A fin-body fusion bionic pectoral fin mechanism driven by memory alloy

Abstract

The present invention discloses a fin-body fusion bionic pectoral fin mechanism driven by a memory alloy, characterized in that it includes a fish body, a pectoral fin skin, a pectoral fin base, a wire hole, a fin ray memory alloy actuator group, a fin ray group, a memory alloy spring group, and a fin root group; the fish body is a local part of the fish shell, and is only used to illustrate the connection method between the pectoral fin and the fish body; the pectoral fin base is installed in the groove of the fish body, the fin roots are all installed in the axial holes of the pectoral fin base, the fin rays are all bonded to their respective fin roots, the memory alloy actuator is bonded to the corresponding fin ray surface, the memory alloy spring is connected to the corresponding fin root, and the pectoral fin skin is connected to the pectoral fin base. The present invention drives the fin ray to bend through the memory alloy actuator and the memory alloy spring to control the rigid-flexible coupling fin surface to realize the movement of adduction, abduction, curling, bending and multi-free fluctuation; the pectoral fin base is connected to the groove on the surface of the fish body, eliminating the sheathing between the pectoral fin root and the fish body, having the characteristics of fin-body fusion, and increasing the pectoral fin thrust.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater robots and relates to a fin-body-fused bionic pectoral fin mechanism driven by a memory alloy. Background Art

[0002] Bionic robotic fish is a new type of underwater robot with high maneuverability, high concealment and low noise. It is widely used in underwater resource exploration, underwater equipment inspection, underwater biological observation and underwater archeology. The bionic pectoral fin, as the propulsion mechanism and motion posture adjustment mechanism of the robotic fish, can significantly improve the swimming performance and stability of the robotic fish. Therefore, the researchers hope to imitate the pectoral fin bone structure of fish to design a rigid-flexible coupling pectoral fin drive mechanism that takes into account both swimming efficiency and stability.

[0003] Existing research shows that the pectoral fin mechanism must not only meet the requirements of rigid-flexible coupling fin surface to achieve inward, outward, curling, bending and multi-freedom fluctuation movement postures, but also need to be designed to eliminate the gap between the pectoral fin root and the fish body to achieve the fin-body fusion function. However, the existing pectoral fin mechanism is a three-freedom drive mechanism that drives the rigid fin surface to complete wing flapping or wing shaking movement, or only drives the rigid-flexible coupling fin surface movement, ignoring the pectoral fin inward, outward, curling, bending and multi-freedom fluctuation movement postures; and the internal three-degree-of-freedom drive mechanism drives the fin surface movement with the output shaft, and there is a large gap between the fish body surface and the pectoral fin.

[0004] The present invention drives the rigid-flexible coupling fin surface to realize the movements of adduction, abduction, curling, bending and multiple free fluctuations through the bending of fin rays, and can also eliminate the seam between the pectoral fin root and the fish body to realize the functional characteristics of fin-body fusion, thereby increasing the thrust of the rigid-flexible coupling pectoral fin. Summary of the invention

[0005] In view of the problems in the technical background, the present invention provides a fin-body fusion bionic pectoral fin mechanism driven by a memory alloy, which controls the fluctuation of the pectoral fin surface through a memory alloy actuator to achieve multi-degree-of-freedom movement of the fin surface.

[0006] The present invention provides a fin-body fusion bionic pectoral fin mechanism driven by a memory alloy, which is installed in an external groove of a bionic robotic fish body, thereby greatly reducing the installation gap between the fish body and the pectoral fin. The invention is characterized in that it includes a fish body, a pectoral fin skin, a pectoral fin base, a first wire hole, a second wire hole, a first fin ray memory alloy actuator, a second fin ray memory alloy actuator, a third fin ray memory alloy actuator, a fourth fin ray memory alloy actuator, a fifth fin ray memory alloy actuator, a sixth fin ray memory alloy actuator, a seventh fin ray memory alloy actuator, an eighth fin ray memory alloy actuator, a first fin ray, a second fin ray, a third fin ray, a fourth fin ray, a first memory alloy spring, a second memory alloy spring, a third memory alloy spring, a first fin root, a second fin root, a third fin root, and a fourth fin root; the fish body is a local part of the fish body, and is only used to illustrate the connection method between the pectoral fin and the fish body; the pectoral fin base is installed to the groove of the fish body, and the fin roots are all installed to the axial hole of the pectoral fin base, and the movement of each fin ray is driven by the memory alloy actuator to realize the span-wise and chord-wise fluctuations of the pectoral fin surface in a rigid-flexible coupling manner.

[0007] As a further technical solution, the first fin root, the second fin root, the third fin root and the fourth fin root are all connected to the corresponding axial holes of the pectoral fin base, so that the fin rays have the freedom to rotate around the axis; the axial hole of the pectoral fin base is a blind hole, and the size of the opening limits the movement angle of the fin root. The movement angle range of the first fin root is -45 degrees to 60 degrees, the movement angle range of the second fin root is -60 degrees to 60 degrees, the movement angle range of the third fin root is -60 degrees to 60 degrees, and the movement angle range of the fourth fin root is -60 degrees to 60 degrees.

[0008] As a further technical solution, the first fin root is connected to the second fin root through a first memory alloy spring, the second fin root is connected to the third fin root through a second memory alloy spring, and the third fin root is connected to the fourth fin root through a third memory alloy spring; the first memory alloy spring, the second memory alloy spring and the third memory alloy spring are all made of memory alloy, and the memory alloy spring is driven to expand and contract by electric current, so that the fin root moves inward and outward.

[0009] As a further technical solution, the first fin ray, the second fin ray, the third fin ray and the fourth fin ray are respectively connected to the first fin root, the second fin root, the third fin root and the fourth fin root by bonding, and the materials are all elastic thermoplastic polyurethane rubber.

[0010] As a further technical solution, the first fin ray memory alloy actuator and the fifth fin ray memory alloy actuator are respectively fixed to the front and back sides of the first fin ray; the second fin ray memory alloy actuator and the sixth fin ray memory alloy actuator are respectively fixed to the front and back sides of the second fin ray; the third fin ray memory alloy actuator and the seventh fin ray memory alloy actuator are respectively fixed to the front and back sides of the third fin ray; the fourth fin ray memory alloy actuator and the eighth fin ray memory alloy actuator are respectively fixed to the front and back sides of the fourth fin ray.

[0011] As a further technical solution, the first fin ray memory alloy actuator, the second fin ray memory alloy actuator, the third fin ray memory alloy actuator, the fourth fin ray memory alloy actuator, the fifth fin ray memory alloy actuator, the sixth fin ray memory alloy actuator, the seventh fin ray memory alloy actuator and the eighth fin ray memory alloy actuator all use electric current to drive the memory alloy wire to expand and contract, so that the fins are bent and deformed.

[0012] As a further technical solution, the pectoral fin skin is connected to the pectoral fin base using interference fit, and the pectoral fin skin is covered to the first fin root, the second fin root, the third fin root, the fourth fin root and the first fin ray, the second fin ray, the third fin ray, and the fourth fin ray.

[0013] As a further technical solution, both the first wire through hole and the second wire through hole can drive the wires through the memory alloy and be sealed with soft glue.

[0014] As a further technical solution, a robotic fish is provided, comprising the above-mentioned memory alloy-driven fin-body fusion bionic pectoral fin mechanism.

[0015] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention.

[0016] The beneficial effects of the present invention are:

[0017] The pectoral fin mechanism drives the fin ray bending through a memory alloy actuator and a memory alloy spring to control the rigid-flexible coupled fin surface to achieve movements such as adduction, abduction, curling, bending and multi-free fluctuation.

[0018] The pectoral fin base is directly connected to the surface of the fish body, eliminating the gap between the pectoral fin root and the fish body, realizing the fin-body fusion function and increasing the thrust of the rigid-flexible coupled pectoral fin. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the three-dimensional structure of a memory alloy-driven fin-body-fused bionic pectoral fin mechanism with a skin according to an embodiment of the present invention.

[0020] Figure 2It is a schematic diagram of the three-dimensional structure of a memory alloy-driven fin-body-fused bionic pectoral fin mechanism without skin according to an embodiment of the present invention.

[0021] Figure 3 for Figure 1 A rear view of a memory alloy driven fin-body fusion bionic pectoral fin mechanism is shown.

[0022] Figure 4 for Figure 2 A bottom view of a memory alloy driven fin-body fusion bionic pectoral fin mechanism is shown.

[0023] Figure 5 for Figure 2 The illustrated diagram is a directional view of a memory alloy driven fin-body fusion bionic pectoral fin mechanism in directions A and B.

[0024] Figure 6 for Figure 2 A cross-sectional view of a memory alloy-driven fin-body-fused bionic pectoral fin mechanism on the CC section line is shown.

[0025] Figure 7 for Figure 2 A partial view of the fin root, fin ray and memory alloy actuator in a memory alloy-driven fin-body fusion bionic pectoral fin mechanism is shown.

[0026] Figure markings: fish body 1, pectoral fin skin 2, pectoral fin base 3, first fin ray memory alloy actuator 401, second fin ray memory alloy actuator 402, third fin ray memory alloy actuator 403, fourth fin ray memory alloy actuator 404, fifth fin ray memory alloy actuator 405, sixth fin ray memory alloy actuator 406, seventh fin ray memory alloy actuator 407, eighth fin ray memory alloy actuator 408, first fin ray 501, second fin ray 502, third fin ray 503, fourth fin ray 504, first memory alloy spring 601, second memory alloy spring 602, third memory alloy spring 603, first fin root 701, second fin root 702, third fin root 703, fourth fin root 704, first wire passing hole 801, second wire passing hole 802. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be understood that the present invention uses the terms "first", "second", etc. to describe various information, but these information should not be limited to these terms, and these terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0029] Please refer to the attached Figure 1-Figure 7 The present invention is a memory alloy-driven fin-body-fused bionic pectoral fin mechanism, which is installed in the external groove of the bionic robot fish body, greatly reducing the installation gap between the fish body and the pectoral fin, and controlling the inward and outward movement of the pectoral fin rays and the fluctuation of the fin surface through the memory alloy spring and the memory alloy actuator, so as to realize the multi-degree-of-freedom movement of the pectoral fin. It is characterized in that: the fish body 1 is a local part of the fish shell, which is only used to illustrate the connection method between the pectoral fin and the fish body; the pectoral fin base 3 is installed to the rectangular groove of the fish body 1 by bolts and nuts, reducing the installation gap between the pectoral fin and the fish body, so that the fluctuation of the pectoral fin generates greater propulsion force, and improves the swimming efficiency of the robot fish.

[0030] The first fin root 701, the second fin root 702, the third fin root 703 and the fourth fin root 704 are all connected to the corresponding axial holes of the pectoral fin base 3, so that the fin roots have the freedom to rotate around the axis; the axial hole of the pectoral fin base 3 is a blind hole, and the size of the opening limits the movement angle of the fin root. The movement angle range of the first fin root 701 is -45 degrees to 60 degrees, the movement angle range of the second fin root 702 is -60 degrees to 60 degrees, the movement angle range of the third fin root 703 is -60 degrees to 60 degrees, and the movement angle range of the fourth fin root 704 is -60 degrees to 60 degrees.

[0031] The first fin root 701 is connected to the second fin root 702 through the first memory alloy spring 601, the second fin root 702 is connected to the third fin root 703 through the second memory alloy spring 602, and the third fin root 703 is connected to the fourth fin root 704 through the third memory alloy spring 603; the first memory alloy spring 601, the second memory alloy spring 602 and the third memory alloy spring 603 are all made of memory alloy, and the memory alloy spring is driven to expand and contract by electric current, so that the fin root rotates around the axial hole of the pectoral fin base 3, thereby realizing the inward and outward movement of the pectoral fin.

[0032] The first fin 501, the second fin 502, the third fin 503 and the fourth fin 504 are respectively connected to the first fin root 701, the second fin root 702, the third fin root 703 and the fourth fin root 704 by bonding. The materials are all elastic thermoplastic polyurethane rubber, which can bend with the memory alloy and restore the original length after power failure.

[0033] The first fin ray memory alloy actuator 401 and the fifth fin ray memory alloy actuator 405 are respectively fixed to the front and back sides of the first fin 501 by bonding; the second fin ray memory alloy actuator 402 and the sixth fin ray memory alloy actuator 406 are respectively fixed to the front and back sides of the second fin 502 by bonding; the third fin ray memory alloy actuator 403 and the seventh fin ray memory alloy actuator 407 are respectively fixed to the front and back sides of the third fin 503 by bonding; the fourth fin ray memory alloy actuator 404 and the eighth fin ray memory alloy actuator 408 are respectively fixed to the front and back sides of the fourth fin 504 by bonding.

[0034] The first fin ray memory alloy actuator 401, the second fin ray memory alloy actuator 402, the third fin ray memory alloy actuator 403, the fourth fin ray memory alloy actuator 404, the fifth fin ray memory alloy actuator 405, the sixth fin ray memory alloy actuator 406, the seventh fin ray memory alloy actuator 407 and the eighth fin ray memory alloy actuator 408 all drive the memory alloy wire in the memory alloy actuator to expand and contract by current, control the bending movement of each fin ray, simulate the spanwise fluctuation of the pectoral fin surface, and control the different curvature of the fin ray by inputting different current magnitudes into each memory alloy wire to simulate the chordwise fluctuation of the pectoral fin surface.

[0035] The pectoral fin skin 2 is connected to the pectoral fin base 3 using an interference fit, and the pectoral fin skin 2 is covered with the first fin root 701, the second fin root 702, the third fin root 703, the fourth fin root 704 and the first fin ray 501, the second fin ray 502, the third fin ray 503, and the fourth fin ray 504; the pectoral fin skin 2 is cast using silicone rubber material and has a certain elasticity, so that the fin roots and fin rays can tear the pectoral fin skin 2 to move.

[0036] The first wire-passing hole 801 and the second wire-passing hole 802 can both drive wires through memory alloy and be sealed with soft glue.

[0037] Through the above-mentioned mechanism and method, the present invention can complete the movement postures of the pectoral fin of the robot fish, such as inward, outward, curling, bending and multiple free fluctuations; because the pectoral fin bones of the fish are inside the fish body and the movement center is on the surface of the fish body, the pectoral fins slap the fluid between the fish body and obtain a large propulsion force; in order to eliminate the overlap between the pectoral fin and the fish body and realize the functional characteristics of fin-body fusion, the present invention designs a memory alloy driven bionic pectoral fin mechanism that is tightly integrated with the fish body.

[0038] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A memory alloy-driven fin-body-fused bionic pectoral fin mechanism, installed in the external groove of the bionic robotic fish body, greatly reduces the installation gap between the fish body and the pectoral fin, controls the pectoral fin surface fluctuation through the memory alloy actuator, and realizes the multi-degree-of-freedom movement of the fin surface; it is characterized by: It includes a fish body, a pectoral fin skin, a pectoral fin base, a first wire hole, a second wire hole, a first fin ray memory alloy actuator, a second fin ray memory alloy actuator, a third fin ray memory alloy actuator, a fourth fin ray memory alloy actuator, a fifth fin ray memory alloy actuator, a sixth fin ray memory alloy actuator, a seventh fin ray memory alloy actuator, an eighth fin ray memory alloy actuator, a first fin ray, a second fin ray, a third fin ray, a fourth fin ray, a first memory alloy spring, a second memory alloy spring, a third memory alloy spring, a first fin root, a second fin root, a third fin root, and a fourth fin root; the pectoral fin base is installed to the groove of the fish body, and the fin roots are all installed to the axial hole of the pectoral fin base, and each fin ray is driven to move by the memory alloy actuator to realize the span-wise and chord-wise fluctuations of the pectoral fin surface with rigid-flexible coupling; The first fin root is connected to the second fin root through a first memory alloy spring, the second fin root is connected to the third fin root through a second memory alloy spring, and the third fin root is connected to the fourth fin root through a third memory alloy spring; the first memory alloy spring, the second memory alloy spring and the third memory alloy spring are all made of memory alloy, and the memory alloy spring is driven to expand and contract by electric current, so that the fin root moves inward and outward; The first fin ray memory alloy actuator and the fifth fin ray memory alloy actuator are respectively fixed to the front and back sides of the first fin ray; the second fin ray memory alloy actuator and the sixth fin ray memory alloy actuator are respectively fixed to the front and back sides of the second fin ray; the third fin ray memory alloy actuator and the seventh fin ray memory alloy actuator are respectively fixed to the front and back sides of the third fin ray; the fourth fin ray memory alloy actuator and the eighth fin ray memory alloy actuator are respectively fixed to the front and back sides of the fourth fin ray.

2. The memory alloy driven fin body fusion bionic pectoral fin mechanism according to claim 1, characterized in that: The first fin root, the second fin root, the third fin root and the fourth fin root are all connected to the corresponding axial holes of the pectoral fin base, so that the fin rays have the freedom to rotate around the axis; the axial hole of the pectoral fin base is a blind hole, and the size of the opening limits the movement angle of the fin root. The movement angle range of the first fin root is -45 degrees to 60 degrees, the movement angle range of the second fin root is -60 degrees to 60 degrees, the movement angle range of the third fin root is -60 degrees to 60 degrees, and the movement angle range of the fourth fin root is -60 degrees to 60 degrees.

3. The memory alloy driven fin-body fusion bionic pectoral fin mechanism according to claim 1, characterized in that: The first fin ray, the second fin ray, the third fin ray and the fourth fin ray are respectively connected to the first fin root, the second fin root, the third fin root and the fourth fin root by bonding, and the materials are all elastic thermoplastic polyurethane rubber.

4. The memory alloy driven fin-body fusion bionic pectoral fin mechanism according to claim 1, characterized in that: The first fin ray memory alloy actuator, the second fin ray memory alloy actuator, the third fin ray memory alloy actuator, the fourth fin ray memory alloy actuator, the fifth fin ray memory alloy actuator, the sixth fin ray memory alloy actuator, the seventh fin ray memory alloy actuator and the eighth fin ray memory alloy actuator all use electric current to drive the memory alloy wire to expand and contract, so that the fins are bent and deformed.

5. The memory alloy driven fin-body fusion bionic pectoral fin mechanism according to claim 1, characterized in that: The pectoral fin skin is connected to the pectoral fin base by interference fit, and the pectoral fin skin is covered to the first fin root, the second fin root, the third fin root, the fourth fin root and the first fin ray, the second fin ray, the third fin ray, and the fourth fin ray.

6. The memory alloy driven fin-body fusion bionic pectoral fin mechanism according to claim 1, characterized in that: The first wire-passing hole and the second wire-passing hole can both drive wires through the memory alloy and are sealed by using soft glue.

7. A bionic robotic fish, characterized in that: A fin-body fusion bionic pectoral fin mechanism driven by a memory alloy as described in any one of claims 1 to 6.

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