Submarine cable path tracking method and device based on double-path quantum magnetometer

Abstract

The invention relates to a submarine cable path tracking method and device based on a double-path quantum magnetometer, and the method comprises the steps: measuring a first magnetic field and a second magnetic field of a submarine cable at the same time through two quantum magnetometer probes, and calculating the amplitude of the first magnetic field and the amplitude of the second magnetic field, the phase difference between the first magnetic field and the second magnetic field is obtained; the real-time position of the carrying platform is judged according to the amplitude difference and the phase difference of the first magnetic field and the second magnetic field, then the carrying platform is controlled to the position over the submarine cable in real time, and then path movement of the submarine cable is tracked. The whole detection process is short in time consumption, is slightly influenced by the posture change of the carrying platform, and is suitable for various sea conditions.

Description

Technical Field

[0001] This invention relates to the field of power cable inspection, and in particular to a method and apparatus for tracking submarine cable paths based on a dual-channel quantum magnetometer. The method utilizes two quantum magnetometers to simultaneously measure scalar magnetic field data of submarine cables to track the path of submarine power cables. Background Technology

[0002] Submarine cables are the primary carriers for integrating energy into terrestrial power grids. However, these cables face potential risks of damage from natural factors and human activities. When cable damage occurs, detailed submarine cable route maps provide invaluable reference for locating the fault point. Cable route tracking and monitoring has become an important direction in the field of submarine cable inspection.

[0003] Traditional magnetic detection methods typically utilize vector magnetic field sensors mounted on platforms such as surface vessels, autonomous underwater vehicles (AUVs), and remotely operated underwater vehicles (ROVs), including induction coils and fluxgate magnetometers. A drawback of these sensors is that their measurement accuracy is significantly affected by changes in the attitude of the mounting platform. In high sea states, platform jitter can increase the measurement error of the vector magnetic field sensor, thus impacting the positioning accuracy of submarine cables.

[0004] For quantum magnetometers, the probe orientation has little impact on measurement accuracy and can effectively detect time-varying electromagnetic signals at power frequency. Typical submarine cable path detection schemes using a single-channel quantum magnetometer probe are limited by the number of sensors. To maximize the scalar magnetic field data characteristics, the probe must move radially across the cable at a large tangential angle during detection, resulting in a long detection time.

[0005] This invention proposes a cable path tracking technology based on dual quantum magnetometer probes. It uses two quantum magnetometers to measure the combined magnetic field of the magnetic field generated by the alternating current in the cable and the Earth's magnetic field, thereby detecting the two-dimensional spatial path distribution of the submarine cable. This allows the platform to move along the cable path, reducing detection time loss. Furthermore, the two quantum magnetometers are unaffected by the attitude of the platform and possess high sensitivity and robustness. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a method and apparatus for tracking submarine cable paths based on a dual-channel quantum magnetometer.

[0007] In a first aspect, the present invention provides a method for tracking the path of a submarine cable based on a dual-path quantum magnetometer, which is based on a submarine cable path tracking platform that moves underwater or on the surface along the axial direction of the submarine cable. The platform is equipped with a dual-channel quantum magnetometer and a positioning device. The dual-channel quantum magnetometer includes a first-channel quantum magnetometer probe and a second-channel quantum magnetometer probe, wherein the first-channel quantum magnetometer probe and the second-channel quantum magnetometer probe are set at a fixed distance, and the line connecting their centers is perpendicular to the direction of movement of the platform. The positioning device is used to acquire the position information of the platform. The method includes: The first quantum magnetometer probe and the second quantum magnetometer probe simultaneously measure the first magnetic field and the second magnetic field of the submarine cable, respectively. Based on the first and second magnetic fields of the submarine cable, calculate the amplitude of the first magnetic field, the amplitude of the second magnetic field, and the phase difference between the first and second magnetic fields, respectively. The real-time position of the platform is determined by the amplitude difference and phase difference between the first magnetic field and the second magnetic field. Then, the platform is controlled in real time to be directly above the submarine cable, and the movement of the submarine cable is tracked.

[0008] Preferably, the condition for determining the real-time position of the platform is that the amplitude of the first magnetic field and the amplitude of the second magnetic field are equal and the phase difference is within the range of [135°, 225°].

[0009] Preferably, after controlling the mounting platform to be directly above the submarine cable, it is also necessary to perform position error correction of the mounting platform for a fixed period of time.

[0010] Preferably, the process of correcting the position error of the platform over a fixed time period includes: Obtain the angle between the geomagnetic field direction vector and the sea level at the location of the submarine cable. And the height h between the submarine cable and the sea level; Linear fitting is performed on the distribution coordinate points directly above the submarine cable path measured by the platform after a detection operation, to obtain a fitted line; this fitted line is regarded as the submarine cable path before error correction. Calculate the angle between the projection of the geomagnetic field direction vector onto the sea level and the axial direction of the submarine cable path before error correction.

[0011] According to the included angle The height h and the included angle The position error was calculated. for:

[0012] Based on position error The platform is subjected to position calibration at fixed time intervals.

[0013] Preferably, the linear fitting employs the least squares method.

[0014] Preferably, the first magnetic field and the second magnetic field are the resultant magnetic fields of the time-varying magnetic field generated by the power frequency current signal of the submarine cable in the Earth's magnetic field.

[0015] Preferably, the amplitudes of the first magnetic field and the second magnetic field are obtained by performing Fourier transforms on the first magnetic field and the second magnetic field, respectively.

[0016] Preferably, the horizontal distance between the first quantum magnetometer probe and the second quantum magnetometer probe is greater than the cross-sectional diameter of the submarine cable.

[0017] Preferably, the platform can be manually operated via wired or wireless connection, enhancing the system's flexibility and practicality.

[0018] In a second aspect, the present invention provides a submarine cable path tracking device, comprising: The platform is responsible for underwater or surface movement along the axial direction of the submarine cable. The data processing module is responsible for acquiring the first and second magnetic fields of the submarine cable simultaneously measured by the first quantum magnetometer probe and the second quantum magnetometer probe on the mounting platform. Based on the first and second magnetic fields of the submarine cable, calculate the amplitude of the first magnetic field, the amplitude of the second magnetic field, and the phase difference between the first and second magnetic fields, respectively. The real-time position of the platform is determined by the amplitude difference and phase difference between the first magnetic field and the second magnetic field. Then, the platform is controlled in real time to be directly above the submarine cable to track the movement of the submarine cable path.

[0019] The beneficial effects of the present invention include at least the following: Compared to submarine cable path detection schemes using a single-channel quantum magnetometer probe, this invention employs simultaneous measurements using dual-channel quantum magnetometer probes. Based on the amplitude and phase differences between the two magnetic fields, it determines in real time whether the platform is directly above the cable, allowing the platform to directly track the cable's path along its axis without requiring radial movement across the cable at a large tangential angle. This method avoids the complex motion trajectories used in traditional single-probe schemes to enhance signal characteristics. Instead, it locates the submarine cable and tracks its path along the seabed, significantly improving detection efficiency and drastically reducing the overall detection time. Furthermore, compared to submarine cable path detection schemes using vector magnetic field sensors, this invention's dual-quantum magnetometer probe cable path tracking method is less affected by changes in the platform's attitude, is applicable to various sea conditions, and possesses high sensitivity and robustness.

[0020] This invention uses the equal amplitude and phase difference of the two magnetic fields within the range of [135°, 225°] as a condition to determine whether the platform is directly above the cable, achieving highly sensitive identification of the cable's position. Furthermore, this invention introduces a fixed-time-period position error correction mechanism. The system error y0 is calculated using the geomagnetic field direction angle β, the height h, and the path angle α, and corrected by linearly fitting the measured path points using the least squares method, significantly improving the accuracy and reliability of long-term tracking.

[0021] This invention is not only applicable to fault location, but also to long-term monitoring and mapping of cable paths. By combining a positioning device (such as GPS or an underwater positioning system) with a data processing module, it is possible to reconstruct the two-dimensional distribution of cable paths and correct errors, providing reliable data support for the operation and maintenance of submarine cables. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without exceeding the scope of protection claimed by the present invention.

[0023] Figure 1 A flowchart of a submarine cable path tracking method based on a dual-channel quantum magnetometer is provided for an embodiment of the present invention.

[0024] Figure 2 This is a linear fitting diagram of the distribution coordinates of the submarine cable path directly above the platform measured according to an embodiment of the present invention, where (a) is a top view and (b) is a cross-sectional view. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The working principle of this invention: The dual-channel quantum magnetometer can measure the time-varying magnetic field generated by the power frequency current signal in the AC transmission submarine cable. With the Earth's magnetic field Combined magnetic field The platform is equipped with a first-channel quantum magnetometer probe and a second-channel quantum magnetometer probe installed at fixed intervals. As the platform moves along the path of the submarine cable, the first-channel and second-channel quantum magnetometer probes simultaneously measure two scalar magnetic field data points for the submarine cable, which are represented as follows: , Based on two scalar magnetic field data , The amplitude and phase difference, that is, when the two scalar magnetic field data , When the amplitudes are equal and the phase difference is within the range of [135°, 225°], it is determined that the mounting platform is moving directly above the submarine cable, that is, the mounting platform is tracking the path of the submarine cable, and thus the two-dimensional planar path distribution curve of the submarine cable is obtained.

[0027] Furthermore, this embodiment provides a submarine cable path tracking method based on a dual-channel quantum magnetometer, applicable to maintenance tracking methods. It is based on a submarine cable path tracking platform that moves underwater or on the surface along the axial direction of the submarine cable. The platform is equipped with a dual-channel quantum magnetometer and a positioning device. The dual-channel quantum magnetometer includes a first-channel quantum magnetometer probe and a second-channel quantum magnetometer probe, wherein the first-channel and second-channel quantum magnetometer probes are set at a fixed distance, and the line connecting their centers is perpendicular to the movement direction of the platform.

[0028] The dual-channel quantum magnetometer is used to measure the magnetic field data of the submarine cable; the positioning device is used to obtain the location information of the mounting platform and the path of the submarine cable.

[0029] For example, the horizontal distance between the first and second quantum magnetometer probes is greater than the cross-sectional diameter of the submarine cable, ensuring that the two probes are positioned on opposite sides of the cable during tracking, which is beneficial for signal comparison and position determination. Thus, when the platform is positioned directly above the submarine cable to track its path, the first and second quantum magnetometer probes are located on the left and right sides of the submarine cable, respectively.

[0030] According to one embodiment, the platform is an underwater robot that can be manually controlled via a wired connection and can move in seawater.

[0031] Specifically, see Appendix Figure 1 A method for tracking the path of submarine cables based on a dual-channel quantum magnetometer includes: Step S1: Deploy the platform equipped with a dual-channel quantum magnetometer into the seawater near the submarine cable. The first-channel quantum magnetometer probe and the second-channel quantum magnetometer probe simultaneously measure the first and second magnetic fields of the submarine cable, respectively.

[0032] According to some embodiments, both the first magnetic field and the second magnetic field are time-varying magnetic fields generated by the power frequency current signal of the submarine cable. With the Earth's magnetic field Combined magnetic field .

[0033] Step S2: Calculate the amplitude of the first magnetic field, the amplitude of the second magnetic field, and the phase difference between the first magnetic field and the second magnetic field based on the first magnetic field and the second magnetic field of the submarine cable, respectively. According to some embodiments, the amplitude of the first magnetic field and the amplitude of the second magnetic field are obtained by performing Fourier transforms on the first magnetic field and the second magnetic field, respectively.

[0034] Step S3: Determine the real-time position of the mounting platform by the amplitude difference and phase difference between the first magnetic field and the second magnetic field, then control the mounting platform to be directly above the submarine cable in real time, and then track the movement of the submarine cable path.

[0035] According to some embodiments, the condition for determining the real-time position of the platform is that the amplitude of the first magnetic field and the amplitude of the second magnetic field are equal and the phase difference is within the range of [135°, 225°], preferably 180°.

[0036] For example, determining the real-time position of the platform by the amplitude difference and phase difference between the first magnetic field and the second magnetic field specifically involves: According to some embodiments, when the amplitude of the first magnetic field is equal to the amplitude of the second magnetic field and the phase difference is within the range of [135°, 225°], it is determined that the platform is located directly above the submarine cable, and the first and second quantum magnetometer probes are located on the left and right sides of the submarine cable, respectively, tracking the movement of the submarine cable path. Specifically, the position of the first quantum magnetometer probe is defined as the left side of the submarine cable; the position of the second quantum magnetometer probe is defined as the right side of the submarine cable.

[0037] According to some embodiments, when the amplitudes of the first and second magnetic fields are not equal and their phase difference is within the range of [135°, 225°], it is determined that the platform is deviating from directly above the submarine cable and the first and second quantum magnetometer probes are located on the left and right sides of the submarine cable, respectively. Specifically, when the amplitude of the first magnetic field is greater than the amplitude of the second magnetic field and their phase difference is within the range of [135°, 225°], it is determined that the platform is biased towards the left side of the submarine cable, with the first quantum magnetometer probe on the left side and the second quantum magnetometer probe on the right side. The platform is then manually moved to the right side of the submarine cable until the amplitudes of the first and second magnetic fields are equal and their phase difference is within the range of [135°, 225°] (preferably 180°). At this point, the platform returns to directly above the submarine cable and tracks its path. When the amplitude of the first magnetic field is less than the amplitude of the second magnetic field and the phase difference is within the range of [135°, 225°], it is determined that the platform is biased to the right of the submarine cable, and the first quantum magnetometer probe is on the left of the submarine cable and the second quantum magnetometer probe is on the right of the submarine cable. The platform is then manually moved to the left of the submarine cable until the amplitudes of the first and second magnetic fields are equal and the phase difference is within the range of [135°, 225°] (preferably 180°). The platform then returns to directly above the submarine cable to track its path.

[0038] According to some embodiments, when the amplitudes of the first and second magnetic fields are not equal and their phase difference is not within the range of [135°, 225°], it is determined that the platform is deviating from directly above the submarine cable and that both the first and second quantum magnetometer probes are located on the same side of the submarine cable. Specifically, when the amplitude of the first magnetic field is greater than the amplitude of the second magnetic field and their phase difference is not within the range of [135°, 225°], it is determined that the platform is biased towards the left side of the submarine cable and that both the first and second quantum magnetometer probes are located on the left side of the submarine cable. The platform is then manually moved to the right side of the submarine cable until the amplitudes of the first and second magnetic fields are equal and their phase difference is within the range of [135°, 225°] (preferably 180°). At this point, the platform returns to directly above the submarine cable and tracks its path. When the amplitude of the first magnetic field is less than the amplitude of the second magnetic field and the phase difference is not within the range of [135°, 225°], it is determined that the platform is biased to the right of the submarine cable and both the first and second quantum magnetometer probes are located on the right side of the submarine cable. The platform is then manually moved to the left side of the submarine cable until the amplitudes of the first and second magnetic fields are equal and the phase difference is within the range of [135°, 225°] (preferably 180°). The platform then returns to directly above the submarine cable to track its path.

[0039] According to some embodiments, when the amplitude of the first magnetic field and the amplitude of the second magnetic field are equal and the phase difference is within the range of [135°, 225°], it is determined that the mounting platform is located directly above the submarine cable and tracks the movement of the submarine cable path.

[0040] In one implementation, after controlling the mounting platform to be directly above the submarine cable in step S3, it is also necessary to perform position error correction of the mounting platform for a fixed time period.

[0041] Specifically, the process of correcting the position error of the platform over a fixed time period includes: The direction of the geomagnetic field in the actual submarine cable area was obtained by measuring the geomagnetic diurnal variation station, thus obtaining the angle between the geomagnetic field direction vector at the location of the submarine cable and the sea level. (e.g., included angle) β (45°), and calculate the angle between the projection of the geomagnetic field direction vector onto the sea level and the axial direction of the submarine cable path before error correction. And the height h between the submarine cable and the sea level; According to some embodiments, a Cartesian coordinate system is established with the submarine cable as the x-axis. Let the coordinates of point Q (0, y, h) be the location of the platform above the submarine cable at a certain moment. The time-varying magnetic field generated by the power frequency current signal in the submarine cable at point Q... for: Equation (1) Time-varying magnetic field In the geomagnetic field The projected magnetic field B is: Equation (2) in, The vacuum permeability is 4π × 10⁻⁶. -7 H / m , I It is the current in the submarine cable.

[0042] (2) Perform linear fitting on the distribution coordinate points of the position directly above the submarine cable path measured by the platform after a detection operation to obtain the fitting line; regard the fitting line as the submarine cable path before error correction. For example, the linear fitting uses the least squares method.

[0043] Figure 2 This is a linear fitting graph of the distribution coordinates of the positions directly above the submarine cable path measured by a platform according to an embodiment of the present invention, wherein... Figure 2 (a) is a top-down view. Figure 2 (b) is the cross-sectional view.

[0044] (3) Based on the included angle The height h and the included angle The position error was calculated. for: Equation (3) (4) Based on position error The platform is subjected to position calibration at fixed time intervals.

[0045] Thus, when the determined position of the mounting platform directly above the path of the submarine cable is (0, y1, h1), the corresponding actual coordinates of the submarine cable are (0, y1+y0, 0).

[0046] The embodiments of the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, any changes or modifications made by those skilled in the art based on the ideas of the present invention, its specific implementation methods, and its application scope, are all within the scope of protection of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for tracking the path of a submarine cable based on a dual-channel quantum magnetometer, wherein the method is based on a submarine cable path tracking platform, the platform moving underwater or on the surface along the axial direction of the submarine cable; The platform is equipped with a dual-channel quantum magnetometer and a positioning device. The dual-channel quantum magnetometer includes a first-channel quantum magnetometer probe and a second-channel quantum magnetometer probe, wherein the first-channel quantum magnetometer probe and the second-channel quantum magnetometer probe are set at a fixed distance, and the line connecting their centers is perpendicular to the direction of movement of the platform. The positioning device is used to acquire the position information of the platform. Its features are, The method includes: The first quantum magnetometer probe and the second quantum magnetometer probe simultaneously measure the first magnetic field and the second magnetic field of the submarine cable, respectively. Based on the first and second magnetic fields of the submarine cable, calculate the amplitude of the first magnetic field, the amplitude of the second magnetic field, and the phase difference between the first and second magnetic fields, respectively. The real-time position of the platform is determined by the amplitude difference and phase difference between the first magnetic field and the second magnetic field. Then, the platform is controlled in real time to be directly above the submarine cable, and the movement of the submarine cable is tracked.

2. The method according to claim 1, characterized in that, The condition for determining the real-time position of the platform is that the amplitude of the first magnetic field and the amplitude of the second magnetic field are equal and the phase difference is within the range of [135°, 225°].

3. The method according to claim 1, characterized in that, After controlling the mounting platform to be directly above the submarine cable, it is also necessary to perform position error correction on the mounting platform over a fixed period of time.

4. The method according to claim 3, characterized in that, The process of correcting the position error of the platform over a fixed time period includes: Obtain the angle between the geomagnetic field direction vector and the sea level at the location of the submarine cable. And the height h between the submarine cable and the sea level; Linear fitting is performed on the distribution coordinate points directly above the submarine cable path measured by the platform after a detection operation, to obtain a fitted line; this fitted line is regarded as the submarine cable path before error correction. Calculate the angle between the projection of the geomagnetic field direction vector onto the sea level and the axial direction of the submarine cable path before error correction. According to the included angle The height h and the included angle The position error was calculated. for: Based on position error The platform is subjected to position calibration at fixed time intervals.

5. The method according to claim 4, characterized in that, The linear fitting was performed using the least squares method.

6. The method according to claim 1, characterized in that, The first magnetic field and the second magnetic field are the resultant magnetic fields of the Earth's magnetic field generated by the power frequency current signal of the submarine cable.

7. The method according to claim 1, characterized in that, The amplitudes of the first magnetic field and the second magnetic field are obtained by performing Fourier transforms on the first magnetic field and the second magnetic field, respectively.

8. The method according to claim 1, characterized in that, The horizontal distance between the first quantum magnetometer probe and the second quantum magnetometer probe is greater than the cross-sectional diameter of the submarine cable.

9. The method according to claim 1, characterized in that, The platform can be manually operated via wired or wireless connection.

10. A submarine cable path tracking device for implementing the method of any one of claims 1-9, characterized in that, include: The platform is responsible for underwater or surface movement along the axial direction of the submarine cable. The data processing module is responsible for acquiring the first and second magnetic fields of the submarine cable simultaneously measured by the first quantum magnetometer probe and the second quantum magnetometer probe on the mounting platform. Based on the first and second magnetic fields of the submarine cable, calculate the amplitude of the first magnetic field, the amplitude of the second magnetic field, and the phase difference between the first and second magnetic fields, respectively. The real-time position of the platform is determined by the amplitude difference and phase difference between the first magnetic field and the second magnetic field. Then, the platform is controlled in real time to be directly above the submarine cable to track the movement of the submarine cable path.

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