Bionic robotic fish based on magnetorheological damping mechanism

Abstract

The embodiment of the invention discloses a bionic robotic fish based on a magnetorheological damping mechanism, and belongs to the technical field of underwater robots, and the bionic robotic fish comprises a head cabin body, the head cabin body is provided with a pectoral fin structure, and the head cabin body is internally provided with a first driving device for driving the pectoral fin structure to deflect; the waist cabin is connected with the head cabin through a first transmission structure, and a second driving device used for driving the first transmission structure to drive the waist cabin to swing back and forth is arranged in the head cabin; the tail fin structure is connected with the waist cabin through a second transmission structure, and the second transmission structure comprises a magnetorheological damper, two torsion springs and a tail fin connecting part; the magneto-rheological damper is used for outputting damping torque to the tail fin connecting component. According to the bionic robotic fish based on the magneto-rheological damping mechanism provided by the embodiment of the invention, effective propulsion of the bionic robotic fish within a wide swing frequency range can be realized.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of underwater robots, in particular, to a bionic robotic fish based on a magneto-rheological damping mechanism. BACKGROUND

[0002] Underwater robots are increasingly becoming an important tool for ocean exploration and development. Traditional underwater propulsion methods generally use propellers, which have problems such as low efficiency, obvious noise, and insufficient concealment. With the in-depth application of bionics technology, new underwater robots simulate the wave propulsion mechanism of fish to achieve efficient underwater maneuvering capability. Such bionic robotic fish has become a focus of research and exploration for global researchers due to its excellent concealment performance, strong maneuvering flexibility, and low operating noise. SUMMARY

[0003] Embodiments of the present application provide a bionic robotic fish based on a magneto-rheological damping mechanism, aiming to achieve effective propulsion of the bionic robotic fish in a wide oscillation frequency range.

[0004] Embodiments of the present application provide a bionic robotic fish based on a magneto-rheological damping mechanism, comprising: a head cabin, a pectoral fin structure is arranged on the head cabin, and a first driving device for driving the pectoral fin structure to deflect is arranged in the head cabin; a waist cabin connected to the head cabin through a first transmission structure, and a second driving device for driving the first transmission structure to drive the waist cabin to reciprocate is arranged in the head cabin; a tail fin structure connected to the waist cabin through a second transmission structure, the second transmission structure comprising a magneto-rheological damper, two torsional springs, and a tail fin connecting component; wherein the tail fin connecting component comprises a first connecting end, a second connecting end, and a third connecting end, the first connecting end and the second connecting end are respectively arranged on both sides of the magneto-rheological damper, and the two torsional springs are respectively located between the first connecting end and the magneto-rheological damper and between the second connecting end and the magneto-rheological damper, and the third connecting end is fixedly connected to the tail fin structure; the magneto-rheological damper is used to output a damping torque to the tail fin connecting component.

[0005] Optionally, the magneto-rheological damper comprises a rotating shaft, a shell, and a shearing component, a stationary component, an enameled wire coil, and a magneto-rheological liquid in the shell; The rotating shaft is arranged in the shell and rotationally connected with the shell, the enameled coil is sleeved on the rotating shaft, the shearing component is arranged on the rotating shaft, the stationary component is arranged on the inner part of the shell, and the shearing component and the stationary component are distributed in overlap, the magnetorheological fluid is filled in the shell, and the magnetorheological fluid is filled between the shearing component and the stationary component; The first connecting end and the second connecting end are respectively connected at two ends of the rotating shaft, and the torsion spring is sleeved on the rotating shaft.

[0006] Optionally, the two ends of the rotating shaft are respectively provided with connecting cover plates, and the first connecting end and the second connecting end are respectively fixedly connected with the connecting cover plates. The two ends of the torsion spring are respectively connected with the connecting cover plates and the shell.

[0007] Optionally, a plurality of positioning protrusions are arranged on the inner wall of the shell, and the plurality of positioning protrusions are uniformly and spacedly distributed along the circumference of the shell. A plurality of positioning recesses are formed on the outer side wall of the stationary component, and the positioning recesses correspond to the positioning protrusions one by one.

[0008] Optionally, the shell comprises a first shell and a second shell, the second shell is formed with a containing cavity with an opening, the first shell is arranged on the second shell, and the first shell encloses the containing cavity. A boss is arranged on the surface of the first shell facing the containing cavity, the boss extends in a direction perpendicular to the first shell and away from the first shell, and the boss abuts against the stationary component.

[0009] Optionally, the shell is embedded in the waist cabin and fixedly connected with the waist cabin.

[0010] Optionally, the chest fin structure comprises a first chest fin and a second chest fin, and the first chest fin and the second chest fin are rotationally connected with the head cabin through a first connecting shaft and a second connecting shaft respectively. The first driving device comprises a servo steering machine, a first gear and a second gear. The output shaft of the servo steering machine is fixedly connected with the first gear, the first gear and the second gear are in mesh with each other, the second gear is fixedly connected with the first connecting shaft or the second connecting shaft, and the first connecting shaft and the second connecting shaft are connected through a shaft coupling.

[0011] Optionally, the outer sides of the first gear and the second gear are provided with gear cover plates.

[0012] Optionally, the first transmission structure comprises a fixing frame and a transmission output rotating shaft rotatably connected to the fixing frame, two ends of the transmission output rotating shaft are fixedly connected with connecting rods, and the two connecting rods are fixedly connected with the waist cabin. The second driving device comprises a direct-current brushless motor, a gear set, a motor shaft sleeve and a transmission member. An output end of the direct-current brushless motor is connected with the gear set, an output end of the gear set is connected with the motor shaft sleeve, the motor shaft sleeve is connected with the transmission member, and the transmission member is sleeved on the transmission output rotating shaft.

[0013] Optionally, an angle sensor is arranged on the magnetorheological damper.

[0014] Beneficial effects: The application provides a bionic robotic fish based on a magnetorheological damping mechanism, which comprises a head cabin, a waist cabin and a tail fin structure, wherein two sides of the head cabin are provided with pectoral fin structures, and a first driving device for driving the pectoral fin structures to deflect is arranged in the head cabin; the head cabin and the waist cabin are connected through a first transmission structure, and a second driving device for driving the waist cabin to reciprocate by the first transmission structure is further arranged in the head cabin; the waist cabin and the tail fin structure are connected through a second transmission structure, the second transmission structure comprises a magnetorheological damper, two torsional springs and a tail fin connecting component, and the magnetorheological damper is used for outputting a damping torque to the tail fin connecting component; in this way, the current intensity in the exciting coil is changed in real time by using the characteristic that the magnetorheological damping dynamic viscosity dynamically changes with the magnetic induction intensity, and the damping mechanism intensity is adjusted online, so that different swimming scenes can be adapted, and the swimming speed and the propulsion efficiency performance of the bionic robotic fish system in a wide swing frequency range are improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the application. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0016] Figure 1 is a structural schematic view of a bionic robotic fish based on a magnetorheological damping mechanism according to an embodiment of the application; Figure 2 is a structural schematic view of a pectoral fin structure and a first driving device in a bionic robotic fish based on a magnetorheological damping mechanism according to an embodiment of the application; Figure 3is a structural schematic view of a first transmission structure and a second driving device in a biomimetic robotic fish based on a magneto-rheological damping mechanism according to an embodiment of the present application; Figure 4 is a schematic view of a second transmission structure in a biomimetic robotic fish based on a magneto-rheological damping mechanism according to an embodiment of the present application; Figure 5 is a sectional schematic view of a second transmission structure in a biomimetic robotic fish based on a magneto-rheological damping mechanism according to an embodiment of the present application; Figure 6 is a comparison schematic view of average speeds of a biomimetic robotic fish based on a magneto-rheological damping mechanism and a biomimetic robotic fish in related art according to an embodiment of the present application; Figure 7 is a comparison schematic view of propelling efficiencies of a biomimetic robotic fish based on a magneto-rheological damping mechanism and a biomimetic robotic fish in related art according to an embodiment of the present application.

[0017] The reference signs are as follows: 1, head cabin; 2, waist cabin; 3, tail fin structure; 4, pectoral fin structure; 41, first pectoral fin; 42, second pectoral fin; 43, first connecting shaft; 44, second connecting shaft; 45, connecting bearing; 46, shaft coupling; 51, servo steering engine; 52, first gear; 53, second gear; 54, gear cover plate; 6, first transmission structure; 61, fixing frame; 62, transmission output shaft; 53; connecting rod; 71, direct current brushless motor; 72, gear set; 73, motor shaft sleeve; 74, transmission part; 8, second transmission structure; 81, magneto-rheological damper; 810, rotating shaft; 811, shell; 8111, first shell; 8112, second shell; 812, shearing part; 8121, first shearing disc; 8122, second shearing disc; 8123, third shearing disc; 8124, first shearing aluminum ring; 8125, second shearing aluminum ring; 813, stationary part; 8131, first stationary disc; 8132, second stationary disc; 8133, stationary aluminum ring; 814, enameled wire coil; 82, torsional spring; 83, tail fin connecting part; 831, first connecting end; 832, second connecting end; 833, third connecting end; 84, connecting cover plate; 9, boss; 10, angle sensor; 11, mounting bracket. DETAILED DESCRIPTION

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

[0019] In the related art, the propulsion device of the bionic robotic fish generally adopts a multi-joint series structure, and each joint is driven by an independent servo rudder. By coordinating the rotation angles of each rudder, a discrete fish wave curve can be simulated. Although increasing the number of rudders helps to improve the accuracy of motion simulation, this scheme also leads to the complexity of the overall structure of the bionic robotic fish, and the difficulty of coordinated control of each joint is significantly increased.

[0020] To solve the problems of high structural complexity and great control difficulty, researchers have proposed a rigid-flexible coupled bionic robotic fish mechanism, which adopts a servo rudder and a compliant tail driven by a flexible material. The flexible material has a significant advantage in simulating the continuity of fish swimming, and effectively transmits elastic energy during compression and stretching, effectively improving the propulsion efficiency of the bionic robotic fish.

[0021] However, due to the structural characteristics of the flexible material, the existing rigid-flexible coupled structure can only achieve optimal propulsion performance at a specific oscillation frequency. At a lower or higher oscillation frequency, the tail fin is subjected to too small and high strength hydrodynamic characteristics, the ideal fish body envelope oscillation law of the compliant tail is destroyed, and effective propulsion in a wide oscillation frequency range is difficult to achieve, limiting the practical application of the bionic robotic fish in marine environments.

[0022] Therefore, the embodiment of the present application proposes a bionic robotic fish based on the magnetic rheological damping mechanism, which aims to achieve effective propulsion of the bionic robotic fish in a wide oscillation frequency range.

[0023] Referring to Figure 1 , a bionic robotic fish based on the magnetic rheological damping mechanism provided by the embodiment of the present application is shown. The bionic robotic fish includes a head cabin 1, a waist cabin 2, and a tail fin structure 3.

[0024] Specifically, the head cabin 1 is one of the main components of the bionic robotic fish. The head cabin 1 is made of high-toughness nylon material. The head cabin 1 has a generally spindle shape, and the inside of the head cabin 1 is hollow. Referring to Figure 1 and Figure 2 , a pectoral fin structure 4 is arranged on the head cabin 1. In the embodiment of the present application, the pectoral fin structure 4 includes a first pectoral fin 41 and a second pectoral fin 42, and the first pectoral fin 41 and the second pectoral fin 42 are symmetrically distributed on both sides of the head cabin 1.

[0025] Referring to Figure 2As shown, the first pectoral fin 41 is rotatably connected with the head cabin 1 through a first connecting shaft 43, and the second pectoral fin 42 is rotatably connected with the head cabin 1 through a second connecting shaft 44. It can be understood that the rotatable connection of the first pectoral fin 41 and the second pectoral fin 42 can be achieved by providing a connecting bearing 45 on the first connecting shaft 43 and the second connecting shaft 44, and fixing the connecting bearing 45 with the head cabin 1. In addition, the first connecting shaft 43 and the second connecting shaft 44 extend into the head cabin 1.

[0026] Referring to Figure 2 As shown, a first driving device for driving the pectoral fin structure 4 to deflect is arranged in the head cabin 1. The first driving device includes a servo steering engine 51, a first gear 52 and a second gear 53. The output shaft of the servo motor is fixedly connected with the first gear 52, the second gear 53 is engaged with the first gear 52, and the second gear 53 is sleeved and fixedly connected on the first connecting shaft 43 or the second connecting shaft 44. In the embodiment of the present application, the second gear 53 is sleeved and fixedly connected on the first connecting shaft 43, and the first connecting shaft 43 and the second connecting shaft 44 are connected through a shaft coupling 46. In this way, the servo steering engine 51 can drive the first gear 52 to rotate, the first gear 52 drives the second gear 53 to rotate, and the second gear 53 can in turn drive the first connecting shaft 43 and the second connecting shaft 44 to rotate, thereby realizing the rotation of the first pectoral fin 41 and the second pectoral fin 42.

[0027] It should be noted that in the embodiment of the present application, the gear ratio of the first gear 52 and the second gear 53 is 1:1, and a gear cover plate 54 is arranged on the outside of the first gear 52 and the second gear 53. The gear cover plate 54 can avoid the internal wires of the head cabin 1 from being undesirably entangled with the first gear 52 / second gear 53, thereby reducing the occurrence of the situation that the pectoral fin structure 4 cannot normally swing.

[0028] Referring to Figure 1 As shown, the waist cabin 2 is connected with the head cabin 1 through a first transmission structure 6, the waist cabin 2 is made of high-toughness nylon material by shell printing, and the head cabin 1 is provided with a second driving device for driving the waist cabin 2 to reciprocate. It can be understood that the first driving device and the second driving device are located at different positions in the head cabin 1.

[0029] Specifically, referring to Figure 3 As shown, the first transmission structure 6 includes a fixed frame 61 and a transmission output rotating shaft 62 rotatably connected to the fixed frame 61, and the two ends of the transmission output rotating shaft 62 are fixedly connected with connecting rods 53, and the two connecting rods 53 are fixedly connected with the waist cabin 2. In the embodiment of the present application, the fixed frame 61 is arranged in the head cabin 1, the two ends of the transmission output rotating shaft 62 extend out of the head cabin 1, and the connecting rods 53 are also located outside the head cabin 1.

[0030] Referring to Figure 3 As shown in the figure, the second driving device includes a direct-current brushless motor 71, a gear set 72, a motor shaft sleeve 73 and a transmission member 74. Among them, the output end of the direct-current brushless motor 71 is connected with the gear set 72, the output end of the gear set 72 is connected with the motor shaft sleeve 73, the motor shaft sleeve 73 is fixedly connected with the transmission member 74, and the transmission member 74 is sleeved and fixedly connected on the transmission output shaft 62. At the same time, in the embodiment of the present application, the direct-current brushless motor 71 and the gear set 72 are fixed on the fixed frame 61, and the output end of the gear set 72 is sleeved in the fixed frame 61 and fixedly connected with the motor shaft sleeve 73. In this way, the direct-current brushless motor 71 can drive the motor shaft sleeve 73 to rotate reciprocatingly through the gear set 72, the motor shaft sleeve 73 drives the transmission member 74 to rotate reciprocatingly, the transmission member 74 drives the transmission output shaft 62 to rotate reciprocatingly, and the transmission output shaft 62 drives the waist cabin 2 to swing reciprocatingly through the connecting rod 53.

[0031] Referring to Figure 1 As shown in the figure, the tail fin structure 3 is connected with the waist cabin 2 through the second transmission structure 8, and the waist cabin 2 drives the tail fin structure 3 to swing in the process of reciprocating swing.

[0032] Referring to Figure 4 As shown in the figure, in the embodiment of the present application, the second transmission structure 8 includes a magnetorheological damper 81, two torsional springs 82 and a tail fin connecting component 83.

[0033] Specifically, referring to Figure 5 As shown in the figure, the magnetorheological damper 81 includes a rotating shaft 810, a shell 811, a shearing component 812, a stationary component 813, an enameled wire coil 814 and a magnetorheological liquid located in the shell 811. Among them, the shell 811 includes a first shell 8111 and a second shell 8112, the second shell 8112 forms a containing cavity with an opening, the shearing component 812, the stationary component 813, the enameled wire coil 814 and the magnetorheological liquid are located in the containing cavity, the first shell 8111 is arranged on the second shell 8112, and the first shell 8111 seals the containing cavity; a silicone rubber ring is arranged between the first shell 8111 and the second shell 8112 to ensure the sealing of the shell 811. At the same time, the shell 811 is embedded in and fixedly connected with the waist cabin 2. The first shell 8111 and the second shell 8112 are made of aluminum alloy material, and the whole shell 811 is annular.

[0034] Referring to Figure 5 As shown in the figure, the rotating shaft 810 is arranged in the shell 811 along the vertical direction, and both ends of the rotating shaft 810 are located outside the shell 811. Bearings are arranged on the rotating shaft 810 at positions where the first shell 8111 and the second shell 8112 are connected, and the rotating shaft 810 is rotatably connected with the shell 811 through the bearings.

[0035] Referring to Figure 5 As shown in the figure, the shearing component 812 includes a first shearing disc 8121, a second shearing disc 8122, a third shearing disc 8123, a first shearing aluminum ring 8124 and a second shearing aluminum ring 8125. Among them, the first shearing disc 8121 includes two sub-shearing discs, both of which are fixedly connected to the rotating shaft 810, and the enameled coil 814 is sleeved and fixedly connected to the rotating shaft 810, and at the same time the enameled coil 814 is located between the two sub-shearing discs. The second shearing disc 8122, the first shearing aluminum ring 8124, the third shearing disc 8123 and the second shearing aluminum ring 8125 are sequentially installed on the enameled coil 814 in the order from top to bottom, and the second shearing disc 8122 and the third shearing disc 8123, the third shearing disc 8123 and the lower sub-shearing disc form a reserved space.

[0036] Referring to Figure 5 As shown in the figure, the stationary component 813 includes a first stationary disc 8131, a second stationary disc 8132 and a stationary aluminum ring 8133. The first stationary disc 8131, the second stationary disc 8132 and the stationary aluminum ring 8133 are all fixedly connected to the inner side wall of the second shell 8112 811, and the first stationary disc 8131 is located in the reserved space between the second shearing disc 8122 and the third shearing disc 8123, the second stationary disc 8132 is located in the reserved space between the third shearing disc 8123 and the lower sub-shearing disc, and the stationary aluminum ring 8133 is located between the first stationary disc 8131 and the second stationary disc 8132. That is, in the embodiment of the application, the shearing component 812 and the stationary component 813 are distributed in the length direction of the rotating shaft 810. And the magnetorheological fluid is filled between the shearing component 812 and the stationary component 813.

[0037] Among them, the rotating shaft 810, the first shearing disc 8121, the second shearing disc 8122, the third shearing disc 8123, the first stationary disc 8131 and the second stationary disc 8132 all adopt high magnetic permeability electrical pure iron material, while the stationary aluminum ring 8133, the first shearing aluminum ring 8124 and the second shearing aluminum ring 8125 have very small magnetic permeability, so that as many magnetic lines as possible can pass through the effective action area between the multiple shearing discs and the multiple stationary discs, thereby effectively improving the torque range of the output of the magnetorheological damper 81. At the same time, the enameled coil 814 is nested on the outside of the rotating shaft 810, so that the magnetic lines form a closed loop outside the enameled coil 814, and the wires at both ends of the enameled coil 814 are led out from the through hole at the center of the rotating shaft 810. Changing the current intensity in the enameled coil 814 can change the internal magnetic induction intensity, thereby affecting the viscosity of the magnetorheological fluid, thereby effectively adjusting the output magnetorheological damping torque.

[0038] It can be understood that when different excitation currents are applied to the enameled coil 814, the magnetic induction intensity inside the magnetorheological damper 81 is changed, causing the magnetic particles in the magnetorheological liquid to form chain arrangements with different strengths between the inner and outer shear discs, that is, the viscosity value of the magnetorheological liquid is changed. The closer the chain arrangement is, the greater the corresponding damping viscosity is, so that when the shell 811 of the magnetorheological damper 81 drives the outer shear disc to rotate, the magnetorheological liquid with variable damping viscosity can generate damping torques with different strengths under the shearing action of the disc structure.

[0039] Referring to Figure 4 Meanwhile, the tail fin connecting component 83 can include a first connecting end 831, a second connecting end 832, and a third connecting end 833, the first connecting end 831 and the second connecting end 832 are fixedly connected with the two ends of the rotating shaft 810 respectively, and the third connecting end 833 is fixedly connected with the tail fin structure 3. In the embodiment of the present application, the tail fin connecting component 83 is composed of three plate bodies, and a plurality of bolt holes are formed on the plate bodies, so that the fixed connection of the tail fin connecting component 83 with the rotating shaft 810 and the tail fin structure 3 can be realized by using bolts.

[0040] Referring to Figure 5 As shown in the figure, the two ends of the rotating shaft 810 are respectively provided with a connecting cover plate 84, the first connecting end 831 and the second connecting end 832 are fixedly connected with the connecting cover plates 84 at the two ends of the rotating shaft 810 respectively. The two torsional springs 82 are located between the first connecting end 831 and the shell 811 and between the second connecting end 832 and the shell 811 respectively. It can be understood that the torsional spring 82 is sleeved on the rotating shaft 810, and the two ends of the torsional spring 82 are fixedly connected with the shell 811 and the connecting cover plate 84 respectively. When the rotating shaft 810 of the magnetorheological damper 81 rotates, the torsional spring 82 rotates, and the torsional spring 82 can play an elastic role and ensure that the tail fin structure 3 has a centering ability.

[0041] When the bionic robotic fish provided by the embodiment of the present application is used, the servo rudder 51 can be used to drive the first pectoral fin 41 and the second pectoral fin 42 to deflect, so that the bionic robotic fish has the ability to move in water; at the same time, the DC brushless motor 71 drives the waist cabin 2 to produce periodic reciprocating swing, and under the action of the magnetorheological damper 81 and the torsional spring 82, the tail fin structure 3 will be passively periodically swung when the waist cabin 2 reciprocating swings, so as to realize the underwater movement of the bionic robotic fish.

[0042] It is worth noting that the hydrodynamic force generated by the caudal fin structure 3 is the essential reason for the high propulsion performance of the biomimetic robotic fish. Therefore, the oscillation pattern of the caudal fin connecting component 83, which is directly connected to the caudal fin structure 3, plays a major role in high-maneuverability propulsion. Further analysis shows that the caudal fin connecting component 83 is subjected to the combined effects of magnetorheological damping torque, elastic torque, and hydrodynamic torque. At different oscillation frequencies, the caudal fin structure 3 experiences hydrodynamic torques of varying intensities. The hydrodynamic torque is smaller at low-frequency oscillations, while it significantly increases with increasing oscillation frequency.

[0043] At this point, by utilizing the dynamic change in dynamic viscosity of the magnetorheological damper 81 with the magnetic induction intensity, the current intensity in the enameled coil 814 can be changed in real time, and the damping mechanism strength can be adjusted online to adapt to different swimming scenarios. At lower oscillation frequencies, the inherent low viscosity of the magnetorheological fluid, combined with the relatively small hydrodynamic force on the tail fin structure 3, can form an ideal fish body envelope curve. As the oscillation frequency increases, the viscosity of the magnetorheological fluid is increased by enhancing the magnetic induction intensity inside the magnetorheological damper 81, thereby increasing the output torque of the magnetorheological damper 81. This, combined with the significantly enhanced hydrodynamic effect, can effectively optimize the oscillation phase and amplitude relationship of the tail fin structure 3, thereby improving the swimming speed and propulsion efficiency performance of the biomimetic robotic fish system over a wide oscillation frequency range.

[0044] Figure 6 A schematic diagram comparing the average speed of a biomimetic robotic fish in related technologies with that of the biomimetic robotic fish provided in this application embodiment is shown. Figure 6 It can be seen that the forward swimming speed of the biomimetic robotic fish initially increases and then gradually decreases with increasing oscillation frequency, indicating that there exists a specific frequency at which the biomimetic robotic fish achieves optimal swimming speed performance. Simultaneously, the biomimetic robotic fish without magnetorheological damping (corresponding to 0.0 A) exhibits superior swimming speed performance at low-frequency oscillations. Under greater magnetorheological damping (corresponding to 0.3 A and 0.6 A), the biomimetic robotic fish displays superior swimming speed performance in the mid-frequency oscillation range. With further increases in oscillation frequency, the biomimetic robotic fish exhibits optimal forward swimming speed performance under the highest magnetorheological damping condition (corresponding to 0.9 A). As the oscillation frequency range of the biomimetic robotic fish varies, the tail fin structure 3 experiences hydrodynamic forces of varying intensities. Therefore, by adjusting the damping strength of the magnetorheological damper 81, applying small and large magnetorheological damping during low-frequency and high-frequency oscillations respectively, the biomimetic robotic fish will exhibit superior swimming speed performance over a wide oscillation frequency range.

[0045] Figure 7A schematic diagram comparing the propulsion efficiency of biomimetic robotic fish in related technologies with that of the biomimetic robotic fish provided in this application embodiment is shown. Propulsion efficiency represents the energy consumed by the biomimetic robotic fish per unit mass to swim a unit distance; a smaller parameter value indicates stronger overall performance. Figure 7 It can be seen that the propulsion efficiency of the biomimetic robotic fish exhibits a U-shaped curve, first decreasing and then gradually increasing with increasing frequency, indicating that there exists a specific frequency at which the propulsion efficiency of the biomimetic robotic fish reaches its lowest point. Overall, the biomimetic robotic fish without magnetorheological damping (0.0 A) (i.e., the biomimetic robotic fish in related technologies) exhibits superior swimming efficiency at low-frequency oscillations, while the biomimetic robotic fish with the highest magnetorheological damping (0.9 A) demonstrates superior propulsion efficiency over a wide frequency range. Therefore, by adjusting the damping strength of the magnetorheological damper 81, the propulsion efficiency of the biomimetic robotic fish under different oscillation frequency scenarios can be effectively improved.

[0046] In one embodiment, a plurality of positioning protrusions are provided on the inner sidewall of the housing 811, and the plurality of positioning protrusions are evenly spaced along the circumference of the housing 811. At the same time, a plurality of positioning grooves are formed on the outer sidewall of the stationary component 813, and the positioning grooves correspond one-to-one with the positioning protrusions. The positioning protrusions and positioning grooves can be used to fix the stationary component 813 to the housing 811, and this connection method effectively saves the internal space of the housing 811 and enhances the integration of the entire device.

[0047] Reference Figure 5 As shown, in one embodiment, a boss 9 is provided on the surface of the first housing 8111 facing the receiving cavity. The boss 9 extends in a direction perpendicular to the first housing 8111 and away from the first housing 8111, and abuts against the stationary member 813. The boss 9 provides a positioning reference for the first housing 8111, allowing it to be accurately installed onto the second housing 8112. Furthermore, since the boss 9 abuts against the stationary member 813, it also restricts undesirable circumferential movement of the stationary member 813.

[0048] Reference Figure 4 As shown, in one embodiment, an angle sensor 10 is provided on the magnetorheological damper 81. Specifically, a mounting bracket 11 is provided on the housing 811, and the angle sensor 10 is fixed to the housing 811 by the mounting bracket 11. The angle sensor 10 can be used to detect the real-time rotation angle of the tail fin connecting component 83, so as to analyze the relationship between the phase and amplitude of the joint oscillation of the biomimetic robotic fish.

[0049] The bionic robotic fish based on the magneto-rheological damping mechanism provided by the embodiment of the application is integrated with a light-weight and high-integration magneto-rheological damper 81, can adjust the dynamic viscosity of the damping liquid online, avoids the problem of complex offline adjustment process, and can solve the problem that the existing bionic robotic fish cannot achieve optimal swimming speed and propulsion efficiency at a specific frequency.

[0050] It should be noted that each of the embodiments in the specification adopts a progressive manner for description, and each embodiment focuses on the difference from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0051] It should also be noted that in this paper, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, relationship terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations, nor can it be understood as indicating or implying relative importance. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or terminal device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or terminal device. Without more limitation, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or terminal device including the element.

[0052] The above describes the technical solutions provided by the present application in detail, and the principles and implementation modes of the present application are described by specific examples. The above description of the embodiments is only to help understanding the present application, and the content of the specification should not be understood as limiting the present application. Meanwhile, for those skilled in the art, according to the present application, there will be different forms of changes in specific implementation modes and application ranges, which do not need and cannot be exhaustively enumerated here, and the obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A biomimetic robotic fish based on magnetorheological damping mechanism, characterized in that, include: The head capsule is provided with a pectoral fin structure, and a first driving device for driving the pectoral fin structure to deflect is provided inside the head capsule. The waist compartment is connected to the head compartment via a first transmission structure, and the head compartment is provided with a second drive device for driving the first transmission structure to reciprocate the waist compartment. The tail fin structure is connected to the waist compartment via a second transmission structure, which includes a magnetorheological damper, two torsion springs, and a tail fin connecting component. The caudal fin connecting component includes a first connecting end, a second connecting end, and a third connecting end. The first connecting end and the second connecting end are respectively disposed on both sides of the magnetorheological damper, and two torsion springs are respectively located between the first connecting end and the magnetorheological damper and between the second connecting end and the magnetorheological damper. The third connecting end is fixedly connected to the caudal fin structure. The magnetorheological damper is used to output damping torque to the tail fin connecting component.

2. The biomimetic robotic fish based on magnetorheological damping mechanism according to claim 1, characterized in that: The magnetorheological damper includes a rotating shaft, a housing, and a shearing component, a stationary component, an enameled coil, and a magnetorheological fluid located within the housing; The rotating shaft passes through the housing and is rotatably connected to the housing. The enameled coil is sleeved on the rotating shaft. The shearing component is disposed on the rotating shaft. The stationary component is disposed inside the housing and is distributed overlappingly with the stationary component. The magnetorheological fluid fills the housing and is filled between the shearing component and the stationary component. The first connecting end and the second connecting end are respectively connected to the two ends of the rotating shaft, and the torsion spring is sleeved on the rotating shaft.

3. The biomimetic robotic fish based on magnetorheological damping mechanism according to claim 2, characterized in that: The two ends of the rotating shaft are respectively provided with connecting cover plates, and the first connecting end and the second connecting end are respectively fixedly connected to the connecting cover plates; The two ends of the torsion spring are connected to the connecting cover plate and the housing, respectively.

4. The biomimetic robotic fish based on magnetorheological damping mechanism according to claim 2, characterized in that: The inner wall of the housing is provided with a plurality of positioning protrusions, which are evenly spaced along the circumference of the housing. Multiple positioning grooves are formed on the outer side wall of the stationary component, and the positioning grooves correspond one-to-one with the positioning protrusions.

5. The biomimetic robotic fish based on magnetorheological damping mechanism according to claim 2, characterized in that: The housing includes a first housing and a second housing, the second housing having an opening in a receiving cavity, the first housing being disposed on the second housing and closing the receiving cavity; The first housing has a boss on its surface facing the receiving cavity. The boss extends in a direction perpendicular to the first housing and away from the first housing, and the boss abuts against the stationary component.

6. The biomimetic robotic fish based on magnetorheological damping mechanism according to claim 2, characterized in that: The shell is embedded in the waist compartment and is fixedly connected to the waist compartment.

7. The biomimetic robotic fish based on magnetorheological damping mechanism according to claim 1, characterized in that: The pectoral fin structure includes a first pectoral fin and a second pectoral fin, and the first pectoral fin and the second pectoral fin are rotatably connected to the head capsule via a first connecting shaft and a second connecting shaft, respectively. The first drive device includes a servo motor, a first gear, and a second gear; The output shaft of the servo motor is fixedly connected to the first gear, the first gear and the second gear mesh with each other, the second gear is fixedly connected to the first connecting shaft or the second connecting shaft, and the first connecting shaft and the second connecting shaft are connected by a coupling.

8. The biomimetic robotic fish based on magnetorheological damping mechanism according to claim 7, characterized in that: Gear cover plates are provided on the outer sides of the first gear and the second gear.

9. The biomimetic robotic fish based on magnetorheological damping mechanism according to claim 1, characterized in that: The first transmission structure includes a fixed frame and a transmission output shaft rotatably connected to the fixed frame. Connecting rods are fixedly connected to both ends of the transmission output shaft, and the two connecting rods are fixedly connected to the waist compartment. The second drive unit includes a brushless DC motor, a gear set, a motor bushing, and transmission components; The output end of the brushless DC motor is connected to the gear set, the output end of the gear set is connected to the motor bushing, the motor bushing is connected to the transmission component, and the transmission component is sleeved on the transmission output shaft.

10. The biomimetic robotic fish based on magnetorheological damping mechanism according to claim 1, characterized in that: An angle sensor is installed on the magnetorheological damper.

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