Submarine cable searching and locating device and method

Abstract

The present invention relates to a submarine cable search and positioning device and method, which includes a hammer-shaped detector composed of a first detection rod, a second detection rod, a third detection rod and a fourth detection rod, a signal acquisition and control device and a data analysis platform, wherein the first, second and third detection rods are all position detection rods, have the same structure and are vertically equidistantly distributed in sequence, and the fourth detection rod is horizontally arranged beside the third detection rod and forms a 90° angle with the third detection rod; the hammer-shaped detector and the signal acquisition and control device are carried on an underwater robot for water measurement, and after initially detecting the signal of the submarine cable, the vertical and horizontal relative distances between the hammer-shaped detector and the submarine cable are first calculated according to the induced electromotive force of the position detection rod, and then the route deflection angle between the hammer-shaped detector and the submarine cable is calculated through the fourth detection rod and the third detection rod, thereby determining the unique position coordinates of the submarine cable. The device and method can not only quickly and accurately determine the position of the submarine cable, but also have a simple structure, are easy to implement, and have low requirements for subsequent signal processing.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronics, and in particular relates to a submarine cable searching and locating device and method. Background Art

[0002] As people continue to explore marine resources, submarine cables (including submarine cables and submarine optical cables) have gradually become the main means of cross-sea communications and offshore operations and are widely used. In order to prevent and avoid unknown factors at sea (such as anchors hooking submarine cables, construction of offshore engineering projects, etc.) from damaging submarine cables and affecting optical cable communications and offshore power supply, accurate detection of submarine cable routes and buried depths is very necessary. Current detection methods include AC magnetic field detection, absolute magnetic field detection, metal detection, and AC carrier detection. The AC carrier method is an effective magnetic detection method based on the electromagnetic properties of submarine cables. The basic principle is that when AC current of a specific frequency and power is passed through the submarine cable, the submarine cable will generate an electromagnetic field that spreads to the surrounding space. Using a special sensor to receive this electromagnetic wave signal at an appropriate distance and process and analyze it, the location and route information of the submarine cable can be obtained. The magnetic detection rod composed of a copper coil and a magnetic core is a more practical sensor based on the AC magnetic field detection method. However, in order to obtain reliable information on the route, location, and buried depth of the submarine cable, the coil probe needs to be combined in a suitable way. Among them, the more representative coil probe combination scheme is the dual three-dimensional magnetic probe array based on the underwater robot - the array is composed of two three-dimensional probe arrays, and each three-dimensional probe array is composed of three mutually orthogonal identical probes. The route of the submarine cable and the relative position relationship of the detection array are judged according to the positive and negative relationship of the magnetic induction intensity measured simultaneously on different coils, and the buried depth data of the submarine cable is calculated by the ratio of the induced electromotive force measured on different coils. However, the dual three-dimensional magnetic probe array requires six probes of the same size and has a complex structure. And when judging the relative position of the submarine cable, the positive and negative relationship of the induced electromotive force of each probe at the same time is needed, requiring the subsequent circuit to process at least six signals simultaneously to ensure the accuracy of the submarine cable route judgment. Therefore, this mode has more stringent requirements for subsequent signal processing. Summary of the invention

[0003] The object of the present invention is to provide a submarine cable searching and locating device and method, which can not only quickly and accurately determine the position of the submarine cable, but also has a simple structure, is easy to implement, and has low requirements for subsequent signal processing.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a submarine cable searching and locating device, comprising a hammer-shaped detector composed of a first detection rod, a second detection rod, a third detection rod and a fourth detection rod, a signal acquisition and control device and a data analysis platform, wherein the first detection rod, the second detection rod and the third detection rod are all position detection rods, have the same structure and are vertically equidistantly distributed in sequence, and the fourth detection rod is laterally arranged beside the third detection rod and forms an angle of 90° with the third detection rod; the hammer-shaped detector and the signal acquisition and control device are carried on an underwater robot for underwater measurement, and after initially detecting the signal of the submarine cable, the vertical and horizontal relative distances between the hammer-shaped detector and the submarine cable are first calculated according to the induced electromotive force of the position detection rod, and then the route deviation angle between the hammer-shaped detector and the submarine cable is calculated through the fourth detection rod and the third detection rod, so as to determine the unique position coordinates of the submarine cable.

[0005] Furthermore, the first detection rod, the second detection rod, the third detection rod and the fourth detection rod are all magnetic induction coils, and the four magnetic induction coils form a hammer-shaped sensor array to perform magnetic signal detection.

[0006] Furthermore, the signal acquisition and control device includes a signal conditioning circuit, a data acquisition module and a central control module. The hammer-shaped detector is connected to the central control module via the signal conditioning circuit, the data acquisition module and the central control module in sequence, and the central control module communicates data with the upper data analysis platform.

[0007] Furthermore, the signal conditioning circuit includes an amplifier circuit based on ADA4004 and a filter circuit based on ADA4625, which are used to perform analog signal conditioning to achieve small signal amplification and 30Hz-70Hz bandpass filtering; the data acquisition module includes an AD7192 analog-to-digital converter, an SPI interface circuit and a power supply circuit, and the SPI interface circuit is used to communicate with the central control module; the central control module includes a control circuit with STM32H750XBH6 as the central processor, a button circuit, an Ethernet circuit, a CH340 interface circuit, an LED light and buzzer group and a SWD download and debugging circuit, and the SWD download and debugging circuit is used to communicate data with the data analysis platform.

[0008] The present invention also provides a method for searching and locating submarine cables based on the above device, comprising the following steps:

[0009] Step S1, controlling the underwater robot to move in the direction where the submarine cable may exist, until the induced electromotive force of the fourth detection rod appears, indicating that the submarine cable is approached; since the first, second and third detection rods are all below the fourth detection rod, all detection rods can detect the induced electromotive force at this time;

[0010] Step S2, obtaining the induced electromotive force amplitudes of the first, second and third detection rods, and calculating the horizontal spacing and vertical spacing between the submarine cable and the second detection rod;

[0011] Step S3, the underwater robot drives the hammer-shaped detector to rotate horizontally until the effective value of the induced electromotive force of the fourth detection rod reaches the maximum value of one rotation. At this time, the fourth detection rod is perpendicular to the routing direction of the submarine cable, thereby determining the routing direction of the submarine cable;

[0012] Step S4, using the submarine cable route obtained in step S3, converting the spacing calculated in step S2 into two locations where the submarine cable may exist;

[0013] Step S5: According to the instantaneous positive and negative relationship between the induced electromotive force of the fourth detection rod and the third detection rod, the direction in which the magnetic lines of force generated by the submarine cable magnetic field pass through the fourth detection rod is obtained, thereby determining a unique submarine cable position point.

[0014] Furthermore, the step S2 comprises the following steps:

[0015] Step S21, obtaining the induced electromotive force amplitudes of the first, second and third detection rods;

[0016] Set the horizontal angle between a single probe rod and the submarine cable to The x-axis component of the magnetic induction intensity at the center of the probe rod, that is, the effective magnetic induction intensity component of the probe rod is B x , the horizontal distance between the probe rod and the submarine cable is x', and the vertical distance is y', then the induced electromotive force of the probe rod is:

[0017]

[0018] Therefore, the induced electromotive force of the first detection rod, the second detection rod and the third detection rod is as follows:

[0019]

[0020] in, y1, y2, y3 are the vertical distances between the submarine cable and the first, second, and third detection rods, respectively, and x is the horizontal distance between the submarine cable and the center of the hammer-shaped detector;

[0021] Step S22: Calculate the vertical distance y between the submarine cable and the center of the hammer detector;

[0022] Assume that the center of the hammer-shaped detector falls on the center of the second detection rod, so y=y2; set the ratio of the induced electromotive force of the second detection rod to the third detection rod to be a, and the ratio of the induced electromotive force of the second detection rod to the first detection rod to be b, then the ratio equation group of the induced electromotive force is:

[0023]

[0024] According to the positional relationship between the submarine cable and each detection rod, we get:

[0025]

[0026] Wherein, L represents the distance between the center of the first detection rod and the center of the second detection rod, or the distance between the center of the second detection rod and the center of the third detection rod;

[0027] Combining the above equations, we get:

[0028]

[0029] Solve to get the vertical distance y between the submarine cable and the second detection rod:

[0030]

[0031] Substituting the ratio of the induced electromotive force of a and b, we get:

[0032]

[0033] Step S23: Calculate the horizontal distance x between the submarine cable and the hammer detector;

[0034] Add the two equations in the ratio equation group (1) of the induced electromotive force and substitute equation group (2) into it to obtain:

[0035]

[0036] Substitute the vertical spacing y calculated by formula (5) into formula (6) to calculate the horizontal spacing x:

[0037]

[0038] Furthermore, if the center of the hammer detector is directly above the submarine cable, x = 0, the induced electromotive force of the three position detection rods is zero, and the induced electromotive force cannot be used to calculate the position of the submarine cable. At this time, the position of the submarine cable is determined by the inclined navigation method:

[0039] Tilt the hammer detector 45° in the vertical direction of the submarine cable route, keep the tilt angle and continue to move the hammer detector horizontally in this direction, and constantly monitor the induced electromotive force and moving distance of the third and fourth detection rods; when the induced electromotive force of the third or fourth detection rod drops to 0 during the movement, stop moving the hammer detector;

[0040] According to the characteristics of the magnetic force lines of the submarine cable, at this time, one of the third or fourth detection rods is in the same direction as the magnetic force lines, and the magnetic force lines contribute the most to the generation of its induced electromotive force, and the other is perpendicular to the direction of the magnetic force lines, and the magnetic force lines do not pass through the detection rod, and no induced electromotive force is generated. At this time, the vertical distance between the hammer detector and the submarine cable is equal to the horizontal distance, that is, y = x, where x is equal to the horizontal distance moved by the hammer detector after tilting;

[0041] According to the route direction of the submarine cable, two possible locations of the submarine cable are determined; then, the relative position of the submarine cable is determined according to the instantaneous positive and negative relationship of the induced electromotive force on the third and fourth detection rods to determine the unique location coordinates of the submarine cable.

[0042] Further, in step S5, it is assumed that the induced electromotive force ε4 generated by the magnetic force lines generated by the submarine cable passing through the fourth detection rod from right to left is positive, and the induced electromotive force ε3 generated by the magnetic force lines generated by the submarine cable passing through the third detection rod from top to bottom is negative; from the positional relationship between the magnetic force lines of the submarine cable and the detector, it can be known that: by observing the positive and negative relationship between the induced electromotive force on the third and fourth detection rods at a certain moment, the direction in which the magnetic force lines of the submarine cable pass through the coil is inferred, and the relative position of the submarine cable is determined by combining the properties of the direction of the magnetic force lines of the submarine cable and the horizontal relative distance x, and taking the instantaneous product of the induced electromotive force:

[0043] When ε3·ε4>0, the submarine cable is on the right side of the hammer detector;

[0044] When ε3·ε4<0, the submarine cable is on the left side of the hammer detector.

[0045] Compared with the prior art, the present invention has the following beneficial effects: the present invention can complete the detection of the submarine cable route and the horizontal and vertical spacing between the submarine cable and the detector through the four detection rods in the hammer-shaped detector, so as to quickly and accurately determine the position of the submarine cable. Due to the structural characteristics of the detection array, the device does not need to first determine the route direction of the submarine cable within the detection range, and the vertical distance and the vertical distance between the detector and the submarine cable can be directly obtained at any position. The route deflection calculation results of the third and fourth detection rods are then used to provide direction guidance for the distance to determine the coordinates of the submarine cable. And because only the magnitude relationship of the induced electromotive force of the detection rods at two positions is needed to determine the relative position of the submarine cable, the present invention does not need to perform synchronous sampling when the detector is stationary, which effectively reduces the pressure on the subsequent circuit. In the hammer-shaped detector of the present invention, the distance between the three detection rods is adjustable, and the reasonable design of the interval can not only avoid the magnetic field generated by the detection rod itself during the detection process from interfering with other detection rods, but also can flexibly adjust its resolution according to the actual environment. Therefore, the present invention has strong practicality and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1It is a structural schematic diagram of a hammer-shaped detector in an embodiment of the present invention;

[0047] Figure 2 Schematic diagram of the angle between a single detection rod and a submarine cable in an embodiment of the present invention;

[0048] Figure 3 It is a schematic diagram of a hammer-shaped detector determining the position of a submarine cable by using an inclined navigation method in an embodiment of the present invention;

[0049] Figure 4 It is a schematic diagram of a hammer-shaped detector according to an embodiment of the present invention determining the position of a submarine cable by distance calculation after determining the routing direction of the submarine cable;

[0050] Figure 5 It is a schematic diagram of the hammer-shaped detector in the embodiment of the present invention judging the left-right relationship of the submarine cable through the third and fourth probes;

[0051] Figure 6 It is a schematic diagram of a detection process of carrying a hammer-shaped detector to detect a submarine cable route in an embodiment of the present invention;

[0052] Figure 7 This is a schematic diagram of the structure of a power module in an embodiment of the present invention;

[0053] Figure 8 FIG. 4 is a schematic diagram of a device architecture according to an embodiment of the present invention.

[0054] In the figure: 1. first probe; 2. second probe; 3. third probe; 4. fourth probe; 5. seabed; 6. submarine cable; 7. distribution of magnetic field lines around the submarine cable; 8. possible location points of the submarine cable; 9. routing direction of the submarine cable; 10. horizontal component of the magnetic vector; 11. vertical component of the magnetic vector. DETAILED DESCRIPTION

[0055] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0056] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0057] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0058] like Figure 1 , 8 As shown, this embodiment provides a submarine cable searching and locating device, comprising a hammer-shaped detector consisting of a first detection rod, a second detection rod, a third detection rod and a fourth detection rod, a signal acquisition and control device and a data analysis platform, wherein the first detection rod, the second detection rod and the third detection rod are all position detection rods, have the same structure and are vertically equidistantly distributed in sequence, and the fourth detection rod is laterally arranged beside the third detection rod and forms an angle of 90° with the third detection rod; the hammer-shaped detector and the signal acquisition and control device are carried on an underwater robot for in-water measurement, and after initially detecting the signal of the submarine cable, the vertical and horizontal relative distances between the hammer-shaped detector and the submarine cable are first calculated based on the induced electromotive force of the position detection rod, and then the route deviation angle between the hammer-shaped detector and the submarine cable is calculated through the fourth detection rod and the third detection rod, thereby determining the unique position coordinates of the submarine cable.

[0059] In this embodiment, the first detection rod, the second detection rod, the third detection rod and the fourth detection rod are all magnetic induction coils, and the four magnetic induction coils form a hammer-shaped sensor array to perform magnetic signal detection.

[0060] like Figure 8 As shown, the signal acquisition and control device includes a signal conditioning circuit, a data acquisition module and a central control module. The hammer-shaped detector is connected to the central control module via the signal conditioning circuit, the data acquisition module and the central control module in sequence, and the central control module communicates data with the upper data analysis platform.

[0061] The central control module mainly realizes the data acquisition and uploading functions, including adjusting the amplification gain of the acquisition circuit, digital filtering, calculating the original signal size (because the amplification circuit is adaptive), capturing the voltage peak, etc. The relevant calculation and analysis functions are implemented on the data analysis platform, because compared with stm32, the data analysis platform is based on computers and has better processing performance. In addition, the data analysis platform is not located on the robot but on the surface ship, which is convenient for users to observe signal changes and search for guidance.

[0062] In this embodiment, the signal conditioning circuit includes an amplifier circuit based on ADA4004 and a filter circuit based on ADA4625, which are used to perform analog signal conditioning, realize small signal amplification, and 30Hz-70Hz bandpass filtering. The data acquisition module includes an AD7192 analog-to-digital converter, an SPI interface circuit and a power supply circuit, and the SPI interface circuit is used to communicate with the central control module. The central control module includes a control circuit with STM32H750XBH6 as the central processor, a key circuit, an Ethernet circuit, a CH340 interface circuit, an LED light and a buzzer group, and a SWD download and debugging circuit, and the SWD download and debugging circuit is used to communicate data with the data analysis platform. The central control module obtains the signal collected by the signal processing layer through the SPI communication method, completes data preprocessing such as digital filtering, FFT spectrum analysis, amplitude extraction, and then uploads it to the data analysis platform. The data analysis platform is designed using LabView to implement the above-mentioned submarine cable positioning algorithm, as well as necessary data processing, storage, playback and other functions.

[0063] The signal conditioning circuit based on ADA4004-4 and ADA4625-1 designed in this embodiment has the function of amplifying multi-channel tiny signals and performing 30HZ-70HZ passband filtering. At the same time, the AD sampling module designed based on AD7192 has 24-bit AD sampling accuracy and supports simultaneous acquisition of four-channel signals, meeting the requirements of the hammer detection array for long-distance submarine cable magnetic signal detection.

[0064] The central control module designed based on STM32H750XBH6 and the human-computer interaction and data analysis platform designed based on LabView in this embodiment can digitally filter the collected digital signals, perform FFT spectrum analysis, extract and calculate the amplitude and effective value of the induced electromotive force, realize algorithm analysis and result display, storage and playback, and have good data analysis capabilities and human-computer interaction experience.

[0065] like Figure 7 As shown, the hammer detector, signal conditioning circuit, data acquisition module and power supply circuit of the central control module have the following characteristics:

[0066] The battery pack is composed of two 7.4V lithium batteries connected in series, which can provide 14.8V voltage during normal operation. It is equipped with a power adapter and can be charged and discharged repeatedly. The 14.8V voltage is stabilized at 12V through a protection circuit composed of a small current switch, a self-recovery fuse and an anti-reverse diode, and a voltage stabilization circuit based on the CJ7812 chip design. The 12V voltage is divided into two paths. One path is converted into -12V voltage through a voltage flip circuit based on the TPS5430 chip design, and the other path is converted into 5V power supply through a voltage stabilization circuit designed based on the CJ7805 chip design, and then 3.3V power supply is obtained through a voltage stabilization circuit based on the CJT1117B-3.3 design. The entire power module can provide ±12V, 5V, and 3.3V power supply, which meets the power supply requirements of the hammer detector, signal conditioning circuit, data acquisition module and central control module.

[0067] like Figure 6 As shown, this embodiment provides a method for searching and locating submarine cables based on the above device, which is characterized by comprising the following steps:

[0068] Step S1, controlling the underwater robot to move in the direction where the submarine cable may exist, until the induced electromotive force of the fourth detection rod appears, indicating that the submarine cable is approached; since the first, second and third detection rods are all below the fourth detection rod, all detection rods can detect the induced electromotive force at this time;

[0069] Step S2, obtaining the induced electromotive force amplitudes of the first, second and third detection rods, and calculating the horizontal spacing and vertical spacing between the submarine cable and the second detection rod;

[0070] Step S3, the underwater robot drives the hammer-shaped detector to rotate horizontally until the effective value of the induced electromotive force of the fourth detection rod is the maximum value of one rotation (the maximum value is obtained by the first rotation of 360°), then the fourth detection rod is perpendicular to the routing direction of the submarine cable, thereby determining the routing direction of the submarine cable;

[0071] Step S4, using the submarine cable route obtained in step S3, converting the spacing calculated in step S2 into two locations where the submarine cable may exist;

[0072] Step S5: According to the instantaneous positive and negative relationship between the induced electromotive force of the fourth detection rod and the third detection rod, the direction in which the magnetic lines of force generated by the submarine cable magnetic field pass through the fourth detection rod is obtained, thereby determining a unique submarine cable position point.

[0073] In this embodiment, step S2 includes the following steps:

[0074] Step S21, obtaining the induced electromotive force amplitudes of the first, second and third detection rods.

[0075] Set the horizontal angle between a single probe rod and the submarine cable to The x-axis component of the magnetic induction intensity at the center of the probe rod, that is, the effective magnetic induction intensity component of the probe rod is B x , the horizontal distance between the probe rod and the submarine cable is x', and the vertical distance is y', then the induced electromotive force of the probe rod is:

[0076]

[0077] Therefore, the induced electromotive force of the first detection rod, the second detection rod and the third detection rod is as follows:

[0078]

[0079] in, (Since the material and structure of each detection rod are the same, the coefficient K in each induced electromotive force is the same); y1, y2, y3 are the vertical distances between the submarine cable and the first, second, and third detection rods respectively, and x is the horizontal distance between the submarine cable and the center of the hammer-shaped detector.

[0080] Step S22: Calculate the vertical distance y between the submarine cable and the center of the hammer detector.

[0081] Assume that the center of the hammer-shaped detector falls on the center of the second detection rod, so y=y2; set the ratio of the induced electromotive force of the second detection rod to the third detection rod to be a, and the ratio of the induced electromotive force of the second detection rod to the first detection rod to be b, then the ratio equation group of the induced electromotive force is:

[0082]

[0083] According to the positional relationship between the submarine cable and each detection rod, we get:

[0084]

[0085] Wherein, L represents the distance between the center of the first detection rod and the center of the second detection rod, or the distance between the center of the second detection rod and the center of the third detection rod;

[0086] Combining the above equations, we get:

[0087]

[0088] Solve to get the vertical distance y between the submarine cable and the second detection rod:

[0089]

[0090] Substituting the ratio of the induced electromotive force of a and b, we get:

[0091]

[0092] Step S23: Calculate the horizontal distance x between the submarine cable and the hammer detector.

[0093] Add the two equations in the ratio equation group (1) of the induced electromotive force and substitute equation group (2) into it to obtain:

[0094]

[0095] Substitute the vertical spacing y calculated by formula (5) into formula (6) to calculate the horizontal spacing x:

[0096]

[0097] If the center of the hammer detector is directly above the submarine cable, x = 0 (the horizontal relative distance between the submarine cable and the hammer detector is zero), the induced electromotive force of the three position detection rods is zero, and the submarine cable position cannot be calculated by the induced electromotive force as before. At this time, the position of the submarine cable is determined by the inclined navigation method:

[0098] like Figure 3 As shown, the hammer-shaped detector is tilted 45° in the vertical direction of the submarine cable route (the route direction of the submarine cable is obtained by step S3), the tilt angle is maintained and the hammer-shaped detector is continued to be moved horizontally in this direction, and the induced electromotive force and the moving distance of the third and fourth detection rods are continuously monitored; when the induced electromotive force of the third or fourth detection rod drops to 0 during the movement, the movement of the hammer-shaped detector is stopped.

[0099] According to the characteristics of the magnetic lines of force of the submarine cable, at this time, one of the third or fourth detection rods is in the same direction as the magnetic lines of force, and the magnetic lines of force contribute the most to the generation of its induced electromotive force. The other is perpendicular to the direction of the magnetic lines of force, and the magnetic lines of force do not pass through the detection rod and no induced electromotive force is generated. At this time, the vertical distance between the hammer-shaped detector and the submarine cable is equal to the horizontal distance, that is, y=x, where x is equal to the horizontal distance moved by the hammer-shaped detector after tilting.

[0100] According to the route direction of the submarine cable, two possible locations of the submarine cable are determined; then, the relative position of the submarine cable is determined according to the instantaneous positive and negative relationship of the induced electromotive force on the third and fourth detection rods to determine the unique location coordinates of the submarine cable.

[0101] For the convenience of explanation, it is assumed that the induced electromotive force ε4 generated by the magnetic force lines generated by the submarine cable passing through the fourth detection rod from right to left is positive, and the induced electromotive force ε3 generated by the magnetic force lines generated by the submarine cable passing through the third detection rod from top to bottom is negative; from the positional relationship between the magnetic force lines of the submarine cable and the detector, it can be known that: by observing the positive and negative relationship between the induced electromotive force on the third and fourth detection rods at a certain moment, the direction of the submarine cable magnetic force lines passing through the coil can be inferred, and the relative position of the submarine cable can be determined by combining the properties of the direction of the submarine cable magnetic force lines and the horizontal relative distance x, and taking the instantaneous product of the induced electromotive force:

[0102] When ε3·ε4>0, the submarine cable is on the right side of the hammer detector;

[0103] When ε3·ε4<0, the submarine cable is on the left side of the hammer detector.

[0104] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A submarine cable search and positioning device, characterized in that: It comprises a hammer-shaped detector composed of a first detection rod, a second detection rod, a third detection rod and a fourth detection rod, a signal acquisition and control device and a data analysis platform, wherein the first detection rod, the second detection rod and the third detection rod are all position detection rods, have the same structure and are vertically equidistantly distributed in sequence, and the fourth detection rod is transversely arranged beside the third detection rod and forms an angle of 90° with the third detection rod; the hammer-shaped detector and the signal acquisition and control device are carried on an underwater robot for underwater measurement, and after initially detecting the signal of the submarine cable, the vertical and horizontal relative distances between the hammer-shaped detector and the submarine cable are first calculated according to the induced electromotive force of the position detection rod, and then the route deviation angle between the hammer-shaped detector and the submarine cable is calculated through the fourth detection rod and the third detection rod, thereby determining the unique position coordinates of the submarine cable; The method for searching and locating submarine cables based on the device comprises the following steps: Step S1, controlling the underwater robot to move in the direction where the submarine cable may exist, until the induced electromotive force of the fourth detection rod appears, indicating that the submarine cable is approached; since the first, second and third detection rods are all below the fourth detection rod, all detection rods can detect the induced electromotive force at this time; Step S2, obtaining the induced electromotive force amplitudes of the first, second and third detection rods, and calculating the horizontal and vertical spacings between the submarine cable and the hammer detector; Step S3, the underwater robot drives the hammer-shaped detector to rotate horizontally until the effective value of the induced electromotive force of the fourth detection rod reaches the maximum value of one rotation. At this time, the fourth detection rod is perpendicular to the routing direction of the submarine cable, thereby determining the routing direction of the submarine cable; Step S4, using the submarine cable route obtained in step S3, converting the spacing calculated in step S2 into two locations where the submarine cable may exist; Step S5, according to the instantaneous positive and negative relationship between the induced electromotive force of the fourth detection rod and the third detection rod, the direction in which the magnetic force lines generated by the magnetic field of the submarine cable pass through the fourth detection rod is obtained, thereby determining a unique submarine cable position point; The step S2 comprises the following steps: Step S21, obtaining the induced electromotive force amplitudes of the first, second and third detection rods; Set the horizontal angle between a single probe rod and the submarine cable to The x-axis component of the magnetic induction intensity at the center of the probe rod, that is, the effective magnetic induction intensity component of the probe rod is B x , the horizontal distance between the probe rod and the submarine cable is x', and the vertical distance is y', then the induced electromotive force of the probe rod is: Therefore, the induced electromotive force of the first detection rod, the second detection rod and the third detection rod is as follows: in, y1, y2, y3 are the vertical distances between the submarine cable and the first, second, and third detection rods, respectively, and x is the horizontal distance between the submarine cable and the center of the hammer-shaped detector; Step S22: Calculate the vertical distance y between the submarine cable and the center of the hammer detector; Assume that the center of the hammer-shaped detector falls on the center of the second detection rod, so y=y2; set the ratio of the induced electromotive force of the second detection rod to the third detection rod to be a, and the ratio of the induced electromotive force of the second detection rod to the first detection rod to be b, then the ratio equation group of the induced electromotive force is: According to the positional relationship between the submarine cable and each detection rod, we get: Wherein, L represents the distance between the center of the first detection rod and the center of the second detection rod, or the distance between the center of the second detection rod and the center of the third detection rod; Combining the above equations, we get: Solve to get the vertical distance y between the submarine cable and the second detection rod: Substituting the ratio of the induced electromotive force of a and b, we get: Step S23: Calculate the horizontal distance x between the submarine cable and the hammer detector; Add the two equations in the ratio equation group (1) of the induced electromotive force and substitute equation group (2) into it to obtain: Substitute the vertical spacing y calculated by formula (5) into formula (6) to calculate the horizontal spacing x: If the center of the hammer detector is directly above the submarine cable, x = 0, then the induced electromotive force of the three position detection rods is zero, and the induced electromotive force cannot be used to calculate the position of the submarine cable. At this time, the position of the submarine cable is determined by the inclined navigation method: Tilt the hammer detector 45° in the vertical direction of the submarine cable route, keep the tilt angle and continue to move the hammer detector horizontally in this direction, and constantly monitor the induced electromotive force and moving distance of the third and fourth detection rods; when the induced electromotive force of the third or fourth detection rod drops to 0 during the movement, stop moving the hammer detector; According to the characteristics of the magnetic force lines of the submarine cable, at this time, one of the third or fourth detection rods is in the same direction as the magnetic force lines, and the magnetic force lines contribute the most to the generation of its induced electromotive force, and the other is perpendicular to the direction of the magnetic force lines, and the magnetic force lines do not pass through the detection rod, and no induced electromotive force is generated. At this time, the vertical distance between the hammer detector and the submarine cable is equal to the horizontal distance, that is, y = x, where x is equal to the horizontal distance moved by the hammer detector after tilting; According to the route direction of the submarine cable, two possible locations of the submarine cable are determined; then, the relative position of the submarine cable is determined according to the instantaneous positive and negative relationship of the induced electromotive force on the third and fourth detection rods to determine the unique location coordinates of the submarine cable; In step S5, it is assumed that the induced electromotive force ε4 generated by the magnetic force lines generated by the submarine cable passing through the fourth detection rod from right to left is positive, and the induced electromotive force ε3 generated by the magnetic force lines generated by the submarine cable passing through the third detection rod from top to bottom is negative; from the positional relationship between the magnetic force lines of the submarine cable and the hammer-shaped detector, it can be known that: by observing the positive and negative relationship between the induced electromotive forces on the third and fourth detection rods at a certain moment, the direction in which the magnetic force lines of the submarine cable pass through the coil is inferred, and the relative position of the submarine cable is determined by combining the properties of the direction of the magnetic force lines of the submarine cable and the horizontal relative distance x, and performing the instantaneous product of the induced electromotive force: When ε3·ε4>0, the submarine cable is on the right side of the hammer detector; When ε3·ε4<0, the submarine cable is on the left side of the hammer detector.

2. The submarine cable searching and locating device according to claim 1, characterized in that: The first detection rod, the second detection rod, the third detection rod and the fourth detection rod are all magnetic induction coils, and the four magnetic induction coils form a detection array to perform magnetic signal detection.

3. The submarine cable searching and locating device according to claim 1, characterized in that: The signal acquisition and control device includes a signal conditioning circuit, a data acquisition module and a central control module. The hammer-shaped detector is connected to the central control module via the signal conditioning circuit, the data acquisition module and the central control module in sequence. The central control module communicates data with a host data analysis platform.

4. The submarine cable searching and locating device according to claim 3, characterized in that: The signal conditioning circuit includes an amplifier circuit based on ADA4004 and a filter circuit based on ADA4625, which are used for analog signal conditioning to achieve tiny signal amplification and 30Hz-70Hz bandpass filtering; the data acquisition module includes an AD7192 analog-to-digital converter, an SPI interface circuit and a power supply circuit, and the SPI interface circuit is used to communicate with the central control module; the central control module includes a control circuit with STM32H750XBH6 as a central processor, a key circuit, an Ethernet circuit, a CH340 interface circuit, an LED lamp and a buzzer group, and a SWD download and debugging circuit, and the SWD download and debugging circuit is used to communicate data with a data analysis platform.

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