Modular bow and arrow unmanned aerial vehicle launcher using super elastic memory alloy wire

Abstract

The application discloses a modularized bow and arrow type fixed-wing unmanned aerial vehicle launching device using super-elastic memory alloy wires, which mainly comprises a slide, a bow and arrow integrated structure, memory alloy wires, a stretching structure, a launching structure, a buffer structure, an L-shaped structure, a guide rail structure and a Chinese character 'zhong' shaped structure.Combining the modularized bow and arrow type, by changing the stretching distance and the deformation amount of the super-elastic memory alloy wires, the energy density during ejection is changed by using the resistance self-sensing characteristics of the memory alloy, so that the launching performance of the fixed-wing unmanned aerial vehicle is controlled.After the device is installed, the stretching structure is moved along the guide rail to a preset position, the super-elastic memory alloy wires are released by using the launching structure, the fixed-wing unmanned aerial vehicle slides along the slide until the lower sliding block hits the buffer device, and the unmanned aerial vehicle is launched by the impact force.The application has advanced guiding significance and practical value for the application of the memory alloy wires and the fixed-wing unmanned aerial vehicle launching device.

Description

Technical Field

[0001] This invention belongs to the field of hyperelastic shape memory alloys and fixed-wing UAV launch, specifically relating to a method for combining traditional bows and arrows with hyperelastic shape memory alloy wires to meet the launch requirements of fixed-wing UAVs. Background Technology

[0002] After decades of development, fixed-wing drones have found increasingly wider applications. Generally, launching a fixed-wing drone requires a significant amount of propulsion. Currently, most fixed-wing drone catapults are electromagnetically driven, hydraulically driven, or pneumatically driven. Traditional fixed-wing drone catapults, to achieve sufficient propulsion and high-speed launch, need to be large in size and mass. While the existing propulsion methods for fixed-wing drones each have their advantages, they also have drawbacks. Because launching a fixed-wing drone requires a large amount of energy, this results in a bulky and large catapult device.

[0003] Hyperelastic shape memory alloy wires exhibit pseudoelasticity. Shape memory alloys possess excellent self-sensing properties because their resistance change rate is related to strain. This allows for the determination of the relationship between energy density and strain, ultimately enabling the acquisition of energy density and energy conversion efficiency simply by measuring the resistance value, without the need for other sensors. Shape memory alloy wires induce large stresses and strains, resulting in excellent energy storage characteristics. The stored energy is influenced by the wire diameter, length, and loading.

[0004] In this context, a modular bow-and-arrow design can be used to reduce the size of the drone catapult and simplify its carrying method. Currently, research on the application of shape memory alloys (MMEs) in fixed-wing drone catapults regarding their drive structure and relationships is still insufficient. Therefore, MMEs can be incorporated into modular bow-and-arrow type fixed-wing drone catapults. Utilizing the excellent energy storage properties of MMEs, a large elastic force can be achieved with very small strain, enabling high-speed launch. Furthermore, utilizing the excellent self-sensing properties of MMEs, launch performance indicators can be directly obtained by measuring resistance. Therefore, it is necessary to explore the specific structure and precise relationships of MME-based bow-and-arrow type fixed-wing drone catapults based on existing research to optimize fixed-wing drone catapult performance, simplify the catapult, and further broaden the application scenarios of MMEs, allowing them to play a valuable role in more fields. Summary of the Invention

[0005] To address existing launch performance issues, a superelastic shape memory alloy wire is mounted on the arrow, which is then launched using a trigger mechanism. Two parallel rails are fixed on a guide rail, using high-precision rails to limit the aircraft's gliding trajectory, achieving better launch results and a simpler launch method.

[0006] The above-mentioned objective of this invention is achieved through the following technical solution:

[0007] A modular bow and arrow device includes an overall bow and arrow structure, a fixed end structure, and a connecting assembly. The connecting assembly is implemented using a superelastic shape memory alloy wire. The fixed end structure includes hexagonal bolts, hexagonal nuts, and a special end segment. The overall bow and arrow structure includes a middle segment, a general segment, and a special end segment. The general segment is divided into three layers, with the upper and lower layers having conjugate contours. Two hexagonal nut holes are provided on the middle segment. The special end segment is formed by elongating and chamfering the general segment before creating the hexagonal nut holes.

[0008] A firing device based on a gun structure includes a trigger structure, a tensioning structure, and a pushing structure. The trigger structure includes a spring, a spring stop, an extension plate, a rotating structure, a pull lever, an upper and lower plate fixing structure, and upper and lower plates. The tensioning structure is connected to a slider, and the tensioning effect is achieved by the slider sliding on a track. The pushing structure includes a pushing plate.

[0009] An aircraft taxiing device includes a taxiway, a slider, and a guide rail structure.

[0010] The modular bow and arrow structure 2, modular slide 1, and modular guide rail 8 are connected in series by superelastic shape memory alloy wire 3. After series connection, the guide rail 8 passes through the U-shaped structure 10, connecting the bow and arrow structure 2 and the modular guide rail 6. The metal frame 9 of the buffer device is connected to the bow and arrow structure 2, and then the buffer rubber 6 is installed into the metal frame 9. The L-shaped fixing structure 7 is connected to the modular guide rail 8, and then the modular slide 1 is connected to the L-shaped fixing structure 7. The pushing structure 4 is connected to the slider 11 using threaded holes, and then the launching structure 5 is connected to the guide rail 8 using threads.

[0011] In the launching structure, spring F1 is mounted on rotating structure F5, and then rotating structure F5 and trigger F6 are mounted together on the lower plate. Finally, the upper and lower plates are connected by upper and lower plate fixing structures F3, F7 and F8.

[0012] The advantages of this invention are:

[0013] 1. Modular bows and arrows are easy to transport, carry, and place, which is a significant advantage over ordinary fixed-wing drone catapults. Compared with traditional electromagnetic, hydraulic, and pneumatic catapults, fixed-wing drone catapults based on superelastic shape memory alloy wires are lighter and more convenient.

[0014] 2. The modular bow and arrow can change the length of the bow and arrow by changing the number of segments, adjust the mechanical properties of the bow and arrow, and different lengths of the bow and arrow can achieve different launching effects. In addition, different installation positions of the bow and arrow can change the stretching degree of the super-elastic memory alloy wire, so the launching performance can also be adjusted by changing the installation position.

[0015] 3. The super-elastic memory alloy wire has good self-sensing characteristics and physical properties. Its mechanical relationship is stable and simple, and there is a relatively good linear relationship among the energy density, resistance change rate and strain physical quantity. Such a linear property makes it relatively easy to control physical quantities such as the launching speed when launching a fixed-wing unmanned aircraft. Without adding other sensors for measurement, the required physical quantities such as energy density can be obtained, and the effect of changing the energy density of the alloy wire can be achieved by changing the length and diameter of the super-elastic memory alloy wire.

[0016] 4. The bow and arrow are connected by the super-elastic memory alloy wire. The energy density of the memory alloy wire is higher than that of ordinary materials, and the energy storage performance is better than that of ordinary alloy wires. Therefore, the driving force after the memory alloy wire is released is very strong, and it can obtain greater energy than ordinary alloy wires.

[0017] 5. After the super-elastic memory alloy wire is released, it pushes the aircraft through the guide rail. The guide rail is combined with the slideway, and the accuracy of the guide rail is higher than that of the ordinary slideway. Therefore, the guiding performance during launching is good. A "middle" - shaped installation method is designed for the part where the bow and arrow are connected to the guide rail. The release method of the super-elastic memory alloy wire is novel, different from the traditional hand-held release method, and the degree of simplification is higher. Description of the Drawings

[0018] Figure 1 : Schematic diagram of the overall structure assembly

[0019] Figure 2 : Schematic diagram of the overall structure design

[0020] Figure 3 : Schematic diagram of the end assembly

[0021] Figure 4 : Schematic diagram of the guide rail structure

[0022] Figure 5 : Schematic diagram of the "middle" - shaped structure

[0023] Figure 6 : Schematic diagram of the stretching structure

[0024] Figure 7 : Schematic diagram of the launching structure

[0025] Figure 8 : Schematic diagram of the slideway structure

[0026] In the figure: 1 is a modular slideway, 2 is a modular bow and arrow, 3 is a super-elastic shape memory alloy wire, 4 is a stretching structure, 5 is a launching structure, 6 is a buffer structure, 7 is an "L"-shaped fixing structure, 8 is a modular guide rail, 9 is the metal outer frame of the buffer device, 10 is a "middle"-shaped fixing structure, 11 is a slider, 12 is a fixed-wing UAV model, B1 is a variable cross-section hole, B2 is a hexagonal nut groove, B3 is a gasket, C1 is the hole of the bolt rod, C2 is a hexagonal nut, C3 is a bolt, P1 is the top-layer structure of the end segment, P2 is the middle-layer structure of the end segment, P3 is the bottom-layer structure of the end segment, P4 is the conjugate contour on the top layer, G1 is the threaded hole on the slider, G3 is the counterbore on the guide rail, Z1 is a threaded hole, Z2 is a through hole, Z3 is a threaded hole, Z4 is a guide rail groove, L1 is a pushing piece, L2 is a through hole, L3 is a hook, L4 is a clamping groove, L5 is a threaded hole, F1 is a spring, F2 is a spring baffle, F4 is an extension plate, F5 is a rotating structure, F6 is a trigger wrench, F3, F7 and F8 are the upper and lower plate fixing structures, F9 is the upper plate, F10 is a through hole, S1 and S2 are slideway segments. Detailed implementation mode

[0027] The bow and arrow is decomposed into several segments with the same shape and size for design. Each segment includes three layers: upper, middle and lower. Conjugate contours are formed between adjacent segments, and they are assembled by flipping up and down and meshing with each other in sequence to form the shape of the bow and arrow.

[0028] Refer to the appendix Figure 1-3 , and models of 8 general segments of the bow and arrow, 2 end segments and 1 middle segment of the bow and arrow are established. Each segment includes three layers P1, P2 and P3 similar to the end segment, where the upper layer P1 and the lower layer P3 are meshed with each other through the structure P4. The middle layer P2 is provided with through holes to facilitate the penetration of the shape memory alloy wire, and two nut holes are reserved in the lower layer P3 of the middle segment. The segments are flipped up and down and assembled through the super-elastic shape memory alloy wire, and the overall structure is axisymmetric about the middle segment.

[0029] Refer to the appendix Figure 3 , the end segment is pre-set with nut holes B2 and variable cross-section holes B1 for the alloy wire, and two M3 nuts are embedded in the hole B2. Fixing structures identical to those on the other side are placed at the nut hole B2. The super-elastic shape memory alloy wire is penetrated from the outside of the right end segment, and after the segments are connected in series, it penetrates from the inside of the left end segment and then winds back to the right. The fixing method is that the shape memory alloy wire first penetrates out from the variable cross-section hole B1 on the side of the end segment, then penetrates out through the reserved hole C1 of the bolt, and after penetration, it is wound around the bolt rod C3 for several turns, and then the super-elastic shape memory alloy wire is clamped by two identical gaskets B3, and a nut C2 is tightened above to achieve the fixing function.

[0030] Refer to the appendix Figure 4 , 5, 8. Establish a modular guide rail model. The overall design of the guide rail is a modular structure, which is connected in series using super-elastic alloy wires similar to a bow and arrow. Referring to the slideway structure, a pair of structures similar to the conjugate profiles S1 and S2 are established to ensure the straightness of the guide rail. The guide rail is connected to the overall structure of the bow and arrow using a "middle" - shaped fixing structure. Among them, the "middle" - shaped structure is flipped, with a side hole Z4, allowing the guide rail to pass through the middle. Use Z3 to connect the nut hole reserved in the middle section of the bow and arrow to this structure. Three identical holes Z1 are connected to the lower end of the guide rail, thus realizing the connection between the guide rail and the bow and arrow structure.

[0031] Refer to the appendix Figure 4-7 , establish a model of the stretching structure of the bow and arrow. The stretching structure is fixed using bolts and installed on a slider structure that配合 with the above - mentioned guide rail. The two are connected using the threaded hole G3 set on the slider structure and the threaded hole L5 set on the stretching structure. Among them, the hole L2 is set to allow a screwdriver to smoothly enter the threaded hole L5 for installation. In the stretching structure, a pushing piece L1 needs to be established to push the aircraft to slide; a hook L3 is established so that it can be clamped by the rotating structure F5 in the launching device when stretched to a preset position; a slot L4 is established to install the super - elastic memory alloy wire into the slot for loading. In the stretching structure, the loading device uses an electromagnetic - iron loading device.

[0032] Refer to the appendix Figure 6 , 7 , establish a launching structure model. The launching structure includes a spring F1, a spring baffle F2, an extension plate F4, a rotating structure F5, a trigger wrench F6, upper and lower plate fixing structures F3, F7, and F8. Connect the above - mentioned guide rail model to the launching structure through the extension plate F4 and the preset holes on F4. F8 is connected to the hole F10 on the upper plate, and the upper and lower plate fixing structures F3 and F7 are the same. When the rotating structure F5 clamps the hook L3, press the trigger wrench F6, which will cause the rotating structure F5 to rotate around the fixing structure F3, thus releasing the stretching structure. After the rotating structure F5 rotates, it squeezes the spring F1, and the upper end of the spring is restricted by the spring baffle F2, so the rotating structure F5 will reset to its original state.

[0033] Refer to the appendix Figure 2 , 8A modular aircraft slide structure 1 is constructed. The slide itself is also designed modularly, similar to a bow and arrow, using superelastic shape memory alloy wires for interconnection. To ensure the slide remains as straight as possible after interconnection, a modular structural design is employed, creating a pair of conjugate profiles S1 and S2 to guarantee its straightness. Two "L"-shaped fixing structures 7 are constructed, connecting the slide to the guide rail. A buffer structure is constructed, including a metal frame 9 and a buffer device 6. The buffer device 6 can be 3D printed using rubber material, the tension structure 4 can be machined using a CNC machine tool for steel, and the remaining components, such as the launch structure, tension structure, overall bow and arrow structure, and slide, can be 3D printed using resin material.

[0034] Reference Appendix Figure 1 After the structure is connected, an electromagnet is used to attract and stretch the structure 4, causing the slider carrying the hyperelastic shape memory alloy wire to slide along the track, thus stretching the hyperelastic shape memory alloy wire. When the hyperelastic shape memory alloy wire reaches the preset limit, it is launched through the established launch structure 5. The fixed-wing UAV 12 slides along the preset slide 1, and when it reaches the buffer device 6, the slider stops moving, and the fixed-wing UAV 12 is ejected by the impact force, thereby achieving the effect of using the hyperelastic shape memory alloy wire to launch the fixed-wing UAV. By utilizing the self-sensing characteristics of the hyperelastic shape memory alloy wire and measuring its resistance value, the energy density at launch can be obtained, thereby changing the launch performance.

[0035] The above examples illustrate the technical concept and structural features of this invention patent, with the aim of enabling researchers and engineers in the field to understand this invention patent and to realize the product accordingly.

Claims

1. A modular bow-and-arrow type UAV launcher utilizing superelastic shape memory alloy wire, characterized in that: It consists of a modular slideway (1), a modular bow and arrow (2), a shape memory alloy wire (3), a launching structure (5), a buffer structure (6, 9), an "L"-shaped fixing structure (7), a guide rail structure (8, 11), a "middle"-shaped fixing structure (10), and a fixed-wing unmanned aerial vehicle (12); the modular bow and arrow (2), the modular slideway (1), and the modular guide rail (8) are connected in series by a super-elastic shape memory alloy wire (3); after being connected in series, the modular guide rail (8) is passed through the "middle"-shaped fixing structure (10), and the modular bow and arrow (2) is fixed on the upper side of the modular guide rail (8); the metal outer frame (9) of the buffer structure is welded to the inner side of the modular bow and arrow (2), and the buffer rubber (6) is installed into the metal outer frame (9); the "L"-shaped fixing structure (7) is fixed on the modular guide rail (8), and then the modular slideway (1) is connected to the "L"-shaped fixing structure (7); the launching structure (5) includes a trigger structure, a stretching structure, and a pushing structure. The trigger structure includes a spring (F1), a spring baffle (F2), an extension plate (F4), a rotating structure (F5), a trigger wrench (F6), an upper and lower plate fixing structure, and an upper and lower plate. The stretching structure is connected to a slider. The threaded hole on the slider is used to connect the stretching structure (4) to the slider (11), and then the modular guide rail (8) and the through hole on the launching structure (5) are used to connect the launching structure (5) to the modular guide rail (8); the spring (F1) is installed on the rotating structure (F5), and the rotating structure (F5) and the trigger wrench (F6) are installed on the lower plate together; the upper and lower plates are connected by the upper and lower plate fixing structure, and finally the fixed-wing unmanned aerial vehicle (12) is installed on the modular slideway (1); The modular bow and arrow is connected in series by a super-elastic shape memory alloy wire. Nut holes (B2) and variable cross-section holes (B1) are pre-set at the end segments of the modular bow and arrow. After connection, two hex nuts are embedded in the nut holes (B2) of the end segments of the modular bow and arrow. After the alloy wire passes through the variable cross-section hole (B1), it then passes through the hole (C1) of the bolt, winds around the bolt rod several times, the alloy wire is pressed by a gasket (B3), and then the hex nut (C2) and the bolt (C3) are tightened; the modular bow and arrow (2), the modular guide rail (8), and the slideway are connected in series by a super-elastic shape memory alloy wire (3). The length of the super-elastic shape memory alloy wire (3) is adjusted by adjusting the number of segments of the bow and arrow. Correspondingly, the lengths of the modular slideway (1) and the modular guide rail (8) are changed by changing the number of segments; In the connection and fixing structure between the bow and arrow and the guide rail, in the "middle"-shaped fixing structure (10), a guide rail groove (Z4) is opened on the side, and three identical through holes (Z1) are opened on the upper part. A threaded hole (Z3) is opened in the guide rail groove (Z4). The modular guide rail (8) passes through the guide rail groove (Z4). The "middle"-shaped fixing structure (10) is connected to the guide rail through three identical through holes (Z1), and is connected to the middle section of the bow and arrow through the threaded hole (Z3); part of the metal outer frame (9) of the "middle"-shaped fixing structure (10) is welded to the buffer structure. The buffer rubber (6) is placed into the metal outer frame (9) to achieve the buffering effect; in the launching structure, the guide rail and the launching structure are connected through the extension plate (F4) and the preset holes on the extension plate (F4).

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