An amphibious bionic robotic fish

Abstract

The application discloses an amphibious bionic machine fish, and belongs to the technical field of bionic robots, and specifically comprises a head, an abdomen and a tail fin which are sequentially hinged; a driving device is arranged in the abdomen and connected with the head and the tail fin, and can move the head and the tail fin around the hinge; a pectoral fin part is installed on the head and can generate friction with the ground, and realizes crawling operation in the process of swinging the head; through the structural arrangement of the driving device, the machine fish can realize full-body periodic fluctuation, can make swimming action, and thus can move in water; through the arrangement of the pectoral fin part, the machine fish can move on land, realizes amphibious motion, and improves the motion performance of the machine fish.

Description

Technical Field

[0001] This invention belongs to the field of biomimetic robot technology, specifically relating to an amphibious biomimetic robotic fish. Background Technology

[0002] Amphibious robots can adapt to complex operating environments in water, land, and transitional zones, and have broad application prospects and significant practical value in fields such as underwater target tracking, near-shore reconnaissance, dam inspection, ecological monitoring, and aquaculture. In recent years, with the rapid development of robotics technology, researchers have proposed various amphibious robot design schemes. Existing amphibious robots can be mainly divided into two categories.

[0003] The first category consists of engineered amphibious platforms, which often employ legged structures, wheel-leg hybrid structures, or fin-propeller hybrid structures. For example, patent applications CN121671235A and CN122008728A disclose underwater robots based on propeller propulsion. These robots need to transform into wheeled mechanisms in terrestrial environments to achieve ground movement. However, such engineered platforms have significant technical drawbacks: on the one hand, propeller propulsion generates considerable noise and turbulence underwater, resulting in poor stealth and hindering covert operations such as underwater reconnaissance and ecological monitoring.

[0004] The second category is biomimetic amphibious platforms, which are designed to mimic the shape, structure, and movement of amphibians such as sea turtles, salamanders, and mudskippers. For example, patent application CN120802965A discloses a sea turtle-inspired robot that uses multiple three-degree-of-freedom flippers for underwater propulsion and land walking. However, these biomimetic platforms typically require complex multi-degree-of-freedom drive mechanisms and sophisticated control algorithms to switch between different movement modes, making control difficult and resulting in performance that is hard to achieve in practical applications, hindering efficient and stable amphibious movement. Summary of the Invention

[0005] The purpose of this invention is to provide an amphibious biomimetic robotic fish that can reduce noise and improve movement performance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an amphibious biomimetic robotic fish, comprising a head, abdomen, and tail fin, which are hinged together in sequence; a line drive device is disposed inside the abdomen and connected to the head and tail fin, enabling the head and tail fin to move around the hinge; the pectoral fin is mounted on the head and can generate friction with the bottom surface, enabling crawling operations during the head swinging process. The line drive device includes a drive assembly, a head rope, and a tail fin rope. The drive assembly provides power for the movement of the head and tail fin. One end of the head rope is connected to the head, and the other end is connected to the drive assembly. One end of the tail fin rope is connected to the tail fin, and the other end is connected to the drive assembly. When the drive assembly is working, it enables the head and tail fin to move. The drive assembly includes two side drive assemblies, an intermediate drive assembly, and a waterproof motor. There are two side drive assemblies, and the two side drive assemblies can rotate synchronously in opposite directions. Each side drive assembly is connected to the head rope and the tail fin rope. The intermediate drive assembly is connected to the side drive assemblies. The waterproof motor is used to rotate the intermediate drive assembly, and during the rotation of the intermediate drive assembly, the two side drive assemblies alternately perform rope winding and unwinding actions.

[0007] Furthermore, there are two head cables and two tail fin cables. The two head cables are connected to the two side transmission components one by one, and the two tail fin cables are connected to the two side transmission components one by one. Both head cables and two tail fin cables are in a taut state.

[0008] Furthermore, the lateral transmission assembly includes a central shaft, a head reel, and a tail fin reel. The central shaft is connected to the abdomen and can rotate. The head reel is fixed on the central shaft, so that the head rope is wound around the head reel. The tail fin reel is fixed on the central shaft, so that the tail fin rope is wound around the tail fin reel. When the central shaft rotates, the head reel and the tail fin reel synchronously perform rope winding or unwinding actions.

[0009] Furthermore, the side transmission assembly also includes an upper gear and a lower gear, both of which are mounted on the central shaft and can mesh with the intermediate transmission assembly.

[0010] Furthermore, the intermediate transmission assembly includes an incomplete gear and a transmission gear set. The incomplete gear is connected to the output shaft of the waterproof motor and can mesh with the upper gear on one of the side transmission assemblies during rotation. The transmission gear set is located between the two side transmission assemblies and can mesh with the lower gears on the two side transmission assemblies, causing the two side transmission assemblies to rotate in opposite directions.

[0011] Furthermore, the transmission gear set includes two intermediate gears, which mesh with each other and correspond one-to-one with the bottom gears on the two side transmission components.

[0012] Furthermore, the pectoral fin includes a pectoral fin base plate and climbing claws. The pectoral fin base plate is located below the head and is rotatable. There are several climbing claws, all of which are set on the pectoral fin base plate and arranged in a fan shape around the rotation center of the pectoral fin base plate, forming a climbing claw assembly that is symmetrically arranged on the pectoral fin base plate.

[0013] Furthermore, the climbing claw includes a silicone pad and an inclined steel pin. The silicone pad is elongated and fixed to the pectoral fin substrate. The inclined steel pin is fixed to the silicone pad and forms an acute angle with the surface of the pectoral fin substrate.

[0014] On the other hand, it also includes the pelvic fins, which are located below the abdomen and are capable of rotation.

[0015] Furthermore, the pelvic fins have the same structure as the pectoral fins, and the two can work together to enable the robotic fish to crawl.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention enables the robotic fish to achieve periodic undulations throughout its body through the structural design of the drive device, allowing the robotic fish to make swimming movements and thus move in the water. At the same time, through the design of the pectoral fins, the robotic fish can move on land, achieving not only amphibious movement, but also, when moving on land, only the line drive device needs to be activated to drive the head and tail fins to move, thereby driving the pectoral fins to move. Since the pectoral fins can generate friction with the ground, the robotic fish can crawl on the ground. The robotic fish can move in water and on land without the need for sophisticated control algorithms, thus improving the robotic fish's movement performance. In addition, since the robotic fish moves in the water by using a wire-driven device to move the head and tail fin, the traditional propeller component is eliminated, which can significantly reduce noise. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of the drive device structure of the present invention; Figure 4 This is a schematic diagram of the meshing state between the incomplete gear and the upper gear of the present invention; Figure 5 This is a schematic diagram of the pectoral fin structure of the present invention; Figure 6 This is a schematic diagram of the ventral fin structure of the present invention; Figure 7 This is a microscopic observation image of the steel needle of the present invention; Figure 8 This is a schematic diagram of the whole-body wave motion driven by the present invention; Among them, 100-head; 101-head shell; 102-head air chamber; 103-first drive servo; 104-head cable; 105-head body; 200-abdomen; 201-abdomen shell; 202-abdomen air chamber; 203-waterproof motor; 204-second drive servo; 205-tail fin cable; 206-abdomen body; 300-pectoral fin; 301-pectoral fin substrate; 302-pectoral fin silicone. Pad; 303-Pectoral fin inclined steel needle; 304-Pectoral fin rudder disc; 400-Pelvic fin; 401-Pelvic fin base plate; 402-Pelvic fin silicone pad; 403-Pelvic fin inclined steel needle; 404-Pelvic fin rudder disc; 500-Caudal fin; 601-Central shaft; 602-Caudal fin reel; 603-Head reel; 604-Upper gear; 605-Lower gear; 606-Central shaft column; 607-Incomplete gear; 608-Intermediate gear. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] See Figure 1 As shown, the present invention provides an amphibious biomimetic robotic fish inspired by the rock loach. The overall dimensions of the robotic fish are 300mm in length, 125mm in maximum width, and 83mm in height. It is mainly composed of three parts: head 100, abdomen 200, and tail fin 500.

[0021] See Figure 1 As shown, the overall shape of the robotic fish mimics that of a rock loach, specifically featuring a streamlined top and a flat bottom, comprising multiple body segments connected sequentially along the axial direction. The head 100 and abdomen 200 are hinged together, and the rear end of the abdomen 200 is hinged to the tail fin 500. Furthermore, the joints constituting the tail fin 500 are sequentially connected by hinges, allowing the robotic fish's body to continuously bend and deform under driving action.

[0022] See Figure 1 and Figure 2 As shown, the head 100 includes a head shell 101, a head air chamber 102, and a head body 105. The head shell 101 is made of PLA material through 3D printing. PLA material in this technical solution is an existing multifunctional bioplastic with environmentally friendly and biodegradable characteristics. The surface of the head shell 101 is smooth and streamlined, which can effectively reduce the fluid resistance of the robotic fish when swimming underwater. The head air chamber 102 is a sealed cavity structure filled with air to provide buoyancy support for the robotic fish.

[0023] See Figure 1 and Figure 2 As shown, the abdomen 200 includes an abdominal shell 201, an abdominal air chamber 202, and an abdominal body 206. The bottom of the abdominal body 206 has a flat structure to ensure sufficient support stability and low frictional resistance when the robotic fish crawls on land. The abdominal shell 201 is mounted on the abdominal body 206, and a storage area is formed between the two. The abdominal air chamber 202 is located in this storage area. The abdominal air chamber 202 is also a sealed cavity structure, which is filled with air. It works in conjunction with the head air chamber 102 to provide buoyancy for the entire machine in water.

[0024] See Figure 1 and Figure 2 As shown, the line drive device is the core drive mechanism for realizing the periodic oscillation of the robotic fish's body in this invention. It is mainly used to make the head and tail fin swing. The line drive device consists of a drive component, a head rope 104, and a tail fin rope. The drive component is set inside the abdomen 200. The drive component is connected to the head shell 101 through the head rope 104 and to the tail fin 500 through the tail fin rope 205. When the drive component starts to work, it realizes transmission through the head rope 104 and the tail fin rope 205, making the head and tail fin swing.

[0025] Specifically, see Figure 2 and Figure 3 As shown, the drive assembly mainly includes a waterproof motor 203, an intermediate transmission assembly, and two side transmission assemblies. The two side transmission assemblies are the first side transmission assembly and the second side transmission assembly, respectively. The head cord 104 is connected to the two side transmission assemblies, and the tail fin cord 205 is also connected to the two side transmission assemblies. The output shaft of the waterproof motor 203 is connected to the intermediate transmission assembly, and the intermediate transmission assembly is simultaneously connected to the two side transmission assemblies. Thus, when the waterproof motor 203 starts working, the two side transmission assemblies rotate simultaneously, thereby causing the head 100 and tail fin 500 to swing.

[0026] In this example, there are two head cords 104. One end of one head cord 104 is fixed to the head shell 101, and the other end is wrapped around the first side transmission component and fixed to the first side transmission component. The other head cord 104 is connected to the head shell 101 and the second side transmission component in the same way. Both head cords 104 are in a taut state. During the swinging of the head 100, one side transmission component performs a cord retraction action, while the other side transmission component performs a cord release action. There are also two caudal fin ropes 205. One end of one caudal fin rope 205 is connected to the caudal fin 500, and the other end is wrapped around the first lateral transmission component and fixed to the first lateral transmission component. The other caudal fin rope 205 is connected to the caudal fin 500 and the second lateral transmission component in the same way. Both caudal fin ropes 205 are in a taut state. When the head 100 swings, the caudal fin 500 starts to swing at the same time. At this time, one lateral transmission component performs a rope-retracting action, while the other lateral transmission component performs a rope-releasing action. In this example, the two lateral transmission components have identical structures and are both 3D printed integral structures. Both include a central shaft 601 that runs through the abdominal body 206. A tail fin coil 602, a head coil 603, an upper gear 604, and a lower gear 605 are mounted on the central shaft 601, arranged sequentially from top to bottom. The upper gear 604 and the lower gear 605 both have a module of 1 and 10 teeth. The tail fin coil 602, head coil 603, and upper gear 604 are all positioned above the abdominal body 206, while the lower gear 605 is positioned below it. The intermediate transmission component includes a central shaft 606, an incomplete gear 607, and two intermediate gears 608, which are meshed together. Both intermediate gears 608 are connected to the abdominal body 206 via shafts and are located below the abdominal body 206, thus forming a transmission gear. The transmission gear set meshes with the bottom gear 605 on the two side transmission components, meaning the transmission gear set enables the two side transmission components to rotate simultaneously. The incomplete gear 607 is located above the abdominal body 206. Both the incomplete gear 607 and the transmission gear set are located between the two side transmission components, allowing the incomplete gear 607 to mesh with the upper gear on one of the side transmission components. In other words, the incomplete gear 607 can form a connection with one of the side transmission components. When the waterproof motor 203 rotates, the incomplete gear 607 alternately meshes with the upper gear 604 on the two side transmission components, enabling the side transmission component meshed with it to rotate. However, since the two side transmission components are connected by the transmission gear set, and the two transmission gear sets are composed of two intermediate gears 608 meshing with each other, the two side transmission components rotate in opposite directions, causing one side transmission component to perform a rope-retracting action while the other side transmission component performs a rope-releasing action.

[0027] However, it should be noted that the aforementioned central column is connected to the output shaft of the waterproof motor 203, so that the central column, the incomplete gear 607 and the output shaft of the waterproof motor 203 are in a coaxial state. When the waterproof motor 203 starts to work, it can make the incomplete gear 607 rotate and move. At this time, a positioning frame can also be set on the abdominal body 206 to connect the waterproof motor 203 to the positioning frame, so that there is a certain longitudinal distance between the waterproof motor 203 and the abdominal body 206.

[0028] See Figure 3 and Figure 4As shown, the working principle of the wire drive device is as follows: When the waterproof motor 203 drives the incomplete gear 607 to rotate clockwise, the incomplete gear 607 first meshes with the upper gear of the first side transmission component, driving the first side transmission component to rotate counterclockwise. The bottom gear of the first side transmission component transmits power to the bottom gear of the second side transmission component through two intermediate gears 608, causing the second side transmission component to rotate clockwise synchronously. At this time, the first side transmission component releases the wire it is wound, and the second side transmission component synchronously contracts the wire it is wound, with the release and contraction amounts being equal, ensuring that the head wire 104 and the tail fin wire 205 are always taut, thereby driving the head 100 and tail fin 500 to swing to the right. When the incomplete gear 607 continues to rotate until it meshes with the upper gear of the second side transmission component, the power transmission direction is reversed, the first side transmission component rotates clockwise, and the second side transmission component rotates counterclockwise, driving the head 100 and tail fin 500 to swing to the left. Thus, when the incomplete gear 607 rotates once, the robotic fish completes a full wave cycle, and the wave frequency of the robotic fish is equal to the rotational speed of the waterproof motor 203.

[0029] See Figure 1 , Figure 2 and Figure 8 As shown, the caudal fin 500 comprises several joint components, which are connected sequentially by hinges, arranged in a fish-scale pattern towards the rear. The initial joint component of the caudal fin 500 is fixed to the rear end of the abdomen 200, while the caudal fin cord passes through several joint components, with the end of the cord fixedly connected to the terminal joint component. In this multi-joint component series structure, when the caudal fin cord 205 is pulled, the caudal fin 500 can bend, thus more realistically simulating the wave-like propulsion of fish.

[0030] Based on the above technical solution, a pectoral fin 300 can be installed on the head 100 and an pelvic fin 400 can be installed on the abdomen 200. The pectoral fin 300 and the pelvic fin 400 are mainly used to enable the robotic fish to perform crawling movements, that is, both the pectoral fin 300 and the pelvic fin 400 are crawling parts. For details, please refer to Figures 5 to 7As shown, the pectoral fin portion 300 and the pelvic fin portion 400 have the same structural design. Taking the pectoral fin portion 300 as an example, it includes a pectoral fin base plate 301, a pectoral fin silicone pad 302, multiple rows of pectoral fin inclined steel needles 303, and a pectoral fin rudder disc 304. The pectoral fin base plate 301 is a circular PLA plate. The pectoral fin silicone pad 302 is made of 0-degree silicone material and is fixed to the pectoral fin rudder disc 304 with waterproof adhesive, or it can be fixed to the surface of the base plate 301. The pectoral fin inclined steel needles 303 are made of stainless steel, with a length of 15mm, a diameter of 0.2mm, and a needle tip diameter of approximately 25μm. The spacing between the pectoral fin steel needles in each row is 5mm, and 5-8 rows of steel needles are arranged on each side. The pectoral fin steel needles 303 are inserted into the pectoral fin silicone pads 302 for fixation, and the pectoral fin steel needles 303 are inclined at a 60° angle to the surface of the pectoral fin base plate 301. At this time, the pectoral fin silicone pads 302 and the pectoral fin steel needles 303 form a climbing claw, which is arranged in a fan shape around the rotation center of the pectoral fin base plate 301, so that a climbing claw assembly is formed on the pectoral fin base plate 301. The structure of the pelvic fin part 400 is exactly the same as that of the pectoral fin part 300, which includes the pelvic fin base plate 401, the pelvic fin silicone pads 402, and multiple rows of pelvic fins. The inclined steel needles 403 and the ventral fin rudder disk 404, the ventral fin silicone pad 402 and the multiple rows of ventral fin inclined steel needles 403 also form the climbing claw assembly. The ventral fin base plate 401 has the same structure as the pectoral fin base plate 301, the ventral fin silicone pad 402 has the same structure as the pectoral fin silicone pad 302, the ventral fin inclined steel needles 403 have the same structure as the pectoral fin inclined steel needles 303, and the ventral fin rudder disk 404 has the same structure as the pectoral fin rudder disk 304. Therefore, the structure of each component of the ventral fin part 400 will not be described in detail here.

[0031] The symmetrically distributed inclined steel needles on both sides of the pectoral fin (300) and pelvic fin (400) give the pectoral and pelvic fins anisotropic frictional characteristics tangential to the axis of rotation. Specifically, when the pectoral and pelvic fins rotate forward, the inclination direction of the steel needles is consistent with the direction of movement, resulting in a small contact area between the needle tips and the ground and low friction. When the pectoral and pelvic fins rotate backward, the inclination direction of the steel needles is opposite to the direction of movement, and the needle tips penetrate the tiny depressions in the ground, forming a mechanical interlock and significantly increasing friction. The circumferentially symmetrical arrangement of the steel needles ensures that during the rotation of the pectoral and pelvic fins, one side of the steel needles always moves in the opposite direction to the direction of movement, thereby generating a forward thrust.

[0032] To enable the pectoral fin 300 and pelvic fin 400 to rotate, a first drive servo motor 103 is installed inside the head 100. The first drive servo motor 103 is fixedly installed inside the head body 105, and its output shaft is fixedly connected to the pectoral fin servo disk 304 to drive the pectoral fin 300 to perform rotational motion.

[0033] A second drive servo motor 204 is installed inside the abdomen 200. The second drive servo motor 204 is the same model as the first drive servo motor 103 and is fixedly installed inside the abdomen body 206. Its output shaft is fixedly connected to the ventral fin rudder disk 404 and is used to drive the ventral fin 400 to perform rotational motion.

[0034] Both the first drive servo motor 103 and the second drive servo motor 204 are capable of performing bidirectional rotational drive operations, allowing the pectoral and ventral fins to rotate clockwise or counterclockwise.

[0035] The robotic fish inspired by the rock loach provided in this technical solution includes a swimming mode, a land crawling mode, and a water crawling mode. The three movement modes are described in detail below: The first movement mode is the underwater swimming mode: The waterproof motor 203 is activated, driving the incomplete gear 607 to rotate unidirectionally. The incomplete gear 607 alternately meshes with two side transmission components, causing them to alternately perform line reeling and releasing actions. This, through the head rope 104 and tail fin rope 205, drives the head 100 and tail fin 500 to produce periodic left-right oscillations. The continuous oscillations of the head 100 and the multi-jointed tail fin 500 create a wave-like propulsive motion similar to that of a fish in the water, propelling the robotic fish underwater. The operator can adjust the oscillation frequency by adjusting the speed of the waterproof motor 203, thus flexibly adjusting the swimming speed of the robotic fish.

[0036] The second movement mode is the land crawling mode: this mode includes gait forward mode and meandering forward mode. The two modes can be operated separately or in combination according to the actual terrain and work requirements.

[0037] Gait forward mode: Activating the first drive servo 103 and the second drive servo 204 drives the pectoral fin 300 and pelvic fin 400 to rotate synchronously, respectively. When the pectoral and pelvic fins rotate, the tilting direction of the inclined steel needle on one side is consistent with the direction of movement, resulting in less friction between the steel needle and the ground. The tilting direction of the inclined steel needle on the other side is opposite to the direction of movement, causing the needle tip to penetrate the ground and generate greater friction, thereby propelling the entire robotic fish forward, and the pectoral and pelvic fins slide forward smoothly. Alternatively, by controlling the speed difference between the first drive servo 103 and the second drive servo 204, different propulsive forces can be generated by the pectoral and pelvic fins, enabling the robotic fish to turn left and right.

[0038] As can be seen from the above movement patterns, both the pectoral fin 300 and the pelvic fin 400 can enable the robotic fish to crawl, but the crawling efficiency is better when the two work together.

[0039] Winding Forward Mode: Only the waterproof motor 203 is activated, while the first drive servo 103 and the second drive servo 204 are deactivated. The waterproof motor 203 drives the head 100 and tail fin 500 to undulate periodically via a wire drive device. The robotic fish's body twists left and right in the horizontal plane, utilizing the unidirectional friction between the pectoral fins 300 and pelvic fins 400 and the ground contact side to convert body undulations into forward propulsion, thus achieving winding forward movement. This mode requires only one motor, has low energy consumption, and is suitable for long-distance cruising and energy-constrained operational scenarios.

[0040] The third movement mode is the underwater crawling mode: In practical applications, the waterproof motor 203, the first drive servo motor 103, and the second drive servo motor 204 can be activated simultaneously, combining body undulation propulsion with pectoral and ventral fin gait propulsion to further enhance the robotic fish's crawling speed and climbing ability. Tests have shown that in the superimposed mode, the robotic fish can stably climb slopes and adapt to various complex ground surfaces such as rocks, concrete, and grass.

[0041] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An amphibious biomimetic robotic fish, characterized in that, include: The head (100), abdomen (200), and tail fin (500) are hinged together in sequence; A line drive device, located inside the abdomen (200) and connected to the head (100) and tail fin (500), enables the head (100) and tail fin (500) to move around the hinge. The pectoral fin (300) is mounted on the head (100) and can contact the ground and generate friction, so that the robotic fish moves as the head (100) swings. The line drive device includes: A drive assembly that provides power for the movement of the head (100) and tail fin (500); The head cord (104) is connected at one end to the head (100) and at the other end to the drive assembly; The tail fin cord (205) is connected at one end to the tail fin (500) and at the other end to the drive assembly; When the drive assembly is activated, the head (100) and tail fin (500) can be moved; The driving component includes: The lateral drive assembly consists of two lateral drive assemblies that can rotate synchronously in opposite directions. Each lateral drive assembly is connected to the head cord (104) and the tail fin cord (205). The intermediate transmission assembly is connected to the side transmission assembly; A waterproof motor is used to rotate the intermediate drive assembly, and during the rotation of the intermediate drive assembly, the two side drive assemblies alternately perform rope winding and unwinding actions.

2. The amphibious biomimetic robotic fish according to claim 1, characterized in that, There are two head ropes (104) and two tail fin ropes (205). The two head ropes (104) are connected to the two side transmission components one by one, and the two tail fin ropes (205) are connected to the two side transmission components one by one. Both the two head ropes (104) and the two tail fin ropes (205) are in a tensioned state.

3. The amphibious biomimetic robotic fish according to claim 1, characterized in that, The lateral transmission assembly includes: The central axis (601) is connected to the abdomen (200) and is rotatable; The head reel (603) is fixed on the central shaft so that the head cord (104) is wound around the head reel (603); The caudal fin coil (602) is fixed on the central shaft (601) so that the caudal fin rope (205) is wound around the caudal fin coil (602); When the central shaft (601) rotates, the head reel (603) and tail fin reel (602) synchronously perform rope winding or unwinding actions.

4. The amphibious biomimetic robotic fish according to claim 3, characterized in that, The side transmission assembly also includes an upper gear (604) and a lower gear (605), both of which are mounted on the central shaft (601) and can mesh with the intermediate transmission assembly.

5. The amphibious biomimetic robotic fish according to claim 4, characterized in that, The intermediate transmission assembly includes: An incomplete gear (607) is connected to the output shaft of a waterproof motor and can mesh with an upper gear (604) on one of the side transmission components during rotation; The transmission gear set, located between the two side transmission components, can mesh with the bottom gear (605) on the two side transmission components, causing the two side transmission components to rotate in opposite directions.

6. The amphibious biomimetic robotic fish according to claim 5, characterized in that, The transmission gear set includes two intermediate gears (608), which mesh with each other and are correspondingly meshed with the bottom gears (605) on the two side transmission components.

7. The amphibious biomimetic robotic fish according to claim 1, characterized in that, The pectoral fin portion (300) includes: The pectoral fin base plate (301) is located below the head (100) and is rotatable; The climbing claws are a number of each, all of which are set on the pectoral fin base plate (301) and arranged in a fan shape around the rotation center of the pectoral fin base plate (301), forming a climbing claw assembly that is symmetrically arranged on the pectoral fin base plate (301).

8. The amphibious biomimetic robotic fish according to claim 7, characterized in that, The crawler includes: The silicone pad is long and strip-shaped and fixed to the pectoral fin base plate (301); The inclined steel needle is fixed on the silicone pad and forms an acute angle with the surface of the pectoral fin substrate.

9. The amphibious biomimetic robotic fish according to claim 1, characterized in that, It also includes a pelvic fin (400) located below the abdomen (200) and capable of rotation.

10. The amphibious biomimetic robotic fish according to claim 1, characterized in that, The pelvic fin (400) and pectoral fin (300) have the same structure and can work together to enable the robotic fish to crawl.

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