CN111409803A - A bionic wave fin driven by IPMC - Google Patents

Abstract

The invention discloses a bionic wave fin driven by IPMC. One side of the bracket is fixed on the main body of the robotic fish, and the other side is connected to the elastic film of the imitation fin surface. The elastic film is provided with a plurality of IPMC driving pieces, each IPMC driving The slice adopts an independent control method, and swings in sequence with equal phase difference. By changing the swing phase and driving voltage of the IPMC drive slice, the motion state of the fluctuating fin is changed to make the robotic fish move in the water. The present invention has a simple and lightweight structure, can imitate the motion of fishes propelled by waves in the MPF mode, and has higher flexibility, maneuverability, concealment and propulsion energy efficiency than the traditional driving mode.

Description

A bionic wave fin driven by IPMC

technical field

The invention belongs to the technical field of bionic robotic fish driving, in particular to a bionic wave fin driven by IPMC.

Background technique

After hundreds of millions of years of evolution, fish have evolved extraordinary motor skills. So far, it is difficult for artificial vehicles to achieve the swimming efficiency of fish. Inspired by the way of fish propulsion, underwater bionic propulsion robots have gradually attracted the attention of researchers. Researchers have tried to improve the comprehensive performance of underwater vehicles by simulating the motion mechanism of fish. However, traditional fish-like robots mostly use rigid motors in series to drive, so that they can only achieve "similar shape" in simulating fish movement, and their propulsion efficiency is far lower than that of real fish.

In recent years, with the continuous development of smart materials such as Shape Memory Alloy (SMA), Ionic Polymer Mental Composite (IPMC), and Piezoelectric Ceramics (Principle of lead Zirconate Titanate, PZT) The bionic robotic fish drive mechanism provides a new idea. Among them, IPMC materials are expected to become a new generation of underwater actuator materials by virtue of the advantages of integrating sensing, driving, energy harvesting and other functions. IPMC is an ionic electroactive polymer (Electroactive Polymer, EAP) material, its main body is a polymer film, and thin precious metal electrodes are plated on both sides of the film. Under the action of the applied voltage, the IPMC bends and deforms in the direction of the anode. Compared with the traditional motor drive, the IPMC is used as the bionic robotic fish driver, which has the advantages of low energy consumption, long battery life, good continuous flexibility, noiseless movement, and environmental friendliness.

At present, researchers at home and abroad have done some research and exploration on IPMC-driven bionic robotic fish. However, most of the fish imitate the caudal fin swing drive, body wave drive in the BCF model, and the pectoral fin swing drive in the MPF model, while few fish imitate the propulsion by the wave fin in the MPF model. The MPF propulsion mode bionic robotic fish has better propulsion efficiency, maneuverability and stability under low-speed swimming, and is more suitable for underwater survey and reconnaissance operations. Among them, the pectoral fin wave propulsion bionic robotic fish has excellent swimming performance. It has become an emerging hot spot in the field of bionic robotic fish research.

Therefore, it is imperative to develop an IPMC-driven bionic undulating fin that can mimic the undulating propulsion of fish in MPF mode.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a bionic wave fin driven by IPMC based on the deficiencies in the prior art. The bionic wave fin uses IPMC as a driver and can imitate the wave propulsion of black devil fish in nature. The independent driving method is adopted to improve the degree of freedom and maneuverability of the wave fin; the sandwich structure is adopted to improve the overall rigidity of the wave fin, so as to achieve a "rigid-flexible combination".

The present invention adopts following technical scheme:

A bionic wave fin driven by IPMC, comprising a bracket, one side of the bracket is fixed on the main body of the robotic fish, and the other side is connected to an elastic film of the imitation fin surface, the elastic film is provided with a plurality of IPMC driving pieces, each IPMC driving piece The independent control method is adopted to oscillate in turn with equal phase difference, and the motion state of the oscillating fin is changed by changing the swing phase and driving voltage of the IPMC driving piece to make the robotic fish move in the water.

Specifically, electrodes are respectively provided on the upper and lower surfaces of the IPMC driving piece close to one end of the bracket, the electrodes are connected to the IPMC driving piece, and the IPMC driving piece is powered by an external power source through a waterproof conduit.

Specifically, a plurality of IPMC driving pieces are embedded on the elastic film at intervals in sequence.

Further, the IPMC driver slices include eight and are equally spaced.

Specifically, the elastic film is made of polydimethylsiloxane material.

Specifically, the propagating direction of the wave fin sine wave is controlled to control the forward or backward motion of the robotic fish. When the phase of the front IPMC driving piece is ahead of the rear IPMC driving piece, the robotic fish moves forward; the phase of the front IPMC driving piece When lagging behind the IPMC driving piece, the robotic fish moves backward; when the sine wave propagation speed of the wave fins on both sides is inconsistent, the robotic fish completes the steering action.

Further, when the voltage on the IPMC driving sheet of the left wave fin of the robotic fish is lower than the voltage on the IPMC driving sheet of the right wave fin of the robotic fish, the robotic fish performs a left turn; when the voltage on the IPMC driving sheet of the left wave fin of the robotic fish is greater than that on the right When the voltage on the IPMC drive sheet in the side wave fin, the robotic fish performs a right-turn motion.

Compared with the prior art, the present invention at least has the following beneficial effects:

The present invention is a bionic wave fin driven by IPMC, which adopts intelligent material IPMC instead of traditional motor or steering gear as the drive, saves the complicated and bulky mechanical transmission mechanism, makes the wave fin more flexible and continuous, and has a simpler structure Lightweight; the IPMC driving pieces in the wave fins are independent of each other, and each IPMC driving piece can be controlled individually, and then the long fins of the robotic fish can be driven to generate various modes of traveling waves, with good maneuverability; wave fins Built on the IPMC drive, the metal concentration is low, it is difficult to detect it by metal detectors or radar, and the concealment is high.

Further, the electrodes are adhered to the upper and lower surfaces of the IPMC drive piece close to the bracket side, and the IPMC drive piece is powered by an external power source through the waterproof conduit; by controlling the voltage signal applied to the IPMC drive piece, the IPMC drive piece is bent. Deformation, thereby driving the wave fins to move in the water.

Furthermore, the IPMC driving pieces are distributed equidistantly in the elastic film imitating the fin surface. The design of the two simulates the fin rays and fin membranes in the wave fin of the black devil fish in nature, and can simulate the wave fin of the black devil fish to generate waves. sports.

Further, using the intelligent material IPMC as the driving device of the robotic fish, compared with the traditional driving method, the driving voltage is small, the energy conversion rate is high, the energy consumption is small, the battery life is long, the noise generated is small, and the interference to the environment is small;

To sum up, the present invention has a simple and lightweight structure, can imitate the motion of fishes propelled by waves in the MPF mode, and has higher flexibility, maneuverability, concealment and propulsion energy efficiency than the traditional driving method.

The technical solutions of the present invention will be further described in detail below through the accompanying drawings and embodiments.

Description of drawings

1 is a schematic structural diagram of a bionic wave fin of the present invention;

Figure 2 is a schematic diagram of the arrangement of the IPMC driver chips inside the bionic wave fin;

3 is a schematic diagram of the manufacturing process of the bionic wave fin;

Figure 4 is a schematic diagram of the motion state of the bionic wave fin;

Fig. 5 is the driving signal when the robotic fish moves forward;

Fig. 6 is the driving signal when the robotic fish retreats.

Among them: 1. bracket; 2. electrode; 3. IPMC driving sheet; 4. elastic film.

Detailed ways

In the description of the present invention, it should be understood that the terms "center", "portrait", "horizontal", "top", "bottom", "front", "rear", "left", "right", " The orientation or positional relationship indicated by "vertical", "horizontal", "top", "bottom", "inside", "outside", "one side", "one end", "one side", etc. The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Also, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, unless otherwise expressly specified and limited, for example, it may be a fixed connection or a detachable connection Connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

The invention provides a bionic wave fin driven by IPMC. An acrylic bracket is used to connect the main body of the robotic fish and the wave fin driving system. Eight IPMC driving pieces are equidistantly distributed on the elastic film of the imitation fin surface. Appropriate driving voltage signals can make the bionic robotic fish generate linear cruising (including forward and backward), left/right turns and other movements in the water. As a driving device of the bionic robotic fish, the invention can increase the flexibility and endurance of the robotic fish, reduce its motion noise, improve the concealment, and has wide application prospects.

Please refer to FIG. 1 and FIG. 2 , an IPMC-driven bionic wave fin of the present invention includes a bracket 1 , an electrode 2 , an IPMC driving piece 3 and a fin-like elastic film 4 .

The bracket 1 is an acrylic bracket, one side is fixed on the main body of the robotic fish, and the other side is connected to the IPMC driving piece 3 and the elastic film 4 imitating the fin surface, which plays a transition role for the main body of the robotic fish and the wave fin driving system.

Electrode 2 is a metal electrode, made of gold foil, bonded to the edge of the surface of the IPMC drive piece, as the lead-out electrode on the upper and lower surfaces of the IPMC drive piece, and powered by an external power source through a waterproof conduit to supply power to the IPMC drive piece 3.

An electrode 2 is respectively bonded to the upper and lower surfaces of the IPMC driving sheet 3 near one end of the bracket 1, and the other end is embedded in the elastic film 4 of the imitation fin surface; the elastic film 4 of the imitation fin surface is glued with eight IPMC driving sheets at intervals in sequence. 3, IPMC driver slice 3-1, IPMC driver slice 3-2, IPMC driver slice 3-3, IPMC driver slice 3-4, IPMC driver slice 3-5, IPMC driver slice 3-6, IPMC driver slice 3 -7 and IPMC drive slices 3-8, eight IPMC drive slices 3 are equally spaced, as shown in Figure 2.

The fin-like elastic film 4 is made of polydimethylsiloxane (PDMS) material. The fabrication process is simple and fast, the material cost is low, and it is optically transparent, has good biocompatibility, and is easily compatible with various materials at room temperature. Bonding, high elasticity of the structure due to low Young's modulus, etc. The schematic diagram of the arrangement of the IPMC driver chip inside the bionic wave fin is shown in Figure 2.

Referring to Figure 4, the motion of the bionic wave fin is:

Each IPMC driving piece 3 adopts an independent control method and cooperates with each other; under the drive and control of the external power source, a series of IPMC driving pieces 3 swing in sequence with equal phase difference, and the adjacent IPMC driving pieces 3 are in the swing process except for Except for a fixed phase difference, other motion parameters (maximum swing angle, swing frequency) are the same, and then the wave fin is controlled to generate a series of sine traveling waves. The carrier moves in the opposite direction. According to the principle of conservation of momentum, the fin surface will receive a thrust; by changing the parameters such as the swing phase and driving voltage of the IPMC drive plate 3, the robotic fish can be made to roam in a straight line in the water (including forward and backward), Movements such as left/right turns.

Please refer to Figure 3, the manufacturing method of the bionic wave fin specifically includes the following steps:

S1. Prepare IPMC actuator;

The manufacturing process of IPMC material includes four steps: pretreatment of base film, immersion reduction, electroless plating, and material post-treatment. The prepared IPMC material is cut into rectangular strips as actuators for bionic wave fins.

S2. Use a CNC rapid milling machine to cast two bionic wave fins for accommodating IPMC actuators and PDMS films;

The size of the two molds is the same, and the length and width are consistent with the designed wave fins; the distance between the 8 equally spaced grooves is the same as that of the designed 8 IPMC driving pieces in the elastic film imitating the fin surface, and the depth is the same. It is half of the thickness of the IPMC driver.

S3. Prepare PDMS gel, and evenly spread the PDMS gel as the upper and lower encapsulation membranes; place the IPMC driver sheets on the lower encapsulation membrane at intervals, so that the lower surface of the IPMC driver sheet is bonded to the PDMS glue, and the upper encapsulation membrane Cover the IPMC driver sheet, apply even pressure to make the PDMS glue and the IPMC driver sheet bond evenly, then clamp it with a mold, and cure it at room temperature;

S4, removing the mold to obtain a bionic wave fin.

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Please refer to Figure 5 and Figure 6, the realization of the linear cruising motion of the robotic fish, under the stimulation of the electrical signal, the adjacent IPMC driving pieces 3 on both sides of the robotic fish swing in sequence with the same frequency and equal phase difference, driving the elasticity of the imitation fin surface The membrane 4 generates a series of sinusoidal fluctuations, which generate a thrust to push the fish body.

By controlling the propagation direction of the wave fin sine wave, the robotic fish can be controlled to move forward or backward. If the phase of the front IPMC driving piece is ahead of that of the back, the robotic fish will move forward; on the contrary, if the phase of the current IPMC driving piece is behind the back, the robotic fish will move forward. back.

The driving signal adopts a square wave, and the driving signal when moving forward is shown in Figure 5, and the driving signal when moving backward is shown in Figure 6.

The realization of the left/right turning motion of the robotic fish, when the sine wave propagation speed of the wave fins on both sides is inconsistent, the robotic fish can complete the turning action.

When turning left, the voltage applied to the left wave fin IPMC driving piece is controlled to be smaller than the voltage applied to the right wave fin IPMC driving piece.

When turning right, the voltage applied to the IPMC driving piece of the left wave fin is controlled to be greater than the voltage applied to the IPMC driving piece of the right wave fin.

Due to the different movement amplitudes of the wave fins on both sides, different thrusts are generated, and the thrust on the right side is larger/smaller than that on the left side, causing the robotic fish to deflect left/right as a whole. The greater the difference between the voltage applied on the left wave fin IPMC driving piece and the voltage applied on the right wave fin IPMC driving piece, the greater the turning range and speed of the robotic fish.

Among them, when the sine waves of the wave fins on both sides propagate in opposite directions, the robotic fish can complete the fastest turning. Taking left turn as an example, when the phase of the IPMC driver in front of the right wave fin is ahead of that of the rear, and the phase of the IPMC driver in front of the left wave fin lags behind, that is, the right wave fin adopts the driving signal shown in Figure 5, and the left wave fin adopts the driving signal shown in Fig. When the side wave fin adopts the driving signal shown in Figure 6, the robotic fish turns left; during the forward or turning process, the voltage applied to the IPMC driving piece 3 should be within a reasonable voltage range.

The invention obtains inspiration from the efficient wave propulsion mode of the black devil fish in nature, and provides a wave fin propulsion device that can be applied to a bionic robotic fish. Using a structure in which multiple IPMC drivers are equidistantly distributed in the elastic film of the imitation fin surface, the fin rays and fin films in the wave fin of the black devil fish are simulated, and independent driving voltage signals are applied to each IPMC driver to make it fit Swing, and then realize the wave propulsion of the bionic wave fin. Using intelligent material IPMC instead of traditional motor or steering gear as the drive, eliminating the need for complex and bulky mechanical transmission mechanisms, making the wave fin structure simpler and lighter, realizing the flexible drive of the bionic robotic fish, making its movement more flexible and continuous , which better realizes the imitation of the real black devil fish.

To sum up, the bionic wave fin based on IPMC drive of the present invention has a simple and lightweight structure, and can imitate the movement of fish propelled by wave in MPF mode. Compared with the traditional driving method, the driving voltage is small, the energy conversion rate is high, and the energy Low power consumption, long battery life, low noise generation, low environmental interference, and higher flexibility, mobility, concealment and propulsion energy efficiency.

The above content is only to illustrate the technical idea of the present invention, and cannot limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention all fall within the scope of the claims of the present invention. within the scope of protection.

Claims (7)

1. a bionic wave fin based on IPMC drive, is characterized in that, comprises support (1), one side of support (1) is fixed on the robot fish main body, and the other side connects the elastic film (4) of imitation fin surface, The elastic film (4) is provided with a plurality of IPMC driving pieces (3), and each IPMC driving piece (3) adopts an independent control mode and swings in turn with equal phase difference, and by changing the swing phase and driving voltage of the IPMC driving piece (3) Change the motion state of the wave fin to make the robot fish move in the water. 2. The bionic wave fin based on IPMC drive according to claim 1, wherein the upper and lower surfaces of the IPMC drive sheet (3) close to one end of the bracket (1) are respectively provided with electrodes (2), the electrodes (2) and the IPMC The driving piece (3) is connected, and the IPMC driving piece (3) is powered by an external power source through a waterproof conduit. 3. The IPMC-driven bionic wave fin according to claim 1 or 2, characterized in that, a plurality of IPMC driving pieces (3) are embedded in the elastic film (4) at intervals in sequence. 4 . The IPMC-driven bionic wave fin according to claim 3 , wherein the IPMC driving pieces ( 3 ) include eight and are equally spaced. 5 . 5 . The IPMC-driven bionic wave fin according to claim 1 , wherein the elastic film ( 4 ) is made of polydimethylsiloxane material. 6 . 6. the bionic wave fin based on IPMC drive according to claim 1, is characterized in that, control the propagation direction of wave fin sine wave realizes the forward or backward movement of control robot fish, and the phase of the current IPMC driving piece is ahead of the rear. When the IPMC drive piece, the robotic fish moves forward; when the phase of the front IPMC drive piece lags behind the rear IPMC drive piece, the robotic fish moves backward; when the sine wave propagation speed of the wave fins on both sides is inconsistent, the robotic fish completes the steering action . 7. The bionic wave fin based on IPMC drive according to claim 6, is characterized in that, when the voltage on the left side wave fin IPMC driving sheet of the robotic fish is less than the voltage on the right side wave fin IPMC driving sheet of the robotic fish, the robotic fish carries out Left-turn movement; when the voltage on the IPMC driving piece of the left wave fin of the robotic fish is greater than the voltage on the IPMC driving piece of the right wave fin, the robotic fish will turn right.

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