A swift-like variable-shape flapping-wing aircraft and control method thereof

Abstract

The present invention discloses a swift-like variable-shape flapping-wing aircraft, comprising a fuselage support and wings and tail wings mounted on the fuselage support; the fuselage support is also equipped with a flapping-wing driving device, a dive-sweep device, a wing variable-curvature control device and a tail pitch control device that match the wings and tail wings; wherein the flapping-wing driving device is used to drive the wings to complete flapping movements; the dive-sweep device is used to control the effects of the wing and tail sweep; the wing variable-curvature control device is used to change the curvature of the wing by controlling the position of the trailing edge of the wing; and the tail pitch control device is used to control the pitch of the tail wing. By using the present invention, the flapping-wing aircraft has a gliding cruise mode, a dive mode and a climbing mode, and can improve endurance, climbing efficiency and maneuverability through multi-shape switching.

Description

Technical Field

[0001] The invention relates to the technical field of bionic flying devices, and in particular to a swift-like variable-shape flapping-wing aircraft and a control method thereof. Background Art

[0002] In nature, almost all flying creatures use flapping wings to fly. Existing studies on the flight methods of birds and insects have shown that flapping wing flight has better aerodynamic efficiency than fixed-wing and rotary-wing flight at low speeds, and has better capabilities in short-distance takeoff and landing, hovering, etc.

[0003] The bionic flapping-wing aircraft is a new concept aircraft that imitates the flying style of birds or insects. Due to its advantages such as good maneuverability, low noise and good concealment, it has broad application prospects in military, civilian and other fields.

[0004] For example, a Chinese patent document with publication number CN214729656U discloses a flapping-wing aircraft, including a fuselage, wings, a flapping-wing device for driving the wing to flap, and a tail rudder mechanism for controlling the flight state; the tail rudder mechanism includes a tail wing, the tail of the tail wing extends to both sides like the wing, the starting part of the tail wing forms a rotating shaft inserted into a servo fixed on the fuselage, and the servo is connected to a control circuit board and a battery arranged on the fuselage.

[0005] A Chinese patent document with publication number CN109502020A discloses a flapping-wing aircraft for science and education demonstration and an operating method thereof, comprising a fuselage, a driving mechanism, a rotating platform, a control element, a power supply, flapping wings and a tail; the flapping wings are mounted on the driving mechanism, the driving mechanism, the control element, the power supply and the tail are all mounted on the fuselage in a certain manner, and the fuselage and the rotating platform are fixedly connected together; the power supply supplies energy for the entire system, the control element mainly controls the coordinated action of the tail and the rotating platform, and the driving mechanism drives the flapping wings to flap reciprocatingly up and down.

[0006] However, the existing flapping-wing aircraft scheme has the following shortcomings:

[0007] Bird flight can generally be summarized into three forms: gliding, climbing, and diving. Existing design solutions basically work in a single form, and there is rarely any discussion on complex flight states such as switching between different modes of aircraft.

[0008] In addition, as one of the fastest flying birds, the swift's aerodynamic shape, flying style and other technologies are of extremely high reference value, and there are currently no mature patents or related technologies. Summary of the invention

[0009] In order to overcome the above-mentioned defects in the prior art, the present invention provides a swift-like variable-morphology flapping-wing aircraft and a control method thereof, which can improve endurance, increase climbing efficiency and increase maneuverability.

[0010] A swift-like variable-shape flapping-wing aircraft, comprising a fuselage support and wings and a tail installed on the fuselage support;

[0011] The fuselage bracket is also equipped with a flapping wing driving device, a dive sweep device, a wing camber control device and a tail pitch control device that cooperate with the wing and the tail;

[0012] Among them, the flapping-wing drive device is used to drive the wing to complete the flapping movement; the dive-sweep device is used to control the sweep effect of the wing and the tail; the wing variable curvature control device is used to change the curvature of the wing by controlling the position of the trailing edge of the wing; the tail pitch control device is used to control the pitch of the tail.

[0013] Further, the flapping-wing drive device comprises a first brushless motor, a reduction gear set, a crank connector, a connecting rod and a sleeve;

[0014] The first brushless motor and the reduction gear set are both fixed on the fuselage bracket; the output end of the first brushless motor is connected to the driving gear of the reduction gear set, and the driven gear of the reduction gear set is connected to the crank connectors arranged on both sides of the fuselage bracket, and each crank connector is hinged to the sleeve through a connecting rod; the sleeve is used to sleeve the wing frame that fixes the leading edge of the wing.

[0015] Furthermore, the dive-sweep device includes a second brushless motor, a third brushless motor and two pulling ropes; one end of the two pulling ropes is fixed to the wing frame of the corresponding wing, and then they are respectively wound and fixed on the shafts of the second brushless motor and the third brushless motor, and finally the other ends of the two pulling ropes are connected to the tail frame of the corresponding tail.

[0016] Furthermore, the wing frame and the tail frame use carbon fiber rods with a diameter less than 1 mm.

[0017] Furthermore, the wing variable camber control device comprises a first steering gear, a steering gear bracket, a spring, an elliptical top plate, a translation slider and a wing connecting member;

[0018] The first servo is fixed on the fuselage bracket through the servo bracket, and the elliptical top plate is connected to the first servo; one end of the spring is fixed to the front end of the fuselage bracket, and the other end is connected to the translation slider, the translation slider is hinged to the wing connecting piece, and the wing connecting piece is connected to the trailing edge part of the wing.

[0019] Furthermore, a slide groove matching the fuselage bracket is provided at the lower portion of the translation slider for free translation movement on the fuselage bracket.

[0020] Furthermore, the tail pitch control device comprises a second steering gear and a connecting plate, and the second steering gear is connected to the tail through the connecting plate;

[0021] The second steering gear rotates up and down, so that the connecting plate drives the tail wing to swing up and down, thereby changing the pitch attitude of the tail wing.

[0022] The present invention also provides a control method for a swift-like variable-morphology flapping-wing aircraft, which includes the following three working modes:

[0023] Gliding cruise mode: As the main flight mode, it drives the second brushless motor and the third brushless motor to open the traction rope and unfold the wings normally; drives the first servo to make the elliptical top plate support the translation slider, and the wing presents a flat shape; drives the second servo to make the tail plane parallel to the wing plane; controls the switch of the first brushless motor according to the gliding or flying instructions;

[0024] Dive mode: drive the first servo to make the elliptical top plate press against the translation slider, and the wing presents a flat shape; drive the second servo to make the tail plane parallel to the wing plane; drive the second and third brushless motors to rotate and wrap the traction rope, change the length of the traction rope to make the wing frame and the tail frame bend backwards, so as to achieve the swept effect; turn off the first brushless motor, and the dive mode does not perform flapping;

[0025] Climbing mode: drive the second brushless motor and the third brushless motor to open the pull rope and unfold the wings normally; drive the first servo to make the elliptical top plate deviate from the translation slider, and the trailing edge of the wing is pulled by the spring through the wing connector and the translation slider; the distance between the leading edge and the trailing edge of the wing decreases, the curvature increases, and the second servo is driven to increase the angle of attack of the tail wing; turn on the first brushless motor for flapping.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. Increase battery life: The flapping-wing aircraft can enter the gliding cruise mode and the dive mode without flapping, which can reduce the battery consumption rate and thus improve the battery life.

[0028] 2. Improve climbing efficiency: The climbing mode of the present invention changes the curvature of the wing, improves the energy utilization efficiency of the wing flapping, and at the same time increases the tail pitch angle to provide a moment of the nose pointing upward, so that the flapping-wing aircraft can climb faster and more efficiently, and the horizontal distance used for climbing is also shortened, making the flapping-wing aircraft more suitable for takeoff and lifting in a narrow space.

[0029] 3. Strong maneuverability: By sweeping back in a dive, the gravitational potential energy of the flapping-wing aircraft is converted into kinetic energy, and the altitude of the flapping-wing aircraft is reduced, which enhances the maneuverability of the flapping-wing aircraft and allows it to avoid searches at high altitudes. At the same time, sweeping back reduces resistance and ensures the conversion rate of gravitational potential energy to kinetic energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of a swift-like variable-shape flapping-wing aircraft of the present invention;

[0031] Figure 2 It is a schematic diagram of the structure of the flapping-wing drive device in the present invention;

[0032] Figure 3 It is a schematic diagram of the structure of the dive-sweep device in the present invention;

[0033] Figure 4 It is a schematic structural diagram of the wing variable camber control device in the present invention;

[0034] Figure 5 It is a structural schematic diagram of the tail pitch control device in the present invention;

[0035] Figure 6 It is a structural schematic diagram of three working modes of the flapping-wing aircraft in the present invention.

[0036] In the figure: 100-flapping wing drive device; 101-connecting rod; 102-first brushless motor; 103-fuselage bracket; 104-crank connector; 105-sleeve; 106-reduction gear set; 200-dive and sweep device; 201-second brushless motor; 202-third brushless motor; 203-pulling rope; 300-wing curvature control device; 301-first servo; 302-servo bracket; 303-spring; 304-elliptical top plate; 305-translational slider; 306-wing connector; 400-tail pitch control device; 401-second servo; 402-connecting plate; 500-wing; 510-wing frame; 600-tail; 610-tail frame; 700-housing. DETAILED DESCRIPTION

[0037] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention.

[0038] like Figure 1 As shown, a swift-like variable-shape flapping-wing aircraft comprises a fuselage bracket 103 and wings 500 and a tail 600 mounted on the fuselage bracket 103. The fuselage bracket 103 is equipped with a flapping-wing driving device 100, a dive-sweep device 200, a wing variable-camber control device 300, and a tail pitch control device 400. The flapping-wing driving device 100 generates a flapping motion, thereby realizing the flight of the aircraft.

[0039] like Figure 2As shown, the flapping-wing drive device 100 in this embodiment uses a conventional flapping-wing drive mechanism, including a first brushless motor 102, a reduction gear set 106, a crank connector 104, a connecting rod 101 and a sleeve 105. The first brushless motor 102 and the reduction gear set 106 are both fixed to the fuselage bracket 103; the output end of the first brushless motor 102 is connected to the driving gear of the reduction gear set 106, and the driven gear of the reduction gear set 106 is connected to the crank connectors 104 arranged on both sides of the fuselage bracket 103, and each crank connector 104 is hinged to the sleeve 105 through the connecting rod 101; the sleeve 105 is used to sleeve the wing frame of the leading edge of the fixed wing 500.

[0040] In the embodiment of the present invention, the above-mentioned flapping wing drive device 100 can be fixed with screws. In order to reduce weight, carbon fiber tubes can also be used instead of screws, and bonding is adopted to ensure a certain bonding strength, so that the device can operate normally.

[0041] like Figure 3 As shown, the dive-sweep device 200 includes a second brushless motor 201, a third brushless motor 202 and a pulling rope 203, wherein there are two pulling ropes 203, which are cross-mounted. In the embodiment of the present invention, the pulling rope 203 can be fixed to the wing frame 510 and the tail frame 610 by glue, and the pulling rope 203 is respectively wound around the shafts of the second brushless motor 201 and the third brushless motor 202, and can also be fixed by glue to ensure that there is no relative slip between the pulling rope 203 and the shafts of the second brushless motor 201 and the third brushless motor 202.

[0042] When the device is in operation, by driving the second brushless motor 201 and the third brushless motor 202 to rotate, the number of turns of the pulling rope 203 wrapped around the shafts of the second brushless motor 201 and the third brushless motor 202 increases, and the length of the unwound pulling rope 203 decreases, pulling the wing frame 510 and the tail frame 610, so that the wing frame 510 and the tail frame 610 bend backwards, achieving a swept effect.

[0043] In this embodiment, the wing frame 510 and the tail frame 610 use carbon fiber rods with a diameter less than 1 mm, which can produce large deflection bending deformation by applying a small force. The same effect can be achieved by using similar materials in other application scenarios.

[0044] like Figure 4As shown, the wing camber control device 300 includes a first servo 301, a servo bracket 302, a spring 303, an elliptical top plate 304, a translation slider 305, and a wing connector 306. The first servo 301 is fixed to the fuselage bracket 103 through the servo bracket 302, the elliptical top plate 304 is connected to the first servo 301, the spring 303 is connected to the translation slider 305, the translation slider 305 is hingedly connected to the wing connector 306, and the wing connector 306 is connected to the wing 500.

[0045] A slide groove is arranged at the bottom of the translation slider 305, so that the translation slider 305 can freely translate on the fuselage bracket 103, and the translation slider 305 is connected to the wing 500 through the wing connector 306, so the translation of the translation slider 305 is the translation of the trailing edge of the wing 500. Initially, the elliptical top plate 304 supports the translation slider 305, the spring 303 connected to the translation slider 305 is in a pre-stretched state, and the wing 500 is a plane; the first steering gear 301 controls the rotation of the elliptical top plate 304, so that the elliptical top plate 304 deviates from the translation slider 305, and the translation slider 305 is pulled back by the spring 303, that is, the trailing edge of the wing 500 moves forward, and the wing 500 has a certain curvature at this time. Since a small steering gear is used, the stiffness coefficient of the spring 303 should be selected to be smaller.

[0046] like Figure 5 As shown, the tail pitch control device 400 is composed of a second steering gear 401 and a connecting plate 402. The second steering gear 401 is connected to the tail 600 through the connecting plate 402.

[0047] When the tail pitch control device 400 is in effect, it drives the second steering gear 401 to rotate up and down, and drives the tail 600 to swing up and down through the connecting plate 402, so as to change the pitch attitude of the tail 600.

[0048] Except for the wing 500 and the tail 600, the rest of the exterior is covered by the outer shell 700, such as Figure 6 As shown, the control process of the above-mentioned swift-like variable-morphology flapping-wing aircraft includes the following three working modes:

[0049] (a) Gliding cruise mode: drive the second brushless motor 201 and the third brushless motor 202 to open the traction rope 203, the wing 500 is normally unfolded, drive the first servo 301 to make the elliptical top plate 304 support the translation slider 305, the wing 500 presents a plane shape, and drive the second servo 401 to make the tail 600 plane parallel to the wing plane. As the most important flight mode, the switch of the first brushless motor 102 is controlled according to the gliding or flying instructions, and non-flapping gliding can be performed to reduce energy consumption, and basic cruise flapping can also be performed.

[0050] (b) Dive mode: Drive the first servo 301 to make the elliptical top plate 304 bear against the translation slider 305, and the wing 500 presents a plane shape, and drive the second servo 401 to make the tail 600 plane parallel to the wing plane. By driving the second brushless motor 201 and the third brushless motor 202 to rotate and wrap the traction rope 203, the length of the traction rope 203 is reduced so that the wing frame 510 and the tail frame 610 are bent backwards, achieving a swept effect. Turn off the first brushless motor 102, and the dive mode does not flap. By sweeping back and diving, the altitude of the flapping-wing aircraft can be quickly changed to avoid attacks, and the gravitational potential energy can be converted into kinetic energy, thereby increasing the speed of the flapping-wing aircraft and enhancing its maneuverability.

[0051] (c) Climbing mode: Drive the second brushless motor 201 and the third brushless motor 202 to open the traction rope 203 and unfold the wing 500 normally. Drive the first servo 301 to rotate the elliptical top plate 304 away from the translation slider 305. The trailing edge of the wing 500 is pulled by the spring 303 through the translation slider 305. The distance between the leading edge and the trailing edge of the wing 500 is reduced, and the curvature is increased. Drive the second servo 401 to increase the angle of attack of the tail 600. Turn on the first brushless motor 102 to flap. By changing the angle of attack of the tail wing, a torque is provided to push the nose upward, the curvature of the wing is increased, and the climbing efficiency is comprehensively improved.

[0052] The flapping-wing aircraft and the control method thereof of the present invention can freely switch between the three working modes of gliding cruise, diving and climbing. The climbing mode improves the efficiency of climbing flight, and the diving mode reduces energy consumption and can fully improve the maneuverability of the flapping-wing aircraft. The flapping-wing aircraft completes the switching of the above three working modes through a simple mechanical structure, and improves the overall flight performance of the flapping-wing aircraft without increasing too much weight of the whole aircraft, ensuring that the flapping-wing aircraft can work for a longer time, adapt to more complex environments, and expand the working purpose of the flapping-wing aircraft.

[0053] The embodiments described above provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements and equivalent substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A swift-like variable-shape flapping-wing aircraft, characterized in that: It comprises a fuselage support (103) and a wing (500) and a tail wing (600) mounted on the fuselage support (103); The fuselage bracket (103) is also equipped with a flapping wing driving device (100) that matches the wing (500) and the tail wing (600), a dive and sweep device (200), a wing camber control device (300) and a tail wing pitch control device (400); The flapping-wing driving device (100) is used to drive the wing (500) to complete flapping motion; the dive-sweep device (200) is used to control the sweep effect of the wing (500) and the tail wing (600); the wing camber control device (300) is used to change the camber of the wing (500) by controlling the position of the trailing edge of the wing (500); and the tail wing pitch control device (400) is used to control the pitch of the tail wing (600); The wing camber control device (300) comprises a first steering gear (301), a steering gear bracket (302), a spring (303), an elliptical top plate (304), a translation slider (305) and a wing connecting piece (306); the first steering gear (301) is fixed to the fuselage bracket (103) through the steering gear bracket (302), and the elliptical top plate (304) is connected to the first steering gear (301); one end of the spring (303) is fixed to the front end of the fuselage bracket (103), and the other end is connected to the translation slider (305); the translation slider (305) is hingedly connected to the wing connecting piece (306), and the wing connecting piece (306) is connected to the trailing edge of the wing (500); the lower part of the translation slider (305) is provided with a slide groove matching the fuselage bracket (103) for free translation movement on the fuselage bracket (103).

2. The swift-like variable-shape flapping-wing aircraft according to claim 1, characterized in that: The flapping-wing driving device (100) comprises a first brushless motor (102), a reduction gear set (106), a crank connector (104), a connecting rod (101) and a sleeve (105); The first brushless motor (102) and the reduction gear set (106) are both fixed on the fuselage bracket (103); the output end of the first brushless motor (102) is connected to the driving gear of the reduction gear set (106); the driven gear of the reduction gear set (106) is connected to crank connectors (104) arranged on both sides of the fuselage bracket (103); each crank connector (104) is hinged to a sleeve (105) through a connecting rod (101); the sleeve (105) is used to sleeve a wing frame (510) that fixes the leading edge of the wing (500).

3. The swift-like variable-shape flapping-wing aircraft according to claim 1, characterized in that: The dive-sweep device (200) comprises a second brushless motor (201), a third brushless motor (202) and two pulling ropes (203); one end of the two pulling ropes (203) is fixed to the wing frame (510) of the corresponding wing (500), and then they are respectively wound and fixed on the shafts of the second brushless motor (201) and the third brushless motor (202), and finally the other ends of the two pulling ropes (203) are connected to the tail frame (610) of the corresponding tail (600).

4. The swift-like variable-shape flapping-wing aircraft according to claim 3, characterized in that: The wing frame (510) and the tail frame (610) are made of carbon fiber rods with a diameter less than 1 mm.

5. The swift-like variable-shape flapping-wing aircraft according to claim 1, characterized in that: The tail pitch control device (400) comprises a second steering gear (401) and a connecting plate (402), wherein the second steering gear (401) is connected to the tail (600) via the connecting plate (402); The second steering engine (401) rotates up and down, causing the connecting plate (402) to drive the tail wing (600) to swing up and down, thereby achieving a change in the pitch attitude of the tail wing (600).

6. The control method of the swift-like variable-shape flapping-wing aircraft according to any one of claims 1 to 5, characterized in that: There are three working modes: Gliding cruise mode: driving the second brushless motor (201) and the third brushless motor (202) so that the pulling rope (203) is opened and the wing (500) is normally unfolded; driving the first steering engine (301) so that the elliptical top plate (304) is supported against the translation slider (305) so that the wing (500) presents a plane shape; driving the second steering engine (401) so that the plane of the tail wing (600) is parallel to the plane of the wing; controlling the switch of the first brushless motor (102) according to the glide or flight instruction; Dive mode: drive the first servo (301) to make the elliptical top plate (304) press against the translation slider (305), so that the wing (500) presents a plane shape; drive the second servo (401) to make the tail wing (600) plane parallel to the wing plane; drive the second brushless motor (201) and the third brushless motor (202) to rotate and wind the traction rope (203), change the length of the traction rope (203) so that the wing frame (510) and the tail wing frame (610) bend backwards, so as to achieve a swept effect; turn off the first brushless motor (102), and the dive mode does not perform flapping; Climbing mode: driving the second brushless motor (201) and the third brushless motor (202) so that the pulling rope (203) is opened and the wing (500) is normally unfolded; driving the first steering gear (301) so that the elliptical top plate (304) deviates from the translation slider (305), and the trailing edge of the wing (500) is pulled by the spring (303) through the wing connecting member (306) and the translation slider (305); the distance between the leading edge and the trailing edge of the wing (500) is reduced, and the curvature is increased, and driving the second steering gear (401) so that the angle of attack of the tail wing (600) is increased; turning on the first brushless motor (102) to perform flapping.

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