A variable aircraft based on distributed seamless flexible control surfaces and movable wingtips

Abstract

The present invention discloses a variable aircraft based on distributed seamless flexible control surfaces and movable wingtips, which includes a wing box (1), flexible control surfaces (2), movable wingtips (3), a tail fin (4), a fuselage carbon tube (5), a main landing gear (6), a fuselage (7), a nose landing gear (8), and a power plant (9); the flexible control surfaces (2) are composed of a skin chute (21), a drive motor (22), a drive connecting rod (23), a flexible bending mechanism (24), a sliding skin (25), a fixed skin (26), and a skin transition section (27), and can continuously and smoothly bend during flight to improve the lift-drag ratio of the wing. By adopting different bending strategies, real-time optimization of the wing lift distribution or load distribution can be achieved; the movable wingtips (3) are composed of an outer wing section (31), a root connecting piece (32), an encoder (33), a brushless motor (34), and a reducer (35), and can either be locked during flight to increase the wing aspect ratio or swing freely to reduce the wing load and avoid wingtip stall.

Description

Technical Field

[0001] The present invention belongs to the technical field of aircraft, and relates to a variable aircraft, specifically to a variable aircraft based on distributed seamless flexible control surfaces and movable wingtips. Background Art

[0002] With the continuous development of materials science, control science, and manufacturing, the aviation industry has undergone a huge transformation since its inception. However, current aircraft have not yet achieved the same level of efficient and flexible flight as birds. Birds rely solely on a pair of flexible wings that can deform in real time according to flight conditions to adjust their flight attitude, enabling them to fly at the best efficiency in different flight environments and meet various requirements such as low drag during cruising, high lift and high drag during landing, and asymmetric lift during turning.

[0003] The aerodynamic forces acting on an aircraft in flight directly affect its flight performance, and these forces are determined by the geometric shape. The geometric shape of existing aircraft is generally fixed and cannot change its wing shape like birds to obtain the best aerodynamic characteristics. Therefore, they can only perform specific flights and complete specialized tasks. To meet the flight requirements under different conditions such as cruising, takeoff / landing, and turning, different devices need to be installed on the surface of the rigid wing, such as flaps, ailerons, flaperons, and spoilers. These devices have single functions and low usage efficiency, and the actuation method of the rigid mechanism causes surface discontinuities and gaps at the deflection and transition points of the wing surface, resulting in problems such as low aerodynamic efficiency and high aerodynamic noise.

[0004] A variable aircraft is one that can change its aerodynamic shape during flight, such as wing area, aspect ratio, and sweep angle, and maintain the best performance under different flight conditions. Compared with conventional fixed-wing aircraft, variable aircraft have a wider flight envelope and higher flight efficiency, and can balance multiple mission requirements such as cruising, takeoff / landing, and maneuvering. The design concept and method of variable aircraft are different from those of conventional aircraft, and must consider multi-disciplinary integration and comprehensive optimization design through overall and aerodynamic coordination to ensure good aerodynamic performance under different flight conditions. With the increasing requirements for comprehensive design of aircraft, such as high maneuverability, high flight efficiency, and multi-mission adaptability, variable aircraft that are as efficient and flexible as birds have become a research hotspot in the academic and engineering fields.

[0005] Therefore, the present invention proposes a variable aircraft based on distributed seamless flexible control surfaces and movable wingtips. Summary of the Invention

[0006] The present invention proposes a variable aircraft based on distributed seamless flexible control surfaces and movable wingtips. The distributed seamless flexible control surfaces can keep the wing surface continuous and smooth, improve the pressure distribution on the wing surface, thereby enhancing the aerodynamic efficiency and reducing the aerodynamic noise. The movable wingtips can reduce the wing load, avoid wingtip stall, and improve the flight performance. The variable aircraft of the present invention can change the wing shape in real time through the distributed seamless flexible control surfaces and the movable wingtips according to the collected environmental data, greatly improving the flight efficiency and environmental adaptability. Therefore, it can be widely applied to different fields such as long-endurance loitering reconnaissance, high-intensity material transportation, and large-area land mapping.

[0007] According to one aspect of the present invention, there is provided a variable aircraft based on distributed seamless flexible control surfaces and movable wingtips, characterized by comprising:

[0008] A wing box, flexible control surfaces, movable wingtips, a tail fin, a fuselage carbon tube, a main landing gear, a fuselage, a nose landing gear, and a power plant.

[0009] The wing box is a "D"-shaped hollow-section beam, which is the main load-bearing component of the wing, providing sufficient bending and torsional resistance for the wing, and is also used to maintain the shape of the leading edge of the wing and to mount the flexible control surfaces at the trailing edge;

[0010] The flexible control surfaces include:

[0011] Skin chutes, drive motors, drive linkages, flexible bending mechanisms, sliding skins, fixed skins, and skin transition sections;

[0012] The skin chutes are located at the rear of the wing box and on the upper surface of the wing, used to limit the displacement of the sliding skins so that they can only slide along the wing surface; the drive motors are bolted to the rear of the wing box and inside the wing, and the output shafts of the drive motors are connected to the flexible bending mechanisms through drive linkages, driving the deformation of the flexible bending mechanisms by the rotation of the output shafts; both ends of the drive linkages are respectively bolted to the output shafts of the drive motors and the driving positions of the flexible bending mechanisms; the flexible bending mechanisms are located at the trailing edge of the wing and are deformed by the rotation of the drive motors; the sliding skins are pasted on the upper and lower surfaces of the flexible bending mechanisms and are made of polyethylene terephthalate films, which can bend along with the flexible bending mechanisms to maintain the aerodynamic shape of the trailing edge of the wing; the fixed skins are pasted on the upper surface of the skin chutes and are made of polyethylene terephthalate films, but do not need to slide, used to maintain the aerodynamic shape of the upper surface of the middle part of the wing; the skin transition sections are located between adjacent flexible control surfaces and are pasted on the sliding skins of the two side flexible control surfaces, made of silicone films, having good elasticity, used to eliminate the shear difference generated by the different bending amplitudes of the two side flexible control surfaces and achieve the overall seamless effect of the trailing edge of the wing;

[0013] The movable wingtips include:

[0014] Outer wing segment, root connector, encoder, brushless motor, reducer;

[0015] The outer wing segment is made of carbon fiber material, and is connected to the output shaft of the reducer by bolts through the first lug, and is hinged to the root connector by bolts and bearings through the second lug; the root connector is installed on the outer side of the wing, used to connect the outer wing segment, and install the encoder, brushless motor, and reducer; the encoder is installed on the root connector, used to realize the closed-loop control of the brushless motor; the brushless motor is installed on the root connector, used to provide the power for the rotation of the outer wing segment; the reducer is installed on the root connector, the front end is connected to the brushless motor, and the rear end is connected to the first lug of the outer wing segment through the output shaft of the reducer, used to increase the output torque of the brushless motor and drive the outer wing segment to rotate.

[0016] The wing mainly composed of the wing box, the flexible control surface, and the movable wing tip is installed above the fuselage carbon tube, providing lift for the flight of the aircraft; the fuselage is installed below the fuselage carbon tube, and the inside is used to arrange the flight control, power supply, and on-board computer, etc.; the power device and the tail wing are respectively installed at the front end and the rear end of the fuselage carbon tube, the power device is used to provide the horizontal thrust of the aircraft, and the tail wing is used to provide the trimming moment; the nose landing gear is installed on the fuselage carbon tube behind the power device, used to assist in supporting the aircraft and steering on the ground; the main landing gear is installed at the lower part of the fuselage, used to support the aircraft and bear the main load during takeoff and landing.

[0017] Compared with the existing aircraft, the advantages of the present invention are as follows:

[0018] 1. The distributed seamless flexible control surface realizes continuous bending of the control surface by means of a sliding skin, eliminates the scissor difference between the control surfaces through the skin transition section, realizes the continuous smoothness and complete seamlessness of the wing surface, improves the pressure distribution on the wing surface, and improves the aerodynamic efficiency. Reduces aerodynamic noise;

[0019] 2. The distributed seamless flexible control surface is distributed along the entire span of the trailing edge of the wing, replacing structures such as ailerons and flaps, and simultaneously realizes the functions of ailerons and flaps through the coupled control of roll and lift augmentation. Different camber distribution strategies are executed according to different optimization objectives, with simplified structure and higher efficiency;

[0020] 3. The movable wing tip realizes the locking of the wing tip at a certain angle according to the specified restoring moment or the free swing according to the specified damping magnitude through the brushless motor field-oriented control technology, thereby realizing the control of the wing aspect ratio and the wing root load, enabling the design of the aircraft to take into account both flight efficiency and structural reliability issues;

[0021] 4. The variable aircraft is equipped with different sensors to measure different physical quantities. For example, the attitude angle is measured by a gyroscope, the oncoming flow velocity is measured by a pitot tube, and the wing root load is measured by strain gauges. These data are analyzed in real time and decisions are made to jointly change the wing shape through distributed seamless flexible control surfaces and movable wing tips, greatly improving the flight efficiency and environmental adaptability of the aircraft. Brief Description of the Drawings

[0022] Figure 1 Shows the overall design scheme of a variable aircraft based on distributed seamless flexible control surfaces and movable wing tips according to an embodiment of the present invention;

[0023] Figure 2 Shows the specific structure of a distributed seamless flexible control surface according to an embodiment of the present invention;

[0024] Figure 3 Shows the specific structure of a movable wing tip according to an embodiment of the present invention.

[0025] Reference Signs in the Drawings

[0026]

[0027] Detailed Description of the Embodiment

[0028] The embodiments of the present invention will be described in detail below with reference to the drawings.

[0029] Figure 1 Shows the overall design scheme of a variable aircraft based on distributed seamless flexible control surfaces and movable wing tips according to an embodiment of the present invention. Among them, the wing mainly composed of the wing box 1, flexible control surface 2, and movable wing tip 3 is installed above the fuselage carbon tube 5 to provide lift for the flight of the aircraft; the fuselage 7 is installed below the fuselage carbon tube 5, and the inside is used to arrange the flight control, power supply, and on-board computer, etc.; the power plant 9 and the tail wing 4 are respectively installed at the front end and the rear end of the fuselage carbon tube 5, the power plant is used to provide the horizontal thrust of the aircraft, and the tail wing is used to provide the trimming moment; the nose landing gear 8 is installed on the fuselage carbon tube 5 behind the power plant 9 to assist in supporting the aircraft and steering on the ground; the main landing gear 6 is installed at the lower part of the fuselage 7 to support the aircraft and bear the main load during takeoff and landing.

[0030] Figure 2Shows the specific structure of the distributed seamless flexible rudder surface according to an embodiment of the present invention. Among them, the wing box 1 is the main load-bearing component of the wing, providing sufficient bending and torsional resistance for the wing, and at the same time is also used to maintain the shape of the leading edge of the wing and to install the flexible rudder surface 2 at the trailing edge. The flexible rudder surface 2 includes a skin chute 21, a driving motor 22, a driving link 23, a flexible bending mechanism 24, a sliding skin 25, a fixed skin 26, and a skin transition section 27. The skin chute 21 is located at the rear of the wing box 1 on the upper surface of the wing, used to limit the displacement of the sliding skin 25 so that it can only slide along the wing surface. The driving motor 22 is bolted to the rear of the wing box 1 inside the wing. The output shaft of the driving motor 22 is connected to the flexible bending mechanism 24 through the driving link 23. By rotating the output shaft, the deformation of the flexible bending mechanism 24 is driven. Both ends of the driving link 23 are respectively bolted and hinged to the output shaft of the driving motor 22 and the driving position of the flexible bending mechanism 24. The flexible bending mechanism 24 is located at the trailing edge of the wing and deforms by the rotation of the driving motor 22. The sliding skin 25 is pasted on the upper and lower surfaces of the flexible bending mechanism 24 and is made of polyethylene terephthalate film, which can bend along with the flexible bending mechanism 24 to maintain the aerodynamic shape of the trailing edge of the wing. The fixed skin 26 is pasted on the upper surface of the skin chute 21 and is made of polyethylene terephthalate film, but does not need to slide, and is used to maintain the aerodynamic shape of the upper surface of the middle part of the wing. The skin transition section 27 is located between adjacent flexible rudder surfaces 2 and is pasted on the sliding skins 25 of the two side flexible rudder surfaces 2. It is made of silicone film and has good elasticity, used to eliminate the shear difference generated by the different bending amplitudes of the two side flexible rudder surfaces 2 and achieve the overall seamless effect of the trailing edge of the wing.

[0031] Figure 3 Shows the specific structure of the movable wing tip according to an embodiment of the present invention. Among them, the movable wing tip 3 includes an outer wing section 31, a root connector 32, an encoder 33, a brushless motor 34, and a reducer 35. The outer wing section 31 is made of carbon fiber material and is bolted to the output shaft 351 of the reducer through the first lug 311 and is bolted and hinged to the root connector 32 through the second lug 312. The root connector 32 is installed on the outer side of the wing, used to connect the outer wing section 31, and to install the encoder 33, the brushless motor 34, and the reducer 35. The encoder 33 is installed on the root connector 32, used to achieve the closed-loop control of the brushless motor 34. The brushless motor 34 is installed on the root connector 32, used to provide the power for the rotation of the outer wing section 31. The reducer 35 is installed on the root connector 32, with the front end connected to the brushless motor 34 and the rear end connected to the first lug 311 of the outer wing section 31 through the reducer output shaft 351, used to increase the output torque of the brushless motor 34 and drive the rotation of the outer wing section 31.

[0032] Table 1 shows the relevant parameters of the variable aircraft based on distributed seamless flexible control surfaces and movable wingtips in the embodiments.

[0033] Table 1

[0034] Empty weight 3000g Maximum takeoff weight 6000g Overall length 1382 mm Wingspan 2912 mm Wing chord 265 mm Aspect ratio 11 Wing loading 78 g / dm

Claims

1. A variable aircraft based on a distributed seamless flexible control surface and a movable wing tip, characterized in that Comprising: A wing box (1), which is a "D"-shaped hollow-section beam and is the main load-bearing component of the wing, providing sufficient bending and torsional resistance for the wing. It is also used to maintain the shape of the leading edge of the wing and for installing the flexible trailing-edge control surface (2); The flexible trailing-edge control surface (2), which includes: A skin chute (21), which is located at the rear of the wing box (1) on the upper surface of the wing and is used to limit the displacement of the sliding skin (25) so that it can only slide along the wing surface; A driving motor (22), which is bolted to the rear of the wing box (1) inside the wing. The output shaft of the driving motor (22) is connected to the flexible bending mechanism (24) through a driving link (23), and the deformation of the flexible bending mechanism (24) is driven by the rotation of the output shaft; The driving link (23), whose two ends are respectively bolted and hinged to the output shaft of the driving motor (22) and the driving position of the flexible bending mechanism (24); The flexible bending mechanism (24), which is located at the trailing edge of the wing and deforms by the rotation of the driving motor (22); The sliding skin (25), which is pasted on the upper and lower surfaces of the flexible bending mechanism (24) and is made of polyethylene terephthalate film, can bend along with the flexible bending mechanism (24) to maintain the aerodynamic shape of the trailing edge of the wing; The fixed skin (26), which is pasted on the upper surface of the skin chute (21) and is made of polyethylene terephthalate film, but does not need to slide, and is used to maintain the aerodynamic shape of the upper surface of the middle part of the wing; The skin transition section (27), which is located between adjacent flexible trailing-edge control surfaces (2) and is pasted on the sliding skins (25) of the two-side flexible trailing-edge control surfaces (2). It is made of silicone film and has good elasticity, and is used to eliminate the shear difference generated by the different bending amplitudes of the two-side flexible trailing-edge control surfaces (2) to achieve the overall seamless effect of the trailing edge of the wing; The movable wing tip (3), which includes: The outer wing segment (31), which is made of carbon fiber material, is bolted to the output shaft of the reducer (351) through the first lug (311), and is bolted and hinged to the root connector (32) through the second lug (312); The root connector (32), which is installed on the outer side of the wing and is used to connect the outer wing segment (31), and to install the encoder (33), the brushless motor (34), and the reducer (35); The encoder (33), which is installed on the root connector (32) and is used to achieve the closed-loop control of the brushless motor (34); The brushless motor (34), which is installed on the root connector (32) and is used to provide the power for the rotation of the outer wing segment (31); The reducer (35), which is installed on the root connector (32), is connected to the brushless motor (34) at the front end, and is connected to the first lug (311) of the outer wing segment (31) through the output shaft of the reducer (351) at the rear end, and is used to increase the output torque of the brushless motor (34) to drive the rotation of the outer wing segment (31); The wing, which consists mainly of the wing box (1), the flexible control surface (2), and the movable wing tip (3), is installed above the fuselage carbon tube (5) to provide lift for the flight of the aircraft. The fuselage (7) is installed below the fuselage carbon tube (5), and the inside is used to arrange flight control, power supply, on-board computer, etc. The power plant (9) and the tail wing (4) are respectively installed at the front end and the rear end of the fuselage carbon tube (5). The power plant (9) is used to provide the horizontal thrust of the aircraft, and the tail wing (4) is used to provide the trimming moment. The nose landing gear (8) is installed on the fuselage carbon tube (5) behind the power plant (9) to assist in supporting the aircraft and steering on the ground. The main landing gear (6) is installed at the lower part of the fuselage (7) to support the aircraft and bear the main loads during takeoff and landing.

2. The variable aircraft based on distributed seamless flexible control surfaces and movable wing tips according to claim 1, wherein: There are three groups of flexible control surfaces (2) on each side of the wing. Each group of flexible control surfaces (2) adopts a flexible bending mechanism (24), a sliding skin (25), and a skin transition section (27). The flexible bending mechanism (24) can achieve continuous and smooth deformation, and bear the main aerodynamic force during flight and maintain the cross-sectional shape of the wing. The sliding skin (25) covers the surface of the flexible bending mechanism (24), can bear a certain aerodynamic force and conform to the bending of the flexible bending mechanism (24). The skin transition section (27) eliminates the shear difference generated during the relative movement of different flexible control surfaces (2). The above three ensure the smooth and seamless effect of the wing surface during the bending process, and can improve the air flow separation problem caused by factors such as the discontinuity and non-smoothness of the wing surface. The coordinated actuation of the six groups of flexible control surfaces (2) can achieve the camber distribution strategy for different optimization purposes. By adopting the camber distribution strategy with the aim of making the wing lift distribution as close as possible to the ideal elliptical lift distribution, the induced drag of the aircraft wing can be minimized to improve the flight efficiency. By adopting the camber distribution strategy with the aim of making the proportion of the lift generated by the wing closer to the wing root larger, the structural load at the wing root can be reduced to avoid the problem of excessive wing root load under abnormal flight conditions.

3. The variable aircraft based on distributed seamless flexible control surfaces and movable wing tips according to claim 1, wherein: The movable wing tip (3) adopts the field-oriented control technology of a brushless motor (34) to perform closed-loop control on physical quantities such as the rotation angle, angular velocity, and torque of the outer wing segment (31). According to the requirements of the flight condition of the aircraft, the outer wing segment (31) is locked at a certain angle according to the specified restoring moment or freely swings according to the specified damping magnitude, so as to achieve the purpose of increasing the wing aspect ratio to improve the flight efficiency or controlling the wing root load within a safe range.

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