Sea simulation robot capable of realizing two tail movement modes

Abstract

The invention discloses a seal-imitating robot with two tail movement modes, and belongs to the technical field of underwater navigation equipment. The robot comprises a front body assembly, a rear drive assembly and a flexible outer skin. The front body assembly comprises a head, a control cabin and a seal-imitating front fin, and the rear drive assembly is connected with the rear part of the front body and is formed by sequentially connecting a seal-imitating lumbar vertebra unit, a pelvis unit, a lower limb bone unit and a tail fin unit. The lumbar vertebra unit comprises a bionic segment structure and a lumbar vertebra driving device, wherein the bionic segment structure swings through bending. The lower limb bone unit comprises tibia arranged on the two sides of the pelvis and a tibia driving device for driving the tibia to swing on the same side; the tail fin unit is composed of a fin root bone, tail toes and a tail fin driving device, the multiple tail toes form a fan-shaped support, and the tail fin driving device controls opening and closing of the fan-shaped support and swinging of the fin root bone. The seal imitating robot is compact in design structure, has efficient, smooth and stable motion characteristics and good environmental adaptability, and has excellent maneuverability and continuous operation capacity in various underwater tasks.

Description

Technical Field

[0001] The invention belongs to the technical field of underwater navigation equipment, and in particular relates to a seal-like robot capable of realizing two tail movement modes. Background Art

[0002] Traditional underwater vehicles mainly rely on controlling their own buoyancy and the position change of the center of gravity to achieve basic functions such as floating, diving and turning, and provide forward propulsion through propellers and other propulsion devices, so they have a high propulsion speed. However, due to the rigid mechanical structure, this type of vehicle has shortcomings in adapting to complex marine environments. For example, although the traditional propeller propulsion device can generate a large propulsion force, it is also accompanied by a large noise, which not only affects the concealment of the vehicle, but may also interfere with the normal activities of marine organisms, thereby limiting its application in sensitive tasks such as marine monitoring and ecological protection.

[0003] In recent years, bionic underwater robots, as a frontier direction of underwater robot research, have begun to attract widespread attention. Research in this field aims to combine traditional mechanical structures with the movement characteristics of marine organisms to design robots that are closer to natural organisms, making them soft, flexible, low-noise, and have strong concealment and environmental adaptability. By imitating the movement mechanism of marine organisms, bionic underwater robots can integrate into the marine environment more naturally, and are particularly suitable for performing tasks that require high concealment, such as detection and cruising. Among many bionic objects, seals are favored by researchers for their excellent maneuverability and propulsion efficiency. As a pinniped mammal, seals generate propulsion through the regular swing of their tails, and have high swimming efficiency and fluid dynamic performance. At the same time, seals can maintain the balance and stability of their bodies by adjusting the movement of the tail fins on both sides of the tail, so that they can show flexible and steady movement characteristics in various complex waters. This coordinated and sensitive tail movement provides important reference value for bionic design, and is expected to give bionic underwater robots better maneuverability and environmental adaptability, so that they can show low noise, concealment and high efficiency in noise-sensitive underwater environments.

[0004] At present, seal bionic design is still in the initial exploration stage in the field of underwater robots. Existing research has not yet achieved a high degree of simulation of seal drive mode, exposing multiple technical deficiencies and limitations. First, there is a large gap in the degree of freedom and coordination of the joint movements of the bionic seal, and it is impossible to achieve the fine control effect of the real seal. The tail joint of the seal is highly flexible, and smooth and effective propulsion is achieved by fine-tuning the bending and swinging of each joint. However, the current bionic design mostly adopts a simplified joint motion mode, lacking a true simulation of the natural movement of the seal. In addition, the bionic seal performs poorly in terms of movement smoothness. Real seals can show extremely high flexibility when moving in water, and their drive structure can be dynamically adjusted under different water flow environments, thereby achieving stable propulsion and precise steering. However, existing bionic designs are usually limited by rigid structures or single transmission mechanisms, resulting in stiff movements of bionic seals, lack of natural and smooth motion curves, and difficulty in adapting to complex underwater environments. Furthermore, in the transmission design of the drive structure, the bionic seal faces significant challenges. Seals rely on flexible muscle tissue for driving, while bionic seals generally use traditional mechanical transmission structures such as motors and gears. These rigid components have limitations in imitating the streamlined movement of organisms, often resulting in stiff and uncoordinated driving movements. At the same time, mechanical transmission devices also lead to increased noise and excessive energy consumption, reducing the concealment and endurance of bionic robots. Finally, the existing bionic designs need to be improved in terms of environmental adaptability. The unique driving method of seals enables them to swim flexibly in environments with turbulent water or full of obstacles, but the movement modes of existing bionic robots are mostly single forward propulsion, which makes it difficult to adapt to the ever-changing underwater environment, resulting in insufficient maneuverability. In general, the current bionic seal design has not achieved ideal results in terms of joint movement, flexibility, transmission structure and environmental adaptability. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a seal-like robot that can realize two tail movement modes, which solves the problems of insufficient freedom and coordination of joint movements, poor movement smoothness, rigid transmission structure, high energy consumption and noise, and poor environmental adaptability.

[0006] The present invention is implemented as follows: a seal-like robot capable of realizing two tail movement modes, characterized in that it includes a front body assembly, a rear drive assembly and a flexible outer skin arranged on the exterior; the front body assembly includes a head, a control cabin and a seal-like front fin installed on the control cabin, the rear drive assembly is connected to the rear of the front body assembly, and the rear drive assembly includes a seal-like lumbar unit, a seal-like pelvic unit, a femur-tibia-fibula unit and a seal-like tail fin unit connected in sequence from front to back; the seal-like lumbar unit includes a bionic segment structure that realizes swinging by bending and a lumbar drive device that drives the seal-like lumbar unit to swing, the femur-tibia-fibula unit includes tibias arranged on both sides of the seal-like pelvic unit and a tibia drive device that drives the two tibias to swing to the same side, the seal-like tail fin unit includes a fin root bone, a tail toe and a tail fin drive device, N of the tail toes form a fan-shaped surface support, and the tail fin drive device drives the fan-shaped surface support to open and close and the fin root bone to swing.

[0007] In the above technical solution, preferably, the seal-like tail fin unit includes a clamp, a tail fin connecting rod, a driving sliding pin, a tail fin pull rod, a tail fin driving rod, a driving slider, and a crank connecting rod; the tail toe includes a middle tail toe and an inner tail toe and an outer tail toe symmetrically located on both sides of the middle tail toe, the inner tail toe and the outer tail toe are installed on the clamp through a rotating shaft, and the middle tail toe is fixed to the clamp; the inner tail toe is installed with a sliding pin that slides along the inner tail toe, and the middle tail toe and the outer tail toe are provided with a fixed pin, the middle tail toe and the inner tail toe are connected with the inner tail toe and the inner tail toe and the outer tail toe are connected with the tail fin connecting rod, and the two ends of the tail fin connecting rod are respectively The tail fin driving device is connected to the driving pin and the fixed pin respectively; the driving pin is installed on the middle tail toe and moves along the length direction of the middle tail toe, the middle tail toe is connected to the inner tail toe through the tail fin pull rod, one end of the tail fin pull rod is connected to the driving pin, and the other end of the tail fin pull rod is connected to the inner tail toe through a pin; the driving slider is installed on the fin root bone in a linear movement manner, the output shaft of the tail fin driving device is connected to the driving slider through a crank connecting rod, the tail fin driving device drives the driving slider to move and drives the fin root bone to swing through the driving slider, and the driving slider and the driving pin are connected through the tail fin driving rod.

[0008] In the above technical solution, preferably, the rear end of the middle tail toe extends toward the rear of the splint to form the fin root bone, the rear end of the fin root bone is provided with a tail fin swing axis, and the tail fin driving device drives the fin root bone to swing with the tail fin swing axis as the axis; the front part of the middle tail toe is provided with a slide groove and the driving sliding pin is equipped through this slide groove, the fin root bone is provided with a slide groove and the driving slider is equipped through this slide groove; the inner tail toe is provided with a slide groove and the sliding pin shaft is installed through this slide groove.

[0009] In the above technical solution, preferably, the bionic segment structure includes segment vertebrae connected axially in sequence, two adjacent segment vertebrae are connected by a vertebral pin to form a bionic segment structure that can bend to the left and right sides, the segment vertebrae are connected in series with axial elastic cylindrical rods, and the elastic cylindrical rods apply elastic force to the bionic segment structure to restore it to an axial state, and the lumbar drive device is connected to the rear end of the seal-like lumbar unit through a pull wire and drives the bionic segment structure to bend through tension.

[0010] In the above technical solution, preferably, the segmental vertebra includes a cone, a cone bone and a skin support bone, the cones of adjacent segmental vertebrae are connected by a vertebral pin, the cone bone is fixed to the cone and forms a radial support, and the skin support bone is arranged on the periphery of the cone bone and forms an annular structure supporting the flexible outer skin.

[0011] In the above technical solution, preferably, the seal-like pelvic unit includes a front end plate and a rear end plate, the segmental vertebra is arranged between the front end plate and the rear end plate, the cone bone of the segmental vertebra is a disc-shaped structure, the elastic cylindrical rod is symmetrically arranged on the upper and lower sides of the serially connected cones and penetrates and connects the cone bone, the front end of the elastic cylindrical rod is connected to the front end plate, the rear end of the rear end plate is connected to the rear end plate, and the pull wire penetrates the vertebra of the segmental vertebra and is connected to the rear end plate.

[0012] In the above technical solution, preferably, the cone bone of the segmental vertebra is installed with a guide pulley, and the pull wire is guided through the guide pulley of the segmental vertebra in sequence and connected to the rear end plate.

[0013] In the above technical solution, preferably, a lumbar drive bracket is installed at the front part of the front end plate, an axially extending tensioning slide rail is installed on the lumbar drive bracket, a lumbar drive slide seat moving along the tensioning slide rail and an adjustment bolt for fixing the fixed position of the lumbar drive slide seat are installed on the tensioning slide rail, the lumbar drive device is installed on the lumbar drive slide seat, and the output shaft of the lumbar drive device is connected to the pull wire.

[0014] In the above technical solution, preferably, the femoral-tibia-fibula unit includes a lower limb support fixed to the pelvic unit, the root of the tibia is connected to the lower limb support through a first lower limb connecting rod, the rear part of the tibia is connected to the lower limb support through a second lower limb connecting rod, the output shaft of the tibial drive device is installed with a lower limb driving crank, and the second lower limb connecting rod is connected to the lower limb driving crank through a third lower limb connecting rod.

[0015] In the above technical solution, preferably, the second lower limb connecting rod, the third lower limb connecting rod, the lower limb driving crank, and the lower limb support form a parallelogram mechanism.

[0016] The present invention proposes a seal-like robot that can realize two tail motion modes. Through in-depth research on the skeletal structure and joint characteristics of the seal's tail, the tail motion unit structure of the seal-like underwater robot is mapped out, which enables it to have multiple superior performances. First of all, the robot's tail motion unit adopts a design with a simple structure and a short transmission chain, which greatly reduces the complexity of the motion structure, thereby reducing the difficulty of control and maintenance, and improving the reliability and adaptability of the overall device. Its tail motion can highly imitate the smooth movement of the seal's tail, making the robot move more naturally in the water and close to the streamlined motion mode of marine life. This flexibility ensures the smoothness and accuracy of the robot when performing operations such as turning and stabilizing the fuselage, and significantly improves the ability to adapt to the environment.

[0017] The tail motion unit of the seal-like robot uses four servos to achieve two tail fin swinging modes: one is the propulsion mode with the tail fin swinging in the same direction, and the other is the stability mode with the tail fin swinging in opposite directions. The same-direction swinging mode of the tail fin generates stable propulsion, allowing the robot to maintain stable and efficient motion performance when moving forward; the opposite-direction swinging mode of the tail fin provides excellent stability, helping the robot maintain the balance of the fuselage, making it more anti-interference in complex water flow environments. This dual-mode design can switch freely in different underwater environments, meeting the robot's needs for both speed and stability, and is the key to achieving high flexibility.

[0018] In addition, the present invention further optimizes the reliability and efficiency of movement in the design of the seal-like lumbar unit, especially by adopting a segmented skin and guide pulley structure. This design significantly reduces the friction between the internal structure and the external skin, as well as the friction between the steel wire and the internal structure, thereby avoiding energy loss and mechanism wear caused by friction resistance, and ensuring that the robot can maintain long-term efficient operation at low energy consumption. At the same time, a tensioning device is provided to effectively pre-tighten the steel wire to ensure that the transmission chain always maintains appropriate tension, which not only extends the service life of the transmission device, but also improves the accuracy and efficiency of mechanical transmission. In summary, the seal-like robot has a compact design structure, efficient, flexible, stable motion characteristics and good environmental adaptability, and can provide excellent maneuverability and lasting operational performance in a variety of underwater tasks.

[0019] In addition to the above advantages, this design can further improve the performance and application potential of the seal-like robot:

[0020] The seal-like robot adopts a smooth tail fin movement and a simplified transmission chain design, avoiding the strong noise caused by the high-speed rotation of traditional propellers in the water. This low-noise feature makes the robot more concealed in the underwater environment, especially suitable for underwater detection, ecological protection and military reconnaissance tasks, which can significantly reduce interference with marine life and improve concealment.

[0021] Since the design reduces complex transmission chains and redundant mechanical parts, the energy consumption required by the robot to perform movements is reduced. At the same time, the segmented skin and guide pulley structure further reduce friction and improve the overall transmission efficiency. It can reduce power consumption while maintaining high-performance movement, thereby extending the endurance time. This is especially important for long-term underwater cruising missions and helps improve the robot's ability to continue working.

[0022] The tail motion unit and lumbar unit of this design are modular, which is convenient for maintenance and replacement. The modular design not only improves the independence and flexibility of each component of the robot, but also provides a convenient operating space for subsequent performance upgrades and function expansions, making it easy to carry out corresponding modifications or upgrades according to different task requirements.

[0023] Since the four servos can be controlled independently, the robot can achieve more precise attitude adjustment and motion control. By finely adjusting the angle and speed of each servo, complex tail fin motion patterns can be achieved, thereby improving the robot's precise control capabilities in movements such as turning, acceleration and deceleration. This feature enables the robot to flexibly respond to complex dynamic environments when performing tasks in water, further improving mission efficiency.

[0024] Based on this bionic design, in the future, the robot can be combined with machine learning algorithms to adjust and optimize the movement mode of the tail fin in real time to adapt to different water flows and environments. By collecting and analyzing movement data in a variety of environments, the robot can gradually optimize its movement mode, further improve stability, energy efficiency and operational flexibility, and move towards intelligence.

[0025] In summary, this seal-like robot not only has a high degree of simplicity and flexibility in structural design, but also exhibits many advantages in low noise, energy saving, impact resistance, modularity, fine control and adaptive learning, giving it broad application prospects in application fields such as underwater detection, ecological monitoring, scientific research and covert operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the present invention;

[0027] Figure 2 It is a schematic diagram of the flexible outer skin segmentation of the present invention;

[0028] Figure 3 It is a schematic diagram of the internal structure of the present invention;

[0029] Figure 4 It is a schematic diagram of the internal structure of the seal-like lumbar vertebrae unit of the present invention;

[0030] Figure 5It is a wire drawing and winding diagram of the seal-like lumbar unit steel wire of the present invention;

[0031] Figure 6 is a schematic diagram of the internal structure of a vertebral unit of the present invention;

[0032] Figure 7 It is a schematic diagram of the internal structure of the femur-tibia-fibula unit of the present invention;

[0033] Figure 8 It is a schematic diagram of the internal structure of the seal-like pelvic unit of the present invention;

[0034] Fig. 9 It is a schematic diagram of the internal structure of the seal-like right tail fin of the present invention;

[0035] Fig.10 It is a top view of the seal-like left tail fin of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0037] In order to solve the problems of insufficient freedom and coordination of joint movements, poor movement flexibility, rigid transmission structure, high energy consumption and noise, and poor environmental adaptability, the present invention provides a seal-like robot that can realize two tail movement modes. The seal-like robot has a compact design structure, high efficiency, flexibility, and stable movement characteristics, and good environmental adaptability, and can provide excellent maneuverability and lasting operating performance in a variety of underwater tasks. In order to further illustrate the structure of the present invention, the detailed description is as follows in conjunction with the accompanying drawings:

[0038] See also Figure 1 , Figure 2 and Figure 3 , a seal-like robot capable of realizing two tail motion modes, including a front body assembly, a rear drive assembly and a flexible outer skin arranged on the surface. The front body assembly is the non-powered front part of the seal-like underwater vehicle, and the front body assembly includes a head 1, a control cabin 2 and a seal-like front fin 3 installed in the control cabin. The flexible outer skin is wrapped around the outside of the seal-like robot, so that the robot obtains a good hydrodynamic shape during movement. The rear drive assembly is connected to the rear of the front body assembly, and the rear drive assembly includes a seal-like lumbar unit 4, a seal-like pelvic unit 5, a femur-tibia-fibula unit 6 and a seal-like tail fin unit 7 connected in sequence from front to back. The seal-like front fin, the femur-tibia-fibula unit and the seal-like tail fin unit are symmetrically distributed on both sides of the robot. Here and in the following, "front, back, left and right" are all referenced to the direction of travel of the device.

[0039] Specifically, the head is a rigid head, and the conical structure is made by 3D printing. It has a good hydrodynamic shape and can reduce water resistance. The end of the head is connected to the front end of the control cabin by a countersunk bolt. The control cabin has a shape similar to a cylindrical rotating body. The power supply, control panel and other devices are placed inside to control the swinging movement of the seal-like lumbar unit, the femur-tibia-fibula unit and the seal-like tail fin unit. The end of the control cabin is connected to the lumbar unit drive cabin of the cylindrical rotating body set at the front end of the seal-like lumbar unit. The seal-like front fin has the same profile as the seal front fin. It is connected to the side of the control cabin by bolts. It has the function of assisting the robot to maintain a balanced state during the movement process and enhancing the stability of the movement.

[0040] like Figure 4 , Figure 5 and Figure 6 The seal-like lumbar unit includes a bionic segment structure that realizes swinging by bending and a lumbar drive device that drives the seal-like lumbar unit to swing. The bionic segment structure includes segment vertebrae that are connected axially in sequence, two adjacent segment vertebrae are connected by vertebral pins to form a bionic segment structure that can bend to the left and right sides, the segment vertebrae are connected in series with axial elastic cylindrical rods, and the elastic cylindrical rods apply elastic force to the bionic segment structure to restore it to an axial state, and the lumbar drive device is connected to the rear end of the seal-like lumbar unit by a pull line and drives the bionic segment structure to bend by tension. The segment vertebrae include a cone, a cone bone, a skin support bone, a front end plate, a rear end plate and a guide pulley. The cones of adjacent segment vertebrae are connected by vertebral pins, the cone bone is fixed to the cone and forms a radial support, and the skin support bone is arranged on the periphery of the cone bone and forms an annular structure that supports the flexible outer skin. The segmental vertebrae are arranged between the front end plate and the rear end plate. The cone bones of the segmental vertebrae are disc-shaped. The elastic cylindrical rods are symmetrically arranged on the upper and lower sides of the connected cones and penetrate and connect the cone bones. The front end of the elastic cylindrical rods is connected to the front end plate, and the rear end of the rear end plate is connected to the rear end plate. The pull wire penetrates the vertebrae of the segmental vertebrae and is connected to the rear end plate. The pull wire is guided through the guide pulleys of the segmental vertebrae in turn and connected to the rear end plate. The lumbar vertebrae are divided into segments. The internal skeleton and the skin of each stage are made into one piece, and the segments do not contact each other during movement. Compared with the internal skeleton covered with a skin as a whole, the friction is reduced. The design of the guide pulley will also reduce the friction of the steel wire pull wire during movement and improve efficiency.

[0041] The front part of the front end plate is equipped with a lumbar vertebra drive bracket, which is equipped with an axially extending tensioning rail, on which a lumbar vertebra drive slide seat moving along the tensioning rail and an adjusting bolt for fixing the fixed position of the lumbar vertebra drive slide seat are installed, and a lumbar vertebra drive device is installed on the lumbar vertebra drive slide seat, and the output shaft of the lumbar vertebra drive device is connected to the cable. The cable tensioning device in the lumbar unit ensures that the cable can be tensioned after being fixed to avoid the lumbar unit motor from generating idle stroke.

[0042] Specifically, the seal-like lumbar unit is the first motion joint of the device. The lumbar unit drive cabin 4-1 is located at the front of the part and is connected to the end of the control cabin by countersunk bolts. The shape of the lumbar unit drive cabin is a cylindrical rotating body shape, and its exterior is wrapped with a flexible skin. The interior of the lumbar unit drive cabin is used to place the lumbar drive device for controlling the swing of the seal-like lumbar unit and the tensioning assembly composed of the lumbar drive bracket and the tensioning slide rail. The lumbar drive device is the first servo 4-2. The lumbar unit drive cabin is connected to the front end plate by bolts. The lumbar drive bracket 4-3 is connected to the front mounting plate by bolts. The tensioning slide rail 4-4 is installed on the lumbar drive bracket. The lumbar drive slide 4-5 is mounted on the tensioning slide rail and the two form an axial linear motion pair. The first servo is installed on the lumbar drive slide, so that the first servo and its components can move relative to the tensioning slide rail. The driving mode of the seal-like lumbar vertebra unit is wire-drawing drive. In this embodiment, the wire is a steel wire 4-6. The end of the steel wire is fixed on the wire drum 4-7 on the output shaft of the first steering gear and is led out from both ends after being wound for multiple turns. The steel wire passes through the front end plate 4-8 and is successively wound on the guide pulleys of the segmental vertebrae of the seal-like lumbar vertebra unit, and is fixed on the wire-drawing hole of the rear end plate 4-15 after being led out from the last guide pulley. The adjusting bolt 4-9 is threadedly connected to the lumbar vertebra drive bracket. After the steel wire is installed, the first steering gear can be moved forward relative to the tensioning slide rail by adjusting the bolt, so that the steel wire is in a tensioned state. The main body of the seal-like lumbar vertebra unit is composed of four segmental vertebrae connected together. Each segmental vertebra includes a cone 4-10, a cone bone 4-11, a skin support bone 4-12, a guide pulley 4-13 and an elastic cylindrical rod 4-14. The cone is connected by a pin to achieve the connection between the segmental vertebrae. The connection between the vertebrae and the skin support bone is bolted. Elastic cylindrical rods are arranged on the upper and lower sides of the seal-like lumbar vertebrae unit, and the two ends thereof are respectively inserted into the cylindrical grooves on the front plate and the rear plate. The two elastic cylindrical rods penetrate the vertebrae of each segment.

[0043] The swinging principle of the entire seal-like lumbar vertebrae unit is that when the first servo drives the wire drum to rotate, the length of the steel wire pull wire at both ends of the seal-like lumbar vertebrae unit changes, causing the seal-like lumbar vertebrae unit to generate a deflection torque, which will drive the elastic cylindrical rod to continuously deform, and then drive the rotation of each segment vertebrae unit to form a bending deflection in the overall axial direction, completing the swinging action in sequence.

[0044] The flexible skin on the outside of the seal-like lumbar vertebrae unit is segmented, and each segment of the flexible skin is directly connected to the skin support bone. The shapes of adjacent segments of the flexible skin are concentric arcs with different radii. This design can ensure that the segmented flexible skins will not contact each other when the vertebral units of the seal-like lumbar vertebrae unit move relative to each other, thereby reducing the friction during the movement of this part of the structure and improving the mechanical efficiency.

[0045] like Figure 7, the seal-like pelvic unit. The seal-like pelvic unit 5 is composed of an upper arc plate 5-1 and a lower arc plate 5-2 fixed to the rear end plate. The rear end plate is provided with a mounting hole, which is used to connect with the femur-tibia-fibula unit. The upper arc plate and the lower arc plate are connected to the rear end plate by bolts. The upper and lower arc plates enable the seal-like pelvic unit to maintain a good hydrodynamic shape, and at the same time, the driving part of the seal-like femur-tibia-fibula unit is accommodated inside.

[0046] like Figure 8 The femur-tibia-fibula unit 6 includes tibiae 6-1 arranged on both sides of the seal-like pelvic unit and a tibia driving device driving the two tibiae to swing to the same side. The femur-tibia-fibula unit includes a lower limb support, the root of the tibia is connected to the lower limb support through a first lower limb connecting rod, the rear of the tibia is connected to the lower limb support through a second lower limb connecting rod, the output shaft of the tibia driving device is installed with a lower limb driving crank, and the second lower limb connecting rod is connected to the lower limb driving crank through a third lower limb connecting rod. The second lower limb connecting rod, the third lower limb connecting rod, the lower limb driving crank, and the lower limb support form a parallelogram mechanism.

[0047] Specifically, the femur-tibia-fibula unit is the second motion unit of the device, and two planar six-bar mechanisms are connected in parallel to form its motion mechanism, and are symmetrically distributed on both sides of the seal-like pelvic unit. Specifically, the tibia on both sides is installed on the lower limb support through a connecting rod mechanism. In this embodiment, the lower limb support is the rear end plate of the seal-like lumbar vertebrae. Taking the tibia on the right side as an example, the first lower limb connecting rod 6-2, the tibia, the second lower limb connecting rod 6-3, the third lower limb connecting rod 6-4, the lower limb driving crank 6-5 and the rear end plate constitute the right side planar six-bar mechanism. The two ends of the first lower limb connecting rod, the second lower limb connecting rod, and the third lower limb connecting rod are all hinged to the corresponding parts through a pin shaft to form a flat connecting rod structure. The rear end plate is used as the frame part of the two planar six-bar mechanisms on the left and right sides. By designing the length of each rod, the second lower limb connecting rod, the third lower limb connecting rod, the lower limb driving crank, and the lower limb support form a parallelogram mechanism. The angle of the lower limb driving cranks on the left and right sides is fixed. In this embodiment, the lower limb driving cranks of the connecting rod mechanisms on the left and right sides are the same rocker arm components. When the lower limb driving cranks swing, the tibias on both sides act synchronously and can move to opposite extreme positions. The tibia steering gear bracket is connected to the rear end plate by bolts. The tibia driving device is a second steering gear 6-6, which is fixed on the tibia steering gear bracket. The output shaft of the second steering gear drives the rocker arm component to swing, thereby driving the tibias on both sides of the femur-tibia-fibula unit to move. A bilaterally symmetrical Z-shaped bracket 6-7 is also provided to install and support the second lower limb connecting rods on the left and right sides. The moving components are formed into a revolute pair through bolts, nuts and sleeves. The moving components except the tibias on both sides are built into the shell space formed by the upper arc plate and the lower arc plate of the seal-like pelvic unit. The mechanism maps the femur and tibia and fibula of a real seal, and the movement angles of the components corresponding to the femur and tibia and fibula during the mechanism design are also corresponding to the rotation limit angles of the biological anatomical bones, which is conducive to realizing movement similar to that of a real seal.

[0048] The seal-like tail fin unit is the third motion unit of this robot, consisting of a left tail fin and a right tail fin. The left and right tail fins are symmetrically distributed on the left and right sides of the robot's tail, and form a revolute pair with the left and right tibias of the femur-tibia-fibula unit respectively. Since the two tail fins have the same composition structure, the right tail fin of the seal-like tail fin unit is taken as an example to describe its composition and motion principle.

[0049] Taking the right tail fin as an example, Fig. 9 and Fig.10 , including a fin root bone 7-1, a tail toe and a tail fin driving device, N tail toes form a fan-shaped surface support, and the tail fin driving device drives the fan-shaped surface support to open and close and the fin root bone to swing. In this embodiment, the seal-like tail fin unit includes a clamping plate 7-2, a tail fin connecting rod 7-3, a driving sliding pin 7-4, a tail fin pull rod 7-5, a tail fin driving rod 7-6, a driving slider 7-7, and a crank connecting rod 7-8.

[0050] The tail toe includes a middle tail toe 7-9 and an inner tail toe 7-10 and an outer tail toe 7-11 symmetrically located on both sides of the middle tail toe. The inner tail toe and the outer tail toe are installed on the splint through a pin, and the middle tail toe is fixed to the splint; the inner tail toe is installed with a sliding pin 7-12 that slides along the inner tail toe, and the middle tail toe and the outer tail toe are provided with a fixed pin 7-13. The middle tail toe and the inner tail toe are connected as well as the inner tail toe and the outer tail toe are connected through a tail fin connecting rod, and the two ends of the tail fin connecting rod are respectively connected with the sliding pin and the fixed pin; the driving sliding pin is installed on the middle tail toe and moves along the length direction of the middle tail toe, and the middle tail toe and the inner tail toe are connected through a tail fin pull rod, one end of the tail fin pull rod is connected to the driving sliding pin, and the other end of the tail fin pull rod is connected to the inner tail toe through a pin. The driving slider is installed on the fin root bone in a linearly movable manner. The output shaft of the tail fin driving device is connected to the driving slider through a crank connecting rod. The tail fin driving device drives the slider to move and drives the fin root bone to swing through the driving slider. The driving slider and the driving slide pin are connected through the tail fin driving rod. Further, the rear end of the middle tail toe extends to the rear of the splint to form a fin root bone. The rear end of the fin root bone is provided with a tail fin swing shaft. The tail fin driving device drives the fin root bone to swing with the tail fin swing shaft as the axis. A slide groove is provided at the front of the middle tail toe and the driving slide pin is equipped through the slide groove. The fin root bone is provided with a slide groove and the driving slider is equipped through the slide groove. The inner tail toe is provided with a slide groove and the sliding pin shaft is installed through the slide groove.

[0051] The right tail fin of the above structure can realize periodic swinging accompanied by the opening and closing action of the fin surface, and the five tail toes and the splint constitute the main structure of the tail fin. The middle tail toe is fixed to the splint by a countersunk bolt, and the two outer tail toes, the two inner tail toes and the splint form a revolute pair, that is, these four tail toes can swing around the pin connected to the splint. The fin root bone forms a revolute pair with the tail fin bracket through bolts, nuts and sleeves, that is, the front end of the middle tail toe extends and is hinged with the tail fin bracket through a vertical tail fin swing axis. The tail fin drive device is the third steering gear 7-14 and is fixed to the tail fin bracket. The tail fin bracket can be a structural part of the tibia or an independent bracket fixed to the tibia. The output shaft of the third steering gear is connected to the crank connecting rod, which is the steering gear swing arm. The crank connecting rod is connected to the driving slider in a revolute pair, and the driving slider is arranged in the slide groove at the end of the middle tail toe. The crank connecting rod, the middle tail toe, the driving slider and the tail fin bracket constitute a swing guide rod mechanism. The third servo drives the crank connecting rod to rotate, thereby driving the middle tail toe and the entire seal-like right tail fin to swing. The middle tail toe and the inner tail toe are provided with sliding grooves along the length direction, and the driving sliding pin and the sliding pin shaft are respectively placed therein. One end of the tail fin connecting rod forms a rotating pair with the sliding pin shaft, and the other end of the tail fin connecting rod forms a rotating pair with the outer tail toe and the middle tail toe through the fixed pin shaft. The inner end of the tail fin pull rod on both sides of the middle tail toe forms a rotating pair with the driving sliding pin, and the outer end forms a rotating pair with the inner tail toe through the pin shaft. A long connecting rod passes through the driving sliding pin and the driving slider, which is the tail fin driving rod. The two ends of the tail fin driving rod are respectively welded to the driving sliding pin and the driving slider into a whole, which is called the slider connecting rod. The swing of the crank connecting rod drives the slider connecting rod to move inside the middle tail toe, thereby driving the movement of the driving sliding pin, the sliding pin shaft and the rotation of each connecting rod to realize the opening and closing action of the tail fin surface. A new bionic mechanism is designed for the single tail fin in the tail fin unit, which uses a motor to realize the movement in two vertical planes: swinging and opening and closing, which corresponds to the movement of the tail fin of a real seal. The tail fin can realize two modes: same-direction swinging and object swinging, which also corresponds to the movement of a real seal. The previous version of the seal robot patent could not realize the movement mode of the tail fins on both sides swinging in opposite directions. The robot can be turned by controlling the deflection of the lumbar unit, the deflection of the femur-tibia-fibula unit (lower limb unit), and the deflection of the unilateral tail fin (the other side of the tail fin does not swing, and the fin surface is closed to the minimum state).

[0052] The specific operation mode of this embodiment

[0053] The bionic prototype of the present invention is a harp seal, in which the lumbar vertebrae, lower limb bones and tail fin can be regarded as three motion joints respectively, and it has two tail motion modes. The first tail motion mode is to generate thrust by periodic swinging of the lumbar vertebrae, lower limb bones and tail fin, and this process is accompanied by the opening and closing movement of the tail fin. This is the most important tail motion mode of the seal. In this tail motion mode, the lower limb bones on both sides and the tail fin alternately complete the actions of the power stage and the recovery stage. Since the two lower limb bones and the tail fin move symmetrically in the power stage and the recovery stage, the seal's movement in half a motion cycle is described in detail.

[0054] The movement of the tibia and tail fin on both sides. At the beginning of the power stage, the lumbar spine and the lower limb bones are in the right extreme position, the right tail fin is approximately parallel to the seal's body axis and is in a closed state. At this time, the left lower limb is also in the right extreme position, and the left tail fin is approximately coincident with the seal's body axis and is in an open state. At the next moment, the lumbar spine and the right tibia swing to the left, the right tail fin quickly opens and dorsiflexes, forming a certain angle with the right tibia, the left tibia swings to the left, the left tail fin is adducted and gradually closed, when the lumbar spine and the lower limb bones are in the left extreme position, the right tail fin is approximately coincident with the seal's body axis and is in an open state, and the left tail fin is parallel to the seal's body axis and is in a closed state. At this point, the power stage of the right tibia and the right tail fin is completed, and the next moment will enter the recovery stage, while the left tibia and the left tail fin will enter the power stage. When the tibia and tail fins on both sides alternately complete the power stage and the recovery stage, the seal's movement in one cycle ends.

[0055] In the second tail movement mode, the lumbar spine and the tibia on both sides remain stationary, and the seal movement is the two tail fins swinging in opposite directions. In the power phase, the two tail fins swing outward at the same time and gradually open; in the recovery phase, the two tail fins swing inward at the same time and gradually close.

[0056] The seal-like robot designed by the present invention can realize two tail motion modes and can highly restore the seal tail motion mode. In the process of realizing the first tail motion mode, the description starts from the initial position of the device.

[0057] When the first steering gear rotates counterclockwise at a certain angle, part of the steel wire pull wire on the right side is wound on the wire drum, and part of the steel wire pull wire on the left side is released from the wire drum. The steel wire pull wires on both sides act on the rear end plate to form a rotation torque, and the elastic cylindrical rod running through the cone bone bends and deforms to the right. The deformation of the elastic cylindrical rod drives the segmental vertebra to swing to the right limit position. The second steering gear rotates counterclockwise at a certain angle, and the steering gear swing arm drives the moving components of the double-plane hexagonal mechanism of the femur-tibia-fibula unit to swing to the right, so that the lower limb bone part reaches the right limit position. The third servo in the right tail fin of the imitation seal tail fin rotates clockwise by a certain angle, so that the right tail fin of the imitation seal tail fin is approximately parallel to the axis of the seal body and is in a closed state. The third servo in the left tail fin of the imitation seal tail fin rotates clockwise by a certain angle, so that the left tail fin is approximately coincident with the axis of the seal body and is in an open state. At this time, the right tibia and the right tail fin of the device are in the initial positions of the power stage, and the left tibia and the left tail fin are in the initial positions of the recovery stage. The four driving servos make each unit of the device reach the extreme position at the same time according to the appropriate frequency.

[0058] In the next stage, the first steering gear rotates clockwise, the left part of the steel wire pull wire is wound on the wire drum, and the right part of the steel wire pull wire is released from the wire drum. The elastic cylindrical rod running through the cone bone bends and deforms to the left, and the deformation of the elastic cylindrical rod drives the segmental vertebra to swing to the left extreme position. The second steering gear rotates clockwise at a certain angle, and the steering gear swing arm drives the moving components of the double-plane hexagonal mechanism to swing to the left, so that the limb bone part reaches the left extreme position. The third steering gear of the right tail fin of the tail fin part rotates counterclockwise at a certain angle, and the right tail fin quickly opens and dorsiflexes to form a certain angle with the right tibia. The third steering gear of the left tail fin of the tail fin part rotates counterclockwise, and the left tail fin is adducted and gradually closed. At the end of the power stage, the right tail fin is approximately coincident with the seal body axis and is in an open state, and the left tail fin is parallel to the seal body axis and is in a closed state. At this point, the power stage of the right tibia and the right tail fin is completed, and the next moment will enter the recovery stage action, while the left tibia and the left tail fin will enter the power stage. When the tibiae and the caudal fins on both sides complete the power stage and the recovery stage alternately, the movement of the device in one cycle is completed.

[0059] During the implementation of the second tail motion mode, only the seal tail fin unit is imitated for movement. When the third servo controlling the right tail fin rotates counterclockwise and the third servo controlling the left tail fin rotates clockwise, the left and right tail fins swing outward and gradually open at the same time. This is the recovery stage of the second tail motion mode. When the third servo controlling the right tail fin rotates clockwise and the third servo controlling the left tail fin rotates counterclockwise, the left and right tail fins swing inward and gradually close at the same time. This is the power stage of the second tail motion mode.

[0060] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A seal-like robot capable of realizing two tail motion modes, characterized in that: It includes a front body assembly, a rear drive assembly and a flexible outer skin arranged on the exterior; the front body assembly includes a head, a control cabin and a seal-like front fin installed on the control cabin, the rear drive assembly is connected to the rear of the front body assembly, and the rear drive assembly includes a seal-like lumbar unit, a seal-like pelvic unit, a femur-tibia-fibula unit and a seal-like tail fin unit connected in sequence from front to back; the seal-like lumbar unit includes a bionic segment structure that realizes swinging by bending and a lumbar drive device that drives the seal-like lumbar unit to swing, the femur-tibia-fibula unit includes tibias arranged on both sides of the seal-like pelvic unit and a tibia drive device that drives the two tibias to swing to the same side, the seal-like tail fin unit includes a fin root bone, a tail toe and a tail fin drive device, N of the tail toes form a fan-shaped surface support, and the tail fin drive device drives the fan-shaped surface support to open and close and the fin root bone to swing.

2. The seal-like machine capable of realizing two tail motion modes according to claim 1, characterized in that: The seal-like tail fin unit comprises a splint, a tail fin connecting rod, a driving sliding pin, a tail fin pulling rod, a tail fin driving rod, a driving slider, and a crank connecting rod; the tail toe comprises a middle tail toe and an inner tail toe and an outer tail toe symmetrically located on both sides of the middle tail toe, the inner tail toe and the outer tail toe are installed on the splint through a rotating shaft, and the middle tail toe is fixed to the splint; the inner tail toe is installed with a sliding pin that slides along the inner tail toe, and the middle tail toe and the outer tail toe are provided with a fixed pin, the middle tail toe and the inner tail toe are connected to the inner tail toe and the inner tail toe and the outer tail toe are connected through the tail fin connecting rod, and the two ends of the tail fin connecting rod are respectively connected to the sliding pin The tail fin driving device is provided with a movable pin shaft and a fixed pin shaft; the driving sliding pin is installed on the middle tail toe and moves along the length direction of the middle tail toe, the middle tail toe is connected to the inner tail toe through the tail fin pull rod, one end of the tail fin pull rod is connected to the driving sliding pin, and the other end of the tail fin pull rod is connected to the inner tail toe through a pin shaft; the driving slider is installed on the fin root bone in a linear movement manner, the output shaft of the tail fin driving device is connected to the driving slider through a crank connecting rod, the tail fin driving device drives the driving slider to move and drives the fin root bone to swing through the driving slider, and the driving slider and the driving sliding pin are connected through the tail fin driving rod.

3. The seal-like machine capable of realizing two tail motion modes according to claim 2, characterized in that: The rear end of the middle tail toe extends toward the rear of the splint to form the fin root bone, and the rear end of the fin root bone is provided with a tail fin swing shaft, and the tail fin driving device drives the fin root bone to swing with the tail fin swing shaft as the axis; the front part of the middle tail toe is provided with a slide groove and the driving sliding pin is equipped through this slide groove, the fin root bone is provided with a slide groove and the driving slider is equipped through this slide groove; the inner tail toe is provided with a slide groove and the sliding pin shaft is installed through this slide groove.

4. The seal-like machine capable of realizing two tail motion modes according to claim 1, characterized in that: The bionic segment structure includes segment vertebrae that are axially connected in sequence, and two adjacent segment vertebrae are connected by vertebral pins to form a bionic segment structure that can bend to the left and right sides. The segment vertebrae are connected in series with axial elastic cylindrical rods, and the elastic cylindrical rods apply elastic force to the bionic segment structure to restore it to an axial state. The lumbar drive device is connected to the rear end of the seal-like lumbar unit through a pull wire and drives the bionic segment structure to bend through tension.

5. The seal-like machine capable of realizing two tail motion modes according to claim 4, characterized in that: The segmental vertebra includes a cone, a cone bone and a skin support bone. The cones of adjacent segmental vertebrae are connected by a vertebral pin. The cone bone is fixed to the cone and forms a radial support. The skin support bone is arranged on the periphery of the cone bone and forms an annular structure supporting the flexible outer skin.

6. The seal-like machine capable of realizing two tail motion modes according to claim 5, characterized in that: The seal-like pelvic unit includes a front end plate and a rear end plate, the segmental vertebra is arranged between the front end plate and the rear end plate, the cone bone of the segmental vertebra is a disc-shaped structure, the elastic cylindrical rod is symmetrically arranged on the upper and lower sides of the series of cones and penetrates and connects the cone bone, the front end of the elastic cylindrical rod is connected to the front end plate, the rear end of the rear end plate is connected to the rear end plate, and the pull wire penetrates the vertebra of the segmental vertebra and is connected to the rear end plate.

7. The seal-like machine capable of realizing two tail motion modes according to claim 6, characterized in that: The cone bone of the segmental vertebra is provided with a guide pulley, and the pull wire is guided through the guide pulley of the segmental vertebra in sequence and connected with the rear end plate.

8. The seal-like machine capable of realizing two tail motion modes according to claim 7, characterized in that: A lumbar vertebrae drive bracket is installed at the front of the front end plate, and an axially extending tensioning slide rail is installed on the lumbar vertebrae drive bracket. A lumbar vertebrae drive slide seat that moves along the tensioning slide rail and an adjustment bolt for fixing the position of the lumbar vertebrae drive slide seat are installed on the tensioning slide rail. The lumbar vertebrae drive device is installed on the lumbar vertebrae drive slide seat, and the output shaft of the lumbar vertebrae drive device is connected to the pull wire.

9. The seal-like machine capable of realizing two tail motion modes according to claim 1, characterized in that: The femoral-tibia-fibula unit includes a lower limb support fixed to the pelvic unit, the root of the tibia is connected to the lower limb support through a first lower limb connecting rod, the rear of the tibia is connected to the lower limb support through a second lower limb connecting rod, the output shaft of the tibial drive device is installed with a lower limb driving crank, and the second lower limb connecting rod is connected to the lower limb driving crank through a third lower limb connecting rod.

10. The seal-like machine capable of realizing two tail motion modes according to claim 9, characterized in that: The second lower limb connecting rod, the third lower limb connecting rod, the lower limb driving crank and the lower limb support form a parallelogram mechanism.

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