A multi-point excited variable stiffness tensile bionic robotic fish structure

Abstract

This invention relates to a multi-point excited variable stiffness tensioned biomimetic robotic fish structure, comprising a head module, a flexible body module, and a fin module. The flexible body module includes a tensioned integral structure, a flexible fish skin, and active and passive ropes. The tensioned integral structure includes multiple joint components, adjacent of which are connected by springs. The fin module includes left and right pectoral fins and a flexible caudal fin, with the caudal fin base connected to the rearmost joint component. The head module includes a head base, a drive mechanism, a first guide rail slider mechanism, and a head shell. The head base is connected to the foremost joint component. The drive mechanism includes two pairs of servos. The left and right sides of the upper and lower servo blades are connected to the middle joint component and the caudal fin base via the first and second active ropes, respectively. The left and right servo blades are connected to the left and right pectoral fins, respectively. One end of the upper and lower passive ropes is connected to the first guide rail slider mechanism, and the other end is connected to the caudal fin base. This biomimetic robotic fish structure improves the flexibility and realism of the biomimetic robotic fish.

Description

Technical Field

[0001] This invention relates to the field of biomimetic robot technology, specifically to a multi-point excited variable stiffness tensioned biomimetic robotic fish structure. Background Technology

[0002] As the development and utilization of land resources become increasingly mature and sophisticated, the importance of effectively developing and utilizing marine resources is becoming increasingly prominent, leading to the emergence of various autonomous underwater vehicles (AUVs). With the development of fluid biomimetic and underwater robotics technologies, the field of robotics has begun to see the development of underwater robots inspired by fish. Robotic fish, as a new type of underwater robot, achieve their tasks by simulating the movement of fish in water. Unlike traditional underwater robots that use propeller-driven propulsion, biomimetic robotic fish are characterized by high flexibility, low noise, and high propulsion efficiency. Currently, most robotic fish employ a multi-joint rigid series structure, with each joint driven by a motor. However, this approach suffers from load imbalance, and the structural and control complexity increases with the number of joints. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-point excited variable stiffness tensioned bionic robotic fish structure, which improves the flexibility and realism of the bionic robotic fish.

[0004] To achieve the above objectives, the technical solution adopted by this invention is: a multi-point excited variable stiffness tensioned bionic robotic fish structure, comprising a fish head module, a flexible body module, and a fish fin module. The flexible body module includes a tensioned overall structure, a flexible fish skin, and multiple active and passive ropes. The tensioned overall structure includes multiple joint components and multiple sets of springs arranged sequentially front to back, with adjacent joint components connected by a set of springs. The fish fin module includes left and right pectoral fins and a flexible caudal fin. The flexible caudal fin includes a caudal fin base frame and a flexible part with a caudal fin shape disposed outside it. The caudal fin base frame is connected forward to the rearmost joint component via a set of springs. The fish head module includes a fish head base frame, a drive mechanism, a first guide rail slider mechanism, and a fish head shell. The fish head base frame is connected backward to the frontmost joint component via a set of springs. The first guide rail slider mechanism... The drive mechanism is mounted on the rear side of the fish head base. It includes two pairs of servos mounted on the fish head base. The left and right sides of the upper servo blades are connected to the first active ropes. The two first active ropes pass through the fish head base and several joint components and are connected to the left and right sides of a joint component located in the middle. The left and right sides of the lower servo blades are connected to the second active ropes. The two second active ropes pass through the fish head base and all joint components and are connected to the tail fin base. This allows the robot fish to swing left and right through a rope-driven underactuated method. The left and right servo blades are fixedly connected to the left and right pectoral fins, respectively. This allows the robot fish to rise and fall by changing the angle of attack of the pectoral fins. The upper and lower sliders on the first guide rail slider mechanism are connected to the upper and lower passive ropes, respectively. The upper and lower passive ropes pass through all joint components and are connected to the tail fin base. The fish head shell is mounted on the outside of the fish head base.

[0005] Furthermore, the joint component includes an elliptical ring, with forward-facing front connecting rods fixed to its upper and lower sides, and backward-facing rear connecting rods fixed to its left and right sides. The elliptical ring has through holes on its upper, lower, left, and right sides for the passage of active and passive ropes, respectively. Between adjacent joint components, the front ends of the two front connecting rods of the rear joint component and the rear ends of the two rear connecting rods of the front joint component are on the same plane and connected end-to-end by four first springs. The front ends of the two front connecting rods of the rear joint component are also connected to the front ends of the two front connecting rods of the front joint component by two second springs. The caudal fin base is fixed forward-facing on its upper and lower sides. The tail fin base has two inwardly oriented front connecting rods. The front ends of the two front connecting rods of the tail fin base and the rear ends of the two rear connecting rods of the rearmost joint component are located on the same plane and connected end-to-end by four first springs. The front ends of the two front connecting rods of the tail fin base are also connected to the front ends of the two front connecting rods of the rearmost joint component by two second springs. The fish head base has two inwardly oriented rear connecting rods fixed to the left and right sides respectively. The front ends of the two front connecting rods of the foremost joint component and the rear ends of the two rear connecting rods of the fish head base are located on the same plane and connected end-to-end by four first springs. The front ends of the two front connecting rods of the foremost joint component are also connected to the fish head base or the first guide rail slider mechanism on it by two third springs.

[0006] Furthermore, the tensioned integral structure includes four joint components, and the size of the elliptical ring of the four joint components decreases sequentially from front to back.

[0007] Furthermore, two first active ropes are symmetrically arranged on the left and right. The front ends of the two first active ropes are fixedly connected to the left and right sides of the upper servo blades through the fourth spring, respectively. The rear ends of the two first active ropes pass through the fish head base and the first joint component and are fixedly connected to the left and right sides of the second joint component, respectively. This allows the driving force of the upper servo to be transmitted to the body of the robotic fish through the first active ropes. The oscillation of the upper servo blades causes the second joint component to oscillate back and forth through the first active ropes, thereby realizing the biomimetic simulation of the oscillation of the front half of the robotic fish. Two second active ropes are symmetrically arranged on the left and right. The front ends of the two first active ropes are fixedly connected to the left and right sides of the lower servo blades through the fifth spring, respectively. The rear ends of the two second active ropes pass through the fish head base and all joint components and are fixedly connected to the left and right sides of the tail fin base, respectively. This allows the driving force of the lower servo to be transmitted to the tail fin of the robotic fish through the second active ropes. The oscillation of the lower servo blades causes the flexible tail fin to oscillate back and forth through the second active ropes, thereby realizing the biomimetic simulation of the oscillation of the tail fin of the robotic fish.

[0008] Furthermore, the first guide rail slider mechanism is vertically installed on the rear side of the fish head base. The upper and lower parts of the first guide rail slider mechanism are each provided with a guide rail. The upper and lower guide rails are respectively provided with upper and lower sliders that can slide up and down and lock in position. The upper and lower sliders are respectively connected to upper and lower passive ropes, so as to change the rigidity of the machine fish by changing the displacement distance of the sliders and adjusting the pretension of the upper and lower passive ropes.

[0009] Furthermore, a second guide rail slider mechanism is provided on the front side of the tail fin base. The two second active ropes pass through the fish head base and all joint components respectively and are connected to the slider on the second guide rail slider mechanism so as to adjust the tension of the second active ropes by changing the displacement distance of the slider.

[0010] Furthermore, the fish head shell is a rigid structure, consisting of a rigid left fish head shell and a rigid right fish head shell connected together.

[0011] Furthermore, the flexible fish skin is silicone fish skin, which covers the outside of the tensioned overall structure, with its front end connected to the fish head shell, its middle part connected to each joint component, and its rear end connected to the flexible tail fin.

[0012] Compared with existing technologies, the present invention has the following advantages: The present invention provides a multi-point excited variable stiffness tensioned bionic robotic fish structure. The present invention has carried out an innovative design of a flexible torso module, and uses a combination of servo motors and rope drive to control the movement and propulsion of the robotic fish. The underactuated rope and multi-point excited drive method can well fit the body wave of real fish, thereby greatly improving the flexibility and simulation degree of the bionic robotic fish. The bionic robotic fish structure is novel, highly simulated, highly controllable, and highly efficient in propulsion, and has strong practicality and broad application prospects. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall external structure of an embodiment of the present invention;

[0014] Figure 2 This is a top view of the overall internal structure of an embodiment of the present invention;

[0015] Figure 3 This is a side view of the overall internal structure of an embodiment of the present invention;

[0016] Figure 4 This is a schematic diagram of the internal structure of the fish head module in an embodiment of the present invention;

[0017] Figure 5 This is a schematic diagram of the tensioned integral structure in an embodiment of the present invention;

[0018] Figure 6 This is a schematic diagram of the connection structure of adjacent joint components in an embodiment of the present invention.

[0019] In the diagram: 1. Upper servo; 2. Lower servo; 3. Left servo; 4. Right servo; 5. Fish head base frame; 6. First tension joint component; 7. Second tension joint component; 8. Third tension joint component; 9. Fourth tension joint component; 10. Tail fin base frame; 11. Rigid fish head left shell; 12. Rigid fish head right shell; 13. Silicone fish skin; 14. Flexible part with tail fin shape; 15. Bolt; 16. Blade; 17. First spring; 18. Second spring; 19. Third spring; 20. Fourth spring; 21. Fifth spring; 22. First guide rail slider mechanism; 23. Second guide rail slider mechanism; 24. First active rope; 25. Second active rope; 26. Upper passive rope; 27. Lower passive rope; 28. Left pectoral fin; 29. ​​Right pectoral fin; 30. Elliptical ring; 31. Front connecting rod; 32. Rear connecting rod. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] It should be noted that the following detailed descriptions are exemplary 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.

[0022] 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.

[0023] like Figure 1-6As shown, this embodiment provides a multi-point excited variable stiffness tensioned bionic robotic fish structure, including a fish head module, a flexible body module, and a fin module. The flexible body module includes a tensioned overall structure, a flexible fish skin 13, and multiple active and passive ropes. The multiple active and passive ropes are used to simulate the function of tendons. The tensioned overall structure includes multiple joint components and multiple sets of springs arranged sequentially front to back, with adjacent joint components connected by a set of springs. The fin module includes a left pectoral fin 28, a right pectoral fin 29, and a flexible tail fin. The flexible tail fin is used to provide the driving force for the robotic fish to move forward. The flexible tail fin includes a tail fin base 10 and a flexible part 14 with a tail fin shape disposed outside it. The tail fin base 10 is connected forward to the joint component at the rear end by a set of springs. The fish head module includes a fish head base frame 5, a drive mechanism, a first guide rail slider mechanism 22, and a fish head shell. The fish head base frame 5 is connected to the foremost joint component via a set of springs. The first guide rail slider mechanism 22 is installed on the rear side of the fish head base frame 5. The drive mechanism includes two pairs of servos respectively installed on the fish head base frame 5: an upper servo 1 and a lower servo 2, and a left servo 3 and a right servo 4. The upper servo 1, lower servo 2, left servo 3, and right servo 4 are respectively fixed to the four directions of the fish head base frame 5 by bolts. The left and right sides of the upper servo blades are respectively connected to the first drive ropes 24. The two first drive ropes 24 pass through the fish head base frame 5 and several joint components and are connected to a centrally located... The left and right sides of the joint components are connected, and the left and right sides of the lower servo blades are respectively connected to the second active ropes 25. The two second active ropes 25 pass through the fish head base 5 and all joint components and are connected to the tail fin base 10 to control the left and right swing of the robot fish through a rope-driven underactuated method. The left and right servo blades 16 are fixedly connected to the left pectoral fin 28 and the right pectoral fin 29 respectively, so as to change the angle of attack of the pectoral fins through the swing of the servo and thus control the upward and downward movement of the robot fish. The upper and lower sliders on the first guide rail slider mechanism 22 are respectively connected to the upper passive rope 26 and the lower passive rope 27. The upper passive rope 26 and the lower passive rope 27 pass through all joint components and are connected to the tail fin base 10. The fish head shell is installed on the outside of the fish head base 5.

[0024] Specifically, the joint component includes an elliptical ring 30, with forward-facing front connecting rods 31 fixedly connected to the upper and lower sides of the elliptical ring 30, and backward-facing rear connecting rods 32 fixedly connected to the left and right sides of the elliptical ring 30. The elliptical ring 30 has through holes on its upper, lower, left, and right sides for the passage of active and passive ropes, respectively. Between adjacent joint components, the front ends of the two front connecting rods of the rear joint component and the rear ends of the two rear connecting rods of the front joint component are on the same plane and connected end-to-end by four first springs 17. The front ends of the two front connecting rods of the rear joint component are also connected to the front ends of the two front connecting rods of the front joint component by two second springs 18. The caudal fin base frame 10 has forward-facing front connecting rods on its upper and lower sides. The two front connecting rods of the tail fin base 10 are fixedly connected to each other at an inward angle. The front ends of the two front connecting rods of the tail fin base 10 and the rear ends of the two rear connecting rods of the rearmost joint member are located on the same plane and connected end to end by four first springs. The front ends of the two front connecting rods of the tail fin base 10 are also connected to the front ends of the two front connecting rods of the rearmost joint member through two second springs. The fish head base 5 is fixedly connected to the rear connecting rods at an inward angle on the left and right sides respectively. The front ends of the two front connecting rods of the foremost joint member and the rear ends of the two rear connecting rods of the fish head base 5 are located on the same plane and connected end to end by four first springs. The front ends of the two front connecting rods of the foremost joint member are also connected to the fish head base 5 or the first guide rail slider mechanism on it through two third springs 19.

[0025] In this embodiment, the tensioned integral structure includes four joint components: a first tensioning joint component 6, a second tensioning joint component 7, a third tensioning joint component 8, and a fourth tensioning joint component 9. The elliptical rings of the four joint components decrease in size from front to back, similar to the shape and size of a real fish. By connecting these joint components, the spine and trunk structure of the robotic fish are formed. In different embodiments of the present invention, the tensioned integral structure may include different numbers of joint components to simulate different fish species.

[0026] Two first active ropes 24 are symmetrically arranged on the left and right. The front ends of the two first active ropes 24 are fixedly connected to the left and right sides of the upper servo blades through the fourth spring 20, respectively. The rear ends of the two first active ropes 24 pass through the fish head base 5 and the first joint component and are fixedly connected to the left and right sides of the second joint component, respectively, so as to transmit the driving force of the upper servo to the body of the robotic fish through the first active ropes. The swing of the upper servo blades drives the second joint component to swing back and forth through the first active ropes, thereby realizing the biomimetic simulation of the swing of the front half of the robotic fish. Two second active ropes 25 are symmetrically arranged on the left and right sides. The front ends of the two first active ropes 25 are fixedly connected to the left and right sides of the lower servo blades via the fifth spring 21, respectively. The rear ends of the two second active ropes 25 pass through the fish head base 5 and all joint components and are fixedly connected to the left and right sides of the tail fin base 10, respectively. This allows the driving force of the lower servo to be transmitted to the tail fin of the robotic fish through the second active ropes. The oscillation of the lower servo blades causes the flexible tail fin to swing back and forth through the second active ropes, thereby realizing the biomimetic simulation of the tail fin oscillation of the robotic fish. The shape control of the tail fin is achieved by using the underactuated and multi-point excitation modes of the servo to pull the second active ropes. Through the combined action of the upper servo 1 and the lower servo 2, the biomimetic robotic fish can swim and move forward in the water.

[0027] In this embodiment, the first guide rail slider mechanism 22 is vertically installed on the rear side of the fish head base 5. The upper and lower parts of the first guide rail slider mechanism 22 are respectively provided with a guide rail. The upper and lower guide rails are respectively provided with upper and lower sliders that can slide up and down and lock in position. The upper and lower sliders are respectively connected to the upper passive rope 26 and the lower passive rope 27, so as to change the rigidity of the machine fish by changing the displacement distance of the sliders to adjust the pretension of the upper and lower passive ropes.

[0028] A second guide rail slider mechanism 23 is provided on the front side of the caudal fin base frame 10. The two second active ropes pass through the fish head base frame 5 and all joint components respectively and are connected to the slider on the second guide rail slider mechanism 23 so as to adjust the tension of the second active rope by changing the displacement distance of the slider.

[0029] In this embodiment, the fish head shell is a rigid structure, composed of a rigid left fish head shell 11 and a rigid right fish head shell 12 connected together. The flexible fish skin 13 is made of silicone fish skin, which covers the outside of the tensioned integral structure. Its front end is connected to the fish head shell, its middle part is connected to each joint component through bolts 15 set on the elliptical ring, and its rear end is connected to the tail fin base 10 of the flexible tail fin. In this embodiment, the flexible part 14 with the tail fin shape is cast into the tail fin base 10 using silicone.

[0030] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A multi-point excited variable stiffness tensioned biomimetic robotic fish structure, characterized in that, The system includes a fish head module, a flexible body module, and a fin module. The flexible body module comprises a tensioned integral structure, flexible fish skin, and multiple active and passive ropes. The tensioned integral structure includes multiple joint components and multiple sets of springs arranged sequentially front to back, with adjacent joint components connected by a set of springs. The fin module includes left and right pectoral fins and a flexible caudal fin. The flexible caudal fin includes a caudal fin base and a flexible part with a caudal fin shape. The caudal fin base is connected forward to the rearmost joint component via a set of springs. The fish head module includes a fish head base, a drive mechanism, a first guide rail slider mechanism, and a fish head shell. The fish head base is connected rearward to the frontmost joint component via a set of springs. The first guide rail slider mechanism is installed on the rear side of the fish head base. The drive mechanism includes... Two pairs of servos are mounted on the fish head base. The left and right sides of the upper servo blades are connected to the first active ropes. The two first active ropes pass through the fish head base and several joint components and are connected to the left and right sides of a joint component located in the middle. The left and right sides of the lower servo blades are connected to the second active ropes. The two second active ropes pass through the fish head base and all joint components and are connected to the tail fin base. This is to control the left and right swing of the robotic fish through a rope-driven underactuated method. The left and right servo blades are fixedly connected to the left and right pectoral fins, respectively. This is to control the rising and falling movement of the robotic fish by changing the angle of attack of the pectoral fins. The upper and lower sliders on the first guide rail slider mechanism are connected to the upper and lower passive ropes, respectively. The upper and lower passive ropes pass through all joint components and are connected to the tail fin base. The fish head shell is mounted on the outside of the fish head base. The joint component includes an elliptical ring. The upper and lower sides of the elliptical ring are respectively fixed forward with inwardly angled front connecting rods, and the left and right sides of the elliptical ring are respectively fixed backward with inwardly angled rear connecting rods. The elliptical ring has through holes on its upper, lower, left, and right sides to allow the active and passive ropes to pass through. Between adjacent joint components, the front ends of the two front connecting rods of the rear joint component and the rear ends of the two rear connecting rods of the front joint component are on the same plane and connected end-to-end by four first springs. The front ends of the two front connecting rods of the rear joint component are also connected to the front ends of the two front connecting rods of the front joint component by two second springs. The caudal fin base is respectively fixed forward with inwardly angled front connecting rods on its upper and lower sides. The two front connecting rods of the caudal fin base frame and the two rear connecting rods of the rearmost joint component are located on the same plane and connected end-to-end by four first springs. The two front connecting rods of the caudal fin base frame are also connected to the two front connecting rods of the rearmost joint component by two second springs. The left and right sides of the fish head base frame are respectively fixed with rear connecting rods that are obliquely inward. The two front connecting rods of the foremost joint component and the two rear connecting rods of the fish head base frame are located on the same plane and connected end-to-end by four first springs. The two front connecting rods of the foremost joint component are also connected to the fish head base frame or the first guide rail slider mechanism on it by two third springs.

2. The multi-point excited variable stiffness tensioned biomimetic robotic fish structure according to claim 1, characterized in that, The tensioned integral structure includes four joint components, and the size of the elliptical ring of the four joint components decreases sequentially from front to back.

3. The multi-point excited variable stiffness tensioned biomimetic robotic fish structure according to claim 1, characterized in that, Two first active ropes are symmetrically arranged on the left and right. The front ends of the two first active ropes are fixedly connected to the left and right sides of the upper servo blades through the fourth spring, respectively. The rear ends of the two first active ropes pass through the fish head base and the first joint component and are fixedly connected to the left and right sides of the second joint component, respectively. This allows the driving force of the upper servo to be transmitted to the body of the robotic fish through the first active ropes. The oscillation of the upper servo blades causes the second joint component to oscillate back and forth through the first active ropes, thus realizing the biomimetic simulation of the oscillation of the front half of the robotic fish. Two second active ropes are symmetrically arranged on the left and right. The front ends of the two second active ropes are fixedly connected to the left and right sides of the lower servo blades through the fifth spring, respectively. The rear ends of the two second active ropes pass through the fish head base and all joint components and are fixedly connected to the left and right sides of the tail fin base, respectively. This allows the driving force of the lower servo to be transmitted to the tail fin of the robotic fish through the second active ropes. The oscillation of the lower servo blades causes the flexible tail fin to oscillate back and forth through the second active ropes, thus realizing the biomimetic simulation of the oscillation of the tail fin of the robotic fish.

4. The multi-point excited variable stiffness tensioned biomimetic robotic fish structure according to claim 1, characterized in that, The first guide rail slider mechanism is vertically installed on the rear side of the fish head base. The upper and lower parts of the first guide rail slider mechanism are each provided with a guide rail. The upper and lower guide rails are respectively provided with upper and lower sliders that can slide up and down and lock in position. The upper and lower sliders are respectively connected to upper and lower passive ropes, so as to change the rigidity of the machine fish by changing the displacement distance of the sliders and adjusting the pretension of the upper and lower passive ropes.

5. The multi-point excited variable stiffness tensioned biomimetic robotic fish structure according to claim 1, characterized in that, A second guide rail slider mechanism is provided on the front side of the caudal fin base. The two second active ropes pass through the fish head base and all joint components respectively and are connected to the slider on the second guide rail slider mechanism so as to adjust the tension of the second active rope by changing the displacement distance of the slider.

6. The multi-point excited variable stiffness tensioned biomimetic robotic fish structure according to claim 1, characterized in that, The fish head shell is a rigid structure, consisting of a rigid left shell and a rigid right shell connected together.

7. The multi-point excited variable stiffness tensioned biomimetic robotic fish structure according to claim 1, characterized in that, The flexible fish skin is made of silicone. The flexible fish skin covers the outside of the tensioned overall structure, with its front end connected to the fish head shell, its middle part connected to each joint component, and its rear end connected to the flexible tail fin.

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