A soft, biomimetic manta ray

Abstract

This invention provides a soft-bodied biomimetic manta ray. The manta ray body includes a soft outer shell, a floating trunk, a soft abdominal cover, and a floating tail component. The soft outer shell is cast from a soft material and consists of a soft torso and soft pectoral fins symmetrically distributed on both sides of the soft torso. The pectoral fins on both sides contain a first soft pectoral fin skeleton and a second soft pectoral fin skeleton. Both the first and second soft pectoral fin skeletons are equipped with several radiating fin nerve rays, each with at least one nerve node. The floating trunk is installed within an opening in the abdomen of the soft torso. The soft abdominal cover seals the opening and ensures the curved surface of the abdomen is intact and smooth. The undulating floating tail component is located at the tail end of the soft torso. This invention can simulate the nonlinear movement of the pectoral fins of a biological manta ray, causing the pectoral fins of the manta ray body to produce flexible wave-like deformation, making its underwater swimming posture more similar to that of a manta ray.

Description

Technical Field

[0001] This invention relates to underwater biomimetic robots, specifically to a soft-bodied biomimetic manta ray. Background Technology

[0002] Before the 1990s, inspired by marine organisms such as fish and cephalopods, scientists' research on underwater biomimetic robot structures mainly focused on theoretical research and model analysis. Initially, research on underwater biomimetic robots primarily focused on the design of tail fin propulsion modes, with tuna and dolphins being typical examples. With the development of research on biomimetic propulsion mechanisms, attention gradually shifted to the design of pectoral fin oscillation modes, with manta rays and bullnose ray being typical examples. These ray-like creatures rely on the oscillation of their large pectoral fins for agile navigating and snorkeling, while exhibiting greater stability than fish using tail fin propulsion. Furthermore, their flattened biological structure is more conducive to carrying payloads. Therefore, in recent years, more and more research institutions have invested in the design and fabrication of manta ray-shaped vehicles, injecting new materials and technologies into manta ray robot research. However, some shortcomings also exist.

[0003] Currently, some soft-touch biomimetic manta ray robotic fish have the following drawbacks:

[0004] (1) It is small in size and cannot mount functional sensors, so its applicability is low;

[0005] (2) The modular design is adopted, but there are gaps between the modules, which affects both the aesthetics and the propulsion effect of the pectoral fin flapping wings;

[0006] (3) Soft materials account for a small proportion and are only used in the pectoral fin part; the other structures are all rigid.

[0007] (4) The pectoral fin skeleton design is simple and does not easily reflect the pectoral fin structure of the biological manta ray;

[0008] (5) The soft material coverage of the outer surface is insufficient, and the rigid body is exposed too much. Summary of the Invention

[0009] This invention provides a soft biomimetic manta ray, which includes a soft shell cast from a soft material. The soft shell consists of a soft body and soft pectoral fins symmetrically distributed on both sides of the soft body. The soft pectoral fins on both sides are provided with a first soft pectoral fin skeleton and a second soft pectoral fin skeleton. Both the first and second soft pectoral fin skeletons are provided with a number of fin rays distributed in a divergent manner. The fin rays are located inside the soft pectoral fins and are fixedly connected to the soft pectoral fins. One end of the fin ray points to the soft body and the other end diverges towards the outer edge of the soft pectoral fin tip. Each fin ray has at least one nerve node.

[0010] The soft body has a main cavity with an opening on the abdomen. A floating main body is installed in the main cavity. The floating main body includes a floating chamber and a soft abdominal cover. The floating chamber and the soft body are fixedly connected. The floating chamber has a control chamber cavity. The control chamber cavity contains a core control board, a core structural component of the soft pectoral fin skeleton, and a third drive joint. The core structural component of the soft pectoral fin skeleton is used to drive the first and second soft pectoral fin skeletons on both sides to rotate so as to realize the biomimetic swing of the soft pectoral fins on both sides. The soft abdominal cover located at the opening on the abdomen of the soft body is sealed and fastened to the control chamber cavity. The lower surface of the soft abdominal cover is equipped with a height sensor connected to the core control board.

[0011] A floating tail component is fixedly installed inside the tail of the soft body. The floating tail component is connected to the third drive joint. The third drive joint is used to drive the floating tail component to rotate so as to realize the biomimetic swing of the tail of the soft body.

[0012] The soft body has a camera recess in the head, and a vision sensor (such as a binocular camera) connected to the core control board is installed in the camera recess.

[0013] Furthermore, the profile characteristics of the chordal cross-section of the soft pectoral fin conform to airfoil NACA0020, and the equation for airfoil NACA0020 is:

[0014] z up =0.4082x 0.5 -0.1260x -0.1860x 2 +0.0796x 3 -0.0150x 4

[0015] z down =-z up

[0016] Among them, z up The z-axis represents the upper contour feature value. down is the feature value of the lower contour in the z-axis direction, and x is the feature value in the x-axis direction.

[0017] Furthermore, a battery compartment is located near the head of the floating body, and batteries are installed in the battery compartment. The batteries include encapsulated lithium batteries and watertight connectors. A cable groove is provided between the battery compartment and the control cabin cavity for the watertight connectors to pass through. The encapsulated lithium batteries are connected to the core control board through the watertight connectors.

[0018] Furthermore, the core structural component of the soft pectoral fin skeleton includes a drive joint connector and a first drive joint and a second drive joint symmetrically installed on both sides of the drive joint connector. The first drive joint and the second drive joint pass through openings on both sides of the floatation chamber and are connected to the first soft pectoral fin skeleton and the second soft pectoral fin skeleton, respectively.

[0019] The first drive joint and the second drive joint are respectively provided with a first drive motor and a second drive motor for driving the first soft pectoral fin skeleton and the second soft pectoral fin skeleton.

[0020] Furthermore, both the first and second soft pectoral fin skeletons include pectoral fin supports, drive supports, and threaded fasteners;

[0021] The pectoral fin support is fixedly connected to the drive support via threaded fasteners. The drive support portion is exposed outside the main cavity and is connected to the output shafts on both sides of the core structural component of the soft pectoral fin skeleton using threaded fasteners.

[0022] The pectoral fin support consists of long, wing-shaped NACA0020 strips distributed along the head-to-tail direction. A row of fin nerve mounting holes is provided along the length of the pectoral fin support. One end of each fin nerve is fixedly connected to the fin nerve mounting hole, and the other end radiates toward the tip of the soft pectoral fin.

[0023] The fin nerves are taut, radiating, flexible nylon threads located within the soft pectoral fin. The central fin nerve is longer, while the fin nerves on the head and tail sides are shorter. The shape formed by the radiating fin nerves is similar to that of the soft pectoral fin. Each fin nerve has at least one plastic circular block arranged as a nerve node along its length direction, and the number of nerve nodes is proportional to the length of the fin nerve.

[0024] Furthermore, the tail section of the soft body is integrally molded with a flexible dorsal fin.

[0025] Furthermore, the soft body and the soft pectoral fins have a continuous posterior thin edge on the side near the tail. The maximum thickness of the posterior thin edge is 2-2.5 mm, and the maximum width is 20-20 mm. The outline features of the posterior thin edge are the same as those of the soft body shell, and a chamfer is provided at the connection between the posterior thin edge and the tip of the soft pectoral fin.

[0026] Furthermore, the third drive joint is equipped with a third drive motor.

[0027] The tail component of the float includes a tail buoyancy component and a third drive bracket. The tail buoyancy component is a flat wedge-shaped block with a groove on one side. The third drive bracket is fixedly installed in the groove and is connected to the output shaft of the third drive motor.

[0028] The advantages of this invention are:

[0029] (1) The soft shell is cast into one piece by soft material. The opening of the floating chamber is reserved in the belly of the soft shell and sealed with a soft belly cover. The soft shell and the soft belly cover fit tightly together, so that the curved surface of the back and belly of the manta ray is complete and smooth, and the inside of the manta ray is completely wrapped with soft material, that is, the surface is completely soft. The soft material has the characteristics of good flexibility and stretchability. The first soft pectoral fin skeleton and the second soft pectoral fin skeleton in the soft pectoral fins on both sides can simulate the nonlinear movement of the pectoral fins of the biological manta ray by relying on the characteristics of the soft material, so that the pectoral fins of the manta ray body produce flexible wave deformation.

[0030] (2) Diffuse fin nerves are provided in the soft pectoral fins on both sides, and the diverging direction is from the center line of the pectoral fin support to the outline of the front and rear edges of the manta ray body. The fin rays are made of flexible thread material, and 1 to 4 nerve nodes can be arranged on each fin ray. The nerve nodes are composed of hard and elastic material round blocks. The fin nerves can transmit the chord and spanwise waves of the soft pectoral fins, so that the pectoral fins on both sides of the manta ray body can produce smooth non-linear waves, and enhance the flexibility, so as to avoid the soft pectoral fins being too soft as a whole, which would cause the swimming posture to be unstable.

[0031] (3) Equipped with a visual sensor and an altitude sensor to acquire visual images, underwater height and other data. The manta ray body is equipped with a battery and a core control board. The battery can power the drive joints. The core control board is connected to the battery, visual sensor and altitude sensor through a watertight connector to communicate and process the data of each module in a timely manner, so that the manta ray body can perform underwater lighting, image acquisition and processing and altitude-fixed navigation.

[0032] (4) A flexible dorsal fin is integrally formed at the tail of the soft body, and a continuous trailing edge is provided on the side of the soft body and the soft pectoral fin near the tail. This plays a role in stabilizing the flow and guiding the tail flow during the propulsion of the manta ray, which can enhance environmental compatibility. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a front view schematic diagram of a soft biomimetic manta ray, as an embodiment of the present invention.

[0035] Figure 2 This is a side view of a soft biomimetic manta ray, as an embodiment of the present invention.

[0036] Figure 3This is a top view schematic diagram of a soft biomimetic manta ray, as an embodiment of the present invention.

[0037] Figure 4 This is a schematic diagram of the overall structure of a soft biomimetic manta ray, as an embodiment of the present invention.

[0038] Figure 5 This is a schematic diagram of the soft shell structure of a soft biomimetic manta ray, as an embodiment of the present invention.

[0039] Figure 6 This is a schematic diagram of the main floating structure of a soft biomimetic manta ray, as an embodiment of the present invention.

[0040] Figure 7 This is a schematic diagram of the soft abdominal flap structure of a soft biomimetic manta ray, as an embodiment of the present invention.

[0041] Figure 8 This is a schematic diagram of the floating tail component structure of a soft biomimetic manta ray, as an embodiment of the present invention.

[0042] Figure 9 This is a schematic diagram of the back structure of the soft shell of a soft biomimetic manta ray, as an embodiment of the present invention;

[0043] Figure 10 This is a schematic diagram of the nerve structure of the first fin of a soft biomimetic manta ray, as an embodiment of the present invention.

[0044] Figure 11 This is a schematic diagram comparing the structure of a soft biomimetic manta ray and a biological manta ray, representing an embodiment of the present invention.

[0045] Figure 12 This is a schematic diagram comparing the airfoil profile of a soft biomimetic manta ray and NACA0020, representing an embodiment of the present invention.

[0046] Figure 13 This is a schematic diagram of the first drive joint connection structure of a soft biomimetic manta ray according to an embodiment of the present invention;

[0047] Figure 14 This is a schematic diagram of a soft biomimetic manta ray height sensor structure, as an embodiment of the present invention.

[0048] Figure 15 This is a schematic diagram of the visual sensor structure of a soft biomimetic manta ray, which is an embodiment of the present invention.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-Soft outer shell; 101-Soft trunk; 1011-Piercing thin edge; 1012-Dorsal fin; 102-First soft pectoral fin skeleton; 1021-First fin ray nerve; 1022-First pectoral fin support; 1023-First drive support; 1024-First threaded fastener; 103-Second soft pectoral fin skeleton; 1031-Second fin ray nerve; 1032-Second pectoral fin support; 1033-Second drive support; 1034-Second threaded fastener; 104-Binocular camera;

[0051] 2-Main Float; 201-Float Cabin; 202-Battery; 2021-Lithium Battery Encapsulation Board; 2022-Watertight Connector Female Head; 203-Soft Pectoral Fin Core Structural Component; 2031-Drive Joint Connector; 2032-First Drive Joint; 2033-Second Drive Joint; 204-Core Control Board; 2041-Circuit Encapsulation Board; 2023-Watertight Connector Female Head;

[0052] 3-Soft hatch cover; 301-Soft hatch cover; 302-Hatch cover threaded fastener; 303-Altitude sensor;

[0053] 4-Stern component of the float; 401-Stern buoyancy component; 402-Third drive bracket; 403-Stern threaded fastener. Detailed Implementation

[0054] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0055] To fully understand this invention, detailed steps and structures will be presented in the following description to illustrate the technical solution of this invention. Preferred embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0056] This invention primarily addresses the structural design issues of biomimetic manta rays, optimizing problems such as soft material discontinuities at the drive joints, insufficient flexibility during pectoral fin actuation, low coverage of peripheral soft material, and inadequate sensor mounting. To address the insufficient flexibility during pectoral fin actuation, this invention designs pectoral fins cast from a soft material (existing technology, not detailed here) that possesses excellent elasticity and flexibility. Furthermore, the pectoral fins incorporate a neural network mimicking the fin rays of a manta ray, composed of fin rays and nerve nodes, enhancing flexibility. To further optimize the soft material discontinuities and low coverage at the drive joints, this invention designs a single, cast soft torso that integrates the pectoral fins, tail, and head, improving the coverage of peripheral soft material and preventing discontinuities at the drive joints. To address the practical mounting issue of sensors, this invention designs a floating main body with a visual sensor groove, which can accommodate cameras and LED lights of a certain size. This invention also designs a flexible underbody cover with a height sensor groove, which can accommodate altimeters of a certain size. The specific solutions are described below.

[0057] In an example of the present invention, such as Figures 1 to 4 As shown, it includes the manta ray body, which includes a soft outer shell 1, a floating main body 2, a soft underbelly 3, and a floating tail component 4.

[0058] The soft shell 1 consists of a soft torso 101 and soft pectoral fins symmetrically distributed on both sides of the soft torso 101. The soft torso 101 and the soft pectoral fins on both sides are cast into one piece using soft material through a mold of a certain shape, with the aim of obtaining a smooth and complete soft torso with curved surfaces. The soft torso 101 is provided with a camera recess, a main cavity, a thin trailing edge, and a dorsal fin. The soft pectoral fins on both sides are provided with a first soft pectoral fin skeleton 102 and a second soft pectoral fin skeleton 103 near the soft torso 101. The first soft pectoral fin skeleton 102 and the second soft pectoral fin skeleton 103 are symmetrical inside and are each provided with fin rays, pectoral fin supports, drive joint supports, and support threaded fasteners. The fin nerve consists of 12 flexible nylon threads, each thread can be arranged with 1 to 4 nerve nodes, used for the transmission of chordal and spanwise waves in the soft body, enabling the manta ray body to produce smooth nonlinear waves. The fin nerve has the same divergent characteristics as the fin nerve of biological manta rays, which is manifested as the root of the pectoral fin pointing to the tip.

[0059] The main body 2 of the floating body includes a floating body cabin 201, a battery 202, a soft pectoral fin skeleton core structural component 203, a core control board 204, and a third drive joint 205. The floating body cabin 201 is composed of floating body material with a pressure resistance depth of 300m or more. The profile characteristics of the maximum chordal cross section of the pectoral fin support conform to the airfoil NACA0020. The soft pectoral fin skeleton core structural component 203 includes a drive joint connector 2031, a first drive joint 2032, and a second drive joint 2033. The core control board 204 is connected to the battery 20, the first drive joint 2032, the second drive joint 2033, the third drive joint 205, the binocular camera 104, and the altitude sensor 303 through watertight connectors. The core control board 204 is made of epoxy resin material for potting and curing to ensure waterproof effect. The soft body cover 3 includes a soft body cover 301 and a height sensor 303. The soft body cover 301 fits tightly with the belly of the floating body 201 to ensure that the soft body shell 1 is fully covered by soft material from the back to the belly. The floating body tail component 4 includes a tail buoyancy component 401, a third drive bracket 402 and a third drive bracket threaded fastener 403. The floating body tail component 4 provides support for the tail of the soft body shell 1.

[0060] Soft shell 1 such as Figure 5 As shown, the system includes a soft torso 101, a second soft pectoral fin skeleton 102, a second soft pectoral fin skeleton 103, and a binocular camera 104. The head of the soft torso 101 has a camera groove, the internal shape of which is the same as the bottom shape of the binocular camera 104. It has a certain depth but does not completely nest the binocular camera 104. A certain amount of glue is applied to the inner wall of the camera groove to fix the binocular camera 104. The abdomen of the soft torso 101 has a main cavity, which is semi-closed with the opening facing downwards. The main cavity has a certain space, and its shape is basically the same as the assembly of the main floating body 2 and the tail floating body 3, thus achieving a tightly wrapped installation effect. The tail of the soft torso 101 has a thin trailing edge and a dorsal fin. The left and right parts of the soft torso 101 are soft pectoral fins, which are key structures for transmitting flexible waves.

[0061] In this embodiment of the invention, the first soft pectoral fin skeleton 102 and the second soft pectoral fin skeleton 103 are symmetrical about the cross-section of the soft outer shell 101 at the point of maximum thickness (i.e., Figure 3The thickness is along the z-axis. The first soft pectoral fin skeleton 102 is provided with a first pectoral fin support 1022, a first drive support 1023, and a first threaded fastener 1024. The contour features of the maximum cross-section of the first pectoral fin support 1022 satisfy NACA0020. The through hole at the head of the first pectoral fin support 1022 is connected to the first drive support 1023 through the first threaded fastener 1024. The through hole on the first pectoral fin support 1022 can be passed through by an M3 screw. The first drive support 1023 is partially exposed inside the main cavity for connection with the drive joint connector 2031, i.e., connected using the first threaded fastener 1024. Figure 10 The first pectoral fin support 1022 has a row of 12 fin nerve mounting holes along its central axis. One end of each first fin nerve 1021 is fixedly connected to a mounting hole, and each first fin nerve 1021 is in a taut state. The first fin nerve 1021 is made of flexible nylon wire, and each wire can be arranged with 1 to 4 plastic round blocks as nerve nodes. The arrangement is shown in the diagram of the manta ray structure. Figure 11 The first fin nerve 1021 is used to transmit chordal and spanwise waves in the first soft pectoral fin on the left side of the soft body 101, enabling smooth nonlinear waves to occur on the left side of the manta ray body.

[0062] The second soft pectoral fin skeleton 103 includes a second fin nerve 1031, a second pectoral fin support 1032, a second drive support 1033, and a second threaded fastener 1034. The maximum cross-sectional profile of the second pectoral fin support 1032 satisfies NACA0020. A through-hole at the head of the second pectoral fin support 1032 connects to the second drive support 1033 via the second threaded fastener 1034. An M3 screw can pass through the through-hole on the second pectoral fin support 1032. The second drive support 1033 is partially exposed outside the main cavity for connection to the drive joint connector 2031, i.e., via the second threaded fastener 1034. Figure 10 The second pectoral fin support 1032 has a row of 12 fin nerve mounting holes along its central line along its length. One end of each second fin nerve 1031 is fixedly connected to the mounting hole, and each second fin nerve 1031 is in a taut state. Each second fin nerve 1031 is a flexible nylon wire, and each wire can be arranged with 1 to 4 plastic round blocks as nerve nodes. The arrangement is based on the structure diagram of a manta ray. The second fin nerve 1031 is used for the chordal and spanwise wave transmission of the second soft pectoral fin on the right side of the soft body 101, enabling smooth nonlinear waves to occur on the right side of the manta ray body.

[0063] The number of nerve nodes is directly proportional to the length of the fin rays; that is, the longer the fin ray nerve, the more nerve nodes it contains. The fin ray nerves exhibit the same divergent pattern as those in manta rays, with the divergence pattern showing the nerves pointing from the base of the pectoral fin to the tip.

[0064] In this example, the profile characteristics of the chordal cross-section of the manta ray's soft shell conform to airfoil NACA0020, as shown below. Figure 12 As shown, the profile characteristics of the chordal cross-section of the pectoral fin support conform to airfoil NACA0020, and the equation of airfoil NACA0020 is:

[0065] z up =0.4082x 0.5 -0.1260x -0.1860x 2 +0.0796x 3 -0.0150x 4

[0066] z down =-z up

[0067] Where z up The z-axis represents the upper contour feature value. down is the feature value of the lower contour in the z-axis direction, and x is the feature value in the x-axis direction.

[0068] In an example of the present invention, such as Figure 6 As shown, the main body 2 of the floating body includes a floating body compartment 201, a battery 202, a soft pectoral fin skeleton core structure component 203, a core control plate 204, and a third drive joint 205. The floating body compartment 201 is composed of a floating body material, which is rigid and can both install internal parts and provide greater buoyancy for the manta ray body. The floating body material is required to withstand a pressure depth of 300m or more. The head of the floating body compartment 201 has a battery recess with a certain depth to fully accommodate the battery. Because the battery 202 is small, no other fixing method is needed. The soft body 101 will prevent the battery 202 from falling off. The battery recess has a square groove on the inner wall of the control compartment for watertight connectors to pass through. The belly of the floating body compartment 201 has an open control compartment cavity for accommodating the core control plate 204 and the soft pectoral fin skeleton core structure component 203. The tail of the floating body compartment 201 has a tail threaded hole, which is connected to the tail of the floating body 3 by threaded fasteners. Battery 202 includes a potted lithium battery 2021 and a watertight female connector 2022. A watertight female connector 2022 is connected to the core control board via a watertight connector. Both ends of the watertight connector used for connection are male. The watertight connector has good waterproof performance.

[0069] The core structural component 203 of the soft pectoral fin skeleton includes a drive joint connector 2031, a first drive joint 2032, and a second drive joint 2033. The drive joint connector 2031 has threaded holes symmetrically arranged on both sides. The first drive joint 2032 is connected to the drive joint 2032 by threaded fasteners, and the second drive joint 2033 is connected to the drive joint 2033 by threaded fasteners. The core control board 204 includes a potted circuit board 2041 and a watertight connector female head 2042. The potted circuit board 2041 is made by pouring epoxy resin material, which has good waterproof properties. It can minimize the size of the control system and has a regular shape, which is easy to install. It is connected to the battery 202, the core structural component 203 of the soft pectoral fin skeleton, the binocular camera 104, and the altitude sensor 303 through the watertight connector. It is the key to the manta ray's body performing actions, obtaining underwater images, and navigating according to its height above the seabed.

[0070] like Figure 7 As shown, the soft hull cover includes a soft hull cover, a height sensor, and threaded fasteners for the hull cover. The soft hull cover has a height sensor groove and a hull cover through hole. The height sensor groove is open on both sides for nesting the height sensor, which is then fixed with glue. The height sensor groove contains a cable channel for the height sensor cable to pass through. According to the height sensor's usage method, the installation direction is with the back facing the abdomen, and the height sensor part is exposed on the outside of the manta ray's body, which is conducive to more accurate acquisition of the height above the bottom. The hull cover through hole has 8 M3 through holes for connecting the soft hull cover and the floating body, which ensures a tight connection and prevents it from falling off.

[0071] like Figure 8 As shown, the tail component 4 of the float includes a tail buoyancy component 401, a third drive bracket 402, and a tail threaded fastener 403. The tail buoyancy component 401 is provided with a bracket groove with the opening facing upward. Eight threaded through holes are provided at the bottom for the placement and fixation of the third drive bracket 402. The third drive bracket 402 is partially exposed outside the tail buoyancy component 401. The third drive bracket is connected to the tail buoyancy component through the tail threaded fastener 403.

[0072] In this example, as Figure 4The diagram illustrates the connection between the soft outer shell 1, the main float 2, the soft belly cover 3, and the tail float 4. The main float 2 is tightly encased in the soft outer shell and provides primary support for the soft outer shell 1. This design facilitates the disassembly and installation of the main float 2, while also ensuring that the manta ray's fluid shape resembles that of a biological manta ray in both static and dynamic states. Furthermore, the first soft pectoral fin skeleton 102 is connected to the main float 2 via threaded fasteners connecting the first drive bracket 1023 and the drive joint connector 2031. The second soft pectoral fin skeleton 103 is connected to the main float 2 via threaded fasteners connecting the second drive bracket 1033 and the second drive joint 2033. The main body 2 is connected to the soft body cover 3, which is connected to the float chamber 201 through the cover threaded fastener 302 to achieve the connection with the float body main body 2. At the same time, the soft body cover 3 supports and protects the core electronic control board 204 built into the float chamber in the float body main body 2, and can achieve the effect of tight fit with the soft body shell 1, so that the abdominal curved surface of the manta ray body is complete and smooth. The size of the soft body cover 301 should not be too large, otherwise the phenomenon of soft body transition discontinuity may occur. The float body tail component 4 is located at the tail of the main body cavity and is connected to the float body main body 2 through threaded fasteners. Together with the float body main body 2, it supports the soft body shell 1, but the float body tail component 4 mainly supports the tail of the soft body shell 1.

[0073] In this example, the manta ray body includes a first drive joint 2032, a second drive joint 2033, and a third drive joint 205. The three drive joints have the same structure. Taking the first drive joint 2032 as an example, the structural diagram is as follows. Figure 13As shown, the system includes a motor, drive bracket, short drive bracket, toothed rudder, and toothless rudder, all connected by threaded fasteners. The soft body can be longitudinally divided into two parts: a first pectoral fin and a second pectoral fin. The first drive joint 2032 is the power source for the spanwise and chordwise undulations of the first soft pectoral fin, the second drive joint 2033 is the power source for the spanwise and chordwise undulations of the second soft pectoral fin, and the third drive joint 205 is the power source for the tail undulations of the manta ray. When the first drive joint 2032 and the second drive joint 2033 oscillate synchronously with a certain amplitude, and the third drive joint 2034 is at zero position, the manta ray gains forward thrust and performs a forward movement. When the first drive joint 2032 oscillates synchronously with a certain amplitude, and the second drive joint 2033 and the third drive joint 205 are at zero position, the manta ray performs a left turn. When the second drive joint 2033 oscillates with a certain amplitude, and the first drive joint 2031 and the third drive joint 2033 are at zero position... When the manta ray body performs a left turn, and the first drive joint 2031 and the second drive joint 2033 swing synchronously with a certain amplitude, while the third drive joint 2033 is fixed in the upward swing position, the manta ray body obtains upward lift and performs an upward movement. When the first drive joint 2032 and the second drive joint 2033 swing synchronously with a certain amplitude, while the third drive joint 205 is fixed in the downward swing position, the manta ray body obtains downward lift and performs a diving movement. The soft-bodied biomimetic manta ray of the present invention has high biomimetic motion and efficient propulsion performance.

[0074] The curved surfaces of the manta ray's back and abdomen are complete, smooth, and without any breaks. The soft body surface area accounts for nearly 100%. The first soft pectoral fin skeleton 102 and the second soft pectoral fin skeleton 103 are driven by the first drive joint 2032 and the second drive joint 2033. Relying on the flexibility of the soft material, the nonlinear movement of the manta ray's pectoral fin can be simulated. Compared with traditional propeller propulsion, it causes less disturbance to the water flow and has stronger environmental compatibility.

[0075] The first fin nerve 1021 and the second fin nerve 1031 are symmetrically arranged inside the soft body trunk. Taking the first fin nerve 1021 in the right soft pectoral fin as an example, the following explanation is provided: Figure 10 As shown, the right soft pectoral fin contains 12 fin rays 1021-1 of varying lengths, serving as the first fin ray nerve 1021. Fin rays 1021-1 are made of flexible nylon thread and can be fitted with 1 to 4 plastic circular blocks as nerve nodes 1021-2, simulating the radius structure at the intersection of the fin rays. The first fin ray nerve 1021 within the right soft pectoral fin is asymmetrical vertically; in the head-to-tail direction, the middle fin ray 1021-1 is longer, while the upper and lower flanks are shorter, radiating outwards from the center line of the pectoral fin support towards the anterior and posterior contours of the manta ray's body.

[0076] A comparison of the main structure of a manta ray's body with that of a biological manta ray reveals that the manta ray's body simplifies the tail section of the biological manta ray, such as... Figure 11 The image shown is a comparison between the biological manta ray and the manta ray body of this application. The tail of the soft shell 1 is provided with a trailing thin edge 1011 and a dorsal fin 1012, which can straighten the tail water flow. The maximum thickness of the trailing thin edge is 2.37 mm and the maximum width W is 16 mm. The outline features of the trailing thin edge are the same as the outline features of the soft shell. A chamfer is provided at the connection between the trailing thin edge and the tip of the soft pectoral fin skeleton. The chamfer is easy to implement in the process. The trailing thin edge 1011 and the dorsal fin 1012 play a role in stabilizing the flow and guiding the tail flow during the propulsion of the manta ray body, which can enhance environmental compatibility.

[0077] Depend on Figure 4 As can be seen, the head of the soft casing 2 has a camera recess, which is fixed with glue. Figure 15 The visual sensor shown enables the manta ray to obtain forward-looking underwater images and provide forward-looking underwater illumination. A height sensor slot is located on the soft underside of the body and is fixed with glue. Figure 15 The height sensor shown enables the manta ray to obtain data on its height above the water surface, allowing it to perform altitude-hold navigation based on the height data. The manta ray's body is equipped with a battery 202, which powers electronic components such as the binocular camera 104, the first drive joint 2032, the second drive joint 2033, the core control board 204, and the height sensor 303. The core control board 204 is connected to the binocular camera 104 and the height sensor 303 through a watertight connector, and processes the signals and data of each functional module.

[0078] In summary, the soft biomimetic manta ray provided by this invention has a near 100% soft body coverage and pectoral fins that can produce good flexible undulations, making the biomimetic manta ray highly compatible with the underwater environment and with a higher degree of overall static biomimicry. It can mimic the left and right turns, surfacing and diving of biological manta rays, and has the advantage of high maneuverability. In addition, it is equipped with a visual sensor and an altitude sensor, which can realize underwater lighting, underwater image acquisition and transmission, and altitude-holding navigation functions.

[0079] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A soft, biomimetic manta ray, characterized in that, The soft biomimetic manta ray includes a soft shell (1) cast from soft material. The soft shell (1) consists of a soft body (101) and soft pectoral fins symmetrically distributed on both sides of the soft body (101). The soft pectoral fins on both sides are provided with a first soft pectoral fin skeleton (102) and a second soft pectoral fin skeleton (103). The first soft pectoral fin skeleton (102) and the second soft pectoral fin skeleton (103) are provided with a number of fin nerves distributed in a divergent manner. The fin nerves are located inside the soft pectoral fins and are fixedly connected to the soft pectoral fins. One end of the fin nerve points to the soft body (101), and the other end diverges towards the outer edge of the soft pectoral fin tip. Each fin nerve is provided with at least one nerve node. A main cavity is provided within the soft body trunk (101), and a floating main body (2) is installed within the main cavity. The floating main body (2) includes a floating body compartment (201) and a soft body cover (3). The floating body compartment (201) and the soft body trunk (101) are fixedly connected. The floating body compartment (201) has a control compartment cavity, within which a core control board (204), a core structural component of the soft pectoral fin skeleton (203), and a third drive joint (205) are installed. The core structural component (203) of the pectoral fin skeleton is used to drive the first soft pectoral fin skeleton (102) and the second soft pectoral fin skeleton (103) on both sides to rotate so as to realize the bionic swing of the soft pectoral fins on both sides. The soft abdominal cover (3) is sealed and fastened to the cavity of the control cabin, and the soft abdominal cover (3) is sealed and fitted to the abdominal opening of the soft body (101). The lower surface of the soft abdominal cover (3) is provided with a height sensor (303) connected to the core control plate (204). A floating tail component (4) is fixedly provided inside the tail of the soft body (101). The floating tail component (4) is connected to the third drive joint (205). The third drive joint (205) is used to drive the floating tail component (4) to rotate so as to realize the bionic swing of the tail of the soft body (101). The soft body (101) has a camera recess in its head, and a vision sensor connected to the core control board (204) is installed in the camera recess.

2. The soft-bodied biomimetic manta ray as described in claim 1, characterized in that, The profile characteristics of the soft pectoral fin's chordal cross-section conform to airfoil NACA0020, and the equation for airfoil NACA0020 is: z up =0.4082x 0.5 -0.1260x-0.1860x 2 +0.0796x 3 -0.0150x 4 With down =-z up Among them, z up The z-axis represents the upper contour feature value. down is the feature value of the lower contour in the z-axis direction, and x is the feature value in the x-axis direction.

3. The soft-bodied biomimetic manta ray as described in claim 1, characterized in that, The floating body (201) has a battery compartment near the head, and a battery (202) is installed in the battery compartment. The battery (202) includes a potted lithium battery (2021) and a watertight connector (2022). A cable groove is provided between the battery compartment and the control compartment cavity for the watertight connector (2022) to pass through. The potted lithium battery (2021) is connected to the core control board (204) through the watertight connector (2022).

4. A soft-bodied biomimetic manta ray as described in claim 1, characterized in that, The core structural component (203) of the soft pectoral fin skeleton includes a drive joint connector (2031) and a first drive joint (2032) and a second drive joint (2033) symmetrically installed on both sides of the drive joint connector (2031). The first drive joint (2032) and the second drive joint (2033) pass through the openings on both sides of the floating body (201) and are connected to the first soft pectoral fin skeleton (102) and the second soft pectoral fin skeleton (103), respectively. The first drive joint (2032) and the second drive joint (2033) are respectively provided with a first drive motor and a second drive motor for driving the first soft pectoral fin skeleton (102) and the second soft pectoral fin skeleton (103).

5. A soft-bodied biomimetic manta ray as described in claim 1 or 4, characterized in that, Both the first soft pectoral fin skeleton (102) and the second soft pectoral fin skeleton (103) include a pectoral fin support, a drive support, and threaded fasteners; The pectoral fin support is fixedly connected to the drive support by threaded fasteners. The drive support is partially exposed outside the main cavity and is connected to the output shafts on both sides of the core structural component (203) of the soft pectoral fin skeleton using threaded fasteners. The pectoral fin support consists of long, wing-shaped NACA0020 strips distributed along the head-to-tail direction. A row of fin nerve mounting holes is provided along the length of the pectoral fin support. One end of each fin nerve is fixedly connected to the fin nerve mounting hole, and the other end radiates toward the tip of the soft pectoral fin. The fin nerves are taut, radiating, flexible nylon threads located within the soft pectoral fin. The central fin nerve is longer, while the fin nerves on the head and tail sides are shorter. The shape formed by the radiating fin nerves is similar to that of the soft pectoral fin. Each fin nerve has at least one plastic circular block arranged as a nerve node along its length direction, and the number of nerve nodes is proportional to the length of the fin nerve.

6. A soft, biomimetic manta ray as described in claim 1, characterized in that, The soft body (101) has a flexible dorsal fin (1012) integrally formed at the tail. Furthermore, the soft body (101) and the soft pectoral fin have a continuous posterior thin edge (1011) on the side near the tail. The maximum thickness of the posterior thin edge (1011) is 2-2.5 mm, and the maximum width is 20-20 mm. A chamfer is provided at the connection between the posterior thin edge (1011) and the soft pectoral fin.

7. A soft-bodied biomimetic manta ray as described in claim 1, characterized in that, The third drive joint (205) is equipped with a third drive motor. The tail component (4) of the float includes a tail buoyancy component (401) and a third drive bracket (402). The tail buoyancy component (401) is a flat wedge-shaped block with a groove on one side. The third drive bracket (402) is fixedly installed in the groove and is connected to the output shaft of the third drive motor.

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