Folding electrostatic hydraulic driver for bionic manta ray pectoral fin, bionic manta ray pectoral fin and parameter design method of bionic manta ray pectoral fin

Abstract

The invention discloses a bionic manta ray pectoral fin-oriented folding type electrostatic hydraulic driver, a bionic manta ray pectoral fin and a parameter design method.The folding type electrostatic hydraulic driver comprises a flexible oil storage sealing bag, dielectric fluid and electrodes, the flexible oil storage sealing bag is divided into an electrode area and a fluid deformation area, and the dielectric fluid is arranged in the electrode area; electrodes are symmetrically attached to the two sides of the electrode area, and the fluid deformation area comprises two deformation cavities; the electrodes are attracted, the dielectric fluid flows from the electrode area to the fluid deformation area, the two deformation cavities expand, the output angle of the driver is increased, and in the bionic manta ray pectoral fin, phase difference is generated by controlling the output angle of the folding type electrostatic hydraulic driver, and propulsive force is formed; and then the driving angle design is optimized by changing parameters such as the content of liquid in the driver and the length of a deformation cavity, and the output force of the folding type electrostatic hydraulic driver is calculated in combination with the input voltage, so that the high efficiency and scientificity of the driver design process are realized, the experiment dependence is reduced, and the design efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of soft bionics, and in particular to a foldable electrostatic hydraulic driver for a bionic manta ray pectoral fin, a bionic manta ray pectoral fin and a parameter design method thereof. Background Art

[0002] Electrostatic hydraulic actuators are a new type of actuator with high ductility, adaptability and low energy consumption. Electrostatic hydraulic actuators usually have a deformable shell (flexible or stretchable), which is covered with a pair of opposing electrodes and filled with liquid dielectric. When voltage is applied to the electrodes, Maxwell stress acts on the shell and the liquid medium, driving the local redistribution of the liquid medium, causing the shape of the shell to change, thereby realizing the conversion of electrical energy into mechanical energy. At present, many researchers at home and abroad have conducted in-depth research on electrostatic hydraulic actuators and applied them to soft robots.

[0003] Patent 2024107687136 discloses an on-water swinging propeller based on electrostatic hydraulic drive, which drives the bionic fish tail to swing left and right through a deformation chamber to simulate the propulsion method of fish; Patent 2024104140122 discloses an underwater bionic flexible actuator based on electrostatic hydraulic drive, which stacks multiple electrostatic hydraulic actuators to achieve the up and down swing of the pectoral fins; Patent 2023113467815 discloses an electrostatic hydraulic actuator using a rigid electrode and its manufacturing method, which uses a rigid electrode to increase the output force, but due to the defects of the film material and the limitations of the structure of the electrostatic drive actuator itself, the angle generated by the rigid electrode is almost the same as the angle generated by the flexible electrode. In the article "Spider-Inspired Electrohydraulic Actuators for Fast Soft-Actuated Joints", researchers obtained the rotation angle and output force of electrostatic actuators under different specifications through a large number of experiments; the existing technology has the following problems: 1. The existing electrostatic hydraulic actuators generally have technical limitations of small driving angles, which makes it unable to meet the requirements of large angle movements in practical applications, thereby limiting its scope of application and function expansion. 2. The current design method of electrostatic hydraulic actuators mainly relies on a large number of experiments and repeated tests, and lacks a scientific parametric design system. This design mode not only consumes a lot of time and resources, but also has the problem of low design efficiency. It is difficult to accurately predict the output performance of the actuator (such as output force and deformation angle), thus affecting the performance optimization and development process of the actuator. Summary of the invention

[0004] Purpose of the invention: The present invention aims to provide a foldable electrostatic hydraulic actuator for bionic manta ray pectoral fins with improved output angle range and a parameter design method thereof; another purpose of the present invention is to provide a bionic manta ray pectoral fin comprising the above-mentioned foldable electrostatic hydraulic actuator.

[0005] Technical solution: The foldable electrostatic hydraulic actuator for bionic manta ray pectoral fins described in the present invention includes a flexible oil storage sealing bag, a dielectric fluid and an electrode. The flexible oil storage sealing bag is divided into an electrode area and a fluid deformation area. Electrodes are symmetrically attached to both sides of the flexible oil storage sealing bag in the electrode area, and the fluid deformation area includes two deformation chambers. When a voltage is applied to the electrode area, the upper and lower electrodes are attracted, the dielectric fluid flows from the electrode area to the fluid deformation area, and the two deformation chambers in the fluid deformation area expand.

[0006] Furthermore, a skirt is left on the periphery of the sealing area of ​​the flexible oil storage sealing bag.

[0007] Furthermore, the electrode is a flexible electrode made of ion-conductive polyacrylamide hydrogel or a rigid electrode made of aluminum foil or copper foil; the area of ​​the electrode is not greater than the area of ​​the electrode region of the flexible oil storage sealing bag.

[0008] Furthermore, the dielectric fluid is vegetable transformer oil with good insulation and low viscosity.

[0009] The bionic manta ray pectoral fin of the present invention comprises a pectoral fin, a side panel, a pectoral fin movable frame, a spring sheet, a skin and the above-mentioned folding electrostatic hydraulic actuator. The front end and the rear end of the pectoral fin are respectively passed through the pectoral fin movable frame and are arranged on the side panel. The spring sheet is installed on both sides of the pectoral fin movable frame. The folding electrostatic hydraulic actuator is symmetrically installed on both sides of the pectoral fin movable frame. The outermost deformation chamber of the folding electrostatic hydraulic actuator is fixed in the mounting groove of the side panel.

[0010] Due to the insufficient rigidity of the soft joints, the skeleton will move downward due to its own gravity. The spring sheet can strengthen the rigidity of the soft joints in the active skeleton of the pectoral fin. The spring sheet has a certain elastic deformation ability. When the folding electrostatic hydraulic actuator moves, the spring sheet and the skeleton will be deformed together. When the folding electrostatic hydraulic actuator is powered off, since a certain elastic potential energy is stored in the spring sheet, the release of this part of the elastic potential energy will help the movement of the folding electrostatic hydraulic actuator on the one hand, and on the other hand, since the dielectric liquid in the fluid deformation area of ​​the previously moving folding electrostatic hydraulic actuator cannot flow back to the electrode part well due to the residual electric field, the stored elastic potential energy makes the liquid in the fluid deformation area flow back to the electrode area, so that the next movement of the folding electrostatic hydraulic actuator is consistent with the state of the previous movement.

[0011] Furthermore, the pectoral fin movable frame includes a limiting plate, a soft joint and a frame, the pectoral fin is mounted on the frame, and the widths of the limiting plate, the frame and the soft joint decrease in sequence.

[0012] Furthermore, the projection of the spring sheet is located within the portion where the pectoral fin is installed, including the limiting plate, the soft joint and the frame.

[0013] Furthermore, the limit plate and the frame have the same hardness, and the hardness of the soft joint is less than the hardness of the limit plate and the frame.

[0014] Furthermore, the mounting groove of the side plate is a variable diameter square hole, and the diameter of the square hole corresponding to the electrode area is smaller than the diameter of the square hole corresponding to the fluid deformation area.

[0015] The parameter design method of the foldable electrostatic hydraulic actuator for bionic manta ray pectoral fins of the present invention comprises the following steps:

[0016] (1) Determine the design parameters of the foldable electrostatic liquid actuator, the length of the deformation chamber in the fluid deformation area L1 = L0, the width of the foldable electrostatic liquid actuator W = W0, the DC voltage value U, the length of the electrode in the electrode area L2 = L0, and the liquid content V injected into the flexible oil storage sealing bag practice ;

[0017] (2) Determine the amplitude θ of the manta ray's pectoral fin o , wave number w and frequency f, establish a simulation model, and calculate the maximum lift F of the pectoral fin under these parameters l ;

[0018] (3) According to the size of the active skeleton of the pectoral fin, the length L1=L0, the width W=W0 of the deformation chamber of the foldable electrostatic hydraulic actuator and the length L2=L0 of the electrode in the electrode area are determined;

[0019] (4) Calculate the content of dielectric liquid when the drive is completely filled

[0020]

[0021] (5) Determine the actual injected dielectric liquid content, V practice =V ideal ×n, n=60%

[0022] (6) Calculate the maximum angle θ generated by the folding electrostatic hydraulic actuator max :

[0023]

[0024] Where A is the cross-sectional area of ​​the folding actuator. y max The maximum height of the folding actuator when it is deformed when powered on;

[0025] (7) Determine the maximum angle θ of the driver max and the optimal fluctuation amplitude θ of manta rayo Relationship:

[0026] When θ max <θ o If yes, go to step (9), otherwise go to step (8);

[0027] (8) Determine the maximum angle θ of the driver max The optimal fluctuation amplitude of manta ray is 1.05θ o Relationship:

[0028] When θ max <1.05×θ o If yes, go to step (11), otherwise go to step (13);

[0029] (9) Determine V practice With V ideal If V practice ≤V ideal , go to step (10), otherwise go to step (12);

[0030] (10) Increasing the dielectric liquid content V in the foldable electrostatic hydraulic actuator zpractice , let n = n + 5%, and return to step (6);

[0031] (11) Calculate the drive output force:

[0032]

[0033] Elastic force of spring leaf

[0034]

[0035] Where ε0 is the dielectric constant of vacuum, ε r is the relative dielectric constant of the dielectric liquid, U is the driving voltage, I is the moment of inertia of the spring sheet, E is the elastic modulus of the spring sheet, and the process goes to step (16);

[0036] (12) Increase the length L1 of the actuator deformation chamber and return to step (4);

[0037] (13) reducing the length L1 of the actuator deformation chamber and returning to step (4);

[0038] (14) Increase the driving voltage value U, U∈[7000,12000], set U=U+1000V, and go to step (8). If U>12000V, go to step (15);

[0039] (15) Increase the length L2 of the driver electrode area and return to step (11);

[0040] (16) Determine F and Fl +2F elastic , if F<F l +2F elastic , then go to step (14), otherwise end.

[0041] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: 1. The present invention sets a plurality of deformation chambers in the fluid deformation area to form a support, thereby increasing the output angle range of the foldable electrostatic hydraulic actuator; 2. The present invention optimizes the drive angle design by changing key parameters such as the liquid content inside the actuator and the length of the deformation chamber, and simultaneously accurately calculates the output force of the foldable electrostatic hydraulic actuator in combination with the input voltage conditions, thereby achieving high efficiency and scientificity in the actuator design process, reducing experimental dependence, and improving design efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the foldable electrostatic fluid actuator in a natural state;

[0043] Figure 2 It is a schematic diagram of the foldable electrostatic fluid actuator in working state;

[0044] Figure 3 Create a schematic for the folded electrostatic fluid actuator;

[0045] Figure 4 This is a schematic diagram of the structure of the bionic pectoral fin;

[0046] Figure 5 It is a schematic diagram of the structure of the active skeleton of the pectoral fin;

[0047] Figure 6 It is a schematic diagram of the pectoral fin movable skeleton in the working state of the foldable electrostatic fluid drive;

[0048] Figure 7 Flowchart for designing a foldable electrostatic fluid actuator based on manta ray related parameters. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with the accompanying drawings.

[0050] The foldable electrostatic hydraulic actuator 1 for bionic manta ray pectoral fins of the present invention comprises a flexible oil storage sealing bag 11 containing 5cs silicone oil, and the flexible oil storage sealing bag comprises two regions, namely an electrode region A and a fluid deformation region B, and a rectangular aluminum foil electrode 12.

[0051] The flexible oil storage sealed bag 11 is formed by folding a rectangular Bopp film with good insulation performance and capable of withstanding large tensile forces twice, and its cross-sectional shape is similar to "Σ". First, a heat sealer is used to heat seal along both sides of the rectangle, and an appropriate amount of 5cs silicone oil is injected, and finally the bag is sealed by a heat sealer. The folded part of the flexible oil storage sealed bag forms a fluid deformation area, and the unfolded part forms an electrode area.

[0052] like Figure 2 As shown, the fluid deformation area B consists of a first deformation chamber B1 and a second deformation chamber B2. The cross-sections of the two chambers are both rectangular, and the second deformation chamber is located directly above the first deformation chamber. One end of the two chambers is interconnected with the electrode area of ​​the flexible oil storage sealing bag to achieve the connection between the electrode area and the fluid deformation area.

[0053] Electrodes 12 are attached to the upper and lower parts of the electrode area. The electrode shape is rectangular. The electrode is mainly made of aluminum foil as a rigid electrode. The length and width of the electrode 12 are slightly smaller than the corresponding dimensions of the electrode area of ​​the flexible oil storage sealing bag.

[0054] The flexible oil storage sealing bag 11 is also designed with a skirt to prevent arcing around it when high voltage is applied. The cross section of the electrode area is rectangular, wherein the length of the electrode area in the flexible oil storage sealing bag 11 is greater than or equal to the length of the fluid deformation area, and the dielectric fluid is a 5cs silicone oil with good insulation performance.

[0055] like Figure 2 As shown, when high voltage is applied to the electrode area, the upper and lower electrodes 12 are quickly attracted to each other, and the 5cs silicone oil flows from the electrode area to the fluid deformation area to generate liquid pressure on the two chambers in the fluid deformation area. When the second deformation chamber expands, the expansion of the first deformation chamber provides support for the second chamber. The angle formed by the expanded second deformation chamber and the horizontal position will be greater than the angle when only one chamber expands.

[0056] like Figure 3As shown, the manufacturing process of the foldable electrostatic hydraulic actuator is mainly made by a plastic sealing machine. First, a rectangular Bopp film 111 with a length of (6L+4) mm and a width of (W+4) mm is obtained by cutting; then, it is folded along the central folding line l1 to obtain a double-layer rectangular film with a length of (3L+4) mm and a width of (W+4) mm; then, it is folded along the outward folding line l2 to obtain a rectangle with four layers of film with a length of L mm and a width of (W+4) mm in the front and two layers of film with a length of (L+2) mm and a width of (W+4) mm in the back; finally, a polyimide film 112 with a length of 2W mm, a width of 2L mm and a thickness of 0.075 mm is sandwiched between the four layers of film in front, and the long side a of the rectangular film is first heat-sealed by a plastic sealing machine, and then an appropriate amount of 5cs silicone oil is injected, and finally it is placed in the plastic sealing machine for sealing.

[0057] like Figure 4 As shown, the bionic manta ray pectoral fin is mainly composed of a foldable electrostatic hydraulic driver 1, a soft silicone pectoral fin 2, a pectoral fin movable skeleton 3, a spring sheet 4, a side panel 5 and a skin 6.

[0058] The soft silicone pectoral fin 2 is a silicone trapezoidal plate, with a row of holes at the upper and lower ends, respectively, which are connected to the holes at the front end of the skeleton 33 of the front and rear pectoral fin movable skeleton 3 of the side plate through screws and nuts.

[0059] like Figure 5 As shown, the pectoral fin movable skeleton 3 is printed by a 3D printer, and its cross section is rectangular. From left to right, it is mainly composed of a limiting plate part 31, a soft joint part 32 and a skeleton part 33. A part of the left end of the soft joint part 32 is embedded in the limiting plate part 31, and a part of the right end is embedded in the skeleton part 33, wherein the width of the skeleton part 33 is smaller than the width of the limiting plate part 31, and the width of the soft joint part 32 is slightly smaller than the width of the skeleton part 33. The hardness of the skeleton part 33 and the limiting plate part 31 is consistent, while the hardness of the soft joint part 32 is smaller than that of the skeleton part 33 and the limiting plate part 31. At the same time, holes are opened at the front end where the skeleton part 33 is connected to the soft joint part 32 and at the end of the limiting plate part 31. The upper and lower sides of the pectoral fin movable skeleton 3 are respectively equipped with spring sheets 4, which are connected by screws and nuts. A row of holes is opened at the front end of the skeleton part 33, which is connected to the holes on the soft silicone pectoral fin 1 by screws and nuts.

[0060] The spring sheet 4 has a rectangular cross section. The front end of the spring sheet has a hole corresponding to the connection between the skeleton part 33 and the soft joint part 32, and the end has a hole corresponding to the end of the limiting plate part 31. The functions of the spring sheet 4 are as follows: due to the insufficient rigidity of the soft joint part 32, the skeleton part 33 will move downward due to its own gravity, thereby strengthening the rigidity of the soft joint part 32 in the pectoral fin movable skeleton 3; the spring sheet 4 has a certain elastic deformation ability, and when the folding electrostatic hydraulic actuator 1 on the upper surface inside the "chimney" moves, the spring sheet 4 and the skeleton part 33 will be deformed together. When the folding electrostatic hydraulic actuator 1 is powered off, since a certain elastic potential energy is stored in the spring sheet 4, the release of this part of the elastic potential energy will help the movement of the folding electrostatic hydraulic actuator 1 on the lower surface inside the "chimney" on the one hand, and on the other hand, since the dielectric liquid in the fluid deformation area of ​​the previously moving folding electrostatic hydraulic actuator 1 cannot flow back to the electrode part well due to the residual electric field, the stored elastic potential energy causes the liquid in the fluid deformation area to flow back to the electrode area, so that the next movement of the folding electrostatic hydraulic actuator 1 is consistent with the state of the previous movement.

[0061] The side panel 5 is a thin plate with an airfoil-shaped cross section, and an opening structure is provided at the front and end of the airfoil-shaped cross section. The front end of the opening structure extends slightly outward relative to the outer surface of the side panel, and the end extends outward relative to the inner side of the side panel, presenting two "chimney"-like structures as a whole. The limiting plate part 31 in the pectoral fin movable skeleton 3 is connected to the inside of the "chimney" in the side panel by gluing, thereby dividing the inside of the "chimney" into upper and lower sides. At the front end, the length of the skeleton part 331 in the "chimney" structure is shorter, while at the end, the length of the skeleton part 332 in the "chimney" structure is longer. The upper surfaces of the interior of the front and rear end "chimneys" are connected by gluing folding electrostatic hydraulic actuators 111 and 113, and the lower surfaces are also connected by gluing folding electrostatic hydraulic actuators 112 and 114. The "chimney" part located inside the side panel is used to accommodate the electrode area of ​​the folding electrostatic hydraulic drive 1, and the "chimney" part located outside the side panel maintains a certain distance from the deformation area of ​​the folding electrostatic hydraulic drive 111, 113 to provide stable support and avoid interfering with the deformation of the deformation area of ​​the folding electrostatic hydraulic drive.

[0062] like Figure 6As shown, when the folding electrostatic hydraulic driver 112 in the opening structure in the first skeleton part 331 that is adhered to the lower surface is energized, the folding electrostatic hydraulic driver 112 will cause the first skeleton part 331 to bend upward; when the folding electrostatic hydraulic driver 113 in the opening structure in the second skeleton part 332 that is adhered to the upper surface is energized, the folding electrostatic hydraulic driver 113 will cause the second skeleton part 332 to bend downward, and a phase difference is generated between the first skeleton part 331 and the second skeleton part 332, causing the soft silicone pectoral fin to form a wave, thereby generating a propulsion force.

[0063] The method for designing a foldable electrostatic fluid actuator according to manta ray related parameters of the present invention comprises the following steps:

[0064] (1) Determine the design parameters of the foldable electrostatic liquid actuator, including: the fluid deformation region includes two deformation chambers, the two deformation chambers are of equal length, the length of the deformation chamber in the fluid deformation region L1 = L0, the width of the foldable electrostatic liquid actuator W = W0, the length of the electrode in the electrode region L2 = L0, the DC voltage value U = 7000 V, and the liquid content V injected into the flexible oil storage sealing bag practice .

[0065] (2) Determine the amplitude θ of the manta ray's pectoral fin o =47°, wave number w=0.4 and frequency f=1.0 Hz, and a simulation model is established by scaling the pectoral fin of the real manta ray to a certain extent (2.5%), and then the maximum lift F of the pectoral fin under these parameters is calculated. l =0.17N;

[0066] Import the manta ray pectoral fin 3D model into Fluent, set a fluid domain of appropriate size, divide the mesh appropriately, use hexahedral mesh for the fluid domain, and use tetrahedral mesh for the interface between the pectoral fin model and the fluid domain.

[0067] The K-omega turbulence model was used, and the coupling of pressure and velocity in the continuity equation was solved using the Simple algorithm. The convergence residual κ was set to 1×10 -3 .

[0068] Set boundary conditions, the inlet boundary is set to velocity inlet, the outlet boundary is set to pressure outlet, and the surrounding areas are fixed walls.

[0069] The UDF module in the Fluent module is used to define the pectoral fin motion. The DEFINE_GRID_MOTION macro is used to define the motion of the grid nodes of the pectoral fin of the manta ray; the Compute_Force_And_Moment macro is used to access the coordinates, velocity, and pressure of the pectoral fin grid nodes. The number of time steps is set to 1600, the number of iterations is 100, and the time step is 0.005 for calculation.

[0070] After the residual κ converges, stop the calculation. Import the lift of the pectoral fin through the post-processing module of Fluent and calculate the maximum lift F of the pectoral fin in one movement cycle l =0.17N.

[0071] (3) According to the size of the pectoral fin active skeleton, the length L1 = 4 cm and the width W = 4 cm of the foldable electrostatic hydraulic actuator chamber and the length L2 = 4 cm of the electrode in the electrode area are preliminarily determined;

[0072] (4) Calculate the content of dielectric liquid when the driver is completely filled with dielectric liquid:

[0073]

[0074] (5) Determine the actual injected dielectric liquid content, V practice =V ideal ×n=14.64ml, n=60%.

[0075] (6) Calculate the maximum angle θ generated by the folding electrostatic hydraulic actuator according to the following formula max =48.54°:

[0076]

[0077] Where A is the cross-sectional area of ​​the folding drive, y max It is the maximum height of the folding actuator when it is deformed when powered on.

[0078] (7) Determine the maximum angle θ of the driver max and the optimal fluctuation amplitude θ of manta ray o relationship,

[0079] When θ max <θ o If yes, go to step (9), otherwise go to step (8);

[0080] (8) Determine the maximum angle θ of the driver max The optimal fluctuation amplitude of manta ray is 1.05θ o Relationship:

[0081] When θ max <1.05×θ o If yes, go to step (11), otherwise go to step (13);

[0082] (9) Determine V practice With V ideal If V practice ≤V ideal , go to step (10), otherwise go to step (12);

[0083] (10) Increasing the dielectric liquid content V in the foldable electrostatic hydraulic actuator zpractice , let n = n + 5%, and return to step (6);

[0084] (11) Calculate the drive output force:

[0085]

[0086] Elastic force of spring leaf

[0087]

[0088] Where ε0 is the dielectric constant of vacuum, ε r is the relative dielectric constant of the dielectric liquid, U is the driving voltage, I is the moment of inertia of the spring sheet, E is the elastic modulus of the spring sheet, and the process goes to step (16);

[0089] (12) Increase the length L1 of the actuator deformation chamber and return to step (4);

[0090] (13) reducing the length L1 of the actuator deformation chamber and returning to step (4);

[0091] (14) Increase the driving voltage value U, U∈[7000,12000], set U=U+1000V, and go to step (8). If U>12000V, go to step (15);

[0092] (15) Increase the length of the driver electrode area L2 = 12 cm, and return to step (11);

[0093] (16) Determine F and F l +2F elastic , if F<F l +2F elastic , then go to step (14), otherwise end.

Claims

1. A foldable electrostatic hydraulic actuator for bionic manta ray pectoral fins, characterized in that: It includes a flexible oil storage sealing bag, a dielectric fluid and an electrode. The flexible oil storage sealing bag is divided into an electrode area and a fluid deformation area. Electrodes are symmetrically attached to both sides of the flexible oil storage sealing bag in the electrode area, and the fluid deformation area includes two deformation chambers. When a voltage is applied to the electrode area, the upper and lower electrodes are attracted, the dielectric fluid flows from the electrode area to the fluid deformation area, and the two deformation chambers in the fluid deformation area expand.

2. The foldable electrostatic hydraulic actuator for bionic manta ray pectoral fins according to claim 1, characterized in that: A skirt is reserved around the sealing area of ​​the flexible oil storage sealing bag.

3. The foldable electrostatic hydraulic actuator for bionic manta ray pectoral fins according to claim 1, characterized in that: The electrode is a flexible electrode made of ion-conductive polyacrylamide hydrogel or a rigid electrode made of aluminum foil or copper foil; the area of ​​the electrode is not greater than the area of ​​the electrode region of the flexible oil storage sealing bag.

4. The foldable electrostatic hydraulic actuator for bionic manta ray pectoral fins according to claim 1, characterized in that: The dielectric fluid is vegetable transformer oil with good insulation and low viscosity.

5. A bionic manta ray pectoral fin, characterized in that: It includes pectoral fins, side panels, a pectoral fin movable frame, spring leaves, a skin and a foldable electrostatic hydraulic actuator as described in any one of claims 1 to 4, the front and rear ends of the pectoral fins are respectively passed through the pectoral fin movable frame on the side panels, the spring leaves are installed on both sides of the pectoral fin movable frame, the foldable electrostatic hydraulic actuator is symmetrically installed on both sides of the pectoral fin movable frame, and the outermost deformation chamber of the foldable electrostatic hydraulic actuator is fixed in the mounting groove of the side panel.

6. The bionic manta ray pectoral fin according to claim 5, characterized in that: The pectoral fin movable frame comprises a limiting plate, a soft joint and a frame, the pectoral fin is mounted on the frame, and the widths of the limiting plate, the frame and the soft joint are reduced in sequence.

7. The bionic manta ray pectoral fin according to claim 6, characterized in that: The projection of the spring sheet is located within the limiting plate, the soft joint and the frame for mounting the pectoral fin.

8. The bionic manta ray pectoral fin according to claim 6, characterized in that: The hardness of the restriction plate and the frame is the same, and the hardness of the soft joint is less than the hardness of the restriction plate and the frame.

9. The bionic manta ray pectoral fin according to claim 5, characterized in that: The mounting groove of the side plate is a variable diameter square hole, and the diameter of the square hole corresponding to the electrode area is smaller than the diameter of the square hole corresponding to the fluid deformation area.

10. A parameter design method for a foldable electrostatic hydraulic actuator for bionic manta ray pectoral fins, characterized in that: The following steps are involved: (1) Determine the design parameters of the foldable electrostatic liquid actuator. The fluid deformation region includes two deformation chambers. The two deformation chambers have equal lengths. The length of the deformation chamber in the fluid deformation region is L1 = L0. The width of the foldable electrostatic liquid actuator is W = W0. The DC voltage value is U. The length of the electrode in the electrode region is L2 = L0. The liquid content V injected into the flexible oil storage sealing bag is practice ; (2) Determine the amplitude θ of the manta ray's pectoral fin o , wave number w and frequency f, establish a simulation model, and calculate the maximum lift F of the pectoral fin under these parameters l ; (3) According to the size of the active skeleton of the pectoral fin, the length L1=L0, the width W=W0 of the deformation chamber of the foldable electrostatic hydraulic actuator and the length L2=L0 of the electrode in the electrode area are determined; (4) Calculate the content of dielectric liquid when the drive is completely filled (5) Determine the actual injected dielectric liquid content, V practice =V ideal ×n, n=60% (6) Calculate the maximum angle θ generated by the folding electrostatic hydraulic actuator max : Where A is the cross-sectional area of ​​the folding actuator. y max The maximum height of the folding actuator when it is deformed when powered on; (7) Determine the maximum angle θ of the driver max and the optimal fluctuation amplitude θ of manta rays o Relationship: When θ max <θ o If yes, go to step (9), otherwise go to step (8); (8) Determine the maximum angle θ of the driver max The optimal fluctuation amplitude of manta ray is 1.05θ o Relationship: When θ max <1.05×θ o If yes, go to step (11), otherwise go to step (13); (9) Determine V practice With V ideal If V practice ≤V ideal , go to step (10), otherwise go to step (12); (10) Increasing the dielectric liquid content V in the foldable electrostatic hydraulic actuator zpractice , let n = n + 5%, and return to step (6); (11) Calculate the drive output force: Elastic force of spring leaf Where ε0 is the dielectric constant of vacuum, ε r is the relative dielectric constant of the dielectric liquid, U is the driving voltage, I is the moment of inertia of the spring sheet, E is the elastic modulus of the spring sheet, and the process goes to step (16); (12) Increase the length L1 of the actuator deformation chamber and return to step (4); (13) reducing the length L1 of the actuator deformation chamber and returning to step (4); (14) Increase the driving voltage value U, U∈[7000,12000], set U=U+1000V, and go to step (8). If U>12000V, go to step (15); (15) Increase the length L2 of the driver electrode area and return to step (11); (16) Determine F and F l +2F elastic , if F<F l +2F elastic , then go to step (14), otherwise end.

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