阅读说明：本技术 一种多模式海缆埋深探测方法及探测系统 (Multi-mode submarine cable buried depth detection method and detection system ) 是由 张磊 乐彦杰 胡凯 徐蓓蓓 何旭涛 孙璐 陶诗洁 高震 杨国卿 梁尚清 于 2020-05-22 设计创作，主要内容包括：本发明涉及一种多模式海缆埋深探测方法及测量系统,该测量系统包括测量船、上位机、水密拖体和水密电缆,上位机设置于测量船上,水密拖体内部设有第一三轴磁通门和第二三轴磁通门、高度计、姿态仪和下位机；该方法包括：通过电流源向海缆输入交流电或直流电；采用水密电缆将水密拖体与测量船上的上位机进行连接；测量船通过水密电缆拖曳水密拖体对海域进行扫测；第一三轴磁通门和第二三轴磁通门分别采集磁场三分量,高度计采集第一三轴磁通门与海床的距离、姿态仪采集欧拉角,数据通过水密电缆传输给上位机；上位机根据向海缆输入的电流类型及采集到的数据计算海缆埋深。本发明测量形式多样,对海缆通交流电和直流电都可测量海缆埋深,操作简单。(The invention relates to a multi-mode submarine cable buried depth detection method and a multi-mode submarine cable buried depth detection system, wherein the multi-mode submarine cable buried depth detection system comprises a measurement ship, an upper computer, a watertight towed body and a watertight cable, wherein the upper computer is arranged on the measurement ship, and a first triaxial fluxgate, a second triaxial fluxgate, an altimeter, an attitude instrument and a lower computer are arranged in the watertight towed body; the method comprises the following steps: inputting alternating current or direct current to the submarine cable through a current source; connecting the watertight towed body with an upper computer on a measuring ship by using a watertight cable; the measuring ship drags the watertight towed body through the watertight cable to scan the sea area; the first triaxial fluxgate and the second triaxial fluxgate respectively collect three components of a magnetic field, the altimeter collects the distance between the first triaxial fluxgate and the seabed and the Euler angle collected by the attitude instrument, and data are transmitted to the upper computer through the watertight cable; and the upper computer calculates the submarine cable burial depth according to the current type input to the submarine cable and the acquired data. The invention has various measuring forms, can measure the submarine cable buried depth by electrifying the submarine cable with alternating current and direct current, and has simple operation.)

1. A multi-mode submarine cable buried depth detection method is characterized in that: which comprises the following steps:

1) inputting alternating current or direct current to the submarine cable through a current source;

2) connecting a watertight towed body internally provided with a first triaxial fluxgate, a second triaxial fluxgate, an altimeter, an attitude instrument and a lower computer with an upper computer on a measuring ship by adopting a watertight cable;

3) placing the watertight towed body in seawater, towing the watertight towed body by a measuring ship through a watertight cable and sweeping the sea area until the submarine cable is positioned under the measuring ship, and hovering the measuring ship above the submarine cable;

4) the first triaxial fluxgate collects the position E thereof₁Three components of the magnetic field, and the second three-axis fluxgate collects the position E thereof₂The altimeter acquires the distance h between the first triaxial fluxgate and the seabed₀The attitude instrument acquires X, Y, Z Euler angles in the axial direction, and the acquired data is transmitted to the upper computer through the lower computer and the watertight cable;

5) and the upper computer calculates the buried depth of the submarine cable according to the type of the current input to the submarine cable and the acquired data.

2. The method of claim 1, wherein: in the step 2), the second triaxial fluxgate is located right below the first triaxial fluxgate, the altimeter is as high as the first triaxial fluxgate, the second triaxial fluxgate, the altimeter and the attitude instrument are all in communication connection with the lower computer, and the lower computer is in communication connection with the upper computer through a watertight cable.

3. The method of claim 1, wherein: the current input through the current source in step 1) is alternating current, a current value I is recorded after the submarine cable outputs a sinusoidal current signal with a stable frequency omega, and the specific step of calculating the burial depth of the submarine cable in step 5) comprises the following steps:

5.1) forming an Euler rotation matrix R according to the collected Euler angles in the direction of the X, Y, Z axis_X(α)、R_Y(β)、R_Z(gamma), Euler rotation matrix R_X(α)、R_Y(β)、R_ZThe calculation of (γ) is:

wherein, alpha, beta and gamma are respectively an X-axis Euler angle, a Y-axis Euler angle and a Z-axis Euler angle;

5.2) correcting three components of the magnetic field at the first triaxial fluxgate and the second triaxial fluxgate through the Euler rotation matrix, wherein the correction counting mode is as follows:

wherein, B_x1、B_Y1、B_Z1Three components of magnetic field, B, collected for the first tri-axial fluxgate_x2、B_Y2、B_Z2Three components of magnetic field, B, collected for the second tri-axial fluxgate_x1’、B_Y1’、B_Z1’、B_x2’、B_Y2’、B_Z2' is the corrected three components of the magnetic field;

5.3) respectively carrying out Fourier transformation on the corrected three components of the magnetic field, and respectively taking the amplitude A of the X, Y, Z-axis magnetic field vector of the two three-axis fluxgates at the fixed frequency omega_x1、A_Y1、A_Z1、A_x2、A_Y2、A_Z2；

5.4) calculating the distance between the first triaxial fluxgate and the submarine cable, wherein the distance is calculated in the following mode:

R₁＝R₂+d₀(7)；

wherein mu₀For vacuum permeability, R₁Is the distance, R, between the first triaxial fluxgate and the submarine cable₂Is the distance between the second triaxial fluxgate and the submarine cable, d₀The distance between the first triaxial fluxgate and the second triaxial fluxgate is defined;

5.5) calculating the buried depth h of the submarine cable, wherein the calculation formula is as follows:

h＝R₁-h₀(8)；

wherein h is₀The distance between the first triaxial fluxgate and the seabed is the output of the altimeter.

4. The method of claim 1, wherein: the step 1) is to input direct current through a current source, and the step 5) is to calculate the burial depth of the submarine cable, and the step comprises the following specific steps:

5.1) forming an Euler rotation matrix R according to the collected Euler angles in the direction of the X, Y, Z axis_X(α)、R_Y(β)、R_Z(gamma), Euler rotation matrix R_X(α)、R_Y(β)、R_ZThe calculation of (γ) is:

wherein, alpha, beta and gamma are respectively an X-axis Euler angle, a Y-axis Euler angle and a Z-axis Euler angle;

5.2) correcting three components of the magnetic field at the first triaxial fluxgate and the second triaxial fluxgate through the Euler rotation matrix, wherein the correction counting mode is as follows:

wherein, B_x1、B_Y1、B_Z1Three components of magnetic field, B, collected for the first tri-axial fluxgate_x2、B_Y2、B_Z2Three components of magnetic field, B, collected for the second tri-axial fluxgate_x1’、B_Y1’、B_Z1’、B_x2’、B_Y2’、B_Z2' is the corrected three components of the magnetic field;

5.3) calculating the total magnetic field B according to the corrected three components of the magnetic field₁、B₂The calculation formula is as follows:

5.4) according to the total magnetic field B₁、B₂Calculating the distance between the first triaxial fluxgate and the submarine cable, wherein the calculation formula is as follows:

R₁＝R₂+d₀(13)；

wherein k is a proportionality coefficient, R₁Is the distance, R, between the first triaxial fluxgate and the submarine cable₂Is the distance between the second triaxial fluxgate and the submarine cable, d₀The distance between the first triaxial fluxgate and the second triaxial fluxgate is defined;

5.5) calculating the buried depth h of the submarine cable, wherein the calculation formula is as follows:

h＝R₁-h₀(8)；

h₀the distance between the first triaxial fluxgate and the seabed is the output of the altimeter.

5. The method of claim 1, wherein: and 3) dragging the watertight towed body by the measuring ship through the watertight cable and rapidly scanning the sea area by adopting an S-shaped route, continuously measuring the X-axis magnetic field of the triaxial fluxgate in the scanning process and transmitting the X-axis magnetic field to the upper computer through the watertight cable, generating an X-axis magnetic field waveform by the upper computer according to the X-axis magnetic field of the continuous side, and indicating that the submarine cable is positioned under the measuring ship when the X-axis magnetic field waveform has a peak value.

6. The method of claim 1, wherein: when alternating current is input into the submarine cable, the method further comprises a step 6), and the step 6) is as follows: adjusting the frequency omega of the current, and repeating the steps 1) to 5) to obtain the submarine cable buried depth under continuous frequency.

7. A multi-mode submarine cable burial depth detection system is characterized in that: the device comprises a measuring ship, an upper computer, a watertight towed body and a watertight cable; the upper computer is arranged on the measuring ship; the watertight towed body is connected with the measuring ship through a watertight cable, a first triaxial fluxgate and a second triaxial fluxgate for collecting three components of a magnetic field and a distance h between the first triaxial fluxgate and the seabed are arranged in the watertight towed body₀The height gauge, the attitude instrument used for collecting the Euler angle in the X, Y, Z axis direction and the lower computer used for receiving and transmitting data are all in communication connection with the lower computer, and the lower computer is in communication connection with the upper computer through a watertight cable.

8. The multi-mode submarine cable burial depth detection system according to claim 7, wherein: the second triaxial fluxgate is positioned right below the first triaxial fluxgate, and the altimeter is as high as the first triaxial fluxgate.

9. The multi-mode submarine cable burial depth detection system according to claim 7, wherein: the watertight towed body comprises a nonmetal watertight bin, and the first triaxial fluxgate, the second triaxial fluxgate, the altimeter, the attitude instrument and the lower computer are all fixed in the nonmetal watertight bin.

10. The multi-mode submarine cable burial depth detection system according to claim 7, wherein: the device also comprises a current source for inputting current to the submarine cable, wherein the current source is an alternating current source or a direct current source.

Technical Field

The invention relates to the field of submarine cable operation and maintenance, in particular to a multi-mode submarine cable buried depth detection method and a multi-mode submarine cable buried depth detection system, which are used for improving submarine cable buried depth measurement efficiency.

Background

Submarine cable burial depth detection is an indispensable link for submarine cable operation and maintenance. When the submarine cable breaks down, the accuracy and the measuring efficiency of submarine cable buried depth data will influence the time cost and the economic cost of maintenance. Currently, the submarine cable burial depth is determined by receiving the magnetic field change generated in the space by the submarine cable through a receiving coil instrument. The common methods are that a probe measures the buried depth of a submarine cable and a multi-coil measures the buried depth.

The probe-based submarine cable detection system comprises a probe sensing module, an interference signal filtering module, a peak signal extraction module, a core processor module, a keyboard module, a liquid crystal display module and a power supply module, wherein the probe sensing module is used for detecting the submarine cable burial depth, and the double-probe-based submarine cable detection system is disclosed as CN 105044784A; the probe sensing module adopts a double-probe structure, the two probes are connected through a connecting rod with a fixed length, the axial directions of the two probes are parallel to each other and are perpendicular to the connecting rod, and the detection method comprises the steps of detecting the position, the trend and the burial depth of the submarine cable.

The multi-coil buried depth detection device comprises three groups of induction coils for detecting induced electromotive force of a submarine cable, wherein the three groups of induction coils are mutually orthogonal, each group of induction coil is an annular coil, the detection device also comprises a data transmission module and an upper computer, and the three groups of induction coils, the data transmission module and the upper computer are sequentially in communication connection; the three groups of induction coils transmit the acquired corresponding induced electromotive force to the data transmission module, and the data transmission module processes the information of the maximum induced electromotive force and transmits the information to the upper computer.

The two modes are adopted to measure the buried depth of the submarine cable, and the method is only suitable for the situation that the submarine cable is electrified with alternating current, is not suitable for the situation that the submarine cable is electrified with direct current, and has a single application range for measuring the buried depth of the submarine cable; when multiple coils are used for measuring the buried depth, the structure of the coils can influence the selection of the optimal working frequency of the coils, and the determination of the structure of the coils means the determination of the optimal working frequency of the coils; one of 25Hz, 50Hz and 133Hz is generally selected for measurement, and the measurement frequency is not continuous.

Disclosure of Invention

The invention aims to provide a multi-mode submarine cable buried depth detection method and system aiming at the defects of single application range, discontinuous measurement frequency and the like of submarine cable buried depth measurement in the prior art.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

the invention relates to a multi-mode submarine cable buried depth detection method, which comprises the following steps:

1) inputting alternating current or direct current to the submarine cable through a current source;

2) connecting a watertight towed body internally provided with a first triaxial fluxgate, a second triaxial fluxgate, an altimeter, an attitude instrument and a lower computer with an upper computer on a measuring ship by adopting a watertight cable;

3) placing the watertight towed body in seawater, towing the watertight towed body by a measuring ship through a watertight cable and sweeping the sea area until the submarine cable is positioned under the measuring ship, and hovering the measuring ship above the submarine cable;

4) the first triaxial fluxgate collects the position E thereof₁Three components of the magnetic field, and the second three-axis fluxgate collects the position E thereof₂The altimeter acquires the distance h between the first triaxial fluxgate and the seabed₀The attitude instrument acquires X, Y, Z Euler angles in the axial direction, and the acquired data is transmitted to the upper computer through the lower computer and the watertight cable;

5) and the upper computer calculates the buried depth of the submarine cable according to the type of the current input to the submarine cable and the acquired data.

The current source in step 1) of the present invention is to input ac or dc power to the submarine cable, and may be a current source carried by the submarine cable or a current source provided separately, and specifically may be an alternating current source or a dc current source.

Preferably, in the step 2), the second triaxial fluxgate is located right below the first triaxial fluxgate, the altimeter is as high as the first triaxial fluxgate, the second triaxial fluxgate, the altimeter and the attitude instrument are all in communication connection with the lower computer, and the lower computer is in communication connection with the upper computer through a watertight cable.

Preferably, the current source inputs alternating current in step 1), and the current value I is recorded after the submarine cable outputs a sinusoidal current signal with a stable frequency ω, and the specific step of calculating the burial depth of the submarine cable in step 5) includes:

5.1) forming an Euler rotation matrix R according to the collected Euler angles in the direction of the X, Y, Z axis_X(α)、R_Y(β)、R_Z(gamma), Euler rotation matrix R_X(α)、R_Y(β)、R_ZThe calculation of (γ) is:

wherein, alpha, beta and gamma are respectively an X-axis Euler angle, a Y-axis Euler angle and a Z-axis Euler angle;

5.2) correcting three components of the magnetic field at the first triaxial fluxgate and the second triaxial fluxgate through the Euler rotation matrix, wherein the correction counting mode is as follows:

wherein, B_x1、B_Y1、B_Z1Three components of magnetic field, B, collected for the first tri-axial fluxgate_x2、B_Y2、B_Z2Three components of magnetic field, B, collected for the second tri-axial fluxgate_x1’、B_Y1’、B_Z1’、B_x2’、B_Y2’、B_Z2' is the corrected three components of the magnetic field;

5.3) respectively carrying out Fourier transformation on the corrected three components of the magnetic field, and respectively taking the amplitude A of the X, Y, Z-axis magnetic field vector of the two three-axis fluxgates at the fixed frequency omega_x1、A_Y1、A_Z1、A_x2、A_Y2、A_Z2；

5.4) calculating the distance between the first triaxial fluxgate and the submarine cable, wherein the distance is calculated in the following mode:

R₁＝R₂+d₀(7)；

wherein mu₀For vacuum permeability, R₁Is the distance, R, between the first triaxial fluxgate and the submarine cable₂Is the distance between the second triaxial fluxgate and the submarine cable, d₀The distance between the first triaxial fluxgate and the second triaxial fluxgate is defined;

5.5) calculating the buried depth h of the submarine cable, wherein the calculation formula is as follows:

h＝R₁-h₀(8)；

wherein h is₀The distance between the first triaxial fluxgate and the seabed is the output of the altimeter.

Preferably, the input of the direct current through the current source in step 1) is direct current, and the specific step of calculating the burial depth of the submarine cable in step 5) includes:

5.1) forming an Euler rotation matrix R according to the collected Euler angles in the direction of the X, Y, Z axis_X(α)、R_Y(β)、R_Z(gamma), Euler rotation matrix R_X(α)、R_Y(β)、R_ZThe calculation of (γ) is:

wherein, alpha, beta and gamma are respectively an X-axis Euler angle, a Y-axis Euler angle and a Z-axis Euler angle;

5.2) correcting three components of the magnetic field at the first triaxial fluxgate and the second triaxial fluxgate through the Euler rotation matrix, wherein the correction counting mode is as follows:

wherein, B_x1、B_Y1、B_Z1Three components of magnetic field, B, collected for the first tri-axial fluxgate_x2、B_Y2、B_Z2Three components of magnetic field, B, collected for the second tri-axial fluxgate_x1’、B_Y1’、B_Z1’、B_x2’、B_Y2’、B_Z2' is the corrected three components of the magnetic field;

5.3) calculating the total magnetic field B according to the corrected three components of the magnetic field₁、B₂The calculation formula is as follows:

5.4) according to the total magnetic field B₁、B₂Calculating the distance between the first triaxial fluxgate and the submarine cable, wherein the calculation formula is as follows:

R₁＝R₂+d₀(13)；

wherein k is a proportionality coefficient, R₁Is the distance, R, between the first triaxial fluxgate and the submarine cable₂Is the distance between the second triaxial fluxgate and the submarine cable, d₀The distance between the first triaxial fluxgate and the second triaxial fluxgate is defined;

5.5) calculating the buried depth h of the submarine cable, wherein the calculation formula is as follows:

h＝R₁-h₀(8)；

h₀the distance between the first triaxial fluxgate and the seabed is the output of the altimeter.

Preferably, in the step 3), the measuring ship drags the watertight towed body through the watertight cable and rapidly scans the sea area by adopting an S-shaped route, the triaxial fluxgate continuously measures the X-axis magnetic field at the side in the scanning process and transmits the X-axis magnetic field to the upper computer through the watertight cable, the upper computer generates an X-axis magnetic field waveform according to the X-axis magnetic field at the continuous side, and when the X-axis magnetic field waveform has a peak value, the sea cable is positioned under the measuring ship.

Preferably, when the input of the alternating current to the submarine cable is alternating current, the method further comprises the step 6), and the step 6) comprises the following steps: adjusting the frequency omega of the current, and repeating the steps 1) to 5) to obtain the submarine cable buried depth under continuous frequency.

The invention also relates to a multi-mode submarine cable buried depth detection system, which comprises a measuring ship, an upper computer, a watertight towed body and a watertight cable; the upper computer is arranged on the measuring ship; the watertight towed body is connected with the measuring ship through a watertight cable, a first triaxial fluxgate and a second triaxial fluxgate for collecting three components of a magnetic field and a distance h between the first triaxial fluxgate and the seabed are arranged in the watertight towed body₀The height gauge, the attitude instrument used for collecting the Euler angle in the X, Y, Z axis direction and the lower computer used for receiving and transmitting data are all in communication connection with the lower computer, and the lower computer is in communication connection with the upper computer through a watertight cable.

Preferably, the second triaxial fluxgate is located right below the first triaxial fluxgate, and the altimeter is as high as the first triaxial fluxgate.

Preferably, the watertight towed body comprises a nonmetal watertight bin, and the first triaxial fluxgate, the second triaxial fluxgate, the altimeter, the attitude instrument and the lower computer are all fixed in the nonmetal watertight bin.

Preferably, the device further comprises a current source for inputting current to the submarine cable, wherein the current source is an alternating current source or a direct current source.

Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:

1. the method selects a corresponding algorithm according to the type of the current input to the submarine cable, calculates the buried depth of the submarine cable according to the acquired data, can measure the buried depth of the submarine cable for both alternating current and direct current of the submarine cable, and has wider application range.

2. When alternating current is input into the submarine cable, the submarine cable burial depth can be repeatedly measured by adjusting the frequency omega of the current, and the submarine cable burial depth under continuous frequency can be obtained.

3. The invention only needs to operate the high-power alternating current source, the watertight towed body and the upper computer, and has simple operation.

Drawings

FIG. 1 is a block diagram of a multi-mode submarine cable buried depth detection system according to an embodiment;

fig. 2 is a block diagram of a multi-mode submarine cable buried depth detection system according to the second embodiment and the third embodiment;

FIG. 3 is a block diagram of a surface tow;

fig. 4 is a schematic diagram of the relative positions of the measuring ship, the submarine cable and the two fluxgates.

Description of the labeling: the method comprises the following steps of 1-current source, 2-watertight towed body, 3-first triaxial fluxgate, 4-second triaxial fluxgate, 5-altimeter, 6-attitude instrument, 7-lower computer, 8-watertight cable, 9-upper computer, 10-measuring ship and 11-submarine cable.

Detailed Description

In order to further understand the present invention, the following examples are described in detail, and the following examples are carried out on the premise of the technical solution of the present invention to give detailed embodiments, but the scope of the present invention is not limited to the following examples.