Multi-mode bistable flexible gripper for water-air amphibious unmanned aerial vehicle

Abstract

The invention relates to the technical field of manipulators, and particularly discloses a multi-mode bistable flexible gripper for a water-air amphibious unmanned aerial vehicle, which comprises a base, a rope-driven soft finger, a bistable actuating mechanism and a trigger, the at least two rope-driven soft fingers are rotatably arranged on the base; the at least one bistable actuating mechanism is fixedly arranged on the base, and the bistable actuating mechanism and the trigger control the at least two rope-driven soft fingers to grab and release articles; the multi-mode bistable flexible gripper for the water-air amphibious unmanned aerial vehicle has a bistable characteristic, and is matched with two operating mechanisms of gripping and suction, so that the multi-mode operating capability is achieved, and the multi-mode bistable flexible gripper is suitable for gripping more kinds of objects and more complex environments.

Description

Technical Field

[0001] The present invention relates to the technical field of manipulators, and in particular to a multi-mode bistable flexible gripper for water-air amphibious unmanned aerial vehicles. Background Art

[0002] Amphibious drones have the characteristics of wide working range, strong environmental adaptability, and convenient deployment. Combining the operation capabilities of amphibious drones with robot grippers will further expand the application scope of amphibious drones, such as aerial perching and landing and underwater non-destructive sampling. In the aerial environment, the drone gripper needs to have a fast response mechanism to quickly grab branches or other natural structures to help the drone take off and land stably and reliably to complete the perching. In the underwater environment, the drone gripper is required to be flexible and adaptable to achieve non-destructive sampling of fragile organisms.

[0003] Obviously, the requirements for aerial habitat and underwater biological sampling are different, so a gripper suitable for both air-water and water-based amphibious drones needs to be designed. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a multi-mode bistable flexible gripper for water and air amphibious unmanned aerial vehicles, which has bistable characteristics and is equipped with two operating mechanisms, namely, grasping and sucking. Therefore, it has multi-mode operation capability and is suitable for grasping more types of objects and more complex environments.

[0005] To solve the above problems, the present invention adopts the following technical solutions:

[0006] An embodiment provides a multi-mode bistable flexible gripper for an amphibious aerial drone, comprising: a base, at least two rope-driven soft fingers, at least one bistable actuating mechanism, and at least one trigger.

[0007] The at least two rope-driven soft fingers are rotatably arranged on the base.

[0008] The at least one bistable actuating mechanism is fixedly disposed on the base.

[0009] In some working modes, the at least one bistable actuation mechanism is used to self-actuate the at least two rope-driven soft fingers to grasp and release an object.

[0010] In some working modes, the at least one bistable actuating mechanism is configured to be triggered by the at least one trigger, so that the at least one bistable actuating mechanism actuates the at least two rope-driven soft fingers to grasp and release an object.

[0011] In some working modes, the at least one bistable actuating mechanism is provided with a partial triggering force by the at least one trigger when the at least one bistable actuating mechanism actuates the at least two rope-driven soft fingers to grasp and release an object.

[0012] Wherein, at least one adsorption mechanism is arranged on the trigger for adsorbing objects.

[0013] In the multi-mode bistable flexible gripper for an amphibious aerial drone provided by at least one embodiment of the present disclosure, the bistable actuator has an open steady state and a closed steady state, and the bistable actuating mechanism includes: a flexible member and at least two fixers.

[0014] The flexible member has a driving air cavity, an air hole and at least two first trigger blocks.

[0015] The at least two fixers are arranged at the bottom of the flexible member.

[0016] The driving air cavity is communicated with the air hole.

[0017] The at least two first trigger blocks are located at the bottom of the flexible member.

[0018] The at least two rope-driven soft fingers have driving ropes, and the driving ropes of the at least two rope-driven soft fingers are connected one by one to the at least two fixers.

[0019] When the driving air cavity is adjusted to a negative pressure and causes the flexible member to contract, the at least two first trigger blocks guide the contraction of the flexible member.

[0020] When the driving air cavity is adjusted to a negative pressure and causes the flexible member to contract, the at least two fixers are configured to gradually move closer together as the flexible member contracts, causing the rope-driven soft fingers to perform a grasping action.

[0021] In the multi-mode bistable flexible gripper for an amphibious aerial drone provided by at least one embodiment of the present disclosure, the bistable actuating mechanism further includes: at least one elastic element.

[0022] The at least one elastic element is stretched and fixedly disposed on the at least two fixtures.

[0023] The first trigger block has a contact surface, and the contact surfaces of adjacent first trigger blocks contact each other to balance the elastic force of the at least one elastic element.

[0024] When the adjacent first trigger block guides the contraction of the flexible member, the at least one elastic element releases the stored elastic potential energy to provide kinetic energy for the movement of the trigger.

[0025] In the multi-mode bistable flexible gripper for an amphibious aerial drone provided in at least one embodiment of the present disclosure, a connecting shaft is provided at the bottom of the flexible member, and the connecting shaft is used to provide support for the bottom of the flexible member.

[0026] The fixer is fixedly connected to the connecting shaft, and the connecting shaft is located on the side of the first trigger block.

[0027] In the multi-mode bistable flexible gripper for an amphibious aerial drone provided by at least one embodiment of the present disclosure, the trigger includes: a connecting frame.

[0028] The connecting frame is configured to be slidably connected to the base.

[0029] The second trigger block is fixedly configured on the connecting frame.

[0030] The second trigger block is located below the first trigger block, and the second trigger is used to collide with the bottom of the flexible member to change the bistable actuator from an open stable state to a closed stable state.

[0031] The adsorption mechanism is fixedly arranged on the connecting frame and / or the connecting frame.

[0032] In the multi-mode bistable flexible gripper for an amphibious aerial drone provided in at least one embodiment of the present disclosure, the first trigger block is in the shape of a triangular prism, and the bottom surface of the first trigger block serves as the abutment surface.

[0033] There is an even number of the first trigger blocks, every two of the first trigger blocks form a group, and the two first trigger blocks in each group are symmetrically arranged.

[0034] The adjacent first trigger blocks are arranged on the inner bottom surface of the driving air cavity with their bottom surfaces abutting against each other.

[0035] One side surface of the first trigger block is fixedly connected to the inner bottom surface of the driving air cavity.

[0036] In the multi-mode bistable flexible gripper for an amphibious aerial drone provided by at least one embodiment of the present disclosure, the rope-driven soft finger comprises: a finger body, an exoskeleton and a fingertip.

[0037] The finger body has a mounting groove.

[0038] The outer frame is inserted into the mounting groove.

[0039] The fingertip is fixedly arranged at the end of the finger body.

[0040] The outer frame is provided with perforations, and the outer frame and the mounting grooves are both provided with a plurality of holes, and the plurality of mounting grooves are distributed at equal intervals, and the outer frame is fixedly connected to the finger body.

[0041] The drive rope passes through the through hole.

[0042] One end of the driving rope is fixed on the outer frame adjacent to the fingertip, and the other end of the driving rope is fixed on the fixer.

[0043] In the multi-mode bistable flexible gripper for an amphibious water-air drone provided in at least one embodiment of the present disclosure, a guide rail is provided on the base, a slider is provided on the connecting frame, and the base and the connecting frame are slidably connected via the guide rail and the slider.

[0044] In the multi-mode bistable flexible gripper for an amphibious aerial drone provided in at least one embodiment of the present disclosure, the top of the flexible member is fixedly connected to the base.

[0045] In the multi-mode bistable flexible gripper for an amphibious aerial drone provided by at least one embodiment of the present disclosure, the first trigger block is an elastomer.

[0046] The beneficial effects of the present invention are:

[0047] It has multiple working modes including passive trigger quick grasp, active trigger quick grasp, active trigger gentle grasp, and adsorption mode. The passive trigger quick grasp can also achieve adjustable sensitivity, thus helping drones cope with more diverse tasks.

[0048] The overall structure is relatively simple. The movement of the gripper can be regulated by combining a micro air pump and a pressure regulating valve. The control is simple and the installation integration is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 It is a stereoscopic diagram of a multi-mode bistable flexible gripper for an amphibious aerial drone in an embodiment.

[0051] Figure 2 A schematic diagram of the structure of the base.

[0052] Figure 3 Schematic diagram of the structure of the rope-driven soft finger.

[0053] Figure 4 It is a schematic diagram of the structure of the finger body.

[0054] Figure 5 Schematic diagram of the structure of the exoskeleton.

[0055] Figure 6 Schematic diagram of the structure of a bistable actuator.

[0056] Figure 7 This is a cross-sectional view of the flexible part.

[0057] Figure 8 It is a structural diagram of the flexible part.

[0058] Fig. 9 A schematic diagram of the structure of the fixator.

[0059] Fig.10 Schematic diagram of the steady-state transition of the multi-mode bistable flexible gripper used for the water-air amphibious UAV in this embodiment.

[0060] Fig.11 A schematic diagram of the trigger structure.

[0061] Fig.12 Schematic diagram of the structure of the second trigger block.

[0062] Fig.13 It is a cross-sectional view of the adsorption mechanism.

[0063] Fig.14 Schematic diagram of a passively triggered rapid grasping mode of a multi-mode bistable flexible gripper for an amphibious aerial drone in an embodiment.

[0064] Fig.15 Schematic diagram of an actively driven rapid grasping mode of a multi-mode bistable flexible gripper for an amphibious aerial drone in an embodiment.

[0065] Fig.16 Schematic diagram of an actively driven gentle grasping mode of a multi-mode bistable flexible gripper for an amphibious aerial drone in an embodiment.

[0066] Fig.17 Schematic diagram of a suction mode of a multi-mode bistable flexible gripper for an amphibious aerial drone in an embodiment.

[0067] Fig.18 Schematic diagram of a grabbing and suction hybrid mode of a multi-mode bistable flexible gripper for an amphibious water-air drone in an embodiment.

[0068] In the figure:

[0069] 100, base; 110, mounting hole; 120, tracheal jack; 130, guide rail; 140, finger mounting position;

[0070] 200, rope-driven soft finger; 210, finger body; 211, mounting groove; 220, outer frame; 221, perforation; 222, clamping hole; 230, driving rope; 240, fingertip;

[0071] 300, bistable actuator; 310, flexible member; 311, mounting hole; 312, shaft hole; 313, air hole; 320, first trigger block; 330, connecting shaft; 340, fixer; 341, assembly hole; 342, slot; 343, rope fixing hole; 350, elastic element;

[0072] 400, trigger; 410, connecting frame; 411, second trigger block; 412, slider; 420, adsorption mechanism; 421, suction cup air inlet; 422, suction cup air outlet. DETAILED DESCRIPTION

[0073] The technical solutions in the embodiments will be described clearly and completely below in conjunction with the drawings in the embodiments. Obviously, the described embodiments are only a part of the embodiments, rather than all the embodiments.

[0074] like Figure 1 As shown, this embodiment provides a multi-mode bistable flexible gripper for water and air amphibious UAVs, including a base 100, a rope-driven soft finger 200, a bistable actuator 300, and a trigger 400. The coordinated cooperation of the rope-driven soft finger 200 and the bistable actuator 300 ensures the rapidity and flexibility of grasping, and the trigger 400 can not only trigger the adsorption mechanism on the bistable actuator 300 under the action of an external force, but also independently complete the adsorption and desorption of an object.

[0075] like Figure 2 As shown, the base 100 is made of photosensitive resin 3D printing, and the base 100 has a mounting hole 110, an air pipe socket 120, a guide rail 130 and a finger mounting position 140. Among them, the mounting hole 110 is used to cooperate with the bolt to install the bistable actuator 300. One end of the external air pipe passes through the base 100 through the air pipe socket 120, and the other end of the external air pipe is connected to the air pump. The guide rail 130 provides guidance for the trigger 400, and the rope-driven soft finger 200 is fixed on the base 100 through the finger mounting position 140.

[0076] Figure 3 , Figure 4 , Figure 5 As shown, the rope-driven soft finger includes a finger body 210 , an outer skeleton 220 , a driving rope 230 and a fingertip 240 .

[0077] The finger body 210 has a mounting groove 211; the fingertip 240 is fixedly arranged at the end of the finger body 210; wherein, a through hole 221 is provided on the exoskeleton 220, and the exoskeleton 220 and the mounting groove 211 are both provided with a plurality of mounting grooves 211, and the plurality of mounting grooves 211 are evenly spaced, and the exoskeleton 220 is fixedly connected to the finger body 210; the driving rope 230 passes through the through hole 221; one end of the driving rope 230 is fixed on an exoskeleton 220 adjacent to the fingertip 240, and the other end of the driving rope 230 is fixed on the fixer 340.

[0078] The outer frame 220 has a locking hole 222 , through which the finger 210 passes, and the outer frame 220 is partially inserted into the installation groove 211 .

[0079] like Figure 6 , Figure 7 , Figure 8 , Fig. 9 As shown, the bistable actuator 300 includes a flexible member 310, a first trigger block 320, a connecting shaft 330, a fixing device 340 and an elastic element 350. The flexible member 310 is formed of silicone and has a driving air cavity, a mounting hole 311, an axis hole 312 and an air hole 313. The first trigger block 320 is a triangular prism-shaped elastic block, two of which are bonded to the inner bottom surface of the flexible member 310 by a silicone adhesive in a posture where the bottom surfaces of the triangular prisms are against each other. The two connecting shafts 330 are respectively inserted into the two sides of the bottom of the flexible member 310 through the two axis holes 312. Each connecting shaft 330 has a fixing device 340 at both ends, and the fixing devices 340 are fixed together through the assembly hole 341. The fixing device 340 has a card slot 342 and a rope fixing hole 343. The card slot 342 is used to install the pre-stretched elastic element 350, and the end of the driving rope 230 is fixed in the rope fixing hole 343.

[0080] Fig.10 Schematic diagram of the steady-state switching mechanism of the bistable actuator 300. The bistable actuator 300 has two stable states: open and closed. When in the open state, it can be switched to the closed state by passive triggering and active driving. Specifically, when the bottom of the flexible member 310 is hit by an external collision, the first trigger block 320 will rotate with the bottom of the flexible member 310, the contact surface will become smaller, and it will not be able to provide enough force to balance the elastic force of the elastic element 350, resulting in structural instability, so that the elastic element 350 is deformed and restored, releasing elastic potential energy, at which time the bottom of the bistable actuator 300 shrinks and folds, presenting a closed steady state; when negative pressure is applied to the inside of the bistable actuator 300 to a certain extent through the air hole 313, the flexible member 310 will also shrink and fold inward, and the first trigger block 320 will also rotate, thereby triggering the steady-state switching.

[0081] When in the closed steady state, when positive pressure is applied to the inside of the bistable actuator 300 to a certain extent through the air hole 313, the flexible member 310 can expand to drive the first trigger block 320 to restore the bottom edge to the posture of abutting each other, and stretch the elastic element 350, thereby returning to the open steady state.

[0082] like Fig.11 , Fig.12 , Fig.13As shown, the trigger 400 includes a connecting frame 410 and a second trigger block 411. The second trigger block 411 is fixedly arranged on the connecting frame 410, and the second trigger block 411 is located below the first trigger block 320. A slider 412 is provided on the connecting frame 410, and the base and the connecting frame are slidably connected through the guide rail 130 and the slider 412.

[0083] When the second trigger block 411 contacts an object, the connecting frame 410 may move upward along the guide rail 130 and collide with the bottom of the bistable actuator 300 to cause a state transition.

[0084] The adsorption mechanism 420 has a suction cup air inlet 421 and a suction cup air outlet 422, and is mounted on the second trigger block 411. By applying negative pressure or positive pressure to the suction cup air inlet 421, the adsorption or desorption of the contact object at the suction cup air outlet 422 can be achieved, and the suction cup air inlet 421 is connected to an air pump.

[0085] Since the multi-mode bistable flexible gripper for water and air amphibious drones provided in the embodiment has a bistable characteristic and is combined with two operating mechanisms, namely grasping and sucking, it has multi-mode operation capabilities and is suitable for grasping more types of objects and more complex environments. Some working modes are listed below to further illustrate the principle of the multi-mode bistable flexible gripper for water and air amphibious drones provided in the embodiment.

[0086] Working Mode 1:

[0087] Passive triggering of fast grabbing mode, such as Fig.14 As shown. When the trigger 400 is subjected to external collision, such as when the suction cup contacts natural structures such as branches during the descent of the drone, the trigger 400 moves upward and collides with the bottom of the bistable actuator 300, causing the bistable actuator 300 to jump from an open state to a closed state. The deformation generated in this process can drive the drive rope 230 to tighten, driving the rope-driven soft fingers 200 to bend inward to complete the grasping action. This function is suitable for helping drones to land and perch quickly. In addition, by adjusting the air pressure in the flexible member 310, the trigger force required for the bistable state switching can be changed to adapt to different environments or to grasp different objects. For example, in a high wind and wave environment, positive pressure can be applied to increase the gripper trigger force to prevent the gripper from accidentally touching the gripper under interference from the external environment; when grasping a moving object with small momentum, a small negative pressure is applied to reduce the gripper trigger force, which can reduce the energy input required for the gripper to grasp, thereby adapting to the dynamic grasping of small momentum objects.

[0088] Working Mode 2:

[0089] Actively trigger the fast grab mode, such as Fig.15When a certain negative pressure is applied to the flexible member 310 through the air hole 313, the bistable actuator 300 can be actively driven to jump from the open state to the closed state, and the driving rope 230 drives the rope-driven soft finger 200 to perform the grasping action. This mode does not rely on the collision of external objects and is suitable for the drone to actively and quickly grasp objects.

[0090] Working Mode 3:

[0091] Active triggering of the soft grip mode, such as Fig.16 As shown. Negative pressure is applied in advance to put the bistable actuator 300 in a closed stable state, and the gripper is in a grasping closed state. A small positive pressure is applied to the flexible member 310 through the air hole 313, so that the bottom of the bistable actuator 300 can be slightly stretched, thereby loosening part of the driving rope 230 to partially open the rope-driven soft finger 200, allowing the object to enter the middle of the finger. Then the applied positive pressure is slowly reduced, so that the rope-driven soft finger 200 slowly sticks to the grasped object, thereby completing the gentle grasping. This mode is suitable for helping drones to perform non-destructive sampling tasks on fragile organisms.

[0092] Working Mode 4:

[0093] Absorption mode, such as Fig.17 As shown. The suction mechanism 420 is driven to suck the object only through the suction cup air inlet 421. This mode is suitable for grabbing flat objects and objects that are too small or too large relative to the gripper.

[0094] Working Mode 5:

[0095] Grab and suck mixed mode, such as Fig.18 At the same time, negative pressure is applied to the flexible member 310 and the suction mechanism 420 through the air hole 313 and the suction cup air inlet 421, respectively, so that the gripper performs the grasping operation and the suction operation at the same time. This mode can improve the grasping stability of the gripper. For example, when the drone lands on a smooth surface, the simple grasping mode cannot provide enough friction to ensure the stability of the drone. The grasping and suction mixed mode can additionally increase the suction force of the suction cup and increase the grasping stability.

[0096] Although the embodiments of the present application have been shown and described above, the scope of protection of the present invention is not limited thereto, and any changes or substitutions that are not conceivable through creative work should be included in the scope of protection of the present invention; unless explicitly stated, any elements, actions or instructions used in this document should not be interpreted as critical or necessary.

Claims

1. A multi-mode bistable flexible gripper for an amphibious drone, characterized in that: include: Pedestal; at least two rope-driven soft fingers rotatably disposed on the base; at least one bistable actuating mechanism fixedly disposed on the base; at least one trigger; Wherein, the at least one bistable actuating mechanism is used to automatically actuate the at least two rope-driven soft fingers to grasp and release an object, and / or The at least one bistable actuating mechanism is used to be triggered by the at least one trigger, so that the at least one bistable actuating mechanism actuates the at least two rope-driven soft fingers to grasp and release an object, and / or The at least one bistable actuating mechanism is provided with a partial triggering force by the at least one trigger when the at least one bistable actuating mechanism actuates the at least two rope-driven soft fingers to grasp and release an object; Wherein, at least one adsorption mechanism is arranged on the trigger for adsorbing objects.

2. The multi-mode bistable flexible gripper for an amphibious aerial drone according to claim 1 is characterized in that: The bistable actuator has an open stable state and a closed stable state, and the bistable actuating mechanism comprises: A flexible member having a driving air cavity, an air hole and at least two first trigger blocks; and At least two fixers are arranged at the bottom of the flexible member; Wherein, the driving air cavity is communicated with the air hole; The at least two first trigger blocks are located at the bottom of the flexible member; The at least two rope-driven soft fingers have driving ropes, and the driving ropes of the at least two rope-driven soft fingers are connected one by one with the at least two fixers; When the driving air cavity is adjusted to a negative pressure and causes the flexible member to contract, the at least two first trigger blocks guide the contraction of the flexible member; When the driving air cavity is adjusted to a negative pressure and causes the flexible member to contract, the at least two fixers are configured to gradually move closer together as the flexible member contracts, causing the rope-driven soft fingers to perform a grasping action.

3. The multi-mode bistable flexible gripper for an amphibious drone according to claim 2 is characterized in that: The bistable actuating mechanism further comprises: at least one elastic element stretched and fixedly arranged on the at least two fixtures; The first trigger block has a contact surface, and the contact surfaces of adjacent first trigger blocks contact each other to balance the elastic force of the at least one elastic element; When the adjacent first trigger block guides the contraction of the flexible member, the at least one elastic element releases the stored elastic potential energy to provide kinetic energy for the movement of the trigger.

4. The multi-mode bistable flexible gripper for an amphibious drone according to claim 3 is characterized in that: A connecting shaft is provided at the bottom of the flexible member, and the connecting shaft is used to provide support for the bottom of the flexible member; Wherein, the fixer is fixedly connected to the connecting shaft, and the connecting shaft is located on the side of the first trigger block.

5. The multi-mode bistable flexible gripper for an amphibious drone according to claim 2, characterized in that: The trigger includes: A connecting frame configured to be slidably connected to the base; as well as A second trigger block is fixedly disposed on the connecting frame; Wherein, the second trigger block is located below the first trigger block, and the second trigger is used to collide with the bottom of the flexible member to change the bistable actuator from an open stable state to a closed stable state; The adsorption mechanism is fixedly arranged on the connecting frame and / or the connecting frame.

6. The multi-mode bistable flexible gripper for an amphibious drone according to claim 3 is characterized in that: The first trigger block is in the shape of a triangular prism, and the bottom surface of the first trigger block serves as the abutting surface; There is an even number of the first trigger blocks, every two of the first trigger blocks form a group, and the two first trigger blocks in each group are symmetrically arranged; The adjacent first trigger blocks are arranged on the inner bottom surface of the driving air cavity with their bottom surfaces abutting against each other; One side surface of the first trigger block is fixedly connected to the inner bottom surface of the driving air cavity.

7. The multi-mode bistable flexible gripper for an amphibious drone according to claim 2, characterized in that: The rope-driven soft finger comprises: A finger body having a mounting groove; An exoskeleton inserted into the mounting slot; and A fingertip, fixedly disposed at the end of the finger body; The outer frame is provided with a perforation, the outer frame and the mounting groove are both provided with a plurality of holes, the plurality of mounting grooves are distributed at equal intervals, and the outer frame is fixedly connected to the finger body; The driving rope passes through the through hole; One end of the driving rope is fixed on the outer frame adjacent to the fingertip, and the other end of the driving rope is fixed on the fixer.

8. The multi-mode bistable flexible gripper for an amphibious drone according to claim 5, characterized in that: The base is provided with a guide rail, the connecting frame is provided with a slider, and the base and the connecting frame are slidably connected via the guide rail and the slider.

9. The multi-mode bistable flexible gripper for an amphibious aerial drone according to claim 2, characterized in that: The top of the flexible member is fixedly connected to the base.

10. The multi-mode bistable flexible gripper for an amphibious drone according to claim 6, characterized in that: The first trigger block is an elastic body.

Images