Bistable collaborative grabbing device of programmable energy barrier based on drone inhabitation

Abstract

The invention belongs to the technical field of mechanical grippers, and discloses a programmable energy barrier bistable collaborative gripping device based on drone inhabitation, comprising: a mounting plate having a guide cylinder; the tops of the two elastic plates are fixed at the two side ends of the mounting plate respectively; the telescopic air pipe is connected between the two elastic plates, and the air pressure of the telescopic air pipe is programmed on line so as to program the energy potential barrier of the bistable structure; one ends of the two connecting side plates are hinged to the bottoms of the two elastic plates respectively, and claws are installed on the two connecting side plates; the two sides of the trigger plate are hinged to the other ends of the two connecting side plates correspondingly, and an impact table is fixed to the trigger plate; the pushing electric push rod is fixed to the top end face of the trigger plate, a cylindrical shell of the pushing electric push rod is slidably connected with the guide cylinder in an inserted mode, and the tail end of a telescopic rod of the pushing electric push rod can abut against the cylinder bottom of the guide cylinder. By means of the device, stable absorption of various impact speeds in the inhabiting and capturing process and rapid closing of the claws can be achieved.

Description

Technical Field

[0001] This invention relates to the field of mechanical gripper technology for unmanned aerial vehicles (UAVs), and more specifically to a bistable cooperative gripping device based on a programmable energy barrier for UAV habitat, used for UAV habitat and object capture. Background Technology

[0002] Due to their small size, low cost, and high operability, drones have been widely used in military warfare, power line inspection, geographic surveying, and aerial photography. As an important piece of equipment for both military and civilian use, drones are considered a key indicator of a nation's aviation industry level and technological progress. However, multi-rotor drones typically face a common critical problem in practical operation: limited flight time. This is mainly due to their low aerodynamic efficiency and limited battery capacity; commercial drones typically have a flight time of less than 30 minutes.

[0003] One promising solution is to learn from biological aviators (such as birds) to perch on desired objects. In nature, the ability to perch is crucial for most birds to hunt prey, monitor territory, and recover energy. Inspired by bird behavior, a "resting" mode provided by perching devices could allow drones to remain stationary and consume less power, even enabling wireless charging. In this context, perching behavior could significantly extend the runtime of drones for tasks such as long-duration aerial surveillance, autonomous detection, and environmental interaction.

[0004] However, due to the complexity and unpredictability of nature, birds often land at dynamically changing speeds, making stable perching of drones a challenge. The difficulty in aerial grasping / perching lies in the high probability of collision between the drone's claws and the target perch. For successful grasping, the robotic claws must smoothly absorb the impact energy and close quickly to form a tight contact with the target. Furthermore, the ability to increase grip strength after landing, similar to birds, based on external factors (such as wind or rain), is also crucial for drones to achieve long-term, stable perching.

[0005] Literature review reveals that existing technologies for drone territorial landing often struggle to simultaneously achieve three key aspects: stable impact energy absorption, rapid claw closure, and programmable gripping force after landing. Literature such as "Compliant BistableGrippers Enable Passive Perching for Micro Aerial Vehicles," "Passive Perching with Energy Storage for Winged Aerial Robots," "Design and Testing of a Bioinspired Lightweight Perching Mechanism for Flapping-Wing UAVs," and Chinese invention patent application number "202311717495.5" propose various drone territorial landing devices based on bistable structures. These devices can close rapidly after a landing impact. However, the closing force of these bistable structures cannot be effectively adjusted according to the impact energy of the drone. That is, too slow an impact speed may prevent the territorial landing device from closing, while too fast an impact speed may prevent the device from smoothly offsetting the energy, resulting in secondary rebound and failed grasping. In fact, the sensitivity of most existing bistable structure-based territorial landing devices to external stimuli largely depends on the structural parameters, materials, and actuation methods preset in the initial design stage. Once a bistable actuator is manufactured, its function and performance cannot be changed. The paper "Perching and Grasping using a passive dynamic bioinspired gripper" proposes a passive perching device with an electrically charged stick-locking clutch. By adjusting the stiffness of the locking mechanism before perching, it can smoothly absorb impact energy at different speeds. However, the gripping force of this device is not adjustable after perching, and because it is a combination of tendon and clutch structure (a non-steady-state structure), it needs to remain energized and locked, increasing energy consumption after perching. Summary of the Invention

[0006] Based on this, this invention develops a "rigid-flexible coupling" bistable cooperative grasping device based on a programmable energy barrier for UAV roosting, used for UAV roosting and object capture. It overcomes the limitation of most previous bistable structures having unchangeable driving performance. By adjusting the energy barrier of the bistable structure, it achieves smooth absorption of various impact velocities during roosting and capture, and rapid claw closure. Furthermore, after roosting, the bistable structure not only locks onto the body, reducing energy consumption, but its gripping force can also be further increased according to the external environment, ensuring robustness during roosting.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A bistable cooperative grasping device based on a programmable energy barrier for UAV habitat includes:

[0009] Mounting plate, which can be mounted on a drone, has a guide tube in the middle of the mounting plate;

[0010] Two elastic plates are provided, with their tops fixed to the two sides of the mounting plate, respectively.

[0011] A telescopic air tube, which is connected between the two elastic plates, allows the energy barrier of the bistable structure to be programmed online by programming the air pressure in the telescopic air tube.

[0012] Two connecting side plates are provided, one end of which is hinged to the bottom of the two elastic plates respectively, and claws are installed on both connecting side plates.

[0013] A trigger plate, the two sides of which are respectively hinged to the other ends of the two connecting side plates, and an impact platform that contacts the tree is fixed on the bottom surface of the trigger plate;

[0014] The push electric push rod is a cylindrical structure that is fixed on the top surface of the trigger plate. The cylindrical housing of the push electric push rod is slidably inserted into the guide cylinder, and the end of the telescopic rod of the push electric push rod can abut against the bottom of the guide cylinder.

[0015] in,

[0016] Initially, the telescopic rod of the push-up electric push rod extends, driving the trigger plate to move downward, which in turn causes the two connecting side plates to swing outward away from the mounting plate, forming a "V" shape. The two claws are in an open state. At this time, the end of the telescopic rod of the push-up electric push rod disengages from the bottom of the guide cylinder and applies negative pressure to the telescopic air tube, causing the telescopic air tube to contract and causing the two elastic plates to bend inward. This state is defined as the open state of the device.

[0017] When the drone lands on a tree to rest, the impact force generated by the resting action strikes the impact platform upwards. The impact platform moves upwards and causes the two connecting side plates to swing inwards towards the mounting plate, making the connecting side plates parallel to the mounting plate. At this point, the state is critical. If the impact platform continues to move upwards, the trigger plate can undergo a transient transition, causing the two connecting side plates to transiently transition into a "^" shaped structure. This causes the two claws to quickly close and hug the tree. This state is defined as the closed state of the device.

[0018] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a bistable cooperative grasping device based on a programmable energy barrier for UAV roosting. This device can quickly close and tighten around the roost (the roost refers to the tree where the UAV roosts) during roosting, thereby improving the success rate and effect of grasping. Furthermore, by programming (programming means "adjustable") the air pressure of the telescopic air tube, the energy barrier of the bistable structure's elastic plate can be adjusted (increased or decreased), thus smoothly absorbing (counteracting) different landing impact energies. In addition, after roosting, the device can lock itself with zero power consumption in the absence of external interference, saving energy. When there is external interference (such as wind, bird strikes, etc.), it can also increase the energy barrier to secure the fuselage. Furthermore, the cylindrical housing of the push-up electric actuator is slidably inserted into the guide cylinder, allowing the guide cylinder to vertically guide the push-up electric actuator. This ensures that when the bistable structure is triggered, it can only be triggered in a specific straight up-and-down manner, maximizing the effectiveness of the bistable structure. Moreover, the claws of the device are triggered to close by impact force to achieve perching, and the claws can be switched from the closed state to the open (spread) state by extending the telescopic rod of the push electric push rod to push against the mounting plate, which can achieve continuous perching (landing-take-off, re-landing, etc.).

[0019] Therefore, this device overcomes the limitation of most previous bistable structures having unchangeable driving performance. By adjusting the energy barrier of the bistable structure, it achieves smooth absorption of various impact velocities during resting and capture, and rapid claw closure. Furthermore, after resting, the bistable structure not only locks the body in place, reducing energy consumption, but its grip strength can also be further increased according to the external environment, ensuring stability during resting.

[0020] Furthermore, the elastic plate is an FR4 fiberglass board.

[0021] The beneficial effects of adopting the above technical solution are: FR4 fiberglass board can withstand greater bending and has good recoverability.

[0022] Furthermore, the telescopic air tube is a rigid-flexible coupling tube, which includes:

[0023] A bellows, wherein end caps are respectively installed at both ends of the bellows, and the end caps are rotatably connected to the elastic plate through a rotating shaft assembly;

[0024] A rigid telescopic shaft is located inside the bellows, and its two ends are fixedly connected to the two end caps respectively.

[0025] One of the end caps is equipped with an air nozzle, through which positive or negative pressure can be applied to the bellows.

[0026] The beneficial effects of adopting the above technical solution are as follows: Due to the buckling effect, a simple bellows may experience instability under load. Therefore, this invention incorporates a rigid-flexible coupling design for the bellows, namely, adding a rigid telescopic shaft inside the bellows. When the bellows is inflated (positive pressure) or deflated (negative pressure) and elongates or shortens, the rigid telescopic shaft not only elongates or shortens simultaneously with the bellows but also improves the rigidity of the bellows, preventing buckling and increasing the output force of the bellows, thereby effectively altering the energy barrier. Furthermore, the bellows and the elastic plate cannot be rigidly fixed but need to be connected via a rotating shaft assembly. This is because the rigid telescopic shaft inside the bellows allows the bellows to only perform linear motion. When the bellows contracts or expands, the rotational connection between the two allows the elastic plate to bend inward or expand outward normally.

[0027] Furthermore, the rotating shaft assembly includes:

[0028] The first clamping plate is fixedly connected to the end cap by bolts;

[0029] A rotating shaft, one end of which is fixedly connected to the first clamping plate;

[0030] The second clamping plate is fixedly connected to one side of the elastic plate, and a bearing is fixedly mounted on the second clamping plate. The other end of the rotating shaft is fixedly connected to the inner ring of the bearing.

[0031] The beneficial effects of adopting the above technical solution are: simple structure and easy quick assembly and disassembly of corrugated pipe and elastic plate.

[0032] Furthermore, the rigid telescopic shaft includes:

[0033] A rigid cylinder, one end of which is fixedly connected to one of the end caps, and a first linear bearing is fixed inside the other end of the rigid cylinder.

[0034] A rigid rod, one end of which is fixedly connected to another end cap, and the other end of which is slidably inserted into the first linear bearing.

[0035] The beneficial effects of adopting the above technical solution are as follows: when the bellows elongates or shortens, the internal rigid rod moves within the rigid cylinder, thereby changing the length of the rigid telescopic shaft, allowing the bellows to elongate and shorten normally. Furthermore, the inclusion of the first linear bearing reduces the frictional resistance during the sliding of the rigid rod, improves the smoothness of its movement, and thus ensures the stability of the bellows' elongation and contraction.

[0036] Furthermore, the corrugated tube is made by silicone injection molding. Specifically, silicone is poured into a mold to obtain an injection molded part with a corrugated PVA inner core. The injection molded part is then placed in a warm water bath to melt the PVA inner core, thus obtaining the corrugated tube.

[0037] The beneficial effects of adopting the above technical solution are as follows: Considering that the inner core is difficult to remove from the injection-molded part, the inner core is made of water-soluble PVA material. The corrugated pipe can be easily obtained by placing the injection-molded part in a warm water bath to melt the PVA material of the inner core. Therefore, corrugated pipes can be conveniently manufactured using this method.

[0038] Furthermore, a second linear bearing is fixed inside the guide cylinder, and the cylindrical housing of the pusher electric push rod is slidably inserted into the second linear bearing.

[0039] The beneficial effects of adopting the above technical solution are: it can reduce the frictional resistance when the electric push rod slides in the guide cylinder, making the electric push rod move up and down more smoothly.

[0040] Furthermore, the claw is a flexible claw made of thermoplastic polyurethane elastomer material through 3D printing.

[0041] The beneficial effects of adopting the above technical solution are: the claw has a certain degree of flexibility and will undergo passive deformation under the weight of the drone, thus having good adaptability to branches of different sizes.

[0042] Furthermore, the gripping surface of the claw is provided with a high-friction silicone layer.

[0043] The beneficial effects of adopting the above technical solution are: the high-friction silicone layer can increase the friction of the claw when gripping the tree, thus achieving stable gripping.

[0044] Furthermore, a cushioning sponge is provided on the bottom surface of the impact platform.

[0045] The beneficial effects of adopting the above technical solution are: the cushioning sponge can be used for initial shock absorption, reducing the vibration generated when the drone grabs trees during landing and improving the stability when landing. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0047] Figure 1This is a first-view structural diagram of the three-dimensional structure of the bistable cooperative grasping device based on a programmable energy barrier for UAV habitat provided by the present invention in the activated state.

[0048] Figure 2 for Figure 1 A schematic diagram of the main structure.

[0049] Figure 3 for Figure 2 A schematic cross-sectional view of the mid-section AA.

[0050] Figure 4 This is a second-view structural schematic diagram of the three-dimensional structure of the bistable cooperative grasping device based on a programmable energy barrier for UAV habitat provided by the present invention in the activated state.

[0051] Figure 5 for Figure 4 A magnified schematic diagram of the structure of part A in the middle.

[0052] Figure 6 This is a schematic diagram of the three-dimensional structure of the bistable cooperative grasping device based on a programmable energy barrier for UAV habitat provided by the present invention in the off state.

[0053] Figure 7 for Figure 6 A schematic diagram of the main structure.

[0054] Figure 8 for Figure 7 A schematic cross-sectional view of the mid-section BB.

[0055] Figure 9 This is a three-dimensional structural diagram of a telescopic trachea.

[0056] Figure 10 This is a schematic diagram of the main structure of the telescopic trachea.

[0057] Figure 11 for Figure 10 A schematic cross-sectional view of the midsection CC.

[0058] Figure 12 This is a schematic diagram of the mold used for injection molding of bellows.

[0059] Figure 13 This is a schematic diagram of the corrugated pipe injection molding process.

[0060] Figure 14 (a) is a simplified diagram of the structure when the trachea contracts inward due to negative pressure.

[0061] Figure 14 (b) is a simplified diagram of the structure when the trachea expands outward due to positive pressure inside.

[0062] Figure 15The curves showing the change in the energy barrier of the claw when positive and negative air pressure is applied to the bellows.

[0063] Figure 16 This is a schematic diagram of the claw's structure. Detailed Implementation

[0064] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0065] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0066] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0067] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0068] The design principle of a robotic claw system should be to close quickly upon impact with a perch and apply sufficient force to smoothly offset the impact energy. Furthermore, to enable long-term monitoring tasks, the subsequent perching process should minimize power consumption. Inspired by bird claws, this invention designs a bistable claw system with a reprogrammable energy barrier. It has two stable states: open and closed. When triggered by an external impact (i.e., upon landing on a tree), the claw transitions from the open state to the closed state, thus achieving perching. Due to its bistable topology, this robotic claw possesses impact release and self-locking functions.

[0069] See details Figures 1-16 This invention discloses a bistable cooperative grasping device based on a programmable energy barrier for unmanned aerial vehicle (UAV) habitat, comprising:

[0070] Mounting plate 1, which can be mounted on the drone, has a guide tube 2 in the middle of the mounting plate 1;

[0071] There are two elastic plates 3, and their tops are respectively fixed to the two sides of the mounting plate 1.

[0072] There are two telescopic air tubes 4, which can be connected between two elastic plates 3 respectively. The energy barrier of the bistable structure can be programmed by online programming of the air pressure of the telescopic air tubes 4.

[0073] There are two connecting side plates 5, one end of which is hinged to the bottom of the two elastic plates 3 respectively. Both connecting side plates 5 are equipped with claws 6.

[0074] The trigger plate 7 is hinged to the other end of the two connecting side plates 5 on both sides. An impact platform 8 that contacts the tree is fixed on the bottom surface of the trigger plate 7. In this way, when perching, the impact force is directly applied to the impact platform 8, and the bistable structure is triggered to close under the action of the impact force.

[0075] The push electric push rod 9 is a cylindrical structure that is fixed on the top surface of the trigger plate 7. The cylindrical shell of the push electric push rod 9 is slidably inserted into the guide cylinder 2, and the end of the telescopic rod 91 of the push electric push rod 9 can abut against the bottom of the guide cylinder 2.

[0076] in,

[0077] Initially, the telescopic rod 91 of the push electric push rod 9 extends, driving the trigger plate 7 to move downward, which in turn causes the two connecting side plates 5 to swing outward away from the mounting plate 1, forming a "V" shape. The two claws 6 are in the open state. At this time, the end of the telescopic rod 91 of the push electric push rod 9 disengages from the bottom of the guide cylinder 2 and applies negative pressure to the telescopic air pipe 4, causing the telescopic air pipe 4 to contract and drive the two elastic plates 3 to bend inward. This state is defined as the open state of the device.

[0078] When the drone lands on a tree to rest, the impact force generated by the resting impacts the impact platform 8 upwards. The impact platform 8 moves upwards and causes the two connecting side plates 5 to swing inwards towards the mounting plate 1, making the connecting side plates 5 parallel to the mounting plate 1. At this time, the state is the critical state. If the impact platform 8 continues to move upwards, the trigger plate 7 can undergo a transient transition, causing the two connecting side plates 5 to transiently transition into a "^" shaped structure, which in turn causes the two claws 6 to quickly close and hug the tree. This state is defined as the closed state of the device.

[0079] In the above embodiments, the elastic plate 3 can be made of FR4 fiberglass board.

[0080] In some embodiments, the telescopic air tube 4 is a rigid-flexible coupling tube, which includes:

[0081] The bellows 41 has end caps 42 installed at both ends, and the end caps 42 are rotatably connected to the elastic plate 3 through the rotating shaft assembly 43.

[0082] Rigid telescopic shaft 44 is located inside bellows 41, and its two ends are fixedly connected to two end caps 42 respectively.

[0083] One of the end caps 42 is equipped with an air nozzle 45, which can apply positive or negative pressure to the bellows 41.

[0084] In some embodiments, the pivot assembly 43 includes:

[0085] The first clamping plate 431 is fixedly connected to the end cap 42 by bolts;

[0086] A rotating shaft 432 is fixedly connected at one end to a first clamping plate 431.

[0087] The second clamping plate 433 is fixedly connected to one side of the elastic plate 3. A bearing 434 is fixed on the second clamping plate 433, and the other end of the rotating shaft 432 is fixedly connected to the inner ring of the bearing 434.

[0088] In some embodiments, the rigid telescopic shaft 44 includes:

[0089] Rigid cylinder 441, one end of rigid cylinder 441 is fixedly connected to one of the end caps 42, and a first linear bearing 442 is fixed inside the other end of rigid cylinder 441.

[0090] A rigid rod 443 is fixedly connected at one end to another end cap 42, and the other end of the rigid rod 443 is slidably inserted into the first linear bearing 442.

[0091] In some embodiments, the corrugated pipe 41 is made by silicone injection molding. Specifically, silicone is poured into the mold 10 to obtain an injection molded part 12 with a corrugated PVA inner core 11. The injection molded part 12 is placed in a 50°C warm water bath to melt the PVA inner core 11 and obtain the corrugated pipe 41.

[0092] In some embodiments, a second linear bearing 13 is fixed inside the guide cylinder 2, and the cylindrical housing of the pusher electric push rod 9 is slidably inserted into the second linear bearing 13.

[0093] In some embodiments, claw 6 is a flexible claw made of thermoplastic polyurethane elastomer material and 3D printed.

[0094] In some embodiments, a high-friction silicone layer 14 is provided on the gripping surface of the claw 6.

[0095] In some embodiments, a cushioning sponge 15 is provided on the bottom surface of the impact table 8.

[0096] This invention designs a rigid-flexible coupled bellows for a bistable claw to create a programmable energy barrier. The principle of the programmable energy barrier is as follows: The bellows is pneumatically driven; when a negative pressure is applied, the bellows contracts, providing an inward clamping force to the bistable system, such as... Figure 14 As shown in (a); conversely, when a positive pressure is applied, the bellows will elongate, thus providing an outward relaxation force to the bistable system, as... Figure 14 As shown in (b). Therefore, when a clamping force is applied, a larger impact force is required to trigger the "open-closed" state transition of the bistable structure. The energy barrier of the bistable structure is programmed by adjusting the air pressure.

[0097] This design offers two main benefits for perching. First, the claws have the ability to preset their own energy barrier based on the drone's descent speed. This prevents the drone from bouncing back after a high-speed impact due to an excessively low energy barrier, and also ensures that the claws won't fail to close during a low-speed descent due to an excessively high energy barrier. Second, birds often actively increase their gripping force when disturbed by external forces. The programmable energy barrier design allows the robot to tighten its claws according to its own state after perching, just like a bird.

[0098] In this invention, the meaning of "cooperation" in the bistable cooperative grasping device based on a programmable energy barrier for UAV habitat is: the device first causes the bistable device to close through passive impact, and after closing, it can further increase the locking force through active fastening (by applying negative pressure to the bellows to achieve active fastening).

[0099] The main advantages of this invention are as follows:

[0100] 1. This invention develops a bistable claw with a reprogrammable energy barrier. Since its energy barrier can be adjusted (increased or decreased), it can smoothly absorb (counteract) different landing impact energies.

[0101] 2. The claws can close quickly while resting.

[0102] 3. Once in place, the device can lock itself in place with zero power consumption, saving energy, provided there is no external interference. In addition, when there is external interference (such as wind or bird strikes), it can also rebuild the energy barrier to secure the device.

[0103] 4. The cylindrical electric actuator serves as a limit and a means of switching back to a steady state. Therefore, it has the ability to perch continuously.

[0104] 5. A design of a bellows with rigid-flexible coupling is proposed, which avoids the buckling phenomenon of the soft actuator, can improve the output force of the bellows, and thus effectively change the energy barrier.

[0105] 6. A flexible claw 3D printed from thermoplastic polyurethane elastomer material was developed, which will passively deform under the weight of the drone, thus having good adaptability to branches of different sizes.

[0106] 7. A method for fabricating soft skin for corrugated pipe structures was proposed.

[0107] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0108] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bistable cooperative grasping device based on a programmable energy barrier for UAV habitat, characterized in that, include: Mounting plate (1), which can be mounted on a drone, and has a guide tube (2) in the middle; Two elastic plates (3) are provided, and their tops are respectively fixed to the two sides of the mounting plate (1). Telescopic air tube (4), which is connected between the two elastic plates (3), can program the energy barrier of the bistable structure by programming the air pressure of the telescopic air tube (4) online; Connecting side plates (5), there are two connecting side plates (5), one end of which is hinged to the bottom of the two elastic plates (3) respectively, and claws (6) are installed on both connecting side plates (5); Trigger plate (7), the two sides of the trigger plate (7) are respectively hinged to the other ends of the two connecting side plates (5), and an impact platform (8) that contacts the tree is fixed on the bottom surface of the trigger plate (7); The push electric push rod (9) is a cylindrical structure and is fixed on the top surface of the trigger plate (7). The cylindrical shell of the push electric push rod (9) is slidably inserted into the guide cylinder (2). The end of the telescopic rod (91) of the push electric push rod (9) can abut against the bottom of the guide cylinder (2). in, Initially, the telescopic rod (91) of the push electric push rod (9) extends, driving the trigger plate (7) to move down, thereby causing the two connecting side plates (5) to swing outward away from the mounting plate (1) and form a "V" shape. The two claws (6) are in an open state. At this time, the end of the telescopic rod (91) of the push electric push rod (9) disengages from the bottom of the guide cylinder (2) and applies negative pressure to the telescopic air pipe (4), causing the telescopic air pipe (4) to contract and causing the two elastic plates (3) to bend inward. This state is defined as the open state of the device. When the drone lands on the tree to rest, the impact force generated by the resting impacts the impact platform (8) upwards. The impact platform (8) moves upwards and causes the two connecting side plates (5) to swing inwards toward the mounting plate (1), making the connecting side plates (5) parallel to the mounting plate (1). At this time, this state is a critical state. The impact platform (8) continues to move upwards, and the trigger plate (7) can undergo a transient transition, causing the two connecting side plates (5) to transiently transition into a "^" shaped structure, thereby causing the two claws (6) to quickly close and hug the tree. This state is defined as the closed state of the device.

2. The bistable cooperative grasping device based on a programmable energy barrier for UAV habitat according to claim 1, characterized in that, The elastic plate (3) is an FR4 fiberglass board.

3. The bistable cooperative grasping device based on a programmable energy barrier for UAV habitat according to claim 1, characterized in that, The telescopic air tube (4) is a rigid-flexible coupling tube, which includes: A bellows (41) is provided with end caps (42) at both ends of the bellows (41), and the end caps (42) are rotatably connected to the elastic plate (3) via a rotating shaft assembly (43). A rigid telescopic shaft (44) is located inside the bellows (41), and both ends of the rigid telescopic shaft (44) are fixedly connected to the two end caps (42) respectively. One of the end caps (42) is provided with an air nozzle (45), through which positive or negative pressure can be applied to the bellows (41).

4. The bistable cooperative grasping device based on a programmable energy barrier for UAV habitat according to claim 3, characterized in that, The rotating shaft assembly (43) includes: The first clamping plate (431) is fixedly connected to the end cap (42) by bolts; A rotating shaft (432), one end of which is fixedly connected to the first clamping plate (431); The second clamping plate (433) is fixedly connected to one side of the elastic plate (3), and a bearing (434) is fixed on the second clamping plate (433). The other end of the rotating shaft (432) is fixedly connected to the inner ring of the bearing (434).

5. The bistable cooperative grasping device based on a programmable energy barrier for UAV habitat according to claim 3, characterized in that, The rigid telescopic shaft (44) includes: A rigid cylinder (441) is provided, one end of which is fixedly connected to one of the end caps (42), and a first linear bearing (442) is fixed inside the other end of the rigid cylinder (441). A rigid rod (443) is provided, one end of which is fixedly connected to another end cap (42), and the other end of which is slidably inserted into the first linear bearing (442).

6. The bistable cooperative grasping device based on a programmable energy barrier for UAV habitat according to claim 3, characterized in that, The corrugated tube (41) is made by silicone injection molding. Specifically, silicone is poured into the mold (10) to obtain an injection molded part (12) with a corrugated PVA inner core (11). The injection molded part (12) is placed in a warm water bath to melt the PVA inner core (11) to obtain the corrugated tube (41).

7. The bistable cooperative grasping device based on a programmable energy barrier for UAV habitat according to any one of claims 1-6, characterized in that, The guide cylinder (2) is fixed with a second linear bearing (13), and the cylindrical housing of the push electric push rod (9) is slidably inserted into the second linear bearing (13).

8. The bistable cooperative grasping device based on a programmable energy barrier for UAV habitat according to any one of claims 1-6, characterized in that, The claw (6) is a flexible claw made of thermoplastic polyurethane elastomer material and 3D printed.

9. The bistable cooperative grasping device based on a programmable energy barrier for UAV habitat according to any one of claims 1-6, characterized in that, The gripping surface of the claw (6) is provided with a high-friction silicone layer (14).

10. The bistable cooperative grasping device based on a programmable energy barrier for UAV habitat according to any one of claims 1-6, characterized in that, The bottom surface of the impact table (8) is provided with a buffer sponge (15).

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