An airfoil variable camber mechanism based on a flexible hinge and a control method

Abstract

The present invention relates to an airfoil variable camber mechanism based on flexible hinges, a leading-edge deformation mechanism, a wing fixed section, and a trailing-edge deformation mechanism. The leading-edge deformation mechanism is connected to the front end of the wing fixed section, and the trailing-edge deformation mechanism is connected to the rear end of the wing fixed section. The variable-camber airfoil of the present invention is based on three-section flexible hinges and uses a hybrid drive of a shape memory alloy spring and a servo motor, which can achieve independent drive of the leading edge and the trailing edge of the airfoil, and also achieve the goal of high load-carrying capacity while ensuring large deformation, and can also achieve precise control.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and particularly to an airfoil variable camber mechanism and a control method based on a flexible hinge. Background Art

[0002] The invention of the airplane has greatly affected people's travel modes. Over the years, researchers have been improving airplanes to pursue better aerodynamic performance. Traditional fixed-wing aircraft design their aerodynamic layout and shape according to specific flight missions and environments. At a certain design point, their flight performance is relatively good. Once the environment changes, the aircraft will deviate from the design point and its performance will decline accordingly. With the continuous improvement of performance requirements for aircraft in border patrol, environmental monitoring, and military needs, etc., traditional fixed-wing aircraft cannot meet these requirements. Therefore, variable camber wings have emerged. A variable camber wing refers to a wing that contains a leading edge and a trailing edge that can be bent and changed within a certain range, with a continuous, smooth wing surface without slits or sliding joints; various control devices are installed inside the wing to enable it to change with the environment and match the best aerodynamic efficiency, saving energy. Compared with traditional fixed-wing aircraft using flaps, variable camber wings have no slotted ducts and scissor cuts at the leading and trailing edges of the wing, with continuous curvature changes, gentle wing surface pressure changes, and no obvious flow separation, which can effectively reduce noise. Therefore, variable camber wings are more in line with the development needs of future aircraft.

[0003] The earliest variable camber wing to appear was of a mechanical structure, but it had problems such as the complexity of structure and assembly and weight, thus limiting its research and development and being difficult to meet the needs of low-speed / small aircraft with limited space and sensitive to weight. Subsequently, people designed flexible variable camber wings based on the problems existing in mechanical structure variable camber wings. Currently, existing flexible structures have advantages such as light weight, simple structure and manufacturing, and no need for assembly and lubrication. However, this kind of structure generally has a poor load-bearing capacity, a small degree of deformability, and cannot achieve precise control, which greatly affects the performance of variable camber wings. Summary of the Invention

[0004] The purpose of the present invention is to provide a variable leading and trailing edge airfoil structure design based on a flexible hinge to solve the problems that previous flexible variable camber wings have a poor load-bearing capacity, a small degree of deformability, and cannot achieve precise control. The variable camber airfoil of the present invention is based on a three-section flexible hinge, and uses a shape memory alloy spring and a servo motor for hybrid drive, which can realize the respective drive of the leading edge and the trailing edge of the airfoil, and also achieve the goal of having a high load-bearing capacity while ensuring large deformation, and can also achieve precise control.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An airfoil variable camber mechanism based on a flexible hinge, including a leading-edge deformation mechanism, a wing fixed section, and a trailing-edge deformation mechanism. The leading-edge deformation mechanism is connected to the front end of the wing fixed section, and the trailing-edge deformation mechanism is connected to the rear end of the wing fixed section;

[0007] The leading-edge deformation mechanism includes a leading edge, an upper shape memory alloy spring, an upper connecting wire, a lower connecting wire, a lower shape memory alloy spring, and a spring fixing seat. The leading edge is connected to the wing fixed section through a flexible hinge three. The upper shape memory alloy spring is in a contracted state in the initial state. When it is electrified, one end of the upper shape memory alloy spring is fixed on the spring fixing seat, and the other end is connected to the upper connecting wire. The upper connecting wire passes through the upper circular inclined hole one, then passes through the upper circular straight hole two, then turns back and passes through the upper circular inclined hole one, and winds back and forth in an S shape between the upper circular straight hole two and the upper circular inclined hole one, and finally is fixed on the upper circular straight hole two. The upper circular inclined hole one and the upper circular straight hole one are arranged on the upper side of the rear part of the leading edge, and the upper circular straight hole two is arranged on the upper side of the front part of the wing fixed section. The lower shape memory alloy spring is in the longest stretched state in the initial state. When it is not electrified, one end of the lower shape memory alloy spring is fixed on the spring fixing seat, and the other end is connected to the lower connecting wire. The lower connecting wire passes through the lower circular inclined hole one, then passes through the lower circular straight hole two, then turns back and passes through the lower circular inclined hole one, and winds back and forth in an S shape between the lower circular straight hole two and the lower circular inclined hole one, and finally is fixed on the lower circular straight hole two. The lower circular inclined hole one and the lower circular straight hole one are arranged on the lower side of the rear part of the leading edge, and the lower circular straight hole two is arranged on the lower side of the front part of the wing fixed section. When the upper shape memory alloy spring and the lower shape memory alloy spring are electrified, they will contract and drive the leading edge to deflect relative to the wing fixed section;

[0008] The trailing edge deformation mechanism includes a digital servo, an upper drive wire, trailing edge one, trailing edge two, flexible hinge one, flexible hinge two, and a lower drive wire. The wing fixed section is connected to trailing edge one through flexible hinge two, and trailing edge one is connected to trailing edge two through flexible hinge one. The digital servo is placed in the internal cavity of the wing fixed section, and a circular rotating disk is connected to the output shaft of the digital servo; one end of the upper drive wire is wound and fixed in the upper hole of the circular rotating disk, and the other end passes through the upper circular inclined hole two and is led out from the upper hole at the rear side of the wing fixed section, then passes through the upper circular straight hole four, then turns back and passes through the upper circular straight hole three, winds back and forth in an S shape between the upper circular straight hole four and the upper circular straight hole three, then passes through the upper circular inclined hole three, then passes through the upper circular straight hole six, then turns back and passes through the upper circular straight hole five, winds back and forth in an S shape between the upper circular straight hole six and the upper circular straight hole five, and finally is fixed on the upper circular straight hole six; the upper circular inclined hole two and the upper circular straight hole three are arranged on the upper rear side of the wing fixed section, the upper circular straight hole four is arranged on the upper front side of trailing edge one, the upper circular inclined hole three and the upper circular straight hole five are arranged on the lower rear side of trailing edge one, and the upper circular straight hole six is arranged on the upper front side of trailing edge two; one end of the lower drive wire is wound and fixed in the lower hole of the circular rotating disk, and the other end passes through the lower circular inclined hole two and is led out from the lower hole at the rear side of the wing fixed section, then passes through the lower circular straight hole four, then turns back and passes through the lower circular straight hole three, winds back and forth in an S shape between the lower circular straight hole four and the lower circular straight hole three, then passes through the lower circular inclined hole three, then passes through the lower circular straight hole six, then turns back and passes through the lower circular straight hole five, winds back and forth in an S shape between the lower circular straight hole six and the lower circular straight hole five, and finally is fixed on the lower circular straight hole six; the lower circular inclined hole two and the lower circular straight hole three are arranged on the lower rear side of the wing fixed section, the lower circular straight hole four is arranged on the lower front side of trailing edge one, the lower circular inclined hole three and the lower circular straight hole five are arranged on the lower rear side of trailing edge one, and the lower circular straight hole six is arranged on the lower front side of trailing edge two; by controlling the digital servo to drive the circular rotating disk to rotate, the upper drive wire and the lower drive wire wound on the circular rotating disk will pull trailing edge one and trailing edge two to deflect.

[0009] Furthermore, the flexible hinge three is an approximately H-shaped structure. The front side of the flexible hinge three is fixed to the rear side of the leading edge through mechanical cooperation of bolts and nuts, and the rear side of the flexible hinge three is fixed to the front side of the wing fixed section through mechanical cooperation of bolts and nuts.

[0010] Furthermore, the flexible hinge two is an approximately H-shaped structure. The front side of the flexible hinge two is fixed to the rear side of the wing fixed section through mechanical cooperation of bolts and nuts, and the rear side of the flexible hinge two is fixed to the front side of trailing edge one through mechanical cooperation of bolts and nuts.

[0011] Furthermore, the flexible hinge one is an approximately H-shaped structure. The front side of the flexible hinge one is fixed to the rear side of trailing edge one through mechanical cooperation of bolts and nuts, and the rear side of the flexible hinge one is fixed to the front side of trailing edge two through mechanical cooperation of bolts and nuts.

[0012] Furthermore, the upper shape memory alloy spring and the lower shape memory alloy spring are made of nickel-titanium alloy material.

[0013] Compared with the prior art, the advantages of the present invention are as follows:

[0014] (1) The present invention uses flexible hinges to connect the various sections of the wing, which is different from the traditional deformation method relying on material properties and can achieve a large range of changes in the leading and trailing edges of the wing.

[0015] (2) The present invention adopts the method of manufacturing the airfoil by 3D printing with resin material. The middle of the airfoil is designed with a hollow structure, which minimizes the weight of the airfoil. The leading edge is driven by a shape memory spring - wire, and the trailing edge is driven by a servo - wire, with a simple structure and space saving.

[0016] (3) The leading edge is driven by two sections of shape memory alloy springs, and the trailing edge is driven by a servo, ensuring that the variable camber airfoil can withstand a very large load.

[0017] (4) The present invention uses STM32 as the control board. Through programming, precise control of the trailing edge of the wing can be achieved, enabling it to change with the changes in the external environment.

[0018] (5) The solution of the present invention is reasonable, with a simple structure and easy to implement, and can separately control the leading edge and the trailing edge respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the front view of the airfoil variable camber mechanism based on flexible hinges;

[0020] Figure 2 is the three - dimensional structure schematic diagram of the airfoil variable camber mechanism based on flexible hinges;

[0021] Figure 3 is the three - dimensional structure view of flexible hinge three;

[0022] Figure 4 is the three - dimensional structure view of flexible hinge two;

[0023] Figure 5 is the three - dimensional structure view of flexible hinge one;

[0024] Figure 6 is the contour diagram of the maximum deformation position that the leading edge can reach;

[0025] Figure 7 is the contour diagram of the maximum deformation position that the trailing edge can reach;

[0026] In the figure: 1. leading edge, 2. upper shape memory alloy spring, 3. upper connecting wire, 4. wing fixed section, 5. digital servo, 6. upper driving wire, 7. trailing edge one, 8. trailing edge two, 9. flexible hinge one, 10. flexible hinge two, 11. lower driving wire, 12. flexible hinge three, 13. lower connecting wire, 14. lower shape memory alloy spring, 15. spring fixing seat, 16. bolt hole, 17. upper circular inclined hole one, 18. upper circular straight hole one, 19. upper circular straight hole two, 20. upper circular inclined hole two, 21. upper circular straight hole three, 22. upper circular straight hole four, 23. upper circular inclined hole three, 24. upper circular straight hole five, 25. upper circular straight hole six, 26. lower circular straight hole six, 27. lower circular straight hole five, 28. lower circular inclined hole three, 29. lower circular straight hole four, 30. lower circular straight hole three, 31. lower circular inclined hole two, 32. lower circular straight hole two, 33. lower circular straight hole one, 34. lower circular inclined hole one. Specific implementation mode

[0027] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but it is not intended to limit the present invention.

[0028] As Figures 1 to 7 shown, an airfoil variable camber mechanism based on a flexible hinge, a leading edge deformation mechanism, a wing fixed section 4, and a trailing edge deformation mechanism. The leading edge deformation mechanism is connected to the front end of the wing fixed section 4, and the trailing edge deformation mechanism is connected to the rear end of the wing fixed section 4;

[0029] The leading edge deformation mechanism includes a leading edge 1, an upper shape memory alloy spring 2, an upper connecting wire 3, a lower connecting wire 13, a lower shape memory alloy spring 14, and a spring fixing seat 15. The leading edge 1 is connected to the wing fixed section 4 through a flexible hinge three 12. The upper shape memory alloy spring 2 is in a contracted state in its initial state. When it is energized, one end of the upper shape memory alloy spring 2 is fixed on the spring fixing seat 15, and the other end is connected to the upper connecting wire 3. The upper connecting wire 3 passes through the upper circular inclined hole one 17, then passes through the upper circular straight hole two 19, then turns back and passes through the upper circular straight hole one 18, winds back and forth in an S shape between the upper circular straight hole two 19 and the upper circular straight hole one 18, and finally is fixed on the upper circular straight hole two 19. The upper circular inclined hole one 17 and the upper circular straight hole one 18 are arranged on the upper side of the rear part of the leading edge 1, and the upper circular straight hole two 19 is arranged on the upper side of the front part of the wing fixed section 4. The lower shape memory alloy spring 14 is in a stretched state to its longest in its initial state. When it is not energized, one end of the lower shape memory alloy spring 14 is fixed on the spring fixing seat 15, and the other end is connected to the lower connecting wire 13. The lower connecting wire 13 passes through the lower circular inclined hole one 34, then passes through the lower circular straight hole two 32, then turns back and passes through the lower circular straight hole one 33, winds back and forth in an S shape between the lower circular straight hole two 32 and the lower circular straight hole one 33, and finally is fixed on the lower circular straight hole two 32. The lower circular inclined hole one 34 and the lower circular straight hole one 33 are arranged on the lower side of the rear part of the leading edge 1, and the lower circular straight hole two 32 is arranged on the lower side of the front part of the wing fixed section 4. When the upper shape memory alloy spring 2 and the lower shape memory alloy spring 14 are energized, they will contract and drive the leading edge 1 to deflect relative to the wing fixed section 4;

[0030] The trailing edge deformation mechanism includes a digital servo 5, an upper drive wire 6, a trailing edge one 7, a trailing edge two 8, a flexible hinge one 9, a flexible hinge two 10, and a lower drive wire 11. The wing fixed section 4 is connected to the trailing edge one 7 through the flexible hinge two 10, and the trailing edge one 7 is connected to the trailing edge two 8 through the flexible hinge one 9. The digital servo 5 is placed in the internal cavity of the wing fixed section 4. The cavity is rectangular, and a circular rotating disc is connected to the output shaft of the digital servo 5. One end of the upper drive wire 6 is wound and fixed in the upper hole of the circular rotating disc, and the other end passes through the upper circular inclined hole two 20 and is led out from the upper hole at the rear side of the wing fixed section 4. Then it passes through the upper circular straight hole four 22, then turns back and passes through the upper circular straight hole three 21, and winds back and forth in an S shape between the upper circular straight hole four 22 and the upper circular straight hole three 21. Then it passes through the upper circular inclined hole three 23, then through the upper circular straight hole six 25, then turns back and passes through the upper circular straight hole five 24, and winds back and forth in an S shape between the upper circular straight hole six 25 and the upper circular straight hole five 24, and finally is fixed on the upper circular straight hole six 25. The upper circular inclined hole two 20 and the upper circular straight hole three 21 are arranged on the upper side of the rear part of the wing fixed section 4, the upper circular straight hole four 22 is arranged on the upper side of the front part of the trailing edge one 7, the upper circular inclined hole three 23 and the upper circular straight hole five 24 are arranged on the upper side of the rear part of the trailing edge one 7, and the upper circular straight hole six 25 is arranged on the upper side of the front part of the trailing edge two 8. One end of the lower drive wire 11 is wound and fixed in the lower hole of the circular rotating disc, and the other end passes through the lower circular inclined hole two 31 and is led out from the lower hole at the rear side of the wing fixed section 4. Then it passes through the lower circular straight hole four 29, then turns back and passes through the lower circular straight hole three 30, and winds back and forth in an S shape between the lower circular straight hole four 29 and the lower circular straight hole three 30. Then it passes through the lower circular inclined hole three 28, then through the lower circular straight hole six 26, then turns back and passes through the lower circular straight hole five 27, and winds back and forth in an S shape between the lower circular straight hole six 26 and the lower circular straight hole five 27, and finally is fixed on the lower circular straight hole six 26. The lower circular inclined hole two 31 and the lower circular straight hole three 30 are arranged on the lower side of the rear part of the wing fixed section 4, the lower circular straight hole four 29 is arranged on the lower side of the front part of the trailing edge one 7, the lower circular inclined hole three 28 and the lower circular straight hole five 27 are arranged on the lower side of the rear part of the trailing edge one 7, and the lower circular straight hole six 26 is arranged on the lower side of the front part of the trailing edge two 8. By controlling the digital servo 5 to drive the circular rotating disc to rotate, the upper drive wire 6 and the lower drive wire 11 wound on the circular rotating disc will pull the trailing edge one 7 and the trailing edge two 8 to deflect.

[0031] Furthermore, the flexible hinge three 12 is of an approximate H-shaped structure. The front side of the flexible hinge three 12 is fixed to the rear side of the leading edge 1 through mechanical cooperation of bolts and nuts, and the rear side of the flexible hinge three 12 is fixed to the front side of the wing fixed section 4 through mechanical cooperation of bolts and nuts.

[0032] Further, the flexible hinge II 10 is of an approximate H-shaped structure. The front side of the flexible hinge II 10 is fixed to the rear side of the wing fixed section 4 through mechanical cooperation of a bolt and a nut, and the rear side of the flexible hinge II 10 is fixed to the front side of the trailing edge I 7 through mechanical cooperation of a bolt and a nut.

[0033] Further, the flexible hinge I 9 is of an approximate H-shaped structure. The front side of the flexible hinge I 9 is fixed to the rear side of the trailing edge I 7 through mechanical cooperation of a bolt and a nut, and the rear side of the flexible hinge I 9 is fixed to the front side of the trailing edge II 8 through mechanical cooperation of a bolt and a nut.

[0034] Further, the upper shape memory alloy spring 2 and the lower shape memory alloy spring 14 are made of nickel-titanium alloy material.

[0035] Through programming, the STM32 single-chip microcomputer is used to control the digital servo 5 to drive the circular rotating disk to rotate. The upper driving wire 6 and the lower driving wire 11 wound around the circular rotating disk will pull the trailing edge I 7 and the trailing edge II 8. At the same time, the trailing edge I 7 is connected to the wing fixed section 4 through the flexible hinge II 10, and the trailing edge II 8 is connected to the trailing edge I 7 through the flexible hinge I 9. In this way, the variable camber of the trailing edge is realized, and the precise control of the airfoil variable camber is achieved. The trailing edge I 7 is of a thin-wall structure with a wall thickness of 1 - 3 mm, which can reduce the weight as much as possible while ensuring the strength, and its internal cavity is trapezoidal. The trailing edge II 8 is of a thin-wall structure with a wall thickness of 1 - 3 mm, which can reduce the weight as much as possible while ensuring the strength, and its internal cavity is triangular.

[0036] The working process of the present invention is as follows:

[0037] The leading edge 1 is initially in a horizontal position. At this time, the lower shape memory alloy spring 14 is stretched to the longest state, and the upper shape memory alloy spring 2 is energized and contracted to the shortest state. Because the upper shape memory alloy spring 2 is continuously energized and in the shortest state at this time, it can withstand a relatively large downward deflection load and remain in place. The load can reach more than 6 times the weight of the airfoil itself. Because the lower shape memory alloy spring 14 is stretched to the longest state at this time, it can withstand a relatively large upward deflection load and remain in place. The load can reach more than 10 times the weight of the airfoil. Energize the lower shape memory alloy spring 14 and cut off the power supply of the upper shape memory alloy spring 2. The leading edge 1 deflects counterclockwise to a fixed position under the contraction action of the lower shape memory alloy spring 14. At this time, the upper shape memory alloy spring 2 is stretched to the longest state, so it can withstand a relatively large load that generates tension on it. The load can reach more than 10 times the weight of the airfoil itself. At this time, the lower shape memory alloy spring 14 is energized and contracted to the shortest state, and it can withstand a relatively large load that generates tension on it. The load can reach more than 6 times the weight of the airfoil without rotating.

[0038] Power off the lower shape memory alloy spring 14 and power on the upper shape memory alloy spring 2. Under the action of the upper shape memory alloy spring 2, the leading edge 1 deflects clockwise and returns to the horizontal position.

[0039] The first trailing edge 7 and the second trailing edge 8 are initially both in the horizontal position. At this time, the digital servo 5 is in the reset state, the upper drive line 6 and the lower drive line 11 are both straightened, and the first trailing edge 7 and the second trailing edge 8 will not deflect under the action of external forces and remain in the horizontal position. At this time, the maximum load that can be borne is up to 10 times its own weight. When the digital servo 5 rotates clockwise, the distance between the fixed winding point of the lower drive line 11 on the circular rotating disk and the lower circular inclined hole 31 will become farther, while the fixed winding point of the upper drive line 6 on the circular rotating disk will rotate clockwise with the circular rotating disk and the distance from the upper circular inclined hole 20 will become closer. At this time, the lower drive line 11 is in a stressed state and drives the first trailing edge 7 to deflect with the flexible hinge 2 as the base point, and the second trailing edge 8 deflects with the flexible hinge 1 as the base point, so that the whole airfoil generates continuous rotation. At this time, the lower drive line 11 is in a relatively tight stretched state, and it can bear a relatively large upward load, up to 16 times the weight of the airfoil itself without changing its position. The upper drive line 6 can also bear a relatively large tensile force to ensure that the airfoil remains in position when bearing a relatively large downward load, and the maximum load can reach 10 times the weight of the airfoil itself. During the downward deflection process, the flexible hinge 1 and the flexible hinge 2 will undergo relatively large deformations. Because of the existence of the hinges, the airfoil can achieve a relatively large range of deflection, and the maximum vertical displacement of the right endpoint of the second trailing edge 8 can reach 1 / 5 of the length of the airfoil itself. In this process, a program is written into the STM32 single-chip microcomputer in advance, and the angle of rotation of the circular rotating disk of the digital servo 5 can be accurately controlled by inputting values using the upper computer software, so as to accurately control the deflection of the trailing edge of the airfoil. When the digital servo 5 is adjusted to rotate counterclockwise through the upper computer software, the winding point of the upper drive line 6 on the circular rotating disk will move away from the upper circular inclined hole 20, generating a tensile force on the upper drive line 6. At the same time, the winding point of the lower drive line 11 on the circular rotating disk will approach the lower circular inclined hole 31. In this way, the upper drive line 6 is in a stressed state and drives the first trailing edge 7 to return to the horizontal position with the flexible hinge 2 as the base point, and the second trailing edge 8 returns to the horizontal position with the flexible hinge 1 as the base point.

[0040] The above is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be able to realize that all equivalent replacements and obvious changes made by using the description and illustration content of the present invention should be included in the protection scope of the present invention.

Claims

1. An airfoil variable camber mechanism based on a flexible hinge, characterized in that, a leading-edge deformation mechanism, a wing fixed section (4), and a trailing-edge deformation mechanism, wherein the leading-edge deformation mechanism is connected to the front end of the wing fixed section (4), and the trailing-edge deformation mechanism is connected to the rear end of the wing fixed section (4); the leading-edge deformation mechanism includes a leading edge (1), an upper shape memory alloy spring (2), an upper connecting line (3), a lower connecting line (13), a lower shape memory alloy spring (14), and a spring fixing seat (15). The leading edge (1) is connected to the wing fixed section (4) through a flexible hinge three (12). The upper shape memory alloy spring (2) is in a contracted state in the initial state. When it is electrified, one end of the upper shape memory alloy spring (2) is fixed on the spring fixing seat (15), and the other end is connected to the upper connecting line (3). The upper connecting line (3) passes through the upper circular inclined hole one (17), then passes through the upper circular straight hole two (19), then turns back and passes through the upper circular straight hole one (18), and winds back and forth in an S shape between the upper circular straight hole two (19) and the upper circular straight hole one (18), and finally is fixed on the upper circular straight hole two (19). The upper circular inclined hole one (17) and the upper circular straight hole one (18) are arranged on the upper side of the rear part of the leading edge (1), and the upper circular straight hole two (19) is arranged on the upper side of the front part of the wing fixed section (4). The lower shape memory alloy spring (14) is in the longest state in the initial state. When it is not electrified, one end of the lower shape memory alloy spring (14) is fixed on the spring fixing seat (15), and the other end is connected to the lower connecting line (13). The lower connecting line (13) passes through the lower circular inclined hole one (34), then passes through the lower circular straight hole two (32), then turns back and passes through the lower circular straight hole one (33), and winds back and forth in an S shape between the lower circular straight hole two (32) and the lower circular straight hole one (33), and finally is fixed on the lower circular straight hole two (32). The lower circular inclined hole one (34) and the lower circular straight hole one (33) are arranged on the lower side of the rear part of the leading edge (1), and the lower circular straight hole two (32) is arranged on the lower side of the front part of the wing fixed section (4). When the upper shape memory alloy spring (2) and the lower shape memory alloy spring (14) are electrified, they will contract, driving the leading edge (1) to deflect relative to the wing fixed section (4); The trailing edge deformation mechanism includes a digital servo (5), an upper drive wire (6), a trailing edge one (7), a trailing edge two (8), a flexible hinge one (9), a flexible hinge two (10), and a lower drive wire (11). The wing fixed section (4) is connected to the trailing edge one (7) through the flexible hinge two (10), and the trailing edge one (7) is connected to the trailing edge two (8) through the flexible hinge one (9). The digital servo (5) is placed in the internal cavity of the wing fixed section (4), and a circular rotating disc is connected to the output shaft of the digital servo (5). One end of the upper drive wire (6) is wound and fixed in the upper hole of the circular rotating disc, and the other end passes through the upper circular inclined hole two (20) and is led out from the upper hole at the rear side of the wing fixed section (4), then passes through the upper circular straight hole four (22), then turns back and passes through the upper circular straight hole three (21), winds back and forth in an S shape between the upper circular straight hole four (22) and the upper circular straight hole three (21), then passes through the upper circular inclined hole three (23), then passes through the upper circular straight hole six (25), then turns back and passes through the upper circular straight hole five (24), winds back and forth in an S shape between the upper circular straight hole six (25) and the upper circular straight hole five (24), and finally is fixed on the upper circular straight hole six (25). The upper circular inclined hole two (20) and the upper circular straight hole three (21) are arranged on the upper rear side of the wing fixed section (4), the upper circular straight hole four (22) is arranged on the upper front side of the trailing edge one (7), the upper circular inclined hole three (23) and the upper circular straight hole five (24) are arranged on the upper rear side of the trailing edge one (7), and the upper circular straight hole six (25) is arranged on the upper front side of the trailing edge two (8). One end of the lower drive wire (11) is wound and fixed in the lower hole of the circular rotating disc, and the other end passes through the lower circular inclined hole two (31) and is led out from the lower hole at the rear side of the wing fixed section (4), then passes through the lower circular straight hole four (29), then turns back and passes through the lower circular straight hole three (30), winds back and forth in an S shape between the lower circular straight hole four (29) and the lower circular straight hole three (30), then passes through the lower circular inclined hole three (28), then passes through the lower circular straight hole six (26), then turns back and passes through the lower circular straight hole five (27), winds back and forth in an S shape between the lower circular straight hole six (26) and the lower circular straight hole five (27), and finally is fixed on the lower circular straight hole six (26). The lower circular inclined hole two (31) and the lower circular straight hole three (30) are arranged on the lower rear side of the wing fixed section (4), the lower circular straight hole four (29) is arranged on the lower front side of the trailing edge one (7), the lower circular inclined hole three (28) and the lower circular straight hole five (27) are arranged on the lower rear side of the trailing edge one (7), and the lower circular straight hole six (26) is arranged on the lower front side of the trailing edge two (8). By controlling the digital servo (5) to drive the circular rotating disc to rotate, the upper drive wire (6) and the lower drive wire (11) wound on the circular rotating disc will pull the trailing edge one (7) and the trailing edge two (8) to deflect.

2. The flexible hinge-based airfoil camber-changing mechanism according to claim 1, characterized in that, The flexible hinge three (12) is of an approximate H-shaped structure. The front side of the flexible hinge three (12) is fixedly mounted on the rear side of the leading edge (1) through mechanical cooperation of bolts and nuts, and the rear side of the flexible hinge three (12) is fixedly mounted on the front side of the wing fixed section (4) through mechanical cooperation of bolts and nuts.

3. The airfoil camber-changing mechanism based on a flexible hinge according to claim 1, characterized in that, the flexible hinge two (10) is of an approximate H-shaped structure. The front side of the flexible hinge two (10) is fixedly mounted on the rear side of the wing fixed section (4) through mechanical cooperation of bolts and nuts, and the rear side of the flexible hinge two (10) is fixedly mounted on the front side of the trailing edge one (7) through mechanical cooperation of bolts and nuts.

4. The airfoil camber-changing mechanism based on a flexible hinge according to claim 1, characterized in that, the flexible hinge one (9) is of an approximate H-shaped structure. The front side of the flexible hinge one (9) is fixedly mounted on the rear side of the trailing edge one (7) through mechanical cooperation of bolts and nuts, and the rear side of the flexible hinge one (9) is fixedly mounted on the front side of the trailing edge two (8) through mechanical cooperation of bolts and nuts.

5. The airfoil camber-changing mechanism based on a flexible hinge according to claim 1, characterized in that, the upper shape memory alloy spring (2) and the lower shape memory alloy spring (14) are made of nickel-titanium alloy material.

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