Bidirectional coupling fluctuation type propelling bionic manta ray based on eccentric wheel and connecting rod structure

Abstract

The invention relates to the field of bionic robots, and provides a bidirectional coupling fluctuation type propelling bionic manta ray based on an eccentric wheel connecting rod structure, the bidirectional coupling fluctuation type propelling bionic manta ray comprises a head mechanism, a tail mechanism and a body mechanism, and the head mechanism is connected to the body mechanism; the body mechanism comprises a silica gel pectoral fin and five frameworks, each framework is provided with two connecting rod mechanisms, each connecting rod mechanism comprises a driven rod, a connecting rod and an eccentric wheel, the eccentric wheel is provided with a wheel hole and a first connecting hole, the connecting rod is provided with a second connecting hole and a third connecting hole, the driven rod is provided with a fourth connecting hole and a fifth connecting hole, and the driven rod is in a bent shape. The second connecting hole is rotationally connected with the first connecting hole through a rotating shaft, the third connecting hole is rotationally connected with the fourth connecting hole through a rotating shaft, the fifth connecting hole is rotationally connected with the framework through a rotating shaft, and the silica gel pectoral fin is connected with all the driven rods. The tail mechanism comprises a fishtail, the fishtail is connected to one framework, and two driving mechanisms are arranged in the fishtail. According to the flexible silica gel pectoral fin, the reliability of the bionic manta ray is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bionic robots, in particular to a two-way coupled wave type propulsion bionic manta ray based on an eccentric wheel connecting rod structure. BACKGROUND

[0002] The traditional underwater robot adopts a propeller propulsion system, which is the most mainstream and mature technology at present, but it indeed has some inherent shortcomings. The traditional "propeller + rudder" or "vector propeller" mode has poor efficiency and maneuverability, and the propeller has low efficiency when running at low speed and high speed. When the robot is in suspension, low-speed observation and other scenes for fine work, it needs to frequently adjust the speed, which is high in energy consumption and insufficient in control precision. The traditional "propeller + rudder" or "vector propeller" mode needs a certain time and space to change direction. It is greatly limited in working in complex and narrow environments. In addition, the traditional propulsion mode also produces great noise and environmental impact. When the propeller speed is too high, a low pressure area will be generated on the back of the propeller blade, causing water vaporization to form cavitation bubbles, which will produce a huge noise when the cavitation bubbles burst, and the propeller will also produce mechanical vibration noise, forming noise pollution. This is a fatal shortcoming for marine biological research. The mechanical safety of the traditional method is poor, and the propeller has the risk of entanglement. The high-speed rotating propeller blade exposed to the outside is easy to be entangled by seaweed, fishing nets, cables and other foreign matters, which may cause the propeller to be stuck or even the whole robot to be trapped, which is one of the main risks of underwater operation.

[0003] Most of the existing bionic manta ray robots have rigid pectoral fins at the end, and the completely rigid fin tip may be at a non-optimal attack angle at many times. When the robot is disturbed by external water flow, the rigid structure may be whole jolted or shaken, and it is difficult to maintain stability and high propulsion efficiency in complex water flow. SUMMARY

[0004] In view of the technical problems in the background art, the present application aims to provide a two-way coupled wave type propulsion bionic manta ray based on an eccentric wheel connecting rod structure. The present application realizes the following technical scheme: A two-way coupled wave type propulsion bionic manta ray based on an eccentric wheel connecting rod structure, comprising a head mechanism, a tail mechanism and a body mechanism, the head mechanism being connected to the body mechanism; The body mechanism comprises a silica gel pectoral fin and five skeletons, and adjacent skeletons are connected to each other; Two connecting rod mechanisms are arranged on each frame, the connecting rod mechanism comprises a driven rod, a connecting rod and an eccentric wheel, the eccentric wheel is rotationally connected to the frame, a wheel hole and a connecting hole one are arranged on the eccentric wheel, a connecting hole two and a connecting hole three are arranged on the connecting rod, a connecting hole four and a connecting hole five are arranged on the driven rod, the driven rod is in a bent shape, the connecting hole two is rotationally connected with the connecting hole one through a rotating shaft, the connecting hole three is rotationally connected with the connecting hole four through a rotating shaft, the connecting hole five is rotationally connected with the frame through a rotating shaft, and the silica gel chest fin is connected with all the driven rods. The tail mechanism comprises a fish tail, the fish tail is connected to one of the frames, and two driving mechanisms are arranged in the fish tail and drive the eccentric wheels.

[0005] Preferably, a square groove is arranged on the driven rod.

[0006] Preferably, a buffer plate is connected to the driven rod, and the buffer plate is connected to the driven rod through a muscle body.

[0007] Preferably, the driving mechanism comprises a motor, a transmission shaft and a brass connecting shaft, the motor is connected to the fish tail, the output shaft of the motor is connected to the transmission shaft through the brass connecting shaft, and the transmission shaft is connected to the five eccentric wheels on one of the connecting rod mechanisms.

[0008] Preferably, a fish tail cover is connected to the fish tail.

[0009] Preferably, the head mechanism comprises a fish head, and the fish head is connected to one of the frames.

[0010] Preferably, a fish head cover is connected to the fish head.

[0011] Preferably, a drag reduction hole is arranged on the frame.

[0012] Preferably, a threading hole is arranged on the fish tail cover, and the power line and the data line of the motor pass through the threading hole.

[0013] Preferably, the shortest distance from the central axis of the wheel hole to the central axis of the connecting hole one is a; The shortest distance from the central axis of the connecting hole two to the central axis of the connecting hole three is b; The shortest distance from the central axis of the connecting hole four to the central axis of the connecting hole five is c; The shortest distance from the central axis of the wheel hole to the central axis of the connecting hole five is d; The relationship between a, b, c and d satisfies a²+d²=b²+c²; On the same connecting rod mechanism, the angle position of the adjacent two connecting hole ones in the circumferential direction of the eccentric wheel is different by 16° of the connecting hole one.

[0014] The present application has the following beneficial effects: The non-turning characteristic link structure of the original bionic manta ray swimming mode has simple structure, low noise compared with a traditional propeller driven, is convenient to maintain, and has no risk of being entangled by underwater organisms and underwater garbage, and meanwhile, the driven rod and the connecting rod can be modularly adjusted to change the length of the swing, meet different driving requirements, break the limitation of fixed phase, realize the periodic swing by using the 360° periodic rotation of the connecting rod, and reduce the driving difficulty. The joint driving mode with wave type propulsion is designed, the connecting hole one with an angle difference is used to realize the difference of each joint position, so that the swing of the joint has an angle difference from front to back, and meanwhile, the energy transmission efficiency of the joint group is high, the transmission of the wave is stable, the bionic manta ray stable propulsion mode can be realized, and the noise generated due to water flow disturbance is reduced. The self-deforming pectoral fin coupled in the chordwise and spanwise directions is designed, the trajectory of the wave type swing of the manta ray pectoral fin is well simulated, the contact area and the effective water pushing range of the pectoral fin and the water flow are maximized, and the propulsion efficiency of the bionic manta ray is improved; meanwhile, the bidirectional deforming pectoral fin can adjust the fin surface curvature in real time, the vortex loss generated in the movement of the traditional rigid fin or the single direction deforming fin is avoided, and the energy conversion efficiency is improved compared with a conventional propeller. The integrated fin tip based on the double flexible hinge can optimize the attack angle of the fin surface; in the swimming process of the bionic manta ray, the attack angle of the fin surface to the water flow is constantly changing; a completely rigid fin tip may be at a non-optimal attack angle at many times, and even a larger resistance is generated; the passively deformed fin tip can automatically adjust the bending shape under the action of the fluid, so that it is closer to the optimal angle for generating the maximum thrust in the whole wave cycle. The integrated fin tip based on the double flexible hinge improves the reliability of the bionic manta ray; the soft fin tip will bend and deform and then bounce back when colliding with an obstacle, so that the structural damage or jamming caused by hard collision is avoided; this greatly improves the survival ability and reliability of the robot in an unknown environment. BRIEF DESCRIPTION OF DRAWINGS

[0015] The application is further illustrated by using the drawings, but the embodiments in the drawings do not constitute any limitation on the application, and other drawings can be obtained by those skilled in the art without creative labor on the premise of not paying creative labor.

[0016] Figure 1 is a structure schematic view of a bionic manta ray based on an eccentric wheel link structure and bidirectional coupling wave type propulsion; Figure 2 is an internal structure view of a bionic manta ray based on an eccentric wheel link structure and bidirectional coupling wave type propulsion; Figure 3 is a structure schematic view of a head mechanism in the application; Figure 4 is a structural schematic diagram of the tail mechanism in the application; Figure 5 is a structural schematic diagram of the driven rod, connecting rod, eccentric wheel and skeleton in the application; Figure 6 is a structural schematic diagram of the connecting rod and eccentric wheel in the application; Figure 7 is a structural schematic diagram of the eccentric wheel in the application; Figure 8 is a structural schematic diagram of the connecting rod mechanism in the application; Figure 9 is a speed amplitude graph of the silica gel chest fin in the application; Figure 10 is an angular displacement amplitude graph of the driven rod in the application.

[0017] Reference signs: driven rod 1; connecting rod 2; eccentric wheel 3; skeleton 4; transmission shaft 5; brass connecting shaft 6; fish tail 7; fish tail cover 8; fish head 9; fish head cover 10; silica gel chest fin 11; square recess 12; buffer plate 13; motor 14; wheel hole 15; connecting hole one 16; connecting hole two 17; connecting hole three 18; connecting hole four 19; connecting hole five 20. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0019] In the description of the application, it should be noted that the orientations or positional relationships indicated by the terms “vertical”, “upper”, “lower”, “horizontal” and the like are based on the orientations or positional relationships shown in the drawings, and are only for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the application. In addition, “first”, “second”, “third”, “fourth” are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0020] It should be noted that in the description of the present application, unless otherwise explicitly specified and limited, the terms "arrange", "mount", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be connected through an intermediate medium, it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0021] As shown in Figures 1-10 A two-way coupling wave type propulsion bionic manta ray based on eccentric wheel connecting rod structure, comprising a head mechanism, a tail mechanism and a body mechanism, the head mechanism is connected to the body mechanism; The body mechanism comprises a silica gel pectoral fin 11 and five skeletons 4, adjacent skeletons 4 are connected to each other; Each skeleton 4 is provided with two connecting rod mechanisms, the connecting rod mechanism comprises a driven rod 1, a connecting rod 2 and an eccentric wheel 3, the eccentric wheel 3 is rotatably connected to the skeleton 4, the eccentric wheel 3 is provided with a wheel hole 15 and a connecting hole 16, the connecting rod 2 is provided with a connecting hole 17 and a connecting hole 18, the driven rod 1 is provided with a connecting hole 19 and a connecting hole 20, the driven rod 1 is in a bent shape, the connecting hole 17 is rotatably connected to the connecting hole 16 through a rotating shaft, the connecting hole 18 is rotatably connected to the connecting hole 19 through a rotating shaft, the connecting hole 20 is rotatably connected to the skeleton 4 through a rotating shaft, the silica gel pectoral fin 11 is connected to all the driven rods 1; The tail mechanism comprises a fish tail 7, the fish tail 7 is connected to one of the skeletons 4, the fish tail 7 is provided with two drive mechanisms, the drive mechanisms drive the eccentric wheels 3.

[0022] In a preferred embodiment of the present application, the driven rod 1 is provided with a square groove 12.

[0023] In a preferred embodiment of the present application, the driven rod 1 is provided with a square groove 12.

[0024] In a preferred embodiment of the present application, the drive mechanism comprises a motor 14, a transmission shaft 5 and a brass connecting shaft 6, the motor 14 is connected to the fish tail 7, the output shaft of the motor 14 is connected to the transmission shaft 5 through the brass connecting shaft 6, and the transmission shaft 5 is connected to the five eccentric wheels 3 of one of the connecting rod mechanisms.

[0025] In a preferred embodiment of the present application, the fish tail 7 is provided with a fish tail cover 8.

[0026] In a preferred embodiment of the present application, the head mechanism comprises a fish head 9, the fish head 9 is connected to one of the skeletons 4.

[0027] In a preferred embodiment of the present application, a fish head cover 10 is connected to the fish head 9.

[0028] In a preferred embodiment of the present application, a drag reduction hole is formed in the skeleton 4.

[0029] In a preferred embodiment of the present application, a threading hole is formed in the fish tail cover 8, and the power line and data line of the motor 14 pass through the threading hole.

[0030] In a preferred embodiment of the present application, the shortest distance from the axis of the wheel hole 15 to the axis of the connecting hole one 16 is a; The shortest distance from the axis of the connecting hole two 17 to the axis of the connecting hole three 18 is b; The shortest distance from the axis of the connecting hole four 19 to the axis of the connecting hole five 20 is c; The shortest distance from the axis of the wheel hole 15 to the axis of the connecting hole five 20 is d; The relationship between a, b, c, and d satisfies a²+d²=b²+c²; On the same connecting rod mechanism, the angle position of adjacent two connecting hole ones 16 in the circumferential direction of the eccentric wheel 3 is different by 16°.

[0031] Assembly process: Assembly of the transmission shaft 5: Insert the bearing into the ring at the circular clamping position of the skeleton 4, then insert the transmission shaft 5 into the bearing, and lock it with the clamping spring on both sides to prevent axial movement. Thus, the transmission shaft 5 that can rotate smoothly is assembled.

[0032] Assembly of the eccentric wheel 3, the connecting rod 2, and the driven rod 1: Arrange the eccentric wheel 3 so that the angle position of adjacent two connecting hole ones 16 in the circumferential direction of the eccentric wheel 3 is different by 16°, then insert them into the transmission shaft 5 in order, connect the connecting rod 2 and the eccentric wheel 3 by the rotating shaft, connect the connecting rod 2 and the driven rod 1 by the rotating shaft, insert the clamping spring, and the driven rod 1 generates a phase difference, showing a wave effect.

[0033] Assembly of the fish tail 7: Connect the transmission shaft 5 and the output shaft of the motor 14 with the brass connecting shaft 6, coat the output shaft of the motor 14 with a layer of silicone grease, bond the fish tail 7 and the fish tail cover 8 with hot melt glue, coat the joint gap with silicone grease, and lock it with screws. The connection between the motor 14 and the transmission shaft 5 is realized, and the waterproof effect of the motor 14 at the tail is achieved.

[0034] Assembly of the fish head 9: The fish head 9 and the fish head cover 8 are bonded with hot melt adhesive, the joint gap is coated with silicone grease, and the connecting holes of the fish head cover 10 are aligned with the connecting holes of the fish head 9 joint and locked with screws. The sealing and connection of the fish head 9 are realized.

[0035] Assembly of the silicone chest fin 11: The silicone chest fin 11 is cut to the appropriate size, and the silicone chest fin 11 is laid on the driven rod 1. The connecting holes at the end of the driven rod 1 are aligned and punched, and then the screws are inserted and locked with nuts. The silicone chest fin 11 is connected to all the driven rods 1.

[0036] Working principle: The application designs a two-way coupled wave type propulsion bionic manta ray based on an eccentric link mechanism. The propulsion is mainly realized by simulating the contraction movement of the manta ray's chest fin muscle. Through observation, it is found that the manta ray's chest fin adopts wave type propulsion, and the chest fin roughly swings in the form of a two-way coupled sine wave. The chest fin envelops the fluid and swings, generating a backward propulsion force. The sine wave has the advantage of stable wave form transmission, which can push the manta ray to move forward stably. Therefore, the application designs a link mechanism, which realizes the stable driving of the bionic manta ray through the two-way coupled deformation of the chord direction and the span direction of the link mechanism. The span direction sine type movement of the chest fin is realized through the non-quick-return characteristic of the link mechanism.

[0037] Through derivation, it is found that the link mechanism has no quick-return characteristic when the relationship between a, b, c, and d satisfies a²+d²=b²+c². Therefore, the application designs a link mechanism that satisfies the formula of no quick-return characteristic. In this way, when the driven rod 1 swings up and down, its linear velocity will change stably like a sine wave, realizing the span direction deformation.

[0038] Five linearly arranged span direction deformation link mechanisms form a group of link mechanisms. In this group of link mechanisms, each eccentric wheel 3 is connected through a transmission shaft 5 to make the eccentric wheels 3 rotate synchronously. Meanwhile, every two adjacent connecting holes one 16 are located at an angle difference of 16° in the circumferential direction of the eccentric wheel 3. In this way, the connecting hole one 16 closest to the fish head 9 and the connecting hole one 16 closest to the fish tail 7 are at an angle difference of 90°. Therefore, when the driven rod 1 closest to the fish head 9 swings to the highest point, the driven rod 1 closest to the fish tail 7 swings to the midpoint. When the driven rod 1 closest to the fish head 9 swings from the highest point to the midpoint, the driven rod 1 closest to the fish tail 7 swings from the midpoint to the highest point. Because the swing of the driven rod 1 has no quick-return characteristic, the speed of the rod from the highest point to the lowest point is the same. By analogy, the link mechanism produces chord direction sine type swing, forming a wave type two-way coupled link mechanism.

[0039] Meanwhile, the present application is provided with a plurality of square grooves 12 with a side length of 1.5 mm in the middle and rear section of the driven rod 1, so that the driven rod 1 can produce a certain amount of bending under the pressure of water flow, drive the silicone pectoral fin 11 to change, and achieve the purpose of optimizing the attack angle.

[0040] The square grooves 12 and the buffer plate 13 are collectively referred to as a double-flexible-hinge integrated fin tip, the square grooves 12 can be deformed to a certain extent under the action of water pressure, serving as a first flexible hinge, and the buffer plate 13 can also be deformed under the action of pressure, serving as a second flexible hinge.

[0041] The driven rod 1 has a buffer plate 13 at the end, the buffer plate 13 simulates the muscle of the manta ray fin tip, and is supported by an X-shaped rib body, and the square grooves 12 and the buffer plate 13 jointly act on the integrated fin tip to achieve a better deformation effect.

[0042] The driven rod 1 is printed by PLA material from the square grooves 12 to the end, and the reliability of the structure is verified through simulation analysis. The design running speed of the manta ray is v=0.5 m / s, the pectoral fin area is S=0.12 m², the drag coefficient is =1.2, the seawater density is =1×10³ kg / m³, and the formula D= × v²S is substituted, and the pressure D acting on the bionic manta ray pectoral fin is 18 N.

[0043] The force of 18 N is applied to the buffer plate 13 on the solidworks simulation, and the connecting rod is fixedly constrained, so that the stress diagram shown in the drawing is obtained, and the maximum equivalent stress in the diagram is 3.413× N / m², and the yield strength of the PLA material is about 60 Mpa, so that the stress of the material is less than 80% of the yield strength, and there is no risk of failure.

[0044] When the motor 14 inputs power, each driven rod 1 swings with a constant phase difference, drives the silicone pectoral fin 11 made of flexible material to generate a traveling wave along the chord direction, forms a spatial wave envelope, and makes the wave move backward, so as to push the bionic manta ray to swim forward, and realize wave-driven propulsion. When the two motors 14 rotate at the same speed, the transmission speed of the waves on both sides is consistent, and the bionic manta ray moves forward. When the rotation speed of one side is faster, the transmission speed of the wave on this side is faster, and the speed of the waves on both sides is different, so that the bionic manta ray turns, and the bionic manta ray can be controlled to turn left and right by controlling the differential motion of the motors.

[0045] The present application has the following beneficial effects: The non-turning characteristic link structure of the original bionic manta ray swimming mode has simple structure, low noise compared with a traditional propeller drive, is convenient to maintain, and has no risk of winding underwater organisms and underwater garbage, and meanwhile, the driven rod 1 and the connecting rod 2 can be modularly adjusted to change the length of swing, meet different driving requirements, break the limitation of a fixed phase, realize periodic swing in the mode of 360° periodic rotation of the connecting rod 2, and reduce driving difficulty; The joint driving mode with wave type propulsion is designed, the connecting hole 16 with an angle difference is adopted, the difference of each joint position is realized, so that the swing of the joint has an angle difference from front to back, meanwhile, the energy transmission efficiency of the joint group is high, the wave transmission is stable, the bionic manta ray stable propulsion mode can be realized, and noise generated due to water flow disturbance is reduced. The self-deforming pectoral fin coupled in the chordwise and spanwise directions is designed, the trajectory of the wave type swing of the manta ray pectoral fin is well simulated, the contact area and effective water pushing range of the pectoral fin and water flow are maximized, and the propulsion efficiency of the bionic manta ray is improved; meanwhile, the bidirectional deforming pectoral fin can adjust the fin surface curvature in real time, vortex loss generated in the movement of a traditional rigid fin or a single direction deforming fin is avoided, and the energy conversion efficiency is improved compared with a conventional propeller. The double flexible hinge integrated fin tip can optimize the attack angle of the fin surface, in the swimming process of the bionic manta ray, the attack angle of the fin surface to water flow is constantly changed; a completely rigid fin tip may be at a non-optimal attack angle at many times, and even a larger resistance is generated; the passively deformed fin tip can automatically adjust the bending shape under the action of fluid, so that the optimal angle for generating maximum thrust is approached in the whole wave cycle. The double flexible hinge integrated fin tip improves the reliability of the bionic manta ray, the soft fin tip will be bent and deformed and then rebounded when colliding with an obstacle, so that structural damage or jamming caused by hard collision is avoided; this greatly improves the survival ability and reliability of the robot in an unknown environment.

[0046] The components, modules, mechanisms and devices of the structure are not described in detail, are general standard parts or parts known to those skilled in the art, and the structure and principle thereof can be known by those skilled in the art through a technical manual or through a conventional experimental method.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited to the protection scope of the present application, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A two-way coupled wave motion bionic manta ray based on eccentric wheel linkage structure, characterized in that, The head mechanism, the tail mechanism and the body mechanism are connected to each other; The body mechanism comprises a silica gel chest fin (11) and five skeletons (4), and adjacent skeletons (4) are connected to each other; Each skeleton (4) is provided with two connecting rod mechanisms, and the connecting rod mechanism comprises a driven rod (1), a connecting rod (2) and an eccentric wheel (3), the eccentric wheel (3) is rotatably connected to the skeleton (4), the eccentric wheel (3) is provided with a wheel hole (15) and a connecting hole one (16), the connecting rod (2) is provided with a connecting hole two (17) and a connecting hole three (18), the driven rod (1) is provided with a connecting hole four (19) and a connecting hole five (20), the driven rod (1) is in a bent shape, the connecting hole two (17) is rotatably connected to the connecting hole one (16) through a rotating shaft, the connecting hole three (18) is rotatably connected to the connecting hole four (19) through a rotating shaft, the connecting hole five (20) is rotatably connected to the skeleton (4) through a rotating shaft, and the silica gel chest fin (11) is connected to all the driven rods (1). The tail mechanism comprises a fish tail (7), the fish tail (7) is connected to one of the skeletons (4), and the fish tail (7) is provided with two driving mechanisms inside.

2. A two-directional coupled wave propulsion biomimetic manta ray based on eccentric wheel linkage structure according to claim 1, characterized in that, The driven rod (1) is provided with a square groove (12).

3. A two-directional coupled wave propulsion biomimetic manta ray based on an eccentric wheel linkage structure according to claim 2, characterized in that, The driven rod (1) is connected with a buffer plate (13), and the buffer plate (13) is connected to the driven rod (1) through a muscle body.

4. A two-directional coupled wave propulsion biomimetic manta ray based on an eccentric wheel linkage structure according to claim 3, characterized in that, The driving mechanism comprises a motor (14), a transmission shaft (5) and a brass connecting shaft (6), the motor (14) is connected to the fish tail (7) inside, the output shaft of the motor (14) is connected to the transmission shaft (5) through the brass connecting shaft (6), and the transmission shaft (5) is connected to five eccentric wheels (3) on one of the connecting rod mechanisms.

5. A two-directional coupled wave propulsion biomimetic manta ray based on an eccentric wheel linkage structure according to claim 4, characterized in that, The fish tail (7) is connected with a fish tail cover (8).

6. A two-directional coupled wave propulsion biomimetic manta ray based on an eccentric wheel linkage structure according to claim 5, characterized in that, The head mechanism comprises a fish head (9), and the fish head (9) is connected to one of the skeletons (4).

7. A two-directional coupled wave propulsion biomimetic manta ray based on an eccentric wheel linkage structure according to claim 6, characterized in that, The fish head (9) is connected with a fish head cover (10).

8. A two-directional coupled wave propulsion biomimetic manta ray based on an eccentric wheel linkage structure according to claim 7, characterized in that, The skeleton (4) is provided with a drag reduction hole.

9. A two-directional coupled wave propulsion biomimetic manta ray based on an eccentric wheel linkage structure according to claim 8, characterized in that, The fish tail cover (8) is provided with a threading hole, and the power line and the data line of the motor (14) pass through the threading hole.

10. A bionic manta ray based on eccentric wheel linkage structure bidirectional coupled wave motion propelling according to any one of claims 1-9, characterized in that, The shortest distance from the central axis of the wheel hole (15) to the central axis of the connecting hole one (16) is a; The shortest distance from the central axis of the connecting hole two (17) to the central axis of the connecting hole three (18) is b; The shortest distance from the central axis of the connecting hole four (19) to the central axis of the connecting hole five (20) is c; The shortest distance from the central axis of the wheel hole (15) to the central axis of the connecting hole five (20) is d; The relationship among a, b, c and d satisfies a²+d²=b²+c²; On the same connecting rod mechanism, the angle position of adjacent two connecting hole ones (16) in the circumferential direction of the eccentric wheel (3) is different by 16°.

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