Measuring device based on underwater form self-sensing intelligent cable

Abstract

The invention discloses a measuring device based on an underwater form self-sensing intelligent cable, and belongs to the technical field of ocean engineering. The device is used for collecting underwater acoustic signals, electric field data and magnetic field data in a marine environment, introducing an inertial measurement unit (IMU) to obtain attitude angles and / or position information of measurement nodes, and carrying out space-time calibration and vectorization processing on multi-source measurement data. The device comprises a waterproof sealed titanium alloy streamline measuring box, an internal integrated microcontroller (MCU), various sensors, an IMU (Inertial Measurement Unit) and a communication module, a power supply line, a communication line and a fiber grating sensor are arranged in the intelligent cable. And the MCU associates the sensing data with the pose information to generate data with a space-time label, and the data are transmitted through an optical fiber after short-distance electro-optical conversion and long-distance electro-optical conversion through a CAN (Controller Area Network) bus. Multiple nodes are connected in series to transmit data to an upper computer, low-resistance and anti-winding characteristics are achieved, multi-parameter long-distance real-time acquisition and cable form self-sensing are achieved, the data value is high, and the environmental adaptability is good.

Description

Technical Field

[0001] This invention relates to a measurement device based on an underwater morphology self-sensing smart cable, which belongs to the field of marine engineering technology. Background Technology

[0002] With the continuous advancement of marine information and intelligent sensing technologies, especially the increasing demands for real-time, continuous, and accurate underwater long-term observation, integrated deployment from offshore platforms to sensing terminals, and underwater survey operations, existing underwater detection devices face numerous challenges in terms of functional integration, data transmission, and structural reliability.

[0003] Existing underwater detection devices have the following problems: 1) Traditional underwater detection systems often focus on acquiring single or limited physical quantities. For example, some systems only detect underwater electromagnetic signals, requiring ultra-low noise signal detection and amplification techniques to achieve high-precision acquisition. However, this single-physical-quantity acquisition mode limits the comprehensive understanding of complex marine environmental information. Although some integrated detection systems exist in the current technology, they often have low integration levels, making it difficult to achieve simultaneous, high-precision, and low-noise acquisition of multiple physical fields.

[0004] 2) In terms of long-distance underwater data transmission, existing solutions face a trade-off between communication speed, distance, and reliability. Traditional cable transmission suffers from severe signal attenuation and bandwidth limitations over long distances and is susceptible to electromagnetic interference. While emerging underwater wireless communication technologies, such as underwater acoustic or underwater optical communication, can provide connectivity in certain specific scenarios, they each have their drawbacks. For applications requiring real-time, high-precision data transmission, especially systems acquiring weak electromagnetic signals, the noise suppression capability and reliability of the transmission link are crucial. Therefore, there is an urgent need for a long-distance wired transmission solution that can adapt to different distance requirements while ensuring high bandwidth and low noise.

[0005] 3) When underwater measurement devices operate in the high-pressure, high-tension environment of the deep sea, their mechanical structure and sealing integrity face severe challenges. Traditional structural designs are often not optimized in terms of shell materials, sealing, and hydrodynamic design. For example, if the sealing structure at the connection between the shell and the cable is not robust enough, leakage or cable pull-out may occur under high pressure and high tensile loads, especially during high-tensile towing or cable retrieval. In addition, non-streamlined designs lead to increased underwater resistance and are prone to entanglement or damage during cable reeling, further reducing the reliability of the system.

[0006] 4) Existing underwater measurement systems have shortcomings in node pose perception and data spatial calibration. Many systems only operate under fixed installation conditions and lack an inertial measurement unit (IMU) rigidly integrated with the measurement node, making it difficult to acquire the attitude angle and relative position information of the measurement node in a timely manner. As a result, measurement data such as acoustic, electric, and magnetic fields usually only carry time tags and lack precise "time-position-attitude" joint labels, making it difficult to construct a spatiotemporal vector field of multiphysics fields. It is also not conducive to analyzing the impact of tow cable morphology changes and platform motion on measurement results, thus limiting the engineering application value and subsequent intelligent processing capabilities of the data. Summary of the Invention

[0007] Existing underwater measurement systems generally suffer from problems such as weak multi-parameter synchronous acquisition capabilities, insufficient reliability of long-distance high-speed data transmission, and inadequate accuracy of node pose sensing. Furthermore, the structural safety and operational reliability of the measurement devices need improvement. This invention addresses these technical problems by proposing an underwater measurement device with multiple advantages: it features a compact and reliably sealed structure, integrates an inertial measurement unit, and supports dual communication modes, making it suitable for cable retrieval and capable of working collaboratively with shape-sensing optical fibers. This device enables multi-node, long-distance synchronous underwater multiphysics field measurement. By jointly acquiring and calibrating the position and attitude information of the measurement nodes, it generates spatiotemporally vectorized environmental observation data, ultimately significantly improving the reliability, data utilization efficiency, and maintainability of long-distance, multi-node environmental observation.

[0008] To achieve the above objectives, the present invention provides a measurement device based on an underwater morphology self-sensing smart cable.

[0009] Preferably, the measuring device includes a measuring box and a platform installed inside the measuring box. The platform integrates a microcontroller, an underwater acoustic sensor, an electric field sensor, a magnetic field sensor, an inertial measurement unit (IMU), and an electro-optical conversion module or a CAN communication module. The measuring device is fixedly connected to a smart cable via high-pressure watertight sealing. The smart cable includes two power supply wires, a pair of CAN bus twisted-pair cables or a communication optical fiber, and a multi-core fiber Bragg grating sensor. The microcontroller is connected to the underwater acoustic sensor, electric field sensor, magnetic field sensor, and the IMU to acquire underwater acoustic signals, electric field signals, magnetic field signals, and the attitude angle and / or position information of the measuring node where the measuring device is located. It is also connected to the CAN communication module or the electro-optical conversion module. The microcontroller is configured to perform correlation marking and coordinate processing on the acquired underwater acoustic, electric field, and magnetic field signals based on the attitude angle and / or position information output by the IMU, upscaling each measurement signal into vectorized measurement data containing time, position, and attitude information. The CAN communication module is connected to the CAN bus. A bus twisted-pair cable is used to transmit the vectorized measurement data to the host computer via the bus; the electro-optical conversion module is connected to the communication optical fiber and is used to convert the electrical signal of the vectorized measurement data into an optical signal and transmit it to the host computer through the communication optical fiber; the outer shell of the measurement box adopts a waterproof and pressure-resistant design, and its shape is streamlined to reduce underwater fluid resistance.

[0010] Preferably, the underwater morphology self-sensing smart cable is an underwater environment detection cable, which includes two power supply wires, a pair of CAN bus twisted-pair cables or a communication optical fiber and a multi-core fiber optic grating sensor. The morphology is sensed by the multi-core fiber optic grating sensor, and the remaining internal power supply wires and communication lines are connected to the measuring device to realize the underwater environment data acquisition and transmission function.

[0011] Preferably, when the total length of the smart cable does not exceed a preset threshold, the microcontroller communicates with the host computer via the CAN bus twisted pair through the CAN communication module; when the cable length exceeds the preset threshold, the microcontroller converts the data into an optical signal through the electro-optical conversion module and transmits it via the communication optical fiber to ensure the reliability of long-distance communication.

[0012] Preferably, the outer shell of the measuring box is made of waterproof and pressure-resistant high-strength titanium alloy. The front and rear ends of the measuring box are designed with a smooth, streamlined structure, allowing the smart cable to transition continuously. The connection between the outer shell and the smart cable is sealed with high-pressure watertight potting compound and covered with a waterproof sealing ring to ensure oil tightness and high tensile strength for long-term underwater operation. The size and shape of the outer shell are adapted to the cable winding and recovery requirements, with a smooth surface and compact structure to avoid tangling or damage during cable winding.

[0013] Preferably, the microcontroller is a microcontroller unit with an analog-to-digital conversion interface and multiple communication interfaces to connect the sensor and the communication module; the underwater acoustic sensor is a hydrophone, whose probe is mounted on the outer shell of the measuring box and fixed by high-pressure water-tight sealing glue; the hydrophone acquires sound wave information based on the piezoelectric effect; the electric field sensor includes a pair of silver chloride electrodes and an electrolyte cavity connected to them; the pair of silver chloride electrodes are both immersed in the electrolyte cavity; the cavity forms ion coupling with external seawater through porous ceramic and is electrically isolated from the titanium alloy shell through an insulating short tube; an O-ring is set between the short tube and the shell to achieve high-pressure sealing; the silver chloride electrodes are electrically connected to the high-impedance front-end circuit of the microcontroller via sealed leads; the magnetic field sensor is a triaxial magnetometer, fixed inside the measuring box away from the power source and magnetic materials, for measuring the ambient magnetic field.

[0014] Preferably, the platform is arranged longitudinally along the axis of the measuring box and coaxial with the axis of the smart cable, located in the geometric center region of the measuring box cavity; the support platform is radially supported and connected to the inner wall of the measuring box by eight radially distributed support columns, so as to keep the platform's center of mass coincident with the longitudinal axis, reduce current-induced vibration, and facilitate cable retraction; the platform is provided with a cable core through-cabin seal facing the smart cable core to guide the channel, for docking with the power supply wire, CAN twisted pair and communication optical fiber and avoiding sharp angle bends.

[0015] Preferably, the support platform is made of non-magnetic material such as plastic with a thickness of 8-12 mm for bearing, and the fastening column is made of titanium alloy to fix the support platform with high strength while reducing interference to the magnetometer.

[0016] Preferably, the microcontroller and sensor are mounted on a support platform and fixed to the support platform by four vibration damping posts. The MCU is connected to other modules by a detachable electrical connector, and its circuit board surface is provided with a moisture-proof and insulating coating.

[0017] Preferably, the inertial measurement unit (IMU) includes a three-axis accelerometer, a three-axis gyroscope, and a three-axis magnetometer; the microcontroller unit (MCU) obtains the attitude information of the measuring device in Euler angles and quaternion form in a preset coordinate system through an attitude calculation algorithm.

[0018] Preferably, the microcontroller unit (MCU) will convert the underwater acoustic, electric, and magnetic field measurement results, which are referenced to the coordinate system of the measurement node body, to a geographic coordinate system or an external coordinate system uniformly defined by the host computer based on the attitude information. The MCU will then package and send the three-dimensional vectorized measurement data containing timestamps, location information, and attitude information to construct the spatiotemporal distribution vector field of the underwater acoustic, electric, and magnetic fields.

[0019] The beneficial effects of this invention are as follows: The measurement box adopts a waterproof, sealed, and pressure-resistant streamlined high-strength titanium alloy shell, internally integrating core components such as a microcontroller (MCU), a hydrophone, an electric field sensor (silver chloride electrode), a magnetic field sensor (triaxial magnetometer), and an inertial measurement unit (IMU). This not only reduces the installation and maintenance costs of multiple boxes but also enables the synchronous acquisition of underwater acoustic, electric, and magnetic field signals with node attitude angles and position information, providing unified hardware support for subsequent processing and obtaining complete observation data. A dual-mode scheme of complementary CAN bus and fiber optic link is adopted, with the microcontroller intelligently switching communication modes based on the total cable length and a preset threshold. In short-distance applications, low-noise, plug-and-play real-time transmission is achieved through CAN bus twisted-pair cables; in long-distance applications, the electro-optical conversion module converts electrical signals into optical signals, which are then transmitted through communication optical fibers to achieve high bandwidth and low-loss transmission, effectively balancing the transmission requirements of different scenarios.

[0020] Designed for extreme deep-sea environments, a streamlined titanium alloy shell reduces underwater drag and towing load, minimizing the risk of cable retrieval. The connection between the measurement box and the cable is encapsulated with high-pressure watertight potting compound and reinforced with mechanical interlocking. Combined with high-pressure oil-tight sealing and a watertight perforated structure, this significantly enhances overall strength and watertightness, ensuring long-term stable operation. Non-magnetic platform materials are selected, and the internal component layout is optimized. Strong magnetic sources and high-current devices are strictly kept away from the sensitive area of ​​the triaxial magnetometer, reducing interference from structural components and cables at the source. This results in more stable and reliable magnetic field measurements and significantly improves the accuracy of weak magnetic field detection. Utilizing real-time node attitude angle and position information acquired by the IMU, underwater acoustic, electric, and magnetic field data are time-aligned and spatially calibrated. This transforms traditional scalar data into vectorized data with time, position, and attitude labels, facilitating the reconstruction of the spatiotemporal distribution of underwater multiphysics fields and enhancing the value of data engineering applications and subsequent intelligent analysis capabilities. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the shape of the measuring box of the present invention and its connection with the cable.

[0022] Figure 2 This is a schematic diagram of the internal platform, sensor, and communication module of the measurement box of the present invention.

[0023] Figure 3 Flowchart of dual-mode communication switching logic. Detailed Implementation

[0024] A measurement device based on an underwater morphology-sensing smart cable is disclosed. The device includes a measurement box and a platform installed within the box. The platform integrates a microcontroller, an underwater acoustic sensor, an electric field sensor, a magnetic field sensor, an inertial measurement unit (IMU), and an electro-optical conversion module or a CAN communication module. The measurement device is fixedly connected to the smart cable using high-pressure watertight encapsulation. The smart cable includes two power supply wires, a pair of CAN bus twisted-pair cables or a communication optical fiber, and a multi-core fiber Bragg grating sensor. The microcontroller is connected to the underwater acoustic sensor, electric field sensor, magnetic field sensor, and IMU to acquire underwater acoustic signals, electric field signals, magnetic field signals, and the attitude angle and / or position information of the measurement node where the measurement device is located. It is also connected to the CAN communication module or the electro-optical conversion module.

[0025] The microcontroller is configured to perform correlation marking and coordinate processing on the acquired underwater acoustic, electric, and magnetic field signals based on the attitude angle and / or position information output by the inertial measurement unit (IMU), thereby upscaling each measurement signal into vectorized measurement data containing time, position, and attitude information. The CAN communication module is connected to the CAN bus twisted-pair cable for transmitting the vectorized measurement data to the host computer via the bus; the electro-optical conversion module is connected to the communication optical fiber for converting the electrical signals of the vectorized measurement data into optical signals and transmitting them to the host computer via the communication optical fiber; the outer shell of the measurement box adopts a waterproof, sealed, and pressure-resistant design, with a streamlined shape to reduce underwater fluid resistance.

[0026] The intelligent cable is an underwater environment monitoring cable. The cable includes two power supply wires, a pair of CAN bus twisted-pair cables or a communication optical fiber, and a multi-core fiber optic grating sensor. The multi-core fiber optic grating sensor senses the shape, and the remaining internal power supply wires and communication lines are connected to the measuring device to realize the underwater environment data acquisition and transmission function.

[0027] When the total length of the smart cable does not exceed a preset threshold, the microcontroller in the measuring device communicates with the host computer via the CAN bus twisted pair through the CAN communication module; when the cable length exceeds the preset threshold, the microcontroller converts the data into an optical signal through the electro-optical conversion module and transmits it via the communication optical fiber to ensure the reliability of long-distance communication.

[0028] The outer shell of the measuring box is made of waterproof and pressure-resistant high-strength titanium alloy. The front and rear ends of the measuring box are designed with a smooth, streamlined structure, allowing the smart cable to transition continuously. The connection between the outer shell and the smart cable is sealed with high-pressure watertight potting compound and covered with a waterproof sealing ring to ensure oil tightness and high tensile strength for long-term underwater operation. The size and shape of the outer shell are adapted to the cable winding and recovery requirements, with a smooth surface and compact structure to avoid tangling or damage during cable winding.

[0029] The microcontroller is a microcontroller unit equipped with an analog-to-digital conversion interface and multiple communication interfaces to connect the sensors and communication modules. The underwater acoustic sensor is a hydrophone, with its probe mounted on the outer shell of the measurement box and fixed by high-pressure water-tight sealing glue. The hydrophone acquires sound wave information based on the piezoelectric effect. The electric field sensor includes a pair of silver chloride electrodes and an electrolyte cavity connected to them. The pair of silver chloride electrodes are immersed in the electrolyte cavity. The cavity forms ion coupling with external seawater through porous ceramic and is electrically isolated from the titanium alloy shell through an insulating short tube. An O-ring is set between the short tube and the shell to achieve high-pressure sealing. The silver chloride electrodes are electrically connected to the high-impedance front-end circuit of the microcontroller via sealed leads. The magnetic field sensor is a triaxial magnetometer, fixed inside the measurement box away from the power source and magnetic materials, for measuring the ambient magnetic field.

[0030] The platform is arranged longitudinally along the axis of the measuring box and coaxial with the axis of the smart cable, located in the geometric center region of the measuring box cavity; the support platform is radially supported and connected to the inner wall of the measuring box by eight radially distributed support columns, so as to keep the platform's center of mass coincident with the longitudinal axis, reduce current-induced vibration, and facilitate cable retraction; the platform is provided with a cable core through-cabin seal facing the smart cable core to guide the channel, for docking with the power supply wire, CAN twisted pair and communication optical fiber and avoiding sharp angle bends.

[0031] The support platform is made of non-magnetic materials such as plastic with a thickness of 8-12 mm for bearing loads, and the fastening column is made of titanium alloy to fix the support platform with high strength while reducing interference with the magnetometer.

[0032] The microcontroller and sensor are mounted on the support platform and fixed to the support platform by four vibration damping rubber columns. The MCU is connected to other modules by a detachable electrical connector, and its circuit board surface is provided with a moisture-proof and insulating coating.

[0033] The inertial measurement unit (IMU) includes a three-axis accelerometer, a three-axis gyroscope, and a three-axis magnetometer; the microcontroller unit (MCU) obtains the attitude information of the measuring device in Euler angles and quaternion form in a preset coordinate system through an attitude calculation algorithm.

[0034] The microcontroller unit (MCU) will convert the underwater acoustic, electric, and magnetic field measurement results, which are referenced to the coordinate system of the measurement node body, to a geographic coordinate system or an external coordinate system uniformly defined by the host computer based on the attitude information. The MCU will then package and send the three-dimensional vectorized measurement data, which includes timestamps, location information, and attitude information, to construct the spatiotemporal distribution vector field of the underwater acoustic, electric, and magnetic fields.

[0035] The measurement device based on an underwater morphology self-sensing smart cable of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Example 1

[0036] This invention discloses a measurement device based on an underwater morphology-sensing smart cable, comprising a smart cable deployed underwater and multiple measurement devices distributed along the cable. Each measurement node is evenly distributed along the cable at approximately 30m intervals, and the multiple measurement nodes are connected via a bus structure. Data from each node is ultimately transmitted via the cable to a host computer on the water surface for centralized monitoring and analysis. The smart cable integrates power supply wires for powering each node, a twisted-pair CAN bus for data communication between nodes, communication optical fibers for long-distance data transmission, and a multi-core fiber optic grating sensor for cable morphology monitoring, enabling self-sensing of the towed cable's spatial morphology.

[0037] The core component of the measuring device is a waterproof and sealed measuring box 1, with a streamlined design resembling a capsule with smooth transitions at both ends of a cylinder to reduce underwater fluid resistance. The outer shell of the measuring box is made of titanium alloy material with good corrosion resistance and pressure resistance, and has been reinforced with pressure resistance to withstand the hydrostatic pressure at a predetermined water depth. The measuring box is integrally sealed and encapsulated using mechanical clamps and high-pressure watertight potting compound 2, and then fixed at a designated location on the cable with an external waterproof sealing ring. During installation, a window is opened on the outer sheath of the cable to expose the internal power supply lines, communication twisted pairs, and optical fiber cores 3, which are connected to the electrical interface of the main platform inside the measuring box. The platform has a high-pressure watertight penetration chamber structure 4 facing the intelligent cable core, guiding the cable core into the measuring box. After connection, waterproof annular sealing rings and potting compound are used to seal the cable opening and the contact points of the high-pressure watertight penetration chamber structure, ensuring that the interface is leak-proof under long-term immersion and has a certain tensile strength, thereby maintaining the overall mechanical strength of the cable.

[0038] The measurement box contains an internal mounting platform for fixing the electronic components and maintaining their relative stability. The platform houses a microcontroller (MCU) module, a power management module, an inertial measurement unit (IMU), a sensor module, and a communication module. The microcontroller module can be a high-performance, low-power microcontroller, such as the STM32 series MCU based on the ARM Cortex core. It has a built-in multi-channel analog-to-digital converter for acquiring analog sensor signals and features a CAN bus interface and a universal serial interface to simultaneously support the connection of the CAN communication module and the electro-optical conversion module. The inertial measurement unit (IMU) is preferably an integrated module combining a three-axis accelerometer and a three-axis gyroscope, communicating via I... 2 The MCU is connected via a C or SPI bus to acquire the attitude angle and / or motion information of the measurement box in real time. The power management module includes a voltage regulator circuit that converts the electrical energy from the cable power supply wires into a stable DC voltage required by each device in the measurement node. All electronic components are connected via PCB traces or wire harnesses, and the PCB surface is coated with waterproof adhesive or potting material after installation to further improve its resistance to humidity and vibration.

[0039] The measurement box integrates three types of sensors: underwater acoustic, electric field, and magnetic field sensors. The underwater acoustic sensor 6 is preferably a high-sensitivity hydrophone, installed at the opening in the housing and fixed with high-pressure water sealant. The hydrophone probe senses sound pressure fluctuations, causing the internal piezoelectric material to deform and generate an output charge. The internal side is connected to the MCU via a transmission line to ensure reliable transmission of underwater acoustic data. The hydrophone output signal is amplified by a low-noise preamplifier and filtered against anti-aliasing before being input to the microcontroller's ADC channel. The electric field sensor 7 uses paired silver chloride electrodes, both immersed in an electrolyte cavity connected to them. This cavity is ion-coupled with external seawater through porous ceramic and electrically isolated from the titanium alloy shell by an insulating short tube. An O-ring is used between the short tube and the shell to achieve a high-pressure seal. The two electrodes are connected to the high-impedance differential front end of the MCU via sealed leads. The MCU measures the potential difference differentially and calculates the electric field strength based on the distance between the two electrodes. The magnetic field sensor 8 is a triaxial digital magnetometer, installed inside the measuring box in an area with low magnetic interference. It maintains a distance of ≥50–80 mm from AC / DC power supplies, inductors, and other magnetic or high-current devices. Titanium is preferred for the fasteners. The magnetometer undergoes soft iron calibration and temperature compensation. The magnetometer is then subjected to I… 2 The C-bus communicates with the MCU to achieve real-time measurement of the underwater three-dimensional magnetic field.

[0040] During operation, the MCU synchronously collects the outputs of underwater acoustic, electric field, and magnetic field sensors, as well as the raw acceleration and angular velocity data of the IMU, according to a preset sampling period. It then uses an attitude calculation algorithm to obtain the attitude angle information of the measurement box in its own or external coordinate system. This attitude information is aligned and packaged with the measurement results of various physical quantities using a unified timestamp, forming vectorized measurement data containing time, position / attitude tags. The vectorized data is uploaded to the host computer via a CAN bus twisted-pair cable or through an electro-optical conversion module and communication fiber optic cable, providing basic data support for subsequent spatiotemporal distribution reconstruction and environmental assessment of multiple nodes and multiple physical fields.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A measurement device based on an underwater morphology self-sensing smart cable, characterized in that, The system includes a measurement box, a smart cable, and functional components integrated within the measurement box. The specific structure and connection relationships are as follows: The outer shell of the measuring box is capsule-shaped and streamlined; the outer shell and the smart cable are fixedly connected by high-pressure watertight potting sealant to form an integrated sealed structure. The measuring box is equipped with a platform, which is arranged longitudinally along the axis of the measuring box and coaxial with the axis of the smart cable. It is fixed to the inner wall of the measuring box by eight radially distributed support columns. The platform is equipped with a cable core penetration seal facing the smart cable core. The platform integrates a microcontroller, an underwater acoustic sensor, an electric field sensor, a magnetic field sensor, an inertial measurement unit (IMU), and a communication module. The smart cable contains two power supply wires, a pair of CAN bus twisted-pair cables or a communication optical fiber, and a multi-core fiber optic grating sensor for sensing the shape. The power supply wires and the communication line are connected to the measuring device through the cable core through-cabin seal. The microcontroller is connected to each sensor, inertial measurement unit (IMU), CAN communication module, and communication module respectively, and is used to acquire the attitude angle and / or position information output by each sensor and the IMU, perform correlation marking and coordinate processing on the measurement signals, and generate vectorized measurement data containing time, position and attitude information. The communication module selects the data transmission method based on the length of the intelligent cable: when the cable length does not exceed a preset threshold, the CAN communication module transmits data through the CAN bus twisted pair; when the cable length exceeds the preset threshold, the electro-optical conversion module converts the electrical signal into an optical signal and transmits it to the host computer through the communication optical fiber.

2. The measuring device based on an underwater morphology self-sensing smart cable according to claim 1, characterized in that, The microcontroller is a microcontroller unit equipped with an analog-to-digital conversion interface and multiple communication interfaces. Its coordinate processing of the measurement signal is as follows: the underwater acoustic, electric field and magnetic field measurement results with reference to the coordinate system of the measurement node body are converted to the geographic coordinate system or the external coordinate system uniformly defined by the host computer based on the IMU attitude information, forming three-dimensional vectorized measurement data and sending it in a package.

3. The measuring device based on an underwater morphology self-sensing smart cable according to claim 1, characterized in that, The outer shell of the measuring box is made of high-strength titanium alloy, and the front and rear ends have a smooth streamlined structure to achieve a continuous transition with the smart cable; a waterproof sealing ring is applied to the connection between the outer shell and the smart cable.

4. The measuring device based on an underwater morphology self-sensing smart cable according to claim 1, characterized in that, The platform is made of non-magnetic plastic material with a thickness of 8-12mm, and the radial support columns are made of titanium alloy. The microcontroller and sensors are fixed to the platform by four vibration damping columns. Each module is connected by a detachable electrical connector, and the surface of the circuit board is covered with a moisture-proof and insulating coating.

5. The measuring device based on an underwater morphology self-sensing smart cable according to claim 1, characterized in that: The underwater acoustic sensor is a hydrophone, whose probe is installed on the outer shell of the measuring box and fixed by high-pressure watertight potting glue, and acquires sound wave information based on the piezoelectric effect. The electric field sensor includes a pair of silver chloride electrodes and an electrolyte cavity. The electrodes are immersed in the cavity. The cavity is ion-coupled with external seawater through porous ceramic. It is electrically isolated from the titanium alloy shell through an insulating short tube. An O-ring is provided between the short tube and the shell to achieve high-pressure sealing. The electrodes are connected to the high-impedance front-end circuit of the microcontroller through sealed leads. The magnetic field sensor is a triaxial magnetometer, which is fixed inside the measuring box in a position away from the power source and magnetic materials. The inertial measurement unit (IMU) integrates a three-axis accelerometer, a three-axis gyroscope, and a three-axis magnetometer. The microcontroller obtains attitude information in Euler angles and quaternion form through attitude calculation algorithms.

6. The measuring device based on an underwater morphology self-sensing smart cable according to claim 1, characterized in that: The underwater morphology self-sensing smart cable is an underwater environment detection cable. Its internal multi-core fiber optic grating sensor is dedicated to sensing its own morphology, the power supply wire provides working power to the measuring device, and the CAN bus twisted pair or communication optical fiber serves as the transmission carrier for the measurement data, together realizing the integrated function of underwater environment data acquisition and transmission.

7. The measuring device based on an underwater morphology self-sensing smart cable according to claim 1, characterized in that: The communication module selects a preset threshold for the transmission mode based on the cable length. The threshold is set according to the maximum effective communication distance of the CAN bus twisted pair. When the cable length exceeds the threshold, a combination of an electro-optical conversion module and a communication optical fiber is used to achieve long-distance data transmission, so as to ensure the integrity and real-time performance of data transmission.

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