Bidirectional stay wire bionic flapping wing aircraft driven by dielectric elastomer

Abstract

The invention relates to the technical field of soft robots and software driving, in particular to a bionic ornithopter with bidirectional stay wires driven by dielectric elastomers. The problems that an existing bionic flapping wing is insufficient in control and poor in bionic flight stability are solved by aiming at the defects of an exploration and control technology of a micro material of an existing bionic robot. According to the technical scheme, a pair of bionic flapping wings are symmetrically arranged on the two sides of the upper portion of a power bin; a driving device is arranged in the power bin and is composed of six dielectric elastomer units which annularly surround an insulating tube and a compression spring which are coaxially arranged, a first dielectric elastomer clamp is arranged on the rear side of the driving device to divide the driving device into a front part and a rear part, and the dielectric elastomer units are formed by rolling thin films. The front-section dielectric elastomer is coated with an electrode, the rear-section dielectric elastomer is coated at intervals to form a lower semicircle coated electrode, and the upper semicircle is not coated; and a dielectric elastomer clamp II and a dielectric elastomer tail clamp are respectively arranged at the front end and the rear end of the driving device.

Description

Technical Field

[0001] The present invention belongs to the field of soft robots and software driving, and is specifically described as relating to a bionic flapping-wing aircraft driven by a dielectric elastomer and bidirectional pull lines. Background Art

[0002] Dielectric elastomers (DE) are efficient, lightweight, flexible and fast-responding smart materials that can efficiently convert electrical energy into mechanical energy. Combining them with flexible materials is a suitable design approach for bionic aircraft.

[0003] Bionics solves engineering problems by imitating the structure and function of natural organisms, and the study of butterfly flight mechanism is of great significance. The use of dielectric elastomers can simplify the design of bionic butterflies, achieve precise control and rapid response, and improve flight flexibility and endurance. However, flapping wing bionic technology still faces problems of insufficient energy efficiency and endurance in practical applications, and there are difficulties in balancing structural strength and durability, lack of flight stability and control accuracy, high manufacturing costs, poor environmental adaptability, difficulty in multidisciplinary cross-border and many other challenges.

[0004] The use of dielectric elastomers can simplify the design of bionic aircraft, effectively achieve precise control and rapid response, and improve flight flexibility and endurance, while elastic springs provide reliable power support and energy storage. How to effectively combine them to achieve the flexibility and power support of bionic robots is a question that needs to be considered.

[0005] In the design of the bionic flapping wing device using dielectric elastomers, the combination of the control of the individual wings and the pitch motion has not been achieved. The combination with a flexible structure is a possibility to achieve this motion.

[0006] According to Julian Kunze's report in "Design, Manufacturing, and Characterization of Thin Core-Free, Rolled Dielectric Elastomer Actuators", a coreless winding actuator is described, which can make the structure more compact by utilizing the space size, but the structural instability makes this structure unsuitable for reciprocating motion strain.

[0007] According to Marcus Rosenthal's description in "Multifunctional electroelastomer roll actuators and their application for biomimetic walking robots" in 2003, we can know that the spacer film coating method is widely used in MER actuator structures, but the structural form and application range are highly fixed, and the structure is too large and not suitable for micro structures.

[0008] Patent No. CN202110434800.4 discloses a pneumatic folding bionic flapping wing micro-aircraft, which is a bionic flapping wing aircraft of crustaceans. The motor is used to transmit the motion through the crank rocker mechanism to drive the wing surface to flap periodically. The air pump drives the wing surface to extend and open the wing, but the flapping of the wing surface is not independent. The flapping frequency of the two wing surfaces is the same and cannot be controlled separately. Summary of the invention

[0009] In view of this, aiming at the current deficiencies in the exploration and control technology of micro-materials of bionic robots, and in order to solve the problems of insufficient control of existing bionic flapping wings and poor stability of bionic flight, a bionic flapping-wing aircraft driven by a dielectric elastomer and bidirectional pull wire is provided.

[0010] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a bionic flapping-wing aircraft driven by a dielectric elastomer and a bidirectional pull line, comprising a power compartment and a pair of bionic flapping wings, wherein the pair of bionic flapping wings are symmetrically arranged on both sides of the upper part of the power compartment; the power compartment is composed of an upper frame body and a lower frame body that are buckled together; a driving device is arranged inside the power compartment, and fixed pull rings are respectively arranged on both sides of the power compartment, and the pair of bionic flapping wings are respectively flapped by pull lines;

[0011] The driving device is a cylindrical body, which is composed of 6 dielectric elastic rolled driving device units, an insulating tube and a compression spring arranged coaxially around the ring; a dielectric elastomer clamp 1 is arranged on the rear side of the driving device to divide the driving device into two parts, the front and rear parts, the dielectric elastomer of the front section of the driving device unit is coated with an electrode as the driving end, and the rear section of the dielectric elastomer is coated at intervals and rolled to present a lower semicircle coated electrode, and the upper semicircle is not coated; the front and rear ends of the driving device are respectively provided with a dielectric elastomer clamp 2 and a dielectric elastomer tail clip, and the driving device unit where the dielectric elastomer clamp 1 and the dielectric elastomer tail clip are attached is not coated with an electrode;

[0012] The front ends of the six dielectric elastomer units are evenly provided with three tension spring connection blocks, and the front ends of the three tension spring connection blocks are respectively connected with tension springs;

[0013] The pull wire on each bionic flapping wing is sequentially connected to the tension spring, the first composite pull ring, the fixed pull ring and the second composite pull ring on the same side.

[0014] Furthermore, positioning guide pillars are respectively provided in the upper frame and the lower frame, and the positioning guide pillars in the upper and lower frames are plugged into one body. A group of rotating shaft fixing blocks are respectively provided at the left and right ends of the upper surface of the upper frame for the rotation of the bionic flapping wings; an upper driver positioning block and a lower driver positioning block are respectively provided at the center of the upper frame and the lower frame, and an electroelastic clamp is embedded in the grooves of the driver positioning block and the lower driver positioning block, thereby limiting the shaking of the drive device.

[0015] Furthermore, the wing surface of each bionic flapping wing is composed of a PET film and a carbon fiber frame, a thin wire is provided on the upper skeleton of the carbon fiber frame, a double pull ring is sleeved on the thin wire, the double pull rings on the same side of the bionic flapping wing are connected to the pull ring on the same side by a pull wire, and the root of the wing surface of the bionic flapping wing is an I-shaped fixing clip, the lower ends of the I-shaped fixing clip are respectively sleeved with torsion springs and inserted into the coaxially arranged rotating shaft fixing block, one end of the torsion spring is supported on the I-shaped fixing clip, and the spring support foot at the other end is supported on the upper surface of the power compartment.

[0016] Furthermore, the tension spring connecting block is L-shaped, the longitudinal section is arranged perpendicularly to the dielectric elastomer unit, the transverse section extends out of the dielectric elastomer clamp 2, and a circular connecting hole is arranged at the end of the transverse section, and one end of the tension spring is connected to the connecting hole.

[0017] Furthermore, the dielectric elastomer unit is wound centerlessly to achieve equiangular circumferential arrangement around the insulating tube and the compression spring, the dielectric elastomer unit film is made of impact-resistant VHB4910, and the electrode is made of carbon paste.

[0018] Furthermore, a tension spring fixing device is provided on the inner side of the front end of the lower frame, and the other end of the tension spring is connected to the tension spring fixing device.

[0019] Further, the starting angle of rotation of the torsion spring is 135°.

[0020] Furthermore, the length of a single dielectric elastomer is 94 mm, and the thickness of a single layer is 0.5 mm.

[0021] Furthermore, the inner ring of the pull ring is oval and made of metal.

[0022] Furthermore, both the pull line and the thin line are fishing lines.

[0023] Compared with the prior art, the advantages of the present invention are as follows:

[0024] 1. The present invention adopts a rolled dielectric elastomer material to drive, and can achieve reciprocating motion in a straight line direction. The reciprocating motion is more in line with the flapping process of the flapping device.

[0025] 2. The present invention divides the driving device into two groups of drives. The different electric field strengths of the main driving units of the two groups will produce reciprocating motions of different frequencies. The pull wire is connected to the dielectric elastomer driving device unit 20 in the driving device. The pull wire transmits the deformation force of the driving device to the left and right wing surfaces. The flapping frequencies of the left and right wing surfaces will be significantly different, and the different controls of the left and right wings will have more bionic characteristics.

[0026] 3. The pull ring, double pull ring and thin wire of the present invention constitute a simple gain structure, which uses the movement principle of the movable pulley. The main driving section will stretch after power is turned on and shrink after power is turned off. The deformation force generated by the contraction provides the power for the pull wire. Since the length of the pull wire is constant, after the gain structure, the wing surface rotates around the wing root axis under the action of the contraction and elongation of the pull wire, thereby realizing the rapid movement of the wing surface and charging the torsion spring at the same time. The movement of the wing surface is controlled by the pull wire. The present invention also utilizes the deformation properties of flexible materials (deformation of the pull wire, dielectric elastomer, and wing surface film) to always keep the direction of the resultant force of the wing surface moving in the direction of the maximum force. In this way, each flapping is an effective flapping.

[0027] 4. The power compartment of the present invention includes an upper frame and a lower frame, which adopt a hollow design and are injection molded. The structure is more compact, has a strong anti-deformation effect and a large structural rigidity. The hollow design reduces materials and weight and controls costs.

[0028] 5. In order to prevent the abrasion of local components caused by the wire being pulled, the present invention uses a wear-resistant pull ring structure with high hardness.

[0029] 6. The bionic flapping wing of the present invention uses a single-layer PET film and a carbon fiber frame. The wing frame and the wing membrane have good insulation effect, light texture, acid and alkali resistance, and obvious impact resistance.

[0030] 7. The dielectric elastomer unit of the present invention is hollow-wound in sections, so that it has a faster and more stable axial strain, and the hollow rolling can keep the axial stress release uniform and the strain small, and there will be no structural deformation during the reciprocating motion, and the spatial structure can be easily maximized; the drive device unit using this rolling method can realize the combination of reciprocating stretching and contraction and reciprocating swinging motion, and the drive device is composed of 6 dielectric elastomers arranged in parallel in a circular shape. Such an arrangement can improve the problem of insufficient actuation energy of a single drive device unit. At the same time, since each unit is hollow-wound, it will not increase too much mass and volume under parallel conditions, so that the space utilization rate is maximized and the energy release is maximized; the present invention adopts a method of composite parallel connection of multiple dielectric elastomers, which can effectively improve the problem of low energy density compared to a single dielectric elastomer drive.

[0031] 8. The present invention adopts two methods: full coating and interval coating. One section adopts full coating, which can realize reciprocating motion after winding, and the other section adopts interval coating, which can realize swinging motion after winding. The two motion modes are completely different. The type and structure of the actuator are related. This method is to realize the integration of the functions of dielectric elastomer materials. Dielectric elastomer materials are generally independently driven and have a single form of motion. The present invention uses a thin film to achieve two functions through coating and winding, and integrates the swinging and moving functions into one driver. Through this patent, it is possible to integrate dielectric elastomers with different functions into one driver. At the same time, due to the advantage of the unit being hollow, the spatial structure is maximized, and multiple units are connected in parallel, so the structure is more compact, the functions are richer, and the energy release is greater.

[0032] 9. The main part of the present invention utilizes the energy release of the flexible structure dielectric elastomer and the energy storage of the elastic element (elastic spring). It also uses flexible material pull wires, thin ropes, and films to reduce the use of rigid structures. Under collision conditions, the flexible material can improve the impact resistance, which not only improves the flexibility and stability of the aircraft, but also effectively improves the energy conversion efficiency and extends the flight time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of the present invention;

[0034] Figure 2 It is the connection diagram of the power compartment and the drive device;

[0035] Figure 3 This is the explosion diagram of the power compartment;

[0036] Figure 4 is a schematic diagram of the structure of the driving structure, wherein a is a structural diagram of the driving device; b is a structural diagram of the driving device unit;

[0037] Figure 5 It is the front view of the wing structure; a is the wing surface position structure diagram; b is the wire winding position structure diagram;

[0038] Marking instructions: 1. Driving device; 2. Dielectric elastomer tail clip; 3. Lower drive positioning block; 4. Tension spring connecting block; 5 Tension spring; 6. Lower frame; 7. Upper frame; 8. Power compartment positioning guide column; 9. Shaft fixing block; 10. Pull ring; 11. Tension spring fixing device; 12. Upper drive positioning block; 13. Dielectric elastomer clamp 1; 14. Bionic flapping wing; 15. Double pull ring; 16. Thin wire; 17. I-shaped fixation at the wing root; 18. Torsion spring; 19. Compression spring; 20. Driving device unit; 21 Pull wire at the gain structure; 22- Dielectric elastomer clamp 2. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The technical solutions provided by the embodiments of the present invention are described in detail below in conjunction with the drawings.

[0040] The present invention provides a bionic flapping-wing aircraft driven by a dielectric elastomer and a bidirectional pull line, comprising a power chamber and a pair of bionic flapping wings, wherein the pair of bionic flapping wings 14 are symmetrically arranged on both sides of the upper part of the power chamber, and the pair of bionic flapping wings are respectively flapped by pull lines 21, such as Figure 1 shown.

[0041] The power bin is composed of an upper frame 7 and a lower frame 6 that are buckled together; a driving device 1 is arranged inside it, and pull rings 10 are respectively arranged on both sides of the power bin; positioning guide pillars 8 are respectively arranged in the upper frame 7 and the lower frame 6, and the positioning guide pillars 8 in the upper and lower frames are matched and plugged into one body, and a group of rotating shaft fixing blocks 9 are respectively arranged at the left and right ends of the upper surface of the upper frame 7 for the rotation of the bionic flapping wing 14; an upper driver positioning block 12 and a lower driver positioning block 3 are respectively arranged in the center of the upper frame 7 and the lower frame 6, and a dielectric elastomer clamp 13 is embedded in the grooves of the driver positioning block 12 and the lower driver positioning block 3, thereby limiting the shaking of the driving device 1 and ensuring the working stability of the power bin, such as Figure 2 and 3 shown.

[0042] The wing surface of each bionic flapping wing 14 is composed of a PET film and a carbon fiber frame. A thin wire 16 is arranged on the upper skeleton of the carbon fiber frame. A double pull ring 15 is sleeved on the thin wire 16 (the double pull ring 15 is welded by a composite pull ring 15-a and a composite pull ring 2 15-b). The pull wire 21 on the bionic flapping wing on the same side is connected to the composite pull ring 15-a, the fixed pull ring 10 and the composite pull ring 2 15-b on the same side from the tension spring 5 on the same side in sequence. The left and right bionic flapping wings are connected to the tension spring on the same side, and the tension spring at the upper end is not involved; the root of the wing surface of the bionic flapping wing 14 is an I-shaped fixing clamp 17 The two ends of the lower part of the I-shaped fixing clamp 17 are respectively sleeved with torsion springs 18 and inserted into the coaxially arranged rotating shaft fixing block 9. One end of the torsion spring 18 is supported on the I-shaped fixing clamp 17, and the other end of the spring support foot is supported on the upper surface of the power bin; the root of the wing surface 14 can rotate, and each rotating part has a torsion spring structure 18-a, 18-b as an energy storage element to provide restoring force and store energy. The lower part of the wing surface 14 uses a flexible rope to connect multiple force points. The length of the flexible rope is greater than the distance between the two points. When the force is applied to produce deformation, the direction of the resultant force formed by the force at the two points is always toward the transmission along the thin rope, such as Figure 5 shown.

[0043] The rotating shaft of the wing root of the present invention is Φ3×50mm, and the fixed shaft supporting the torsion spring 18 is equidistant from the rotating shaft.

[0044] As an implementation method in this embodiment, the driving device 1 is a cylindrical body, which is composed of 6 dielectric elastomer units arranged in a ring around a 5mm*60mm PET insulating tube coaxially and a compression spring 19 with a diameter of 5mm, and the compression spring 19 provides pre-stretching stress; the rear side of the driving device is provided with a dielectric elastomer clamp 13 to divide the driving device into two parts, front and rear, and the front and rear ends of the driving device are respectively provided with a dielectric elastomer clamp 22 and a dielectric elastomer tail clip 2, and the contact surface between the dielectric elastomer clamp 13, the dielectric elastomer clamp 22 and the dielectric elastomer tail clip 2 and the dielectric elastomer unit is 5mm, and this 5mm is not coated with electrodes and is not processed in any way. The dielectric elastomer unit 20 is driven in different front and rear modes, and the two-stage type can complete the combination of reciprocating motion and swinging around the plane. The longer section of the driving unit is the main driving end, which can realize reciprocating telescopic motion along the axis direction when powered on. The main driving end is connected to the tension spring 5, and the other end is the shorter end. This section can realize a reciprocating swinging motion; the front ends of the six dielectric elastomer units are evenly sandwiched with three tension spring connecting blocks 4, and the front ends of the three tension spring connecting blocks 4 are respectively connected to tension springs 5, such as Figure 4As shown. Since the driving device is composed of multiple units connected in parallel, and the dielectric elastomer unit 20 is divided into two sections, front and rear, by the dielectric elastomer clamp 13, the two sections of the same driver are not evenly divided due to the different actuation effects of the front and rear, which will cause the structure to shake and become unstable. Therefore, the positioning block can fix the position of the driving device 1 and overcome the shaking caused by different movement modes.

[0045] The dielectric elastomer unit is formed by hollow rolling of a film, an electrode is coated on the front section of the dielectric elastomer, and the rear section of the dielectric elastomer is coated at intervals and rolled to present a lower semicircle coated electrode, and the upper semicircle is not coated. The two dielectric elastomer units 20 constitute a group of sets. The stretching spring 5 and the dielectric elastomer unit 20 will generate elastic contraction restoring force after the action. The two pre-stretching stress devices that provide contraction recovery are placed oppositely. The stretching spring 5 will provide pre-stretching stress in the opposite direction of the dielectric elastomer unit 20. Each group is provided with pre-stretching stress by the stretching spring 5 and the stretching spring connecting block 4, such as Figure 4 As shown in a;

[0046] The driving device 1 of the present invention is arranged in an equiangular circle around the PET insulating tube. The length of a single dielectric elastomer is 94 mm, and the thickness of the single-layer film stretched is 0.5 mm. The length of a single dielectric elastomer used for reciprocating drive is 59 mm, the length used for swinging is 25 mm, and the length used for fixing is 5 mm.

[0047] As an implementation method in this embodiment, the tension spring connecting block 4 is L-shaped, such as Figure 4 As shown, the elastic body unit is vertically arranged, and the transverse section extends out of the dielectric elastic body fixture 22. A circular connecting hole is arranged at the end of the transverse section, and one end of the tension spring 5 is connected to the connecting hole.

[0048] As an implementation method in this embodiment, the dielectric elastomer unit is hollow wound and arranged in equal angles around the insulating tube and the compression spring 19. The dielectric elastomer unit film is made of impact-resistant VHB4910, and the electrode uses carbon paste.

[0049] As an implementation method in this embodiment, a tension spring fixing device 11 is provided on the inner side of the front end of the lower frame 6 , and the other end of the tension spring 5 is connected to the tension spring fixing device 11 .

[0050] As an implementation method in this embodiment, the starting angle of rotation of the torsion spring 18 is 135°.

[0051] As an implementation method in this embodiment, the length of a single dielectric elastomer is 94 mm and the thickness of a single layer is 0.5 mm.

[0052] As an implementation method in this embodiment, the inner ring of the pull ring 10 is elliptical and made of metal.

[0053] As an implementation method in this embodiment, the pull line 21 and the thin line 16 are both fishing lines.

[0054] As an implementation method in this embodiment, the upper frame 7 and the lower frame 6 are of the same size, each with a thickness of 2mm, 90mm×30mm×12.5mm, and the structure is made of 3D printing, including a power compartment positioning guide column, a tension spring connecting block, and a driver positioning block.

[0055] The upper driver positioning block 12 and the lower driver positioning block 3 are made as one piece with the frame. The size of the lower driver positioning block 3 is 1mm×3mm×15mm, and the size of the upper driver positioning block 12 is 1mm×7mm×15mm.

[0056] The pull ring 10 is a metal ring with a major axis diameter of 4 mm. The inner diameter of the ring is an ellipse. Compared with a circular structure, it can effectively prevent the pull wire 21 from being worn.

[0057] The diameter of the tension spring fixture 11 is 1m, and the size is 13mm×4mm.

[0058] The dimensions of the torsion spring 18 are: 5.5 mm in diameter, 2 mm in pitch, 6 turns in total, in a clockwise direction, and the starting angle of rotation of the torsion spring is 135°.

[0059] The dimensions of the compression spring 19 are: diameter 4.5 mm, pitch 1 mm, 21 turns in total, clockwise direction, and no starting angle.

[0060] The dimensions of the tension spring 5 are: 7 mm in diameter, 1 mm in pitch, 20.5 turns in total, clockwise direction, and no starting angle.

[0061] The power compartment of the present invention facilitates the installation and disassembly of the driving device of the hollow structure after winding, and is also conducive to heat dissipation. At the same time, compared with the frameless structure, the framed structure is more stable;

[0062] In the driving of the dielectric elastomer material of the present invention, the difference in structure will affect the movement mode of the driving device. The reciprocating motion of the dielectric elastomer along a single axis and the swinging motion around a single axis are combined in a driving device through a process. A part of the reciprocating motion can be directly converted into a rotation around the wing axis through a gain structure, and the movement modes before and after the conversion are similar, with less energy loss and a simple structure. A part of the swinging motion directly realizes the control of the pitch by affecting the pitch motion of the horizontal plane balance control structure, and the pitch response is accurate.

[0063] The present invention adopts segmented hollow winding, and the hollow structure has faster and more stable axial strain. The hollow winding can keep the axial stress release uniform and the strain small, and there will be no structural deformation in the reciprocating motion. At the same time, it is easy to maximize the use of the space structure. The actuator using this winding method can realize more functions. The parallel connection of multiple actuators can also improve the problem of insufficient actuation energy of a single actuator. At the same time, since each unit is hollow rolled, it will not increase too much mass and volume under the condition of parallel connection, so that the space utilization rate is maximized and the energy release is maximized.

[0064] This patent integrates two kinds of thin film coatings. The structures of the two driving parts are completely different, and different actuation modes are realized. This method is to realize the integration of the functions of dielectric elastomer materials. The types and structures of actuators are related. Through this patent, dielectric elastomer drivers with different functions can be integrated into one driver. At the same time, due to the advantage of the unit being hollow, the spatial structure is maximized, and multiple units can be connected in parallel, with a more compact structure, richer functions, and greater energy release.

[0065] Design technical requirements:

[0066] 1. The use of coreless dielectric elastomers can effectively achieve lightweight structures and increase deformation;

[0067] 2. The retraction and release of the rope drives the wing surface to flap. The large stroke movement requires the power compartment to meet a large deformation requirement. Multiple ropes in parallel can meet large deformation requirements.

[0068] 3. Flapping flight is a process that uses the Bernoulli principle to create a pressure difference. Since unidirectional force movement is not easy to achieve movement, dividing the drive unit into two groups can form two groups of different braking frequencies. The flapping of the wing surface forms an effective frequency difference to complete the control of the double wing surface.

[0069] 4. A torsion spring 18 is added to the rotation position of the wing to solve the impact load on the flight device.

[0070] 5. A total of three tension springs 5 ​​can always provide tension force for the drive device during deformation.

[0071] 6. The purpose of choosing a hollow frame structure for the power compartment is to reduce the impact of vibration caused by movement on the overall posture.

[0072] 7. The purpose of using a pull wire is to generate an instantaneous acceleration to drive the wing surface. A low-pressure area will be formed in the area where the movement occurs, and the pressure difference between the upper and lower wing surfaces will meet the requirements for takeoff.

[0073] 8. The cable is flexible, and there will be a delay in the process of transmitting force, which makes it possible to effectively control the instability of the power compartment. At the same time, the force of the flexible cable always moves in the direction of the resultant force.

[0074] Experimental example,

[0075] Every two drive device units 20 drive each other as a group. When the electrodes are energized, the main driving end of the hollow drive device unit 20 stretches due to the action of the electric field force, and the gain structure power is zero, releasing the stress of the single-sided pull wire 21. As the stress is released, the torsion springs 18-a and 18-b connected to the root of the wing begin to restore their deformation. Under the action of the spring restoring force, the wing surface 14 begins to rotate along the rotating shaft 9. The force on the torsion spring foot drives the I-beam support 17 to enable the wing 14 to flap upward. In the power-off state, each drive device 1 will produce a restoring force deformation due to the properties of the dielectric elastomer material. The two drive units act as a group of drivers to drive the thin rope 21 on one side to complete the tightening. Under the pulling action of the gain structure 15 below the wing 14, a downward flapping is completed. The drive device is initially horizontal in space. By applying voltage to the tail end of the drive device unit 20, the dielectric elastomer material moves under the action of the electric field, causing the drive device 1 to swing up and down. The swinging will cause the entire power compartment to swing in the horizontal plane. Controlling the swinging angle can control the deflection in the horizontal plane. In this way, the entire mechanism can be controlled to achieve pitch movement, realizing the flapping bionic flapping and pitching composite control at the same time.

[0076] Experimental state. There are three different states of this structure. The first is the initial state. In this state, the connection and pre-stretching stress of the structure are stable, there is a restoring force inside the torsion spring 18, and the dielectric elastomer material in the drive device 1 has a restoring force. The two restoring forces ultimately act on the pull wire 21, and the two are opposite forces. The length of the pull wire 21 remains unchanged. Under the action of the force, the wing 14 is in a suspended state at this time; in the second state, voltage is applied to the drive device 1 in the power compartment, and the main driving end of the drive device unit 20 is deformed. There are a total of six drive units. These six units are evenly divided into two groups. The two groups can adjust the flapping frequency of the left and right wings respectively. The deformation of each drive group is consistent with the deformation of the rope movement. The torsion spring 18 is used as a Energy storage element, the stored energy is transmitted to the I-beam 17 through the foot of the spring 18, driving the wing surface 14 to produce a rotational motion around the 9-axis hole. At this time, the double-sided wing surfaces 14 can be seen from the front of the structure to perform a recovery action, and the two wing surfaces 14 gradually move closer to each other on the upper part of the structure; in the third transition state, the voltage of the drive unit 20 in the power compartment of the structure is interrupted, and the drive unit 20 produces a recovery deformation, and the pre-stretching stress is fully provided by the tension spring 5. At the same time, it can be observed near this structure that the rope is tightened toward the two sets of drives. The rope outside the power compartment will generate a strong pulling force under the effect of the wing 14 gain due to the tightening force. At this time, the torsion spring 18 is re-energized, and the wing 14 is pulled down. At the same time, the structure will appear to be in a downward closing process.

[0077] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A bionic flapping-wing aircraft driven by a dielectric elastomer and having a bidirectional tension line, comprising a power compartment and a pair of bionic flapping wings, wherein the pair of bionic flapping wings (14) are symmetrically arranged on both sides of the upper part of the power compartment; characterized in that: The power chamber is composed of an upper frame (7) and a lower frame (6) which are buckled together; a driving device (1) is arranged inside the power chamber, fixed pull rings (10) are respectively arranged on both sides of the power chamber, and a pair of bionic flapping wings are respectively flapped by pull wires (21); The driving device (1) is a columnar body, and is composed of 6 dielectric elastic rolled driving device units (20) arranged in a ring around an insulating tube and a compression spring (19) coaxially arranged; a dielectric elastomer clamp (13) is arranged on the rear side of the driving device to divide the driving device into a front and a rear part, the front section of the driving device unit (20) is coated with an electrode on the dielectric elastomer as the driving end, and the rear section of the dielectric elastomer is coated at intervals and rolled to present a lower semicircle coated electrode, and the upper semicircle is not coated; the front and rear ends of the driving device are respectively provided with a dielectric elastomer clamp (22) and a dielectric elastomer tail clip (2), and the driving device unit (20) is not coated with an electrode at the location where the dielectric elastomer clamp (13) and the dielectric elastomer tail clip (2) are attached; The front ends of the six dielectric elastomer units are evenly provided with three tension spring connection blocks (4), and the front ends of the three tension spring connection blocks (4) are respectively connected to tension springs (5); The pull wire (21) on each bionic flapping wing is sequentially connected to the tension spring (5), the composite pull ring 1 (15-a), the fixed pull ring (10) and the composite pull ring 2 (15-b) on the same side.

2. A bionic flapping-wing aircraft driven by a dielectric elastomer and bidirectional pull wire according to claim 1, characterized in that: Positioning guide pillars (8) are respectively arranged in the upper frame (7) and the lower frame (6), and the positioning guide pillars (8) in the upper and lower frames are plugged together. A group of rotating shaft fixing blocks (9) are respectively arranged at the left and right ends of the upper surface of the upper frame (7) for rotating the bionic flapping wing (14); an upper driver positioning block (12) and a lower driver positioning block (3) are respectively arranged at the center of the upper frame (7) and the lower frame (6), and an electroelastic clamp (13) is embedded in the grooves of the driver positioning block (12) and the lower driver positioning block (3), thereby limiting the shaking of the driving device (1).

3. A bionic flapping-wing aircraft with a dielectric elastomer driving a bidirectional pull line according to claim 1 or 2, characterized in that: The wing surface of each bionic flapping wing (14) is composed of a PET film and a carbon fiber frame, a thin wire (16) is arranged on the upper skeleton of the carbon fiber frame, a double pull ring (15) is sleeved on the thin wire (16), the double pull ring (15) on the same side bionic flapping wing (14) is connected to the same side pull ring (10) through a pull wire (21), the root of the wing surface of the bionic flapping wing (14) is an I-shaped fixing clamp (17), the lower two ends of the I-shaped fixing clamp (17) are respectively sleeved with torsion springs (18) and inserted into a coaxially arranged rotating shaft fixing block (9), one end of the torsion spring (18) is supported on the I-shaped fixing clamp (17), and the spring support foot at the other end is supported on the upper surface of the power compartment.

4. The bionic flapping-wing aircraft driven by a dielectric elastomer and bidirectional pull wire according to claim 3, characterized in that: The tension spring connection block (4) is L-shaped, with a longitudinal section arranged perpendicularly to the dielectric elastomer unit, a transverse section extending out of the second dielectric elastomer clamp (22), and a circular connection hole being arranged at the end of the transverse section, and one end of the tension spring (5) being connected to the connection hole.

5. The bionic flapping-wing aircraft with a dielectric elastomer driving a bidirectional pull line according to claim 4, characterized in that: The dielectric elastomer unit is wound centerlessly and arranged in equal angles around the insulating tube and the compression spring (19). The dielectric elastomer unit film is made of impact-resistant VHB4910, and the electrode is made of carbon paste.

6. The bionic flapping-wing aircraft driven by a dielectric elastomer and bidirectional tension wire according to claim 5, characterized in that: A tension spring fixing device (11) is provided on the inner side of the front end of the lower frame (6), and the other end of the tension spring (5) is connected to the tension spring fixing device (11).

7. The bionic flapping-wing aircraft driven by a dielectric elastomer and bidirectional pull wire according to claim 6, characterized in that: The starting angle of rotation of the torsion spring (18) is 135°.

8. The bionic flapping-wing aircraft with a dielectric elastomer driving a bidirectional pull line according to claim 7, characterized in that: The length of a single dielectric elastomer is 94 mm, and the thickness of a single layer is 0.5 mm.

9. The bionic flapping-wing aircraft driven by a dielectric elastomer and bidirectional pull wire according to claim 8, characterized in that: The inner ring of the pull ring (10) is elliptical and made of metal.

10. The bionic flapping-wing aircraft with a dielectric elastomer driving a bidirectional pull line according to claim 9, characterized in that: The pulling line (21) and the thin line (16) are both fishing lines.

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