Underwater vehicle and variable amplitude biomimetic propulsion design method

Abstract

The application discloses an underwater vehicle and a variable-amplitude bionic propulsion design method, and relates to the technical field of robots. The underwater vehicle comprises a shell, a bionic tail fin, a first driving mechanism and a second driving mechanism. The shell has a tail part. The bionic tail fin is rotationally arranged on the tail part through a rotating shaft. The first driving mechanism is arranged in the shell. The first driving mechanism comprises a driving unit, a transmission assembly and a swing arm which are sequentially connected. The swing arm is hingedly connected with the rotating shaft and movably connected with the transmission assembly. The swing arm is arranged at an angle with the rotating shaft. The driving unit can drive the rotating shaft to reciprocatingly rotate through the transmission assembly and the swing arm. The second driving mechanism is arranged in the shell and connected with the transmission assembly. The second driving mechanism can drive the transmission assembly to move towards the rotating shaft or away from the rotating shaft, so as to adjust the angle between the swing arm and the transmission assembly. The technical scheme provided by the application can solve the technical problem of poor adjustability of the underwater vehicle using the bionic tail fin for propulsion.

Description

Technical Field

[0001] The present invention relates to the field of robotics technology, and in particular to an underwater vehicle and a variable amplitude bionic propulsion design method. Background Art

[0002] Underwater vehicles (UVs) are devices capable of autonomously or remotely navigating underwater and performing specific tasks. They are widely used in various fields, including military, scientific research, and marine development. Bionic tail fin propulsion is widely used in underwater vehicles due to its advantages of low noise, no disruptive water disturbance, narrow size, high maneuverability, and adaptability to confined environments. However, the use of the flapping of bionic tail fins for propulsion in underwater vehicles has a technical problem of poor adjustability.

[0003] Therefore, it is necessary to provide a new underwater vehicle and variable amplitude bionic propulsion design method to solve the above technical problems. Summary of the Invention

[0004] The main purpose of the present invention is to provide an underwater vehicle and a variable amplitude bionic propulsion design method, aiming to solve the technical problem of poor adjustability of underwater vehicles using bionic tail fin propulsion.

[0005] To achieve the above-mentioned object, the present invention proposes an underwater vehicle comprising:

[0006] a housing having a tail portion;

[0007] A bionic tail fin, the bionic tail fin being rotatably disposed on the tail via a rotating shaft;

[0008] a first drive mechanism, the first drive mechanism being disposed within the housing and comprising a drive unit, a transmission assembly, and a swing arm connected in sequence, the swing arm being hinged to the rotating shaft and movably connected to the transmission assembly, the swing arm being arranged at an angle to the rotating shaft, and the drive unit being capable of driving the rotating shaft to reciprocate via the transmission assembly and the swing arm;

[0009] A second driving mechanism is disposed in the housing and connected to the transmission assembly; the second driving mechanism can drive the transmission assembly to move toward or away from the rotating shaft to adjust the angle between the swing arm and the transmission assembly.

[0010] In one embodiment, the transmission assembly includes a connecting frame, a shaft and a connecting rod hinged to each other, the shaft being rotatably mounted on the connecting frame, the output shaft of the drive unit being slidably mounted on the shaft and engaged with the shaft, the connecting rod being hinged to the swing arm, the connecting rod being arranged at an angle to the shaft and the swing arm;

[0011] The second driving mechanism is connected to the connecting frame and can drive the connecting frame to move along the central axis of the output shaft of the driving unit, thereby driving the shaft to move toward or away from the rotating shaft to adjust the angle between the swing arm and the shaft.

[0012] In one embodiment, the second driving mechanism includes a driving member and a cam provided on the driving member, wherein the cam abuts against a side of the connecting frame facing away from the driving unit; the driving member can drive the cam to rotate to drive the connecting frame to move along the central axis direction of the output shaft of the driving unit.

[0013] In one embodiment, the transmission assembly includes a connecting frame, a shaft and a connecting block, the shaft is rotatably provided on the connecting frame, the output shaft of the drive unit is slidably provided on the shaft and engaged with the shaft, the connecting block is provided on the shaft, the first end of the swing arm is hinged to the rotating shaft, the second end of the swing arm is slidably provided on the connecting block, and the sliding direction of the second end of the swing arm is provided at an angle to the central axis direction of the shaft;

[0014] The second driving mechanism is connected to the connecting frame and can drive the connecting frame to move along the central axis direction of the output shaft of the driving unit, thereby driving the shaft to move toward or away from the rotating shaft, so as to drive the second end of the swing arm to slide on the connecting block and adjust the angle between the swing arm and the shaft.

[0015] In one embodiment, the second driving mechanism includes a driving member and a screw rod provided on the driving member, and the connecting frame is engaged with the screw rod; the driving member can drive the screw rod to rotate to drive the connecting frame to move along the central axis direction of the output shaft of the driving unit.

[0016] In one embodiment, the connecting block is provided with a sliding groove, the second end of the swing arm is slidably disposed in the sliding groove, and an extension direction of the sliding groove is arranged at an angle to an extension direction of the shaft.

[0017] In one embodiment, the shell further has a head and a main body connecting the head and the tail, and the underwater vehicle further includes a bionic pectoral fin and a third driving mechanism, wherein the third driving mechanism is disposed in the shell, and the bionic pectoral fin is rotatably disposed on the third driving mechanism and extends out of the main body; the third driving mechanism is used to drive the bionic pectoral fin to swing around its rotation axis, and to drive the end of the bionic pectoral fin away from the main body to rotate toward or away from the head.

[0018] In one embodiment, the third driving mechanism includes a bracket, a first servo, a second servo and a transmission member arranged on the bracket, and the bionic pectoral fin is rotatably arranged on the transmission member; the first servo drives the bionic pectoral fin to rotate around the vertical direction of the transmission member through the transmission member, so that the bionic pectoral fin rotates away from one end of the main body toward or away from the head, and the second servo drives the bionic pectoral fin to swing around its rotation axis through the transmission member.

[0019] In one embodiment, the transmission member includes a housing and a helical gear disposed in the housing, one end of the bionic pectoral fin is disposed in the housing and meshes with the helical gear, and the bracket is further provided with a first synchronous wheel, a second synchronous wheel, and a first shaft and a second shaft coaxially nested, the first shaft connecting the first synchronous wheel and the housing, and the second shaft connecting the second synchronous wheel and the helical gear;

[0020] The first servo drives the first synchronous wheel to rotate through the first synchronous belt, thereby driving the shell to rotate around the vertical direction of the transmission member to drive the bionic pectoral fin to rotate around the vertical direction of the transmission member; the second servo drives the second synchronous wheel to rotate through the second synchronous belt, thereby driving the bevel gear to rotate to drive the bionic pectoral fin to swing around its rotation axis.

[0021] In addition, the present invention also proposes a variable amplitude bionic propulsion design method, which is applied to the underwater vehicle as described above. The variable amplitude bionic propulsion design method includes:

[0022] Obtain the angle between the output shaft of the driving unit and the horizontal plane when it rotates, the radius of the circle when the end of the swing arm away from the rotating shaft performs a circular motion in the vertical plane, and the projected length from the end of the swing arm connected to the rotating shaft to the other end of the swing arm in the horizontal plane;

[0023] The swing angle of the bionic tail fin is obtained according to a preset formula, which is:

[0024]

[0025] Among them, γ is the angle between the output shaft of the driving unit and the horizontal plane when it rotates, R is the radius of the circle when the end of the swing arm away from the rotating shaft makes a circular motion in the vertical plane, θ is the swing angle of the bionic tail fin, and d is the projected length from the end of the swing arm connected to the rotating shaft to the other end of the swing arm on the horizontal plane.

[0026] The technical solution of the present invention utilizes a second drive mechanism for driving the transmission assembly toward or away from the rotating shaft. By adjusting the angle between the swing arm and the transmission assembly, the swing amplitude of the bionic tail fin can be adjusted, thereby enhancing the adjustability of the underwater vehicle. In this embodiment, the first drive mechanism is used to drive the bionic tail fin to swing, providing the propulsion required for the underwater vehicle to move forward. The drive unit drives the swing arm to rotate through the transmission assembly, causing the end of the swing arm away from the rotating shaft to perform circular motion in a vertical plane, thereby driving the rotating shaft to reciprocate, causing the bionic tail fin to swing back and forth, providing the propulsion required for the underwater vehicle to move forward. The second drive mechanism drives the transmission assembly toward or away from the rotating shaft, thereby adjusting the distance between the rotating shaft and the transmission assembly. This adjusts the angle between the swing arm and the transmission assembly, thereby adjusting the radius of the circular motion of the end of the swing arm away from the rotating shaft in a vertical plane, and adjusting the angle of the reciprocating rotation of the rotating shaft. This allows the swing amplitude of the bionic tail fin to be adjusted, enhancing the adjustability of the underwater vehicle. Specifically, when it is necessary to reduce the swimming speed of the underwater vehicle and make it swim slowly, the first driving mechanism is controlled to operate so as to reduce the swinging frequency of the bionic tail fin; at the same time, the second driving mechanism is controlled to drive the transmission assembly to move in a direction away from the rotating shaft, so as to increase the distance between the rotating shaft and the transmission assembly, thereby reducing the radius of the circle when the end of the swing arm away from the rotating shaft makes a circular motion in the vertical plane, and reducing the angle of the rotating shaft when it rotates back and forth, so as to reduce the swing amplitude of the bionic tail fin, thereby making the swing amplitude and swing frequency of the bionic tail fin more adaptable, thereby reducing the swimming speed of the underwater vehicle. When it is necessary to increase the swimming speed of the underwater vehicle and make it swim quickly, the first driving mechanism is controlled to operate so as to increase the swinging frequency of the bionic tail fin; at the same time, the second driving mechanism is controlled to drive the transmission assembly to move in the direction close to the rotating shaft, so as to reduce the distance between the rotating shaft and the transmission assembly, thereby increasing the radius of the circle when the end of the swing arm away from the rotating shaft makes a circular motion in the vertical plane, and increasing the angle of the rotating shaft during reciprocating rotation, so as to increase the swing amplitude of the bionic tail fin, thereby making the swing amplitude and swing frequency of the bionic tail fin more adaptable, thereby improving the swimming speed of the underwater vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0028] Figure 1 A schematic structural diagram of an underwater vehicle according to an embodiment of the present invention;

[0029] Figure 2 A schematic structural diagram of a first driving mechanism and a second driving mechanism in an embodiment of the present invention;

[0030] Figure 3 A schematic structural diagram of a first driving mechanism and a second driving mechanism in another embodiment provided by the present invention;

[0031] Figure 4 A schematic structural diagram of the bionic pectoral fin and the third driving mechanism in one embodiment of the present invention;

[0032] Figure 5 A schematic diagram of various parameters in a calculation method in an embodiment of the present invention.

[0033] Description of Figure Numbers:

[0034] 100. Housing; 110. Tail; 120. Head; 130. Main body; 200. Bionic tail fin; 210. Rotating shaft; 300. First driving mechanism; 310. Driving unit; 320. Transmission assembly; 321. Connecting frame; 322. Shaft; 323. Connecting rod; 324. Connecting block; 3241. Slide; 330. Swing arm; 331. Spherical block; 400. Second driving mechanism; 410. Driving member; 420. Cam; 430. Screw; 500. Bionic pectoral fin; 600. Third driving mechanism; 610. Bracket; 611. First synchronous wheel; 612. Second synchronous wheel; 620. First servo; 630. Second servo; 640. Transmission member; 641. Housing; 642. Bevel gear; 700. Oil seal mechanism.

[0035] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that meet both A and B.

[0039] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0040] An underwater vehicle is a device that can navigate autonomously or remotely underwater and perform specific tasks. Bionic tail fin propulsion is widely used in underwater vehicles due to its advantages such as low noise, no destructive water disturbance, narrow and long body, high maneuverability and adaptability to narrow environments. During the actual research and development process, researchers found that the swimming of underwater vehicles propelled by bionic tail fins mainly depends on the high-frequency swinging of the bionic tail fin, and the swimming speed is determined by factors such as the swing frequency, swing amplitude and shape and size of the bionic tail fin. However, most traditional bionic tail fins can only swing at a fixed amplitude, which will affect the adjustability of underwater vehicles when using bionic tail fins for propulsion. Among them, the above-mentioned adjustability refers to the ability of underwater vehicles to adjust the motion characteristics of the swing when using the swing of the bionic tail fin for propulsion.

[0041] The present invention provides an underwater vehicle, aiming to solve the technical problem of poor adjustability of underwater vehicles propelled by bionic tail fins.

[0042] See also Figures 1 to 3In one embodiment of the present invention, the underwater vehicle includes a housing 100, a bionic tail fin 200, a first driving mechanism 300, and a second driving mechanism 400. The housing 100 has a tail portion 110. The bionic tail fin 200 is rotatably disposed on the tail portion 110 via a rotating shaft 210. The first driving mechanism 300 is disposed within the housing 100. The first driving mechanism 300 includes a driving unit 310, a transmission assembly 320, and a swing arm 330 connected in sequence. The swing arm 330 is hinged to the rotating shaft 210 and movably connected to the transmission assembly 320. The swing arm 330 is disposed at an angle to the rotating shaft 210. The driving unit 310 can drive the rotating shaft 210 to reciprocate through the transmission assembly 320 and the swing arm 330. The second driving mechanism 400 is disposed within the housing 100 and is connected to the transmission assembly 320. The second driving mechanism 400 can drive the transmission assembly 320 to move toward or away from the rotating shaft 210 to adjust the angle between the swing arm 330 and the transmission assembly 320.

[0043] The technical solution of the present invention utilizes a second drive mechanism 400 for driving the transmission assembly 320 toward or away from the rotating shaft 210. By adjusting the angle between the swing arm 330 and the transmission assembly 320, the swing amplitude of the bionic tail fin 200 can be adjusted, thereby enhancing the adjustability of the underwater vehicle. In this embodiment, the first drive mechanism 300 is used to drive the bionic tail fin 200 to swing, providing the propulsion required for the underwater vehicle to move forward. The drive unit 310, via the transmission assembly 320, drives the swing arm 330 to rotate, causing the end of the swing arm 330 away from the rotating shaft 210 to perform circular motion in a vertical plane. This in turn drives the rotating shaft 210 to rotate back and forth, driving the bionic tail fin 200 to swing back and forth, providing the propulsion required for the underwater vehicle to move forward. The second driving mechanism 400 drives the transmission component 320 to move toward or away from the rotating shaft 210, adjusts the distance between the rotating shaft 210 and the transmission component 320, and can adjust the angle between the swing arm 330 and the transmission component 320, thereby adjusting the radius of the circle when the end of the swing arm 330 away from the rotating shaft 210 makes a circular motion in the vertical plane, and adjusts the angle of the rotating shaft 210 when it rotates back and forth. In this way, the swing amplitude of the bionic tail fin 200 can be adjusted, thereby improving the adjustability of the underwater vehicle. Specifically, when it is necessary to reduce the swimming speed of the underwater vehicle and make it swim slowly, the first driving mechanism 300 is controlled to operate to reduce the swinging frequency of the bionic tail fin 200; at the same time, the second driving mechanism 400 is controlled to drive the transmission assembly 320 to move in a direction away from the rotating shaft 210, so that the distance between the rotating shaft 210 and the transmission assembly 320 can be increased, thereby reducing the radius of the circle when the end of the swing arm 330 away from the rotating shaft 210 makes a circular motion in the vertical plane, and reducing the angle of the rotating shaft 210 when it rotates back and forth, so that the swing amplitude of the bionic tail fin 200 is reduced, and the swing amplitude and swing frequency of the bionic tail fin 200 can be made more adaptable, thereby reducing the swimming speed of the underwater vehicle. When the underwater vehicle's swimming speed needs to be increased, the first drive mechanism 300 is controlled to operate, thereby increasing the swing frequency of the bionic tail fin 200. Simultaneously, the second drive mechanism 400 is controlled to drive the transmission assembly 320 toward the rotating shaft 210. This reduces the distance between the rotating shaft 210 and the transmission assembly 320, thereby increasing the radius of the circular motion of the end of the swing arm 330 away from the rotating shaft 210 in the vertical plane, and increasing the angle of the rotating shaft 210 during reciprocating rotation. This increases the swing amplitude of the bionic tail fin 200, thereby making the swing amplitude and swing frequency of the bionic tail fin 200 more compatible, thereby increasing the swimming speed of the underwater vehicle. This underwater vehicle has applications in robotic fish, underwater robots that use the swinging of the bionic tail fin 200 for propulsion, and other technical fields.

[0044] It should be noted that for underwater vehicles propelled by the bionic tail fin 200, the oscillation frequency of the bionic tail fin 200 determines the swimming speed of the underwater vehicle. However, bionic tail fins with different oscillation frequencies generally require different oscillation amplitudes to achieve maximum propulsion performance. The underwater vehicle primarily uses the oscillation of the bionic tail fin 200 to generate propulsion underwater, propelling the underwater vehicle forward. Specifically, if other factors such as the oscillation frequency, shape, and size of the bionic tail fin 200 remain the same, the greater the oscillation amplitude of the bionic tail fin 200, the larger the area swept underwater by the bionic tail fin 200, and the greater the propulsion generated. In addition, the underwater vehicle drives the transmission assembly 320 to move toward the direction close to the rotating shaft 210 through the second driving mechanism 400 to adjust the swing amplitude of the bionic tail fin 200. It can make the bionic tail fin 200 produce asymmetric flapping within one swing cycle of the bionic tail fin 200, that is, it can make one side of the bionic tail fin 200 swing greatly and the other side swing less, which can generate lateral force and thereby improve the steering performance of the underwater vehicle.

[0045] See also Figure 2 In one embodiment of the present invention, the transmission assembly 320 includes a connecting frame 321, a shaft 322 hingedly connected to each other, and a connecting rod 323. The shaft 322 is rotatably mounted on the connecting frame 321. The output shaft of the drive unit 310 slides through the shaft 322 and engages with the shaft 322. The connecting rod 323 is hingedly mounted to the swing arm 330, and the connecting rod 323 is disposed at an angle to the shaft 322 and the swing arm 330. Specifically, the drive unit 310 can drive the shaft 322 to rotate, thereby driving the connecting rod 323 to rotate about the central axis of the shaft 322, and driving the swing arm 330 to rotate about the central axis of the shaft 322, causing the end of the swing arm 330 away from the rotating shaft 210 to perform circular motion in a vertical plane, thereby driving the rotating shaft 210 to rotate back and forth, driving the bionic tail fin 200 to swing back and forth, and providing the propulsion required for the underwater vehicle to move forward. In this embodiment, the output shaft of the drive unit 310 is engaged with and passes through the shaft 322. When the second drive mechanism 400 drives the shaft 322 to move along the central axis of the output shaft of the drive unit 310, the shaft 322 remains engaged with the output shaft of the drive unit 310. In a specific embodiment, the output shaft of the drive unit 310 and the shaft 322 are coaxially arranged.

[0046] The second driving mechanism 400 is connected to the connecting frame 321 and can drive the connecting frame 321 to move along the central axis direction of the output shaft of the driving unit 310, and then drive the shaft 322 to move toward or away from the rotating shaft 210 to adjust the angle between the swing arm 330 and the shaft 322. In this embodiment, the second drive mechanism 400 drives the connecting frame 321 to move along the central axis of the output shaft of the drive unit 310, thereby driving the shaft 322 rotatably mounted on the connecting frame 321 to move along the central axis of the output shaft of the drive unit 310 toward or away from the rotating shaft 210. This allows the second drive mechanism 400 to adjust the distance between the shaft 322 and the rotating shaft 210, causing the connecting rod 323 and the swing arm 330 to rotate relative to each other, thereby adjusting the angle between the swing arm 330 and the shaft 322. This in turn adjusts the radius of the circular motion of the end of the swing arm 330 away from the rotating shaft 210 in a vertical plane, thereby adjusting the angle of the reciprocating rotation of the rotating shaft 210 and the swing amplitude of the bionic tail fin 200, thereby enhancing the adjustability of the underwater vehicle. In a specific embodiment, the drive unit 310 may be a drive motor.

[0047] See also Figure 2 In one embodiment of the present invention, the second drive mechanism 400 includes a drive member 410 and a cam 420 disposed on the drive member 410. The cam 420 is connected to the side of the connecting frame 321 facing away from the drive unit 310. The drive member 410 can drive the cam 420 to rotate, thereby driving the connecting frame 321 to move along the central axis of the output shaft of the drive unit 310. Specifically, the second drive mechanism 400 utilizes the cam 420 to drive the connecting frame 321 to move along the central axis of the output shaft of the drive unit 310. This has a simple structure and can reduce the manufacturing difficulty of the underwater vehicle. In one specific embodiment, the drive member 410 can be a steering gear. In this embodiment, the connection between the cam 420 and the connecting frame 321 can adopt the following structure: the cam 420 is provided with an annular block around its circumference, and the connecting frame 321 is provided with a groove, in which the annular block is slidably mounted.

[0048] See also Figure 3In another embodiment of the present invention, the transmission assembly 320 includes a connecting frame 321, a shaft 322 and a connecting block 324. The shaft 322 is rotatably set on the connecting frame 321. The output shaft of the driving unit 310 is slidably passed through the shaft 322 and engaged with the shaft 322. The connecting block 324 is set on the shaft 322. The first end of the swing arm 330 is hinged to the rotating shaft 210, and the second end of the swing arm 330 is slidably set on the connecting block 324. The sliding direction of the second end of the swing arm 330 is set at an angle to the central axis direction of the shaft 322. Specifically, the drive unit 310 can drive the shaft 322 to rotate, drive the connecting block 324 to rotate about the central axis of the shaft 322, and drive the swing arm 330 to rotate about the central axis of the shaft 322, causing the end of the swing arm 330 away from the rotating shaft 210 to perform circular motion in a vertical plane. This in turn drives the rotating shaft 210 to rotate back and forth, driving the bionic tail fin 200 to swing back and forth, providing the propulsion required for the underwater vehicle to move forward. In this embodiment, the output shaft of the drive unit 310 is engaged with and extends through the shaft 322. When the second drive mechanism 400 drives the shaft 322 to move along the central axis of the output shaft of the drive unit 310, the shaft 322 is always engaged with and slides relative to the output shaft of the drive unit 310. In a specific embodiment, the sliding direction of the second end of the swing arm 330 is perpendicular to the central axis of the shaft 322, and the output shaft of the drive unit 310 is coaxial with the shaft 322.

[0049] The second driving mechanism 400 is connected to the connecting frame 321 and can drive the connecting frame 321 to move along the central axis direction of the output shaft of the driving unit 310, and then drive the shaft 322 to move toward or away from the rotating shaft 210, so as to drive the second end of the swing arm 330 to slide on the connecting block 324 and adjust the angle between the swing arm 330 and the shaft 322. In this embodiment, the second drive mechanism 400 drives the connecting frame 321 to move along the central axis of the output shaft of the drive unit 310, thereby driving the shaft 322 rotatably mounted on the connecting frame 321 to move along the central axis of the output shaft of the drive unit 310 toward or away from the rotating shaft 210. This allows the distance between the shaft 322 and the rotating shaft 210 to be adjusted, allowing the second end of the swing arm 330 to slide on the connecting block 324, thereby adjusting the angle between the swing arm 330 and the shaft 322. This in turn adjusts the radius of the circular motion of the end of the swing arm 330 away from the rotating shaft 210 in a vertical plane, thereby adjusting the angle of the reciprocating rotation of the rotating shaft 210 and the swing amplitude of the bionic tail fin 200, thereby enhancing the adjustability of the underwater vehicle. In a specific embodiment, the drive unit 310 may be a drive motor.

[0050] See also Figure 3In another embodiment of the present invention, the second drive mechanism 400 includes a drive member 410 and a screw rod 430 disposed on the drive member 410, with the connecting frame 321 meshing with the screw rod 430. The drive member 410 can drive the screw rod 430 to rotate, thereby driving the connecting frame 321 to move along the central axis of the output shaft of the drive unit 310. In this embodiment, the second drive mechanism 400 utilizes the screw rod 430 to drive the connecting frame 321 along the central axis of the output shaft of the drive unit 310. This has a simple structure and can reduce the difficulty of manufacturing the underwater vehicle. In a specific embodiment, the drive member 410 can be a steering gear. It should be noted that in addition to the two methods described above, the connecting frame 321 can also be driven by a drive cylinder or a drive oil cylinder, and the movement of the connecting frame 321 can be guided by a slide rail and a slider.

[0051] See also Figure 3 In another embodiment of the present invention, the connecting block 324 is provided with a slot 3241, and the second end of the swing arm 330 is slidably disposed in the slot 3241. The slot 3241 extends at an angle to the central axis of the shaft 322. In this embodiment, by providing the slot 3241 on the connecting block 324 and placing the second end of the swing arm 330 within the slot 3241, sliding movement between the second end of the swing arm 330 and the connecting block 324 is achieved. This simplifies the structure of the underwater vehicle and reduces the difficulty of manufacturing the underwater vehicle. In a specific embodiment, the slot 3241 extends perpendicular to the central axis of the shaft 322. The two opposing sidewalls of the slot 3241 are both curved. A spherical block 331 is provided at the second end of the swing arm 330. The spherical block 331 is accommodated in the slot 3241, and both sidewalls of the slot 3241 are in contact with the spherical block 331. Specifically, the swing arm 330 realizes sliding between the second end of the swing arm 330 and the connecting block 324 through the spherical block 331 and the slide groove 3241 matching the spherical block 331. On the one hand, it can reduce the manufacturing difficulty of the underwater vehicle. On the other hand, it can reduce the resistance that needs to be overcome when the driving unit 310 drives the rotating shaft 210 to rotate back and forth, so that the swing of the bionic tail fin 200 is smoother.

[0052] See also Figure 1 and Figure 4In one embodiment of the present invention, the housing 100 further includes a head 120 and a main body 130 connecting the head 120 and the tail 110. The underwater vehicle also includes a bionic pectoral fin 500 and a third drive mechanism 600. The third drive mechanism 600 is disposed within the housing 100. The bionic pectoral fin 500 is rotatably mounted on the third drive mechanism 600 and extends out of the main body 130. The third drive mechanism 600 is used to drive the bionic pectoral fin 500 to swing about its rotation axis and to drive the end of the bionic pectoral fin 500 away from the main body 130 to rotate toward or away from the head 120. In this embodiment, the third drive mechanism 600 drives the bionic pectoral fin 500 to move, achieving a bionic flapping motion with two rotational degrees of freedom, thereby enhancing the underwater vehicle's maneuverability during underwater motion. Specifically, the third drive mechanism 600 can drive the bionic pectoral fin 500 to swing about its rotational axis, achieving pitch motion of the bionic pectoral fin 500, mimicking the up-and-down swinging of a fish's pectoral fin. Simultaneously, the third drive mechanism 600 can also drive the end of the bionic pectoral fin 500 away from the main body 130 toward or away from the head 120, achieving twisting motion of the bionic pectoral fin 500, mimicking the forward and backward swinging of a fish's pectoral fin. Furthermore, by integrating the motions of the bionic caudal fin 200 and the bionic pectoral fin 500, an adjustable amplitude swinging of the bionic caudal fin 200 and a two-degree-of-freedom flapping of the bionic pectoral fin 500 are achieved, enabling the underwater vehicle to achieve high-speed and highly maneuverable propulsion capabilities.

[0053] See also Figure 4 In one embodiment of the present invention, the third driving mechanism 600 includes a bracket 610, a first servo 620, a second servo 630, and a transmission member 640 provided on the bracket 610. The bionic pectoral fin 500 is rotatably provided on the transmission member 640. The first servo 620 drives the bionic pectoral fin 500 to rotate around the vertical direction of the transmission member 640 through the transmission member 640, so that the end of the bionic pectoral fin 500 away from the main body 130 rotates toward or away from the head 120. The second servo 630 drives the bionic pectoral fin 500 to swing around its rotation axis through the transmission member 640. Figure 4 As shown in Z in FIG, the rotation axis of the bionic pectoral fin 500 is as shown in FIG. Figure 4 In this embodiment, two servos are used to respectively drive the bionic pectoral fin 500 to swing around its rotation axis and to rotate around the vertical direction of the transmission member 640, thereby avoiding interference caused by the multi-directional rotation of the bionic pectoral fin 500 and ensuring the accuracy of the bionic pectoral fin 500 when performing bionic motion.

[0054] See also Figure 4In one embodiment of the present invention, the transmission member 640 includes a shell 641 and a bevel gear 642 arranged in the shell 641. One end of the bionic pectoral fin 500 is arranged in the shell 641 and meshes with the bevel gear 642. The bracket 610 is also provided with a first synchronous wheel 611, a second synchronous wheel 612, and a first shaft and a second shaft coaxially nested. The first shaft connects the first synchronous wheel 611 and the shell 641, and the second shaft is connected to the bevel gear 642; the first servo 620 drives the first shaft to rotate through the first synchronous belt and the first synchronous wheel 611, thereby driving the shell 641 to rotate around the vertical direction of the transmission member 640, thereby driving the bionic pectoral fin 500 to rotate around the vertical direction of the transmission member 640; the second servo 630 drives the second shaft to rotate through the second synchronous belt and the second synchronous wheel 612, thereby driving the bevel gear 642 to rotate, thereby driving the bionic pectoral fin 500 to swing around its rotation axis. The underwater vehicle utilizes a coaxial nested structural design and a coupling design of helical gears 642, and is driven by an independent servo. This allows the bionic pectoral fin 500 to rotate vertically about a transmission shaft and swing about its rotation axis, thereby mimicking the up-and-down and back-and-forth swinging motions of fish pectoral fins. This simplifies the structure of the underwater vehicle, reduces structural complexity, and makes the underwater vehicle more compact. Furthermore, it avoids interference caused by the multi-directional rotation of the bionic pectoral fin 500, ensuring the accuracy of the bionic pectoral fin 500 during bionic motion. In this embodiment, the two rotational degrees of freedom of the transmission member 640 are conjugate, and the rotation angles of the two servos are identical to the inclination angles of the bionic pectoral fin 500 along the two conjugate axes.

[0055] See also Figure 1 In this embodiment, the underwater vehicle further includes an oil sealing mechanism 700, which is disposed in the outer shell 100 and wrapped around the first driving mechanism 300, and can achieve the purpose of oil sealing and drag reduction; and, to ensure the normal operation of the underwater vehicle underwater, corresponding dynamic seals and static seals are provided at each connection of the outer shell 100 of the underwater vehicle.

[0056] See also Figure 5 , Figure 5 This is a schematic diagram of the various parameters in the calculation method provided by the present invention. The present invention also proposes a variable amplitude bionic propulsion design method, which is applied to the above-mentioned underwater vehicle. The variable amplitude bionic propulsion design method includes:

[0057] Obtain the angle between the output shaft of the driving unit 310 and the horizontal plane when rotating, the radius of the circle when the end of the swing arm 330 away from the rotating shaft 210 performs a circular motion in the vertical plane, and the projected length from the end of the swing arm 330 connected to the rotating shaft 210 to the other end of the swing arm 330 in the horizontal plane;

[0058] The swing angle of the bionic tail fin 200 is obtained according to a preset formula, and the preset formula is:

[0059]

[0060] Wherein, γ is the angle between the output shaft of the driving unit 310 and the horizontal direction when rotating, R is the radius of the circle when the end of the swing arm 330 away from the rotating shaft 210 performs a circular motion in the vertical plane, θ is the swing angle of the bionic tail fin 200, and d is the horizontal projection length from the end of the swing arm 330 connected to the rotating shaft 210 to the other end of the swing arm 330;

[0061] Specifically, by calculating the swing angle of the bionic tail fin 200 in real time, the swing state of the bionic tail fin 200 can be monitored in real time. Furthermore, the calculated swing angles of the bionic tail fin 200 are integrated into a data set. By selecting the maximum value in the data set, the maximum swing angle of the bionic tail fin 200 can be determined, and thus the swing amplitude of the bionic tail fin 200 can be determined.

[0062] Secondly, R and d in the above formula should also satisfy the following relationship:

[0063] R=dtanA

[0064] Wherein, A is the maximum value of the swing angle of the bionic tail fin 200 .

[0065] The above description is merely an exemplary embodiment of the present invention and does not limit the scope of protection of the present invention. Any equivalent structural transformation made by using the contents of the present invention description and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, is included in the scope of protection of the present invention.

Claims

1. An underwater vehicle, characterized in that: include: a housing having a tail portion; A bionic tail fin, the bionic tail fin being rotatably disposed on the tail via a rotating shaft; a first drive mechanism, the first drive mechanism being disposed within the housing and comprising a drive unit, a transmission assembly, and a swing arm connected in sequence, the swing arm being hinged to the rotating shaft and movably connected to the transmission assembly, the swing arm being arranged at an angle to the rotating shaft, and the drive unit being capable of driving the rotating shaft to reciprocate via the transmission assembly and the swing arm; A second driving mechanism is disposed in the housing and connected to the transmission assembly; the second driving mechanism can drive the transmission assembly to move toward or away from the rotating shaft to adjust the angle between the swing arm and the transmission assembly.

2. The underwater vehicle according to claim 1, wherein: The transmission assembly includes a connecting frame, a shaft and a connecting rod that are hinged to each other, the shaft being rotatably arranged on the connecting frame, the output shaft of the drive unit being slidably passed through the shaft and engaged with the shaft, the connecting rod being hinged to the swing arm, the connecting rod being arranged at an angle to the shaft and the swing arm; The second driving mechanism is connected to the connecting frame and can drive the connecting frame to move along the central axis of the output shaft of the driving unit, thereby driving the shaft to move toward or away from the rotating shaft to adjust the angle between the swing arm and the shaft.

3. The underwater vehicle according to claim 2, wherein: The second driving mechanism includes a driving member and a cam provided on the driving member, wherein the cam abuts against a side of the connecting frame facing away from the driving unit; The driving member can drive the cam to rotate, so as to drive the connecting frame to move along the central axis direction of the output shaft of the driving unit.

4. The underwater vehicle according to claim 1, wherein: The transmission assembly includes a connecting frame, a shaft and a connecting block, the shaft is rotatably arranged on the connecting frame, the output shaft of the driving unit is slidably passed through the shaft and engaged with the shaft, the connecting block is arranged on the shaft, the first end of the swing arm is hinged to the rotating shaft, the second end of the swing arm is slidably arranged on the connecting block, and the sliding direction of the second end of the swing arm is arranged at an angle to the central axis direction of the shaft; The second driving mechanism is connected to the connecting frame and can drive the connecting frame to move along the central axis direction of the output shaft of the driving unit, thereby driving the shaft to move toward or away from the rotating shaft, so as to drive the second end of the swing arm to slide on the connecting block and adjust the angle between the swing arm and the shaft.

5. The underwater vehicle according to claim 4, characterized in that: The second driving mechanism includes a driving member and a screw rod provided on the driving member, and the connecting frame is engaged with the screw rod; the driving member can drive the screw rod to rotate, so as to drive the connecting frame to move along the central axis direction of the output shaft of the driving unit.

6. The underwater vehicle according to claim 4, wherein: The connecting block is provided with a sliding groove, the second end of the swing arm is slidably arranged in the sliding groove, and the extending direction of the sliding groove is arranged at an angle to the central axis direction of the shaft.

7. The underwater vehicle according to claim 1, wherein: The shell also has a head and a main body connecting the head and the tail. The underwater vehicle also includes a bionic pectoral fin and a third driving mechanism. The third driving mechanism is arranged in the shell. The bionic pectoral fin is rotatably arranged on the third driving mechanism and extends out of the main body; the third driving mechanism is used to drive the bionic pectoral fin to swing around its rotation axis, and to drive the end of the bionic pectoral fin away from the main body to rotate toward or away from the head.

8. The underwater vehicle according to claim 7, wherein: The third driving mechanism includes a bracket, a first servo arranged on the bracket, a second servo and a transmission member, and the bionic pectoral fin is rotatably arranged on the transmission member; the first servo drives the bionic pectoral fin to rotate around the vertical direction of the transmission member through the transmission member, so that the bionic pectoral fin rotates away from one end of the main body toward or away from the head, and the second servo drives the bionic pectoral fin to swing around its rotation axis through the transmission member.

9. The underwater vehicle according to claim 8, wherein: The transmission member includes a housing and a helical gear disposed in the housing. One end of the bionic pectoral fin is disposed in the housing and meshes with the helical gear. The bracket is further provided with a first synchronous wheel, a second synchronous wheel, and a first shaft and a second shaft coaxially nested. The first shaft connects the first synchronous wheel and the housing, and the second shaft connects to the helical gear. The first servo drives the first shaft to rotate through the first synchronous belt and the first synchronous wheel, thereby driving the shell to rotate around the vertical direction of the transmission member to drive the bionic pectoral fin to rotate around the vertical direction of the transmission member; the second servo drives the second shaft to rotate through the second synchronous belt and the second synchronous wheel, thereby driving the bevel gear to rotate to drive the bionic pectoral fin to swing around its rotation axis.

10. A variable amplitude bionic propulsion design method, applied to the underwater vehicle according to any one of claims 1 to 9, characterized in that: The variable amplitude bionic propulsion design method comprises: Obtain the angle between the output shaft of the driving unit and the horizontal plane when it rotates, the radius of the circle when the end of the swing arm away from the rotating shaft performs a circular motion in the vertical plane, and the projected length from the end of the swing arm connected to the rotating shaft to the other end of the swing arm in the horizontal plane; The swing angle of the bionic tail fin is obtained according to a preset formula, which is: Among them, γ is the angle between the output shaft of the driving unit and the horizontal plane when it rotates, R is the radius of the circle when the end of the swing arm away from the rotating shaft makes a circular motion in the vertical plane, θ is the swing angle of the bionic tail fin, and d is the projected length from the end of the swing arm connected to the rotating shaft to the other end of the swing arm on the horizontal plane.

Images