Active bending flexible pectoral fin structure for cow-nosed ray imitated underwater robot

Abstract

The utility model provides an active bending flexible pectoral fin structure for a cow-nosed ray imitating underwater robot. The active bending flexible pectoral fin structure comprises a supporting seat, a plurality of vertical plates, a first flexible connecting plate, a second flexible connecting plate and a driving assembly, all the vertical plates are arranged on one side of the supporting seat at intervals in the left-right direction, the first flexible connecting plate is movably connected with the upper portion of each vertical plate, and one end of the first flexible connecting plate is fixedly connected with the supporting seat. The second flexible connecting plate is movably connected with the lower portion of each vertical plate, one end of the second flexible connecting plate is fixedly connected with the supporting seat, the driving assembly is arranged on the supporting seat, the vertical plate closest to the supporting seat is in transmission connection with the driving assembly, and all the vertical plates swing in the unfolding direction of the pectoral fin in a wave mode under the action of the driving assembly. According to the structure, through cooperation of the vertical plate and the flexible connecting plate, active wave-shaped bending of the pectoral fins is achieved, movement continuity is ensured, water flow turbulence is avoided, and water resistance is reduced; the structure is simple, swimming postures are convenient to control, and propelling efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of underwater biomimetic robot technology, specifically to an active bending flexible pectoral fin structure for a cow-nose ray-inspired underwater robot. Background Technology

[0002] With increasing emphasis on marine environmental protection and marine resource development, a variety of marine monitoring technologies and equipment have emerged. Among them, biomimetic underwater robots have become a popular technology in recent years. The cownose ray-inspired underwater robot, with its advantages of high biomimicry, low noise, and animal-friendly characteristics, has pointed out a new direction for the development of marine environmental protection and monitoring technologies.

[0003] The bullnose ray-inspired underwater robot uses its pectoral fins to flap, creating a wave-like motion that generates forward thrust in the water. Therefore, the flexible deformation of the pectoral fins is crucial for improving swimming efficiency and controlling posture. Currently, the mainstream structures of existing bullnose ray-inspired robots, both domestically and internationally, are either cable-driven or joint-driven with multiple rotary actuators.

[0004] The pull-line drive method uses guide wheels to transmit tension and deform the pectoral fins. However, the large number of guide wheels makes adjusting the line tension extremely difficult. On the one hand, the line is prone to creep under long-term stress, and the difference in friction coefficients between different guide wheels exacerbates the tension imbalance, causing asymmetrical deformation of the pectoral fins and directly affecting propulsion efficiency. On the other hand, the mechanical wear between the guide wheels and the line is severe. Under an average of 8 hours of continuous operation per day, the line's service life is less than 20 days, resulting in high maintenance costs.

[0005] The multi-rotary-drive joint actuation method divides the pectoral fin plate into multiple joint segments, each controlled by an independent rotary drive. While this achieves segmented motion, it suffers from a significant "rigid connection" problem. During movement, abrupt changes in the rotation angle of adjacent joint segments can disrupt the continuity of pectoral fin undulations, causing turbulence on the fin surface and increasing water resistance. Furthermore, the complex collaborative control algorithm for multiple rotary drives means that differences in the power output of each drive can further amplify motion incoordination, reducing swimming efficiency and potentially causing robot posture oscillations.

[0006] The two methods mentioned above are both difficult to accurately simulate the natural flexible wave characteristics of the bullnose ray's pectoral fin. Therefore, this invention proposes a pectoral fin structure that can achieve active bending and flexible deformation, as well as a bullnose ray-inspired underwater robot that is beneficial for marine environmental protection and monitoring applications. Utility Model Content

[0007] The present invention addresses the technical problems of poor control over the swimming posture, poor continuity of movement, and low swimming efficiency of existing pectoral fin structures. To overcome the shortcomings of the prior art, the present invention provides a method that uses a combination of several upright plates and two flexible connecting plates to achieve the active wavy bending of the pectoral fin, which facilitates the control of the swimming posture, ensures the continuity of the pectoral fin movement, and improves the overall swimming efficiency.

[0008] To achieve the purpose of this utility model, the following technical solution is adopted:

[0009] An active bending flexible pectoral fin structure for an underwater robot inspired by a bullnose ray includes a support base, several upright plates, a first flexible connecting plate, a second flexible connecting plate, and a drive assembly. All upright plates are arranged at intervals along one side of the support base in a left-right direction. The first flexible connecting plate is movably connected to the upper part of each upright plate, and one end of the first flexible connecting plate is fixedly connected to the support base. The second flexible connecting plate is movably connected to the lower part of each upright plate, and one end of the second flexible connecting plate is fixedly connected to the support base. The drive assembly is mounted on the support base, and the upright plate closest to the support base is drive-connected to the drive assembly. Under the action of the drive assembly, all upright plates oscillate in a wave-like manner along the pectoral fin's unfolding direction. This structure, through the cooperation of the upright plates and flexible connecting plates, overcomes the problems of uneven tension and severe wear in wire-driven systems, as well as the "rigid connection" and discontinuous motion problems of multiple rotating drive components. It achieves active wave-like bending of the pectoral fin, ensuring continuous motion, avoiding water turbulence, and reducing water resistance. The structure is simple, requiring no complex wires or multiple drive components, facilitating control of swimming posture and improving propulsion efficiency.

[0010] Preferably, the drive assembly includes a rotary drive component, a swing arm, and a swing arm rotating component. The rotary drive component is mounted on a support base, and its drive shaft is oriented in a front-to-back direction. One end of the swing arm is fixedly connected to the drive shaft of the rotary drive component, and the other end is fixedly connected to the swing arm rotating component. The swing arm rotating component is rotatably connected to a vertical plate closest to the support base, and its rotation direction is the same as that of the drive shaft. Driven by the drive shaft, the connection end between the swing arm and the swing arm rotating component swings back and forth around the drive shaft as the rotation center. This drive assembly replaces the complex structure of multiple rotary drive components, avoiding the difficulties in coordinated control of multiple drive components and the motion incoordination caused by differences in power output. It uses a single rotary drive component, simplifying the structure and reducing costs. Through the transmission between the swing arm and the swing arm rotating component, stable swinging of the vertical plate is achieved, reducing control complexity, improving motion coordination, and indirectly improving swimming efficiency.

[0011] Preferably, a through hole is provided in the left-right direction on the upright plate near the support base; a swing arm support block is provided on the upright plate at the through hole; the swing arm support block is provided with shaft holes distributed in the front-back direction; the swing arm rotating component is provided with a rotating shaft distributed in the front-back direction, and the rotating shaft is rotatably connected in the shaft holes, realizing the left-right rotation of the swing arm rotating component in the through hole. The rigid cooperation of the swing arm support block and the rotating shaft enhances the stability of the driving force transmission, reduces mechanical wear, ensures that the power of the driving component is efficiently transmitted to the upright plate, avoids energy loss, and extends the service life of the equipment.

[0012] Preferably, the swing arm support blocks are symmetrically arranged on both sides of the through hole on the upright plate, and the shaft holes on the two swing arm support blocks are coaxially arranged; the rotating shafts are provided on both sides of the swing arm rotating component, and the rotating shafts on the front and rear sides are coaxially arranged; the rotating shafts on the front and rear sides respectively rotate and engage with the shaft holes on the front and rear swing arm support blocks. This structure avoids the problem of asymmetrical deformation of the pectoral fins caused by unilateral force in cable-driven propulsion, and the bidirectional symmetrical support ensures balanced force on the upright plate, preventing tilting during movement, ensuring symmetrical deformation of the pectoral fins, reducing water resistance interference, and improving propulsion efficiency and attitude stability.

[0013] Preferably, each upright plate has connecting shafts distributed in a front-to-back direction at its upper and lower parts; the first flexible connecting plate is rotatably connected to the upper connecting shaft of each upright plate; the second flexible connecting plate is rotatably connected to the lower connecting shaft of each upright plate. The connection via the connecting shafts allows for more flexible relative movement between the flexible connecting plates and the upright plates, ensuring a smooth transition during oscillation through the traction of the flexible connecting plates, without abrupt changes in angle, thus guaranteeing the continuity of the pectoral fin's undulations and reducing turbulence.

[0014] Preferably, each upright plate has mounting grooves at its upper and lower parts; the connecting shafts on the upper and lower sides are respectively installed in the mounting grooves on the upper and lower sides. The mounting grooves further save installation space.

[0015] Preferably, the outer end of the first flexible connecting plate is rotatably connected to a connecting shaft on the upper side of the outermost upright plate; the outer end of the second flexible connecting plate is rotatably connected to a connecting shaft on the lower side of the outermost upright plate. This avoids the problem of uncontrolled movement at the end of the pectoral fin or disconnection from the overall wave motion, achieving full-range coordinated movement from the support base to the outermost upright plate, ensuring that the wave-like oscillation covers the entire pectoral fin without any dead angles, further enhancing the continuity and integrity of the wave motion, and improving propulsion efficiency.

[0016] Preferably, the length of all uprights gradually decreases from the direction closest to the support base to the direction furthest from the support base. This gradual length design conforms to the natural shape of the bullnose ray's pectoral fin, which is "thicker near the body and thinner towards the distance," enhancing the biomimetic effect and reducing interference with aquatic organisms.

[0017] Preferably, the outer side of the outermost vertical plate is provided with fin tips distributed in a left-right direction. The fin tips enhance end-flow control, reduce water resistance, and improve the guidance of the wave, making the propulsion more efficient.

[0018] Preferably, both the first and second flexible connecting plates are thin plates made of nylon material. Nylon material combines flexibility, strength, and corrosion resistance, making it suitable for underwater environments; its flexibility can meet the requirements of wave-shaped bending, and its wear resistance reduces mechanical wear, lowers maintenance costs, and extends service life.

[0019] In summary, the advantages of this utility model include the following five points:

[0020] 1. Improved motion continuity and swimming efficiency: Through the combination structure of "several upright plates + two flexible connecting plates", the upright plates can form a wave-shaped active bending under the action of the drive components, avoiding the asymmetrical deformation problem of the pectoral fins in the existing pull-wire drive, as well as the problems of sudden angle changes and water flow turbulence caused by the "rigid connection" of multiple rotating drive components, ensuring continuous and smooth pectoral fin undulation, effectively reducing water resistance and significantly improving swimming efficiency.

[0021] 2. Simplified structure and control, reduced cost: The pectoral fin movement is driven by a single rotary drive component through components such as the swing arm and the swing arm rotating component, which replaces the complex guide wheel system or multiple rotary drive components in the existing technology. This reduces the number of parts and mechanical wear (such as wear between the line and the guide wheel), and lowers maintenance costs. At the same time, it avoids the algorithmic complexity of multi-drive component collaborative control, which facilitates precise control of swimming attitude and reduces the risk of attitude oscillation.

[0022] 3. Enhanced power transmission stability and equipment lifespan: The drive assembly achieves rigid fit through structures such as flanges, swing arm support blocks, and rotating shafts. Support and rotating components are symmetrically arranged on the front and rear sides of the upright plate to ensure balanced and stable transmission of driving force and reduce energy loss. The flexible connecting plate is made of wear-resistant and corrosion-resistant nylon material, which can significantly extend the service life compared with the existing wire-driven line.

[0023] 4. Optimize biomimetic performance and reduce environmental interference: The upright plate adopts a length gradient design, arc end face and sharp corner structure, combined with a flexible connecting plate with full-range coordinated movement, to accurately simulate the natural shape and wave characteristics of the bullnose ray's pectoral fin; the overall structure operates in a biomimetic manner, which greatly reduces interference with the underwater environment and aquatic organisms, making it more suitable for marine environmental protection and monitoring scenarios.

[0024] 5. Achieve flexible motion control: By placing this structure on both sides of the bullnose ray-inspired underwater robot, the navigation direction can be controlled by the difference in the flapping frequency of the pectoral fins on both sides, giving the robot flexible attitude control capabilities to meet the diverse needs of underwater operations. Attached Figure Description

[0025] Figure 1 is a structural schematic diagram of the actively bending flexible pectoral fin structure used in the bullnose ray-inspired underwater robot of this utility model. Figure 2 is a structural schematic diagram of the actively bending flexible pectoral fin structure of this utility model from a first-view perspective. Figure 3 is a structural schematic diagram of the actively bending flexible pectoral fin structure of this utility model from a second-view perspective. Figure 4 is an exploded view of the actively bending flexible pectoral fin structure of this utility model. Figure 5 is a structural schematic diagram of the upright plate of this utility model. Explanation of reference numerals:

[0026] 1. Support base; 2. Vertical plate; 201. Primary vertical plate; 202. Secondary vertical plate; 203. Tertiary vertical plate; 204. Quaternary vertical plate; 205. Fifth vertical plate; 21. Through hole; 22. Swing arm support block; 221. Shaft hole; 23. Mounting groove; 24. Connecting shaft; 25. First arc; 26. Second arc; 27. First sharp corner; 28. Second sharp corner; 3. First flexible connecting plate; 4. Second flexible connecting plate; 5. Rotary drive component; 51. Drive shaft; 52. Flange; 6. Swing arm; 7. Swing arm rotating component; 71. Rotating shaft; 8. Fin tip plate. Detailed Implementation

[0027] First, those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the embodiments of this application and are not intended to limit the scope of protection of the embodiments of this application. Those skilled in the art can make adjustments as needed to adapt to specific application scenarios.

[0028] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0029] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0030] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0031] The pectoral fins on both sides of the bullnose ray-inspired underwater robot represent the left and right sides of this embodiment, while the head and tail represent the front and back directions. The upper and lower parts of the bullnose ray-inspired underwater robot represent the up and down directions.

[0032] like Figures 1 to 5 As shown, an active bending flexible pectoral fin structure for a bullnose ray-inspired underwater robot includes a support base 1, several upright plates 2, a first flexible connecting plate 3, a second flexible connecting plate 4, and a drive assembly. The support base 1 is fixedly mounted on one side of the bullnose ray-inspired underwater robot in the left-right direction by screws. All the upright plates 2 are arranged at intervals in the left-right direction on the left or right side of the support base 1. The first flexible connecting plate 3 is movably connected to the upper part of each upright plate 2, and one end of the first flexible connecting plate 3 is fixedly connected to the upper part of the support base 1 by screws. The second flexible connecting plate 4 is connected to each upright plate 2 in the left-right direction. The lower part of the upright plate 2 is movably connected, and one end of the second flexible connecting plate 4 is fixedly connected to the lower part of the support base 1 by screws. The drive component is set on the support base 1, and the upright plate 2 closest to the support base 1 is connected to the drive component. Under the action of the drive component, all the upright plates 2 swing in a wave-like (up and down) manner along the pectoral fin deployment direction (left and right direction). In addition, a silicone pectoral fin sleeve imitating a bullnose ray is also covered outside the active bending flexible pectoral fin structure, and the opening of the silicone pectoral fin sleeve is fixedly connected to the main cabin of the bullnose ray-imitating underwater robot. This structure, through the cooperation of the upright plate 2 and the flexible connecting plate, overcomes the problems of uneven tension and severe wear of the cable drive, as well as the "rigid connection" and discontinuous motion problems of multiple rotating drive components. It realizes the active wave-like bending of the pectoral fin, ensures the continuity of motion, avoids water turbulence, and reduces water resistance. The structure is simple, without the need for complex cables or multiple drive components, which facilitates the control of swimming posture and improves propulsion efficiency.

[0033] like Figures 2 to 5As shown, in this embodiment, there are five upright plates 2, arranged sequentially from closest to the support base 1 to furthest away from it: primary upright plate 201, secondary upright plate 202, tertiary upright plate 203, quaternary upright plate 204, and quinary upright plate 205. These five upright plates 2 are arranged at equal intervals. This equidistant design of the five upright plates 2 is a biomimetic optimization of the natural morphology of the bullnose ray's pectoral fin, accurately simulating the undulating rhythm of the fin, making the water flow more in line with natural laws, and improving swimming efficiency and biomimetic effect. Furthermore, the length of the five upright plates 2 gradually decreases from near the support base 1 to far away from the support base 1. The five upright plates 2 also have similar structures: the upper surface of each upright plate 2 is a first arc 25 opening downwards, and the lower surface of each upright plate 2 is a second arc 26 opening upwards. The front end of the first arc 25 intersects with the front end of the second arc 26 to form a first sharp angle 27; the rear end of the first arc 25 intersects with the rear end of the second arc 26 to form a second sharp angle 28. This arc and sharp angle design conforms to fluid dynamics, allowing water to flow smoothly along the surface of the pectoral fins, reducing turbulence and water resistance; it accurately simulates the natural shape of the bullnose ray's pectoral fins, enhancing biomimetic affinity and reducing interference with aquatic life.

[0034] like Figures 2 to 3 As shown, the drive assembly includes a rotary drive component 5, a swing arm 6, and a swing arm rotating component 7. In this embodiment, the rotary drive component 5 is a servo motor, but it can also be driven by a motor or a rotary cylinder. The servo motor is fixedly mounted on the support base 1 with screws, and its drive shaft 51 is distributed in the front-to-back direction. One end of the swing arm 6 is fixedly connected to the drive shaft 51 of the servo motor, and the other end is fixedly connected to the swing arm rotating component 7. The swing arm rotating component 7 is rotatably connected to a vertical plate 2 closest to the support base 1 in the left-to-right direction. Driven by the drive shaft 51, the connection end between the swing arm 6 and the swing arm rotating component 7 swings back and forth around the drive shaft 51 as the rotation center. This drive assembly replaces the complex structure of multiple rotary drive components, avoiding the problems of difficult coordinated control of multiple drive components and motion incoordination caused by differences in power output. It uses a single rotary drive component 5, simplifying the structure and reducing costs. Through the transmission between the swing arm 6 and the swing arm rotating component 7, the vertical plate 2 is stably oscillating, reducing control complexity, improving motion coordination, and indirectly improving swimming efficiency.

[0035] like Figure 4As shown in the figure, a flange 52 is fixedly connected to the drive shaft 51 of the rotary drive member 5 by screws; the swing arm 6 is fixedly connected to the flange 52 by screws, and the swing arm 6 rotates up and down under the drive of the drive shaft 51; a through hole 21 is horizontally penetrated through the vertical plate 2 near the support base 1; a swing arm support block 22 is arranged at the through hole 21 on the vertical plate 2. The swing arm support block 22 is in the shape of a "convex" character vertically distributed, and the protruding part in the middle of the swing arm support block 22 is inserted into the through hole 21, and the upper and lower ends of the swing arm support block 22 are fixedly arranged on the vertical plate 2 by screws. A shaft hole 221 distributed in the front and rear directions is arranged in the middle of the swing arm support block 22; a rotating shaft 71 distributed in the front and rear directions is arranged on the swing arm rotating member 7. The rotating shaft 71 is inserted into the shaft hole 221, and the rotating shaft 71 is rotationally fitted in the shaft hole 221, and the swing arm rotating member 7 is enabled to rotate in the left and right directions (the same as the rotation direction of the drive shaft 51) in the through hole 21, so as to be able to drive the first-level vertical plate 201 to move up and down and swing left and right. And when the first-level vertical plate 201 moves upward, the movement position of the first-level vertical plate 201 is the highest, so that the second-level vertical plate 202, the third-level vertical plate 203, the fourth-level vertical plate 204, and the fifth-level vertical plate 205 are respectively lowered; when the first-level vertical plate 201 moves downward, the movement position of the first-level vertical plate 201 is the lowest, so that the second-level vertical plate 202, the third-level vertical plate 203, the fourth-level vertical plate 204, and the fifth-level vertical plate 205 are respectively raised, and the overall pectoral fin structure forms a wave form along the pectoral fin span. Through the rigid cooperation of the flange 52, the swing arm support block 22, and the rotating shaft 71, the stability of the driving force transmission is enhanced, and the mechanical wear is reduced; it is ensured that the power of the driving member is efficiently transmitted to the vertical plate, the energy loss is avoided, and the service life of the equipment is prolonged.

[0036] As Figure 4 shown, swing arm support blocks 22 are arranged on both the front and rear sides of the through hole 21 on the vertical plate 2, and the shaft holes 221 on the two swing arm support blocks 22 are coaxially arranged; rotating shafts 71 are arranged on both the front and rear sides of the swing arm rotating member 7, and the rotating shafts 71 on the front and rear sides are coaxially arranged. The rotating shafts 71 on the front and rear sides are respectively rotationally fitted with the swing arm support blocks 22 on the front and rear sides. Through the above structure, the problem of asymmetric deformation on both sides of the pectoral fin caused by unilateral force in the cable drive is avoided, and the bidirectional symmetric support ensures that the vertical plate 2 is evenly stressed and there is no skew during the movement process, ensuring symmetric deformation on both sides of the pectoral fin, reducing the interference of water resistance, and improving the propulsion efficiency and attitude stability.

[0037] As Figure 4As shown, each upright plate 2 has mounting grooves 23 on its upper and lower surfaces; connecting shafts 24 distributed in a front-to-back direction are provided within the mounting grooves 23; a first flexible connecting plate 3 is rotatably connected to the upper connecting shaft 24 of each upright plate; a second flexible connecting plate 4 is rotatably connected to the lower connecting shaft 24 of each upright plate. The connection via the connecting shafts 24 allows for more flexible relative movement between the flexible connecting plates and the upright plates 2, ensuring a smooth transition during the swaying of the upright plates through the traction of the flexible connecting plates, without abrupt changes in angle, thus ensuring the continuity of the pectoral fin undulations and reducing turbulence. The outer end of the first flexible connecting plate 3 is rotatably connected to the upper connecting shaft 24 of the outermost upright plate 2; the outer end of the second flexible connecting plate 4 is rotatably connected to the lower connecting shaft 24 of the outermost upright plate 2. This avoids the problem of uncontrolled movement at the end of the pectoral fin or disconnection from the overall wave, and achieves coordinated movement across the entire range from the support base 1 to the outermost upright plate 2. This ensures that the wave-like oscillation covers the entire pectoral fin without any blind spots, further enhancing the continuity and integrity of the wave and improving propulsion efficiency.

[0038] In this embodiment, both the first flexible connecting plate 3 and the second flexible connecting plate 4 are thin plates made of nylon material, and both are elongated strips. Nylon material combines flexibility, strength, and corrosion resistance, making it suitable for underwater environments; its flexibility can meet the requirements of wave-like bending, and its wear resistance reduces mechanical wear, lowers maintenance costs, and extends service life.

[0039] like Figures 1 to 5 As shown, a fin tip plate 8 is horizontally arranged on the outer side of the outermost upright plate 2, and the fin tip plate 8 is fixedly connected to the upright plate 2 by screws. The gradually changing length design of the upright plate 2 conforms to the natural shape of the bullnose ray's pectoral fin, which is "thicker near the body and thinner at the far body". The fin tip plate 8 enhances the control of water flow at the end, reduces water resistance, and improves the guidance of the wave, making the propulsion more efficient; it also enhances the biomimetic effect and reduces interference with aquatic organisms. Furthermore, the first flexible connecting plate 3 and the second flexible connecting plate 4 are connected to the first-level upright plate 201, the second-level upright plate 202, the third-level upright plate 203, the fourth-level upright plate 204, the fifth-level upright plate 205, and the fin tip plate 8 respectively through the connecting shaft 24, forming a rotating pair and creating an active bending flexible oscillation effect.

[0040] The working process of this structure:

[0041] In the initial state, the bullnose ray-inspired underwater robot actively bends its flexible pectoral fin structure to a zero position, enabling it to float on the water surface.

[0042] When the bullnose ray-inspired underwater robot needs to swim forward, the active bending flexible pectoral fin structures on both sides move simultaneously, forming the same waveform and generating forward thrust, thereby enabling it to swim forward.

[0043] When the bullnose ray-inspired underwater robot needs to turn left, the flapping of the left-side actively curved flexible pectoral fin structure slows down, while the flapping of the right-side actively curved flexible pectoral fin structure speeds up. When it needs to turn right, the flapping of the actively curved flexible pectoral fin structure is reversed.

[0044] In the description of the embodiments of this application, it should be noted that the terms "inner" and "outer" and other terms indicating direction or positional relationship are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0045] In the description of this application, the references to terms such as "an embodiment," "some embodiments," "in this embodiment," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0046] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An actively bending flexible pectoral fin structure for use in a cownose ray-inspired underwater robot, characterized in that, It includes a support base (1), several upright plates (2), a first flexible connecting plate (3), a second flexible connecting plate (4), and a drive assembly; all the upright plates (2) are arranged at intervals in the left-right direction on one side of the support base (1), the first flexible connecting plate (3) is movably connected to the upper part of each upright plate (2), and one end of the first flexible connecting plate (3) is fixedly connected to the support base (1); the second flexible connecting plate (4) is movably connected to the lower part of each upright plate (2), and one end of the second flexible connecting plate (4) is fixedly connected to the support base (1), the drive assembly is set on the support base (1), and the upright plate (2) closest to the support base (1) is connected to the drive assembly for transmission, and under the action of the drive assembly, all the upright plates (2) swing in a wave-like manner along the pectoral fin unfolding direction.

2. The active bending flexible pectoral fin structure for the bovine-nose ray-inspired underwater robot according to claim 1, characterized in that, The drive assembly includes a rotary drive (5), a swing arm (6), and a swing arm rotating component (7); the rotary drive (5) is mounted on the support base (1), and the drive shaft (51) of the rotary drive (5) is arranged in a front-to-back direction; one end of the swing arm (6) is fixedly connected to the drive shaft (51) of the rotary drive (5), and the other end of the swing arm (6) is fixedly connected to the swing arm rotating component (7). The swing arm rotating component (7) is rotatably connected to a vertical plate (2) closest to the support base (1), and the rotation direction of the swing arm rotating component (7) is consistent with that of the drive shaft (51). Under the drive of the drive shaft (51), the connection end of the swing arm (6) and the swing arm rotating component (7) swings back and forth around the drive shaft (51) as the rotation center.

3. The active bending flexible pectoral fin structure for the bovine-nose ray-inspired underwater robot according to claim 2, characterized in that, A through hole (21) is provided on the upright plate (2) near the support base (1) in the left-right direction; a swing arm support block (22) is provided on the upright plate (2) at the through hole (21); a shaft hole (221) is provided on the swing arm support block (22) in the front-back direction; a rotating shaft (71) is provided on the swing arm rotating component (7) in the front-back direction, and the rotating shaft (71) is rotatably connected in the shaft hole (221) to realize the swing arm rotating component (7) rotating in the left-right direction in the through hole (21).

4. The active bending flexible pectoral fin structure for the bovine-nose ray-inspired underwater robot according to claim 3, characterized in that, The vertical plate (2) is symmetrically provided with the swing arm support blocks (22) on the front and rear sides of the through hole (21), and the shaft holes (221) on the two swing arm support blocks (22) are coaxially arranged; the swing arm rotating part (7) is provided with the rotating shaft (71) on both the front and rear sides, and the rotating shafts (71) on the front and rear sides are coaxially arranged; the rotating shafts (71) on the front and rear sides are respectively rotated and engaged with the shaft holes (221) on the front and rear swing arm support blocks (22).

5. The active bending flexible pectoral fin structure for the bovine-nose ray-inspired underwater robot according to claim 1, characterized in that, Each upright plate (2) has connecting shafts (24) arranged in a front-to-back direction at its upper and lower parts; the first flexible connecting plate (3) is rotatably connected to the upper connecting shaft (24) of each upright plate; the second flexible connecting plate (4) is rotatably connected to the lower connecting shaft (24) of each upright plate.

6. The active bending flexible pectoral fin structure for the bovine-nose ray-inspired underwater robot according to claim 5, characterized in that, Each of the vertical plates (2) is provided with mounting grooves (23) at the top and bottom; the connecting shafts (24) on the upper and lower sides are respectively provided in the mounting grooves (23) on the upper and lower sides.

7. The active bending flexible pectoral fin structure for the bovine-nose ray-inspired underwater robot according to claim 5, characterized in that, The outer end of the first flexible connecting plate (3) is rotatably connected to the connecting shaft (24) on the upper side of the outermost vertical plate (2); the outer end of the second flexible connecting plate (4) is rotatably connected to the connecting shaft (24) on the lower side of the outermost vertical plate (2).

8. The active bending flexible pectoral fin structure for the bovine-nose ray-inspired underwater robot according to claim 1, characterized in that, The length of all uprights (2) gradually decreases from the direction closest to the support (1) to the direction furthest from the support (1).

9. The active bending flexible pectoral fin structure for a bullnose ray-inspired underwater robot according to claim 1 or 8, characterized in that, The outer side of the farthest upright plate (2) is provided with fin tips (8) distributed in the left-right direction.

10. The active bending flexible pectoral fin structure for the bovine-nose ray-inspired underwater robot according to claim 1, characterized in that, Both the first flexible connecting plate (3) and the second flexible connecting plate (4) are thin plates made of nylon material.

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