A caudal fin deformation clamping and swimming compatible bionic robotic fish

Abstract

The application discloses a tail fin deformation clamping and swimming compatible bionic robotic fish, and belongs to the underwater robot field. The bionic robotic fish comprises a fish body head, a fish body middle segment and a fish body tail fin. The fish body middle segment comprises a front part pitching adjusting mechanism and a multi-joint tail wagging mechanism. The front part pitching adjusting mechanism realizes fish body pitching angle adjustment, and the multi-joint tail wagging mechanism drives the fish body tail fin to swing. The fish body tail fin comprises a left tail fin piece, a right tail fin piece and a tail fin clamping module. The tail fin clamping module drives the left tail fin piece and the right tail fin piece to open or close. In the open state, the left tail fin piece and the right tail fin piece form a wrapping clamping space, thereby realizing clamping of a target object. In the closed state, the left tail fin piece and the right tail fin piece jointly form a complete tail fin shape, thereby providing propelling and steering power. The application realizes tail fin deformation clamping on the basis of maintaining complete bionic fish shape by fusing the clamping structure with the tail fin, and improves the concealment, proximity and operation adaptability of the bionic robotic fish.

Description

Technical Field

[0001] This invention belongs to the field of underwater robots, specifically relating to a biomimetic robotic fish that is compatible with tail fin deformation for gripping and swimming. Background Technology

[0002] Bionic robotic fish are underwater robots that can mimic the shape and swimming style of fish. They are widely used in underwater environmental monitoring, target detection, sample acquisition, and operations in complex waters. They can replace or assist humans in entering dangerous or inaccessible underwater environments to perform tasks, greatly improving the efficiency and safety of underwater operations.

[0003] Existing biomimetic robotic fish are typically designed with swimming as their core function. When they need to perform underwater grasping tasks, they often use an additional independent gripper mechanism on the front or outside of the fish's body. While this approach can accomplish the grasping action, the independent gripping mechanism usually disrupts the original fish-like shape of the biomimetic robotic fish, increasing its overall size and underwater drag, reducing its stealth and accessibility in the water, making it difficult to conduct close-range observation or operations without disturbing natural fish schools. Furthermore, after grasping the target object, the existing gripping structure often struggles to maintain its tail propulsion function, thus affecting the robotic fish's ability to continue swimming after grasping the object.

[0004] Therefore, if a biomimetic robotic fish with deformable tail fin that can be used for both gripping and swimming is proposed, and the gripping structure can be integrated with the tail fin body to achieve underwater gripping while maintaining the complete biomimetic fish shape, and still have a certain swimming ability after gripping the target object, then the shortcomings of existing biomimetic robotic fish in that it is difficult to balance gripping and swimming functions can be overcome, and the adaptability and execution ability of biomimetic robotic fish in the face of complex underwater tasks and environments can be improved. Summary of the Invention

[0005] To address the problems in the prior art, this invention proposes a biomimetic robotic fish that combines tail fin deformation for gripping and swimming. By designing the tail fin as a deformable gripping structure, the biomimetic robotic fish can maintain the complete shape of a biomimetic fish while possessing underwater gripping capabilities, and retain a certain swimming ability after gripping the target object.

[0006] This invention discloses a biomimetic robotic fish that is compatible with tail fin deformation clamping and swimming. The biomimetic robotic fish has a chain structure, including a fish head, a fish middle section and a fish tail fin arranged from front to back.

[0007] Electronic components are housed inside the fish's head, which provides a dry environment for these components.

[0008] The middle section of the fish body includes a front pitch adjustment mechanism and a multi-joint tail swing mechanism. The front pitch adjustment mechanism is installed at the rear end of the fish head and is used to adjust the pitch angle of the rear structure of the bionic robotic fish relative to the front structure. The multi-joint tail swing mechanism is connected to the rear end of the front pitch adjustment mechanism. When the multi-joint tail swing mechanism is working, it swings left and right, thereby driving the tail fin of the fish to swing.

[0009] The fish's caudal fin includes a left caudal fin plate, a right caudal fin plate, and a caudal fin gripping module. The left and right caudal fin plates are positioned separately and open or close relative to each other under the drive of the caudal fin gripping module. In the open state, the left and right caudal fin plates form an enveloping gripping space to grip the target object. In the closed state, the left and right caudal fin plates together form the complete caudal fin shape and swing left and right under the drive of the multi-joint tail-swinging mechanism, providing propulsion and steering power. The caudal fin gripping module is fixed inside the end of the middle section of the fish body and connects the front ends of the left and right caudal fin plates. The caudal fin gripping module includes a gripping drive servo and a linkage mechanism. The gripping drive servo is connected to the left and right caudal fin plates respectively through the linkage mechanism. The output torque of the gripping drive servo drives the linkage mechanism to move, causing the left and right caudal fin plates to open or close relative to each other.

[0010] This invention also provides an underwater gripping and release method for a biomimetic robotic fish based on the aforementioned tail fin deformation gripping and swimming compatibility, comprising the following steps:

[0011] S1. The multi-joint tail-swinging mechanism swings left and right, causing the left and right tail fins to swing left and right, achieving propulsion and turning, so that the bionic robotic fish can approach the target and hover to one side of the target.

[0012] S2. The clamping drive servo rotates forward and drives the left and right tail fins to open relative to each other through the linkage mechanism so as to cover the target.

[0013] S3. The front pitch adjustment mechanism adjusts the pitch angle of the rear structure of the bionic robotic fish relative to the front structure, so that the target object can accurately enter the enveloping clamping space between the left and right tail fins.

[0014] S4. The gripping drive servo reverses and drives the left and right tail fins to gradually close through the linkage mechanism until a stable gripping of the target is formed. At this time, the gripping drive servo maintains the relative position of the left and right tail fins through its own holding torque. Then the front pitch adjustment mechanism restores the pitch angle of the rear structure relative to the front structure to the initial state.

[0015] S5. The multi-joint tail-wagging mechanism swings left and right, driving the bionic robotic fish to swim to the release position;

[0016] S6. The gripping drive servo rotates forward, driving the left and right tail fins to open relative to each other and release the target; then the gripping drive servo rotates in reverse, driving the left and right tail fins to close completely, completing one gripping task.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) Compared with existing bionic robotic fish that use independent gripper mechanisms, this invention integrates the gripping structure with the tail fin body. When not performing gripping actions, the whole bionic fish shape is maintained and there are no protruding special gripping parts, thus providing better underwater concealment and target approach.

[0019] (2) Compared with the existing underwater gripping methods, the present invention uses left and right separate tail fin plates and connecting rod mechanism to realize tail fin deformation gripping, and realizes the gripping function through tail fin deformation; compared with the scheme of setting independent gripping mechanism, the overall structure of the present invention is more compact, and the left and right tail fin plates can still maintain a large water-facing area after gripping, which is more conducive to the bionic robotic fish continuing to maintain swimming ability after gripping the target object.

[0020] (3) The bionic robotic fish proposed in this invention can perform the gripping and transfer of underwater targets while maintaining the conventional swimming function, and can be combined with the front pitch adjustment mechanism for attitude fine adjustment, which improves the bionic robotic fish’s adaptability and execution ability in the face of complex grasping tasks and environments. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the overall structure of an embodiment of the present invention after removing the middle outer shell;

[0023] Figure 3 This is an exploded structural diagram of an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the tail fin gripping module structure according to an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the movement according to an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the front pitch adjustment mechanism in an embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of the pitch adjustment guide rail module structure according to an embodiment of the present invention;

[0028] Figure 8 This is an exploded view of the waterproof core compartment and its internal modules according to an embodiment of the present invention.

[0029] In the diagram, 1 is the head shell, 2 is the integrated curved rack and pinion limit slider, 3 is the first tail swing joint shell, 4 is the second tail swing joint shell, 5 is the left tail fin, 6 is the right tail fin, 7 is the waterproof core compartment, 8 is the pitch drive pinion, 9 is the pitch drive servo, 10 is the first tail swing drive servo, 11 is the first tail swing drive rocker arm, 12 is the second tail swing drive servo, 13 is the second tail swing drive rocker arm, 14 is the gripping drive servo, 15 is the gripping drive rocker arm, 16 is the first gripping drive linkage, 17 is the second gripping drive linkage, 18 is the pitch adjustment guide rail module, 19 is the battery, 20 is the inertial measurement unit, 21 is the main control board, 22 is the mounting hole for the pitch drive servo, 23 is the wiring channel for each drive servo, and 24 is the XT-90 interface. Detailed Implementation

[0030] The present invention will be further described and illustrated below with reference to specific embodiments. The embodiments described are merely examples of the content of this disclosure and do not limit the scope of the invention. The technical features of each embodiment in the present invention can be combined accordingly, provided that there is no mutual conflict.

[0031] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this embodiment of the invention are only used to explain the relative positional relationship and movement of the components in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicator will also change accordingly. In this embodiment, the direction of the fish head is considered front, and the direction of the fish tail is considered back.

[0032] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] This invention provides a biomimetic robotic fish that is compatible with tail fin deformation gripping and swimming. By integrating the gripping structure with the tail fin body, the biomimetic robotic fish does not need to be equipped with an additional protruding independent gripper mechanism, thus maintaining good concealment during task execution.

[0034] Figure 1 This invention presents a schematic diagram of the overall structure of the biomimetic robotic fish proposed in this invention. Figure 3 An exploded structural diagram of an embodiment of the present invention is shown. As shown in the figure, the biomimetic robotic fish includes a head, a tail fin, and a midsection of the body between the head and the tail fin.

[0035] The fish's head is composed of a head shell 1, which is assembled from multiple irregularly shaped plates. Inside the head shell 1 is a waterproof core compartment 7, which is used to house electronic components and provide a dry environment.

[0036] The fish's caudal fin consists of a left caudal fin plate 5 and a right caudal fin plate 6. When performing a gripping task, the left caudal fin plate 5 and the right caudal fin plate 6 can open and cover the target object under the drive system to achieve the gripping function; when there is no task, they close, and in the closed state, they together form a complete biomimetic caudal fin shape and provide swimming power.

[0037] The middle section of the fish's body includes the middle shell and the drive system inside the middle shell.

[0038] like Figure 2 and Figure 3 The drive system inside the mid-section outer shell includes a pitch drive pinion 8, a pitch drive servo 9, a tail yaw drive module, and a tail fin gripping module. The tail yaw drive module includes a first tail yaw drive servo 10, a first tail yaw drive rocker arm 11, a second tail yaw drive servo 12, and a second tail yaw drive rocker arm 13. The tail fin gripping module includes a gripping drive servo 14 and a linkage mechanism. The pitch drive servo 9 is fixedly mounted at the rear end of the waterproof core compartment 7, and the first tail yaw drive servo 10 is fixedly mounted at the rear end of the pitch drive servo 9. Both the first tail yaw drive rocker arm 11 and the second tail yaw drive rocker arm 13 are U-shaped rocker arms. The open end of the first tail yaw drive rocker arm 11 is connected to the upper output shaft of the first tail yaw drive servo 10 and the lower end of the first tail yaw drive servo 10, respectively, and the closed end of the first tail yaw drive rocker arm 11 is the actuator end. The relationship between the second tail-swing drive servo 12 and the second tail-swing drive rocker arm 13 is the same as that between the first tail-swing drive servo 10 and the first tail-swing drive rocker arm 11, and the second tail-swing drive servo 12 is fixedly installed at the closed end of the first tail-swing drive rocker arm 11. The clamping drive servo 14 is fixedly installed at the closed end of the second tail-swing drive rocker arm 13. The clamping drive servo 14 is connected to the left tail fin 5 and the right tail fin 6 through a linkage mechanism, thereby controlling the opening and closing of the left tail fin 5 and the right tail fin 6 to achieve the clamping function.

[0039] The mid-section shell, from front to back, includes a pitch adjustment guide rail module 18, a curved rack and pinion slider integrated component 2, a first tail swing joint shell 3, and a second tail swing joint shell 4. Together with the head shell 1, left tail fin 5, and right tail fin 6, the mid-section shell provides a biomimetic fish shape and optimizes fluid dynamics. The pitch adjustment guide rail module 18 is fixedly fitted to the outside of the pitch drive servo 9, the curved rack and pinion slider integrated component 2 is fixedly fitted to the outside of the first tail swing drive servo 10, the first tail swing joint shell 3 is fixedly fitted to the outside of the second tail swing drive servo 12, and the second tail swing joint shell 4 is fixedly fitted to the outside of the clamping drive servo 14, thus forming a multi-jointed mid-section of the fish body. Meanwhile, the closed end of the first tail-swinging drive rocker arm 11 is located in the first tail-swinging joint housing 3, thereby causing the first tail-swinging joint housing 3 to swing; the closed end of the second tail-swinging drive rocker arm 13 is located in the second tail-swinging joint housing 4, thereby causing the second tail-swinging joint housing 4 to swing; thus, the coordinated biomimetic swinging of the first tail-swinging joint housing 3 and the second tail-swinging joint housing 4 drives the tail fin of the fish to swing, providing power support for the swimming of the biomimetic robotic fish.

[0040] The tail fin gripping module and the fish's tail fin are the core gripping mechanisms of this invention, such as... Figure 4 The diagram illustrates the tail fin gripping module and the fish tail fin structure according to an embodiment of the present invention. The left tail fin 5 and right tail fin 6 are positioned separately, forming a complete tail fin shape when closed. The gripping drive rocker arm 15 is connected to the output shaft of the gripping drive servo motor 14; one end of the first gripping drive linkage 16 is connected to the gripping drive rocker arm 15, and the other end is connected to the upper front end of the right tail fin 6; one end of the second gripping drive linkage 17 is connected to the gripping drive rocker arm 15, and the other end is connected to the lower front end of the left tail fin 5, thus forming the linkage mechanism of the tail fin gripping module.

[0041] In this embodiment, the clamping drive servo motor 14 outputs torque to drive the clamping drive rocker arm 15 to rotate, which in turn drives the first clamping drive linkage 16 and the second clamping drive linkage 17 to move, causing the left tail fin 5 and the right tail fin 6 to open or close relative to each other. Since the left and right tail fins deform synchronously under the drive of the linkage mechanism, when clamping the target object, the left tail fin 5 and the right tail fin 6 can jointly form an enveloping clamping space to achieve clamping of the target object. Specifically, when performing the clamping task, the clamping drive servo 14 rotates forward, driving the first clamping drive linkage 16 and the second clamping drive linkage 17 to rotate forward via the clamping drive rocker arm 15. This drives the left tail fin 5 and the right tail fin 6 to open relative to each other until they can cover the target object. Subsequently, the clamping drive servo 14 rotates in reverse, driving the first clamping drive linkage 16 and the second clamping drive linkage 17 to rotate in the opposite direction via the clamping drive rocker arm 15. This drives the left tail fin 5 and the right tail fin 6 to gradually close until a stable clamping of the target object is formed. At this time, the clamping drive servo 14 maintains the relative position of the left tail fin 5 and the right tail fin 6 through its own holding torque. When releasing the target object, the clamping drive servo 14 rotates forward to drive the left tail fin 5 and the right tail fin 6 to open relative to each other, releasing the target object. Subsequently, the clamping drive servo 14 rotates in reverse to drive the left tail fin 5 and the right tail fin 6 to close completely.

[0042] Furthermore, the left caudal fin plate 5 and the right caudal fin plate 6 maintain the caudal fin shape characteristics during the opening and closing process. When not performing a clamping task, the overall structure maintains the complete bionic fish tail shape and there is no independent exposed special gripper mechanism. Therefore, it is beneficial to improve the concealment and accessibility of the bionic robotic fish when approaching the target to be clamped.

[0043] like Figure 5 The diagram illustrates the swimming motion of an embodiment of the present invention. During swimming, the bionic robotic fish uses a first tail-swinging drive servo 10 and a second tail-swinging drive servo 12 to drive the first tail-swinging drive rocker arm 11 and the second tail-swinging drive rocker arm 13, respectively. This, in turn, drives the first tail-swinging joint housing 3 and the second tail-swinging joint housing 4, causing the fish's tail fin to swing left and right, achieving propulsion and steering. When the aforementioned tail fin gripping module is in an ungripped state, the left tail fin plate 5 and the right tail fin plate 6 close to form a complete tail fin, and its swinging pattern is consistent with that of a conventional bionic robotic fish tail fin.

[0044] It should be noted that after the left caudal fin 5 and right caudal fin 6 grasp the target, although the caudal fin cannot fully return to a closed state, the biomimetic robotic fish still possesses a certain swimming ability due to the large surface area exposed to water on both sides, driven by the tail wagging action. This swimming ability can be used for short-distance transfer, posture adjustment, or withdrawal after grasping the target, thus achieving compatibility between caudal fin grasping and swimming.

[0045] The curved rack and pinion limit slider integrated component 2, the pitch drive pinion 8, the pitch drive servo motor 9, and the pitch adjustment guide rail module 18 together constitute the front pitch adjustment mechanism of the present invention. Figure 6 A schematic diagram of the front pitch adjustment mechanism according to an embodiment of the present invention is shown. Figure 7 A schematic diagram of the pitch adjustment guide rail module structure according to an embodiment of the present invention is shown. As shown, the front end of the pitch adjustment guide rail module 18 is fixedly connected to the head shell 1. The rear end face of the pitch adjustment guide rail module 18 is provided with a concave curved guide rail, and the front end face of the curved rack limiting slider integral component 2 is provided with a protruding curved rack. The curved rack and the curved guide rail cooperate with each other to restrict the movement of the curved rack limiting slider integral component 2 within the range of the drive guide rail. The pitch drive pinion 8 is connected to the output shaft of the pitch drive servo 9 and rotates synchronously with the output shaft of the pitch drive servo 9. The pitch drive pinion 8 meshes with the curved rack on the front end face of the curved rack limiting slider integral component 2. When the front pitch adjustment mechanism is working, the pitch drive servo 9 drives the pitch drive pinion 8 to rotate, causing the curved rack limit slider integrated piece 2 to move relative to the pitch adjustment guide rail module 18 along the curved guide rail, thereby changing the angle between the front and rear structures of the fish body, and realizing the pitch adjustment of the rear of the bionic robotic fish relative to the front structure.

[0046] During the gripping task, when the front pitch adjustment mechanism is activated, the overall posture of the bionic robotic fish can be finely adjusted, making it easier for the target object to be gripped to enter the gripping area between the left tail fin 5 and the right tail fin 6, thereby assisting in the completion of the tail fin gripping action. However, in this invention, the front pitch adjustment mechanism is an auxiliary adjustment structure and does not change the basic concept of the tail fin gripping module as the core gripping mechanism.

[0047] It should be noted that in the biomimetic robotic fish, the front pitch adjustment, tail wagging drive, and tail fin clamping are driven by different servos, which are decoupled and independent degrees of freedom from each other. Specifically, the pitch drive servo 9 is used to control the pitch of the rear of the fish relative to the front, the first tail wagging drive servo 10 and the second tail wagging drive servo 12 are used to control the tail wagging, and the clamping drive servo 14 is used to control the opening and closing of the left tail fin 5 and the right tail fin 6. Each drive action does not interfere with the others.

[0048] like Figure 8The diagram shows an exploded view of the waterproof core compartment 7 and its internal modules according to an embodiment of the present invention. The biomimetic robotic fish of the present invention contains a main control module, a power supply module, and a sensing module. The waterproof core compartment 7 houses the main control module, the power supply module, and the sensing module, thereby providing a dry and sealed working environment for the non-waterproof electronic components. The rear end of the waterproof core compartment 7 is provided with pitch drive servo mounting holes 22, wiring channels 23 for each drive servo, and an XT-90 interface 24. The pitch drive servo mounting holes 22 are used to install the pitch drive servo 9, the wiring channels 23 are used for routing the servo wires, and the XT-90 interface 24 is used for power supply connection.

[0049] In this embodiment, the power supply module includes a battery 19 for powering the bionic robotic fish; the sensing module includes an inertial measurement unit 20 for collecting the attitude information of the bionic robotic fish and transmitting the attitude information to the main control module; the main control module includes a main control board 21, which is responsible for the coordination and management between the modules, and processes the attitude data and sends control signals to the pitch drive servo 9, the first tail swing drive servo 10, the second tail swing drive servo 12 and the gripping drive servo 14, thereby realizing the coordinated control of the bionic robotic fish's front pitch adjustment, tail swing swimming and tail fin gripping actions.

[0050] This invention also provides an underwater gripping method for a biomimetic robotic fish based on the above-mentioned tail fin deformation gripping and swimming compatibility, comprising the following steps:

[0051] S1. The main control module sends control signals to the first tail-swinging drive servo motor 10 and the second tail-swinging drive servo motor 12 according to the position of the target object to be gripped. The first tail-swinging drive servo motor 10 and the second tail-swinging drive servo motor 12 drive the first tail-swinging joint housing 3 and the second tail-swinging joint housing 4 to move through the first tail-swinging drive rocker arm 11 and the second tail-swinging drive rocker arm 13, respectively, so that the fish tail swings left and right to achieve propulsion and turning, thereby making the bionic robotic fish approach the target object and hover above or below the target object.

[0052] S2. The main control module sends a control signal to the gripping drive servo motor 14 to control its forward rotation. The gripping drive servo motor 14 drives the left tail fin 5 and the right tail fin 6 to open relative to each other to cover the target object through the gripping drive rocker arm 15, the first gripping drive linkage 16 and the second gripping drive linkage 17.

[0053] S3. The sensing module collects the posture information of the bionic robotic fish and transmits it to the main control module. The main control module analyzes the posture information and the position of the target object, and sends a control signal to the pitch drive servo motor 9. The pitch drive servo motor 9 drives the pitch drive pinion 8 to rotate, thereby driving the curved rack limit slider integrated piece 2 to move relative to the pitch adjustment guide rail module 18, realizing the pitch adjustment of the rear of the bionic robotic fish, so that the target object can accurately enter the clamping area between the left tail fin 5 and the right tail fin 6.

[0054] S4. The main control module sends a control signal to the gripping drive servo 14 to control its reversal, driving the left tail fin 5 and the right tail fin 6 to gradually close until a stable grip is formed on the target. At this time, the gripping drive servo 14 maintains the relative position of the left tail fin 5 and the right tail fin 6 through its own holding torque. Then the main control module sends a control signal to the pitch drive servo 9 to drive the curved rack limit slider integrated piece 2 back to the initial position.

[0055] S5. The main control module sends control signals to the first tail-swinging drive servo motor 10 and the second tail-swinging drive servo motor 12 to drive the bionic robotic fish to swim to the release position.

[0056] S6. The main control module sends a control signal to the gripping drive servo 14 to control its forward rotation, driving the left tail fin 5 and the right tail fin 6 to open relative to each other and release the target object; then the gripping drive servo 14 reverses to drive the left tail fin 5 and the right tail fin 6 to close completely, completing one gripping task.

[0057] During the mission, if it is necessary to adjust the height of the bionic robotic fish, the swimming angle can be adjusted through the front pitch mechanism.

[0058] In summary, this invention constructs the left and right caudal fin plates 5 and 6 into an openable and deformable caudal fin clamping structure, enabling the bionic robotic fish to achieve underwater clamping while maintaining a complete bionic fish shape. Simultaneously, combined with an independent tail-wagging drive module, the bionic robotic fish retains a certain swimming ability after clamping the target object. Furthermore, the front pitch adjustment mechanism allows for auxiliary attitude fine-tuning during the clamping process, thereby improving the bionic robotic fish's grasping adaptability and operational capabilities in complex underwater environments. The bionic robotic fish with deformable caudal fin clamping and swimming compatibility provided by this invention possesses excellent underwater concealment characteristics and target approach capabilities, significantly improving its adaptability and execution efficiency in complex grasping tasks and changing environments.

[0059] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A biomimetic robotic fish with a deformable tail fin that allows for both gripping and swimming, characterized in that, The biomimetic robotic fish has a chain structure, including a head, a middle section of the body, and a tail fin arranged from front to back. Electronic components are housed inside the fish's head, which provides a dry environment for these components. The midsection of the fish's body includes a front pitch adjustment mechanism and a multi-joint tail-wagging mechanism. The front pitch adjustment mechanism is installed at the rear end of the fish's head and includes a curved rack and pinion slider assembly, a pitch drive pinion, a pitch drive servo, and a pitch adjustment guide module. The front end of the curved rack and pinion slider assembly has a protruding curved rack that meshes with the pitch drive pinion. The pitch drive pinion is connected to the output shaft of the pitch drive servo and rotates synchronously with the output shaft of the pitch drive servo. The pitch drive servo is fixedly installed at the rear end of the fish's head. When the pitch drive servo is working, it drives the pitch drive pinion to rotate. This drives the integrated curved rack and pinion slider to rotate around the pitch drive pinion, thereby adjusting the pitch angle of the rear structure of the bionic robotic fish relative to the front structure. The front end of the pitch adjustment guide rail module is fixedly installed at the rear end of the fish's head. The rear end face of the pitch adjustment guide rail module has a concave curved guide rail, which matches the curved rack on the front end face of the integrated curved rack and pinion slider, providing guidance for the rotation of the integrated curved rack and pinion slider. The multi-joint tail swing mechanism is connected to the rear end of the front pitch adjustment mechanism. When the multi-joint tail swing mechanism is working, it swings left and right, thereby driving the tail fin of the fish to swing. The fish's caudal fin includes a left caudal fin plate, a right caudal fin plate, and a caudal fin gripping module. The left and right caudal fin plates are positioned separately and open or close relative to each other under the drive of the caudal fin gripping module. In the open state, the left and right caudal fin plates form an enveloping gripping space to grip the target object. In the closed state, the left and right caudal fin plates together form the complete caudal fin shape and swing left and right under the drive of the multi-joint tail-swinging mechanism, providing propulsion and steering power. The caudal fin gripping module is fixed inside the end of the middle section of the fish body and connects the front ends of the left and right caudal fin plates. The caudal fin gripping module includes a gripping drive servo motor. The linkage mechanism includes a clamping drive rocker arm, a first clamping drive link, and a second clamping drive link. The clamping drive rocker arm is connected to the output shaft of the clamping drive servo motor. One end of the first clamping drive link is connected to the clamping drive rocker arm, and the other end is connected to the upper front end of the right tail fin. One end of the second clamping drive link is connected to the clamping drive rocker arm, and the other end is connected to the lower front end of the left tail fin. The clamping drive servo motor outputs torque to drive the clamping drive rocker arm to rotate, which in turn drives the first and second clamping drive links to rotate in the same direction, thereby causing the left and right tail fins to open or close relative to each other.

2. The biomimetic robotic fish with tail fin deformation and gripping compatible with swimming as described in claim 1, characterized in that, The tail fin gripping module achieves gripping and releasing of the target object through a gripping drive servo motor and linkage mechanism; During the clamping process, the clamping drive servo rotates forward, driving the first and second clamping drive linkages to rotate in the forward direction, causing the left and right tail fins to open relative to each other; when the object to be clamped is located between the left and right tail fins, the clamping drive servo rotates in reverse, driving the first and second clamping drive linkages to rotate in the opposite direction, causing the left and right tail fins to close relative to each other, using the enveloping clamping space between the left and right tail fins to enclose the target object, thus achieving the clamping of the target object; During the release process, the gripping drive servo rotates forward, driving the first and second gripping drive linkages to rotate in the forward direction, causing the left and right tail fins to open relative to each other and release the target. Subsequently, the gripping drive servo rotates in reverse, driving the first and second gripping drive linkages to rotate in the opposite direction, causing the left and right tail fins to close completely.

3. The biomimetic robotic fish with tail fin deformation and gripping compatible with swimming as described in claim 1, characterized in that, After the left and right tail fins cover the target, the gripping drive servo uses holding torque to maintain the position of the left and right tail fins, thereby stably gripping the target.

4. The biomimetic robotic fish with tail fin deformation and gripping compatible with swimming as described in claim 1, characterized in that, The multi-joint tail swing mechanism includes multiple joint housings and multiple tail swing drive systems connected in sequence. The joint housings are fitted onto the tail swing drive systems, and each joint housing corresponds to one tail swing drive system. The tail swing drive system drives the corresponding joint housing to swing left and right.

5. The biomimetic robotic fish with tail fin deformation and gripping compatible with swimming as described in claim 4, characterized in that, The tail-swing drive system includes a tail-swing drive servo and a tail-swing drive rocker arm; The tail-swing drive rocker arm is connected to the tail-swing drive servo. The tail-swing drive rocker arm swings left and right under the drive of the tail-swing drive servo, causing the corresponding joint housing to swing. The first tail-swing drive servo is fixed inside the front pitch mechanism. The rear end of the last tail-swing drive rocker arm is connected to the clamping drive servo, and the clamping drive servo is fixed inside the last joint housing.

6. The biomimetic robotic fish with tail fin deformation and gripping compatible with swimming as described in claim 1, characterized in that, The electronic components include a main control module, a power supply module, and a sensing module; the power supply module is used to supply power to the bionic robotic fish; the sensing module is used to collect the posture information of the bionic robotic fish and transmit it to the main control module; the main control module is responsible for the coordination and management between the modules, processing the posture data and issuing control signals.

7. An underwater gripping and release method for a biomimetic robotic fish compatible with tail fin deformation gripping and swimming, based on any one of claims 1-6, characterized in that, Includes the following steps: S1. The multi-joint tail-swinging mechanism swings left and right, causing the left and right tail fins to swing left and right, achieving propulsion and turning, so that the bionic robotic fish can approach the target and hover to one side of the target. S2. The clamping drive servo rotates forward and drives the left and right tail fins to open relative to each other through the linkage mechanism so as to cover the target. S3. The front pitch adjustment mechanism adjusts the pitch angle of the rear structure of the bionic robotic fish relative to the front structure, so that the target object can accurately enter the enveloping clamping space between the left and right tail fins. S4. The gripping drive servo reverses and drives the left and right tail fins to gradually close through the linkage mechanism until a stable gripping of the target is formed. At this time, the gripping drive servo maintains the relative position of the left and right tail fins through its own holding torque. Then the front pitch adjustment mechanism restores the pitch angle of the rear structure relative to the front structure to the initial state. S5. The multi-joint tail-wagging mechanism swings left and right, driving the bionic robotic fish to swim to the release position; S6. The gripping drive servo rotates forward, driving the left and right tail fins to open relative to each other and release the target; then the gripping drive servo rotates in reverse, driving the left and right tail fins to close completely, completing one gripping task.

Images