Electro-hydrodynamic driven integrated unmanned aerial vehicle flexible actuator system

Abstract

The application discloses a kind of based on electrohydrodynamics drive variable integration unmanned plane flexible actuator system.System includes unmanned plane, pedestal, is equipped with dielectric liquid liquid storage cylinder and several drive variable integration flexible actuators, pedestal is horizontally installed in the center just below unmanned plane, liquid storage cylinder is installed on pedestal, each drive variable integration flexible actuator is vertically arranged in the circumferential direction of pedestal and is uniformly spaced below pedestal, each drive variable integration flexible actuator is electrically connected unmanned plane and is communicated liquid storage cylinder, by double-side electro-hydraulic combined drive each drive variable integration flexible actuator generates strain difference to realize bidirectional bending, to realize grabbing target object or buffering unmanned plane landing in turn.The application system structure is compact, drive response is fast, and has grabbing and landing buffering function, significantly improves the grabbing capacity and environmental adaptability of unmanned plane.

Description

TECHNICAL FIELD

[0001] The present application relates to a UAV flexible actuator system, and relates to the technical field of UAV operation, in particular to a current-driven integrated UAV flexible actuator system based on electrohydrodynamics. BACKGROUND

[0002] The UAV equipment actuator can expand the operation ability of the UAV, accelerate the application of the UAV in industrial inspection, logistics transportation and other industrial scenes, however, the existing on-board actuator mainly has some problems. The rigid actuator has large mass and volume, significantly increases the load of the UAV and reduces the endurance, and puts forward higher requirements for the operation accuracy of the UAV. Although the flexible actuator is light and has good compliance, most of them need to be driven by a gas pump, which increases the system mass, reduces the endurance and load capacity of the UAV. The actuator driven by liquid-gas phase change realizes the lightweight of the driving source, but has slow response and low switching frequency, and it is difficult to realize fast grabbing and frequent action switching. In addition, most of the current on-board actuators have single function, and lack function switching in task scenes. Therefore, there is an urgent need for a multifunctional, rapid-response and compact UAV on-board actuator. SUMMARY

[0003] In order to solve the problems in the background art, the present application provides a current-driven integrated UAV flexible actuator system based on electrohydrodynamics. The present application realizes the rapid driving of the actuator by electrohydrodynamics, and integrates the driving circuit into the flexible actuator, which is compact in structure. In addition, the flexible actuator can bend inward or outward to realize function switching; bending inward is used for grabbing target objects, and bending outward is used for buffering landing.

[0004] The technical scheme adopted by the present application is:

[0005] The current-driven integrated UAV flexible actuator system based on electrohydrodynamics comprises a UAV, a base, a liquid storage cylinder containing dielectric liquid, and a plurality of current-driven integrated flexible actuators. The base is horizontally installed directly below the center of the UAV, the liquid storage cylinder is installed on the base, and each current-driven integrated flexible actuator is vertically arranged below the base along the circumference of the base. Each current-driven integrated flexible actuator is electrically connected to the UAV and communicates with the liquid storage cylinder. Each current-driven integrated flexible actuator is driven by double-sided electro-hydraulic drive to generate a strain difference to realize bidirectional bending, and then to grab target objects or buffer UAV landing.

[0006] Each of the strain-driving integrated flexible actuators comprises a first elastomer layer, a first interdigital electrode layer, a second elastomer layer, a strain limiting layer, a third elastomer layer, a second interdigital electrode layer and a fourth elastomer layer arranged in sequence by adhesive lamination, a groove is formed on the side of the first elastomer layer close to the first interdigital electrode layer as a first liquid cavity, a groove is formed on the side of the fourth elastomer layer close to the second interdigital electrode layer as a second liquid cavity, liquid inlets are arranged on the root end face of the elastomer layer close to the base and respectively communicate with the liquid cavities, and the liquid cavities are connected to the liquid storage cylinder through the liquid inlets and pipelines.

[0007] The interdigital electrode layers are respectively printed on the elastomer layers and located in the liquid cavities, and the length and width dimensions of the interdigital electrode layers are less than or equal to the length and width dimensions.

[0008] The liquid cavities are filled with dielectric liquid through the liquid storage cylinder, the interdigital electrode layers and the dielectric liquid are in direct contact, when the first interdigital electrode layer is powered, the pressure in the first liquid cavity rises to make the strain-driving integrated flexible actuator bend inward to realize the grasping of the target object, and when the second interdigital electrode layer is powered, the pressure in the second liquid cavity rises to make the strain-driving integrated flexible actuator bend outward to realize the buffering or landing protection of the unmanned aerial vehicle.

[0009] The top surface of the liquid storage cylinder is provided with a liquid injection port, the liquid storage cylinder is installed on the top surface of the base after being filled with dielectric liquid through the liquid injection port, and the circumferential bottom of the liquid storage cylinder is uniformly and spacedly provided with a plurality of pairs of liquid outlets, each pair of liquid outlets is located above the root end of a respective one of the strain-driving integrated flexible actuators and respectively communicates with a respective one of the liquid inlets in the strain-driving integrated flexible actuators through a pipeline.

[0010] The root end of the strain-driving integrated flexible actuator is installed on the bottom surface of the base through a clamping device, the clamping device comprises a first clamping sheet and a second clamping sheet, the top surface of the second clamping sheet is installed on the bottom surface of the base, and the first clamping sheet is installed on the side surface of the second clamping sheet and clamps the root end of the strain-driving integrated flexible actuator between the first clamping sheet and the second clamping sheet.

[0011] The base is installed on the center directly below the unmanned aerial vehicle through a plurality of connecting columns, and the liquid storage cylinder is installed between the center of the bottom surface of the base and the fuselage of the unmanned aerial vehicle.

[0012] The control method of the strain-driving integrated unmanned aerial vehicle flexible actuator system based on electrohydrodynamics of the application comprises:

[0013] The liquid cavity of the drive-variant integrated flexible actuator is filled with dielectric liquid and is in an initial state of unexpanded deformation, the drive-variant integrated unmanned aerial vehicle flexible actuator system inputs high-voltage electricity higher than a preset voltage to each first interdigital electrode layer or second interdigital electrode layer through an unmanned aerial vehicle, the dielectric liquid in the liquid storage cylinder enters the liquid cavity along the pipeline through electrohydrodynamics, the pressure in the liquid cavity is increased, a strain difference is generated between the elastomer layer (511, 513, 521, 523) and the strain limiting layer, thereby causing controllable directional bending deformation and function switching of the drive-variant integrated flexible actuator, so as to realize the grabbing function of the target object by bending inward, and realize the buffer or landing protection function of the unmanned aerial vehicle by bending outward.

[0014] When the drive-variant integrated unmanned aerial vehicle flexible actuator system realizes the grabbing function of the target object, the unmanned aerial vehicle is controlled to fly above the target object, the unmanned aerial vehicle is powered to each first interdigital electrode layer of the drive-variant integrated flexible actuator, so that the dielectric liquid flows from the liquid storage cylinder to each first liquid cavity under the action of the electric field force, each first liquid cavity expands to make each drive-variant integrated flexible actuator bend inward, and then the target object is grabbed; when the unmanned aerial vehicle releases the target object, each first interdigital electrode layer is powered off, each drive-variant integrated flexible actuator returns to the initial state, the dielectric liquid flows back from the first liquid cavity to the liquid storage cylinder, and the target object is released by falling.

[0015] When the drive-variant integrated unmanned aerial vehicle flexible actuator system realizes the buffer or landing protection function of the unmanned aerial vehicle, the unmanned aerial vehicle is controlled to fly above the ground, the unmanned aerial vehicle is powered to each second interdigital electrode layer of the drive-variant integrated flexible actuator, so that the dielectric liquid flows from the liquid storage cylinder to each second liquid cavity under the action of the electric field force, each second liquid cavity expands to make each drive-variant integrated flexible actuator bend outward, the unmanned aerial vehicle buffers landing, and the second interdigital electrode layer is powered off after landing.

[0016] The beneficial effects of the present application are:

[0017] 1. Compared with air pump driving, liquid-gas phase change driving or other electric driving forms, the electrohydrodynamic driving adopted by the present application has fast response speed, light quality and good flexibility.

[0018] 2. The present application integrates driving and deformation into one, which on the one hand shortens the fluid transmission path to further improve the driving response speed of the actuator, and on the other hand eliminates the space occupation of the driving source, so that the overall structure is compact and convenient for integration with the unmanned aerial vehicle.

[0019] 3. The independent electric driving of the inner and outer mirror image liquid cavities and the interdigital electrodes of the present application enables the actuator to realize inward bending (grabbing function) or outward bending (buffer landing function) through selective power supply, realizes two types of complementary functions in a single unit, improves the task diversity and space utilization of the system, and significantly improves the grabbing ability and environmental adaptability of the unmanned aerial vehicle.

[0020] 4、The flexible planar interdigital electrode of the present application is printed on the elastomer layer bonded with the strain limiting layer, so that the deformation of the electrode is small when the actuator is bent, and the driving stability is high.

[0021] 5、The flexible actuator of the present application has compliance and passive adaptation ability, so that the unmanned aerial vehicle realizes grabbing under low positioning accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the outward bending of the flexible actuator of the unmanned aerial vehicle of the present application;

[0023] Figure 2 It is a schematic diagram of the three-dimensional structure of the inward bending of the flexible actuator of the unmanned aerial vehicle of the present application to grab objects;

[0024] Figure 3 It is a schematic diagram of the three-dimensional structure of the flexible actuator of the unmanned aerial vehicle of the present application in the undriven state;

[0025] Figure 4 It is an exploded schematic diagram of the drive-strain integrated flexible actuator of the present application;

[0026] Figure 5 It is a cross-sectional schematic diagram of the drive-strain integrated flexible actuator of the present application;

[0027] Figure 6 It is a schematic diagram of the three-dimensional structure of the base of the present application;

[0028] Figure 7 It is a top view schematic diagram of the liquid storage cylinder of the present application;

[0029] Figure 8 It is a schematic diagram of the three-dimensional structure of the liquid storage cylinder of the present application;

[0030] Figure 9 It is a schematic diagram of the three-dimensional structure of the clamping device of the present application;

[0031] In the figure: 10, unmanned aerial vehicle, 20, base, 21, first mounting hole, 22, second mounting hole, 23, third mounting hole, 30, liquid storage cylinder, 31, fourth mounting hole, 32, liquid injection port, 33, liquid outlet, 40, pipeline, 50, drive-strain integrated flexible actuator, 510, first liquid cavity, 511, first elastomer layer, 512, first interdigital electrode layer, 513, second elastomer layer, 54, strain limiting layer, 520, second liquid cavity, 521, fourth elastomer layer, 522, second interdigital electrode layer, 523, third elastomer layer, 55, liquid inlet, 60, clamping device, 61, first connecting hole, 62, first clamping piece, 63, second clamping piece, 64, fifth mounting hole, 65, second connecting hole. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar notations represent the same or similar elements or elements with the same or similar functions throughout. The technical scheme described below by reference to the drawings is exemplary and is intended to explain the present application and cannot be understood as limiting the present application. Based on the technical scheme in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0033] In the description of the present application, it should be noted that unless explicitly specified and limited, the terms "mounting", "connection" and "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] As shown in Figure 1 , Figure 2 and Figure 3 , the electrohydrodynamic-based drive and integration flexible actuator system of the unmanned aerial vehicle of the present application comprises an unmanned aerial vehicle 10, a base 20, a liquid storage cylinder 30 filled with dielectric liquid, and three or more drive and integration flexible actuators 50. The unmanned aerial vehicle 10 can specifically adopt a four-rotor unmanned aerial vehicle with a wheelbase of 450 mm, and four circumferentially distributed drive and integration flexible actuators 50 are integrated, which have the functions of landing gear and flexible gripper. The unmanned aerial vehicle 10 is equipped with a high-voltage DC-DC booster module, the input voltage is 11.1V - 14.8V, and the output high-voltage adjustable range is 4 kV - 10 kV. The base 20 is horizontally mounted directly below the center of the unmanned aerial vehicle 10, the liquid storage cylinder 30 is mounted on the base 20, and each drive and integration flexible actuator 50 is vertically arranged below the base 20 in uniform intervals along the circumference of the base 20. Each drive and integration flexible actuator 50 is electrically connected to the unmanned aerial vehicle 10 and communicates with the liquid storage cylinder 30. The dielectric liquid in the liquid storage cylinder 30 is a dielectric liquid with high electronegative molecules, such as 3M fluorinated liquid, model Novec 7200. The base 20 can be circular or regular polygonal to mount three or more drive and integration flexible actuators 50, and the number of liquid outlets 33 of the liquid storage cylinder 30 is equal to the number of drive and integration flexible actuators 50. Each drive and integration flexible actuator 50 is driven by double-sided electro-hydraulic drive to generate strain difference to realize bidirectional bending, and then to realize grasping target objects or buffering the landing of the unmanned aerial vehicle 10.

[0035] As shown in Figure 4 andFigure 5 As shown, each drive-integrated flexible actuator 50 comprises a first elastomer layer 511, a first interdigital electrode layer 512, a second elastomer layer 513, a strain limiting layer 54, a third elastomer layer 523, a second interdigital electrode layer 522 and a fourth elastomer layer 521 arranged in a glueing stack, and the drive-integrated flexible actuator 50 is composed of multiple layers of materials glued together along the thickness direction. In a specific implementation, the effective length of a single drive-integrated flexible actuator 50 is 150 mm, the width is 40 mm, and the total thickness is 8 mm in the uncharged state. The elastomer layers 511, 513, 521 and 523 are made of silicone rubber, and the strain limiting layer 54 can be made of non-woven fabric. The three layers of the first elastomer layer 511, the first interdigital electrode layer 512 and the second elastomer layer 513 are mirror images of the three layers of the third elastomer layer 523, the second interdigital electrode layer 522 and the fourth elastomer layer 521 with the strain limiting layer 54 as the symmetry plane. The first elastomer layer 511 has a groove on one side close to the first interdigital electrode layer 512 as a first liquid cavity 510, and the fourth elastomer layer 521 has a groove on one side close to the second interdigital electrode layer 522 as a second liquid cavity 520. The elastomer layers 511 and 521 are provided with liquid inlets 55 on the root end surface close to the base 20 and are respectively connected to the liquid cavities 510 and 520. The liquid cavities 510 and 520 are connected to the liquid storage cylinder 30 through the liquid inlet 55 and the pipeline 40. The other side of the first elastomer layer 511 away from the first interdigital electrode layer 512 serves as the back of the drive-integrated flexible actuator 50, and the other side of the fourth elastomer layer 521 away from the second interdigital electrode layer 522 serves as the palm of the drive-integrated flexible actuator 50. The positive and negative electrodes of the interdigital electrode layers 512 and 522 are respectively electrically connected to the unmanned aerial vehicle 10 to drive independently.

[0036] The interdigital electrode layers 512 and 522 of the drive-integrated flexible actuator 50 are screen printed on the elastomer layers 513 and 523 respectively and located in the liquid cavities 510 and 520 respectively. The interdigital electrodes 512 and 522 are flexible electrode materials formed by metal paste printing or flexible conductive composite layer, which can use carbon-based conductive ink to ensure the conductivity and mechanical reliability of the interdigital electrodes 512 and 522 when the elastomer layers 511, 513, 523 and 521 deform. The interdigital width is 2 mm, the narrow spacing between electrodes is 1 mm, and the wide spacing is 2 mm. The length and width dimensions of the interdigital electrode layers 512 and 522 are less than or equal to the length and width dimensions. The upper side of the positive electrode horizontal electrode of the interdigital electrode 512 is close to the lower side of the negative electrode horizontal electrode, thereby ensuring that the dielectric liquid is pushed from the inlet to the deep part of the liquid cavity when electrified to achieve the expected deformation effect.

[0037] The base 20 is installed at the center directly below the unmanned aerial vehicle 10 through several connecting columns, and the liquid storage cylinder 30 is installed between the center of the bottom surface of the base 20 and the unmanned aerial vehicle 10. As shown in FIG. 1, Figure 6As shown, the four corners of the base 20 are provided with first mounting holes 21 connected with the unmanned aerial vehicle 10, the four sides of the base 20 are provided with second mounting holes 22 for fixing the clamping device 60, and the center of the base 20 is provided with a third mounting hole 23 for fixing the liquid storage cylinder 30, so as to ensure the overall fixation and installation positioning of the structure.

[0038] The liquid chambers 510 and 520 are filled with dielectric liquid through the liquid storage cylinder 30, and the interdigital electrode layers 512 and 522 are in direct contact with the dielectric liquid; when the first interdigital electrode layer 512 is powered, the pressure in the first liquid chamber 510 rises to make the metamorphic integrated flexible actuator 50 bend inward to achieve the grasping of the target object; when the second interdigital electrode layer 522 is powered, the pressure in the second liquid chamber 520 rises to make the metamorphic integrated flexible actuator 50 bend outward to expand to achieve the buffering or landing protection of the unmanned aerial vehicle 10. Figure 7 and Figure 8 As shown, the top surface of the liquid storage cylinder 30 is provided with a liquid injection port 32, and the liquid storage cylinder 30 is installed on the top surface of the base 20 after being filled with dielectric liquid through the liquid injection port 32; the circumferential bottom of the liquid storage cylinder 30 is uniformly and spacedly provided with a plurality of pairs of liquid outlet ports 33, so as to ensure that the dielectric liquid in the liquid storage cylinder 30 can be effectively and sufficiently delivered to the metamorphic integrated flexible actuator 50 during electric driving; each pair of liquid outlet ports 33 is located above the root end of a respective one of the metamorphic integrated flexible actuators 50 and is connected with a respective one of the liquid inlet ports 55 in the metamorphic integrated flexible actuator 50 through a pipeline 40. The side of the liquid storage cylinder 30 is provided with a fourth mounting hole 31 connected with the base 20.

[0039] The root end of the metamorphic integrated flexible actuator 50 is installed on the bottom surface of the base 20 through the clamping device 60, the clamping device 60 includes a first clamping sheet 62 and a second clamping sheet 63, the top surface of the second clamping sheet 63 is installed on the bottom surface of the base 20, and the first clamping sheet 62 is installed on the side surface of the second clamping sheet 63 and clamps the root end of the metamorphic integrated flexible actuator 50 between the first clamping sheet 62 and the second clamping sheet 63. Figure 9 As shown, the first clamping sheet 62 is a few-shaped, the two sides of the first clamping sheet 62 are symmetrically provided with first connecting holes 61, the second clamping sheet 63 is L-shaped, one section of the second clamping sheet 63 is provided with a fifth mounting hole 64 connected with the base 20, and the other section of the second clamping sheet 63 is provided with a second connecting hole 65 connected with the first connecting hole 61, and the root end of the metamorphic integrated flexible actuator 50 is clamped between the middle groove of the first clamping sheet 62 and the other section of the second clamping sheet 63.

[0040] The control method of the current-driven metamorphic integrated unmanned aerial vehicle flexible actuator system is as follows:

[0041] The liquid chambers 510, 520 of the drive-integrated flexible actuator 50 are filled with dielectric liquid and are in an initial state of unexpanded deformation. The drive-integrated unmanned aerial vehicle flexible actuator system inputs high-voltage electricity higher than a preset voltage 2kV to each of the first interdigital electrode layer 512 or the second interdigital electrode layer 522 through the unmanned aerial vehicle 10, drives the dielectric liquid in the liquid storage cylinder 30 to enter the liquid chambers 510, 520 through the pipeline 40 by electrohydrodynamics, increases the pressure in the liquid chambers 510, 520, generates a strain difference between the elastomer layers 511, 513, 521, 523 and the strain limiting layer 54, causes controllable directional bending deformation and function switching of the drive-integrated flexible actuator 50, and bends inward to achieve the grabbing function of the target object, or bends outward to expand to achieve the buffer or landing protection function of the unmanned aerial vehicle 10.

[0042] When the drive-integrated unmanned aerial vehicle flexible actuator system realizes the grabbing function of the target object, the unmanned aerial vehicle 10 is controlled to fly above the target object, the unmanned aerial vehicle 10 is powered to each of the first interdigital electrode layers 512 of the drive-integrated flexible actuators 50, the dielectric liquid flows from the liquid storage cylinder 30 to each of the first liquid chambers 510 under the action of the electric field force, each of the first liquid chambers 510 expands to cause each of the drive-integrated flexible actuators 50 to bend inward, and then grab the target object; when the unmanned aerial vehicle 10 releases the target object, each of the first interdigital electrode layers 512 is powered off, each of the drive-integrated flexible actuators 50 returns to the initial state, the dielectric liquid flows back from the first liquid chambers 510 to the liquid storage cylinder 30, and the target object is dropped and released.

[0043] When the drive-integrated unmanned aerial vehicle flexible actuator system realizes the buffer or landing protection function of the unmanned aerial vehicle 10, the unmanned aerial vehicle 10 is controlled to fly above the ground, the unmanned aerial vehicle 10 is powered to each of the second interdigital electrode layers 522 of the drive-integrated flexible actuators 50, the dielectric liquid flows from the liquid storage cylinder 30 to each of the second liquid chambers 520 under the action of the electric field force, each of the second liquid chambers 520 expands to cause each of the drive-integrated flexible actuators 50 to bend outward and expand, the unmanned aerial vehicle 10 buffers and lands, and the second interdigital electrode layers 522 are powered off after landing.

[0044] The electrohydrodynamic driving principle is that when high-voltage electricity is applied to the interdigital electrode layers 512, 522, electrons can jump from the negative electrode surface to the dielectric liquid to generate negatively charged particles or polarization states in the dielectric liquid, which flow from the liquid inlet 55 to the deep part of the liquid chamber 510, 520 along the designed fluid channel under the driving of the electric field force, realizes electrically controlled flow and pressure change of the liquid chamber, and the pressure of the liquid chamber increases with the increase of the high-voltage electricity. After power-off, the excess liquid in the liquid chambers 510, 520 is squeezed out by the elastomer layers 511, 513, 523, 521, and the drive-integrated flexible actuator 50 returns to the original state.

[0045] In specific implementation, as Figure 1As shown, the experimental scene of the present application is set as the landing of the unmanned aerial vehicle 10 on a hard cement ground: when the unmanned aerial vehicle 10 descends to a height of about 0.2 m from the ground, a direct current high voltage of 6 kV is applied to the inner second interdigital electrode layer 522 of the four drive-integrated flexible actuators 50, and under the action of the electrohydrodynamic effect, the dielectric liquid flows from the liquid storage cylinder 30 to the second liquid cavity 520 located inside the four drive-integrated flexible actuators 50, causing a strain difference between the fourth elastic body layer 521 and the strain limiting layer 54, and the four drive-integrated flexible actuators 50 bend outward by 90° synchronously, so that the support span of the bottom of the unmanned aerial vehicle 10 expands from the initial 150 mm to 300 mm, significantly increasing the chassis stability during landing and preventing rollover; at the moment of the unmanned aerial vehicle 10 touching the ground, the four drive-integrated flexible actuators 50 and the second liquid cavity 520 inside them act as dampers to absorb impact energy, effectively protecting the core components of the fuselage; after the unmanned aerial vehicle 10 lands stably, the power supply of the second interdigital electrode layer 522 is cut off, and the landing of the unmanned aerial vehicle 10 on the hard cement ground is completed.

[0046] In specific implementation, as shown in the accompanying drawings, Figure 2 As shown, the experimental scene of the present application is set as grabbing a spherical object with a diameter of 100 mm and a weight of 150 g placed on the ground: the unmanned aerial vehicle flight control issues a command to apply a direct current high voltage of 8 kV to the outer first interdigital electrode layer 512 of the four drive-integrated flexible actuators 50 through the high voltage module, and under the action of the electrohydrodynamic effect, the dielectric liquid in the liquid storage cylinder 30 is quickly injected into the outer first liquid cavity 510 within 500 ms, causing a strain difference between the first elastic body layer 511 and the strain limiting layer 54, and the four drive-integrated flexible actuators 50 bend inward synchronously by an angle of up to 120° (when empty). It is sufficient to grab the spherical object. After the unmanned aerial vehicle 10 carries the object to the designated position, the power supply of the first interdigital electrode layer 512 is cut off, the electrohydrodynamic effect disappears, the first elastic body layer 511 relies on its own elastic potential energy to retract, and the dielectric liquid is squeezed back into the liquid storage cylinder 30, and the four drive-integrated flexible actuators 50 recover to the vertical initial state within 2 s, and the spherical object naturally falls and releases under the action of gravity.

[0047] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An electrohydrodynamic-based actuation and integration unmanned aerial vehicle flexible actuator system, characterized by: The unmanned aerial vehicle (10), the base (20), the liquid storage cylinder (30) filled with dielectric liquid and a plurality of drive-strain integrated flexible actuators (50) are included, the base (20) is horizontally installed at the center of the unmanned aerial vehicle (10) directly below, the liquid storage cylinder (30) is installed on the base (20), each drive-strain integrated flexible actuator (50) is vertically arranged below the base (20) along the circumference of the base (20) and is uniformly spaced, each drive-strain integrated flexible actuator (50) is electrically connected to the unmanned aerial vehicle (10) and is communicated with the liquid storage cylinder (30), each drive-strain integrated flexible actuator (50) is driven by double-side electro-hydraulic combination to generate strain difference to realize bidirectional bending, and then to realize the grasping of target objects or the buffering of the landing of the unmanned aerial vehicle (10).

2. The electrohydrodynamic-based actuation-integrated unmanned aerial vehicle flexible effector system of claim 1, wherein: Each drive-strain integrated flexible actuator (50) includes a first elastomer layer (511), a first interdigital electrode layer (512), a second elastomer layer (513), a strain limiting layer (54), a third elastomer layer (523), a second interdigital electrode layer (522) and a fourth elastomer layer (521) arranged in sequence, a groove is formed on the side of the first elastomer layer (511) close to the first interdigital electrode layer (512) as a first liquid cavity (510), a groove is formed on the side of the fourth elastomer layer (521) close to the second interdigital electrode layer (522) as a second liquid cavity (520), the liquid inlet (55) is arranged on the root end surface of the elastomer layer (511, 521) close to the base (20) and is communicated with the liquid cavity (510, 520) respectively, the liquid cavity (510, 520) is connected to the liquid storage cylinder (30) through the liquid inlet (55) and the pipeline (40); the other side of the first elastomer layer (511) away from the first interdigital electrode layer (512) is the back of the finger of the drive-strain integrated flexible actuator (50), the other side of the fourth elastomer layer (521) away from the second interdigital electrode layer (522) is the palm of the finger of the drive-strain integrated flexible actuator (50); the interdigital electrode layers (512, 522) are electrically connected to the unmanned aerial vehicle (10) to be independently driven.

3. The electrohydrodynamic-based actuation-integrated unmanned aerial vehicle flexible actuator system of claim 2, wherein: The interdigital electrode layers (512, 522) are printed on the elastomer layers (513, 523) and are located in the liquid cavities (510, 520) respectively.

4. The electrohydrodynamic-based actuation-integrated unmanned aerial vehicle flexible actuator system of claim 2, wherein: The liquid cavities (510, 520) are filled with dielectric liquid through the liquid storage cylinder (30), the interdigital electrode layers (512, 522) and the dielectric liquid are in direct contact, when the first interdigital electrode layer (512) is powered, the pressure in the first liquid cavity (510) rises to make the drive-strain integrated flexible actuator (50) bend inward to realize the grasping of target objects, when the second interdigital electrode layer (522) is powered, the pressure in the second liquid cavity (520) rises to make the drive-strain integrated flexible actuator (50) bend outward to realize the buffering or landing protection of the unmanned aerial vehicle (10).

5. The electrohydrodynamic-based actuation-integrated unmanned aerial vehicle flexible actuator system of claim 2, wherein: The top surface of the liquid storage cylinder (30) is provided with a liquid injection port (32), and the liquid storage cylinder (30) is installed on the top surface of the base (20) after being filled with dielectric liquid through the liquid injection port (32). The liquid storage cylinder (30) is uniformly and spacedly provided with a plurality of pairs of liquid outlet ports (33) in the circumferential direction. Each pair of liquid outlet ports (33) is located above the root end of a respective drive-integrated flexible actuator (50) and is respectively connected to a respective liquid inlet port (55) in the drive-integrated flexible actuator (50) through a pipeline (40).

6. The electrohydrodynamic-based actuation-integrated unmanned aerial vehicle flexible actuator system of claim 2, wherein: The root end of the drive-integrated flexible actuator (50) is installed on the bottom surface of the base (20) through a clamping device (60). The clamping device (60) includes a first clamping sheet (62) and a second clamping sheet (63). The top surface of the second clamping sheet (63) is installed on the bottom surface of the base (20). The first clamping sheet (62) is installed on the side surface of the second clamping sheet (63) and clamps the root end of the drive-integrated flexible actuator (50) between the first clamping sheet (62) and the second clamping sheet (63).

7. The electrohydrodynamic-based actuation-integrated unmanned aerial vehicle flexible effector system of claim 1, wherein: The base (20) is installed directly below the center of the unmanned aerial vehicle (10) through a plurality of connecting columns. The liquid storage cylinder (30) is installed between the center of the bottom surface of the body of the unmanned aerial vehicle (10) and the base (20).

8. The control method of the electrohydrodynamic-based integrated morphing unmanned aerial vehicle flexible actuator system according to any one of claims 2-6, characterized in that, Comprise: The liquid chambers (510, 520) of the drive-integrated flexible actuator (50) are filled with dielectric liquid and are in an initial state of non-inflatable deformation. The drive-integrated unmanned aerial vehicle flexible actuator system inputs high-voltage electricity higher than a preset voltage to each first interdigital electrode layer (512) or second interdigital electrode layer (522) through the unmanned aerial vehicle (10), so that the dielectric liquid in the liquid storage cylinder (30) enters the liquid chambers (510, 520) along the pipeline (40) through electrohydrodynamics, the pressure in the liquid chambers (510, 520) is increased, a strain difference is generated between the elastomer layers (511, 513, 521, 523) and the strain limiting layer (54), thereby causing controllable directional bending deformation and function switching of the drive-integrated flexible actuator (50), so as to realize the grabbing function of the target object by bending inward, and realize the buffer or landing protection function of the unmanned aerial vehicle (10) by bending outward.

9. The control method of the electrohydrodynamic-based driven-integrated unmanned aerial vehicle flexible actuator system according to claim 8, wherein: When the drive-integrated unmanned aerial vehicle flexible actuator system realizes the grabbing function of the target object, the unmanned aerial vehicle (10) is controlled to fly above the target object. The unmanned aerial vehicle (10) is powered to each first interdigital electrode layer (512) of each drive-integrated flexible actuator (50), so that the dielectric liquid flows from the liquid storage cylinder (30) to each first liquid chamber (510) under the action of the electric field force. Each first liquid chamber (510) is inflated to cause each drive-integrated flexible actuator (50) to bend inward, thereby grabbing the target object. When the unmanned aerial vehicle (10) releases the target object, each first interdigital electrode layer (512) is powered off, each drive-integrated flexible actuator (50) returns to the initial state, and the dielectric liquid flows back from the first liquid chamber (510) to the liquid storage cylinder (30), and the target object is dropped and released.

10. The control method of the electrohydrodynamic-based propulsion and actuation integrated unmanned aerial vehicle flexible actuator system according to claim 8, wherein: The drive-variable integrated unmanned aerial vehicle flexible actuator system controls the unmanned aerial vehicle (10) to fly above the ground when realizing the buffer or landing protection function of the unmanned aerial vehicle (10), the unmanned aerial vehicle (10) is powered to the second interdigital electrode layer (522) of each drive-variable integrated flexible actuator (50), so that the dielectric liquid flows from the liquid storage cylinder (30) to each second liquid cavity (520) under the action of the electric field force, each second liquid cavity (520) expands to make each drive-variable integrated flexible actuator (50) bend outward and expand, the unmanned aerial vehicle (10) buffers and lands, and the second interdigital electrode layer (522) is powered off after landing.

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