Foldable wing aircraft based on wire and spring drive and flapping wing folding method

Abstract

The invention discloses a foldable wing aircraft driven by wires and springs and a flapping wing folding method, comprising a frame, a wing body, an active wing folding wire driving mechanism, an active wing unfolding spring driving mechanism and a driving control module; the active wing folding wire driving mechanism comprises a traction wire A, a traction wire B, a micro DC reduction motor and a bobbin; the passive wing unfolding spring driving mechanism comprises a torsion spring, a buckle P and a buckle N; the active wing unfolding spring driving mechanism comprises a traction wire C and a traction wire D; the driving control module comprises a power supply module, a single-chip control module and a motor driving module; the bionic foldable wing aircraft design based on wire and spring driving of the invention solves the problems of limited volume in transportation in narrow space, slow wing unfolding and retraction speed and complex structure of traditional flapping wing mechanisms, realizes rapid retraction and unfolding of the wings of flapping wing robots, and is of great significance to improving the flexibility of flapping wing robots and the research on aerodynamic characteristics of birds and insects.

Description

Technical Field

[0001] The invention relates to the fields of mechanics, bionics and origami technology, and in particular to a line- and spring-driven foldable-wing aircraft and a flapping-wing folding method. Background Art

[0002] Bionic aircraft have the characteristics of small size, light weight, low noise, good concealment, etc. They can realize some complex flight actions that are difficult for traditional aircraft to complete, such as vertical take-off and landing, hovering in the air, inverted flight, side flight, etc. They are suitable for various complex environments and tasks, and are widely used in education, scientific research, entertainment, military reconnaissance and other fields. However, since bionic robots mostly use flapping wing flight, the wingspan requirements are higher. At the same time, the larger the wings, the more space is required during transportation and storage, which also increases the risk of damage. This shortcoming restricts the practicality of bionic aircraft.

[0003] From the perspective of bionics, flapping-wing robots use periodic flapping to achieve flight modes such as cruising, vertical flight, and hovering flight. Compared with traditional fixed-wing and rotary-wing robots, they have more excellent maneuverability and efficiency, and are more concealed. They are widely used in military industry, rescue, and surveying. For all aircraft, wings are a very critical component. However, in order to obtain sufficient lift, the wings of flapping-wing robots are generally large, which makes flapping-wing robots often take up a large space during transportation and storage, greatly reducing the effective utilization of space. In addition, large wings are often more easily damaged and require more delicate protection. Obviously, these shortcomings limit the practical application value and cost-effectiveness of flapping-wing robots. If the wings of flapping-wing robots can be foldable, it will greatly improve their practicality and safety.

[0004] The wings of ladybugs in nature are foldable, which not only improves the utilization of space, but also ensures that the wings can be well protected under the wing sheath. By studying the images of ladybugs flying, it can be found that when the wings of ladybugs hit obstacles during flight, the foldable wings can absorb the impact of the collision by folding and convert the impact into elastic force. After the collision, the elastic force is immediately released, allowing the wings to quickly unfold again, thus ensuring the stability of its flight to a certain extent.

[0005] Origami is an art form that can be seen everywhere in our daily lives. Through a certain folding sequence, a piece of paper can be greatly reduced. Moreover, some origami artworks only need to exert certain forces at a few specific creases to quickly unfold the paper without damaging it.

[0006] Therefore, the applicant uses origami technology to design a foldable wing type and applies it to bionic aircraft, which will greatly reduce its transportation cost, save many protective measures, and greatly increase its cost-effectiveness. Summary of the invention

[0007] In order to overcome the problem that the robot cannot pass through a narrow space due to its limited size, and to be able to quickly unfold when reaching a designated location to maximize its application value, the present invention proposes a foldable wing aircraft driven by wires and springs and a flapping wing folding method to overcome the shortcomings of existing flapping-wing micro-aircraft, such as large wing size, low space utilization, inflexible telescopic structure, poor concealment, and easy exposure of the target, and provide ideas for the optimization and innovation of future folding methods and small drive structures.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] A wire-and-spring driven foldable wing aircraft, characterized in that it consists of a frame, a wing body, an active wing folding wire drive mechanism, a passive wing unfolding spring drive mechanism and a drive control module.

[0010] The frame includes a main frame and a sub-frame. The main frame supports the entire aircraft, and the extension and retraction of the wings are completed on the main frame. There are two sub-frames, and the left and right parts are symmetrical, which fix the active folding drive mechanism and the drive control module of the wing.

[0011] The wing body is folded from paper and has 21 faces; the concave lines at the interface between the faces are valley lines, and the convex lines are mountain lines. There are 17 valley lines and 15 mountain lines at the interface between the faces.

[0012] At the same time, the wing active folding line driving mechanism and the wing passive unfolding spring driving mechanism are installed on the wing body;

[0013] The active folding wire driving mechanism of the wing comprises two active folding wire driving traction wires, two DC reduction motors and two bobbins; the active folding wire driving traction wire continuously passes through five folding surfaces, the bobbin is interlocked with the rotor at the output end of the motor, the traction wire is passed through the hole on the bobbin surface and then passed out, the wire is pulled out in the opposite direction of the insertion direction, and the part away from the wire end is wound along the outer diameter to fix the traction wire and the bobbin; when the motor rotates, the bobbin can be driven to rotate, so that the traction wire is wound around the bobbin, providing driving force for wing folding;

[0014] The wing passive deployment spring drive mechanism includes 3 torsion springs and 12 buckles, 6 of which have a convex shape and a U-shaped groove, and the rest have a concave shape matching the above buckles. The 6 buckles are placed on the front side of the wing, and the rest are placed on the back side. The two buckles are matched and fixed by the complementary structure between the two buckles, and the end of the torsion spring is bent and clamped in the U-shaped groove to fix it;

[0015] The wing active deployment line driving mechanism includes two active deployment line driving traction lines, and the active deployment line driving traction lines continuously pass through the four folding surfaces, then pass through the connecting surface and then pass out from the outer side surface;

[0016] The drive control module is used to control the forward and reverse rotation and speed of the DC reduction motor, thereby realizing active folding and unfolding of the wing.

[0017] As a further improvement of the aircraft of the present invention, the wing body is made of kraft paper.

[0018] As a further improvement of the aircraft of the present invention, the drive control module is composed of an STM32F407VG board, an independent 12V voltage source, an ASM1117 step-down module and an L298N drive module.

[0019] As a further improvement of the aircraft of the present invention, a metal gasket is installed on the hole through which the traction line passes.

[0020] The present invention provides a wing folding method for an aircraft, which is characterized in that the specific method is as follows: a driving control module controls a DC reduction motor and supplies power to the motor through a power supply;

[0021] By programming to output a PWM wave of appropriate size, connecting the ENA pin, the motor speed is controlled; at the same time, the two pins are controlled to output high and low levels to the IN1 and IN2 pins respectively to control the direction of the motor, and the key switch peripherals are set. When the switch is pressed once, the motor rotates in the forward direction, driving the spool to rotate, and the traction line is wound around the spool. The traction and folding process is carried out. After n positive rotations, the folding is complete and the motor stops. When the switch is pressed again, the motor reverses and the traction line spreads out from the spool. Under the action of the torsion spring, the wings gradually unfold and are completely unfolded after n reverse rotations, and the motor stops.

[0022] Compared with the prior art, the technical solution of the present invention will have the following beneficial effects:

[0023] (1) The bionic foldable wing aircraft designed in the present invention uses origami technology to achieve the extension and contraction of bionic wings. Due to the memory of the creases, it is only necessary to determine the shape of the extension and contraction when manufacturing the aircraft. After completion, each folding process will autonomously have exactly the same shape, which is inspiring for saving machinery costs in mass production and practical applications.

[0024] (2) In the aircraft designed by the present invention, the process of wing retraction is achieved by using a motor-driven traction line. The folds divide the wings into many different surfaces, and the traction lines are inserted into and out of the key depressions. The traction lines are driven by motors, and the fit between the different surfaces of the origami can be controlled artificially by applying tension to the lines. This has stability and operability, and proposes a new idea for bionic structures.

[0025] (3) In the aircraft designed by the present invention, the process of wing extension uses the elastic force of the torsion spring to achieve passive unfolding. The torsion spring with a free angle of 180° can stretch the paper in a natural state to simulate the unfolding of the wings. As long as the motor drives the traction line, the spring can be compressed without affecting the folding process. The elastic force of the spring makes the unfolding speed of the wings reach a very high level, which is in line with the biological characteristics of nature. This feature also makes the design have great potential in the application field.

[0026] (4) The present invention proposes an actively driven flapping wing unfolding method, which utilizes a traction line to unfold the folded structure. The line is threaded at the crease protrusion, and the contraction of the traction line can be controlled by providing tension to the line, thereby exerting force on the paper to unfold it. The two complementary threading methods are respectively for the folding and unfolding processes, so that the entire folding and unfolding process can be controlled by a simple line, providing another new idea and method for line traction control technology and automatic paper folding technology.

[0027] (5) The bionic foldable wing aircraft makes full use of origami technology, wire drive, and spring extension technology, which greatly improves the space utilization rate. It has considerable application prospects for space-constrained processes such as gastroenterology, micro-robots, and launching space probes. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is an overall schematic diagram of the foldable wing aircraft of the present invention;

[0029] Figure 2 is a schematic diagram of the fully unfolded foldable wing aircraft of the present invention;

[0030] Figure 3 It is a schematic diagram of the spool designed by the present invention;

[0031] Figure 4 It is a schematic diagram of the buckle P designed in the present invention;

[0032] Figure 5 This is a schematic diagram of the buckle N designed in the present invention;

[0033] Figure 6 It is a schematic diagram of the torsion spring and the buckle designed in the present invention;

[0034] Figure 7 It is a schematic diagram of the design drive control flow of the present invention;

[0035] Figure 8 It is a schematic diagram of the driving control simulation designed by the present invention;

[0036] Fig. 9 It is a schematic diagram of the bionic wing origami structure model of the present invention;

[0037] Fig.10 It is a front threading diagram of the bionic wing structure of the present invention;

[0038] Fig.11 It is a schematic diagram of the structure of the S1 state when the linear drive wing of the present invention is folded 10%;

[0039] Fig.12 It is a schematic diagram of the structure of the S2 state when the line-driven wing of the present invention is folded 30%;

[0040] Fig.13 It is a schematic diagram of the structure of the S3 state when the linear drive wing of the present invention is folded 50%;

[0041] Fig.14 It is a schematic diagram of the structure of the S4 state when the line-driven wing of the present invention is folded 70%;

[0042] Fig.15 It is a schematic diagram of the structure of the S5 state when the line-driven wing of the present invention is folded 90%;

[0043] Fig.16 It is a front threading diagram of the active deployment wing structure of the present invention;

[0044] Fig.17 This is a schematic diagram of the structure of the S6 state when the right wing of the present invention is actively unfolded and the wing unfolding process is 20%;

[0045] Fig.18 This is a schematic diagram of the structure of the S7 state when the right wing of the present invention is actively unfolded and the wing unfolding process is 50%;

[0046] Fig.19 It is a schematic diagram of the structure of the S8 state when the right wing of the present invention is actively unfolded and the wing unfolding process is 90%. Implementation

[0047] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0048] Reference Figure 1A bionic foldable wing aircraft based on wire and spring drive is composed of a frame I, a wing body II, a wing active contraction wire drive mechanism III, a wing active expansion spring drive mechanism IV, and a drive control module V. The frame I is used to fix the above mechanisms, devices and corresponding modules. The wing body II is the main bionic foldable wing structure. The wing active contraction wire drive mechanism III is controlled by the drive control module, and the traction wire A, traction wire B, metal gasket, DC reduction motor and bobbin cooperate with each other to provide tension to achieve the folding of the key parts of the wing, which plays an auxiliary role in the memory of origami. The wing passive expansion spring drive mechanism IV is composed of a buckle and a torsion spring, which is used to realize the expansion of the wings. The drive control module V includes an STM32F407VG board, an independent 12V voltage source, an ASM1117 step-down module and an L298N drive module to provide rope tension for the wing active contraction wire drive mechanism.

[0049] Reference Figure 1 , Figure 2 The frame I includes a main frame I-1, a sub-frame I-2-1, and a sub-frame I-2-2. The main frame I-1 supports the entire aircraft, and the extension and retraction of the wings are completed on the main frame. The sub-frames I-2-1 and I-2-2 are symmetrical on the left and right, and are fixed with DC reduction motors and other wing active folding drive mechanisms and drive control module V.

[0050] refer to Fig. 9 The wing is made of 150g A4 kraft paper, and its folding mechanism is as follows: (1) Drive surface 1 to fold along valley line p toward surface 2, and surface 3 to fold along mountain line q toward surface 2. Due to the memory of paper, in this process, surface 4 is driven to fold along valley line a1 toward surface 1, surface 5 is driven to fold along mountain line d1 toward surface 4, and along valley line b1 toward surface 2, surface 13 is driven to fold along valley line a2 toward surface 1, surface 14 is driven to fold along mountain line d2 toward surface 13, and along valley line b2 toward surface 2; (2) Drive surface 7 to fold along valley line g1 toward surface 5, and surface 16 to fold along valley line g2 toward surface 14 Folding, due to the memory of the paper, in this process, surface 8 is driven to fold along the mountain line h1 to surface 7, surface 10 is driven to fold along the mountain line i1 to surface 7, surface 17 is driven to fold along the mountain line h2 to surface 16, and surface 19 is driven to fold along the mountain line i2 to surface 16; (3) surface 11 is driven to fold along the valley line m1 to surface 10, and surface 20 is driven to fold along the valley line m2 to surface 19. Due to the memory of the paper, in this process, surface 9 is driven to fold along the mountain line l1 to surface 10, surface 12 is driven to fold along the mountain line o1 to surface 11, surface 18 is driven to fold along the mountain line l2 to surface 19, and surface 21 is driven to fold along the mountain line o2 to surface 20. At this point, the wing body is folded.

[0051] Reference Figure 2 , Figure 3 , Fig.10 , Fig.11 , Fig.12 , Fig.13 , Fig.14, Fig.15 The passive contraction line drive mechanism III of the wing includes a DC reduction motor, a bobbin, a metal gasket, and a traction line. The DC reduction motor has a rotation speed of 40r / min, a rated torque of 6kg / cm, and can provide a traction force of 50N. The contraction drive mechanism of the left wing of the wing is as follows: the bobbin 3' is interlocked with the output end of the DC reduction motor 1', and the traction line A is inserted from the bottom of the surface 1, and passes through the top of the surface 2, the bottom of the surface 2, the top of the surface 5, the bottom of the surface 5, the top of the surface 7, the bottom of the surface 10, and the top of the surface 11, and then passes through the bottom of the surface 11, the top of the surface 10, the bottom of the surface 7, the top of the surface 5, the bottom of the surface 5, the top of the surface 2, and the bottom of the surface 2, and finally passes out from the bottom of the surface 1. A metal gasket is installed on each penetration hole to reduce the friction between the traction line and the hole, while maintaining the integrity of the hole. The two ends of the traction line A are combined, and they are inserted from the bobbin hole 3'-1 together, and pass out from the hole 3'-2, and are wound back along the outer diameter of the shaft and tied to fix. When the drive control module makes the motor 1' rotate, the traction line A is pulled through the spool 3'. First, the traction line A drives the surface 1 to fold toward the surface 2 along the valley line p, and the surface 3 to fold toward the surface 2 along the mountain line q, and then drives the surface 7 to fold toward the surface 5 along the valley line g1, and finally drives the surface 11 to fold toward the surface 10 along the valley line m1, so that the left wing is completely retracted. The principle of the right wing retraction line drive mechanism is the same as that of the left wing. After the wing is completely folded, the motor stops rotating, pulls the traction lines A and B, and presses the torsion spring to keep the wing in a retracted state. Fig.11 , 12 13, 14, and 15 are the line and surface position distributions of the present invention under the action of traction lines A and B in five states S1, S2, S3, S4, and S5 where the wing folding rates are 10%, 30%, 50%, 70%, and 90%, respectively.

[0052] Reference Figure 2 , Figure 4 , Figure 5 , Fig.10The wing passive deployment spring drive mechanism IV includes a torsion spring 5`-1, a torsion spring 5`-2, a torsion spring 5`-3, a buckle P-1-1, a buckle N-1-2, a buckle P-1-3, a buckle N-1-4, a buckle P-2-1, a buckle N-2-2, a buckle P-2-3, a buckle N-2-4, a buckle P-3-1, a buckle N-3-2, a buckle P-3-3, and a buckle N-3-4, wherein the buckle P-1-1, the buckle P-1-3, the buckle P-2-1, the buckle P-2-3, the buckle P-3-1, and the buckle P-3-3 have a convex shape and a U-shaped groove, and the rest have a concave shape matching the above-mentioned buckles. Buckle P-1-1, buckle P-1-3, buckle P-2-1, buckle P-2-3, buckle P-3-1, buckle P-3-3 are placed on the front of the wing, and the rest of the buckles are placed on the back. The end of the torsion spring is bent and stuck in the U-shaped groove. When the power is turned on, the motor outputs, pulls the traction line, the wings fold and compress the spring, the motor reverses to release the traction line on the spool, the torsion spring returns to its original state, generates elastic force and automatically opens, and cooperates with the buckle to drive the wings to unfold quickly.

[0053] Reference Fig.16 , the wing active deployment drive mechanism includes a traction line C and a traction line D. The traction line C passes through the bottom of surface 17, passes through the top of surface 17, the top of surface 16, the bottom of surface 16, the top of surface 19, the bottom of surface 20, and finally passes through the top of surface 20. The traction line D passes through the bottom of surface 8, passes through the top of surface 8, the top of surface 7, the bottom of surface 7, the top of surface 10, the bottom of surface 11, and finally passes through the top of surface 11. After the motor is reversed, a pulling force is applied to both ends of the traction line C. First, surface 20 is separated from surface 19, surface 17 and surface 18, then surface 17 is separated from surface 16, surface 18 is separated from surface 19, and finally surface 15 rotates downward and surface 17 rotates upward to complete the left wing deployment process. A pulling force is applied to both ends of the traction line D. First, surface 11 is separated from surface 10, surface 8 and surface 9, then surface 7 is separated from surface 8, surface 9 is separated from surface 10, and finally surface 6 rotates downward and surface 8 rotates upward to complete the right wing deployment process. Attachment Fig.17 , 18 19 are the line and surface position distributions of the right wing under the action of the traction line D when the deployment process is 10%, 50%, and 90% in three states S6, S7, and S8 respectively.

[0054] Reference Figure 7 , Figure 8The control principle of the drive control module V is as follows: use the stm32f407vg board, independent 12v voltage source, asm1117 step-down module, and l298n drive module to control the DC reduction motor. The independent 12v power supply supplies power to the l298n; the l298n outputs a 5v voltage that is stepped down to 3.3v by asm1117 to power the stm32f407vg board, and the motor1 output interface of the l298n supplies power to the motor; through programming, the stm32f407vg outputs a suitable size PWM wave, which is connected to the ENA pin of the l298n to control the motor speed; at the same time, the two pins are controlled to output high and low levels to the IN1 and IN2 pins of the l298n respectively to control the direction of the motor (1 represents a high level, and 0 represents a low level, then 1 and 0 are forward, and 0 and 1 are reverse). Set the key switch peripherals, press the switch once, the motor will stop after n turns forward, and press the switch again, the motor will stop after n turns reverse.

[0055] The above description is only a preferred embodiment of the present invention and does not constitute any other form of limitation to the present invention. Any modification or equivalent change made based on the technical essence of the present invention still falls within the scope of protection required by the present invention.

Claims

1. A wire and spring driven foldable wing aircraft, characterized in that: It consists of a frame, a wing body, a wing active folding line drive mechanism, a wing passive unfolding spring drive mechanism and a drive control module; The frame includes a main frame and a sub-frame. The main frame supports the entire aircraft, and the extension and retraction of the wings are completed on the main frame. There are two sub-frames, and the left and right parts are symmetrical, which fix the active folding drive mechanism and the drive control module of the wing. The wing body is folded from paper and has 21 faces; the concave lines at the interface between the faces are valley lines, and the convex lines are mountain lines. There are 17 valley lines and 15 mountain lines at the interface between the faces. At the same time, the wing active folding line driving mechanism and the wing passive unfolding spring driving mechanism are installed on the wing body; The active folding wire driving mechanism of the wing comprises two active folding wire driving traction wires, two DC reduction motors and two bobbins; the active folding wire driving traction wire continuously passes through five folding surfaces, the bobbin is interlocked with the rotor at the output end of the motor, the traction wire is passed through the hole on the bobbin surface and then passed out, the wire is pulled out in the opposite direction of the insertion direction, and the part away from the wire end is wound along the outer diameter to fix the traction wire and the bobbin; when the motor rotates, the bobbin can be driven to rotate, so that the traction wire is wound around the bobbin, providing driving force for wing folding; Pull line A enters from the bottom of surface 1, passes through the top of surface 2, the bottom of surface 2, the top of surface 5, the bottom of surface 5, the top of surface 7, the bottom of surface 10, the top of surface 11, the bottom of surface 11, the top of surface 10, the bottom of surface 7, the top of surface 5, the bottom of surface 5, the top of surface 2, the bottom of surface 2, and finally passes out from the bottom of surface 1; The wing passive deployment spring drive mechanism includes 3 torsion springs and 12 buckles, 6 of which have a convex shape and a U-shaped groove, and the rest have a concave shape matching the above buckles. The 6 buckles are placed on the front side of the wing, and the rest are placed on the back side. The two buckles are matched and fixed by the complementary structure between the two buckles, and the end of the torsion spring is bent and clamped in the U-shaped groove to fix it; The wing active deployment line driving mechanism includes two active deployment line driving traction lines, and the active deployment line driving traction lines continuously pass through the four folding surfaces, then pass through the connecting surface and then pass out from the outer side surface; The wing active deployment drive mechanism includes a traction line C and a traction line D. The traction line C passes through the bottom of the surface 17, passes through the top of the surface 17, passes through the top of the surface 16, passes through the bottom of the surface 16, passes through the top of the surface 19, passes through the bottom of the surface 20, and finally passes through the top of the surface 20. The traction line D passes through the bottom of the surface 8, passes through the top of the surface 8, passes through the top of the surface 7, passes through the bottom of the surface 7, passes through the top of the surface 10, passes through the bottom of the surface 11, and finally passes through the top of the surface 11. The drive control module is used to control the forward and reverse rotation and speed of the DC reduction motor, thereby realizing active folding and unfolding of the wing.

2. The wire-and-spring driven foldable wing aircraft according to claim 1, characterized in that: The wing body is made of kraft paper.

3. The wire-and-spring driven foldable wing aircraft according to claim 1, characterized in that: The drive control module is composed of an STM32F407VG board, an independent 12V voltage source, an ASM1117 step-down module and an L298N drive module.

4. The wire-and-spring driven foldable wing aircraft according to claim 1, characterized in that: A metal gasket is installed on the hole through which the traction line passes.

5. A method for folding wings of an aircraft based on the wire and spring driven foldable wing aircraft according to any one of claims 1 to 4, characterized in that ,The specific method is as follows: the drive control module controls the DC reduction motor and supplies power to the motor through the power supply; By programming to output a PWM wave of appropriate size, connecting the ENA pin, the motor speed is controlled; at the same time, the two pins are controlled to output high and low levels to the IN1 and IN2 pins respectively to control the direction of the motor, and the key switch peripherals are set. When the switch is pressed once, the motor rotates in the forward direction, driving the spool to rotate, and the traction line is wound around the spool. The traction and folding process is carried out. After n positive rotations, the folding is complete and the motor stops. When the switch is pressed again, the motor reverses and the traction line spreads out from the spool. Under the action of the torsion spring, the wings gradually unfold and are completely unfolded after n reverse rotations, and the motor stops.

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