High-propulsive-force underwater bionic robot with asymmetric-rigidity swimming arms

Abstract

The invention discloses a high-propulsive-force underwater bionic robot with asymmetrical-rigidity swimming arms. The high-propulsive-force underwater bionic robot comprises a flow guide cover, a waterproof cabin, the swimming arms and a swimming power device. The flow guide cover is fixedly connected with the waterproof cabin body, and water flow resistance is reduced by adopting a streamline external design; the waterproof cabin body comprises a base and a waterproof shell, the base and the waterproof cabin body are fixed through bolts and nuts, an O-shaped ring and silica gel are adopted for sealing and waterproofing, and the waterproof cabin body bears the buoyancy adjusting device, the gravity center adjusting device, the force storage power device, the load and the control panel. The four swimming arms are symmetrically installed at the bottom of the base and driven by the swimming power device to swing in a reciprocating mode. The force storage power device comprises a main power motor, a driving rotary disc, a driving check block, a screw bearing and a driven connecting rod, and the swimming power device and the swimming arms are driven to move through spring energy storage and kinetic energy release. Through the innovative mechanical structure and power design, the underwater stable and efficient movement performance is achieved, and meanwhile the excellent gravity center adjusting capacity and load capacity are achieved.

Description

Technical Field

[0001] The invention relates to the fields of bionics and mechanical structures, and in particular to a bionic jellyfish robot which can realize posture changes underwater and has high load capacity and efficient propulsion performance. Background Art

[0002] Bionic robots are a type of artificial intelligence device that imitates biological movement patterns and behavioral characteristics. They have broad application prospects in underwater detection, environmental monitoring, national defense and military, and entertainment industries. The swimming movement of jellyfish mainly includes two stages: relaxation (expansion) and contraction (propulsion). It generates thrust by quickly closing and reduces the resistance area by slowly opening to maintain a stable propulsion effect. In addition, the unique buoyancy regulation ability of jellyfish enables it to achieve highly flexible vertical movement in water. However, existing underwater bionic robots mostly imitate the movement of jellyfish, but still face many technical challenges in achieving these movements. For example, existing jellyfish bionic robots have the following problems: Limited center of gravity adjustment capability: Existing designs mostly use simple buoyancy adjustment mechanisms, but it is difficult to achieve precise center of gravity adjustment in complex underwater environments, resulting in relatively simple posture control of the robot, affecting the stability and flexibility of movement.

[0003] Slow movement speed: Although the propulsion systems of some existing jellyfish bionic robots imitate the contraction stage of jellyfish, the thrust output during the contraction stage is relatively linear, making it difficult to achieve rapid response, resulting in slow movement speed of the robot.

[0004] Weak load capacity: Many existing bionic jellyfish robots have relatively simple functional designs. Although they can perform basic movements, they are difficult to carry large loads due to the limitations of the power system and cannot adapt to complex underwater tasks.

[0005] Based on the above problems, the present invention proposes a bionic jellyfish robot, which achieves stable and efficient underwater motion performance through innovative mechanical structure and power design, and at the same time has excellent center of gravity adjustment ability and load capacity. Summary of the invention

[0006] The purpose of the present invention is to provide a high-propulsion underwater bionic robot with asymmetric stiffness swimming arms in view of the deficiencies in the prior art.

[0007] The technical solution adopted by the present invention to solve the technical problem is as follows: The present invention comprises a deflector (1), a waterproof cabin (2), a swimming arm (3) and a swimming power device (4).

[0008] The deflector (1) is fixedly connected to the waterproof cabin (2) and adopts a streamlined external design to reduce water flow resistance; the waterproof cabin (2) includes a base (21) and a waterproof shell (22); the base (21) and the waterproof cabin (22) are fixed by bolts and nuts, and are sealed and waterproof by O-rings and silicone, and carry a buoyancy adjustment device (5), a center of gravity adjustment device (6), a power storage device (7), a load and a control panel; the deflector (1) is provided with a plurality of through holes for water inlet. There are four swimming arms (3) symmetrically mounted on the bottom of the base (21) and driven by the swimming power device (4) to swing back and forth. The power storage device (7) includes a main power motor (71), a main turntable (72), a main stopper (73), a screw bearing (74), and a driven connecting rod (75). The swimming power device (4) and the swimming arm (3) are driven to move by storing and releasing kinetic energy through a spring (43).

[0009] The control panel is not the core description focus of the structure of the present invention.

[0010] Furthermore, the swimming arm (3) comprises: a waterproof steering gear (30), a main rigid frame first section (31), a main rigid frame last section (32), a left rigid frame first section (33), a left rigid frame last section (34), a right rigid frame first section (35), a right rigid frame last section (36), a flexible material film (37), a driving gear (38), and a driven gear (39). The main rigid frame first section (31) and the main rigid frame last section (32), the left rigid frame first section (33) and the left rigid frame last section (34), and the right rigid frame first section (35) and the right rigid frame last section (36) are respectively connected, that is, the first and last sections corresponding to each part of the rigid frame are hinged through stud bearings and can rotate freely.

[0011] Furthermore, the waterproof steering gear output shaft of the swimming arm (3) is fixed to the first section (35) of the right rigid frame, the protrusion on the first section (35) of the right rigid frame is connected to the driving gear (38), the driving gear (38) is meshed with the driven gear (39), and the driven gear (39) is fixed to the first section (33) of the left rigid frame; when the waterproof steering gear output shaft rotates, the driving gear (38) drives the driven gear (39) to rotate, so that the left rigid frame and the right rigid frame rotate synchronously in opposite directions, so that the swimming arm fan is opened and closed. The left rigid frame includes the first section (33) of the left rigid frame and the last section (34) of the left rigid frame, and the right rigid frame includes the first section (35) of the right rigid frame and the last section (36) of the right rigid frame. Furthermore, the main transmission rod (42) of the swimming power device (4) moves in the vertical direction, the rod end joint bearing (41) of the swimming power device (4) is fixedly connected to the main transmission rod (42) by a nut, the adjustable double-head bearing connecting rod (44) is hinged to the main transmission rod (42) by a stud and a bearing, the main transmission rod (42) passes through the hole in the center of the base (21) and moves up and down in the vertical direction, the spring is installed between the main transmission rod (42) and the base (21), and the spring (43) is installed between the main transmission rod (42) and the base (21) to provide an elastic driving force during the movement.

[0012] Furthermore, a silicone bellows is installed on the main transmission rod (42), one end of the bellows is fixed and sealed by a pipe clamp, one end is installed at the end of the main transmission rod (42), and one end is installed on the protrusion below the base (21), and the installation position is sealed with silicone. When the main transmission rod (42) moves up and down, the bellows moves together due to its good elasticity. The internal space of the bellows is connected to the inside of the waterproof cabin (2) and is a waterless area.

[0013] Furthermore, the active power motor (71) is fixed in the motor mounting groove provided on the base (21) through a bracket, the output shaft of the active power motor (71) is fixedly connected to the active block (73), the active block (73) is connected to the active turntable (72) through a needle bearing, and the two can rotate freely coaxially, and the screw bearing (74) is installed on the active turntable (72) and fixed by a nut. The active turntable (72), the driven connecting rod (75), and the rod end joint bearing (41) are hinged in sequence through the studs and bearings; when the active block (73) rotates, it drives the active turntable and the driven connecting rod (75), so that the main transmission rod (42) moves upward, and the compression spring (43) realizes energy storage. When the spring (43) is released, the swimming arm (3) is driven to paddle quickly through the main transmission rod (42).

[0014] Furthermore, the swimming arm (3) has an asymmetric stiffness design: a micro spring is connected between the first section and the last section of the rigid skeleton, which is used to adapt to the bending of the water flow to reduce resistance in the slow relaxation stage, and to restore to a straight state through the spring tension in the fast paddling stage; a limited position structure is also provided between the first section and the last section, which is used to abut against each other in the fast paddling stage, thereby maintaining the rigidity of the swimming arm (3) and ensuring propulsion efficiency. The rigid skeleton includes a main rigid skeleton, a left rigid skeleton and a right rigid skeleton; Furthermore, the center of gravity adjustment device (6) includes a counterweight (61), a gear motor (62), a rack (63), a guide rail (64), a counterweight frame (65), a guide rail slider (66) and a clamping strip (67), wherein the gear motor (62) drives the gear to move linearly along the rack (63), the counterweight (61), the gear motor (62) and the guide rail slider (66) are mounted on the counterweight frame (65) for adjusting the center of gravity of the robot, and the guide rail (64), the rack (63) and the clamping strip (67) are mounted on the base (21).

[0015] Furthermore, the robot's swimming motion is divided into three processes: a slow relaxation phase, a fast stroke phase, and a gliding phase. The robot's swimming arm (3) closes and bends in the slow relaxation phase to reduce resistance; opens and remains straight in the fast stroke phase to provide strong thrust; and remains stationary in the gliding phase to reduce resistance.

[0016] In the slow relaxation stage, the motor rotates to drive the active block (73) to rotate clockwise. When the active block (73) contacts the screw bearing (74), the screw bearing (74) and the active turntable (72) are driven to rotate together. Subsequently, the active block (73) continues to rotate, and while driving the active turntable (72) to rotate, the main transmission rod (42) is pulled upward through the driven connecting rod (75), the spring (43) is compressed, and the swimming arm (3) is driven to open gradually through the connecting rod, and the fan surface of the swimming arm (3) is closed and bent to reduce resistance.

[0017] The rapid paddling stage: when the active turntable (72) rotates to the highest point, the spring (43) is compressed to the limit, the swimming arm (3) reaches the maximum opening angle, and the swimming arm (3) opens in a fan shape. At this time, the screw bearing (74) is separated from the contact with the active turntable, and the elastic potential energy released by the spring (43) provides power to pull the main transmission rod (42) downward, driving the swimming arm (3) to maintain a straight state and shrink rapidly, completing the rapid paddling stage of swimming, which is the main work process of the robot swimming underwater. When the screw bearing (74) reaches the bottom, the rapid paddling stage ends.

[0018] The beneficial effects of the present invention are as follows: 1. The present invention provides power to compress the spring (43) through a motor, stores energy for the spring (43), and then releases the spring (43) to allow the spring (43) to quickly release the stored elastic potential energy, providing the swimming arm (3) with a relatively large instantaneous power. This working characteristic brings a relatively high instantaneous thrust to the robot, effectively improving the acceleration and rapid response capability of the robot. At the same time, based on the linear mechanical characteristics of the spring (43), the thrust distribution is optimized through the spring (43) power storage and release process, thereby improving energy utilization and propulsion efficiency.

[0019] 2. The asymmetric stiffness design of the swimming arm (3) of the present invention cooperates with the flexible film. When it is slowly relaxed, the fan surface closes and bends to reduce resistance. When it is quickly paddled, the fan surface opens and remains straight to increase thrust, effectively reducing the influence of the resistance of the swimming arm (3) on the speed of the robot.

[0020] 3. The robot of the present invention has a large load, with a total weight of 11 kg, a load of 1.1 kg on the center of gravity adjustment device, and can carry an additional load of 4.4 kg. The center of gravity adjustment device (6) can affect the overall center of gravity of the robot to the greatest extent, and perform precise horizontal-vertical posture control on the inclination of the robot.

[0021] In summary, the present invention solves the problems of low propulsion efficiency and weak load capacity of existing underwater bionic robots. The underwater robot can achieve stable and efficient motion performance and flexible posture control underwater. Its core technologies include an efficient swimming power device based on motor and spring energy storage drive, an asymmetric stiffness swimming arm and a large load center of gravity adjustment device, which significantly improves the propulsion efficiency, energy utilization and load capacity. The swimming arm combines a rigid skeleton with a flexible material film and uses a servo to achieve three motion states (active opening, active closing, and passive bending), which optimizes the flexibility and efficiency of the robot's movement. The power storage device drives the spring to store energy through a motor and releases elastic potential energy, providing instantaneous large thrust for the swimming arm, enhancing the robot's rapid response ability in water. In addition, the center of gravity adjustment device adjusts the center of gravity of the robot by accurately controlling the movement of the counterweight frame, further improving its posture control ability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0023] Figure 2 It is a schematic diagram of the external structure of the swimming arm (3) of the present invention.

[0024] Figure 3 It is a schematic diagram of the transmission structure of the swimming arm (3) of the present invention.

[0025] Figure 4 It is a schematic diagram of the bending structure of the swimming arm (3) of the present invention.

[0026] Figure 5 It is a schematic diagram of the center of gravity adjustment device (6) and the internal structure in the present invention.

[0027] Figure 6 It is a schematic diagram of the overall tilt of the center of gravity adjustment device of the present invention.

[0028] Figure 7 It is a schematic diagram of the distribution of the internal devices of the cabin in the present invention.

[0029] Figure 8It is a schematic structural diagram of a swimming power device (4) and a power storage power device (7) in the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0031] like Figure 1 As shown, the present invention provides a high-propulsion underwater bionic robot with asymmetric stiffness swimming arms, comprising a fairing (1), a waterproof cabin (2), a buoyancy adjustment device (5), a center of gravity adjustment device (6), a power storage device (7), a swimming power device (4) and a swimming arm (3). The robot can efficiently complete bionic motion, buoyancy and center of gravity adjustment, and flexible direction control. Its core technologies include a high-efficiency power storage system based on spring drive, a large-load center of gravity adjustment device with significant effect, and an asymmetric stiffness swimming arm design, which significantly improves propulsion efficiency and energy utilization.

[0032] The deflector (1) and the waterproof cabin (2) are installed together and adopt a streamlined design, which can effectively reduce water flow resistance. The waterproof cabin (2) is installed with a buoyancy adjustment device (5), a center of gravity adjustment device (6) and an electronic control module. The waterproof cabin (2) provides waterproof protection and load support. The center of gravity adjustment device (6) adopts a gear rack transmission as the core driving system, and the gear motor (62) drives the gear meshing with the rack (63) to rotate, thereby realizing the linear motion of the counterweight frame (65) along the guide rail (64). This transmission method has high rigidity and precision, and can maintain stable center of gravity adjustment under different working conditions. At the same time, the tight combination of the gear rack mechanism and the guide rail (64) is ensured by the clamping strip (67), thereby improving the stability of the structure. The counterweight frame (65) and the counterweight block (61) are fixed and installed on the guide rail slider (66), and the guide rail (64) provides movement constraints and guidance, ensuring that the counterweight frame (65) can still move smoothly when carrying a large load.

[0033] The power storage device (7) drives the connecting rod system through a motor to store energy for the spring (43) of the swimming power device (4), and the two together provide power for the swimming arm (3) to simulate the expansion and contraction movement of the jellyfish. The swimming drive arm is composed of a rigid frame and a flexible material film (37), and is combined with a steering gear to achieve switching between three movement states (active opening, active closing, and passive bending), thereby effectively improving propulsion efficiency and movement flexibility.

[0034] like Figure 1As shown, the deflector (1) and the waterproof shell (22) are formed by 3D printing of high-strength white resin. The two are fixedly installed together to form a streamlined external profile, which can effectively reduce water flow resistance. The space between the deflector (1) and the waterproof shell (22) is a water-immersed area, where a water-immersed counterweight is placed. The water-immersed counterweight is 1.8 kg and is designed as a replaceable module. The counterweight object should be symmetrical and its weight can be adjusted within the range of 1.5-2.0 kg to meet different load requirements. A plurality of regularly arranged drainage holes are attached to both sides of the deflector (1) to ensure that it is connected to the external water environment.

[0035] like Figure 2 As shown, each swimming arm (3) includes a waterproof steering gear (30), a main rigid frame, a left rigid frame, a right rigid frame, a flexible material film (37), a driving gear (38), and a driven gear (39). The main rigid frame includes a main rigid frame first section (31) and a main rigid frame last section (32); the left rigid frame includes a left rigid frame first section (33) and a left rigid frame last section (34); the right rigid frame includes a right rigid frame first section (35) and a right rigid frame last section (36). The frames are all formed by 3D printing of high-strength resin, and the first and last sections corresponding to each part of the rigid frame are hinged by stud bearings and can rotate freely.

[0036] The deflector (1) adopts a streamlined rotating body design and selects the Granville line type in the streamlined curve cluster normal line type. The whole is streamlined and has good fluid dynamics performance. This design can effectively reduce the resistance of water flow and improve the movement efficiency of the robot. The deflector (1) is provided with a plurality of drainage holes for water inlet and outlet, which are used to balance the water level inside and outside the deflector (1).

[0037] like Figure 3 As shown, the output shaft of the waterproof steering engine (30) is fixed to the driving gear (38) and the first section (35) of the right rigid frame, and the driven gear (39) is fixed to the first section (33) of the left rigid frame. When the output shaft of the waterproof steering engine (30) rotates, the main rigid frame does not move, and the driving gear (38) drives the driven gear (39) to rotate, so that the left rigid frame and the right rigid frame rotate synchronously in opposite directions, so that the fan surface of the swimming arm (3) is opened. At the same time, four synchronous connecting rods, two long and two short, are installed on the left and right frames of the swimming arm (3), which are hinged by bolts and bearings. The other end of the connecting rod is also installed on the micro guide rail slider (66) of the main frame by bolts and bearings. The rotation of the right rigid frame will drive the slider to move up and down on the guide rail (64), and synchronously drive the connecting rod on the other side and the driven frame to rotate, helping the fan surface to open and close synchronously better, thereby increasing the structural stability.

[0038] A flexible material film (37) is installed between the frames of the swimming arm (3) and is fixed on both sides by bolts and nuts. When the fan is closed, the film will be retracted and clamped between the frames, and will not increase the resistance of the swimming arm (3). When the fan is opened, the flexible material film (37) is opened and tightened, which can increase the resistance of the swimming arm (3).

[0039] like Figure 4 As shown, the swimming arm (3) has asymmetric stiffness, and a micro spring is connected between the first and last sections of the rigid skeleton of the swimming arm (3), and the two ends of the spring are fixed at Figure 4 When the swimming arm (3) accumulates power and slowly relaxes, the lower part of the swimming arm (3) bends under the action of water flow resistance to reduce the resistance received, and the spring is stretched at this time. When the power accumulation stage ends, the swimming arm (3) reaches the highest point, and the swimming arm (3) returns to a straight state under the action of the spring tension.

[0040] The swimming arm (3) needs greater rigidity when it contracts quickly to paddle, so a limited position structure is designed at the connection between the head and the end of the skeleton, such as Figure 4 As shown in the dotted circle on the right side of the middle, they can resist each other when subjected to force, so that the other side of the swimming arm (3) will not bend when subjected to force, and will remain in a straight state, ensuring that the swimming thrust will not be reduced.

[0041] The asymmetric stiffness design of the swimming arm (3) reduces water flow resistance by bending the lower part during the slow relaxation phase, thereby improving movement efficiency; while in the fast paddling phase, the rigidity is maintained by the limiting structure, ensuring sufficient propulsion force, significantly improving propulsion efficiency and stability, and is more in line with bionic movement characteristics than traditional designs.

[0042] like Figure 5 As shown, the gear of the gear motor (62) of the center of gravity adjustment device (6) meshes with the rack (63), and the driving force is provided by the rotation of the gear, and the directional constraint is provided by the guide rail slider (66) installed on the counterweight frame (65) moving on the guide rail (64). Because the load of the counterweight frame (65) is relatively large, in order to prevent the counterweight frame (65) from being deformed due to excessive load and affecting the meshing of the gear rack, the movement trajectory of the load frame is further limited by the clamping strip (67), ensuring the close connection between the gear and the rack (63) and improving the stability of the structure. The buffer block is set at the extreme position of the counterweight frame (65). When the counterweight frame (65) moves to the end of the stroke, it can effectively absorb kinetic energy to prevent the counterweight from impacting and damaging the base plate. As shown Figure 6 As shown, the center of gravity adjustment device is tilted 10° as a whole. This tilt design can significantly increase the adjustment range of the center of gravity, thereby making the center of gravity change more flexible and the adjustment effect of the device more significant.

[0043] like Figure 7As shown, a power storage device (7) is installed on the base (21), which includes a main power motor (71), a driving turntable (72), a driving block (73), a screw bearing (74), and a driven connecting rod (75). The main power motor (71) is fixed in a designed motor mounting groove on the base (21) through a bracket, and the output shaft of the main power motor (71) is fixedly connected to the driving block (73), and the driving block (73) is connected to the driving turntable (72) through a needle bearing, and the two can rotate freely coaxially, and the screw bearing (74) is installed on the driving turntable (72) and fixed by a nut. The driving turntable (72), the driven connecting rod (75), and the rod end joint bearing (41) are hinged in sequence through studs and bearings. The driving turntable (72) and the driven connecting rod (75) are formed by 3D printing of high-strength white resin, and the active block (73) is made of metal material due to the high working intensity required.

[0044] The base (21) is formed by 3D printing of high-strength and high-toughness black resin, and is fixed to the waterproof shell (22) by screws and nuts. The base (21) and the waterproof shell (22) are both provided with two circles of O-ring installation grooves for placing O-rings, and some silicone with a hardness of 10 degrees is added and tightened by bolts to ensure the sealing performance.

[0045] The base (21) is equipped with a depth sensor and a waterproof switch. When a problem occurs, the power can be cut off manually underwater to protect the robot. Two small holes are also opened to place the power line and signal line of the waterproof steering gear (30). The waterproof steering gear (30) is arranged in groups of two, and each group uses one hole. After the wires pass through, they are sealed with silicone to ensure waterproof performance, and a layer of hot melt adhesive is covered on both surfaces of the silicone to increase strength.

[0046] A limit base is installed below the base (21) to provide an end limit for the swimming arm (3) to ensure that the swimming arm (3) will not over-contract inwards due to inertia at the end of the rapid contraction stage, causing the swimming arms (3) to interfere with and collide with each other. Four swimming arms (3) are symmetrically installed at the bottom of the base (21), and are hinged by bearings and copper columns, so that the swimming arms (3) can rotate freely.

[0047] In order to reduce friction, a planar thrust needle roller bearing and a gasket are installed between the active rotating disk (72) and the driven connecting rod (75), which can also play a role in adjusting the flatness.

[0048] The buoyancy device (5) uses a screw motor as a power source to drive the sealing piston to reciprocate through the flange and the connecting rod. Through this design, the buoyancy device can realize the operation of pumping and draining water, thereby adjusting the buoyancy of the robot; like Figure 8As shown, the rod end joint bearing (41) of the swimming power device (4) is fixedly connected to the main transmission rod (42) through a nut, the adjustable double-headed bearing connecting rod (44) is hinged to the main transmission rod (42) through a stud and a bearing, the main transmission rod (42) passes through the hole in the center of the base (21) and moves up and down in the vertical direction, and the spring (43) is installed between the main transmission rod (42) and the base (21).

[0049] The adjustable double-headed bearing connecting rod (44) is composed of a positive-threaded rod end bearing, a negative-threaded rod end bearing and a threaded rod. The overall length of the double-headed bearing connecting rod (44) can be changed by rotating the threaded rod to adjust the working stroke range of the swimming arm (3).

[0050] A silicone bellows is installed on the main transmission rod (42), one end of the bellows is fixed and sealed by a pipe clamp, one end is installed at the end of the main transmission rod (42), and one end is installed on the protrusion below the base (21), and the installation position is sealed with silicone. When the main transmission rod (42) moves up and down, the bellows moves together due to its good elasticity. The internal space of the bellows is connected to the inside of the waterproof cabin (2) and is a waterless area.

[0051] The robot's swimming motion is divided into three processes: slow relaxation phase, fast paddling phase and gliding phase.

[0052] In the slow relaxation stage, the power storage device (7) works, and the active power motor (71) drives the active block (73) to rotate clockwise. When the active block (73) contacts the screw bearing (74), the screw bearing (74) and the active turntable (72) are pushed to rotate together. Subsequently, the active block (73) continues to rotate, and while driving the active turntable (72) to rotate, the main transmission rod (42) is pulled upward through the driven connecting rod (75), the spring is compressed, and the swimming arm (3) is driven to gradually open through the adjustable double-headed bearing connecting rod (44).

[0053] Based on the linear mechanical properties of the spring (43), the stage where the spring (43) has a larger elastic force coincides with the stage where the projected area of ​​the swimming arm (3) is the largest during the paddling process, while the stage where the spring (43) has a smaller elastic force coincides with the stage where the projected area of ​​the swimming arm (3) is the smallest during the paddling process. Overall, this increases the proportion of useful work, thereby improving swimming efficiency and energy utilization.

[0054] The rapid paddling stage begins when the active turntable (72) rotates to the highest point, at which time the spring (43) is compressed to the limit and the swimming arm (3) reaches the maximum opening angle. The screw bearing (74) is separated from the contact with the active turntable, and the elastic potential energy released by the spring (43) provides power to pull the main transmission rod (42) downward, driving the swimming arm (3) to quickly contract, completing the rapid paddling stage of swimming, which is the main work process of the robot swimming underwater. When the screw bearing (74) reaches the bottom, the rapid paddling stage ends.

[0055] Subsequently, the robot enters the gliding phase, and the system enters a standby state, waiting for the active block (73) driven by the motor to complete the remaining half-circle of rotation, after which the swimming main power device returns to the initial state and prepares to enter the next action cycle.

[0056] When turning is required, the fan of the swimming arm (3) on the side close to the turning direction is always kept in a closed state, reducing the propulsion force, so that the propulsion force on this side is reduced, and a rotation torque is generated. After the robot completes the turning, the swimming arm (3) resumes normal operation and moves forward in the new direction.

[0057] The robot body is controlled by a single-chip microcomputer model STM32f407ZGT6, which controls the motor power supply through a relay, serves as a power-off protection unit in the event of an operating failure, and controls the robot's total power supply through a waterproof switch. The wireless serial port module (ATK-LORA), gyroscope (MPU6050) and depth sensor are integrated, and the wireless serial port module communicates wirelessly with the host computer, realizing remote real-time control of the robot's direction, depth and propulsion through wireless communication.

[0058] Experimental data: The bionic jellyfish robot weighs about 11kg, with a total weight of 5.5kg. The maximum diameter of the cabin is 240mm, the waterproof cabin (2) is 270mm high, the cabin with the deflector (1) is 400mm long, and the total length of the robot is 740mm. It is independently powered by a 24V lithium battery with a capacity of 6000mAh, without external signal cables and power cables. The test site is a small pool with a length of 4 meters and a width of 2 meters, and a water depth of 1 meter. During the test, the robot's sliding time is set to 1 second, and a complete movement cycle is about 2.3 seconds. The opening process of the swimming arm (3) is about 0.8 seconds. The speed at this stage is slow, with an average speed of 10cm / s. The paddling process of the swimming arm (3) is about 0.5 seconds, and the sliding process is 1 second. The average speed at this stage is 25-30cm / s. The average overall speed is about 20-23cm / s.

Claims

1. A high-propulsion underwater bionic robot with asymmetric stiffness swimming arms, the characteristics of which include: A fairing (1), a waterproof cabin (2), a swimming arm (3) and a swimming power device (4); The deflector (1) is fixedly connected to the waterproof cabin (2) and adopts a streamlined external design to reduce water flow resistance; the waterproof cabin (2) comprises a base (21) and a waterproof outer shell (22); the base (21) and the waterproof cabin (22) are fixed by bolts and nuts, and are sealed and waterproofed by O-rings and silicone, and carry a buoyancy adjustment device (5), a center of gravity adjustment device (6), a power storage device (7), a load and a control panel; There are four swimming arms (3) in total, which are symmetrically mounted on the bottom of the base (21) and driven by the swimming power device (4) to swing back and forth; The power storage device (7) comprises a main power motor (71), a main rotating disk (72), a main stopper (73), a screw bearing (74), and a driven connecting rod (75); and the swimming power device (4) and the swimming arm (3) are driven to move by storing energy and releasing kinetic energy through a spring (43).

2. The high propulsion underwater bionic robot with asymmetric stiffness swimming arms according to claim 1, characterized in that: The swimming arm (3) comprises: a waterproof steering gear (30), a main rigid frame first section (31), a main rigid frame last section (32), a left rigid frame first section (33), a left rigid frame last section (34), a right rigid frame first section (35), a right rigid frame last section (36), a flexible material film (37), a driving gear (38), and a driven gear (39); the main rigid frame first section (31) and the main rigid frame last section (32), the left rigid frame first section (33) and the left rigid frame last section (34), and the right rigid frame first section (35) and the right rigid frame last section (36) are respectively connected, that is, the first and last sections corresponding to each part of the rigid frame are hinged through a stud bearing and can rotate freely.

3. The high propulsion underwater bionic robot with asymmetric stiffness swimming arms according to claim 2, characterized in that: The waterproof steering gear output shaft of the swimming arm (3) is fixed to the right rigid frame first section (35), the protrusion on the right rigid frame first section (35) is connected to the driving gear (38), the driving gear (38) is meshed with the driven gear (39), and the driven gear (39) is fixed to the left rigid frame first section (33); when the waterproof steering gear output shaft rotates, the driving gear (38) drives the driven gear (39) to rotate, so that the left rigid frame and the right rigid frame rotate synchronously in opposite directions, so that the swimming arm fan surface opens and closes; the left rigid frame includes the left rigid frame first section (33) and the left rigid frame last section (34), and the right rigid frame includes the right rigid frame first section (35) and the right rigid frame last section (36).

4. The high propulsion underwater bionic robot with asymmetric stiffness swimming arms according to claim 1, characterized in that: The main transmission rod (42) of the swimming power device (4) moves in the vertical direction, the rod end joint bearing (41) of the swimming power device (4) is fixedly connected to the main transmission rod (42) through a nut, the adjustable double-head bearing connecting rod (44) is hinged to the main transmission rod (42) through a stud and a bearing, the main transmission rod (42) passes through a hole in the center of the base (21) and moves up and down in the vertical direction, a spring is installed between the main transmission rod (42) and the base (21), and a spring (43) is installed between the main transmission rod (42) and the base (21) to provide an elastic driving force during the movement.

5. The high propulsion underwater bionic robot with asymmetric stiffness swimming arms according to claim 4, characterized in that: A silicone bellows is installed on the main transmission rod (42), one end of the bellows is fixed and sealed by a pipe clamp and installed at the end of the main transmission rod (42), and the other end is installed on the protrusion below the base (21), and the installation position is sealed with silicone; when the main transmission rod (42) moves up and down, the bellows moves together due to its good elasticity; the internal space of the bellows is connected to the inside of the waterproof cabin (2) and is a waterless area.

6. The high propulsion underwater bionic robot with asymmetric stiffness swimming arms according to claim 1 or 5, characterized in that: The active power motor (71) is fixed in a motor mounting groove designed on the base (21) through a bracket, the output shaft of the active power motor (71) is fixedly connected to the active block (73), the active block (73) is connected to the active turntable (72) through a needle bearing, and the two can rotate freely coaxially, the screw bearing (74) is installed on the active turntable (72) and fixed by a nut; the active turntable (72), the driven connecting rod (75), and the rod end joint bearing (41) are hinged in sequence through studs and bearings; when the active block (73) rotates, it drives the active turntable and the driven connecting rod (75), so that the main transmission rod (42) moves upward, the compression spring (43) realizes energy storage, and when the spring (43) is released, the swimming arm (3) is driven to paddle quickly through the main transmission rod (42).

7. The high propulsion underwater bionic robot with asymmetric stiffness swimming arms according to claim 1, characterized in that: The swimming arm (3) has an asymmetric stiffness design: a micro spring is connected between the first section and the last section of its rigid skeleton, which is used to close and bend the fan-shaped surface in the slow relaxation stage to reduce resistance, and to restore the fan-shaped surface to open and maintain a straight state through the spring tension in the fast paddling stage to provide a strong thrust; a limiting structure is also provided between the first section and the last section, which are used to abut against each other in the fast paddling stage, thereby maintaining the rigidity of the swimming arm (3).

8. The high propulsion underwater bionic robot with asymmetric stiffness swimming arms according to claim 1, characterized in that: The center of gravity adjustment device (6) comprises a counterweight (61), a gear motor (62), a rack (63), a guide rail (64), a counterweight frame (65), a guide rail slider (66) and a clamping strip (67). The gear motor (62) drives the gear to move linearly along the rack (63). The counterweight (61), the gear motor (62) and the guide rail slider (66) are mounted on the counterweight frame (65) to adjust the center of gravity of the robot. The guide rail (64), the rack (63) and the clamping strip (67) are mounted on a base (21).

9. The high propulsion underwater bionic robot with asymmetric stiffness swimming arms according to claim 7, characterized in that: In the slow relaxation stage, the motor rotates to drive the active block (73) to rotate clockwise. When the active block (73) contacts the screw bearing (74), the screw bearing (74) and the active turntable (72) are pushed to rotate together. Subsequently, the active block (73) continues to rotate, and while driving the active turntable (72) to rotate, the main transmission rod (42) is pulled upward through the driven connecting rod (75), the spring (43) is compressed, and the swimming arm (3) is driven to open gradually through the connecting rod, and the fan surface of the swimming arm (3) is closed and bent, thereby reducing resistance.

10. The high propulsion underwater bionic robot with asymmetric stiffness swimming arms according to claim 7, characterized in that: The rapid paddling stage: when the active turntable (72) rotates to the highest point, the spring (43) is compressed to the limit, the swimming arm (3) reaches the maximum opening angle, and the swimming arm (3) opens in a fan shape; at this time, the screw bearing (74) is separated from the contact with the active turntable, and the elastic potential energy released by the spring (43) provides power to pull the main transmission rod (42) downward, driving the swimming arm (3) to maintain a straight state and shrink rapidly, completing the rapid paddling stage of swimming, which is the main work process of the robot swimming underwater; when the screw bearing (74) reaches the bottom, the rapid paddling stage ends.

Images