Underwater swimming robot based on dielectric elastomer and driving method thereof

Abstract

The application discloses an underwater swimming robot based on a dielectric elastomer and a driving method thereof. The underwater robot structure comprises a flexible hydraulic pump, a hydraulic flexible gripper, a silica gel shell, a control module, a bionic fish tail structure and a solenoid valve. The flexible hydraulic pump body is composed of a dielectric elastomer. When electrified, the dielectric elastomer changes in length and diameter directions. The driving method comprises the following steps: injecting water pressure into the hydraulic flexible gripper by a flexible hydraulic system with one-way water supply realized by cooperating with a one-way valve, expanding the hydraulic flexible gripper inside to realize a gripping action, opening the solenoid valve to release the clamping method; and utilizing the change in the length direction of the dielectric elastomer, limiting the deformation of one side, so that the bionic fish tail structure which can swing in two directions drives the overall movement. The application replaces the traditional hydraulic system with the flexible hydraulic system as an independent driving source. The control and driving system is integrated inside, and the influence of the wire harness on the movement performance of the robot is eliminated.

Description

Technical Field

[0001] This invention relates to the field of soft robot technology, and in particular to an underwater robot based on a dielectric elastomer and its driving method. Background Technology

[0002] Hydraulic power systems have many advantages, such as (1) they can provide high power output and meet the needs of high power transmission; (2) they have a simple structure and few parts, thus having high reliability and stability; (3) they can achieve precise control by adjusting hydraulic valves and pumps; and (4) they are suitable for various working environments and conditions, such as high temperature and high pressure. Therefore, hydraulic power systems are widely used in robot manufacturing, transportation, heavy machinery and energy recovery. Among these, flexible biomimetic fluid robots have the advantages of hydraulic systems, which enable them to have large deformation and high load, and these characteristics allow fluid robots to adapt to various working scenarios, such as hydraulic grippers, dexterous hands, medical rehabilitation devices, underwater propulsion actuators, etc. Multiple factors affect the output performance of these devices, among which the output characteristics of pumps or compressors will directly affect the response performance of fluid robots.

[0003] Traditional flexible fluid robots use rigid pumps or air compressors as their power source. While rigid pumps provide strong power, they are bulky and cumbersome compared to flexible and compact actuators. Their working principle also makes miniaturization and weight reduction difficult, hindering the integration and agile movement of hydraulic robots. In contrast, flexible hydraulic pumps are lightweight and compact, playing a crucial role in wearable devices, biomedicine, and disaster relief. Various soft materials, including smart gels, responsive elastomers, and shape memory polymers, have been used to develop flexible pumps, but electrically driven flexible pumps that combine high performance and multi-fluid adaptability remain relatively scarce. Compared to other materials, dielectric elastomers (DEAs) exhibit rapid response, large deformation, high flexibility, and low power loss. Flexible hydraulic pumps based on DEAs can be used to integrate hydraulic systems, improving equipment operability and environmental adaptability.

[0004] Dielectric elastomer actuators consist of a dielectric elastomer film and flexible electrodes coated on its upper and lower surfaces. Under the influence of an electric field, positive and negative charges accumulate on the upper and lower surfaces of the film, forming Maxwell stress, which triggers reversible deformation of the elastomer film to convert electrical energy into mechanical energy. High energy density, fast response speed, large deformation, and light weight are its outstanding advantages. It has enormous application potential in fields such as biomimetic robot design and the development of wearable sensing and monitoring systems. Especially in the field of soft robot design and fabrication, dielectric elastomers are a crucial material foundation for achieving lightweight, wearable, and intelligent actuators in the future.

[0005] However, traditional dielectric elastomer hydraulic pumps still lack organic integration with soft robots. This is because dielectric elastomers are difficult to power without an external high-voltage power source. To achieve cableless operation, a small boost circuit board needs to be designed, and the circuit board's power is supplied by a battery. At the same time, the complex driving principle reduces the system's robustness, and the cumbersome structure also limits the design of the robot carrier. Summary of the Invention

[0006] To address the problems existing in the background art, the present invention provides an underwater swimming robot based on a dielectric elastomer and its driving method.

[0007] The technical solution adopted in this invention is: I. An underwater swimming robot based on a dielectric elastomer Includes a flexible hydraulic pump, a hydraulic flexible gripper, a silicone shell, a control module, a biomimetic fish tail structure, and a solenoid valve; The silicone shell has an internal cavity housing the flexible hydraulic pump, control module, and solenoid valve. One end of the flexible hydraulic pump extends through the silicone shell via a first guide pipe and connects to the water inlet of the hydraulic flexible gripper located in front of the silicone shell. The other end of the flexible hydraulic pump extends through the silicone shell via a second guide pipe and connects to the external water environment. The biomimetic fish tail structure is located behind the silicone shell and connects to the second guide pipe. The water outlet of the hydraulic flexible gripper extends through the silicone shell via a third guide pipe and connects to one end of the solenoid valve located inside the silicone shell. The other end of the solenoid valve extends through the silicone shell via a fourth guide pipe and connects to the external water environment. The control module is electrically connected to the solenoid valve, the flexible hydraulic pump, and the biomimetic fish tail structure.

[0008] The flexible hydraulic pump includes a central multilayer dielectric elastomer tubular actuator, two check valves, two straight-through pagoda water pipe joints, a fifth guide pipe, and a sixth guide pipe; The two straight-through pagoda water pipe connectors are respectively connected to the two ends of the central multilayer dielectric elastomer tubular actuator. One end of each straight-through pagoda water pipe connector is connected to the central multilayer dielectric elastomer tubular actuator, and the other end is connected to the corresponding one-way valve through the fifth / sixth guide pipe. The two ends of the central multilayer dielectric elastomer tubular actuator are connected. Under the action of the two one-way valves, the water flow inside the flexible hydraulic pump flows from the bionic fish tail structure to the direction of the hydraulic flexible gripper.

[0009] The hydraulic flexible gripper includes two symmetrically arranged hydraulic flexible actuators and a four-way valve; The four-way valve has four valve ports, two of which are used to connect to two symmetrically arranged hydraulic flexible actuators in a "V" shape, and the remaining two valve ports are used as the water inlet and outlet of the hydraulic flexible gripper, respectively. Each hydraulic flexible actuator has a deformable layer on one side and a passive bending layer on the other side. The deformable layer consists of multiple rectangular protrusions spaced apart along the length direction, and the passive bending layer is a rectangular surface. The passive bending layer of each hydraulic flexible actuator is arranged inward, and the deformable layer is arranged outward.

[0010] When the hydraulic flexible gripper clamps, water flows into each hydraulic flexible actuator through the corresponding valve port. When the solenoid valve is closed, the water outlet of the hydraulic flexible gripper is closed, which in turn increases the pressure inside the two hydraulic flexible actuators. This causes the deformation layer of each hydraulic flexible actuator to bend outward. The passive bending layer is driven by the deformation layer to bend outward together. The two hydraulic flexible actuators, which are in the shape of a "V", bend into the shape of an "O" to achieve the clamping function. When the hydraulic flexible gripper is released, the solenoid valve opens, causing the water outlet of the hydraulic flexible gripper to open. Water flows out from the two hydraulic flexible actuators, thereby releasing the pressure inside the two hydraulic flexible actuators. The two hydraulic flexible actuators, which were in an "O" shape, return to a "V" shape, thus realizing the release function.

[0011] The biomimetic fish tail structure includes two tail-end multilayer dielectric elastomer tubular actuators, an adapter, a flexible flapping wing film, and a bendable rigid passive layer film. The two tail-end multilayer dielectric elastomer tubular actuators are arranged in parallel with a gap, and both ends on the same side are connected to the adapter. The two tail-end multilayer dielectric elastomer tubular actuators are connected by a flexible rigid passive layer film, and the flexible rigid passive layer film and the two tail-end multilayer dielectric elastomer tubular actuators are arranged in parallel. The flexible rigid passive layer film is Y-shaped at the end away from the adapter, and flexible flapping wing films are arranged in the fan-shaped area formed by the two protruding ends of the Y-shape.

[0012] Both the middle multilayer dielectric elastomer tubular actuator and the tail multilayer dielectric elastomer tubular actuator include dielectric elastomers. When a voltage is applied, the dielectric elastomers elongate and deform in both the length and radial directions from their initial state. When the voltage is removed, they return to their initial state. The central multilayer dielectric elastomer tubular actuator expands and deforms after voltage is applied, and water is drawn from the external water environment into the cavity of the central multilayer dielectric elastomer tubular actuator. After the voltage is removed, it recovers its deformation and, under the action of restoring force, squeezes the water in the cavity of the central multilayer dielectric elastomer tubular actuator into the hydraulic flexible gripper. The tail-end multilayer dielectric elastomer tubular actuator is divided into two layers along the width direction, namely the first layer and the second layer. After applying voltage to the first layer / second layer, the first layer / second layer expands and deforms from the initial state, while the second layer / first layer remains in the initial state without voltage applied. This causes the tail-end multilayer dielectric elastomer tubular actuator to bend and deform towards the second layer / first layer from the initial state, thereby driving the flexible rigid passive layer film and the flexible flapping wing film to bend and deform towards the second layer / first layer from the initial state. After the voltage is removed from the first / second layer, the deformation is restored to the initial state, causing the tail-end multilayer dielectric elastomer tubular actuator to restore its initial state; thereby driving the flexible rigid passive layer film and the flexible flapping wing film to restore their initial states.

[0013] The control module includes a control circuit board, a boost circuit board, and a manual switch; The control circuit board includes a main battery, a voltage regulator module, a main control board, and a power switch circuit. The main battery is electrically connected to the manual switch, the manual switch is electrically connected to the voltage regulator module, the voltage regulator module is electrically connected to the main control board, the power switch circuit is electrically connected to the main control board, the manual switch and the solenoid valve respectively, the boost circuit board is electrically connected to the flexible hydraulic pump and the bionic fish tail structure respectively, and the manual switch is electrically connected to the boost circuit board.

[0014] II. A Driving Method for an Underwater Robot Based on a Dielectric Elastomer The driving method includes a clamping method and a motion method, wherein the motion method is as follows: S1.1: Apply voltage to a portion of the bionic fish tail structure through the control module, causing the bionic fish tail structure to bend and deform to one side based on its basic state. Then, remove the voltage through the control module, and the bionic fish tail structure returns to its initial state. S1.2: Repeat step S1.1, but apply voltage to a different part, causing the bionic fish tail structure to bend in the opposite direction to step S1.1; S1.3: Repeat steps S1.1 to S1.2, the biomimetic fish tail structure generates a thrust in the direction of the hydraulic flexible gripper, thereby realizing the movement of the dielectric elastomer underwater robot; The specific motion method is as follows: Step S1.1 is as follows: The voltage of the main battery is boosted by the boost circuit board and applied to the first / second layer of each of the two tail-end multilayer dielectric elastomer tubular actuators of the biomimetic fish tail structure. This causes both tail-end multilayer dielectric elastomer tubular actuators to bend and deform towards their respective second / first layers, thereby causing the flexible rigid passive layer film and the flexible flapping wing film to bend and deform towards the second / first layers from their initial state. After the voltage is removed from the first / second layers, the deformation returns to the initial state, causing the tail-end multilayer dielectric elastomer tubular actuators to return to their initial state, and thus causing the flexible rigid passive layer film and the flexible flapping wing film to return to their initial state. Step S1.2 specifically includes: The voltage of the main battery is applied to the second / first layer of each of the two multilayer dielectric elastomer tubular actuators at the tail of the bionic fish tail structure after passing through the boost circuit board. The rest of the process is the same as step S1.1, so that the flexible rigid passive layer film and the flexible flapping wing film bend in the opposite direction to step S1.1. Step S1.3 specifically includes: S1.3: Repeat steps S1.1 to S1.2. The flexible flapping wing membrane in the biomimetic fish tail structure continuously bends and oscillates, thereby generating forward thrust. By changing the duration of the voltage applied in steps S1.1 / S1.2, the degree of bending of the flexible flapping wing membrane towards the direction of steps S1.1 / S1.2 can be achieved, thus realizing movement in the direction of lower bending degree. The clamping method is as follows: S2.1: The control module applies voltage to the flexible hydraulic pump, and water is drawn into the flexible hydraulic pump from the external water environment. After the voltage is removed, the water in the flexible hydraulic pump is squeezed into the hydraulic flexible gripper. The control module controls the solenoid valve to close, so that the hydraulic flexible gripper bends and deforms from the initial state to clamp the object. S2.2: The solenoid valve is opened by controlling the control module, so that the water in the hydraulic flexible gripper flows out through the solenoid valve, restoring the deformation and releasing the object to its initial state.

[0015] Step 2.1 specifically involves: The voltage of the main battery is boosted by the boost circuit board and applied to the central multilayer dielectric elastomer tubular actuator in the flexible hydraulic pump. Through expansion and deformation, the water from the external water environment flows into the cavity of the central multilayer dielectric elastomer tubular actuator through the second guide pipe. After the voltage is removed, the deformation is restored, and under the action of the restoring force, the water in the cavity of the central multilayer dielectric elastomer tubular actuator flows into the inlet of the four-way valve and then into each hydraulic flexible actuator through the corresponding valve port. The power switch circuit controls the solenoid valve to close, thereby closing the outlet of the four-way valve, which in turn increases the pressure inside the two hydraulic flexible actuators. As a result, the deformation layer of each hydraulic flexible actuator undergoes outward bending deformation, and the passive bending layer is driven by the deformation layer to bend outward as well. The two hydraulic flexible actuators, which are in the shape of a "V", are bent and deformed into an "O" shape to clamp the object. Step 2.2 specifically involves: The control solenoid valve opens, causing the outlet of the four-way valve to open. Water flows from the two hydraulic flexible actuators through their respective valve ports and out through the outlet of the four-way valve. It then passes through the solenoid valve back to the external water environment, thereby releasing the internal pressure of the two hydraulic flexible actuators. The two hydraulic flexible actuators, which were in an "O" shape, return to a "V" shape and release the object.

[0016] The beneficial effects of this invention are: This invention replaces traditional hydraulic valves with a flexible hydraulic system incorporating multilayer dielectric elastomers as an independent drive source for a hydraulic flexible gripper. This flexible hydraulic system injects water pressure into the gripper, causing it to expand and grasp. When pressure needs to be released to release the grasped object, only a solenoid valve needs to be opened to release the internal water pressure of the hydraulic actuator. After depressurization, the internal volume of the gripper returns to its initial state. Because it uses external water as the hydraulic medium, it eliminates the dependence on a water tank in the hydraulic drive system. The biomimetic fishtail structure consists of two tubular dielectric elastomer actuators. By utilizing the changes in the length direction of the multilayer dielectric elastomer tubular actuators and limiting deformation on one side, a bidirectional swinging biomimetic fishtail structure is designed to help the robot move underwater. Thanks to the advantage of the multilayer dielectric elastomer actuators being able to operate at lower voltages, this underwater robot integrates a control and drive system, eliminating the influence of wiring harnesses on the robot's motion performance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a partial explosion of an underwater robot based on a dielectric elastomer, as described in this invention. Figure 2 This is an assembly diagram of an underwater robot based on a dielectric elastomer according to the present invention. Figure 3This is an internal layout diagram of an underwater robot based on a dielectric elastomer, as described in this invention. Figure 4 This is a diagram showing the deformation of a tubular actuator for an underwater robot based on a dielectric elastomer, as described in this invention. Figure 5 This is an exploded view of a flexible hydraulic pump for an underwater robot based on a dielectric elastomer, as described in this invention. Figure 6 This is an exploded view of a hydraulic flexible gripper for an underwater swimming robot based on a dielectric elastomer, as described in this invention. Figure 7 This is a schematic diagram showing the distribution of the inlet and outlet of the hydraulic flexible gripper of an underwater robot based on a dielectric elastomer, as described in this invention. Figure 8 This is a schematic diagram of the grasping and releasing action of a hydraulic flexible gripper for an underwater robot based on a dielectric elastomer, as described in this invention. Figure 9 This is a cross-sectional view of a hydraulic flexible actuator for an underwater robot based on a dielectric elastomer, as described in this invention. Figure 10 This is an exploded view of the control circuit board of a dielectric elastomer-based underwater robot according to the present invention. Figure 11 This is a system structure block diagram of an underwater swimming robot based on a dielectric elastomer according to the present invention; Figure 12 An exploded view of a biomimetic fish tail structure for an underwater robot based on a dielectric elastomer, as described in this invention. Figure 13 This is a schematic diagram of the biomimetic fish tail mechanism driving a bionic underwater robot based on a dielectric elastomer, as described in this invention.

[0018] In the diagram: 1. Flexible hydraulic pump; 2. Hydraulic flexible gripper; 3. Silicone shell; 5. Control circuit board; 6. Boost circuit board; 7. Solenoid valve; 8. Bionic fish tail structure; 9. Manual switch; 10. Infrared receiver module; 1-1. One-way valve; 1-2. Straight-through pagoda water pipe connector; 1-3. Middle multilayer dielectric elastomer tubular actuator; 2-1. Hydraulic flexible actuator; 2-2. Four-way valve; 5-1. Main battery; 5-2. Voltage regulator module; 5-3. Main control board; 5-4. Power switch circuit; 5-5. PCB circuit board; 8-1. Adapter; 8-2. Flexible rigid passive layer film; 8-3. Flexible flapping wing film; 8-4. Tail multilayer dielectric elastomer tubular actuator. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0022] This invention proposes an underwater swimming robot based on a dielectric elastomer, such as... Figure 1 , Figure 2 and Figure 3 As shown, an underwater swimming robot based on dielectric elastomer includes a flexible hydraulic pump 1, a hydraulic flexible gripper 2, a silicone shell 3, a control module, a biomimetic fish tail structure 8, and a solenoid valve 7. The silicone shell 3 has an internal cavity containing a flexible hydraulic pump 1, a control module, and a solenoid valve 7. One end of the flexible hydraulic pump 1 passes through the front end of the silicone shell 3 via a first guide pipe and connects to the water inlet of the hydraulic flexible gripper 2 located in front of the silicone shell 3. The other end of the flexible hydraulic pump 1 passes through the rear end of the silicone shell 3 via a second guide pipe and connects to the external water environment. The bionic fish tail structure 8 is located behind the silicone shell 3 and connected to the second guide pipe. The water outlet of the hydraulic flexible gripper 2, which is located on the same side as the water inlet, passes through the front end of the silicone shell 3 via a third guide pipe and connects to one end of the solenoid valve 7 located inside the silicone shell 3. The other end of the solenoid valve 7 passes through the lower end of the silicone shell 3 via a fourth guide pipe and connects to the external water environment. The control module is electrically connected to the solenoid valve 7, the flexible hydraulic pump 1, and the bionic fish tail structure 8.

[0023] The silicone housing 3 is preferably made using the Ecoflex-30 specification. The solenoid valve 7 preferably has an operating voltage of 3.3V.

[0024] like Figure 5 As shown, the flexible hydraulic pump 1 includes a central multilayer dielectric elastomer tubular actuator 1-3, two check valves 1-1, two straight-through pagoda water pipe joints 1-2, a fifth guide pipe, and a sixth guide pipe; Two straight-through pagoda water pipe connectors 1-2 are respectively connected to the two ends of the central multilayer dielectric elastomer tubular actuator 1-3. One end of each straight-through pagoda water pipe connector 1-2 is connected to the central multilayer dielectric elastomer tubular actuator 1-3, and the other end of each straight-through pagoda water pipe connector 1-2 is connected to the inlet / outlet of the corresponding one-way valve 1-1 through the fifth guide pipe / sixth guide pipe. The two ends of the central multilayer dielectric elastomer tubular actuator 1-3 are connected, allowing the liquid to flow inside. Under the action of the two one-way valves 1-1, the water inside the flexible hydraulic pump 1 flows from the bionic fish tail structure 8 to the hydraulic flexible gripper 2.

[0025] Specifically, the inlet of one of the one-way valves 1-1 is connected to the external water environment, and the outlet is connected to the corresponding straight-through pagoda water pipe joint 1-2 through the fifth guide pipe; the inlet of the other one-way valve 1-1 is connected to the corresponding straight-through pagoda water pipe joint 1-2 through the sixth guide pipe, and the outlet is connected to the inlet of the hydraulic flexible gripper 2 through the first guide pipe.

[0026] Specifically, the one-way valve 1-1 functions as a directional liquid conveyor. The liquid flows in from the inlet of the one-way valve 1-1, passes through the flexible hydraulic pump 1, and then flows directionally into the hydraulic flexible gripper 2. Simultaneously, because it uses the external water environment as the hydraulic medium, it eliminates the dependence on a water tank in the hydraulic drive system. Preferably, the opening pressure of the one-way valve 1-1 is 0 MPa.

[0027] Specifically, the guide tube is made of silicone, with the preferred silicone tube having an inner diameter of 3mm and an outer diameter of 4mm.

[0028] like Figure 6 As shown, the hydraulic flexible gripper 2 includes two symmetrically arranged hydraulic flexible actuators 2-1 and a four-way valve 2-2; like Figure 7 As shown, the four-way valve 2-2 has four valve ports, two of which are used to connect to two symmetrically arranged hydraulic flexible actuators 2-1 in a “V” shape, and the remaining two valve ports are used as the inlet and outlet of the hydraulic flexible gripper 2, respectively. The two hydraulic flexible actuators 2-1 are integrally cast from silicone material using a special mold. The preferred silicone material is Ecoflex-30, and all connections are sealed to prevent water leakage. The four-way valve 2-2 is fabricated using 3D printing technology.

[0029] Each hydraulic flexible actuator 2-1 has a deformation layer on one side and a passive bending layer on the other side. The deformation layer consists of multiple rectangular protrusions spaced apart along the length direction, and the passive bending layer consists of a regular rectangular surface. The passive bending layer is oriented inward, and the deformation layer is oriented outward. In addition, the passive bending layer of each hydraulic flexible actuator 2-1 is arranged inward, and the deformation layer is arranged outward.

[0030] Specifically, such as Figure 8 As shown, each hydraulic flexible actuator 2-1 is cast from a specially made mold, which is manufactured using 3D printing technology. Because the hydraulic flexible actuator 2-1 has a cavity of a specific shape inside, the mold includes a concave mold, a convex mold, and a bottom encapsulation film, such as... Figure 8 As shown, since the hydraulic flexible actuator 2-1 has a cavity of a specific shape inside, it needs to be manufactured through two steps. The first step is to use a concave mold and a convex mold to form the internal cavity, wherein the concave mold is used to form the outer contour of the hydraulic flexible actuator 2-1 and the convex mold is used to form the inner contour of the hydraulic flexible actuator 2-1. The second step is to use a bottom encapsulation film to form the passive layer for directional bending of the hydraulic flexible actuator 2-1 and the closed cavity.

[0031] like Figure 9As shown, when the hydraulic flexible gripper 2 clamps, water flows into each hydraulic flexible actuator 2-1 through the corresponding valve port. The solenoid valve 7 is closed, which closes the outlet of the hydraulic flexible gripper 2, meaning that the water cannot flow from the outlet. Consequently, the pressure inside both hydraulic flexible actuators 2-1 increases due to the inflow of water, causing the deformation layer of each hydraulic flexible actuator 2-1 to bend outward. The passive bending layer is driven by the deformation layer to bend outward in the direction of the deformation layer. Specifically, the middle of the passive bending layer bends outward, while the end bends inward. Since the two hydraulic flexible actuators 2-1 are symmetrically arranged, the two hydraulic flexible actuators 2-1, which are in the shape of a "V", achieve the clamping function by bending and deforming into an "O" shape. When the hydraulic flexible gripper 2 is released, the solenoid valve 7 opens, causing the outlet of the hydraulic flexible gripper 2 to open. Water flows out from the two hydraulic flexible actuators 2-1, thereby releasing the pressure inside the two hydraulic flexible actuators 2-1. The two hydraulic flexible actuators 2-1, which were in an "O" shape, return to a "V" shape, thus realizing the release function.

[0032] like Figure 12 As shown, the biomimetic fish tail structure 8 includes two tail-end multilayer dielectric elastomer tubular actuators 8-4, an adapter 8-1, a flexible flapping wing film 8-3, and a bendable rigid passive layer film 8-2. Two tail-end multilayer dielectric elastomer tubular actuators 8-4 are arranged in parallel at intervals, and both ends on the same side are connected to the adapter 8-1 and sealed. The two tail-end multilayer dielectric elastomer tubular actuators 8-4 are connected by a flexible rigid passive layer film 8-2, and the flexible rigid passive layer film 8-2 and the two tail-end multilayer dielectric elastomer tubular actuators 8-4 are arranged in parallel. The flexible rigid passive layer film 8-2 is Y-shaped at the end away from the adapter 8-1. The fan-shaped area formed by the two protruding ends of the Y-shape is covered with a flexible flapping wing film 8-3. The flexible flapping wing film 8-3 is perpendicular to the line connecting the two tail-end multilayer dielectric elastomer tubular actuators 8-4.

[0033] Preferably, the flexible rigid passive layer film 8-2 is made of polyethylene terephthalate with a thickness of 100 μm, and the flexible flapping wing film 8-3 is made of polydimethylsiloxane with a thickness of 100 μm. Both are cut into the preset shape by laser cutting.

[0034] Both the middle multilayer dielectric elastomer tubular actuator 1-3 and the tail multilayer dielectric elastomer tubular actuator 8-4 include dielectric elastomers, such as... Figure 4As shown, the dielectric elastomers all undergo elongation deformation in both the length and radial directions after a voltage is applied, and return to their initial state after the voltage is removed. The black parts are carbon nanotubes sprayed onto a single-layer dielectric elastomer film. Because they have electrical conductivity, they are used as electrode materials. In real life, because they are black, black pigment is used to fill them in the drawing.

[0035] The central multilayer dielectric elastomer tubular actuator 1-3 expands and deforms after voltage is applied, and water is drawn from the external water environment into the cavity of the central multilayer dielectric elastomer tubular actuator 1-3. After the voltage is removed, it recovers its deformation and, under the action of restoring force, squeezes the water in the cavity of the central multilayer dielectric elastomer tubular actuator 1-3 into the hydraulic flexible gripper, thereby acting as a pump. like Figure 13 As shown, the tail-end multilayer dielectric elastomer tubular actuator 8-4 is divided into two layers along the width direction, namely the first layer and the second layer. After applying voltage to the first layer / second layer, the first layer / second layer expands and deforms from the initial state, that is, it elongates in the length direction. The second layer / first layer does not apply voltage and remains in the initial state, acting as an impedance. This causes the tail-end multilayer dielectric elastomer tubular actuator 8-4 to bend and deform towards the second layer / first layer from the initial state. This, in turn, causes the flexible rigid passive layer film 8-2 and the flexible flapping wing film 8-3 to bend and deform towards the second layer / first layer from the initial state. After the voltage is removed from the first / second layer, the deformation is restored to the initial state, causing the tail-end multilayer dielectric elastomer tubular actuator 8-4 to be restored to its initial state; in turn, it drives the flexible rigid passive layer film 8-2 and the flexible flapping wing film 8-3 to be restored to their initial state.

[0036] Specifically, the thickness of the single-layer dielectric elastomer is controlled at 10-20µm. Acrylic-based dielectric elastomers are commonly used dielectric elastomer materials. Reducing the film thickness can effectively increase the electric field obtained under the same voltage stimulation, thus achieving greater deformation. Similarly, reducing the film thickness can effectively reduce the voltage required under the same electric field driving conditions, reducing the design requirements of the hardware circuit board. When the thickness of the single-layer film is controlled at 10-20µm, the multilayer dielectric elastomer tubular actuator can achieve cavity expansion and length extension under a voltage of 200-500V. To facilitate the quick disassembly and liquid exchange of the central multilayer dielectric elastomer tubular actuator 1-3, straight-through pagoda-shaped water pipe connectors 1-2 are connected to both ends for easy disassembly and connection to the one-way valve. All connections are sealed to prevent liquid leakage.

[0037] like Figure 10 As shown, the control module includes a control circuit board 5, a boost circuit board 6, and a manual switch 9; The control circuit board 5 includes a main battery 5-1, a PCB circuit board 5-5, a voltage regulator module 5-2, a main control board 5-3, and a power switch circuit 5-4; like Figure 11 As shown, the main battery 5-1 provides power to the robot and is electrically connected to the manual switch 9, which controls the power-on and power-off states of the robot system. The manual switch 9 is electrically connected to the voltage regulator module 5-2, which in turn is electrically connected to the main control board 5-3. The voltage regulator module 5-2 has both boost and regulation functions; the boost function increases the voltage to the driving voltage of the main control board 5-3 and then regulates it. The power switch circuit 5-4 is electrically connected to the main control board 5-3, the manual switch 9, and the solenoid valve 7. The opening and closing of the power switch circuit 5-4 is controlled by the main control board 5-3. The PCB circuit board 5-5 serves as a support component, integrating the main battery 5-1, the voltage regulator module 5-2, the main control board 5-3, and the power switch circuit 5-4. The boost circuit board 6 is electrically connected to the flexible hydraulic pump 1 and the bionic fish tail structure 8 to provide high-voltage electricity. The manual switch 9 is electrically connected to the boost circuit board 6 to supply the voltage from the main battery 5-1 to the boost circuit board 6.

[0038] Specifically, the boost circuit board 6 utilizes a flyback boost module to boost the voltage of the main battery 5-1 to a square wave voltage of 0-500V. By multiplexing three sets of flyback boost modules, it has three output ports, which can independently drive three dielectric elastomer drives. The boost circuit board has a built-in wireless communication module for easy remote control by a host computer.

[0039] Specifically, it also includes an infrared receiving module 10, which is connected to the main control board 5-3. The infrared receiving module 10 transmits the received infrared signal back to the main control board 5-3. Based on the transmitted signal, the main control board 5-3 controls the opening and closing state of the power switch circuit 5-4, thereby controlling the on / off state of the solenoid valve.

[0040] A driving method for an underwater robot based on a dielectric elastomer is as follows: This includes clamping methods and motion methods. The motion method is as follows: S1.1: Apply voltage to a part of the bionic fish tail structure 8 through the control module, so that the bionic fish tail structure 8 bends and deforms on the basis of the basic state, bending to one side. Then, remove the voltage through the control module, and the bionic fish tail structure 8 returns to the initial state. Step S1.1 is as follows: The voltage of the main battery 5-1 is boosted by the boost circuit board 6 and applied to the first / second layer of each of the two tail-end multilayer dielectric elastomer tubular actuators 8-4 of the bionic fish tail structure 8. Each first / second layer expands and deforms from its initial state, that is, it elongates in the length direction. Each second / first layer, without voltage applied, remains in its initial state and acts as an impedance, causing both tail-end multilayer dielectric elastomer tubular actuators 8-4 to bend and deform in the direction of their respective second / first layers, that is, in the same direction. This, in turn, causes the flexible rigid passive layer film 8-2 and the flexible flapping wing film 8-3 to bend and deform in the direction of the second / first layers from their initial state. After the voltage is removed from the first / second layers, they return to their initial state, causing the tail-end multilayer dielectric elastomer tubular actuators 8-4 to return to their initial state as a whole. This, in turn, causes the flexible rigid passive layer film 8-2 and the flexible flapping wing film 8-3 to return to their initial state as a whole. S1.2: Repeat step S1.1, but apply voltage to a different part, causing the bionic fish tail structure 8 to bend in the opposite direction to step S1.1; Step S1.2 specifically includes: The voltage of the main battery 5-1 is applied to the second / first layer of the two tail-end multilayer dielectric elastomer tubular actuators 8-4 after passing through the boost circuit board 6. The rest of the process is the same as step S1.1, so that the flexible rigid passive layer film 8-2 and the flexible flapping wing film 8-3 bend in the opposite direction to step S1.1. S1.3: Repeat steps S1.1 to S1.2, and the biomimetic fish tail structure 8 generates a thrust in the direction of the hydraulic flexible gripper 2, thereby realizing the movement of the dielectric elastomer underwater robot. Step S1.3 specifically includes: S1.3: Repeat steps S1.1 to S1.2. The flexible flapping wing film 8-3 in the bionic fish tail structure 8 continuously bends and swings left and right, thereby generating a forward thrust. By changing the duration of the voltage applied in steps S1.1 / S1.2, the degree of bending of the flexible flapping wing film 8-3 in the direction of steps S1.1 / S1.2 can be achieved, thereby realizing the movement in the direction of lower bending degree.

[0041] The clamping method is as follows: S2.1: The control module applies a periodic voltage to the flexible hydraulic pump 1, and water is drawn into the flexible hydraulic pump 1 from the external water environment. After the periodic voltage is removed, the water in the flexible hydraulic pump 1 is squeezed into the hydraulic flexible gripper 2. The control module controls the solenoid valve 7 to close, so that the hydraulic flexible gripper 2 can bend and deform to clamp the object from the initial state. Step 2.1 specifically involves: The voltage of the main battery 5-1 is boosted by the boost circuit board 6 and applied to the central multilayer dielectric elastomer tubular actuator 1-3 in the flexible hydraulic pump 1. Through expansion and deformation, water from the external environment flows through the second guide pipe into the cavity of the central multilayer dielectric elastomer tubular actuator 1-3. After the voltage is removed, it returns to its original shape, and under the action of restoring force, the water in the cavity of the central multilayer dielectric elastomer tubular actuator 1-3 flows into the inlet of the four-way valve 2-2 and then into each hydraulic flexible actuator 2-1 through the corresponding valve port. The solenoid valves are controlled by the power switch circuit 5-4. 7. Closing the outlet of the four-way valve 2-2 prevents water from flowing out, thus increasing the pressure inside both hydraulic flexible actuators 2-1 due to the inflow of water. This causes the deformation layer of each hydraulic flexible actuator 2-1 to bend outward. The passive bending layer is driven by the deformation layer to bend outward in the direction of the deformation layer. Specifically, the middle of the passive bending layer bends outward, while the ends bend inward. Since the two hydraulic flexible actuators 2-1 are symmetrically arranged, the two hydraulic flexible actuators 2-1, which are in a "V" shape, clamp the object in an "O" shape through bending deformation. S2.2: The solenoid valve (7) is opened by controlling the control module, so that the water in the hydraulic flexible gripper (2) flows out through the solenoid valve (7), and the object is released after restoring its initial state.

[0042] Step 2.2 specifically involves: The main control board 5-3 sends a signal to the power switch circuit 5-4 to control the solenoid valve 7 to open, which opens the outlet of the four-way valve 2-2. Water flows from the two hydraulic flexible actuators 2-1 through their respective valve ports and out through the outlet of the four-way valve 2-2. Then it passes through the solenoid valve 7 back to the external water environment, thereby releasing the internal pressure of the two hydraulic flexible actuators 2-1. The two hydraulic flexible actuators 2-1, which were in an "O" shape, return to a "V" shape and release the object.

Claims

1. An underwater swimming robot based on a dielectric elastomer, characterized in that: The system includes a flexible hydraulic pump (1), a hydraulic flexible gripper (2), a silicone shell (3), a control module, a biomimetic fish tail structure (8), and a solenoid valve (7). The silicone shell (3) has an internal cavity containing the flexible hydraulic pump (1), the control module, and the solenoid valve (7). One end of the flexible hydraulic pump (1) passes through the silicone shell (3) via a first guide pipe and connects to the inlet of the hydraulic flexible gripper (2) located in front of the silicone shell (3). The other end of the flexible hydraulic pump (1) passes through a second guide pipe. The silicone shell (3) is connected to the external water environment. The bionic fish tail structure (8) is located behind the silicone shell (3) and connected to the second guide pipe. The outlet of the hydraulic flexible gripper (2) passes through the third guide pipe into the silicone shell (3) and is connected to one end of the solenoid valve (7) located inside the silicone shell (3). The other end of the solenoid valve (7) passes through the fourth guide pipe out of the silicone shell (3) and is connected to the external water environment. The control module is electrically connected to the solenoid valve (7), the flexible hydraulic pump (1) and the bionic fish tail structure (8) respectively.

2. The underwater swimming robot based on a dielectric elastomer according to claim 1, characterized in that: The flexible hydraulic pump (1) includes a central multilayer dielectric elastomer tubular actuator (1-3), two check valves (1-1), two straight-through pagoda water pipe joints (1-2), a fifth guide pipe, and a sixth guide pipe. The two straight-through pagoda water pipe joints (1-2) are respectively connected to the two ends of the central multilayer dielectric elastomer tubular actuator (1-3). One end of each straight-through pagoda water pipe joint (1-2) is connected to the central multilayer dielectric elastomer tubular actuator (1-3), and the other end is connected to the corresponding check valve (1-1) through the fifth guide pipe / sixth guide pipe. The two ends of the central multilayer dielectric elastomer tubular actuator (1-3) are connected. Under the action of the two check valves (1-1), the water inside the flexible hydraulic pump (1) flows from the bionic fish tail structure (8) to the hydraulic flexible gripper (2).

3. The underwater swimming robot based on a dielectric elastomer according to claim 1, characterized in that: The hydraulic flexible gripper (2) includes two symmetrically arranged hydraulic flexible actuators (2-1) and a four-way valve (2-2); the four-way valve (2-2) has four valve ports, two of which are used to connect the two symmetrically arranged "V" hydraulic flexible actuators (2-1) respectively, and the remaining two valve ports are used as the water inlet and water outlet of the hydraulic flexible gripper (2) respectively; one side of each hydraulic flexible actuator (2-1) is a deformation layer and the other side is a passive bending layer. The deformation layer consists of multiple rectangular protrusions arranged at intervals along the length direction, and the passive bending layer is a rectangular surface. The passive bending layer of each hydraulic flexible actuator (2-1) is arranged inward and the deformation layer is arranged outward.

4. The underwater swimming robot based on a dielectric elastomer according to claim 3, characterized in that: When the hydraulic flexible gripper (2) clamps, water flows into each hydraulic flexible actuator (2-1) through the corresponding valve port. The solenoid valve (7) closes, causing the outlet of the hydraulic flexible gripper (2) to close, which in turn increases the pressure inside the two hydraulic flexible actuators (2-1). This causes the deformation layer of each hydraulic flexible actuator (2-1) to bend outward. The passive bending layer is driven by the deformation layer to bend outward together. The two hydraulic flexible actuators (2-1) in the shape of "V" achieve the clamping function by bending and deforming into the shape of "O". When the hydraulic flexible gripper (2) is released, the solenoid valve (7) opens, causing the outlet of the hydraulic flexible gripper (2) to open, and water flows out from the two hydraulic flexible actuators (2-1), thereby releasing the pressure inside the two hydraulic flexible actuators (2-1). The two hydraulic flexible actuators (2-1) that are in the shape of "O" return to the shape of "V", thus realizing the release function.

5. The underwater swimming robot based on a dielectric elastomer according to claim 2, characterized in that: The biomimetic fish tail structure (8) includes two tail-end multilayer dielectric elastomer tubular actuators (8-4), an adapter (8-1), a flexible flapping wing film (8-3), and a flexible rigid passive layer film (8-2). The two tail-end multilayer dielectric elastomer tubular actuators (8-4) are arranged in parallel at intervals, and both ends on the same side are connected to the adapter (8-1). The two tail-end multilayer dielectric elastomer tubular actuators (8-4) are connected to each other through the flexible rigid passive layer film (8-2), and the flexible rigid passive layer film (8-2) and the two tail-end multilayer dielectric elastomer tubular actuators (8-4) are arranged in parallel. The end of the flexible rigid passive layer film (8-2) away from the adapter (8-1) is Y-shaped, and the flexible flapping wing film (8-3) is arranged in a fan-shaped area formed by the two ends of the Y-shape.

6. The underwater swimming robot based on a dielectric elastomer according to claim 5, characterized in that: The middle multilayer dielectric elastomer tubular actuator (1-3) and the tail multilayer dielectric elastomer tubular actuator (8-4) both include dielectric elastomers. After voltage is applied, the dielectric elastomers can elongate and deform in both the length and radial directions from their initial state. After the voltage is removed, they can restore their deformation and return to their initial state. After the voltage is applied, the central multilayer dielectric elastomer tubular actuator (1-3) expands and deforms, and water is drawn from the external water environment into the cavity of the central multilayer dielectric elastomer tubular actuator (1-3). After the voltage is removed, it recovers its deformation and, under the action of restoring force, squeezes the water in the cavity of the central multilayer dielectric elastomer tubular actuator (1-3) into the hydraulic flexible gripper (2). The tail-end multilayer dielectric elastomer tubular actuator (8-4) is divided into two layers along the width direction, namely the first layer and the second layer. After applying voltage to the first layer / second layer, the first layer / second layer expands and deforms from the initial state, while the second layer / first layer remains in the initial state without applying voltage. This causes the tail-end multilayer dielectric elastomer tubular actuator (8-4) to bend and deform towards the second layer / first layer from the initial state, thereby driving the flexible rigid passive layer film (8-2) and the flexible flapping wing film (8-3) to bend and deform towards the second layer / first layer from the initial state. After the voltage is removed from the first / second layer, the deformation is restored to the initial state, which causes the tail multilayer dielectric elastomer tubular actuator (8-4) to restore its initial state; thereby driving the flexible rigid passive layer film (8-2) and the flexible flapping wing film (8-3) to restore their initial state.

7. The underwater swimming robot based on a dielectric elastomer according to claim 1, characterized in that: The control module includes a control circuit board (5), a boost circuit board (6), and a manual switch (9); the control circuit board (5) includes a main battery (5-1), a voltage regulator module (5-2), a main control board (5-3), and a power switch circuit (5-4); the main battery (5-1) and the manual switch (9) are electrically connected, the manual switch (9) and the voltage regulator module (5-2) are electrically connected, the voltage regulator module (5-2) and the main control board (5-3) are electrically connected, the power switch circuit (5-4) is electrically connected to the main control board (5-3), the manual switch (9) and the solenoid valve (7) respectively, the boost circuit board (6) is electrically connected to the flexible hydraulic pump (1) and the bionic fish tail structure (8) respectively, and the manual switch (9) and the boost circuit board (6) are electrically connected.

8. A driving method for an underwater robot based on a dielectric elastomer as described in any one of claims 1-7, characterized in that, The driving method is as follows: It includes a clamping method and a motion method, wherein the motion method is: S1.1: Apply voltage to a part of the bionic fish tail structure (8) through the control module, so that the bionic fish tail structure (8) bends and deforms on the basis of the basic state, bending to one side, and then remove the voltage through the control module, so that the bionic fish tail structure (8) returns to the initial state. S1.2: Repeat step S1.1, but apply voltage to a different part, so that the bionic fish tail structure (8) bends in the opposite direction to step S1.1; S1.3: Repeat steps S1.1 to S1.2, the biomimetic fish tail structure (8) generates a thrust in the direction of the hydraulic flexible gripper (2), thereby realizing the movement of the dielectric elastomer underwater robot; The clamping method is as follows: S2.1: By applying voltage to the flexible hydraulic pump (1) through the control module, water is drawn into the flexible hydraulic pump (1) from the external water environment. After removing the voltage, the water in the flexible hydraulic pump (1) is squeezed into the hydraulic flexible gripper (2). The control module controls the solenoid valve (7) to close, so that the hydraulic flexible gripper (2) bends and deforms to clamp the object from the initial state. S2.2: The solenoid valve (7) is opened by controlling the control module, so that the water in the hydraulic flexible gripper (2) flows out through the solenoid valve (7), and the object is released after restoring its initial state.

9. The driving method for an underwater robot based on a dielectric elastomer according to claim 8, characterized in that, The specific motion method is as follows: Step S1.1 is as follows: The voltage of the main battery (5-1) is boosted by the boost circuit board (6) and applied to the first / second layer of each of the two tail-end multilayer dielectric elastomer tubular actuators (8-4) of the bionic fish tail structure (8). This causes the two tail-end multilayer dielectric elastomer tubular actuators (8-4) to bend and deform in the direction of their respective second / first layer, thereby causing the flexible rigid passive layer film (8-2) and flexible flapping wing film (8-3) to bend and deform in the direction of the second / first layer from their initial state. After the voltage is removed from the first / second layer, the deformation is restored to the initial state, causing the tail-end multilayer dielectric elastomer tubular actuators (8-4) to restore their initial state. This, in turn, causes the flexible rigid passive layer film (8-2) and flexible flapping wing film (8-3) to restore their initial state. Step S1.2 specifically includes: The voltage of the main battery (5-1) is applied to the second / first layer of the two tail-end multilayer dielectric elastomer tubular actuators (8-4) of the bionic fish tail structure (8) after passing through the boost circuit board (6). The rest of the process is the same as step S1.1, so that the flexible rigid passive layer film (8-2) and the flexible flapping wing film (8-3) bend in the opposite direction to step S1.

1. Step S1.3 specifically includes: S1.3: Repeat steps S1.1 to S1.

2. The flexible flapping wing film (8-3) in the bionic fish tail structure (8) continues to bend and swing, thereby generating a forward thrust. By changing the time of the voltage applied in step S1.1 / step S1.2, the degree of bending of the flexible flapping wing film (8-3) towards the direction of step S1.1 / step S1.2 is realized, thereby realizing the movement towards the direction with a lower degree of bending.

10. The driving method for an underwater robot based on a dielectric elastomer according to claim 8, characterized in that, The clamping method is specifically as follows: Step 2.1 specifically involves: The voltage of the main battery (5-1) is boosted by the boost circuit board (6) and applied to the central multilayer dielectric elastomer tubular actuator (1-3) in the flexible hydraulic pump (1). Through expansion and deformation, the water from the external water environment flows into the cavity of the central multilayer dielectric elastomer tubular actuator (1-3) through the second guide pipe. After the voltage is removed, it recovers its deformation, and under the action of restoring force, the water in the cavity of the central multilayer dielectric elastomer tubular actuator (1-3) flows into the inlet of the four-way valve (2-2). Then, the water flows into each hydraulic flexible actuator (2-1) through the corresponding valve port. The control solenoid valve (7) is closed, which closes the outlet of the four-way valve (2-2). This increases the pressure inside the two hydraulic flexible actuators (2-1), causing the deformation layer of each hydraulic flexible actuator (2-1) to bend outward. The passive bending layer is driven by the deformation layer to bend outward together. The two hydraulic flexible actuators (2-1) in the shape of "V" are bent and deformed into the shape of "O" to clamp the object. Step 2.2 specifically involves: The control solenoid valve (7) opens the outlet of the four-way valve (2-2), and the water flows out through the outlet of the four-way valve (2-2) after passing through the respective valve ports of the two hydraulic flexible actuators (2-1). Then, it returns to the external water environment through the solenoid valve (7), thereby releasing the internal pressure of the two hydraulic flexible actuators (2-1). The two hydraulic flexible actuators (2-1) that were in the "O" shape return to the "V" shape and release the object.

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