A flexible electrically powered bionic fish fin

Abstract

The present application provides a kind of flexible electric bionic fish fin, including fin part and motor drive part, by base installation to the main frame of bionic robot, fin part includes frame structure, fin part swing mechanism and fin part twist mechanism, fin part swing mechanism is driven by two flexible elastic belts, two elastic belts are synchronously driven by electric drive part installed in base, respectively along the fin direction with opposite speed and direction reciprocating motion, two described elastic belts are hinged with frame structure, fin part twist mechanism includes universal joint in fin part and long shaft connected by universal joint, long shaft connected by universal joint is driven by electric drive part installed in base, so that fin part is twisted around root part.The present application adopts multi-section universal joint coupling to drive fish fin twist, and variable cross-section elastic belt makes bionic fish fin device swing stiffness more closely real fish fin stiffness, twist and swing superposition effect makes movement more bionic, improves fin part swing power, improves the swimming speed of bionic fish.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of bionic fish structure design, and particularly relates to a flexible electric bionic fish fin with fin twisting function. BACKGROUND

[0002] The bionic fish underwater robot is one of the important research directions of underwater bionic robots. The fish fin is the swimming organ of the fish and plays an extremely important role in the swimming process of the fish. The fish fin is not only one of the driving parts of the fish swimming, but also plays a role in controlling the swimming posture and speed of the fish. Therefore, the bionic fish fin technology is one of the key technologies of the bionic fish underwater robot. Since the bionic fish fin plays multiple roles when the bionic fish underwater robot swims, the bionic effect of the bionic fish fin has a relatively high requirement. According to the research on the bionic fish fin in the field of underwater intelligent bionics, it is found that the current underwater bionic fish fin mostly adopts single-joint thick fin surface rotary motion or rudder pulling and curling fish fin. The former structure leads to low propulsion efficiency and poor bionic degree, and the latter ordinary rudder has small torque. The fin part of the existing bionic fish underwater robot mostly adopts motor-driven fin up-and-down swing, and the fin part is a rigid fin part. This method has rigid fish fin swing, poor driving capacity and insufficient bionic effect. SUMMARY

[0003] The technical problem solved by the present application is to provide a flexible electric bionic fish fin with fin twisting function, which uses a self-designed motor as a power source to make the torque much larger than that of an ordinary rudder and the fin part is driven by a variable cross-section elastic belt, thereby solving the problems of rigid fish fin swing, poor driving capacity and insufficient bionic effect.

[0004] The technical solution adopted by the present application is: a flexible electric bionic fish fin, comprising a fin part and a motor driving part, which is installed on the main body frame of a bionic robot through a base, the fin part comprises a frame structure, a fin swing mechanism and a fin twisting mechanism, the fin swing mechanism is driven by two elastic belts with toughness, the two elastic belts are synchronously driven by the electric driving part installed on the base, and reciprocate along the fin direction at opposite speeds and directions, the frame structure is hinged between the two elastic belts, the fin twisting mechanism comprises a universal joint in the fin part and a long shaft connected through the universal joint, the long shaft connected through the universal joint is driven by the electric driving part installed on the base to twist the fin part around the root part, the long shaft is a coaxial multi-section structure connected with multiple universal joints, along the fin direction, the rear end of the first section long shaft of the fin root part is connected with the electric driving part, and the front end is hinged with the first universal joint, the front end of the first universal joint is hinged with the second section long shaft, the front end of the second section long shaft is hinged with the second universal joint, and so on in sequence until the rear end of the universal joint at the front end is hinged with the long shaft, and the front end is connected with the fin tip, each long shaft is supported by a bearing assembly and fixed on the frame structure, and the universal joint is rotatable in the radial direction and extendable in the axial direction.

[0005] Preferably, the elastic band is a bendable band body with rigidity, the cross-sectional area of the elastic band in the length direction is variable, the cross-sectional area is maximum at the root of the fin, gradually decreases along the fin direction, and the cross-sectional area is minimum at the fin tip.

[0006] Preferably, the frame structure comprises a rigid fin type frame and a support frame and a fin tip, the rigid fin type frame is a plurality of rigid fin type frames arranged in parallel and at equal intervals along the fin direction, the head and tail ends of each rigid fin type frame are triangular frames with curvature for profiling the cross-sectional shape of the fish fin at the position, the tail side of the head end triangular frame is connected with the support frame, the support frame is connected with the tail end triangular frame through a cross beam, the rigid fin type frame is maximum at the root of the fin, gradually decreases along the fin direction, an independent support frame is arranged between the two adjacent rigid fin type frames, all the support frames are parallel and the geometric centers are on the same straight line, the support frame is a rectangular frame with hinges fixed on the upper and lower ends, and the fin tip is integrally connected with the fin tip through a flat plate.

[0007] Preferably, the electric drive part comprises a twist drive part and a swing drive part, the swing drive part comprises a first motor, a gear and a rack, the elastic band reciprocates through the first motor driving the gear and the rack, the twist drive part comprises a second motor, and the second motor is connected with one end of a long shaft to transmit the torsional force to the fin tip through the long shaft and a universal joint.

[0008] Preferably, the rigid fin type frames are elastically connected, the elastic connection is an elastic rope which sequentially passes through the rigid fin type frames along the fin direction and is elastically connected with the rigid fin type frames, cooperates with the fin swing mechanism to complete the coherent swing of the whole fin, avoids the tail end from showing a scattered posture when the head end is driven by the fin swing mechanism, and makes the tail end soft and better bionics.

[0009] Preferably, the elastic band is located on the upper and lower ends of the support frame, and the elastic band is connected with one side of the hinge of the support frame.

[0010] Preferably, the fin swing mechanism is located on the upper and lower surfaces of the support frame, and the fin twist mechanism passes through the hole in the support frame.

[0011] Preferably, the area surrounded by the outer contour of each rigid fin type frame is linearly related to the cross-sectional area of the elastic band at the connection position of the rigid fin type frame.

[0012] Preferably, the elastic connection has two, which are respectively located on the center line of the fin and the tail side of the fin.

[0013] Preferably, the outside of the fin is wrapped with a bionic skin.

[0014] The beneficial effects of the present application are:

[0015] 1、The present application adopts multi-section universal joint coupler to drive the fish fin to twist, and the variable cross-section elastic belt makes the bionic fish fin device swing stiffness more in line with the real fish fin stiffness, and the twisting and swinging superposition effect makes the movement more bionic.

[0016] 2、The swing driving part of the present application utilizes gear and rack mechanism to drive two elastic belts to synchronously reciprocate in two directions, the gear and rack transmission mode transmits large power, improves the fin swing power and the swimming speed of the bionic fish, the gear and rack transmission mode has accurate transmission ratio, long service life and improves the reliability of the bionic fish fin driving device.

[0017] 3、The twisting driving and swinging driving are respectively controlled by the corresponding motors, can jointly act or singly act, can edit the control program according to the actual route planning, and enhances the control direction ability of the bionic fish. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic view of a flexible electric bionic fish fin structure;

[0019] Figure 2 is a schematic view of a swing driving part structure;

[0020] Figure 3 is a schematic view of a fin twisting mechanism structure.

[0021] The figure legend: 1-first triangular frame, 2-elastic belt, 3-elastic rope, 4-cross beam, 5-tail end triangular frame, 6-fish tip, 7-rack, 8-gear, 9-first motor, 10-base, 11-support frame, 12-hinge, 13-second motor, 14-long shaft, 15-universal joint, 16-bearing assembly, 17-fixing seat. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the present application is further described in detail below in combination with examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application. Figure 1 The view direction is that the first end is close to the head of the bionic fish, the tail end is close to the tail of the bionic fish, the front end is close to the fish tip side along the fin direction, and the rear end is close to the fin root side.

[0023] As shown in the drawings, the first end triangular frame 1 is fixed on the base 10, the elastic belt 2 is fixed on the first end triangular frame 1, the elastic rope 3 is fixed on the elastic belt 2, the cross beam 4 is fixed on the elastic rope 3, the tail end triangular frame 5 is fixed on the cross beam 4, the fish tip 6 is fixed on the tail end triangular frame 5, the rack 7 is fixed on the fish tip 6, the gear 8 is fixed on the rack 7, the first motor 9 is fixed on the base 10, the support frame 11 is fixed on the first motor 9, the hinge 12 is fixed on the support frame 11, the second motor 13 is fixed on the hinge 12, the long shaft 14 is fixed on the second motor 13, the universal joint 15 is fixed on the long shaft 14, the bearing assembly 16 is fixed on the universal joint 15, and the fixing seat 17 is fixed on the bearing assembly 16. Figure 1As shown, a flexible electric bionic fish fin includes a fin part and a motor driving part, the fin part is wrapped with a bionic skin, and is installed on the main frame of a bionic robot through a base 10. The base 10 is a combined plate structure, and various structural members fixed thereon are arranged reasonably to fix the positions of the structural members relative to the main frame of the bionic robot. The fin part includes a frame structure, a fin part swinging mechanism and a fin part twisting mechanism. The fin part swinging mechanism is driven by two flexible elastic belts 2, and the two elastic belts 2 are driven by a swinging driving part installed on the base 10. Figure 2 As shown, the swinging driving part includes a first motor 9, a gear 8 and a rack 7. The gear 8 is installed on the output shaft of the first motor 9, and is driven to rotate by the first motor 9, so as to drive the two racks 7 on the upper side and the lower side to reciprocate, respectively. The racks 7 are fixed on the elastic belts 2, so as to drive the elastic belts 2 to reciprocate in opposite directions at the same speed along the fin direction, thereby driving the fin part to imitate the up-and-down swinging of a fish fin. The elastic belts 2 are flexible belt bodies with rigidity, and the cross-sectional area of the elastic belts 2 in the length direction is variable. The cross-sectional area is maximum at the fin root, gradually decreases along the fin direction, and is minimum at the fin tip 6. A support frame 11 is hinged between the two elastic belts 2. The elastic belts 2 are located at the upper and lower ends of the support frame 11, and are connected to one side of a hinge 12 of the support frame 11.

[0024] As shown, Figure 1 The frame structure includes a rigid fin type frame, the support frame 11 and the fin tip 6. Lightweight and high-strength materials are adopted, and holes for weight reduction are dug in the frame structure. The rigid fin type frame is a plurality of rigid fin type frames arranged in parallel and at equal intervals along the fin direction. The first end and the tail end of each rigid fin type frame are triangular frames with an arc, which are used to imitate the cross-sectional shape of a fish fin at the position. The tail side of the first end triangular frame 1 is connected with the support frame 11, and the support frame 11 is connected with the tail end triangular frame 5 through a cross beam 4. The rigid fin type frame is maximum at the fin root, and gradually decreases along the fin direction. The area surrounded by the outer contour of each rigid fin type frame is linearly related to the cross-sectional area of the elastic belt 2 at the connection position of the rigid fin type frame. Independent support frames 11 are arranged between the adjacent two rigid fin type frames. All the support frames 11 are parallel and have geometric centers on the same straight line. The support frame 11 is a rectangular frame with the hinges 12 fixed on the upper and lower ends. The fin tip 6 is integrally connected with the first side of the two rigid fin type frames through a flat plate, so as to achieve the bionic effect of the fin tip.

[0025] As shown, Figure 3As shown, the fin torsion mechanism includes a universal joint 15 in the fin and a long shaft 14 connected by the universal joint 15, the fin torsion mechanism passes through the hole in the support frame 11 along the fin direction, the long shaft 14 connected by the universal joint 15 is driven by the torsion drive part installed on the base 10, the torsion drive part includes a second motor 13, the second motor 13 connects one end of the long shaft 14 to transmit the torsion force to the fin tip through the long shaft 14 and the universal joint 15, so that the fin is twisted around the root. The long shaft 14 is a coaxial multi-section structure, connected with multiple universal joints 15, along the fin direction, the rear end of the first section of the long shaft at the fin root is connected with the second motor 13, the front end is hinged with the first universal joint, the front end of the first universal joint is hinged with the second section of the long shaft, the front end of the second section of the long shaft is hinged with the second universal joint... in this order until the rear end of the universal joint 15 at the front end is hinged with the long shaft 14, and the front end is connected with the fixed seat 17 fixed on the fin tip 6 or the support frame 11 closest to the fin tip 6, each long shaft 14 is supported by a bearing assembly 16, the bearing seat of the bearing assembly 16 is fixed on the support frame 11, the universal joint 15 is rotatable in the radial direction and extendable in the axial direction, so that the universal joints 15 have relative sliding ability along the extension direction of the long shaft 15.

[0026] As shown, Figure 1 The rigid fin type frame is elastically connected, the elastic connection is that the elastic ropes 3 pass through the rigid fin type frame in turn along the fin direction and are connected with the rigid fin type frame, the elastic ropes 3 are two, which are respectively located on the center line of the fin and the tail side of the fin. The elastic connection cooperates with the fin oscillation mechanism to complete the coherent oscillation of the whole fin, which not only avoids the tail end of the fin from showing a scattered posture when the head end of the fin is driven by the fin oscillation mechanism, but also makes the tail end of the fin soft and better imitates the bionics effect.

[0027] In order to improve the buoyancy, a plurality of buoyancy blocks are arranged inside the fin to provide buoyancy, the buoyancy blocks are installed on the triangular frame 1 at the head end, the triangular frame 5 at the tail end and the cross beam 4.

[0028] The action principle is as follows: action one: the first motor 9 drives the gear 8 to rotate, and then the two racks 7 meshed with the gear 8 on the upper side and the lower side reciprocate respectively, the racks 7 are fixed on the elastic belts 2, so that the elastic belts 2 reciprocate in opposite directions and at opposite speeds along the fin direction, thereby driving the fin to imitate the up-down oscillation of the fish fin. Action two: the second motor 13 connects one end of the long shaft 14 to transmit the torsion force to the fin tip 6 through the long shaft 14 and the universal joint 15, so that the fin is twisted around the root. The up-down oscillation of the fin provides the swimming of the bionic fish in the forward direction, the faster the oscillation, the faster the swimming speed, the torsion of the fin provides the control of the swimming direction of the bionic fish, and the two work together to make the bionic fish swim flexibly and freely, and the bionic effect is realistic.

[0029] The above is the specific embodiment of the present application and the technical principle used, any modification and equivalent transformation based on the technical solution of the present application should be included in the protection scope of the present application.

Claims

1. A flexible electrically powered biomimetic fish fin, characterized by: The fin part and motor driving part are installed on the main frame of the bionic robot through the base, the fin part includes frame structure, fin part swing mechanism and fin part twist mechanism, the fin part swing mechanism is driven by two elastic belts with flexibility, the two elastic belts are synchronously driven by the motor driving part installed on the base, reciprocate in opposite direction and speed along the fin direction, the frame structure is hinged between the two elastic belts, the fin part twist mechanism includes universal joint in the fin part and long shaft connected through the universal joint, the long shaft connected through the universal joint is driven by the motor driving part installed on the base to twist the fin part around the root, the long shaft is coaxial multi-section structure, connected with multiple universal joints, the rear end of the first section long shaft of the fin root is connected with the motor driving part along the fin direction, the front end is hinged with the first universal joint, the front end of the first universal joint is hinged with the second section long shaft, the front end of the second section long shaft is hinged with the second universal joint, and the connection is sequentially continued until the rear end of the front end universal joint is hinged with the long shaft, and the front end is connected with the fin tip, each long shaft is fixed on the frame structure through bearing support bearing seat through bearing assembly, the universal joint is rotatable along the radial direction and retractable along the axial direction, the elastic belt is a flexible belt body with rigidity, the cross-sectional area of the elastic belt in the length direction is variable, the cross-sectional area is maximum at the fin root and gradually decreases along the fin direction, and the cross-sectional area is minimum at the fin tip, the frame structure includes rigid fin type frame, support frame and fin tip, the rigid fin type frame is multiple rigid fin type frames arranged in parallel and at equal intervals along the fin direction, the first and last ends of each rigid fin type frame are triangular frames with curvature, the tail side of the first end triangular frame is connected with the support frame, the support frame is connected with the tail end triangular frame through a cross beam, the rigid fin type frame is maximum at the fin root and gradually decreases along the fin direction, independent support frames are arranged between the two adjacent rigid fin type frames, all the support frames are parallel and the geometric centers are on the same straight line, the support frame is a rectangular frame with hinges fixed on the upper and lower ends, the fin tip is integrally connected with two rigid fin type frame first sides through a flat plate, the motor driving part includes twist driving part and swing driving part, the swing driving part includes first motor, gear and rack, the elastic belt reciprocates through the first motor driving gear and rack, the twist driving part includes second motor, one end of the second motor connects the long shaft to transmit the torsional force to the fin tip through the long shaft and universal joint.

2. The flexible electrically powered bionic fish fin according to claim 1, characterized in that: The rigid fin type frames are elastically connected, the elastic connection is elastic rope which passes through the rigid fin type frames along the fin direction and is elastically connected with the rigid fin type frames.

3. The flexible electrically powered bionic fish fin according to claim 1, characterized in that: The elastic belts are located on the upper and lower ends of the support frame, and the elastic belts are connected with one side of the hinges of the support frame.

4. The flexible electrically powered bionic fish fin according to claim 1, characterized in that: The fin part swing mechanism is located on the upper and lower surfaces of the support frame, and the fin part twist mechanism passes through the inner hole of the support frame.

5. The flexible electrically powered bionic fish fin according to claim 1, wherein: The area surrounded by the outer contour of each rigid fin type frame is linearly related to the cross-sectional area of the elastic belt at the connection position of the rigid fin type frame.

6. The flexible electrically powered bionic fish fin according to claim 2, characterized in that: The elastic connection has two, which are located on the center line of the fin part and the tail side of the fin part.

7. The flexible electrically powered bionic fish fin according to any one of claims 1-6, characterized in that: The outside of the fin part is wrapped with a bionic skin.

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