flipping mechanism includes a flipping control servo and a second transmission rod, the flipping control servo is fixedly connected to the articulated carbon plate of the corresponding articulated mechanism, the servo shaft of the flipping control servo is connected to the second transmission rod through a coupling, and the second transmission rod is connected to the corresponding outer wing.

[0015] Furthermore, it also includes a tail wing and a swing mechanism, wherein the swing mechanism is arranged at the rear part of the fuselage and connected to the tail wing.

[0016] Furthermore, the swing mechanism includes two swing control servos and a universal joint, the servo shafts of the two swing control servos are respectively connected to the universal joint, and the universal joint is connected to the tail wing.

[0017] Furthermore, the fuselage, the two sets of outer wings and the two sets of inner wings are all skeleton structures.

[0018] Furthermore, the gear transmission mechanism is printed using aluminum alloy metal.

[0019] Another object of the present invention can be achieved by adopting the following technical solutions:

[0020] A flight control method is implemented based on the above-mentioned bionic two-stage flapping-wing aircraft, and the method includes: using a transmission control motor of a gear transmission mechanism to drive a first-stage gear set, a second-stage gear set, a driving gear and a driven gear to rotate in sequence, so that a crank swing mechanism drives an inner wing to swing, a flip mechanism and an outer wing to make relative motion under the action of a hinge mechanism, and at the same time, the outer wing is flipped by the flip mechanism, and the flip angle of the outer wing is controlled.

[0021] The present invention has the following beneficial effects compared with the prior art:

[0022] 1. The present invention is based on the structural characteristics of the traditional bionic two-stage flapping-wing aircraft and is improved. The gear transmission mechanism adopts an axially distributed two-stage gear set, so that each gear shaft is given an axial constraint, reducing assembly errors and greatly reducing various interferences and adverse conditions that occur in the gear transmission mechanism during the transmission process, such as axial shaking of gears, shaft breakage, and increased gear clearance and slippage.

[0023] 2. In the gear transmission mechanism of the present invention, the gear shafts of the first output gear and the first output gear, the gear shafts of the duplex gears and the duplex gears, the gear shafts of the secondary gears and the secondary gears, the gear shafts of the active gears and the active gears, and the gear shafts of the passive gears and the passive gears are all integrated structures, and the gears and shafts are integrated into one, which eliminates the instability caused by errors after assembling traditional gears and shafts, and also strengthens the strength of the connection between the gears and shafts.

[0024] 3. The gear transmission mechanism of the present invention is printed with aluminum alloy metal, which not only meets the requirements of mechanism transmission in terms of strength, but also has the advantages of wear resistance, small error, and not easy to break. In addition, the quality is almost the same as that of resin or glass fiber printing materials and is not too heavy.

[0025] 4. The present invention improves the stability of the bionic two-stage flapping-wing aircraft structure, making the test results of the physical model closer to the theoretical data, and reduces the number of parts and assembly time required during the assembly of the bionic two-stage flapping-wing aircraft, as well as the assembly process precision requirements, making the product more popular. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0027] Figure 1 It is a three-dimensional structural diagram of a bionic double-stage flapping-wing aircraft according to an embodiment of the present invention.

[0028] Figure 2 It is a front view structural diagram of a bionic two-stage flapping-wing aircraft according to an embodiment of the present invention.

[0029] Figure 3 It is a side structural diagram of a bionic two-stage flapping-wing aircraft according to an embodiment of the present invention.

[0030] Figure 4 This is a top view of the structure of a bionic two-stage flapping-wing aircraft according to an embodiment of the present invention.

[0031] Figure 5 It is a front view structural diagram of the connection between the gear transmission mechanism and the crank rocking mechanism of the bionic two-stage flapping-wing aircraft according to an embodiment of the present invention.

[0032] Figure 6 It is a side structural diagram of the connection between the gear transmission mechanism and the crank rocking mechanism of the bionic two-stage flapping-wing aircraft according to an embodiment of the present invention.

[0033] Figure 7 It is a top view of the connection structure of the gear transmission mechanism and the crank rocking mechanism of the bionic two-stage flapping-wing aircraft in an embodiment of the present invention.

[0034] Figure 8 This is a structural diagram of the connection between the crank swing mechanism, the gear transmission mechanism and the articulated mechanism of the bionic two-stage flapping-wing aircraft according to an embodiment of the present invention.

[0035] Among them, 1-fuselage, 101-first circular frame, 102-second circular frame, 103-third circular frame, 104-semicircular and semi-elliptical plate, 2-gear transmission mechanism, 201-transmission control motor, 202-driving gear, 203-passive gear, 204-first output gear, 205-dual gear, 206-second output gear, 207-secondary gear, 3-outer wing, 4-inner wing, 5-crank swing mechanism, 501 - rocker, 502- rocker arm, 503- connecting rod, 504- first carbon plate, 505- second carbon plate, 506- first connecting piece, 507- second connecting piece, 508- first transmission rod, 6- articulated mechanism, 601- articulated carbon plate, 602- fisheye bearing, 7- flip mechanism, 701- flip control servo, 702- second transmission rod, 8- tail wing, 9- swing mechanism, 901- swing control servo, 902- universal joint. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] Example:

[0038] like Figure 1 to Figure 4 As shown, the present embodiment provides a bionic two-stage flapping-wing aircraft, which includes a fuselage 1, a gear transmission mechanism 2, two groups of outer wings 3, two groups of inner wings 4, two crank rocking mechanisms 5, two articulated mechanisms 6 and two flipping mechanisms 7. The two groups of outer wings 3, the two groups of inner wings 4, the two crank rocking mechanisms 5, the two articulated mechanisms 6 and the two flipping mechanisms 7 are all arranged relatively to the left and right, and are all one-to-one corresponding. Each crank rocking mechanism 5 is connected to the corresponding inner wing 4 and is articulated to the corresponding articulated mechanism 6. Each flipping mechanism 7 is fixedly connected to the corresponding articulated mechanism 6 and is connected to the corresponding outer wing 3. The fuselage 1, the two groups of outer wings 3 and the two groups of inner wings 4 are all skeleton structures.

[0039] like Figure 1 to Figure 7As shown, the gear transmission mechanism 2 is arranged at the fuselage 1, and the transmission ratio is 1 / 15.15, which can convert the motor rotation motion into the plane swing motion of the flapping wing, and includes a transmission control motor 201, a first-stage gear set, a second-stage gear set, a driving gear 202 and a passive gear 203. The transmission control motor 201 is the prime mover of the flapping wing action, the transmission control motor is connected to the first-stage gear set, the first-stage gear set and the second-stage gear set are axially distributed and connected to each other, the second-stage gear set is connected to the driving gear 202, the driving gear 202 is meshed with the passive gear 203, the driving gear 202 is connected to the crank swing mechanism 5 on the right, and the passive gear 203 is connected to the crank swing mechanism 5 on the left, the driving gear 202 and the passive gear 202 have the same number of teeth and module, the driving gear 202 converts the gear transmission into the crank swing motion, and because the driving gear 202 is meshed with the passive gear 203, the symmetrical motion of the double crank swing mechanism 5 can be achieved through the driving gear 202 and the passive gear 203.

[0040] Specifically, the first-stage gear set includes a first output gear 204 and a double gear 205, and the second-stage gear set includes a second output gear 206 and a secondary gear 207. The motor shaft of the transmission control motor 201 is connected to the gear shaft of the first output gear 205, specifically connected to the gear shaft of the first output gear 205 through a fixing bolt, the first output gear 205 is meshed with the double gear 205, the gear shaft of the double gear 205 is connected to the second output gear 206, the second output gear 206 is meshed with the secondary gear 207, the gear shaft of the secondary gear 207 is connected to the gear shaft of the driving gear 202, and the gear shaft of the double gear 205 is connected to the gear shaft of the driving gear 202. The two ends of the shaft are respectively mounted on the first bearing seat and the second bearing seat, the gear shaft of the secondary gear 207 is mounted on the third bearing seat, the gear shaft of the active gear is mounted on the fourth bearing seat, and the gear shaft of the passive gear is mounted on the fifth bearing seat; the transmission control motor 201 rotates to drive the first output gear 205 to rotate, the rotation of the first output gear 205 drives the double gear 205 to rotate, the rotation of the double gear 205 drives the second output gear 206 to rotate, the rotation of the second output gear 206 drives the secondary gear 207 to rotate, the rotation of the secondary gear 207 drives the active gear 202 to rotate, thereby driving the passive gear 203 to rotate.

[0041] In this embodiment, the transmission control motor 201 can adopt a 1500kv Langyu X2206 DC brushless motor, the parameters of the first output gear 205 and the second output gear 206 are i1=19, m=0.5, the parameters of the double gear 205 are i1=73, i2=18, m=0.5, the parameters of the secondary gear 207 are i3=71, m=0.5, and the parameters of the driving gear 202 and the passive gear 203 are i5=31, m=1.125.

[0042] This embodiment changes the traditional three-stage gear transmission scheme in the same plane into an axially distributed two-stage gear transmission. Since the traditional gear transmission is in the same plane, the cross-sectional area of ​​the "bird body" of the bionic aircraft is increased, and the error of multiple gears in the assembly process is amplified, resulting in gear slippage, shaking, etc. during the transmission process. The use of axially distributed gear sets allows each gear shaft to obtain an axial constraint to reduce assembly errors; the gear shafts of the first output gear and the first output gear, the gear shafts of the double gears and the double gears, the gear shafts of the secondary gears and the secondary gears, the gear shafts of the active gears and the active gears, and the gear shafts of the passive gears and the passive gears are all integrated structures. By integrating the gears and shafts, since the traditional gears and shafts are designed and printed separately and then assembled, and each part is small in size and has high precision requirements, it is easy to Affected by the matching error, and the aircraft also has high requirements on the strength of the shaft. The radial force on the shaft is large and it is easy to break. Therefore, this embodiment adopts the form of gear and shaft as one, which eliminates the instability caused by errors after the traditional gear and shaft are assembled, and also strengthens the strength of the connection between the gear and the shaft; the material of the gear transmission mechanism is reselected. Compared with the traditional resin-printed gears, glass fiber-printed shafts, or directly using carbon fiber tubes as shafts, this embodiment uses aluminum alloy metal printing technology to print the structure. Compared with the problems of insufficient strength and easy wear of resin-printed gears, easy breakage of glass fiber-printed shafts, and manual grinding required for carbon fiber tube printing, it can not only meet the needs of mechanism transmission in terms of strength, but also has the advantages of wear resistance, small error, and not easy to break. And the quality is almost the same as that of resin or glass fiber printing materials, and it will not be too heavy.

[0043] like Figures 1 to 8As shown, two crank rocking mechanisms 5 enable the aircraft to imitate the up and down flapping of bird wings and provide power for the flight of the aircraft. Each crank rocking mechanism 5 includes a rocker 501, a pendulum 502, a connecting rod 503, a first carbon plate 504, a second carbon plate 505, a first connecting piece 506, a second connecting piece 507 and a first transmission rod 508. The rocker 501 and the pendulum 502 are respectively connected to the corresponding inner wing 4. The rocker 501 is connected to the first carbon plate 504 through the first connecting piece 506, and the pendulum 502 is connected to the second carbon plate 505 through the second connecting piece 507. The first carbon plate 504 and the second carbon plate 505 are respectively hinged to the connecting rod 503, and the first transmission rod 508 is connected to the second carbon plate 505. In order to connect the driving gear 202 to the crank rocking mechanism 5 on the right, and the driven gear 203 to the crank rocking mechanism 5 on the left, a plurality of evenly distributed through holes are provided in the circumferential direction of the driving gear 202 and the driven gear 203. 02 as the first through hole, and one of the through holes of the passive gear 203 as the second through hole, the positions of the first through hole and the second through hole are symmetrical, wherein the first through hole is connected to the first transmission rod 503 of the left crank rocking mechanism 5, and the second through hole is connected to the first transmission rod 503 of the right crank rocking mechanism 5, and the first transmission rod 503 of the right crank rocking mechanism 5 is driven to rotate by the active gear 202, so that the second carbon plate 505 and the rocking rod 502 of the right crank rocking mechanism 5 swing, thereby making the first carbon plate 504 and the rocking rod 501 of the right crank rocking mechanism 5 rock, and at the same time, the passive gear 203 is affected by the active gear 202, driving the first transmission rod 503 of the left crank rocking mechanism 5 to rotate, so that the second carbon plate 505 and the rocking rod 502 of the left crank rocking mechanism 5 swing, thereby making the first carbon plate 504 and the rocking rod 501 of the left crank rocking mechanism 5 rock, so as to realize the symmetrical movement of the double crank rocking mechanism 5, thereby driving the inner wing 4 to swing.

[0044] Furthermore, each articulated mechanism 6 includes an articulated carbon plate 601 and two fisheye bearings 602, the two fisheye bearings 602 are respectively connected to the rocker 501 and the swing rod 502 of the corresponding crank rocking mechanism 5, and are respectively articulated to the articulated carbon plate 601, and the articulated carbon plate 601 is fixedly connected to the corresponding flipping mechanism 7; each flipping mechanism 7 includes a flipping control servo 701 and a second transmission rod 702, the flipping control servo 701 is fixedly connected to the articulated carbon plate 601 of the corresponding articulated mechanism 6, the servo shaft of the flipping control servo 701 is connected to the second transmission rod 702 through a coupling, and the second transmission rod 702 is connected to the corresponding outer wing 3, the flipping control servo 701, after the crank rocking mechanism 5 drives the inner wing 4 to swing, the flipping mechanism 7 and the outer wing 3 make relative motion under the action of the articulated mechanism 6, and at the same time, the flipping control servo 701 rotates to drive the second transmission rod 702 to flip the outer wing 3 and control the flipping angle of the outer wing 3.

[0045] In order to control the flight direction of the bionic two-stage flapping-wing aircraft, the bionic two-stage flapping-wing aircraft of this embodiment also includes a tail 8 and a swinging mechanism 9. The tail 8 is also a skeleton structure. The swinging mechanism 9 is arranged at the rear of the fuselage 1 and is connected to the tail 8; further, the swinging mechanism includes two swing control servos 901 and a universal joint 902. The servo shafts 901 of the two swing control servos 9 are respectively connected to the universal joint 902, and the universal joint 902 is connected to the tail 8. The two swing control servos 9 rotate to adjust the up, down, left and right directions of the universal joint 902, so that the tail 8 swings up, down, left and right, thereby controlling the flight direction.

[0046] In this embodiment, the gear transmission mechanism 2, the swing mechanism 9 and the two flipping mechanisms 7 can be controlled by a control device. The control device may include a motion controller and three drivers, the motion controller is connected to the three drivers respectively, and the three drivers are connected to the transmission control motor of the gear transmission mechanism 2, the swing control steering gear 901 of the swing mechanism 9, and the flip control steering gear 701 of the two flipping mechanisms 7 respectively.

[0047] Furthermore, the fuselage 1 can support the main shape of the entire aircraft, including a first circular frame 101, a second circular frame 102, a third circular frame 103 and four semicircular and semi-elliptical plates 104. The first circular frame 101 serves as the front part of the fuselage 1, the second circular frame 102 serves as the rear part of the fuselage 1, and the third circular frame 103 and the four semicircular and semi-elliptical plates 104 serve as the middle part of the fuselage 1. The first circular frame 101 is installed on the semicircular and semi-elliptical plates 104 at the front, the second circular frame 102 is installed on the third circular frame 103, and the third circular frame 103 and the four semicircular and semi-elliptical plates 104 serve as the middle part of the fuselage 1. The frame 103 and the four semicircular and semi-elliptical plates 104 are connected by multiple fixing rods, two of which pass through the first carbon plates 504 of the two crank rocking mechanisms 5 respectively; each group of outer wings 3 includes four outer winglets, which are connected by fixing rods; each group of inner wings 4 includes four inner winglets, which are connected by fixing rods, one end of the fixing plate is fixedly connected to the innermost inner winglet, and the other end passes through the outermost inner winglet and is fixedly connected to a fixing seat, which is installed on the rocker 501 of the corresponding crank rocking mechanism 5.

[0048] The flight control principle of the bionic two-stage flapping-wing aircraft of this embodiment is as follows: the transmission control motor of the gear transmission mechanism drives the first-stage gear set, the second-stage gear set, the driving gear and the driven gear to rotate in sequence, so that the crank rocking mechanism drives the inner wing to swing, and the flipping mechanism and the outer wing make relative motion under the action of the hinge mechanism. At the same time, the outer wing is flipped by the flipping mechanism, and the flipping angle of the outer wing is controlled, and the tail wing is controlled to swing up and down and left and right by the swinging mechanism, thereby controlling the flight direction.

[0049] In the description of the present invention, it should be noted that, unless otherwise clearly specified and agreed, the terms "setting", "installation" and "connection" should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] To summarize, the present invention is an improvement based on the structural characteristics of the traditional bionic two-stage flapping-wing aircraft. The gear transmission mechanism adopts an axially distributed two-stage gear set, so that each gear shaft is given an axial constraint, reducing assembly errors and greatly reducing various interferences and adverse conditions that occur in the gear transmission mechanism during the transmission process, such as axial shaking of gears, shaft breakage, increased gear clearance and slippage, etc.

[0051] The above is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and inventive concept of the present invention within the scope disclosed by the present invention, which shall fall within the protection scope of the present invention.

Claims

1. A bionic double-stage flapping-wing aircraft, characterized in that: It includes a fuselage, a gear transmission mechanism, two sets of outer wings, two sets of inner wings, two crank swing mechanisms, two hinge mechanisms and two flip mechanisms, wherein the two sets of outer wings, the two sets of inner wings, the two crank swing mechanisms, the two hinge mechanisms and the two flip mechanisms are all arranged relatively and correspond to each other one by one. Each crank swing mechanism is connected to the corresponding inner wing and is hinged to the corresponding hinge mechanism; each flip mechanism is fixedly connected to the corresponding hinge mechanism and is connected to the corresponding outer wing; the gear transmission mechanism is arranged at the fuselage, and includes a transmission control motor, a first-stage gear set, a second-stage gear set, a driving gear and a passive gear; the transmission control motor is connected to the first-stage gear set; the first-stage gear set and the second-stage gear set are axially distributed and connected to each other; the second-stage gear set is connected to the driving gear; the driving gear is meshed with the passive gear; the driving gear and the passive gear are respectively connected to the two crank swing mechanisms; The first-stage gear set includes a first output gear and a duplex gear, the second-stage gear set includes a second output gear and a secondary gear, the motor shaft of the transmission control motor is connected to the gear shaft of the first output gear, the first output gear is meshed with the duplex gear, the gear shaft of the duplex gear is connected to the second output gear, the second output gear is meshed with the secondary gear, and the gear shaft of the secondary gear is connected to the gear shaft of the driving gear; The first output gear and the gear shaft of the first output gear, the double gear and the gear shaft of the double gear, the secondary gear and the gear shaft of the secondary gear, the driving gear and the gear shaft of the driving gear, and the driven gear and the gear shaft of the driven gear are all integrated structures; Each crank rocking mechanism comprises a rocker, a pendulum, a connecting rod, a first carbon plate, a second carbon plate, a first connecting piece, a second connecting piece and a first transmission rod, wherein the rocker and the pendulum are respectively connected to the corresponding inner wings, the rocker is connected to the first carbon plate through the first connecting piece, the pendulum is connected to the second carbon plate through the second connecting piece, the first carbon plate and the second carbon plate are respectively hinged to the two ends of the connecting rod, and the first transmission rod is connected to the second carbon plate; a plurality of evenly distributed through holes are arranged in the circumferential direction of the driving gear and the driven gear, one of the through holes of the driving gear is used as the first through hole, one of the through holes of the driven gear is used as the second through hole, and the positions of the first through hole and the second through hole are symmetrical, wherein the first through hole is connected to the first transmission rod of one of the crank rocking mechanisms, and the second through hole is connected to the first transmission rod of the other crank rocking mechanism; Each articulated mechanism includes an articulated carbon plate and two fisheye bearings. The two fisheye bearings are respectively connected to the rocker and the swing arm of the corresponding crank rocking mechanism, and are respectively articulated to the articulated carbon plate. The articulated carbon plate is fixedly connected to the corresponding flipping mechanism.

2. The bionic double-stage flapping-wing aircraft according to claim 1, characterized in that: Each flipping mechanism comprises a flipping control steering gear and a second transmission rod, wherein the steering gear shaft of the flipping control steering gear is connected to the second transmission rod through a coupling, and the second transmission rod is connected to the corresponding outer wing.

3. The bionic double-stage flapping-wing aircraft according to claim 1, characterized in that: It also includes a tail wing and a swing mechanism, wherein the swing mechanism is arranged at the rear part of the fuselage and connected with the tail wing.

4. The bionic double-stage flapping-wing aircraft according to claim 3, characterized in that: The swing mechanism comprises two swing control steering gears and a universal joint. The steering gear shafts of the two swing control steering gears are respectively connected to the universal joints, and the universal joint is connected to the tail wing.

5. The bionic double-stage flapping-wing aircraft according to any one of claims 1 to 4, characterized in that: The fuselage, two sets of outer wings and two sets of inner wings are all skeleton structures.

6. The bionic double-stage flapping-wing aircraft according to any one of claims 1 to 4, characterized in that: The gear transmission mechanism is printed with aluminum alloy metal.

7. A flight control method, implemented based on the bionic double-stage flapping-wing aircraft according to any one of claims 1 to 6, characterized in that: The method comprises: driving a first-stage gear set, a second-stage gear set, a driving gear and a driven gear to rotate in sequence through a transmission control motor of a gear transmission mechanism, so that a crank swing mechanism drives an inner wing to swing, a flipping mechanism and an outer wing to perform relative motion under the action of a hinge mechanism, and at the same time, the outer wing is flipped through the flipping mechanism, and the flipping angle of the outer wing is controlled.

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