Six-axis linkage mechanism based on the analog fish spanwise deformation wing structure

Abstract

The application discloses a six-axis linkage mechanism-based flapping wing structure for simulating spanwise deformation of fishes, and relates to the technical field of bionic robots. A driving rod and a supporting rod are rotationally connected to a flexible framework. A driving part output end is connected to the driving rod, and the driving rods of two adjacent flapping wing units are fixedly connected. One end of a third linkage is hingedly connected to the supporting rod, and the other end of the third linkage is hingedly connected to one end of a fourth linkage. One end of a first linkage is hingedly connected to the driving rod, and the other end of the first linkage is hingedly connected to the middle section of the third linkage. One end of a second linkage is hingedly connected to the middle section of the third linkage, and the other end of the second linkage is hingedly connected to the middle section of the fourth linkage. The six-axis linkage mechanism-based flapping wing structure for simulating spanwise deformation of fishes has simple structure and high reliability, can accurately simulate the three-dimensional swimming posture of a mechanical fish in water, and can flexibly adjust the amplitude, frequency and phase of movement, so that the mechanical fish can quickly and greatly swim or slowly and sinuously swim.

Description

Technical Field

[0001] This invention relates to the field of biomimetic robotics, and more specifically, to a spanwise deformable flapping wing structure based on a six-axis linkage mechanism to simulate fish. Background Technology

[0002] With the increasing emphasis on marine development, new requirements are being placed on underwater operations. Mechanical fish are commonly used in underwater operations, but existing mechanical fish employ numerous complex components such as linkages, hinges, and rib supports to achieve spanwise deformation. This excessive number of components not only increases the difficulty and cost of manufacturing and assembly but also reduces the reliability of the mechanism. In the complex underwater environment, more connection points are prone to loosening, wear, and failure. Furthermore, the coupling between spanwise deformation and other degrees of freedom is poor; for example, while achieving spanwise deformation, it cannot effectively balance chordal deformation and flapping motion, resulting in insufficient overall motion flexibility and an inability to achieve efficient and flexible three-dimensional maneuvering like a fish. Summary of the Invention

[0003] To overcome the shortcomings of existing technologies, this invention proposes a spanwise deformable flapping wing structure based on a six-axis linkage mechanism to simulate fish. The structure is simple, highly reliable, and can accurately simulate the three-dimensional swimming posture of a mechanical fish in water. It can also flexibly adjust the amplitude, frequency, and phase of the movement, thus enabling both rapid, large-amplitude swimming and meandering swimming.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] This invention provides a spanwise deformable flapping fin structure based on a six-axis linkage mechanism to simulate fish, including a drive unit and a biomimetic pectoral fin composed of an array of two or more flapping fin units. Each flapping fin unit includes a flexible skeleton and movable parts symmetrically arranged on both sides of the flexible skeleton. The movable parts include an active rod, a support rod, a first link, a second link, a third link, and a fourth link. The active rod and the support rod are rotatably connected to the flexible skeleton. The output end of the drive unit is connected to the active rod, and the active rods of two adjacent flapping fin units are fixedly connected. One end of the third link is hinged to the support rod, and the other end of the third link is hinged to one end of the fourth link. One end of the first link is hinged to the active rod, and the other end of the first link is hinged to the middle section of the third link. One end of the second link is hinged to the middle section of the third link, and the other end of the second link is hinged to the middle section of the fourth link.

[0006] In a preferred embodiment of the present invention, the driving unit is a power motor.

[0007] In a preferred embodiment of the present invention, both the first connecting rod and the second connecting rod are straight rods.

[0008] In a preferred embodiment of the present invention, both the third link and the fourth link are right-angled rods.

[0009] In a preferred embodiment of the present invention, the active rod and the support rod are arranged in parallel, with the active rod located below the support rod.

[0010] The beneficial effects of this invention are as follows:

[0011] 1. By combining a six-axis linkage mechanism and a flexible skeleton to simulate muscle contraction, it can provide sufficient output force and power, and generate sufficient deformation, thereby restoring the real spanwise bending and swaying movements of fish. It can also simulate stretching, contraction, and bending movements well. Moreover, this rigid linkage mechanism can enable the robotic fish to obtain stable thrust. Compared with the traditional shape memory alloy drive method, it has the advantages of strong anti-turbulence capability, long fatigue life, and large shape recovery stress.

[0012] 2. The robotic fish uses a six-axis linkage mechanism in conjunction with a flexible skeleton as its basic structural unit. It can adapt to various underwater terrains, greatly improving its flexibility and enabling it to cope with complex underwater environments to a high degree. Furthermore, it establishes a special swimming mode based on biomimicry, without disturbing fish. While closely observing the behavior and physiological characteristics of fish, it can collect the marine big data information needed by humans.

[0013] 3. The flexible skeleton of this device is easier to disassemble and install without affecting the mechanical structure on the outside of the flexible skeleton. Even if the joints are damaged, the parts can be replaced and maintained more easily, effectively reducing the time cost of assembly and disassembly.

[0014] 4. The six-axis linkage mechanism can provide multiple independent degrees of freedom of motion, enabling the robotic fish to achieve highly flexible movement during spanwise deformation.

[0015] 5. The structural characteristics of the six-axis linkage mechanism endow it with high rigidity, and it can maintain a stable structural form when subjected to large external forces. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the spanwise deformable flapping wing structure based on a six-axis linkage mechanism to simulate fish, provided in a specific embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the flapping wing unit;

[0018] Figure 3 This is a partial structural diagram of the activity section.

[0019] In the picture:

[0020] 1. Drive unit; 2. Flapping wing unit; 21. Flexible frame; 22. Movable part; 221. Active rod; 222. Support rod; 223. First link; 224. Second link; 225. Third link; 226. Fourth link. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] like Figure 1-3As shown, the embodiment provides a spanwise deformable flapping fin structure based on a six-axis linkage mechanism to simulate fish, including a drive unit 1 and a biomimetic pectoral fin composed of an array of two or more flapping fin units 2. The flapping fin unit 2 includes a flexible frame 21 and movable parts 22 symmetrically arranged on both sides of the flexible frame 21. The movable part 22 includes an active rod 221, a support rod 222, a first connecting rod 223, a second connecting rod 224, a third connecting rod 225, and a fourth connecting rod 226. The active rod 221 and the support rod 222 are rotatably connected to the flexible frame 21. The output end of the drive unit 1 is connected to the active rod 221, and the active rods 221 of two adjacent flapping wing units 2 are fixedly connected. One end of the third connecting rod 225 is hinged to the support rod 222, and the other end of the third connecting rod 225 is hinged to one end of the fourth connecting rod 226. One end of the first connecting rod 223 is hinged to the active rod 221, and the other end of the first connecting rod 223 is hinged to the middle section of the third connecting rod 225. One end of the second connecting rod 224 is hinged to the middle section of the third connecting rod 225, and the other end of the second connecting rod 224 is hinged to the middle section of the fourth connecting rod 226. In this embodiment, two or more flapping wing units 2 are arranged in an axial array along the power shaft of the drive unit 1, and two adjacent flapping wing units 2 are detachably connected. This allows the parameters of each flapping wing unit 2 (such as the length of the rod, the size of the flexible frame, etc.) to be modified according to the characteristics of the biomimetic object, thereby realizing the design of motion from local to overall. The drive unit 1 is used to drive the flapping wing unit 2 to swing. When the flapping wing units 2 on both sides of the flexible frame 21 swing at the same speed, a backward thrust is generated, causing the mechanical fish to swim forward. It can also achieve upward and downward bending and swinging movements to simulate muscle contraction movements. When the flapping wing units 2 on both sides of the flexible frame 21 swing at different speeds, the mechanical fish can achieve turning movements, which are close to the real movement state of fish. The flexible frame 21 is made of flexible material and is suitable for cartilaginous fish. The moving part 22 is a six-axis linkage mechanism. The drive unit 1 can drive the active rod 221 to rotate. The rotation of the active rod 221 drives the first link 223 to move, which in turn drives the six-axis linkage mechanism to swing. The structural characteristics of the six-axis linkage mechanism give it high rigidity and can maintain a stable structural shape when subjected to large external forces. The six-axis linkage mechanism also possesses multiple degrees of freedom of motion. Compared with simple single-axis or dual-axis mechanisms, it can more accurately simulate the three-dimensional swimming posture of fish in water, and the robotic fish can flexibly adjust the amplitude, frequency, and phase of its motion during movement. By controlling the motion parameters of each axis of the six-axis linkage mechanism, it can perform both rapid, large-amplitude swimming and meandering swimming. Therefore, this device can effectively mimic the longitudinal undulation and efficient propulsion movement of fish.Furthermore, when the mechanical fish swims in the water, during each spanwise undulation interval, the flapping wings maintain a certain position, thus utilizing the energy of the water flow to convert it into the kinetic energy of the mechanical fish, allowing it to glide. This increases the swimming distance and speed with the same amount of energy, thereby improving the system's energy efficiency. At the same time, using 3D printing technology to manufacture the aforementioned integrated structural components reduces assembly steps, thereby reducing the risk of failure due to too many parts. Moreover, without compromising the structural strength, the lightweight design helps reduce fluid resistance and increase movement speed.

[0023] Specifically, the drive unit 1 is a power motor. In this embodiment, two power motors are provided, and the power shaft of each power motor is connected to the drive rod 221 of one of the flapping wing units 2.

[0024] Specifically, both the first link 223 and the second link 224 are straight rods. In this embodiment, both ends of the first link 223 and the second link 224 are provided with through holes for hinge connection.

[0025] Specifically, both the third link 225 and the fourth link 226 are right-angled rods. In this embodiment, the three ends of the third link 225 are provided with through holes for hinged connection, and two ends of the fourth link 226 are provided with through holes for hinged connection.

[0026] Specifically, the active rod 221 and the support rod 222 are arranged in parallel, with the active rod 221 located below the support rod 222.

[0027] This invention has been described through preferred embodiments. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. This invention is not limited to the specific embodiments disclosed herein; other embodiments falling within the scope of the claims are also within the protection scope of this invention.

Claims

1. A spanwise deformable flapping wing structure based on a six-axis linkage mechanism to simulate the flapping wing of a fish, characterized in that: The device includes a drive unit (1) and a biomimetic pectoral fin composed of an array of two or more flapping wing units (2). Each flapping wing unit (2) includes a flexible frame (21) and movable parts (22) symmetrically arranged on both sides of the flexible frame (21). The movable parts (22) include an active rod (221), a support rod (222), a first connecting rod (223), a second connecting rod (224), a third connecting rod (225), and a fourth connecting rod (226). The active rod (221) and the support rod (222) are rotatably connected to the flexible frame (21). The output end of the drive unit (1) is connected to the active rod (223). 21) The active rods (221) of two adjacent flapping wing units (2) are fixedly connected. One end of the third link (225) is hinged to the support rod (222), and the other end of the third link (225) is hinged to one end of the fourth link (226). One end of the first link (223) is hinged to the active rod (221), and the other end of the first link (223) is hinged to the middle section of the third link (225). One end of the second link (224) is hinged to the middle section of the third link (225), and the other end of the second link (224) is hinged to the middle section of the fourth link (226).

2. The spanwise deformable flapping wing structure for simulating fish based on a six-axis linkage mechanism according to claim 1, characterized in that: The drive unit (1) is a power motor.

3. The spanwise deformable flapping wing structure for simulating fish based on a six-axis linkage mechanism according to claim 1, characterized in that: Both the first link (223) and the second link (224) are straight rods.

4. The spanwise deformable flapping wing structure for simulating fish based on a six-axis linkage mechanism according to claim 1, characterized in that: Both the third link (225) and the fourth link (226) are right-angled rods.

5. The spanwise deformable flapping wing structure for simulating fish based on a six-axis linkage mechanism according to claim 1, characterized in that: The active rod (221) and the support rod (222) are arranged in parallel, and the active rod (221) is located below the support rod (222).

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