An underwater autonomous vehicle for seabed fixed-point sampling

Abstract

The present invention discloses an underwater autonomous vehicle for seabed fixed-point sampling, which includes an underwater robot body and a sampling device mounted on the underwater robot body. The sampling device includes a sampling arm and a sampling cylinder fixed on the underwater robot body, and a telescopic sampling head arranged at the free rotating end of the sampling arm for extracting liquid samples. A hose for transporting liquid samples is provided between the telescopic sampling head and the sampling cylinder. The underwater autonomous vehicle provided by the present invention is equipped with a highly flexible sampling manipulator to cope with the real and complex sampling tasks at seabed hydrothermal vents.

Description

Technical Field

[0001] The present invention belongs to the field of subsea sampling equipment, and particularly relates to an underwater autonomous vehicle for fixed-point sampling on the seabed. Background Art

[0002] Subsea hydrothermal fluid ejected from subsea hydrothermal vents is a high-temperature liquid formed by the interaction of seawater with rocks heated by magma. Hydrothermal plumes contain a large amount of heavy metals and reducing chemical substances, such as hydrogen sulfide, methane, Mn2+ ions, and Fe2+ ions. These heavy metals precipitate in the form of sulfides, sulfates, carbonates, and oxide minerals, forming subsea black smokers. It is estimated that the rare metals in these subsea hydrothermal deposits can be used as a mineral resource for industrial activities. Deep-sea hydrothermal activities also give birth to a unique hydrothermal ecosystem, and the chemical reactions in the hydrothermal fluid can provide the energy required for life for chemoautotrophic microorganisms around the hydrothermal vents. From the perspective of the dependence of the metabolism of hydrothermal vent microorganisms on hydrothermal activities, studying the composition of hydrothermal fluids is the key to understanding the life mechanism of microorganisms in hydrothermal areas.

[0003] As a kind of deep-sea exploration technology, sampling detection technology has brought back valuable samples such as minerals, microorganisms, and water quality in the ocean, providing important help for exploring ocean resources and promoting biological and ecological research. Achieving stable sampling operations in the deep-sea environment with high salinity, high pressure, and poor visibility is an important problem to be solved in seabed research. The seabed geomorphic features are intricate, and the diameters of hydrothermal vents range from 3 cm to dozens of centimeters. Sampling equipment is required to perform fixed-point sampling to ensure the success rate of sampling. Otherwise, the disturbance generated by ocean currents and the like will not only damage the terrain and harm the equipment, resulting in sampling failure, but also threaten the safety of operators if manned submersibles are relied on for sampling.

[0004] Patent document CN113834693A discloses an enrichment device for useful elements in hydrothermal vent fluids, including an inhalation faucet, an inhalation telescopic pipe assembly, a switching valve, an input pipe, an output pipe, a discharge telescopic pipe assembly, a working cabin protective housing, and a gravity sedimentation chamber, a centrifugal sedimentation chamber, a fine filtration chamber, a fluid chamber, a cation adsorption chamber, an anion adsorption chamber, and a deep water pump that are sequentially connected from the inlet to the outlet and installed inside the working cabin protective housing. The inhalation telescopic pipe assembly and the discharge telescopic pipe assembly are respectively rotatably installed at the inlet end and the outlet end of the working cabin protective housing. The inlet end of the inhalation telescopic pipe assembly is connected to the inhalation faucet with the suction port facing downward, the outlet end is connected to the gravity sedimentation chamber through the input pipe, one end of the output pipe is connected to the deep water pump, and the other end is connected to the discharge telescopic pipe assembly. A switching valve is installed on the inhalation telescopic pipe assembly. This device fails to consider the shape of subsea hydrothermal vents and the collection environment, and the fixed-shaped inhalation telescopic pipe cannot be well adapted to the complex subsea environment.

[0005] Patent document CN101975682A discloses a subsea hydrothermal fluid automatic sampler. The sampler includes a valve-opening cavity fixed on a bracket, a sampling cavity, a temperature measurement circuit cavity, and a temperature display circuit cavity. The sampler of the present invention uses an electronically controlled trigger mechanism in the valve-opening cavity to control the sampling valve to achieve automatic sampling. The sampler can measure and display the temperature of the hydrothermal fluid in real time during the sampling process, which helps to find the optimal sampling point. The sampling tube selected by the device is a prefabricated part and is fixed on the sampler body without considering the orientation of the subsea hydrothermal fluid vent or the depth of the hydrothermal fluid vent, resulting in poor practicability. Summary of the Invention

[0006] The purpose of the present invention is to provide an underwater autonomous vehicle equipped with a highly flexible sampling robotic arm to cope with the real and complex sampling tasks of subsea hydrothermal fluid vents.

[0007] To achieve the purpose of the present invention, an underwater autonomous vehicle for subsea fixed-point sampling is provided, including an underwater robot body and a sampling device mounted on the underwater robot body. The sampling device includes a sampling arm and a sampling cylinder fixed on the underwater robot body, and a telescopic sampling head provided at the free rotating end of the sampling arm for extracting liquid samples. A hose for transporting the liquid sample is provided between the telescopic sampling head and the sampling cylinder;

[0008] The sampling arm includes a bracket provided on the underwater robot body, and a multi-section connected bionic joint assembly provided on the bracket. Each bionic assembly includes a plurality of skeleton units connected head to tail in sequence and a soft rope for connecting the plurality of skeleton units in series. A return spring arranged parallel to the series direction of the soft rope is provided between adjacent two skeleton units, and a vertical winch mechanism or a horizontal winch mechanism for adjusting the pulling direction of the soft rope is provided. The swinging directions of adjacent two bionic joint assemblies are orthogonally arranged;

[0009] Each skeleton unit is provided with a through hole, and when a plurality of skeleton units are connected in series, a joint channel for the hose to pass through is formed through the through holes.

[0010] The present invention increases the sampling flexibility of the underwater autonomous vehicle in the seabed through the bionic joint assembly and the telescopic sampling head.

[0011] Specifically, the telescopic sampling head includes a sampling head, an outer tube, a middle tube, and an inner tube that are coaxially arranged from outside to inside, as well as a telescopic mechanism that drives the inner tube to move relative to the middle tube and the outer tube. The inner tube is provided with a hose passage for the hose to pass through. The sampling head is communicated with the hose through the hose passage. The telescopic mechanism includes a guide rail arranged outside the outer tube and a synchronous belt clamping plate that is slidably matched with the guide rail, as well as a synchronous belt motor that provides power for the axial movement of the synchronous belt clamping plate along the tube. The outer tube and the middle tube are both provided with avoidance grooves along the tube axis direction. The synchronous belt clamping plate is fixedly connected to the inner tube through the avoidance grooves to drive the inner tube to move, so as to adapt to the sampling tasks in different postures.

[0012] Specifically, a limiting plate parallel to the end of the middle tube is provided at the extending end of the inner tube. A plurality of limiting rods parallel to the axis of the middle tube are provided at one end of the limiting plate opposite to the end of the middle tube. Avoidance holes for the limiting rods to pass through are provided at the end of the middle tube.

[0013] Specifically, the vertical winch mechanism includes a vertical winch and a vertical winch motor arranged on the bracket, and joint winches arranged on each skeleton unit. The soft rope passes through the vertical winch and is sequentially wound around the joint winches on each skeleton unit along the series direction of the skeleton units.

[0014] Specifically, the horizontal winch mechanism includes a horizontal winch and a horizontal winch motor arranged on the bracket, and a plurality of joint winches arranged at the joints of adjacent skeleton units. The plurality of joint winches are arranged in a staggered manner on both sides with the joint as the center line, and the number of joint winches on the relatively swinging side is greater than the number of joint winches on the relatively fixed side. The soft rope passes through the horizontal winch and is sequentially wound around the plurality of joint winches at each joint along the series direction of the skeleton units in a staggered manner. The staggered winding passes through the joint winches on both sides in a snake shape with the joint as the center line, so as to ensure the stability during swinging.

[0015] Specifically, the hose is equipped with a sampling cylinder assembly that adapts to stretching changes. The sampling assembly is sequentially provided with a shrinkage winding device for adjusting the elongation of the hose, a water pump for providing power for the flow of the liquid sample in the hose, and a multi-way valve for diverting the liquid sample along the flow direction of the liquid sample in the hose.

[0016] Specifically, the shrinkage winding device includes a bracket and a housing fixed on the bracket. A fixed shaft, a turntable that rotates with the fixed shaft, and a spiral spring are arranged in the housing. Two hole positions for the hose to pass through are provided on the housing. After passing through the hole positions, the hose enters the housing, winds around the turntable, and then leaves the housing through another hole position. The recovery direction of the spiral spring is opposite to the winding direction of the hose.

[0017] Specifically, the underwater robot body is also equipped with a vision control system for controlling the sampling device. The vision control system includes a binocular camera and a lighting device arranged on the underwater robot body, as well as an image recognition device for identifying the position of the submarine hydrothermal vent in the input image, so as to improve the accuracy of sampling.

[0018] Specifically, there are multiple sampling cylinders, and the multiple sampling cylinders are arranged side by side or stacked in a staggered manner. When arranged side by side, the storage space of the underwater autonomous vehicle can be effectively utilized. When stacked in a staggered manner, the problem that the underwater autonomous vehicle is affected by the shaking of the liquid sample in the sampling cylinder can be effectively avoided.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] The bionic neck joint is adopted to replace the traditional folding link arm, so as to reduce the sampling pose control requirements of the underwater autonomous vehicle to a certain extent;

[0021] The method of arranging the soft rope and the spring on the opposite sides is adopted. Compared with the traditional method of threading the rope inside the mechanism, it can save the internal volume and provide a position for the penetration of the sampling hose, thereby optimizing the structural design of the sampling arm. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the underwater autonomous vehicle provided in this embodiment;

[0023] Figure 2 It is a schematic structural diagram of the telescopic sampling head provided in this embodiment;

[0024] Figure 3 It is a schematic structural diagram of the sampling arm provided in this embodiment;

[0025] Figure 4 It is a schematic structural diagram of the sampling cylinder assembly provided in this embodiment;

[0026] Figure 5 It is a schematic structural diagram of the underwater robot body provided in this embodiment;

[0027] Figure 6 It is a schematic working diagram of the underwater autonomous vehicle provided in this embodiment;

[0028] In the figure, 1 is a vertical thruster; 2 is a binocular camera; 3 is an underwater searchlight; 4 is a sampling arm, 41 is a steel shaft, 42 is a synchronous belt, 42-1 is a long synchronous belt, 43 is a small bearing, 44 is an outer tube, 45 is a middle tube, 46 is an inner tube, 47 is a synchronous belt clamping plate, 48 is a synchronous belt pulley, 49 is a hose, 410 is a transition pipe, 411 is a sampling head, 412 is an upper pipe clamp for rail installation, 413 is a rotating shaft, 414 is a pulley, 415 is a coupling, 416 is a bearing, 417 is a rail, 420 is a winch motor, 421 is a winch, 422 is a bracket, 423 is a first skeleton unit, 424 is a return spring, 425 is a first joint winch, 426 is a transition plate, 427 is a second skeleton unit, 428 is a hole for rail installation pipe clamp, 429 is a lower pipe clamp for rail installation, 430 is a synchronous belt motor, 431 is a second joint winch, 432 is a third joint winch, 433 is a mounting block; 5 is a lateral thruster; 6 is a sampling cylinder assembly, 60 is a shrinkage coiling device, 61 is a water pump, 62 is a water outlet hose, 63 is a sampling cylinder end cover, 64 is an eight-way valve, 65 is a mounting plate, 66 is a sampling cylinder; 01 is a lower housing, 602 is an upper side cover, 603 is a pipe column, 604 is a turntable, 605 is a coil spring, 606 is; 7 is an underwater robot body, 70 is a hatch, 71 is a cabin body, 72 is a waterproof gasket, 73 is a first partition board, 74 is a control main board, 75 is a microcomputer, 76 is a second partition board, 77 is a copper column, 78 is a nut, 79 is a battery pack. Detailed implementation manners

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] As Figure 1 shown, it is a schematic diagram of an underwater autonomous vehicle for seabed fixed-point sampling provided in this embodiment. The underwater autonomous vehicle includes an underwater robot body 7 and a sampling device mounted on the underwater robot body 7. The sampling device includes a sampling arm 4 and a sampling cylinder 66 fixed on the underwater robot body, and a telescopic sampling head provided at the free rotating end of the sampling arm 4 for extracting liquid samples.

[0031] More specifically, the underwater robot body selected in this embodiment has a wide and flat shape and can be equipped with a lateral thruster 5 and a vertical thruster 1. When starting the operation, the underwater robot body 7 can perform movements such as translation and pitching underwater and travel to the target position issued by the controller installed in the underwater robot body 7 it carries, achieving fixed-point movement. A binocular camera 2 for identifying submarine hydrothermal vents is installed on the top of the robot body 7. A ramp structure is installed behind the protection of the underwater robot body 7. Under the illumination of the underwater searchlight 3, the binocular camera 2 can obtain underwater image information. After the AUV reaches the designated position, the retractable sampler 4 carried by it can adjust its pitching and rotating angles, extend the sampling tube into the submarine hydrothermal vent to be sampled, and extract the corresponding liquid sample.

[0032] As Figure 2 shown, it is a schematic structural diagram of the retractable sampling head provided by this embodiment. The retractable sampling head adopts a three-section retractable sampling probe with a stroke exceeding 15 cm, which can penetrate into the vent to extract samples and reduce the contamination of the samples by seawater.

[0033] As Figure 3 shown, it is a schematic structural diagram of the sampling arm provided by this embodiment. The sampling arm refers to the structure of the bionic owl's neck to achieve flexible control of the sampling probe, which reduces the requirements for the pose control of the robot sampling to a certain extent. While increasing the safety distance between the robot and the target sampling area, the wire used can enhance the force-bearing capacity of the mechanism.

[0034] More specifically, the sampling head 411 is installed at the front end of the sampling arm 4 and is connected to the hose 49 by means of a transfer pipe 410. And the sampling tube 411 is connected to the inner tube 46 of the retractable sampling head through a copper column. The inner tube 46 is provided with a hose channel for the hose 49 to pass through. The sampling head 411 is communicated with the hose 49 through the hose channel. There is a steel shaft 41 between the front and rear ends of the middle tube 45. A small bearing 43 is installed at the contact between the steel shaft 41 and the middle tube 45. A synchronous pulley 48 is installed outside the steel shaft 41. Two synchronous belts 42 and 42-1 are perpendicular to each other. Two synchronous belt clamps 47 are installed on the long synchronous belt 42-1 and are fixedly connected to the inner and outer tubes.

[0035] The working process is as follows: The motor 430 connected to the synchronous belt 42 rotates forward. The motor 430 is sleeved with the guide rail 417 through the coupling 415 and the bearing 416. The guide rail 417 is positioned through the guide rail installation pipe clip hole 428, and is fixed by using the upper guide rail installation pipe clip 412 and the lower guide rail installation pipe clip 429, so that when rotating, it will move along the guide rail 417 and drive the pulley 414 to rotate. The two synchronous belt pulleys 48 at the synchronous belt 42 are coaxial, so as to conduct the rotation to the long synchronous belt 42-1. The outer tube 44 and the inner tube 46 are respectively fixed to the long synchronous belt 42-1 by using the synchronous belt clamping plates 47 and 47-1. When the long synchronous belt 42-1 rotates, the inner tube 46 and the outer tube 44 respectively move with the nodes of the long synchronous belt 42-1 to which they are fixed, so as to form a relative movement with the middle tube 45, thereby increasing the elongation of the telescopic sampling head; when the motor 430 rotates in reverse, the inner tube retracts into the middle tube, thereby shortening the elongation of the telescopic sampling head.

[0036] The sampling arm 4 provided in this embodiment includes a bracket 422 provided on the underwater robot body, and two connected bionic joint components provided on the bracket 422, and the swinging directions of the two bionic joint components are orthogonally arranged;

[0037] More specifically, the winch motor 420 and the supporting winch 421 for controlling the swinging of the two bionic joint components are installed on the bracket 422. The winch motor 420 includes a vertical winch motor and a horizontal winch motor. For the vertical winch motor, the soft rope is wound around the winch 421, and then after extending from the winch 421, it is successively wound around the first joint winches 425 on each first skeleton unit 423, and at the same time, the other side is connected for reset through the reset spring 424.

[0038] The first skeleton unit 423 and the second skeleton unit 427 are connected through the adapter plate 426, and the second skeleton unit 427 is still connected in a manner that the reset spring 424 is arranged on the opposite side of the soft rope. The horizontal winch motor controls the soft rope, and after passing through the corresponding winch 421, the soft rope is alternately wound between the second joint winches 431 and the third winches 432 at each connection point along the series direction of the second skeleton unit 427. This alternate winding snakes through the joint winches on both sides with the connection point as the center line to form an M-shaped connection shape, so as to ensure the stability during swinging.

[0039] During operation, the bending angle of the joint is controlled by controlling the winding degree of the soft rope on it by two motors to meet the operation requirements.

[0040] As Figure 4 described, the sampling cylinder assembly provided in this embodiment, and Figure 4The dotted line in it indicates the hose 49 through which the sample flows in the sampling cylinder assembly, realizing the pipeline connection among the retractable coiler 60, the water pump 61, and the sampling cylinder. Along the flowing direction of the liquid sample in the hose, there are successively arranged a retractable coiler 60 for adjusting the elongation of the hose, a water pump 61 for providing power for the liquid sample to flow in the hose, and an eight-way valve 64 for diverting the liquid sample.

[0041] More specifically, the hose 49 in the sampling arm 4 is wound around the retractable coiler 60. When winding the hose 49, the hose 49 enters the coiler from the hole position on the lower housing 606, winds around the coiling column 603 for multiple turns and then enters the inside of the coiling column. The other end of the hose 49 passes through the hole position of the upper side cover 602 and the fixed conduit 601. When the sampling probe extends, the hose in the retractable coiler 60 will extend accordingly, and at the same time, the spring 605 located below the turntable 604 will tighten. When the sampling probe retracts, driven by the spring 605, the turntable 604 rotates to rewind the hose 49 around the coiler 60.

[0042] When testing in shallow water areas, it is necessary to rely on the water pump to suck in the liquid. The water outlet of the water pump 61 is connected to the eight-way valve 64 through the water outlet hose 62, and then its 8 outlets are respectively connected to 8 sampling cylinder end caps 63, and the end caps 63 are installed on the sampling cylinder 66. The complete sampling cylinder is installed on the rack board 65. The entire sampling cylinder assembly can fill 8 sampling cylinders at a time, with a total of about 4L of samples.

[0043] Its specific working process is as follows:

[0044] When starting sampling, extend the sampling arm 4, the hose 49 in the retractable coiler 60 extends, the water pump 61 is powered on to work, the liquid is sucked into the pump body, and the opening and closing of each valve port of the eight-way valve are controlled, and finally it enters the sampling cylinder 66 through the water outlet pipe to complete the sampling.

[0045] As Figure 5 shown, it is a schematic structural diagram of the underwater robot body provided in this embodiment, mainly composed of a hatch cover 70 and a cabin body 71, and a waterproof gasket is installed at the end cover 70. The mutually perpendicular partition boards 73 and 76 are fixed at the end cover by parts such as copper columns 77 and are fixed by nuts 78. Each electronic component, such as a control board 74, a microcomputer 75, and a battery pack 79, is installed on the horizontal partition board 73.

[0046] As Figure 6 shown, it is a schematic working diagram of the underwater autonomous vehicle provided in this embodiment. Taking sampling at a hydrothermal vent as an example, its state during navigation is as Figure 6 shown in (a) in it. At this time, the sampling arm is retracted and placed horizontally. When moving to the sampling position, the sampling arm adjusts the sampling attitude through pitching and telescoping. Its state during sampling is as Figure 6 shown in (b) in it.

[0047] In summary, the underwater robot provided by the present invention is equipped with 7 thrusters, capable of achieving redundant control and fixed-point control;

[0048] The three-section telescopic sampling probe has a stroke exceeding 15 cm, which can penetrate into the nozzle to extract samples and reduce the contamination of samples by seawater;

[0049] The designed bionic owl neck platform can achieve flexible control of the sampling probe, reducing the requirements for the pose control of the robot during sampling to a certain extent. While increasing the safety distance between the robot and the target sampling area, the wire used can enhance the force-bearing capacity of the mechanism. The arrangement of the soft rope and the spring on the opposite side can save the internal volume compared with the traditional way of threading the rope inside the mechanism, providing a position for the penetration of the sampling hose;

[0050] The designed sampling cylinder assembly is equipped with a sampling hose contraction and winding mechanism, which can realize the tensioning, retracting and releasing of the hose according to the expansion and contraction of the sampling probe, preventing the hose from being stacked disorderly and occupying the internal space of the robot; equipped with 8 sampling cylinders, it can collect 6L of water samples in a single operation, and the sampling capacity can be adjusted through an 8-way valve controlled by electricity. In addition, the circuit cavity inside the underwater robot body integrates functions such as control, power supply, pressure maintenance, and graphic analysis, with rich functions and a compact structure.

[0051] In addition, the terms "upper", "lower", "inner", "outer", "front", and "rear" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Unless specifically stated otherwise, the relative steps, numerical expressions, and values of the components and steps described in these embodiments do not limit the scope of the present invention.

[0052] Of course, the above are only specific embodiments of the present invention and are not intended to limit the scope of the implementation of the present invention. Any equivalent changes or modifications made according to the structure, characteristics, and principles described in the scope of the patent application of the present invention should be included in the scope of the patent application of the present invention.

[0053] Finally, it should be noted that the above embodiments are only specific implementation manners of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present invention can still modify the technical solutions described in the foregoing embodiments or can easily think of changes, or perform equivalent replacements for some of the technical features; and these modifications, changes, or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. An underwater autonomous vehicle for sampling at a fixed point on the seabed, characterized in that: The invention comprises an underwater robot body and a sampling device mounted on the underwater robot body, wherein the sampling device comprises a sampling arm and a sampling barrel fixed on the underwater robot body, and a telescopic sampling head arranged at a freely rotating end of the sampling arm for extracting liquid samples, and a hose for conveying liquid samples is arranged between the telescopic sampling head and the sampling barrel; The sampling arm comprises a bracket arranged on the underwater robot body, and a plurality of connected bionic joint components arranged on the bracket, each bionic component comprises a plurality of skeleton units connected in sequence head to tail and a soft rope for connecting the plurality of skeleton units in series, a reset spring arranged in parallel with the series connection direction of the soft rope, and a vertical winch mechanism or a horizontal winch mechanism for adjusting the pulling direction of the soft rope are arranged between two adjacent skeleton units, the swinging directions of two adjacent bionic joint components are arranged orthogonally, the vertical winch mechanism comprises a vertical winch and a vertical winch motor arranged on the bracket and a joint winch arranged on each skeleton unit, After passing through the vertical winch, the soft rope is sequentially wound with the joint winch on each skeleton unit along the serial direction of the skeleton units. The horizontal winch mechanism includes a horizontal winch and a horizontal winch motor arranged on the bracket and a plurality of joint winches arranged at the connection of adjacent skeleton units. The plurality of joint winches are staggered on both sides with the connection as the center line, and the number of joint winches on the relatively swinging side is greater than the number of joint winches on the relatively fixed side. After passing through the horizontal winch, the soft rope is sequentially wound with the plurality of joint winches at each connection along the serial direction of the skeleton units. The staggered winding passes through the joint winches on both sides in a serpentine shape with the connection as the center line. Each skeleton unit is provided with a through hole, and when a plurality of skeleton units are connected in series, a joint channel for the hose to pass through is formed through the through holes.

2. The underwater autonomous vehicle for fixed-point sampling on the seabed according to claim 1, characterized in that: The telescopic sampling head includes a sampling head, an outer tube, a middle tube and an inner tube coaxially arranged from the outside to the inside, and a telescopic mechanism for driving the inner tube to move relative to the middle tube and the outer tube. The inner tube is provided with a hose channel for a hose to pass through, and the sampling head is connected with the hose through the hose channel. The telescopic mechanism includes a guide rail provided on the outer side of the outer tube and a synchronous belt clamp plate slidably matched with the guide rail, and a synchronous belt motor providing power for the synchronous belt clamp plate to move along the axial direction of the tube. The outer tube and the middle tube are both provided with avoidance grooves along the axial direction of the tube, and the synchronous belt clamp plate is fixedly connected to the inner tube through the avoidance groove to drive the inner tube to move.

3. The underwater autonomous vehicle for fixed-point sampling on the seabed according to claim 2 is characterized in that: The extended end of the inner tube is provided with a limit plate arranged parallel to the end of the middle tube, the end of the limit plate opposite to the end of the middle tube is provided with a plurality of limit rods parallel to the axial direction of the middle tube, and the end of the middle tube is provided with an avoidance hole for the limit rod to pass through.

4. The underwater autonomous vehicle for fixed-point sampling on the seabed according to claim 1, characterized in that: The hose is equipped with a sampling barrel assembly with adaptive stretching changes. The sampling barrel assembly is provided with a shrinking tube wrap for adjusting the elongation of the hose, a water pump for providing power for the liquid sample to flow in the hose, and a multi-way valve for diverting the liquid sample in sequence along the flow direction of the liquid sample in the hose.

5. The underwater autonomous vehicle for fixed-point sampling on the seabed according to claim 4, characterized in that: The shrink tube winder includes a bracket and a shell fixed on the bracket, wherein a fixed shaft, a turntable rotating with the fixed shaft, and a coil spring are arranged in the shell, and the shell has two holes for the hose to pass through. The hose enters the shell through the hole and is wound around the turntable and leaves the shell through another hole, and the recovery direction of the coil spring is opposite to the winding direction of the hose.

6. The underwater autonomous vehicle for fixed-point sampling on the seabed according to claim 1, characterized in that: The underwater robot body is also equipped with a visual control system for controlling the sampling device, which includes a binocular camera and a lighting device arranged on the underwater robot body, and an image recognition device for identifying the position of the seabed hydrothermal vent in the input image.

7. The underwater autonomous vehicle for fixed-point sampling on the seabed according to claim 1, characterized in that: There are multiple sampling barrels, and the multiple sampling barrels are arranged side by side or staggered and stacked.

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