Bionical stingray-like underwater patrol robot based on annular fin propulsion

CN224797170UActive Publication Date: 2026-09-25OCEAN UNIV OF CHINA
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Patent Information

Application Number
CN202522242115.8
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2025-10-23
Publication Date
2026-09-25
Estimated Expiration
2035-10-23

AI Technical Summary

Technical Problem

[0002]目前,通常采用水下机器人对海草床进行巡航,传统水下机器人普遍采用螺旋桨推进器,其高速旋转的叶片极易被海草、渔网等水下纤维状物体缠绕,导致机器人失效

Benefits of technology

(1)本实用新型通过环形柔性鳍的仿生波动推进替代传统螺旋桨,从根本上避免了缠绕风险,仿生波动鳍推进方式水流扰动小、噪音低,适用于对水流敏感或需隐蔽作业的环境,避免对海草或周围生态造成干扰。

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Abstract

The utility model discloses a kind of bionic flounder type underwater patrol robot based on annular fin propulsion, belong to underwater robot technical field, including waterproof shell, annular flexible fin and annular fin propulsion mechanism;Annular fin propulsion mechanism includes annular mounting plate, a plurality of first steering gears are evenly arranged on annular mounting plate along circumferential direction, the output end of first steering gear is set to extend the fin strip of annular mounting plate radial direction, and fin strip is fixedly connected with annular flexible fin;Fin strip includes the connecting seat connected with the output end of first steering gear, and the clamping jaw for clamping annular flexible fin is rotatably matched on connecting seat.The utility model replaces traditional propeller by the bionic fluctuation propulsion of annular flexible fin, fundamentally avoids the risk of winding, and bionic fluctuation fin propulsion mode is small, noise is low, suitable for the environment sensitive to water flow or needing to hide operation, avoid to cause disturbance to sea grass or surrounding ecology.
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Description

Technical Field

[0001] This utility model belongs to the field of underwater robot technology, specifically relating to a biomimetic stingray-like underwater patrol robot based on ring fin propulsion. Background Technology

[0002] Currently, underwater robots are commonly used to patrol seagrass beds. Traditional underwater robots generally use propeller propulsion, but their high-speed rotating blades are easily entangled by underwater fibrous objects such as seagrass and fishing nets, causing the robot to malfunction. At the same time, the propeller generates strong water flow disturbance (jet) and significant noise (usually ≥80 decibels) when it is working. This not only stirs up sediment, affecting the clarity of visual detection, but also disturbs marine life and disrupts the natural state of the detected target, making it unsuitable for ecological patrol scenarios that require "invisibility" operations.

[0003] Based on this, this application proposes a biomimetic stingray-like underwater patrol robot based on ring fin propulsion. By replacing the traditional propeller with biomimetic wave propulsion of ring flexible fins, the risk of entanglement is fundamentally avoided, and noise and water flow disturbance are significantly reduced. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a biomimetic stingray-like underwater patrol robot based on ring fin propulsion.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: The biomimetic stingray-like underwater patrol robot based on ring fin propulsion includes a waterproof shell, a ring flexible fin surrounding the outer circumference of the waterproof shell, and a ring fin propulsion mechanism located between the outer radial circumference of the waterproof shell and the inner radial circumference of the ring flexible fin. The annular fin propulsion mechanism includes an annular mounting plate fixedly disposed on the radially outer side of the circumference of the waterproof housing. A plurality of first servo motors are uniformly arranged on the annular mounting plate along the circumferential direction. The output end of the first servo motors is provided with fins extending along the radial direction of the annular mounting plate. The fins are fixedly connected to the annular flexible fin. The central axis of the first servo motor output end is perpendicular to the central axis of the annular mounting plate, and the central axis of the first servo motor output end is perpendicular to the length extension direction of the fin provided on the first servo motor output end; The fin includes a connecting seat connected to the output end of the first servo motor, and the connecting seat is rotatably fitted with a gripper for holding the annular flexible fin.

[0006] Preferably, the gripper is rotatably engaged with the connecting seat via a bearing.

[0007] Preferably, the gripper includes a first clamping piece and a second clamping piece, one end of the first clamping piece and the second clamping piece are fixedly connected by a clamping seat, and the clamping seat is rotatably engaged with the connecting seat; The first and second clamping plates in the gripper hold the annular flexible fin and are then fixedly connected by fastening screws.

[0008] Preferably, a binocular camera is provided on the upper part of the waterproof housing, and a second servo motor is provided on the waterproof housing to drive the binocular camera to rotate 360°.

[0009] Preferably, the waterproof housing is equipped with a water pressure sensor, a temperature sensor, a salinity sensor, a dissolved oxygen sensor, a pH sensor, and an attitude sensor.

[0010] Preferably, the waterproof housing is provided with a counterweight mechanism, which includes a counterweight block and a moving mechanism capable of driving the counterweight block to move.

[0011] Preferably, the moving mechanism includes a moving motor and a lead screw; The mobile motor is fixedly installed inside the waterproof housing, and the two ends of the lead screw are rotatably fitted on the mounting base inside the waterproof housing. One end of the lead screw is coaxially fixedly connected to the output end of the mobile motor. The bottom end of the counterweight is slidably engaged with the waterproof housing along the axial direction of the lead screw, and the middle part of the counterweight is threadedly engaged with the lead screw. The central axis of the lead screw intersects perpendicularly with the central axis of the waterproof housing.

[0012] Preferably, the waterproof housing is provided with a buoyancy mechanism, which includes a buoyancy chamber and an adjustment mechanism that can change the volume of water in the buoyancy chamber.

[0013] Preferably, one end of the submersible water chamber is an open end, and the other end is provided with a water pipe. The interior of the submersible water chamber is fitted with a piston in a sliding seal. A push plate is fixedly provided on one side of the piston, and the end of the push plate extends out of the open end of the submersible water chamber. The water pipe extends out of the waterproof shell. The adjustment mechanism is connected to the push plate, and the adjustment mechanism drives the push plate to move the piston, thereby adjusting the volume of water in the sinking and floating water chamber.

[0014] Preferably, the adjustment mechanism includes an adjustment motor, an adjustment gear, an adjustment rack, and a connecting plate; The regulating motor is fixedly installed inside the waterproof housing. The regulating gear is coaxially fixedly connected to the output shaft of the regulating motor. The regulating rack is slidably engaged with the outer wall of the submersion chamber. One end of the regulating rack is fixedly connected to the outer end of the push plate through a connecting plate. The adjusting gear is engaged with the adjusting rack for transmission.

[0015] The beneficial effects of this utility model are: (1) This utility model replaces the traditional propeller with the biomimetic wave propulsion of the ring flexible fin, which fundamentally avoids the risk of entanglement. The biomimetic wave fin propulsion method has small water flow disturbance and low noise, and is suitable for environments that are sensitive to water flow or require covert operation, avoiding interference with seaweed or the surrounding ecology.

[0016] (2) In this utility model, when each fin drives the annular flexible fin to form a wave motion, the gripper and the connecting seat rotate and cooperate, which can adapt to the extension direction of the wave motion of the annular flexible fin held by the gripper, making the wave motion of the annular flexible fin smoother.

[0017] (3) This utility model achieves underwater fixed-point hovering and pitch adjustment by setting up a counterweight mechanism and a sinking and floating mechanism, thereby improving the stability and positioning accuracy during patrol. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0019] Figure 1 This is a three-dimensional schematic diagram of the structure of the biomimetic stingray-like underwater patrol robot based on ring fin propulsion of this utility model; Figure 2 This is a schematic perspective view of the structure of this utility model with the annular flexible fin removed; Figure 3 This is a schematic top view of the structure of this utility model with the annular flexible fin removed; Figure 4 This is a schematic diagram of the counterweight mechanism and the buoyancy mechanism in this utility model; Figure 5 This is a three-dimensional schematic diagram of the gripper structure in this utility model; Figure 6 This is a schematic diagram showing the rotational engagement relationship between the gripper and the connecting seat in this utility model, which is adapted to the undulating extension direction of the annular flexible fin held by the gripper. in: 1. Waterproof shell; 2. Annular flexible fin; 3. Annular fin propulsion mechanism; 31. Annular mounting plate; 32. First servo motor; 33. Fin; 331. Connecting seat; 332. Gripper; 333. First clamping plate; 334. Second clamping plate; 335. Clamping seat; 4. Binocular camera; 41. Second servo motor; 5. Bouncing mechanism; 51. Bouncing water chamber; 52. Water pipe; 53. Push plate; 54. Adjusting motor; 55. Adjusting gear; 56. Adjusting rack; 57. Connecting plate; 6. Counterweight mechanism; 61. Counterweight block; 62. Moving motor; 63. Lead screw; 64. Mounting seat. Detailed Implementation

[0020] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0021] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0022] In this utility model, terms such as "upper", "lower", "bottom", and "top" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of the structural relationship between the various components or elements of this utility model and do not specifically refer to any component or element in this utility model. They should not be construed as limiting this utility model.

[0023] In this utility model, terms such as "connected" and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be determined according to the specific circumstances, and should not be construed as a limitation of this utility model.

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] Example 1: like Figures 1-6 As shown, the biomimetic stingray-like underwater patrol robot based on ring fin propulsion includes a waterproof shell 1, a ring flexible fin 2 surrounding the outer circumference of the waterproof shell 1, and a ring fin propulsion mechanism 3 located between the outer radial circumference of the waterproof shell 1 and the inner radial circumference of the ring flexible fin 2. The annular flexible fin 2 is a rubber film; The annular fin propulsion mechanism 3 includes an annular mounting plate 31 fixedly disposed on the radially outer side of the circumference of the waterproof housing 1. A plurality of first servo motors 32 are evenly disposed on the annular mounting plate 31 along the circumferential direction. The output end of the first servo motors 32 is provided with fin strips 33 extending along the radial direction of the annular mounting plate 31. The fin strips 33 are fixedly connected to the annular flexible fin 2. The central axis of the output end of the first servo motor 32 is perpendicular to the central axis of the annular mounting plate 31, and the central axis of the output end of the first servo motor 32 is perpendicular to the length extension direction of the fin 33 provided at the output end of the first servo motor 32. The fin 33 includes a connecting seat 331 connected to the output end of the first servo motor 32. A gripper 332 for clamping the annular flexible fin 2 is rotatably fitted on the connecting seat 331. The rotation center axis of the gripper 332 extends radially along the annular mounting plate 31, that is, the rotation center axis of the gripper 332 is perpendicular to the central axis of the output end of the first servo motor 32.

[0026] In this application, when each fin 33 drives the annular flexible fin 2 to form a wave-like motion, the gripper 332 and the connecting seat 331 rotate to match the extension direction of the positional fluctuation of the annular flexible fin 2 held by the gripper 332, such as... Figure 6 As shown, this makes the wave motion of the annular flexible fin 2 smoother.

[0027] Preferably, the gripper 332 is rotatably engaged with the connecting seat 331 via a bearing, and the central axis of the bearing extends radially along the annular mounting plate 31, that is, the rotational central axis of the bearing is perpendicular to the central axis of the output end of the first servo motor 32.

[0028] Preferably, the gripper 332 includes a first clamping piece 333 and a second clamping piece 334. One end of the first clamping piece 333 and the second clamping piece 334 are fixedly connected by a clamping seat 335, and the clamping seat 335 is rotatably engaged with the connecting seat 331. The first clamping piece 333 and the second clamping piece 334 in the gripper 332 hold the annular flexible fin 2 and then fix it in place with fastening screws.

[0029] Preferably, a binocular camera 4 is provided on the upper part of the waterproof housing 1, and a second servo motor 41 is provided on the waterproof housing 1 to drive the binocular camera 4 to rotate 360°.

[0030] The central axis of the output end of the second servo motor 41 is aligned with the central axis of the waterproof housing 1.

[0031] Preferably, the waterproof housing 1 is equipped with a water pressure sensor, a temperature sensor, a salinity sensor, a dissolved oxygen sensor, a pH sensor, and an attitude sensor, wherein the water pressure sensor, temperature sensor, salinity sensor, dissolved oxygen sensor, pH sensor, and attitude sensor are all connected to the controller.

[0032] Water pressure sensors can measure the water depth at the robot's location by monitoring water pressure. Temperature sensors, salinity sensors, dissolved oxygen sensors, and pH sensors are used to monitor relevant ecological parameters, while attitude sensors provide feedback on the robot's attitude angles.

[0033] In Example 1, the annular flexible fin 2 is a biomimetic design, with fin rays 33 arranged in a circular array. The annular flexible fin 2 covers the entire annular area, mimicking the wave-like characteristics of a stingray's pectoral fin. It achieves efficient propulsion by changing the starting position of the wave. Compared to traditional underwater robots with long fins on both sides, the annular flexible fin 2 can quickly change the direction of propulsion without adjusting the robot's body orientation.

[0034] Each fin ray 33 achieves a regular up-and-down swinging motion via the first servo motor 32, and the regular up-and-down swinging motion of all fin rays 33 causes the annular flexible fin 2 to form a macroscopic wave motion, simulating the movement pattern of the stingray's pectoral fin.

[0035] Example 2: Based on Embodiment 1, a counterweight mechanism 6 is provided inside the waterproof housing 1. The counterweight mechanism 6 includes a counterweight block 61 and a moving mechanism that can drive the counterweight block 61 to move.

[0036] Preferably, the moving mechanism includes a moving motor 62 and a lead screw 63; The mobile motor 62 is fixedly installed inside the waterproof housing 1. The two ends of the lead screw 63 are rotatably fitted on the mounting base 64 inside the waterproof housing 1. One end of the lead screw 63 is coaxially fixedly connected to the output end of the mobile motor 62. The bottom end of the counterweight 61 is slidably engaged with the waterproof housing 1 along the axial direction of the lead screw 63, and the middle part of the counterweight 61 is threadedly engaged with the lead screw 63. The central axis of the lead screw 63 intersects perpendicularly with the central axis of the waterproof housing 1.

[0037] In Example 2, the mobile motor 62 drives the lead screw 63 to rotate, causing the counterweight 61 to move linearly along the lead screw 63, thereby adjusting the robot's center of gravity and achieving pitch adjustment.

[0038] Example 3: Based on Embodiment 2, the waterproof housing 1 is provided with a floating mechanism 5. The floating mechanism 5 includes a floating water chamber 51 and an adjustment mechanism that can change the volume of water in the floating water chamber 51. By changing the volume of water in the floating water chamber 51, static and undisturbed floating adjustment can be achieved.

[0039] Preferably, one end of the submerged water chamber 51 is an open end, and the other end is provided with a water pipe 52. The interior of the submerged water chamber 51 is fitted with a piston in a sliding seal. A push plate 53 is fixedly provided on one side of the piston, and the end of the push plate 53 extends out of the open end of the submerged water chamber 51. The water pipe 52 extends out of the waterproof housing 1. The adjustment mechanism is connected to the push plate 53. The adjustment mechanism drives the push plate 53 to move the piston, thereby adjusting the volume of water in the sinking and floating water chamber 51.

[0040] Preferably, the adjustment mechanism includes an adjustment motor 54, an adjustment gear 55, an adjustment rack 56, and a connecting plate 57; The regulating motor 54 is fixedly installed inside the waterproof housing 1. The regulating gear 55 is coaxially fixedly connected to the output shaft of the regulating motor 54. The regulating rack 56 is slidably engaged with the outer wall of the submerged water chamber 51. One end of the regulating rack 56 is fixedly connected to the outer end of the push plate 53 through the connecting plate 57. The adjusting gear 55 is meshed with the adjusting rack 56 for transmission.

[0041] The adjusting motor 54 drives the adjusting gear 55 to rotate, thereby realizing the linear motion of the adjusting rack 56. When the adjusting rack 56 moves in a linear motion, it pushes the piston in the sinking and floating water chamber 51 inward through the connecting plate 57 and the push plate 53 to drain water or pulls the piston in the sinking and floating water chamber 51 outward to draw water.

[0042] A buoyancy mechanism 5 is set on each side of the counterweight mechanism 6.

[0043] In Example 3, the position of the piston in the submerged water chamber 51 is controlled by the adjustment mechanism to achieve water intake or drainage, thereby changing the overall gravity of the robot. When the gravity is equal to the buoyancy, the robot is suspended; when the gravity is greater than the buoyancy, the robot dives; and when the gravity is less than the buoyancy, the robot rises.

[0044] The biomimetic stingray-like underwater patrol robot based on ring fin propulsion in Example 3 can move forward or backward, translate left or right, turn left or right in place, ascend or descend statically, ascend or descend dynamically, ascend and descend like a jellyfish, and float with full degrees of freedom. The two ends of the robot along the axial direction of the lead screw 63 are defined as the head end and the tail end, respectively. When the head end is in front and the tail end is behind, it is moving forward; when the head end is behind and the tail end is in front, it is moving backward.

[0045] (1) Forward or backward: The central axis of the lead screw 63 and the vertical central axis of the waterproof housing 1 form the first symmetry plane. The first servo motors 32 on both sides of the first symmetry plane drive the corresponding fins 33 to swing up and down synchronously. Among the first servo motors 32 on the same side of the first symmetry plane, the phases of adjacent first servo motors 32 differ by a certain angle at the same time. Among the fins 33 on the same side of the first symmetry plane, the adjacent fins 33 are staggered according to the set phases. The swing presents an approximately sinusoidal wave. A traveling wave is generated on each side of the first symmetry plane, which can push the water flowing from the surface of the annular flexible fin 2 to the rear or front, thereby generating a forward thrust to achieve forward or a backward thrust to achieve backward.

[0046] (2) Translation to the left and then to the right: The vertical plane that is perpendicular to the first symmetry plane and passes through the vertical central axis of the waterproof shell 1 is the second symmetry plane. The first servo motors 32 on both sides of the second symmetry plane drive the corresponding fins 33 to swing up and down synchronously. Among the first servo motors 32 on the same side of the second symmetry plane, at the same time, the phases of adjacent first servo motors 32 differ by a certain angle. Among the fins 33 on the same side of the second symmetry plane, adjacent fins 33 are staggered according to the set phases, and the swing presents an approximately sinusoidal wave. A traveling wave is generated on each side of the second symmetry plane, which can push the water flowing from the surface of the annular flexible fin 2 to the right or left, thereby generating a leftward thrust to achieve translation to the left or generating a rightward thrust to achieve translation to the right.

[0047] (3) Turn left or turn right in place: The first servo motor 32 on the right side of the first symmetrical plane executes the forward mode and the first servo motor 32 on the left side executes the backward mode to achieve a left turn in place; the first servo motor 32 on the left side of the first symmetrical plane executes the forward mode and the first servo motor 32 on the right side executes the backward mode to achieve a right turn in place.

[0048] (4) Static rising or falling: The adjustment mechanism controls the position of the piston in the sinking and floating water chamber 51 to achieve water intake, increase the weight of the robot, and sink the robot to achieve falling; the adjustment mechanism controls the position of the piston in the sinking and floating water chamber 51 to achieve water drainage, reduce the weight of the robot, and achieve static rising of the robot.

[0049] (5) Dynamic ascent or descent: The moving motor 62 drives the lead screw 63 to rotate, causing the counterweight 61 to move linearly along the lead screw 63, adjusting the robot's center of gravity; when the center of gravity is close to the tail end of the robot, the tail end of the robot swings downward and the head end tilts upward. If the fins 33 are driven to swing in the forward mode, the robot can move upward along the inclined path. If the fins 33 are driven to swing in the backward mode, the robot can move downward along the inclined path. When the center of gravity is close to the head end of the robot, the head end of the robot swings downward and the tail end tilts upward. If the fins 33 are driven to swing in the forward mode, the robot can move downward along the inclined path. If the fins 33 are driven to swing in the backward mode, the robot can move upward along the inclined path.

[0050] (6) Jellyfish-style ascent and descent: All first servo motors 32 simultaneously and in phase swing the fins 33 downwards rapidly, causing the annular flexible fins 2 to contract rapidly, spraying water out from below in clusters to achieve ascent. In one ascent action, all first servo motors 32 simultaneously and in phase swing the fins 33 upwards slowly. After reaching the preset position, the next ascent action is performed. It is a pulse jet ascent method similar to that of a jellyfish. Descent and ascent are reversed.

[0051] (7) Fully free-floating In the forward or backward, left or right translation, and left or right turn modes, the maximum upward swing position of each first servo motor 32 is consistent, and the maximum downward swing position of each fin 33 is consistent, meaning that the swing bisectors of the swing range of each fin 33 are located on the same horizontal plane.

[0052] In the full-degree-of-freedom floating mode, several symmetrical bisecting planes are defined to divide all the first servo motors 32 into two symmetrically distributed parts. For any one of these symmetrical bisecting planes, the phase angles corresponding to the maximum upward swing position of the first servo motor 32 on the same side of the symmetrical bisecting plane are in an arithmetic sequence along the circumference, and the phase angles corresponding to the downward swing position are also in an arithmetic sequence along the circumference. That is, the swing bisecting planes of the swing range of each fin 33 are no longer located on the same horizontal plane, but rise or fall sequentially along the circumference, with the angle range of each fin 33 swinging up and down being equal. Among the first servo motors 32 on the same side of the symmetrical bisecting plane, at the same moment, the phases of adjacent first servo motors 32 differ by a certain angle, while among the fins 33 on the same side of the symmetrical bisecting plane, adjacent fins 33 are staggered sequentially according to the set phases, and the swing presents an approximately sinusoidal wave-like fluctuation. A series of obliquely upward traveling waves are generated on each side of the symmetrical bisecting plane, driving the robot to rise along an obliquely upward angle. When all the first servo motors 32 move in opposite directions, forming a reverse traveling wave, the robot can move diagonally downwards. The direction of the upward or downward movement is parallel to the symmetrical bisecting plane.

[0053] For each symmetrical bisecting plane, a tilting motion direction parallel to that symmetrical bisecting plane can be generated, thus enabling dynamic floating and sinking with full degrees of freedom in multiple directions.

[0054] When patrolling seagrass beds, the robot described in this application achieves highly maneuverable and low-disturbance underwater movement by switching between the aforementioned various motion modes. Its onboard temperature, salinity, dissolved oxygen, and pH sensors can collect ecological parameters in real time, while its binocular camera 4 captures corresponding images and uploads them to a host computer, providing data support for subsequently determining the health status and trends of the seagrass in the area.

[0055] In this application, the annular flexible fin 2 is a biomimetic wave fin. The biomimetic wave fin propulsion method has small water flow disturbance and low noise, and is suitable for environments that are sensitive to water flow or require covert operation, so as to avoid disturbing seaweed or the surrounding ecology. This utility model realizes underwater fixed-point hovering and pitch adjustment through the setting of counterweight mechanism 6 and buoyancy mechanism 5, thereby improving the stability and positioning accuracy during patrol.

[0056] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, they are not intended to limit the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the protection scope of the present utility model.

Claims

1. A biomimetic stingray-like underwater patrol robot based on ring-shaped fin propulsion, characterized in that, It includes a waterproof housing, an annular flexible fin surrounding the outer circumference of the waterproof housing, and an annular fin propulsion mechanism located between the outer radial side of the waterproof housing circumference and the inner radial side of the annular flexible fin circumference. The annular fin propulsion mechanism includes an annular mounting plate fixedly disposed on the radially outer side of the circumference of the waterproof housing. A plurality of first servo motors are uniformly arranged on the annular mounting plate along the circumferential direction. The output end of the first servo motors is provided with fins extending along the radial direction of the annular mounting plate. The fins are fixedly connected to the annular flexible fin. The central axis of the first servo motor output end is perpendicular to the central axis of the annular mounting plate, and the central axis of the first servo motor output end is perpendicular to the length extension direction of the fin provided on the first servo motor output end; The fin includes a connecting seat connected to the output end of the first servo motor, and the connecting seat is rotatably fitted with a gripper for holding the annular flexible fin.

2. The biomimetic stingray-like underwater patrol robot based on ring fin propulsion as described in claim 1, characterized in that, The gripper rotates with the connecting seat via a bearing.

3. The biomimetic stingray-like underwater patrol robot based on ring fin propulsion as described in claim 2, characterized in that, The gripper includes a first clamping piece and a second clamping piece. One end of the first clamping piece and the second clamping piece are fixedly connected by a clamping seat. The clamping seat is rotatably engaged with the connecting seat. The first and second clamping plates in the gripper hold the annular flexible fin and are then fixedly connected by fastening screws.

4. The biomimetic stingray-like underwater patrol robot based on ring fin propulsion as described in claim 1, characterized in that, The upper part of the waterproof housing is equipped with a binocular camera, and the waterproof housing is equipped with a second servo motor for driving the binocular camera to rotate 360°.

5. The biomimetic stingray-like underwater patrol robot based on ring fin propulsion as described in claim 1, characterized in that, The waterproof housing is equipped with a water pressure sensor, a temperature sensor, a salinity sensor, a dissolved oxygen sensor, a pH sensor, and an attitude sensor.

6. The biomimetic stingray-like underwater patrol robot based on ring fin propulsion as described in claim 1, characterized in that, The waterproof housing is equipped with a counterweight mechanism, which includes a counterweight block and a moving mechanism capable of driving the counterweight block to move.

7. The biomimetic stingray-like underwater patrol robot based on ring fin propulsion as described in claim 6, characterized in that, The moving mechanism includes a moving motor and a lead screw; The mobile motor is fixedly installed inside the waterproof housing, and the two ends of the lead screw are rotatably fitted on the mounting base inside the waterproof housing. One end of the lead screw is coaxially fixedly connected to the output end of the mobile motor. The bottom end of the counterweight is slidably engaged with the waterproof housing along the axial direction of the lead screw, and the middle part of the counterweight is threadedly engaged with the lead screw. The central axis of the lead screw intersects perpendicularly with the central axis of the waterproof housing.

8. The biomimetic stingray-like underwater patrol robot based on ring fin propulsion as described in claim 1, characterized in that, The waterproof housing is equipped with a buoyancy mechanism, which includes a buoyancy chamber and an adjustment mechanism that can change the volume of water in the buoyancy chamber.

9. The biomimetic stingray-like underwater patrol robot based on ring fin propulsion as described in claim 8, characterized in that, One end of the submersible water chamber is open, and the other end is equipped with a water pipe. The interior of the submersible water chamber is fitted with a piston in a sliding seal. A push plate is fixedly installed on one side of the piston, and the end of the push plate extends out of the open end of the submersible water chamber. The water pipe passes through the waterproof shell. The adjustment mechanism is connected to the push plate, and the adjustment mechanism drives the push plate to move the piston, thereby adjusting the volume of water in the sinking and floating water chamber.

10. The biomimetic stingray-like underwater patrol robot based on ring fin propulsion as described in claim 9, characterized in that, The adjustment mechanism includes an adjustment motor, an adjustment gear, an adjustment rack, and a connecting plate; The regulating motor is fixedly installed inside the waterproof housing. The regulating gear is coaxially fixedly connected to the output shaft of the regulating motor. The regulating rack is slidably engaged with the outer wall of the submersion chamber. One end of the regulating rack is fixedly connected to the outer end of the push plate through a connecting plate. The adjusting gear is engaged with the adjusting rack for transmission.