Aircraft and aircraft performance optimization method

Abstract

The invention belongs to the technical field of aircrafts, and particularly relates to an aircraft and an aircraft performance optimization method.The aircraft comprises a fuselage, wings installed on the two sides of the fuselage and an empennage installed at the tail of the fuselage; a wheel leg structure for walking and obstacle crossing is mounted at the front end of the abdomen of the machine body; each wing comprises a folding frame, a main framework, an auxiliary framework and a wing surface, hinge seats are arranged on the two sides of the front end of the folding frame, hinge holes connected with the hinge seats are formed in one end of the main framework, and the other end of the main framework is far away from the hinge seats and serves as a free end; the two or more auxiliary frameworks are rotationally connected to the side, close to the rear end of the folding frame, of the main framework. In the application, based on the driving of the winders and the ropes, the control on the extension and folding of the wings is realized, and the structure is relatively light; and the structure can realize secondary folding of the wings, and then through cooperation of the wheel leg structures, walking and obstacle crossing of the aircraft are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft, and in particular relates to an aircraft and an aircraft performance optimization method. Background Art

[0002] Most common small drones carry a certain load to fly to the target area to perform tasks. Therefore, for small drones, their mission envelope is relatively simple, and there is no other way to move except flying. However, in some scenarios, drones are required to walk, overcome obstacles, etc.; for the two states of drones, flying and crawling: the requirements for the shape of the aircraft may be very different. In the crawling state, the drone needs to have a smaller cross-sectional size, which is suitable for moving in a small space. The flying state requires the aircraft to have an aerodynamic shape with high lift and low resistance, so the aircraft needs to have a sufficient wingspan. The use of a foldable wing design can solve the above problems well. When maneuvering on the ground, the wings are folded to reduce the lateral size, and when flying, the wings are unfolded to ensure good aerodynamics.

[0003] Common wing folding mechanisms are mostly used to fold the wings to reduce the size for easy transportation or launch through special mechanisms. It is sufficient to ensure the strength of the wing root and the stability of the unfolding process. In addition, the folding method of common small drones is automatic unfolding. There is no special mechanism for secondary folding, or it is difficult to take into account the lightweight requirements of the aircraft when adding such special mechanisms; improvement is necessary. Summary of the invention

[0004] The purpose of the present invention is to provide an aircraft and an aircraft performance optimization method to solve the problem that the wing folding mechanism of the existing aircraft cannot perform secondary folding well when adapting to the crawling and flying states, or the mechanism is not light enough.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows: In a first aspect, an aircraft comprises a fuselage, wings mounted on both sides of the fuselage, and a tail mounted at the tail of the fuselage; a wheel-leg structure for walking and overcoming obstacles is mounted at the front end of the belly of the fuselage; The wing comprises a folding frame, a main frame, a secondary frame and an airfoil, both sides of the front end of the folding frame are provided with hinge seats, one end of the main frame is provided with a hinge hole connected to the hinge seat, the other end of the main frame is away from the hinge seat as a free end, and two or more secondary frames are respectively rotatably connected to the rear end side of the main frame close to the folding frame; the airfoil is symmetrically covered on the folding frame, the main frame and the secondary frame, and the airfoil is composed of a skin made of a flexible material; The free end of the main frame is connected with a first rope and a second rope. The first rope passes through the front side of the main frame, enters from the front end of the folding frame, and is connected to a first reel; the second rope passes through the middle of the secondary frame at the rear side of the main frame in sequence, and then enters from the rear end of the folding frame, and is connected to a second reel; the first reel is operated to pull the wing to unfold through the first rope, and the second reel is operated to pull the wing to fold through the second rope. When the first reel is reeled, the second reel is unreeled, and when the second reel is reeled, the first reel is unreeled, which has high stability.

[0006] In the present application, when the aircraft is in flight, the extended wings provide lift to achieve cruising; and when the wings are fully extended, the wing subframes are fan-shaped, which has a good effect on the lateral and vertical shaping of the wings. When the aircraft is walking (or crawling) or overcoming obstacles, the wheel-leg structure and the wings are used to achieve driving, and it has good obstacle-crossing performance. In addition, the structure composed of a rope and a reel is relatively light while ensuring the reeling function; and it can well follow the deformation of the wings; the extension and folding process is relatively smooth, and it is not easy to affect the flight state of the aircraft.

[0007] Furthermore, the outer edges of the wing surfaces between the main frame and the secondary frame, and between adjacent secondary frames are set as inner concave edges. With such a structural design, the improved wing reduces the wing area of ​​the aircraft, and has great improvements in flight time, flight controllability, flight noise, etc.

[0008] Furthermore, the sub-frame is provided with an open slot, and a third rope is connected to one end of the open slot away from the hinge hole. The third rope extends toward the corresponding hinge hole and then passes through the folding frame and enters the folding frame, and is connected to a third reel; the third reel is actuated to pull the end of the sub-frame to bend to a specified angle through the third rope.

[0009] Among them, the method of setting the open slot can further reduce the weight of the wing and maintain sufficient support for the wing surface; by setting the third reel and the third rope, the deformation of the wing surface can be more conveniently controlled to achieve the corresponding flight attitude adjustment purpose, such as the roll control of the wing.

[0010] Furthermore, a mounting ear is provided on the main frame on the side of the hinge hole, and the mounting ear is provided with a through hole for the third rope to pass through.

[0011] Furthermore, the free end of the main frame is also connected to the third rope connected to the third winder, and when the third winder pulls the end of the secondary frame to bend through the third rope, the free end of the main frame is pulled to bend synchronously. In this way, the main frame can be controlled to follow the deformation of the secondary frame, and the deformation of the entire wing can be controlled more consistently; the wing can be deformed smoothly, the actuator is greatly simplified, and the flight performance is improved.

[0012] Furthermore, the folding frame includes a frame body, a hinge shaft is installed on the front inner wall of the frame body, the hinge shaft cooperates with the hinge hole of the sub-frame, and an end cover for limiting the hinge shaft is installed on the front outer wall of the frame body to form the hinge seat.

[0013] Furthermore, a winding roller for winding up the first rope and the second rope is installed in the middle part of the rear end of the frame body, and the winding roller is connected to the servo gear to form the first winder or the second winder; the frame body can be first installed on the fuselage in a left-right symmetrical manner, and then the main frame and the auxiliary frame at both ends are connected; finally, the skin is covered to realize the installation of the wing.

[0014] In a second aspect, an aircraft performance optimization method is provided for the aircraft as described above, the method comprising: According to the set design parameters of the aircraft, an aircraft model is established to solve the aerodynamic coefficients of the aircraft; Based on the calculated aerodynamic coefficients of the aircraft, the driving power of the aircraft is selected, wherein the driving power of the aircraft can be characterized by the motor power and the force efficiency of the propeller; Analyze the torque of the propeller and conduct data verification to compare the anti-torque characteristics of different propellers; The final motor and propeller are selected based on the comparison results.

[0015] Furthermore, the method also includes: when solving the aerodynamic coefficient of the aircraft, estimating the aerodynamic coefficient of the aircraft using a vortex lattice method.

[0016] In the present application, through the aircraft performance optimization method, the wings, tail and drive structure of the aircraft can be simulated and analyzed more accurately and at a low cost, and suitable wings and drive mechanisms can be selected to meet the design requirements.

[0017] The invention adopting the above technical solution has the following advantages: In this application, the wheel-leg structure of the aircraft can provide good ground maneuverability and obstacle crossing ability, so that the aircraft can quickly leave the risk area in some scenarios; the wing adopts a flexible wing foldable design, and has the ability to take off again by itself. In addition, the structure that controls the folding of the wing is mainly composed of ropes and reels, which are small and lightweight in structure. The reel can be set inside the fuselage to make the best use of the internal space of the aircraft and realize the reasonable distribution of the aircraft mass, thereby improving the stability, control performance and lightweight level of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings; Figure 1 It is a structural schematic diagram of an aircraft of the present invention; Figure 2 A schematic diagram of a simulated structure of a wing in an embodiment of an aircraft of the present invention; Figure 3 The structure of the wing of an aircraft embodiment of the present invention is shown in FIG. Figure 1 ; Figure 4 The structure of the wing of an aircraft embodiment of the present invention is shown in FIG. Figure 2 ; Figure 5 for Figure 4 The enlarged schematic diagram of point A in the middle; Figure 6 A bottom view of a wing in an embodiment of an aircraft of the present invention; Figure 7 A schematic diagram of the structure of a folding frame in an aircraft embodiment of the present invention Figure 1 ; Figure 8 A schematic diagram of the structure of a folding frame in an aircraft embodiment of the present invention Figure 2 ; Fig. 9 A schematic diagram of the deformation principle of the wing in an embodiment of an aircraft of the present invention; Fig.10 It is a structural schematic diagram of a reverse torsion test bench of the present invention; Fig.11 A schematic diagram of the testing principle of a reverse torsion test bench of the present invention; Fig.12 It is a structural schematic diagram of a wheel-leg structure in an aircraft embodiment of the present invention; Fig.13 A schematic diagram of a flow chart of an aircraft performance optimization method of the present invention; The main component symbols are described as follows: 101. Fuselage; 102. Wing; 103. Tail; 104. Wing edge; 105. Folding frame; 106. Main frame; 107. Auxiliary frame; 108. Articulated seat; 109. Articulated hole; 110. First threading hole; 111. Auxiliary frame hinge end; 112. Connecting plate; 113. Mounting ear; 114. Limiting plate; 115. Opening slot; 116. Frame body; 117. Winder; 118. Winding servo; 119. Towing part; 120. Test bench base; 121. Lever; 122. Test shaft; 123. Test blade; 130. Wheel leg structure; B. Second threading hole; C. Third threading hole; D. Fourth threading hole; E. Fifth threading hole. DETAILED DESCRIPTION

[0019] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that in the drawings or descriptions of the specification, similar or identical parts use the same figure numbers, and the implementation methods not shown or described in the drawings are forms known to ordinary technicians in the relevant technical field. In addition, the directional terms mentioned in the embodiments, such as "upper", "lower", "top", "bottom", "left", "right", "front", "back", etc., are only referenced to the directions of the drawings and are not used to limit the scope of protection of the present invention. Example 1

[0020] like Figures 1 to 4 As shown, an aircraft according to an embodiment of the present invention comprises a fuselage 101, wings 102 installed on both sides of the fuselage 101, and a tail 103 installed at the tail of the fuselage 101; a wheel-leg structure 130 for walking and overcoming obstacles is installed at the front end of the belly of the fuselage 101, and the structure of the wheel-leg structure 130 can refer to Fig.12 The wheel-leg structure 130 mainly includes a wheel axle, which is mounted on the front end of the belly of the fuselage 101 through a bearing, and wheel legs mounted on both ends of the wheel axle, wherein the wheel legs are three L-shaped legs distributed in a circle around the central axis of the wheel axle; an obstacle-crossing servo for driving the wheel axle to rotate can be installed inside the fuselage 101; The wing 102 includes a folding frame 105, a main frame 106, a sub-frame 107 and an airfoil. Both sides of the front end of the folding frame 105 are provided with hinge seats 108. One end of the main frame 106 is provided with a hinge hole 109 connected to the hinge seat 108. The other end of the main frame 106 is away from the hinge seat 108 as a free end. The three sub-frames 107 are respectively rotatably connected to the rear end side of the main frame 106 close to the folding frame 105. The airfoil is symmetrically covered on the folding frame 105, the main frame 106 and the sub-frame 107, and the airfoil is composed of a skin made of a flexible material. Among them, the flexible material can be tarpaulin.

[0021] In fact, in this embodiment, according to design requirements, flexible materials such as plastic film, glass fiber, etc. can also be selected to manufacture the skin; in addition, when setting the wheel legs, a landing gear can be installed at the rear end of the belly of the fuselage 101, and running wheels can be installed on the landing gear, thereby enhancing the ability of the aircraft to adapt to more scenarios.

[0022] In this embodiment, the free end of the main frame 106 is connected with a first rope and a second rope. The first rope passes through the front side of the main frame 106, enters from the front end of the folding frame 105, and is connected to a first reel; the second rope passes through the middle of the sub-frame 107 on the rear side of the main frame 106 in sequence, and then enters from the rear end of the folding frame 105, and is connected to a second reel; the first reel is operated to pull the wing 102 to unfold through the first rope, and the second reel is operated to pull the wing 102 to fold through the second rope. When the first reel is reeled, the second reel is unreeled, and when the second reel is reeled, the first reel is unreeled. The coordinated traction of the first reel and the second reel ensures the extended state of the wing, and the stability is high.

[0023] In the present application, when the aircraft is in flight, the extended wings provide lift to achieve cruising; and when the wings are fully extended, the wing subframes are fan-shaped, which has a good effect on the lateral and vertical shaping of the wings. When the aircraft is walking (or crawling) or overcoming obstacles, the wheel-leg structure and the wings are used to achieve driving, and it has good obstacle-crossing performance. In addition, the structure composed of a rope and a reel is relatively light while ensuring the reeling function; and it can well follow the deformation of the wings; the extension and folding process is relatively smooth, and it is not easy to affect the flight state of the aircraft.

[0024] like Figure 2 , Figure 3 As shown, in this embodiment, the outer edges of the airfoils between the main skeleton 106 and the auxiliary skeleton 107 and between adjacent auxiliary skeletons 107 are set as concave edges.

[0025] The main frame 106 and the auxiliary frame 107 are distributed in a fan shape when the wing 102 is fully unfolded, and can play a role in fixing in the horizontal and vertical directions. Figure 3 As shown in the concave arc wing edge 104, although the improved wing 102 reduces the wing area of ​​the aircraft, it is found after flight tests that the wing 102 has great improvements in flight time, flight controllability, flight noise, etc.

[0026] like Figure 3 As shown, in this embodiment, the main frame 106 and the sub-frame 107 are made of carbon fiber sheets as the support of the wing 102, which can prevent the deformation of the wing 102 from being too large, while satisfying the certain adaptive ability of the wing 102 as a flexible wing.

[0027] like Figures 3 to 6 As shown, in this embodiment, the sub-frame 107 is provided with an open slot 115, and the end of the open slot 115 away from the hinge hole 109 is connected to a third rope, and the third rope extends to the corresponding hinge hole 109 and then passes through the folding frame 105 into the folding frame 105, and is connected to a third reel; the third reel acts to pull the end of the sub-frame 107 to bend to a specified angle through the third rope. The value of can be set according to actual conditions, and can be referred to Fig. 9 .

[0028] In fact, the adaptive deformation of the sub-skeleton 107 can also be achieved as follows: a winding servo 118 is installed at one end of the sub-skeleton 107, and the output shaft of the winding servo 118 is fixedly connected to a rotating rod, and the end of the rotating rod is connected to a traction member 119. The traction member can be a connecting rod, and the other end of the connecting rod is connected to the other end of the sub-skeleton 107. In this way, the sub-skeleton 107 is bent by pulling the winding servo 118, the rotating rod and the connecting rod.

[0029] The main frame 106 in this embodiment is also similar to the shape of the sub-frame 107; a connecting rib is provided in the middle of the opening groove 115 of the sub-frame 107, and a first threading hole 110 is provided on the wall of the opening groove 115 outside the connecting rib; a second threading hole B is provided on the outside of the main frame 106, and the first rope passes through the second threading hole B on the front side of the main frame 106, and is inserted into the front end of the folding frame 105 to connect to the first reel; the second rope passes through the first threading hole 110 in the middle of the sub-frame 107 in turn, and is then inserted into the rear end of the folding frame 105 to connect to the second reel; the first reel is actuated by pulling the wing 102 to extend through the first rope, and the second reel is actuated by folding the wing 102 through the second rope.

[0030] When there are three sub-frames 107, three corresponding connecting plates 112 are arranged on the rear side of the main frame 106, and connecting holes are provided on the connecting plates 112; a notch is processed at the end of the sub-frame 107 to form a sub-frame hinge end 111, and a hinge hole is also processed at the sub-frame hinge end 111, and the hinge hole is connected with the connecting hole through the hinge hole to realize the hinge connection between the sub-frame 107 and the main frame 106. A mounting ear 113 is arranged on the main frame 106 on the side of the hinge hole, and a through hole is provided in the mounting ear 113 for the third rope to pass through. The through hole can relatively limit the pulling direction of the third rope when the wing 102 is deformed and pulled; in fact, the mounting ear 113 where the through hole is located can be arranged perpendicular to the sub-frame 107.

[0031] In addition, in order to more easily limit the folding angle of the wing 102, a limit plate 114 can be set at the hinged end 111 of the secondary frame. When the secondary frame 107 rotates a certain angle, the limit plate 114 abuts against the main frame 106; the rotation angle of the secondary frame 107 is limited by utilizing the position interference of the limit plate 114 and the main frame 106.

[0032] The way of setting the open slot 115 in this embodiment can further reduce the weight of the wing 102 and maintain sufficient support for the wing surface of the wing 102; through the third reel and the third rope, the deformation of the wing surface of the wing 102 can be more conveniently controlled to achieve the corresponding flight attitude adjustment purpose, such as the roll control of the wing.

[0033] In this embodiment, the free end of the main frame 106 is also connected to a third rope connected to the third winder. When the third winder pulls the end of the auxiliary frame 107 to bend through the third rope, the free end of the main frame 106 is pulled to bend synchronously. In this way, the main frame 106 can be controlled to follow the deformation of the auxiliary frame 107, and the deformation of the entire wing 102 can be controlled more consistently; the wing 102 can be deformed smoothly, the actuator is greatly simplified, and the flight performance of the aircraft is improved.

[0034] like Figure 7 , Figure 8 As shown, the folding frame 105 includes a frame body 116, a hinge shaft is installed on the inner wall of the front end of the frame body 116, and the hinge shaft cooperates with the hinge hole of the auxiliary frame 107. The end cover of the limited hinge shaft is installed on the outer wall of the front end of the frame body 116 to form a hinge seat 108. In this embodiment, a winding roller for winding the first rope and the second rope is installed in the middle of the rear end of the frame body 116, and the winding roller is connected to the steering gear. The winding roller and the steering gear constitute a reel 117. When there are two reels 117, they constitute the first reel and the second reel; the frame body 116 can be first installed on the fuselage 101 in a bilaterally symmetrical manner, and then the main frame 106 and the auxiliary frame 107 at both ends are connected; finally, the skin is covered to realize the installation of the wing 102.

[0035] In this embodiment, a third threading hole C and a fourth threading hole D are formed on the top of the frame body 116 for the first rope and the third rope to pass through; a fifth threading hole E is formed on the bottom of the frame body 116 for the second rope to pass through; three winding rollers can be installed, and specifically can be installed on the frame body 116 through a rotating shaft; a driving servo for driving the rotating shaft and the winding roller to rotate can also be installed on the frame body 116; and, in order to ensure that the center of gravity of the wing 102 is evenly distributed, a counterweight can be installed on part of the rotating shaft to balance the center of gravity of the frame body 16. Example 2

[0036] like Fig.13 As shown, in this embodiment, an aircraft performance optimization method is used for the aircraft as described above, and the method includes: S101: Building an aircraft model to solve the aerodynamic coefficients of the aircraft according to the set design parameters of the aircraft; S102: Based on the calculated aerodynamic coefficient of the aircraft, selecting a driving power of the aircraft, wherein the driving power of the aircraft can be characterized by motor power and propeller force efficiency; S103: Analyze the torque of the propeller, and perform data verification and comparison on the anti-torsion characteristics of different propellers; S104: Select the final motor and propeller according to the comparison result.

[0037] Among them, for the aircraft, the initial design parameters set are specifically shown in Table 1 below.

[0038] Table 1 shows the initial design objectives of the aircraft.

[0039] Afterwards, the solidworks software platform was used to build the aircraft model and determine the design parameters of the aircraft, as shown in Table 2. Fluent software was used to solve the aerodynamic coefficients of the aircraft based on the design parameters of the aircraft.

[0040] Table 2 shows the design parameters of the aircraft

[0041] The aerodynamic parameters of the aircraft include level flight state parameters, such as level flight speed, lift coefficient, drag coefficient, and level flight angle of attack, as shown in Table 3.

[0042] Table 3 is the level flight state parameters of the aircraft

[0043] In this embodiment, through the aircraft performance optimization method, the wings and tail of the aircraft can be simulated and analyzed more accurately and at low cost, and suitable wings and drive mechanisms can be selected to meet the design requirements. In addition, for the power of the aircraft, a motor and a propeller are selected to drive. In fact, an inner rotor brushless motor can be selected as the motor.

[0044] Since the propeller generates a counter-torque during high-speed rotation, the counter-torque is due to the conservation of angular momentum of the object. When the propeller and the rotor of the motor rotate at high speed, a torque of equal magnitude and opposite to the rotation direction will be generated on the fuselage 101; ignoring the circumferential air resistance during the rotation of the propeller, its counter-torque can be approximately expressed as: , where: m is the propeller mass, r is the propeller radius, is the angular velocity of propeller rotation. From the above qualitative analysis, it can be seen that the reverse torque of the propeller is proportional to its mass, the square of the propeller radius, and the angular velocity of rotation. For a small UAV or aircraft with a wingspan of 60cm and a thrust of about 500g, there are three main types of propellers suitable for use. The specific parameters are shown in Table 4 below; Table 4 is a comparison table of three propellers

[0045] In this embodiment, Fig.10 , Fig.11 As shown, in order to better obtain the anti-torsion characteristics of different propellers, an anti-torsion test bench is set up, including a test bench base 120, a test shaft 122 rotatably connected to the test bench base 120, the middle part of the test shaft 122 is fixedly installed on the middle part of the lever arm 121, both ends of the lever arm 121 extend downward, a pressure sensor is arranged at the bottom of one end, a test motor is connected to one end of the test shaft, a test blade 123 is coaxially installed on the test motor, the power of the test motor is known, and the performance of different test blades 123 is tested; the test blade 123 is one of the three propellers, and the most suitable propeller is selected through experiments.

[0046] Where M is the counter torque generated by the propeller and the motor outer rotor, the length of the cantilever is L, in mm, and F is the pressure applied to the pressure sensor by the force arm. The relationship between the variables is as follows: ; Among them, F can be collected by the pressure sensor.

[0047] The data obtained from the test are shown in Table 5 below; Table 5 shows the test data of three propellers

[0048] Through theoretical analysis and experiments, it can be seen that at the same speed, the reverse torque of the 5045 three-blade propeller is significantly smaller than that of the other two propellers; therefore, the 5045 propeller is selected as the power propeller of the aircraft.

[0049] In this embodiment, the method further includes: when solving the aerodynamic coefficient of the aircraft, estimating the aerodynamic coefficient of the aircraft by using the vortex lattice method.

[0050] Among them, the vortex grid method can be implemented by Tornado software. The wing surface is divided into several grids, and each grid is defined by data such as span, root chord length, tip chord length, inner torsion angle, outer torsion angle, and sweep angle. Therefore, for this aircraft, the aircraft needs to be parameterized. Taking wing 102 as an example, the half wing of the wing is divided into seven parts, and each part is approximated by a trapezoid. Similarly, the tail wing also adopts the same method and is parameterized by Tornado software and then output.

[0051] This embodiment provides an aircraft, and based on the aircraft, provides an aircraft performance optimization method. The aircraft can provide good ground maneuverability and obstacle crossing ability through the wheel-leg structure, so that the aircraft can quickly leave the risk area in some scenarios; the wing adopts a flexible wing foldable design, and has the ability of self-takeoff for a second time. In addition, the structure for controlling the folding of the wing is mainly composed of ropes and a winder, which is small and lightweight in structure. The winder can be set inside the fuselage to make the best use of the internal space of the aircraft, and realize the reasonable distribution of the aircraft mass, thereby improving the stability, control performance and lightweight level of the aircraft.

[0052] The above is a detailed introduction to an aircraft and an aircraft performance optimization method provided by the present invention. The description of the specific embodiment is only used to help understand the method and its core idea of ​​the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. An aircraft, comprising a fuselage (101), wings (102) mounted on both sides of the fuselage (101), and a tail (103) mounted at the tail of the fuselage (101); characterized in that: A wheel-leg structure (130) for walking and overcoming obstacles is installed at the front end of the belly of the fuselage (101); The wing (102) comprises a folding frame (105), a main frame (106), a secondary frame (107) and an airfoil, both sides of the front end of the folding frame (105) are provided with hinge seats (108), one end of the main frame (106) is provided with a hinge hole (109) connected to the hinge seat (108), the other end of the main frame (106) is away from the hinge seat (108) as a free end, and more than two secondary frames (107) are respectively rotatably connected to the rear end side of the main frame (106) close to the folding frame (105); the airfoil is symmetrically covered on the folding frame (105), the main frame (106) and the secondary frame (107), and the airfoil is composed of a skin made of a flexible material; The free end of the main frame (106) is connected to a first rope and a second rope, the first rope passes through the front side of the main frame (106), penetrates from the front end of the folding frame (105), and is connected to a first reel; the second rope sequentially passes through the middle of the sub-frame (107) on the rear side of the main frame (106), penetrates from the rear end of the folding frame (105), and is connected to a second reel; the first reel is actuated to pull the wing (102) to unfold through the first rope, and the second reel is actuated to pull the wing (102) to fold through the second rope.

2. The aircraft according to claim 1, characterized in that The outer edges of the wing surfaces between the main frame (106) and the auxiliary frame (107) and between adjacent auxiliary frames (107) are arranged as concave edges.

3. The aircraft according to claim 1, characterized in that: The sub-frame (107) is provided with an open slot (115), and one end of the open slot (115) away from the hinge hole (109) is connected to a third rope. The third rope extends toward the corresponding hinge hole (109), passes through the folding frame (105), enters the folding frame (105), and is connected to a third reel. The third reel is actuated to pull the end of the sub-frame (107) to bend to a specified angle through the third rope.

4. The aircraft according to claim 3, characterized in that A mounting ear (113) is provided on the main frame (106) on the side of the hinge hole (109), and the mounting ear (113) is provided with a through hole for the third rope to pass through.

5. The aircraft according to claim 3, characterized in that: The free end of the main frame (106) is also connected to the third rope connected to the third reel, and when the third reel is actuated to pull the end of the secondary frame to bend through the third rope, the free end of the main frame (106) is simultaneously pulled to bend.

6. The aircraft according to claim 1, characterized in that: The folding frame (105) comprises a frame body (116), a hinge shaft is installed on the inner wall surface of the front end of the frame body (116), the hinge shaft cooperates with the hinge hole (109) of the sub-frame (107), and an end cover for limiting the hinge shaft is installed on the outer wall surface of the front end of the frame body (116) to form the hinge seat (108).

7. The aircraft according to claim 6, characterized in that A winding roller for winding up the first rope and the second rope is installed at the middle of the rear end of the frame body (116); the winding roller is connected to a steering gear through a transmission mechanism to form the first winder or the second winder.

8. An aircraft performance optimization method, used for an aircraft as claimed in any one of claims 1 to 7, characterized in that: The method comprises: According to the set design parameters of the aircraft, an aircraft model is established to solve the aerodynamic coefficients of the aircraft; Based on the calculated aerodynamic coefficients of the aircraft, the driving power of the aircraft is selected, wherein the driving power of the aircraft can be characterized by the motor power and the force efficiency of the propeller; Analyze the torque of the propeller and conduct data verification to compare the anti-torque characteristics of different propellers; The final motor and propeller are selected based on the comparison results.

9. The method according to claim 8, characterized in that The method further comprises: when solving the aerodynamic coefficient of the aircraft, estimating the aerodynamic coefficient of the aircraft by using a vortex lattice method.

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