Deep sea distributed sound wave sensing system for autonomously laying long-distance micro optical cable

Abstract

The invention comprises a deep-sea distributed sound wave sensing system for autonomously laying long-distance micro optical cables, and the system comprises a deep-sea crawling robot which is used for autonomously moving on the seabed; the optical cable laying and coupling device is installed on the deep-sea crawling robot and comprises a deep-sea coulter for cutting seabed sediments to form a groove. The ballast part is used for pressing the micro optical cable into the seabed sediment and providing horizontal traction resistance; the releasing device is used for releasing the micro optical cable; the diameter of the micro optical cable is 8-10 microns, and the micro optical cable is continuously released by the release device and embedded in the groove; power driving and autonomous navigation are achieved through the deep sea crawling robot, the load limitation of a traditional optical cable is broken through in combination with a micro optical cable with the diameter being only 8-10 microns, and long-distance laying of tens of kilometers to hundreds of kilometers is achieved; according to the optical cable laying and coupling device, deep sea coulter slotting, traction resistance provided by a ballast component and sediment coupling plate compaction and backfilling are utilized, strong coupling of an optical cable and a seabed is remarkably enhanced, underflow disturbance is reduced, and stability and quality of observation signals are greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of deep sea monitoring technology, and in particular to a deep sea distributed acoustic wave sensing system with autonomously laid long-distance micro-optical cables. Background Art

[0002] Existing deep-sea distributed acoustic sensing (DAS) systems primarily rely on fixed submarine optical cables or optoelectronic composite cables as sensing carriers. These systems require large, specialized cable-laying vessels, resulting in high costs. Furthermore, the sensing area is strictly limited to the vicinity of the optical cable route, making it impossible to achieve flexible, mobile observations in deep-sea areas. Furthermore, these systems require bulky, power-hungry demodulation equipment located on land, relying on shore-based power and timing. Limited by backscatter noise, their effective sensing range typically struggles to exceed 190 kilometers, significantly restricting their application in the vast deep sea.

[0003] To increase flexibility, existing technologies have proposed deploying miniaturized demodulators and small-diameter optical cables using deep-sea landers or manned submersibles. However, while these cables are lighter than communication cables (approximately 18kg / km), their weight (e.g., 180kg for 10km) far exceeds the conventional carrying capacity of underwater platforms when laid over long distances of tens to hundreds of kilometers, making construction extremely difficult. Furthermore, these cables rely solely on their own weight and platform tension to achieve seabed coupling, making it difficult to fully bury them in the sediment. Consequently, insufficient coupling strength results in a significant degradation of signal quality in the undercoupled section, impacting observation accuracy. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention provides a deep-sea distributed acoustic wave sensing system with autonomous laying of long-distance micro-optical cables, aiming to solve the problems existing in the above-mentioned background technology.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solutions: a deep-sea distributed acoustic wave sensing system for autonomously laying long-distance micro-optical cables, characterized in that it includes: a deep-sea crawling robot, which provides power for autonomous movement on the seabed, an optical cable laying coupling device, which is installed on the deep-sea crawling robot, including a deep-sea plow for cutting seabed sediments to form grooves, a ballast component for pressing the micro-optical cable into the seabed sediments and providing horizontal traction resistance to the micro-optical cable, a release device for releasing the micro-optical cable and a sediment coupling plate for compacting the backfill sediments, and the micro-optical cable, with a diameter of 8-10 μm, is continuously released by the release device and buried in the groove.

[0006] Furthermore, the micro optical cable includes an optical fiber, which is a gradient enhanced scattering optical fiber, a coating layer wrapped around the outside of the optical fiber, a Kevlar fiber braided reinforcement layer wrapped around the outside of the coating layer, and an outer sheath wrapped around the outside of the reinforcement layer.

[0007] Furthermore, the releasing device is an optical cable releasing box provided on the deep-sea crawling robot, and an optical cable guide is provided on the deep-sea plow, which is used to guide the optical fiber to the bottom of the groove. An armored optical cable is fixed on the optical cable ballast, and the optical fiber guided from the lower part of the deep-sea plow enters the armored optical cable.

[0008] Furthermore, an optical cable unwinding wheel is provided between the optical cable release box and the optical cable guide rail, and the released optical cable passes around the optical cable unwinding wheel and enters the optical cable guide rail.

[0009] Furthermore, the deep-sea crawling robot is equipped with a main control cabin and an oil-filled junction box. The main control cabin has a built-in navigation and path planning module. The main control cabin processes the path planning information through the oil-filled junction box to realize the autonomous laying of L-shaped, U-shaped, square or hexagonal topology optical cable networks.

[0010] Furthermore, it also includes a ballast release controller arranged on the deep-sea crawling robot for releasing the optical cable ballast, and the optical cable ballast release controller fixes the optical cable ballast through electromagnet adsorption.

[0011] Furthermore, the optical cable ballast release controller has dual modes of underwater timed release and acoustic release.

[0012] Furthermore, it also includes a fine optical cable cutting controller with dual modes of underwater timed cutting and acoustic command cutting, which is used to cut the optical cable before the deep-sea crawling robot surfaces.

[0013] Furthermore, the deep-sea crawling robot has an integrated DAS demodulator that directly analyzes the acoustic wave signals of the tiny optical cables buried in the seabed.

[0014] Furthermore, the DAS demodulator includes a pressure-resistant cabin arranged on the deep-sea crawling robot, an optical phase demodulation module, a GPS positioning and timing module, a heat dissipation module, a power management module, a control communication module, a switch and a dry-wet connection module arranged in the pressure-resistant cabin.

[0015] The present invention describes a deep-sea distributed acoustic wave sensing system for autonomously laying long-distance micro-optical cables. Its beneficial effects are: power drive and autonomous navigation are achieved through deep-sea crawling robots, combined with micro-optical cables with a diameter of only 8-10μm, breaking through the load limitations of traditional optical cables and achieving long-distance laying of tens to hundreds of kilometers; the optical cable laying coupling device uses deep-sea plow cutters to open grooves, ballast components to provide traction resistance, and sediment coupling plates for compaction and backfilling, which significantly enhances the strong coupling between the optical cable and the seabed, reduces bottom current disturbances, and greatly improves the stability and quality of the observation signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of a deep-sea distributed acoustic wave sensing system according to an embodiment of the present invention;

[0017] Figure 2is a schematic diagram of a deep-sea crawling robot according to an embodiment of the present invention;

[0018] Figure 3 is an exploded view of the structure of a micro optical cable according to an embodiment of the present invention;

[0019] Figure 4 is a structural diagram of an optical cable laying coupling device according to an embodiment of the present invention;

[0020] Figure 5 is a structural diagram of an optical cable release box according to an embodiment of the present invention;

[0021] Figure 6 is a structural diagram of a DAS demodulator according to an embodiment of the present invention;

[0022] Figure 7 This is a diagram showing the connection of components of a DAS demodulator according to an embodiment of the present invention.

[0023] Description of the accompanying symbols: deep-sea crawling robot 1, optical cable laying coupling device 2, deep-sea plow 201, ballast component 202, sediment coupling plate 203, optical cable release box 204, optical cable guide 205, armored optical cable 206, optical cable unwinding wheel 207, optical cable cutting controller 208, ballast release controller 209, micro optical cable 3, optical fiber 301, coating layer 302, reinforcement layer 303, outer sheath 304, oil-filled junction box 4, main control cabin 5, pressure-resistant cabin 6, DAS demodulator 7, optical phase demodulation module 8, GPS positioning and timing module 9, heat dissipation module 10, Power management module 11, control communication module 12, switch 13, dry and wet connection module 14, photoelectric demodulation unit 15, data processing unit 16, linewidth laser 17, first modulator 18, isolator 19, fiber amplifier 20, fiber Bragg grating 21, circulator 22, Faraday rotator 23, phase modulator 24, 3dB coupler 25, photodetector 26, fiber pressure-resistant cabin penetration component 27, elastic bearing shaft 28, Linux operating system 29, Xilinx dual-core processor 30, RAM memory 31, 28nm low-power Kintex-7 FPGA field programmable gate array chip 32, basic memory 33, low-power memory 34, analog-to-digital converter 35, digital-to-analog converter 36, peripheral device module 37, control computer 38, parameter setting and data display software 39, external network storage 40, ultra-large capacity built-in hard disk 41, clock controller 42, high-precision trigger timer 43, large-capacity battery 44, load dumping 45, acoustic releaser 46, motor 47, crawling track 48, buoyancy material 49, sonic transducer 50, star 51, strobe light 54, tension control curved tube 55, status indicator light 56, optical cable reel 57. DETAILED DESCRIPTION

[0024] Typical embodiments embodying the features and advantages of the present invention are described in detail in the following description. It should be understood that the present invention is capable of various variations in different embodiments without departing from the scope of the present invention, and that the descriptions and illustrations herein are intended to be illustrative rather than limiting.

[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0026] In order to further illustrate the principle and structure of the present invention, preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0027] like Figure 1-7 As shown, an embodiment of the present invention provides a deep-sea distributed acoustic wave sensing system for autonomously laying long-distance micro-optical cables 3. The system is mainly composed of a deep-sea crawling robot 1, an optical cable laying coupling device 2 and a micro-optical cable 3.

[0028] Among them, the deep-sea crawling robot 1 serves as the mobile carrier and power source of the entire system, and can move autonomously on the deep seabed, providing a stable moving foundation for the subsequent optical fiber 301 laying operation.

[0029] The optical cable laying coupling device 2 is installed on the deep-sea crawling robot 1. It is a key component for realizing the coupling of the laying of the optical fiber 301 with the seabed. It contains multiple functional components, including: a deep-sea plow 201, a ballast component 202, a release device and a sediment coupling plate 203; the deep-sea plow 201 is used to cut the seabed sediment during the movement of the robot, thereby forming a groove with a depth of ≥10 cm for the burial of the micro-optical cable 3; the ballast component 202 can press the micro-optical cable 3 into the seabed sediment and apply horizontal traction resistance to the micro-optical cable 3 to ensure that the micro-optical cable 3 remains in a tensioned state without loosening during the laying process; the release device is used to continuously release the micro-optical cable 3 to provide an optical cable source for long-distance laying; the sediment coupling plate 203 follows the deep-sea plow 201 and can compact and backfill the sediment around the groove so that the buried micro-optical cable 3 is tightly combined with the seabed sediment.

[0030] Furthermore, to address the problem that small-diameter optical cables are bulky and limit long-distance laying, the present invention uses a micro-optical cable 3 with a diameter of only 8-10μm. The underwater weight of a 10km length is only 2-4kg, which greatly reduces the laying load and makes deep-sea observations over long distances and large cross-sections of tens to hundreds of kilometers possible, overcoming the limitations of the limited carrying capacity of platforms such as manned submersibles.

[0031] During operation, the deep-sea crawling robot 1 moves autonomously on the seabed, driving the optical cable laying coupling device 2 installed on it to move synchronously; during this process, the deep-sea plow 201 continuously cuts the seabed sediment to form a groove ≥10 cm; at the same time, the releasing device continuously releases the micro-optical cable 3 with a diameter of 8-10 μm, and the ballast component 202 presses one end of the micro-optical cable 3 into the bottom of the groove, and the ballast component 202 sinks into the sediment to generate horizontal traction resistance; then, the sediment coupling plate 203 pushes the sediment on both sides of the groove back into the groove and compacts it, completing the strong coupling of the micro-optical cable 3 with the seabed, effectively reducing the impact of bottom current disturbances on the optical fiber 301, and significantly improving the stability and quality of the observation signal.

[0032] The deep-sea crawler robot 1, serving as the system's core mobility and control vehicle, utilizes a highly modular design, integrating key functional modules such as power, navigation, control, communications, and energy supply. This provides comprehensive support for the autonomous installation of long-distance, micro-optical cables 3. Its key internal and external components work in tandem to enable deep-sea entry, precise seabed crawling, autonomous path planning, and post-operation recovery.

[0033] The deep-sea crawling robot 1 includes a large-capacity battery 44, a main control cabin 5, an oil-filled connection box 4, a motor 47, and a deep-sea DAS demodulator 7. The exterior is equipped with a crawling track 48, an acoustic releaser 46, a jettisoning load 45, a buoyancy material 49, an acoustic transducer 50, a status indicator light 56, a strobe light 52, and a star 51. Each component is mechanically fixed and connected to the circuit to form a complete operating system.

[0034] The high-capacity battery 44, serving as the core energy component, is directly connected to the oil-filled junction box 4 via wires. The oil-filled junction box 4, acting as a power distribution and signal relay hub, connects to the motor 47, main control cabin 5, deep-sea DAS demodulator 7, optical cable ballast release controller 209, micro-cable 3 shear controller 208, acoustic releaser 46, acoustic transducer 50, status indicator 56, strobe light 52, and Iris 51, enabling power distribution and the transmission of commands and status signals. The motor 47 drives the crawler tracks 48. The main control cabin 5 controls the robot's autonomous crawling along a pre-set path via the oil-filled junction box 4. The deep-sea DAS demodulator 7 analyzes the optical cable signals in real time, jointly ensuring the cable laying operation.

[0035] Specifically, the main control cabin 5 is connected to the oil filling junction box 4 through a data line. On the one hand, it receives the operating status signals of various components transmitted by the oil filling junction box 4 (such as battery power, motor 47 speed, DAS demodulator 7 working status, etc.), and on the other hand, it sends control instructions to the oil filling junction box 4, which are transferred to the motor 47, ballast release controller 209 and other execution components; at the same time, the main control cabin 5 has a built-in navigation and path planning module, which combines the forward-looking sonar and inertial navigation data, adjusts the operating parameters of the motor 47 through the oil filling junction box 4, controls the steering and speed of the track 48, realizes the autonomous laying of L-shaped, U-shaped, square or hexagonal topology optical cable networks, and completes obstacle avoidance operations.

[0036] Deep sea entry process

[0037] The deep-sea crawling robot 1 is hoisted and dropped into the sea by a surface mother ship. During the drop, the dump load 45 is connected to the acoustic releaser 46 to provide additional counterweight for the robot. Under the action of its own weight and the gravity of the dump load 45, the robot overcomes part of the buoyancy of the buoyancy material 49 and dives at a stable speed. During the dive, the oil-filled junction box 4 continuously supplies power to the acoustic transducer 50 and the status indicator light 56: the acoustic transducer 50 receives the acoustic instructions from the mother ship and provides real-time feedback on the diving depth and equipment status; the status indicator light 56 ​​flashes at a fixed frequency, indicating that the equipment is operating normally. After reaching the seabed, the weight of the dump load 45 enables the robot to land firmly on the sediment surface, avoiding displacement caused by bottom current disturbances.

[0038] Floating recovery process

[0039] When the robot completes the optical cable laying operation, or receives an acoustic surfacing command from the mother ship, or reaches the preset surfacing time, the main control cabin 5 sends a release command to the acoustic releaser 46 through the oil-filled junction box 4. The acoustic releaser 46 immediately unhooks, and the jettison 45 detaches from the robot and sinks to the seabed; at this time, the buoyancy provided by the buoyancy material 49 is greater than the remaining total gravity of the robot, driving the robot to float upward. After surfacing to the water surface, the oil-filled junction box 4 triggers the strobe light 52 to enter flashing mode, using strong light signals to assist the mother ship in observation and positioning. At the same time, the satellite 51 starts working and sends the robot's real-time surface position information to the orbiting satellite. The satellite then transmits the position information to the user's mailbox and handheld receiver via the network, ensuring that the mother ship can quickly lock on to the target and efficiently complete equipment recovery.

[0040] Furthermore, the micro-optical cable 3 of the present invention adopts a multi-layer composite structure design, which ensures full-sea-depth pressure resistance and strong tensile strength resistance while achieving a lightweight characteristic of only 8-10μm in diameter (10km weighs 2-4kg). Its specific layered structure is as follows:

[0041] Micro optical cable 3 includes optical fiber 301, coating 302 covering the outside of optical fiber 301, reinforcement layer 303 covering the outside of coating 302, and outer sheath 304 covering the outside of reinforcement layer 303. Optical fiber 301 is a gradient-enhanced scattering optical fiber 301, which effectively suppresses low-frequency noise and transmission loss. Coating 302 is made of UV-curable acrylic resin, which buffers external stress and prevents microbending losses in optical fiber 301. Reinforcement layer 303 is woven from a large number of Kevlar fibers to increase tensile strength. Outer sheath 304 can be made of existing high-abrasion-resistant materials.

[0042] The following is a detailed description of the optical cable laying coupling device 2

[0043] Furthermore, the release device is a cable release box 204 fixed to the back of the deep-sea crawler 1. It houses a rotatable reel for the fine optical cable 3. A constant-tension drive mechanism enables continuous and stable release of the optical cable, providing a continuous source of optical fiber 301 for long-distance laying. A cable guide 205, constructed of titanium alloy and shaped like an arc-shaped tubular structure, is fixed to the deep-sea plow cutter 201. Its inlet aligns with the cable output direction of the cable release box 204, while its outlet precisely aligns with the bottom of the trench cut by the deep-sea plow cutter 201. When the cable release box 204 releases the fine optical cable 3, it is guided by the guide structure into the cable guide 205. Under the guidance of the guide, it smoothly extends along the arc path to the bottom of the trench, ensuring that the cable falls accurately into the pre-set burial position and providing precise initial positioning for the subsequent insertion of the ballast component 202 and the compaction and backfilling of the sediment coupling plate 203.

[0044] Furthermore, the guiding structure is a cable unwinding wheel 207 positioned between the release box and deep-sea coulter 201. The released cable is guided by the unwinding wheel 207 into the cable guide 205, which is machined with spiral grooves. The released cable bypasses the unwinding wheel grooves, eliminating the torsional stress accumulated by the reel winding. The cable guide 205 is integrated into the rear end of the deep-sea coulter 201. This titanium alloy curved tube precisely guides the cable from the unwinding wheel to the bottom of the groove.

[0045] Furthermore, the deep-sea crawling robot 1 is equipped with a ballast release controller 209 (not shown). The ballast release controller 209 is fixedly mounted on the rear of the deep-sea crawling robot 1. Its core component is an electromagnet assembly (not shown), which can form a stable adsorption with the optical cable ballast. The optical cable ballast adopts a square iron block structure weighing 10-20kg. Initially, the electromagnet of the ballast release controller 209 remains energized, firmly fixing the optical cable ballast through magnetic force, ensuring that it moves synchronously with the robot. The ballast release controller 209 has dual modes of underwater timed release and acoustic release. When it receives a timed instruction from the main control cabin 5 or an acoustic signal from the surface mother ship, the electromagnet is de-energized and demagnetized, and the optical cable ballast immediately detaches from the controller and sinks into the sediment under its own weight. When the optical cable needs to be laid, the ballast sinks into the seabed sediment, providing a continuous and stable horizontal traction resistance for the fine optical cable 3, preventing the optical cable from loosening. Continuously maintaining the traction tension of the optical cable ensures the tension state and laying accuracy of the optical cable during long-distance laying.

[0046] Furthermore, the cable ballast is secured with an armored, pressure-resistant optical cable, 1-2 meters long and embedded with a crush-resistant steel wire sheath (not shown). The optical cable, exiting from the lower portion of the deep-sea plow 201, first enters this armored cable 206 before extending to the ballast component 202. The armored section, through the steel wire sheath, distributes vertical pressure, ensuring the cable is protected from damage during sediment compaction.

[0047] Furthermore, the deep-sea crawling robot 1 is equipped with a micro-cable 3 shearing controller 208. This controller is fixedly mounted between the cable release box 204 and the cable unwinding wheel 207, and is located along the cable release path. It integrates a movable cutter and a control module. Its power and signal lines are connected to the oil-filled junction box 4, and it is controlled collaboratively by the main control cabin 5. This controller has dual underwater timed shearing and acoustic command shearing modes. When the deep-sea crawling robot 1 completes the cable laying operation or reaches the preset shearing time, the timing module triggers the control command, causing the electromagnet within the controller to rapidly engage the cutter, severing the micro-cable 3. If an acoustic shearing command is received from a surface mother ship via an acoustic transducer 50, the control module similarly activates the cutter to complete the shearing process. This can separate the laid micro-optical cable 3 from the robot body before the robot surfaces, ensuring that the optical cable remains on the seabed for continuous observation. The robot surfaces with a light load to avoid interference with the recovery process caused by dragging the optical cable. The dual-mode design provides double protection for the cutting action and improves operational reliability.

[0048] Furthermore, an optical cable reel 57 is provided in the optical cable release box 204 , and a tension control curved tube 53 is provided at the outlet of the optical cable release box 204 . The tension control curved tube 53 is used to reduce the instantaneous tension of the deep-sea tensile micro-optical cable 3 .

[0049] As an embodiment of the DAS demodulator, the DAS demodulator is encapsulated in a full-sea-depth pressure-resistant cabin. The pressure-resistant cabin is fixed inside the robot through a mechanical structure. Its power interface is connected to the oil-filled junction box. While receiving power, it feeds back demodulated data to the main control cabin through a data line. The pressure-resistant cabin is made of a titanium alloy and is horizontally and vertically sealed by multiple sets of O-rings. It can withstand full-sea-depth water pressure. The DAS demodulator includes an optical phase demodulation module, a GPS positioning and timing module, a heat dissipation module, a power management module, etc. It can analyze the phase changes of the backscattered light transmitted back by the fine optical cable in real time, and realize in-situ demodulation and data storage of deep-sea sound waves, vibrations and other signals.

[0050] Specifically, the power management module 11 regulates the current and voltage of the entire system; the GPS positioning, timing and timekeeping module 9 has functions such as positioning, timing and timekeeping; the control communication module 12 communicates with the host computer through the TCP / IP protocol, can set the current system time, set the working time of the optical phase demodulation module 8, and transmit the collected system voltage, current, temperature, water leakage, power insulation status and other data to the host computer, and store them in the SD card at the same time; the switch 13 provides network connection for the optical phase demodulation module 8, the control communication module 12 and the host computer; the GPS positioning, timing and timekeeping module 9 is connected to the clock controller 42, realizing the clock synchronization of the internal modules of the DAS demodulator 7, and the underwater cumulative drift error is less than milliseconds.

[0051] Furthermore, the optical phase demodulation module 8 includes a photoelectric adjustment unit and a data processing unit 16. The photoelectric adjustment unit includes a line width laser 17, a first modulator 18, an isolator 19, an optical fiber amplifier 20 and a circulator 22 connected in sequence, and a fiber grating 21 is connected to one end of the circulator 22.

[0052] In a specific embodiment, the optoelectronic demodulation unit 15 adopts a phase-generated carrier PGC demodulation algorithm to reduce the complexity of optical phase demodulation, exponentially reduce the number of operations, and reduce the requirements for high-performance, high-power chips and circuits. The data processing unit 16 adopts a Kintex-7 FPGA chip with low power consumption, small size, and high-density computing resources, an ARM architecture Linux operating system with high-efficiency computing, and a Xilinx dual-core processor, realizing real-time demodulation of the optical phase by low-power hardware operation of the PGC algorithm.

[0053] Furthermore, the optical phase demodulation module 8 also includes a phase modulator 24 and a 3dB coupler 25. The 3dB coupler 25 is respectively connected to the Faraday rotator 23, the photodetector 26 and the circulator 22. The phase modulator 24, the first modulator 18 and the photodetector 26 are connected to the data processing unit 16.

[0054] In a specific embodiment, a Faraday rotator mirror 23, a phase modulator 24, a coupler and a photodetector 26 constitute a Michelson interferometer, and the data processing unit 16 is mainly composed of a Linux operating system 29, a Xilinx dual-core processor 30, a RAM memory 31, a 28nm low-power Kintex-7 FPGA field programmable gate array chip 32, a basic memory 33, a low-power memory 34, an analog-to-digital converter 35, a digital-to-analog converter 36, and a peripheral device module 37.

[0055] Furthermore, the data processing unit 16 includes a conversion module connected to the phase modulator 24 , the first modulator 18 and the photodetector 26 , and a programming module connected to the conversion module.

[0056] In a specific embodiment, the conversion module includes an analog-to-digital converter 35 and a digital-to-analog converter 36 , and the programming module includes a 28nm low-power Kintex-7 FPGA field programmable gate array chip 32 , a basic memory 33 , and a low-power memory 34 .

[0057] Furthermore, the data processing unit 16 also includes an operating system and a peripheral device module, and the operating system is connected to the peripheral module and the programming module respectively.

[0058] In a specific embodiment, the operating system includes a Linux operating system 29, a Xilinx dual-core processor 30, and a RAM memory 31. The peripheral module 37 includes a control computer 38, parameter setting and data display software 39, an external network storage 40, an ultra-large capacity built-in hard disk 41, a clock controller 42, and a high-precision trigger timer 43, which has the function of assisting the system to complete data storage and communication control functions.

[0059] The above are merely preferred embodiments of the present invention and do not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying, characterized by: include: Deep-sea crawling robots, which provide power for autonomous movement on the seabed; An optical cable laying coupling device, installed on a deep-sea crawling robot, comprising a deep-sea plow for cutting seabed sediment to form a groove, a ballast component for pressing a micro-optical cable into the seabed sediment and providing horizontal pulling resistance to the micro-optical cable, a release device for releasing the micro-optical cable, and a sediment coupling plate for compacting backfill sediment; Micro optical cables, with a diameter of 8-10μm, are continuously released by a releasing device and buried in the groove.

2. The deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying according to claim 1 is characterized in that: The micro optical cable includes an optical fiber, which is a gradient enhanced scattering optical fiber, a coating layer wrapped around the outside of the optical fiber, a Kevlar fiber braided reinforcement layer wrapped around the outside of the coating layer, and an outer sheath wrapped around the outside of the reinforcement layer.

3. The deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying according to claim 1 is characterized in that: The releasing device is an optical cable releasing box installed on the deep-sea crawling robot. An optical cable guide is provided on the deep-sea plow. The optical cable guide is used to guide the optical fiber to the bottom of the groove. An armored optical cable is fixed on the optical cable ballast. The optical fiber guided from the lower part of the deep-sea plow enters the armored optical cable.

4. The deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying according to claim 3 is characterized in that: An optical cable unwinding wheel is also provided between the optical cable release box and the optical cable guide rail, and the released optical cable passes around the optical cable unwinding wheel and then enters the optical cable guide rail.

5. The deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying according to claim 1 is characterized in that: The deep-sea crawling robot is equipped with a main control cabin and an oil-filled junction box. The main control cabin has a built-in navigation and path planning module. The main control cabin processes path planning information through the oil-filled junction box to realize the autonomous laying of L-shaped, U-shaped, square or hexagonal topology optical cable networks.

6. The deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying according to claim 1 is characterized in that: It also includes a ballast release controller 209 arranged on the deep-sea crawling robot for releasing the optical cable ballast. The optical cable ballast release controller 209 fixes the optical cable ballast by adsorbing and fixing the optical cable ballast through an electromagnet.

7. The deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying according to claim 6 is characterized in that: The optical cable ballast release controller 209 has dual modes of underwater timed release and acoustic release.

8. The deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying according to claim 1 is characterized in that: It also includes an optical cable cutting controller with dual modes of underwater timed cutting and acoustic command cutting, which is used to cut the optical cable before the deep-sea crawling robot surfaces.

9. The deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying according to claim 1 is characterized in that: The deep-sea crawling robot has an integrated DAS demodulator that directly analyzes the acoustic wave signals of the tiny optical cables buried in the seabed.

10. The deep-sea distributed acoustic wave sensing system with autonomous long-distance micro-optical cable laying according to claim 1 is characterized in that: The DAS demodulator includes a pressure-resistant cabin installed on the deep-sea crawling robot, an optical phase demodulation module, a GPS positioning and timing module, a heat dissipation module, a power management module, a control and communication module, a switch and a dry and wet connection module installed in the pressure-resistant cabin.

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