Submarine cable three-dimensional route detection system and method based on underwater intelligent aeromagnetism

Abstract

The invention discloses a submarine cable three-dimensional route detection system and method based on underwater intelligent aeromagnetism, and belongs to the technical field of crossing of ocean engineering detection and underwater robot control. According to the system, geomagnetic interference is reduced through a non-metal watertight compartment and double triaxial orthogonal coupling air core coils, the detection efficiency is synchronously improved by combining real-time data acquisition and control, three-dimensional routing and burial depth accurate measurement of submarine cables is realized through multi-dimensional data fusion, and through mechanical structure design, a high-frequency closed-loop control algorithm and a multi-source data fusion technology, the reliability of the system is improved. High-precision synchronous measurement of latitude and longitude coordinates and burial depth parameters of the submarine cable is achieved, the measurement precision reaches the centimeter level, and complete three-dimensional space information support is provided for risk assessment, fault location and intelligent operation and maintenance of the submarine cable.

Description

TECHNICAL FIELD

[0001] The application belongs to the cross field of ocean engineering exploration and underwater robot control, and particularly relates to a submarine cable three-dimensional route detection system and method based on underwater intelligent airborne magnetism. BACKGROUND

[0002] With the development of offshore wind power, cross-sea power transmission and other marine engineering, the safe operation and maintenance of submarine cables are facing great challenges. The existing submarine cable detection technology has three key defects: first, in terms of hardware interference, the traditional magnetic measuring instrument is affected by the geomagnetic field, which is mixed with many interference signals, making it impossible to quickly extract the target signal and seriously affecting the positioning efficiency; second, in terms of control real-time, there is a magnitude difference between the sensor data acquisition frequency and the underwater robot control period, which will cause phase lag in the control system, resulting in tracking path oscillation and significantly reducing the detection efficiency; finally, in terms of data dimension, the current mainstream detection equipment can only provide two-dimensional plane route information, and the key parameter of submarine cable anchor resistance ability evaluation, buried depth data, is completely missing. These problems seriously restrict the accurate detection and maintenance efficiency of submarine cables. SUMMARY

[0003] The purpose of the present application is to overcome the shortcomings of the prior art, and to provide a submarine cable three-dimensional route detection system and method based on underwater intelligent airborne magnetism, to solve the problems of strong interference signals, poor real-time performance and single data dimension in the prior art; the system has the advantages of reducing geomagnetic interference, improving control real-time performance and realizing three-dimensional route detection.

[0004] To achieve the above purpose, the following technical solutions are adopted: A submarine cable three-dimensional route detection system based on underwater intelligent airborne magnetism, comprising a submarine cable autonomous detector and a shore detection station connected by electrical signals. The submarine cable autonomous detector comprises an omnidirectional alternating current magnetic sensor and an autonomous underwater vehicle connected by electrical signals, and the omnidirectional alternating current magnetic sensor is installed on the autonomous underwater vehicle. The omnidirectional alternating current magnetic sensor comprises a non-metallic watertight cabin, a lower computer is installed in the non-metallic watertight cabin, the lower computer is connected by electrical signals with an altimeter, an attitude instrument and a navigation positioning instrument, and the lower computer is connected by electrical signals with two three-axis orthogonal coupled air core coils through a data acquisition card. During the measurement process, the submarine cable is located below the middle position of the two three-axis orthogonal coupled air core coils.

[0005] Further improvements of the present application are as follows: Preferably, the lower computer is connected with the autonomous underwater vehicle through a watertight connector arranged outside the non-metallic watertight cabin.

[0006] Preferably, a satellite communication module is mounted on the outer side wall of the non-metal water-tight cabin, and the satellite communication module is electrically connected with the lower computer.

[0007] Preferably, the non-metal water-tight cabin is made of carbon fiber material.

[0008] Preferably, the three-axis orthogonal coupling air core coil is made of enameled wire and is supported by a rigid support.

[0009] Preferably, the attitude instrument is a three-dimensional attitude instrument.

[0010] Preferably, the altimeter is an acoustic altimeter.

[0011] A detection method of the above-mentioned submarine intelligent aeromagnetic-based submarine cable three-dimensional route detection system, comprising the following steps: S1, placing the submarine cable autonomous detector in water, and starting to search for submarine cable; S2, the lower computer calculates the submarine cable direction by collecting the data of the three-axis orthogonal coupling air core coil, the attitude instrument, the altimeter and the navigation positioning instrument in real time, controls the detector to approach the submarine cable, and accelerates the detection speed when the detector stably travels above the submarine cable; S3, during the route detection process, the lower computer controls the navigation direction of the autonomous underwater vehicle by calculating the azimuth angles θ1 and θ2 of the two three-axis orthogonal coupling air core coils relative to the submarine cable; the two three-axis orthogonal coupling air core coils receive the power frequency magnetic field signals emitted by the submarine cable, calculate the distances d1 and d2 of the two three-axis orthogonal coupling air core coils from the submarine cable, combine the height H0 measured by the altimeter, and obtain the submarine cable burial depth d through geometric calculation; S4, the submarine cable autonomous detector transmits the collected data and the calculation results to the shore detection station.

[0012] Preferably, in S3, the control of the navigation direction of the autonomous underwater vehicle is as follows: When θ1 = θ2, the detector travels in the current direction; When θ1 > θ2, the detector corrects the direction to the side of θ1; When θ1 < θ2, the detector corrects the direction to the side of θ2.

[0013] Preferably, in S3, the power frequency magnetic field signal is 50Hz.

[0014] Compared with the prior art, the present application has the following beneficial effects: The combination of the AC magnetic field generating coils with simple structure is provided by the arrangement of a plurality of mutually coupled coils, the three-axis AC magnetic field fast measurement is realized, the along-cable navigation is realized through the intelligent control of the autonomous underwater vehicle, the measurement time cost is greatly saved, the depth parameter is added on the basis of the traditional two-dimensional longitude and latitude measurement, the three-dimensional longitude and latitude and depth measurement is realized, the submarine cable routing information is enriched, reliable reference information is provided for the maintenance work after the submarine cable fault, and the system has the advantages of reducing geomagnetic interference, improving control real-time performance, and realizing three-dimensional routing detection. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a submarine cable three-dimensional routing detection system based on underwater intelligent navigation magnetism; Figure 2 is an internal structure framework diagram of the submarine cable autonomous detector; Figure 3 is a submarine cable three-dimensional routing detection method flowchart based on underwater intelligent navigation magnetism; Figure 4 is an AUV intelligent control algorithm flowchart; Figure 5 is a submarine cable three-dimensional routing detection lower computer algorithm flowchart.

[0016] In the figure, 1 is an omnidirectional AC magnetic sensor, 2 is an autonomous underwater vehicle, 3 is a non-metal water-tight cabin, 4 is a three-axis orthogonal coupling air core coil, 5 is a data acquisition card, 6 is an attitude instrument, 7 is an altimeter, 8 is a navigation positioning instrument, 9 is a lower computer, 10 is a satellite communication module, 11 is a submarine cable autonomous detector, and 12 is a shore detection station. DETAILED DESCRIPTION

[0017] Hereinafter, the terms "first", "second", "third", "fourth" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined with "first", "second", "third", "fourth" can explicitly or implicitly include one or more of the features.

[0018] The method of shooting provided in the embodiments of the application can be applied to terminal devices such as mobile phones, tablet computers, wearable devices, vehicle-mounted devices, augmented reality (AR) / virtual reality (VR) devices, notebook computers, ultra-mobile personal computers (UMPCs), netbooks, personal digital assistants (PDAs), and the like. The embodiments of the application do not make any limitation on the specific type of the terminal device.

[0019] It is to be understood that the terminology "first", "second", and the like used in the specification and the claims of the application is merely intended to distinguish between similar objects and not necessarily for describing a specific sequential or chronological order. It is to be understood that the use of such terms can be interchanged in order to describe the embodiments of the application herein described in other than the given order. Furthermore, the terms "comprising", "including", "containing", and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, product or apparatus that comprises, includes or contains an item or list of items that does not include all of the recited items can still be deemed to include the recited items.

[0020] In the prior art, the field of submarine cable detection has long been plagued by technical bottlenecks such as limited measurement speed due to large hardware interference, path tracking oscillation caused by control real-time mismatch, and lack of three-dimensional burial depth data. Traditional magnetic sensors are easily disturbed by the geomagnetic field, and the control cycle of underwater robots does not match the data acquisition frequency, resulting in low detection efficiency. Existing equipment can only provide two-dimensional plane information, which cannot meet the needs of submarine cable anchor damage resistance evaluation, and the lack of burial depth data directly affects the accuracy of various instructions during operation.

[0021] Referring to Figure 1 and Figure 2 , the first aspect of the application discloses a submarine cable three-dimensional routing detection system based on underwater intelligent magnetic navigation, comprising a submarine cable autonomous detector 11 and a shore detection station 12 connected by electrical signals. The submarine cable autonomous detector 11 is composed of an omnidirectional alternating current magnetic sensor 1 and an autonomous underwater vehicle 2, and the sensor 1 is installed on the vehicle 2. The sensor 1 contains a non-metal water-tight cabin 3, and a lower computer 9 connected to an altimeter 7, an attitude instrument 6, and a navigation positioning instrument 8 is arranged in the cabin. The lower computer 9 is connected to two three-axis orthogonal coupled air core coils 4 through a data acquisition card 5. During measurement, the submarine cable is located below the middle of the two sensors 4.

[0022] The three-axis orthogonal coupled air core coil 4 is a sensor that combines three-axis orthogonal structure and air core technology, mainly used for high-precision measurement of physical quantities in three-dimensional space. Its core feature is to eliminate inter-axis interference through orthogonal coupling design, and to improve sensitivity and stability by using air core. The three-axis orthogonal coupled air core coil 4 integrates three mutually perpendicular sensitive units (X, Y, Z axes) inside, each unit independently detects the physical quantity in the corresponding direction. The orthogonal design ensures that the measurement of each axis does not interfere with each other, for example, in magnetic field measurement, the magnetic field components in three directions can be obtained simultaneously. The three-axis orthogonal coupled air core coil 4 uses air as the medium, avoiding the saturation effect and hysteresis loss of the iron core.

[0023] In the system, the autonomous underwater vehicle 2 carries the all-directional AC magnetic sensor 1 to cruise underwater. The three-axis orthogonal coupling air core coils 4 are symmetrically arranged to form a detection area, and real-time capture the power frequency magnetic field signal of the submarine cable. The lower computer 9 synchronously processes multi-dimensional data such as magnetic field strength, carrier attitude, navigation height, position coordinates, etc., and calculates the submarine cable azimuth angle through magnetic field vector analysis. When the azimuth deviation is detected, the control algorithm generates a heading correction instruction to drive the autonomous underwater vehicle 2 to stably track along the submarine cable. Combined with the distance between the two three-axis orthogonal coupling air core coils 4 and the altimeter 7 data, the submarine cable burial depth value is solved by using a spatial geometric model to form complete three-dimensional routing information.

[0024] The present application improves the magnetic field detection sensitivity by arranging two three-axis orthogonal coupling air core coils 4, solves the control lag problem through real-time data fusion mechanism, can effectively eliminate the influence of geomagnetic interference on measurement accuracy, realizes millisecond-level synchronization of underwater robot motion control and data acquisition, and accurately obtains the three-dimensional spatial coordinates of the submarine cable.

[0025] In some embodiments of the present application, the lower computer 9 is connected with the autonomous underwater vehicle 2 through a watertight connector arranged outside the non-metal watertight cabin 3. The watertight connector refers to a waterproof sealed electrical connector, which can be realized by a structure of metal shell matched with rubber sealing ring, and its function is to realize physical isolation and signal conduction between the devices inside and outside the cabin. The watertight connector is fixed outside the cabin wall of the non-metal watertight cabin 3, the internal conductive terminal is connected with the circuit board of the lower computer 9 inside the cabin through the cabin-penetrating wire, and the external interface end is connected with the control system of the autonomous underwater vehicle 2 through the waterproof cable. This structure enables the lower computer 9 to receive the navigation state data of the autonomous underwater vehicle 2 in real time, and transmit the magnetic field detection signal to the propulsion system of the autonomous underwater vehicle 2, so as to realize closed-loop control. Since the connector is completely exposed outside the cabin body, the integrity of the cabin body is not damaged by the cabin-penetrating structure. At the same time, through the combination of the external watertight connector and the non-metal cabin 3, the sealing of the equipment is guaranteed, and the secondary interference of the three-axis orthogonal coupling air core coil 4 by the metal material is eliminated, so that the collection accuracy of the power frequency magnetic field signal is guaranteed, and the autonomous underwater vehicle 2 can perform heading correction action according to accurate magnetic field data.

[0026] In some embodiments of the present application, a satellite communication module 10 is mounted on the outer side wall of the non-metal water-tight cabin 3, and the satellite communication module 10 is electrically connected with the lower computer 9. The satellite communication module 10 is fixed to the outer surface of the non-metal water-tight cabin 3, and an electrical connection is established between the satellite communication module 10 and the lower computer 9 in the cabin through a water-tight connector. During the detection operation, the lower computer 9 transmits the magnetic field data collected by the three-axis orthogonal coupled air core coil 4, the navigation attitude data recorded by the attitude instrument 6, and the position coordinates obtained by the navigation positioning instrument 8 to the shore detection station 12 in real time through the satellite communication module 10. Due to the material characteristics of the non-metal water-tight cabin 3, the antenna signal transmission of the satellite communication module 10 will not be affected by the electromagnetic shielding effect of the cabin body, and the cabin structure effectively isolates the physical damage of the communication module 10 caused by the underwater pressure. In the present application, the satellite communication module 10 is integrated on the outside of the non-metal water-tight cabin 3, and a communication link is directly established between the underwater equipment and the shore base, avoiding the reliability risk of the relay link. At the same time, the material of the non-metal cabin 3 ensures the synchronization of data collection and communication signal transmission of the three-axis orthogonal coupled air core coil 4.

[0027] In some embodiments of the present application, the non-metal water-tight cabin 3 is made of carbon fiber material. As a protective shell for the sensor assembly, the carbon fiber material will not produce eddy current effect during the power frequency magnetic field detection process, thereby eliminating the magnetic field distortion interference caused by metal materials. Traditional water-tight cabins are mostly made of aluminum alloy or stainless steel, which has electric conductivity and can absorb the power frequency magnetic field energy of the submarine cable, resulting in attenuation of the sensor signal. Ordinary non-metal materials such as engineering plastics have no electromagnetic interference, but the mechanical strength is insufficient and difficult to withstand underwater pressure. The carbon fiber material solves the contradiction between hardware interference and structural reliability by combining non-conductivity and high strength.

[0028] In some embodiments of the present application, the three-axis orthogonal coupled air core coil 4 is made of enameled wire winding and is supported by a rigid support. The three-axis orthogonal coupled air core coil 4 is formed by enameled wire winding without a magnetic core structure, thereby avoiding the magnetic hysteresis effect and residual magnetism interference introduced by traditional iron core materials. The three axial windings of the three-axis orthogonal coupled air core coil 4 are fixed in mutually perpendicular spatial orientations by the rigid support, thereby ensuring the independence of signal collection in each direction during magnetic field measurement. During measurement, the power frequency magnetic field signal is inducted by the three orthogonal direction coils, and the generated electric signal is transmitted to the lower computer 9 for vector synthesis calculation through the data acquisition card 5.

[0029] In some embodiments of the present application, the attitude instrument 6 is a three-dimensional attitude instrument. During the detection process, the three-dimensional attitude instrument continuously outputs the pitch angle, roll angle and yaw angle data of the submarine cable autonomous detector 11, which are input into the lower computer 9 together with the height from the seabed measured by the altimeter 7 and the position information of the navigation positioning instrument 8. The lower computer 9 fuses multi-dimensional data to eliminate the magnetic field measurement error caused by the change of the carrier attitude, and ensures that the magnetic field signals collected by the two three-axis orthogonal coupled air core coils 4 can accurately reflect the spatial orientation of the submarine cable. During the detection process, the three-dimensional attitude instrument 6 continuously outputs the pitch angle, roll angle and yaw angle data of the submarine cable autonomous detector 11, which are input into the lower computer 9 together with the height from the seabed measured by the altimeter 7 and the position information of the navigation positioning instrument 8. The lower computer 9 fuses multi-dimensional data to eliminate the magnetic field measurement error caused by the change of the carrier attitude, and ensures that the magnetic field signals collected by the two three-axis orthogonal coupled air core coils 4 can accurately reflect the spatial orientation of the submarine cable.

[0030] In some embodiments of the present application, the altimeter 7 is an acoustic altimeter. During the navigation of the submarine cable autonomous detector 11, the acoustic altimeter continuously emits acoustic wave signals to the seabed and receives reflected waves, and calculates the vertical height H0 between the detector and the seabed in real time by calculating the round-trip time difference of the acoustic waves. The height data and the horizontal distances d1 and d2 of the submarine cable measured by the two three-axis orthogonal coupled air core coils 4 are input into the geometric calculation model to solve the burial depth d of the submarine cable through set operation. The detection characteristics of the acoustic altimeter enable it to maintain millimeter-level measurement accuracy in complex seabed topography, avoiding the signal attenuation problem caused by suspended particle scattering of optical sensors. The acoustic altimeter can also work stably in turbid water or insufficient light environment, effectively eliminating the measurement error of traditional pressure sensors caused by ocean current disturbance.

[0031] The present application also discloses a detection method of a submarine cable three-dimensional routing detection system based on underwater intelligent navigation magnetism, comprising the following steps: S1, placing the submarine cable autonomous detector 11 in water and starting to search for the submarine cable; S2, the lower computer 9 calculates the position of the submarine cable by real-time acquisition of the data of the three-axis orthogonal coupled air core coils 4, the attitude instrument 6, the altimeter 7 and the navigation positioning instrument 8, controls the detector to approach the submarine cable, and accelerates the detection speed when the detector is stably running above the submarine cable; S3, during the routing detection process, the lower computer 9 controls the navigation direction of the autonomous underwater vehicle 2 by calculating the azimuth angles θ1 and θ2 of the two three-axis orthogonal coupled air core coils 4 relative to the submarine cable; receives the power frequency magnetic field signals emitted by the submarine cable through the two three-axis orthogonal coupled air core coils 4, calculates the distances d1 and d2 from the submarine cable, and combines the height H0 from the seabed measured by the altimeter 7 to obtain the burial depth d of the submarine cable through geometric calculation; S4, the submarine cable autonomous probe 11 transmits the collected data and calculation results to the onshore detection station 12.

[0032] In the above method, during the measurement process, after the probe enters the working state, the three-axis orthogonal coupled air core coil 4 continuously collects the three-dimensional magnetic field data generated by the submarine cable, and the attitude instrument 6 and the altimeter 7 provide the carrier attitude and the height from the bottom parameters respectively. The lower computer 9 fuses the multi-source sensor data to calculate the azimuth deviation of the submarine cable in real time, generates the navigation control command, makes the autonomous underwater vehicle 2 travel, and makes the omnidirectional alternating magnetic sensor 1 keep above the submarine cable. When the azimuth angle difference of the two three-axis orthogonal coupled air core coils exceeds the threshold value, the control system triggers the heading correction mechanism, adjusts the output of the propeller by comparing the size relationship of θ1 and θ2, and makes the probe travel along the predetermined trajectory stably. After obtaining the distance parameters d1, d2 and H0, the spatial geometric model is used to solve the burial depth of the submarine cable, and finally the information packet containing the three-dimensional coordinates, the burial depth value and the original measurement data is transmitted to the shore-based platform through the communication link. The three-axis orthogonal coupled air core coil 4 of the present application matches the control command generation frequency with the sensor sampling rate, effectively eliminates the phase lag phenomenon, and fuses the distance parameters of the double sensors and the height from the bottom data to construct a three-dimensional spatial positioning model, realizing the online solution of the burial depth value.

[0033] In some specific embodiments, the azimuth angle comparison frequency can be synchronized with the control frequency of the autonomous underwater vehicle 2. The phase lag caused by the difference between data acquisition and control cycle is avoided. Through the synchronous mechanism of real-time azimuth angle comparison and heading correction, the phase lag phenomenon is eliminated. At the same time, based on the direction judgment method of the azimuth angle difference of the double coils, compared with the single coil detection scheme, the position of the submarine cable center line can be more accurately identified.

[0034] In some embodiments of the present application, the power frequency magnetic field signal is 50Hz. In the route detection process, the two three-axis orthogonal coupled air core coils receive the 50Hz power frequency magnetic field signal emitted by the submarine cable, and perform signal filtering and solution based on the fixed frequency characteristics, excluding other frequency band environmental noise interference. By measuring the phase difference and amplitude difference of the signals received by the two sensors, combining the geometric relationship calculation and the distance parameter of the submarine cable, and then combining the altimeter data to deduce the burial depth value. Since 50Hz is the standard frequency of the power system, the signal characteristics are predictable and stable, so that the magnetic field signal solution algorithm can be optimized and designed for fixed frequency points, improving the data processing efficiency.

[0035] The above and other embodiments of the present application will be further described in conjunction with specific examples.

[0036] Example 1 The accompanying drawings are incorporated into the present application to further illustrate the present application. Figure 1 and 2As shown, the application designs a submarine cable three-dimensional route detection system based on underwater intelligent navigation magnetism. It comprises a submarine cable autonomous detector 11 and a shore detection station 12. The submarine cable autonomous detector 11 comprises a full-range AC magnetic sensor 1 and an autonomous underwater vehicle 2. The full-range AC magnetic sensor 1 comprises a non-metal water-tight cabin 3, two three-axis orthogonal coupling air core coils 4, a data acquisition card 5, an attitude instrument 6, an altimeter 7, a navigation positioning instrument 8, a lower computer 9 and a satellite communication module 10.

[0037] The whole full-range AC magnetic sensor 1 is installed on the autonomous underwater vehicle 2 and connected with the autonomous underwater vehicle 2 through water-tight connectors; the full-range AC magnetic sensor 1 can control the moving path of the autonomous underwater vehicle 2.

[0038] The non-metal water-tight cabin 3 is provided with two water-tight connectors on the outer wall; the three-axis orthogonal coupling air core coils 4, the data acquisition card 5, the attitude instrument 6, the altimeter 7, the navigation positioning instrument 8 and the lower computer 9 are fixed in the non-metal water-tight cabin 3 through rigid connection; the satellite communication module 10 is fixed on one of the water-tight connectors on the outer wall of the non-metal water-tight cabin 3 after being water-proofed, and the lower computer 9 is connected with the satellite communication module 10 through a cable and a water-tight connector.

[0039] The three-axis orthogonal coupling air core coils 4 in the non-metal water-tight cabin 3 are connected with the data acquisition card 5 to transmit the collected data to the data acquisition card 5, and the data output end of the data acquisition card 5 is connected with the lower computer 9 through electrical signal.

[0040] The attitude instrument 6, the altimeter 7 and the navigation positioning instrument 8 are connected with the lower computer 9 through electrical signal to input the collected corresponding signal data into the lower computer 9, and the output end of the lower computer 9 is connected with the satellite communication module 10 through electrical signal.

[0041] The non-metal water-tight cabin 3 is made of carbon fiber material; the three-axis orthogonal coupling air core coils 4 are made of enameled wire and supported by rigid supports; the data acquisition card 5 collects three-axis output data of the three-axis orthogonal coupling air core coils 4; the attitude instrument 6 is a three-dimensional attitude instrument and collects attitude data of the submarine cable autonomous detector 11, the submarine cable autonomous detector 11 adjusts its attitude according to the attitude conversion degree to make the three-component data of the AC magnetic field measured by the three-axis orthogonal coupling air core coils 4 always be three-component data of the magnetic field under geographical coordinates; the altimeter 7 is used to measure the real-time vertical height of the submarine cable autonomous detector 11 from the sea floor; the navigation positioning instrument 8 is used to measure the longitude and latitude coordinates of the submarine cable autonomous detector 11; the lower computer 9 is used to receive the storage or output data of the data acquisition card 5, the attitude instrument 6, the altimeter 7 and the navigation positioning instrument 8 and control the navigation path of the autonomous underwater vehicle 2; and the satellite communication module 10 is used to transmit the data processed by the lower computer 9 back to the shore detection station 12.

[0042] Embodiment Two The method for three-dimensional route detection of submarine cable based on underwater intelligent airborne magnetic is carried out by using the above system. The principle of the method is shown in Figure 3 The measuring method comprises the following steps: S1. The non-metal water-tight cabin 3 is installed on the autonomous underwater vehicle 2 through the water-tight connector of the outer wall of the non-metal water-tight cabin 3 to form a submarine cable autonomous detector 11, and the detector is placed in water, and then the measurement is started.

[0043] S2. The detector starts to search for the submarine cable. At this time, the preset speed is slow, the data in the three-axis orthogonal coupled air core coil 4, the attitude instrument 6, the altimeter 7 and the navigation positioning instrument 8 are collected in real time, the position of the submarine cable is calculated, and the detector is controlled by the lower computer to approach the position of the submarine cable. When the detector can stably travel above the submarine cable, the travel speed of the detector is increased.

[0044] S3. The detector performs three-dimensional route detection of the submarine cable.

[0045] S3.1. The detector performs longitude and latitude detection of the submarine cable.

[0046] When the detector can travel along the cable, the travel trajectory of the detector is the longitude and latitude coordinates of the submarine cable. In order to ensure that the detector can travel along the cable, intelligent control is performed on the autonomous underwater vehicle 2 at this time, and the specific steps are as follows: Through calculation, the azimuth angles θ1 and θ2 of the two three-axis orthogonal coupled air core coils 4 relative to the submarine cable are obtained, as shown in Figure 4 When θ1 and θ2 are equal, it indicates that the detector is traveling along the cable; when θ1 is greater than θ2, it indicates that the detector is located on the right side of the submarine cable and should be corrected to the left; when θ1 is less than θ2, it indicates that the detector is located on the left side of the submarine cable and should be corrected to the right. S3.2. The detector performs submarine cable depth detection.

[0047] When the two three-axis orthogonal coupled air core coils 4 in the detector receive the 50Hz power frequency magnetic field signal emitted by the submarine cable, the distances between the two three-axis orthogonal coupled air core coils 4 and the submarine cable are calculated by the inversion formula, which are d1 and d2 respectively. At the same time, the included angle between the connecting line of the two three-axis orthogonal coupled air core coils 4 relative to the submarine cable and the axis of the submarine cable can be obtained, which are θ1 and θ2 respectively. The collected data is transmitted to the lower computer 9 through the data acquisition card 5, and the calculation is performed in the lower computer 9.

[0048] Referring to Figure 5Since the sea cable latitude and longitude detection ensures that the detector must be located directly above the sea cable, based on the included angle between the two three-axis orthogonal coupling air core coils 4 and the sea cable and the distance between the two three-axis orthogonal coupling air core coils 4, the vertical distance H between the detector and the sea cable can be obtained through geometric calculation (Pythagorean theorem) l The height H0 of the detector from the seabed is obtained by the altimeter, and the burial depth d of the sea cable is obtained by difference calculation.

[0049] S4 The detector returns the sea cable three-dimensional route detection data to the detection station When the detector approaches the offshore wind farm, it will float out of the water due to the presence of obstacles.

[0050] After floating out of the water, the path latitude and longitude data and the burial depth data are transmitted back to the shore monitoring station 12 through the satellite communication module, and the shore monitoring station draws a sea cable three-dimensional route image according to the path latitude and longitude and burial depth data.

[0051] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus generate a means for implementing the functions specified in the flow Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1 The functions specified in one flow or multiple flows and / or blocks

[0052] These computer program instructions can also be stored in a computer-readable memory that can direct the computer or other programmable data processing apparatus to work in a specific way, so that the instructions stored in the computer-readable memory produce a product including instruction means, which implements the functions specified in the flow Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1 The functions specified in one flow or multiple flows and / or blocks

[0053] These computer program instructions can also be loaded into a computer or other programmable data processing apparatus, so that a series of operation steps are performed on the computer or other programmable data processing apparatus to produce a computer-implemented process, so that the instructions executed on the computer or other programmable data processing apparatus provide steps for implementing the functions specified in the flow Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1 The functions specified in one flow or multiple flows and / or blocks

[0054] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit it. Although the present application has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the specific embodiments of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the protection scope of the claims of the present application.

Claims

1. An underwater intelligent marine magnetic-based submarine cable three-dimensional routing detection system, characterized in that, The submarine cable autonomous detector (11) and the onshore detection station (12) are electrically connected with each other; The submarine cable autonomous detector (11) comprises a full-range AC magnetic sensor (1) and an autonomous underwater vehicle (2) which are electrically connected with each other, and the full-range AC magnetic sensor (1) is installed on the autonomous underwater vehicle (2); The full-range AC magnetic sensor (1) comprises a non-metal watertight cabin (3) in which a lower computer (9) is installed, the lower computer (9) is electrically connected with an altimeter (7), an attitude instrument (6) and a navigation positioning instrument (8), and the lower computer (9) is electrically connected with two three-axis orthogonal coupled air core coils (4) through a data acquisition card (5); During the measurement, the submarine cable is located below the middle position of the two three-axis orthogonal coupled air core coils (4).

2. The submarine cable 3D routing detection system based on underwater intelligent aeromagnetic surveying according to claim 1, characterized in that, The lower computer (9) is connected with the autonomous underwater vehicle (2) through a watertight connector arranged outside the non-metal watertight cabin (3).

3. The system of claim 1, wherein the system is configured to determine a three-dimensional route of the submarine cable based on the underwater intelligent airborne magnetic survey. A satellite communication module (10) is installed on the outer wall of the non-metal watertight cabin (3), and the satellite communication module (10) is electrically connected with the lower computer (9). ​ 4. The system of claim 1, wherein the system is configured to determine a three-dimensional route of the submarine cable based on the underwater intelligent airborne magnetic survey. The non-metal watertight cabin (3) is made of carbon fiber material.

5. The system of claim 1, wherein the system is configured to determine a three-dimensional route of the submarine cable based on the underwater intelligent airborne magnetic survey. The three-axis orthogonal coupled air core coil (4) is made of enameled wire winding and is supported by a rigid support.

6. The system of claim 1, wherein the system is configured to: The attitude instrument (6) is a three-dimensional attitude instrument.

7. The system of claim 1, wherein the system is configured to determine a three- dimensional route of the submarine cable based on the underwater intelligent airborne magnetic survey. The altimeter (7) is an acoustic altimeter.

8. The method for detecting the submarine cable three-dimensional route detection system based on the underwater intelligent magnetic navigation of claim 1, characterized in that, The method comprises the following steps: S1, placing the submarine cable autonomous detector (11) in water to start searching for the submarine cable; S2, the lower computer (9) calculates the position of the submarine cable by collecting the data of the three-axis orthogonal coupled air core coils (4), the attitude instrument (6), the altimeter (7) and the navigation positioning instrument (8) in real time, controls the detector to approach the submarine cable, and accelerates the detection speed when the detector stably travels above the submarine cable; S3, during the routing detection, the lower computer (9) controls the navigation direction of the autonomous underwater vehicle (2) by calculating the azimuth angles θ1 and θ2 of the two three-axis orthogonal coupled air core coils (4) relative to the submarine cable, receives the power frequency magnetic field signals emitted by the submarine cable through the two three-axis orthogonal coupled air core coils (4), calculates the distances d1 and d2 of the two three-axis orthogonal coupled air core coils (4) from the submarine cable, combines the height H0 measured by the altimeter (7) from the sea floor, and obtains the buried depth d of the submarine cable through geometric calculation; S4, the submarine cable autonomous detector (11) transmits the collected data and the calculation results to the onshore detection station (12).

9. The detection method of the submarine cable three-dimensional routing detection system based on underwater intelligent airborne magnetic according to claim 8, characterized in that, In S3, the control of the navigation direction of the autonomous underwater vehicle (2) is as follows: When θ1 = θ2, the detector travels in the current direction; When θ1 > θ2, the detector corrects the direction to the side of θ1; When θ1 < θ2, the detector corrects the direction to the side of θ2.

10. The method of claim 8, wherein the method further comprises: In S3, the power frequency magnetic field signal is 50 Hz.

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