A method and system for measuring and controlling the length of a ploughed-in plough-in cable

Abstract

The application relates to the technical field of submarine cable laying, and particularly discloses a buried plow into plow mouth submarine cable length measurement and control method and system. The submarine cable length measurement method and system adopts a dual-frequency sonar to perform sonar detection on the buried plow into the plow mouth to obtain a sonar image, adopts a turbid water camera to shoot the buried plow into the plow mouth to obtain a camera image, combines the specific size of the submarine cable, performs three-dimensional reconstruction on the sonar image and the camera image, displays a submarine cable three-dimensional graph, and can infer and identify the working state and the length of the submarine cable according to the graph. The submarine cable length control method and system can adjust the cable laying speed of a submarine cable ship in real time according to the real-time predicted submarine cable length of the buried plow into the plow mouth, can keep the length of the submarine cable into the plow mouth constant in the laying of the complex seabed environment, that is, can keep the tension of the submarine cable into the plow mouth constant in the laying of the complex seabed environment and further protect the submarine cable.

Description

Technical Field

[0001] This invention relates to the field of submarine cable laying technology, and in particular to a method for measuring the length of a submarine cable buried in the plowshare, a system for measuring the length of a submarine cable buried in the plowshare, a method for controlling the length of a submarine cable buried in the plowshare, and a system for controlling the length of a submarine cable buried in the plowshare. Background Technology

[0002] Submarine cables are cables wrapped in insulating materials and laid on the seabed. They are divided into submarine communication cables and submarine power cables. Modern submarine communication cables use optical fibers as materials to transmit telephone and Internet signals for telecommunications transmission.

[0003] In submarine cable construction, cables need to be buried on the seabed. The catenary method is currently a mainstream laying method, using a cable-laying vessel in conjunction with a burial plow. During catenary laying, the burial plow is towed by the cable-laying vessel, requiring careful control of cable tension. Excessive tension can cause mechanical damage, while insufficient tension can lead to cable twisting. The laying speed directly determines the cable tension, which can be characterized by the length of cable within a defined local space at the point where the burial plow enters the plow's inlet. A longer cable within this space indicates lower tension, and vice versa.

[0004] The seabed environment is quite complex. When the sled is laid uphill or downhill, if the original cable laying speed is maintained, the tension of the submarine cable will increase or decrease. If it is not adjusted in time, it will have adverse effects. However, there is currently a lack of a reliable method, system or device for real-time prediction of submarine cable length, as well as a method, system or device for controlling the cable laying speed based on the real-time predicted submarine cable length. Summary of the Invention

[0005] This invention provides a method and system for measuring and controlling the length of submarine cable buried in the plowshare. The technical problem it solves is: how to predict the length of submarine cable in the local space of the plowshare in real time, and how to control the cable laying speed according to the predicted cable length to keep the cable length constant.

[0006] To solve the above technical problems, this invention provides a method for measuring the length of submarine cable buried in the plowshare, comprising the following steps:

[0007] S1. Use dual-frequency sonar to detect the sonar image at the plow entry point of the buried plow and use a turbid water camera to take a camera image at the plow entry point of the buried plow.

[0008] S2. Based on the sonar image, the camera image, and the size parameters of the submarine cable, perform three-dimensional reconstruction of the submarine cable at the burial point of the plow to obtain the attitude image of the submarine cable.

[0009] S3. Input the submarine cable attitude image into the submarine cable working state recognition model based on neural network to obtain the working state of the submarine cable at the burial plow entry point.

[0010] S4. Determine if the working status of the submarine cable at the plow entry point is abnormal. If it is abnormal, an alarm will be triggered directly. If it is normal, proceed to step S5.

[0011] S5. Identify the length of the submarine cable at the point where it enters the plough based on the submarine cable attitude image.

[0012] Furthermore, step S2 specifically includes the following steps:

[0013] S21. After preprocessing the sonar image, extract the outline of the submarine cable in the sonar image; after preprocessing the camera image, crop the submarine cable area in the camera image.

[0014] S22. Perform three-dimensional reconstruction of the submarine cable outline and submarine cable region at the current acquisition time and the N+1 pairs of the N previous acquisition times, combined with the size parameters of the submarine cable, to obtain N+1 reconstructed images of the submarine cable.

[0015] S23. Based on the observation of the cable attitude change pattern in the N+1 reconstructed images, predict the cable attitude at the next sampling time.

[0016] S24. Based on the predicted cable attitude at the next sampling time, the reconstructed cable image at the next sampling time is corrected to obtain the cable attitude image.

[0017] Furthermore, in step S4, when the working state is abnormal and an alarm is triggered, the submarine cable fault status information is also transmitted to the cable laying control terminal.

[0018] Furthermore, both the dual-frequency sonar and the turbid water camera are fixedly installed on the burial plow, and the detection range of the dual-frequency sonar and the shooting range of the turbid water camera remain fixed relative to the burial plow.

[0019] During the 3D reconstruction, the local space where the plough is buried is first determined based on the detection range of the dual-frequency sonar and the shooting range of the turbid water camera. Then, the submarine cable within the local space where the plough is buried is reconstructed in 3D.

[0020] The dual-frequency sonar is located at the upper left of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening; the turbid water camera is located at the upper right of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening.

[0021] The present invention also provides a system for measuring the length of submarine cables buried in the plowshare, the key features of which are: a dual-frequency sonar, a turbid water camera and a length prediction module; the length prediction module includes a three-dimensional reconstruction unit, a submarine cable status identification unit, a submarine cable status determination unit, an alarm unit and a length prediction unit;

[0022] The dual-frequency sonar is used to perform sonar detection at the location where the plow enters the plow mouth to obtain sonar images, which are then input into the three-dimensional reconstruction unit.

[0023] The turbid water camera is used to capture camera images at the point where the plow enters the plow mouth and input them into the three-dimensional reconstruction unit.

[0024] The three-dimensional reconstruction unit is used to perform three-dimensional reconstruction of the submarine cable at the plowing mouth based on the sonar image, the camera image and the size parameters of the submarine cable, to obtain the submarine cable attitude image and input it into the submarine cable state recognition unit.

[0025] The submarine cable status recognition unit is used to input the submarine cable attitude image into the submarine cable working status recognition model based on neural network to obtain the working status of the submarine cable at the burial plow entry point.

[0026] The submarine cable status determination unit is used to determine whether the working status of the submarine cable at the burial plow entry point is abnormal. If it is abnormal, it sends an abnormal signal to the alarm unit. If it is normal, it inputs the submarine cable attitude image into the length prediction unit.

[0027] The alarm unit is used to trigger an alarm when an abnormal signal is received;

[0028] The length prediction unit is used to identify the length of the submarine cable at the point where it is buried by the plough based on the submarine cable attitude image.

[0029] Preferably, the three-dimensional reconstruction unit includes an image preprocessing subunit, a three-dimensional reconstruction subunit, a change law acquisition subunit, and a pose image correction subunit;

[0030] The image preprocessing subunit is used to preprocess the sonar image and the camera image;

[0031] The three-dimensional reconstruction subunit is used to perform three-dimensional reconstruction of the submarine cable outline and submarine cable region at the current acquisition time and N+1 times before the current acquisition time, combined with the size parameters of the submarine cable, to obtain N+1 submarine cable reconstruction images.

[0032] The change pattern acquisition subunit is used to acquire the attitude change pattern of the submarine cable based on the reconstructed images of N+1 submarine cables.

[0033] The attitude image correction subunit is used to correct the reconstructed image of the submarine cable at the next sampling time according to the attitude change law of the submarine cable, so as to obtain the attitude image of the submarine cable.

[0034] Preferably, the submarine cable status determination unit is also used to transmit submarine cable fault status information to the cable laying control terminal when sending an abnormal signal to the alarm unit;

[0035] Both the dual-frequency sonar and the turbid water camera are fixedly installed on the burial plow, and the detection range of the dual-frequency sonar and the shooting range of the turbid water camera remain fixed relative to the burial plow.

[0036] Based on the detection range of the dual-frequency sonar and the shooting range of the turbid water camera, a three-dimensional local space for burying the plowshare into the plowshare is determined. During the three-dimensional reconstruction, only the submarine cable within the local space for burying the plowshare into the plowshare is reconstructed in three dimensions.

[0037] The dual-frequency sonar is located at the upper left of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening; the turbid water camera is located at the upper right of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening.

[0038] This invention also provides a method for controlling the length of submarine cable buried in the plowshare, the key of which is that it includes the following steps:

[0039] A1. The length of the submarine cable buried in the plowshare opening is obtained by the aforementioned method for measuring the length of the submarine cable buried in the plowshare opening or the aforementioned system for measuring the length of the submarine cable buried in the plowshare opening, and is denoted as γ2.

[0040] A2. Subtract the measured cable length γ2 from the preset cable length γ1 to obtain the difference Δγ = γ2 - γ1;

[0041] A3. Combining Δγ with the speed of the cable-laying vessel and the speed of the burying plow, adjust the cable-laying speed and return to step A1 to remeasure the adjusted cable length, forming a closed-loop control until γ2 = γ1.

[0042] Furthermore, if step A1 fails to measure the length γ2 of the submarine cable within the local space where the plough cuts into the plough opening, but instead obtains information about the cable fault status, then the length control method further includes the following steps:

[0043] The cable laying speed is controlled at 0, the burying plow speed is controlled at 0, and the speed of the cable ship is controlled at 0.

[0044] The present invention also provides a control system for the length of submarine cable buried in the plowshare, the key features of which are: a length measurement module, a length comparison module, and a speed control module;

[0045] The length measurement module is used to obtain the length of the submarine cable within the local space of the buried plowshare using the buried plowshare entry plowshare submarine cable length measurement method or the buried plowshare entry plowshare submarine cable length measurement system, denoted as γ2.

[0046] The length comparison module is used to calculate the difference between the measured submarine cable length γ2 and the preset value of submarine cable length γ1, and obtain the difference Δγ = γ2 - γ1.

[0047] The speed control module is used to combine Δγ with the speed of the cable ship and the speed of the burying plow, adjust the cable laying speed and then return to step A1 to remeasure the adjusted cable length, forming a closed-loop control until γ2 = γ1.

[0048] If the length measurement module fails to measure the length γ2 of the submarine cable within the local space of the burial plow and instead obtains information about the submarine cable fault status, the speed control module is also used to control the cable laying speed to 0, the burial plow speed to 0, and the submarine cable ship speed to 0.

[0049] The present invention provides a method and system for measuring the length of submarine cable at the burial plow entry point. This method uses dual-frequency sonar to detect the entry point of the plow and obtain sonar images. It also uses a turbid water camera to capture images of the same location. Combining the specific dimensions of the submarine cable, the sonar and camera images are used to perform a three-dimensional reconstruction. Based on the reconstructed images, the cable's operational status is identified. When the cable is in normal working condition, image processing technology is used to predict the cable length in the reconstructed attitude image. However, when the cable is in a faulty state, the predicted length will be inaccurate and meaningless. In this case, cable laying must be paused to clear the fault. Cable laying can only resume after the fault is cleared. During subsequent cable laying processes, images are re-acquired for three-dimensional reconstruction and status detection. This invention is based on dual-frequency sonar and turbid water camera for three-dimensional reconstruction. Dual-frequency sonar has better contour detection results in turbid water and can obtain more detailed parameters. Image enhancement technology is used to fuse the information of the two, and the laying posture of the submarine cable on the seabed is determined by three-dimensional reconstruction based on the specific size parameters of the submarine cable and the fused image. Then, prediction is made based on the laying posture, and the prediction results are fast and accurate.

[0050] The method and system for controlling the length of submarine cable at the burial plow entry point provided by this invention adjusts the cable-laying speed of the cable-laying vessel in real time based on the real-time predicted length of the submarine cable at the burial plow entry point. This ensures that the length of the submarine cable at the burial plow entry point remains constant during laying in complex seabed environments, which in turn ensures that the tension of the submarine cable at the burial plow entry point remains constant during laying in complex seabed environments. This guarantees that the submarine cable enters the burial plow with a relatively ideal tension state, thereby protecting the submarine cable from mechanical damage due to excessive tension or twisting due to insufficient tension. Attached Figure Description

[0051] Figure 1 This is a flowchart of the method for measuring the length of submarine cable buried in the plow mouth provided in Embodiment 1 of the present invention;

[0052] Figure 2 This is an installation diagram of the dual-frequency sonar and turbid water camera provided in Embodiment 1 of the present invention;

[0053] Figure 3 This is a flowchart of three-dimensional reconstruction provided in Embodiment 1 of the present invention;

[0054] Figure 4 This is a structural diagram of a submarine cable length measurement system for burying a plowshare in the plow mouth, provided in Embodiment 2 of the present invention;

[0055] Figure 5 This is a flowchart of a method for controlling the length of a submarine cable buried in the plowshare, provided in Embodiment 3 of the present invention;

[0056] Figure 6 This is a structural diagram of a submarine cable length control system for burying the plowshare in the plow mouth, provided in Embodiment 4 of the present invention.

[0057] Figure reference numerals: 1-Dual-frequency sonar, 2-Turbid water camera, 3-Length prediction module, 31-3D reconstruction unit, 32-Submarine cable status identification unit, 33-Submarine cable status determination unit, 34-Alarm unit, 35-Length prediction unit, 311-Image preprocessing subunit, 312-3D reconstruction subunit, 313-Change pattern acquisition subunit, 314-Attitude image correction subunit, 4-Length measurement module, 5-Length comparison module, 6-Speed ​​control module. Detailed Implementation

[0058] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The embodiments are given for illustrative purposes only and should not be construed as limiting the present invention. The accompanying drawings are for reference and illustration only and do not constitute a limitation on the scope of patent protection of the present invention, because many changes can be made to the present invention without departing from the spirit and scope of the present invention.

[0059] Example 1

[0060] This invention provides a method for measuring the length of a submarine cable embedded in the plowshare, such as... Figure 1 As shown in the flowchart, the method includes the following steps:

[0061] S1. Use dual-frequency sonar 1 to perform sonar detection at the burial plow entry point to obtain sonar images, and use turbid water camera 2 to take camera images at the burial plow entry point.

[0062] S2. Based on sonar images, camera images, and the size parameters of the submarine cable, a three-dimensional reconstruction of the submarine cable at the point where it is buried in the plowshare is performed to obtain the attitude image of the submarine cable.

[0063] S3. Input the submarine cable attitude image into the submarine cable working status recognition model based on neural network to obtain the working status of the submarine cable at the burial plow entry point.

[0064] S4. Determine if the working status of the submarine cable at the plow entry point is abnormal. If it is abnormal, an alarm will be triggered directly. If it is normal, proceed to step S5.

[0065] S5. Identify the length of the submarine cable at the point where it enters the plough cut based on the submarine cable attitude image.

[0066] In step S4, when the working status is abnormal and an alarm is triggered, the cable fault status information (knotting, foreign object snagging, etc.) will also be transmitted to the cable laying control terminal. The cable laying control terminal will suspend cable laying to clear the fault, and cable laying will resume after the fault is cleared.

[0067] like Figure 2 As shown, to ensure that the detection area of ​​dual-frequency sonar 1 and the imaging area of ​​turbid water camera 2 both cover the pre-defined local space within the burial plow's opening, and to allow operation at different angles of the submarine cable (to make the reconstructed 3D image more realistic) without affecting the normal laying of the submarine cable, both dual-frequency sonar 1 and turbid water camera 2 are fixedly installed on the burial plow. The detection range of dual-frequency sonar 1 and the imaging range of turbid water camera 2 remain constant relative to the burial plow. During 3D reconstruction, the local space within the burial plow's opening is first determined based on the detection range of dual-frequency sonar 1 and the imaging range of turbid water camera 2. Then, 3D reconstruction is performed only on the submarine cable within this local space.

[0068] Dual-frequency sonar 1 is located at the upper left of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening; turbid water camera 2 is located at the upper right of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening.

[0069] To make the reconstructed submarine cable images more accurate and realistic, such as... Figure 3 As shown, step S2 specifically includes the following steps:

[0070] S21. After preprocessing the sonar image, extract the outline of the submarine cable in the sonar image; after preprocessing the camera image, crop the submarine cable area in the camera image.

[0071] S22. Perform three-dimensional reconstruction of the submarine cable outline and submarine cable region at the current acquisition time and the N+1 pairs of the N previous acquisition times, combined with the size parameters of the submarine cable, to obtain N+1 reconstructed images of the submarine cable.

[0072] S23. Identify the cable attitude change pattern based on N+1 reconstructed images of the submarine cable and predict the cable attitude at the next sampling time.

[0073] S24. Based on the predicted cable attitude at the next sampling time, the reconstructed cable image at the next sampling time is corrected to obtain the cable attitude image.

[0074] Specifically, step S23 involves inputting N+1 reconstructed images of the submarine cable into a trained neural network model, summarizing the trend of submarine cable attitude change, and outputting the predicted submarine cable attitude at the next sampling time (or within a future period).

[0075] The method for measuring the length of submarine cable at the plowshare entry point provided in this invention involves using a dual-frequency sonar 1 to detect the entry point of the plowshare and obtain a sonar image, and using a turbid water camera 2 to capture a camera image at the same location. A three-dimensional reconstruction is then performed based on the sonar and camera images. The working status of the submarine cable is then identified based on the reconstructed image. When the cable is in normal working condition, the length of the cable in the reconstructed image is predicted using image processing technology. However, when the cable is in fault condition, the predicted length will be inaccurate and meaningless. In this case, cable laying must be paused to clear the fault. Cable laying can only resume after the fault is cleared. During subsequent cable laying processes, images are re-acquired for three-dimensional reconstruction and status detection. This invention uses a dual-frequency sonar 1 and a turbid water camera 2 for three-dimensional reconstruction. The dual-frequency sonar 1 has better contour detection results in turbid water and can obtain more detailed parameters. The two are fused using image enhancement technology, and the fused image is combined with the specific size parameters of the submarine cable to perform three-dimensional reconstruction to determine the laying shape of the submarine cable on the seabed. Then, prediction is made based on the laying shape, and the prediction results are fast and accurate.

[0076] Example 2

[0077] like Figure 4 As shown, corresponding to the method of Embodiment 1, this embodiment provides a system for measuring the length of a submarine cable buried in the plowshare, which includes a dual-frequency sonar 1, a turbid water camera 2, and a length prediction module 3; the length prediction module 3 includes a three-dimensional reconstruction unit 31, a submarine cable status identification unit 32, a submarine cable status determination unit 33, an alarm unit 34, and a length prediction unit 35.

[0078] The dual-frequency sonar 1 is used to perform sonar detection at the location where the plow enters the plow mouth to obtain sonar images and input them into the three-dimensional reconstruction unit 31;

[0079] The turbid water camera 2 is used to capture images of the plow entry point where the plow is buried, and input the images into the 3D reconstruction unit 31.

[0080] The 3D reconstruction unit 31 is used to perform 3D reconstruction of the submarine cable at the burial plow mouth based on sonar images, camera images and submarine cable size parameters, to obtain submarine cable attitude images and input them into the submarine cable status recognition unit 32.

[0081] The submarine cable status recognition unit 32 is used to input the submarine cable attitude image into the submarine cable working status recognition model based on neural network to obtain the working status of the submarine cable at the burial plow entry point.

[0082] The submarine cable status determination unit 33 is used to determine whether the working status of the submarine cable at the burial plow entry point is abnormal. If it is abnormal, it sends an abnormal signal to the alarm unit 34. If it is normal, it inputs the submarine cable attitude image into the length prediction unit 35.

[0083] Alarm unit 34 is used to trigger an alarm when an abnormal signal is received;

[0084] The length prediction unit 35 is used to identify the length of the submarine cable at the point where the burial plow enters the plow mouth based on the submarine cable attitude image.

[0085] like Figure 4 As shown, the 3D reconstruction unit 31 includes an image preprocessing subunit 311, a 3D reconstruction subunit 312, a change law acquisition subunit 313, and a pose image correction subunit 314;

[0086] The image preprocessing subunit 311 is used to preprocess sonar images and camera images;

[0087] The 3D reconstruction subunit 312 is used to perform 3D reconstruction of the submarine cable outline and submarine cable region at the current acquisition time and the N+1 pairs of the N times before the current acquisition time, combined with the size parameters of the submarine cable, to obtain N+1 submarine cable reconstruction images.

[0088] The variation law acquisition subunit 313 is used to acquire the attitude variation law of the submarine cable based on the reconstructed image of N+1 submarine cables;

[0089] The attitude image correction subunit 314 is used to correct the submarine cable reconstructed image at the next sampling time according to the submarine cable attitude change law, so as to obtain the submarine cable attitude image used as input to the submarine cable state recognition unit 32.

[0090] The submarine cable status determination unit 33 is also used to transmit submarine cable fault status information to the cable laying control end when sending an abnormal signal to the alarm unit 34. Similar to Embodiment 1, refer to... Figure 2 Both the dual-frequency sonar 1 and the turbid water camera 2 are fixedly installed on the burial plow. The detection range of the dual-frequency sonar 1 and the shooting range of the turbid water camera 2 remain fixed relative to the burial plow.

[0091] Based on the detection range of dual-frequency sonar 1 and the shooting range of turbid water camera 2, a three-dimensional local space for burying the plow into the plow mouth is determined. During the three-dimensional reconstruction, only the submarine cable within the local space for burying the plow into the plow mouth is reconstructed in three dimensions.

[0092] Dual-frequency sonar 1 is located at the upper left of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening; turbid water camera 2 is located at the upper right of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening.

[0093] To enable rapid calculation, the length prediction module 3 is directly installed on the laying plow, and the predicted length is then sent to the cable-laying vessel via a signal cable.

[0094] This system corresponds to the method shown in Example 1 and can achieve the same effect.

[0095] Example 3

[0096] This embodiment provides a method for controlling the length of the submarine cable embedded in the plowshare, such as... Figure 5 As shown in the flowchart, the method includes the following steps:

[0097] A1. The length of the submarine cable buried in the plow mouth is obtained by the method of measuring the length of the submarine cable buried in the plow mouth as shown in Example 1 or the system of measuring the length of the submarine cable buried in the plow mouth as shown in Example 2, and is denoted as γ2.

[0098] A2. Subtract the measured cable length γ2 from the preset cable length γ1 to obtain the difference Δγ = γ2 - γ1;

[0099] A3. Combining Δγ with the speed of the cable-laying vessel and the speed of the burying plow, adjust the cable-laying speed and return to step A1 to remeasure the adjusted cable length, forming a closed-loop control until γ2 = γ1.

[0100] Specifically, in step A3, when Δγ>0, it means that the submarine cable is too long. The amount of reduction in cable laying speed is determined based on the speed difference between the current ship speed and the burial plow speed. When Δγ<0, it means that the submarine cable is too short. The amount of increase in cable laying speed is determined based on the speed difference between the current ship speed and the burial plow speed.

[0101] If step A1 fails to measure the length γ2 of the submarine cable within the local space of the plough cut but obtains information on the cable fault status, and cable laying needs to be suspended in order to clear the fault, then the length control method further includes the following steps:

[0102] The cable laying speed is controlled at 0, the burying plow speed is controlled at 0, and the speed of the cable ship is controlled at 0.

[0103] The cable length control method at the burial plow entry point provided by this invention adjusts the cable-laying speed of the cable-laying vessel in real time based on the predicted cable length at the burial plow entry point. This ensures that the cable length at the burial plow entry point remains constant during laying in complex seabed environments, and also ensures that the cable tension at the burial plow entry point remains constant during laying in complex seabed environments. This guarantees that the cable enters the burial plow with a relatively ideal tension state, thereby protecting the cable from mechanical damage due to excessive tension or twisting due to insufficient tension.

[0104] Example 4

[0105] This embodiment provides a control system for the length of the submarine cable buried in the plowshare, such as... Figure 6 The structural diagram shows that it includes a length measurement module 4, a length comparison module 5, and a speed control module 6.

[0106] The length measurement module 4 is used to obtain the length of the submarine cable within the local space of the buried plow in the plow mouth using the buried plow in the plow mouth length measurement method or the buried plow in the plow mouth length measurement system shown in Example 1, denoted as γ2.

[0107] The length comparison module 5 is used to calculate the difference between the measured submarine cable length γ2 and the preset value of submarine cable length γ1, and obtain the difference Δγ = γ2 - γ1.

[0108] Speed ​​control module 6 is used to combine Δγ with the speed of the cable ship and the speed of the burying plow, adjust the cable laying speed and then return to step A1 to remeasure the adjusted cable length, forming a closed-loop control until γ2 = γ1.

[0109] If the length measurement module 4 fails to measure the length γ2 of the submarine cable within the local space of the burial plow and instead obtains information about the submarine cable fault status, the speed control module 6 is also used to control the cable laying speed to 0, the burial plow speed to 0, and the submarine cable ship speed to 0.

[0110] This system corresponds to the method shown in Example 3 and can achieve the same effect.

[0111] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for measuring the length of a submarine cable embedded in the plough's mouth, characterized in that, Including the following steps: S1. Use dual-frequency sonar (1) to detect the sonar image at the point where the plow enters the plow mouth, and use a turbid water camera (2) to take a camera image at the point where the plow enters the plow mouth. S2. Based on the sonar image, the camera image, and the size parameters of the submarine cable, perform three-dimensional reconstruction of the submarine cable at the burial point of the plow to obtain the attitude image of the submarine cable. S3. Input the submarine cable attitude image into the submarine cable working state recognition model based on neural network to obtain the working state of the submarine cable at the burial plow entry point. S4. Determine if the working status of the submarine cable at the plow entry point is abnormal. If it is abnormal, an alarm will be triggered directly. If it is normal, proceed to step S5. S5. Identify the length of the submarine cable at the point where it enters the plowshare based on the submarine cable attitude image. Step S2 specifically includes the following steps: S21. After preprocessing the sonar image, extract the outline of the submarine cable in the sonar image; after preprocessing the camera image, crop the submarine cable area in the camera image. S22. Perform three-dimensional reconstruction of the submarine cable outline and submarine cable region at the current acquisition time and the N+1 pairs of the N previous acquisition times, combined with the size parameters of the submarine cable, to obtain N+1 reconstructed images of the submarine cable. S23. Based on the observation of the cable attitude change pattern in the N+1 reconstructed images, predict the cable attitude at the next sampling time. S24. Based on the predicted cable attitude at the next sampling time, the reconstructed cable image at the next sampling time is corrected to obtain the cable attitude image. The dual-frequency sonar (1) and the turbid water camera (2) are both fixedly installed on the burial plow. The detection range of the dual-frequency sonar (1) and the shooting range of the turbid water camera (2) are fixed relative to the burial plow. During the three-dimensional reconstruction, the local space of the buried plowshare is first determined based on the detection range of the dual-frequency sonar (1) and the shooting range of the turbid water camera (2), and then the three-dimensional reconstruction is performed only on the submarine cable within the local space of the buried plowshare. The dual-frequency sonar (1) is located at the upper left of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening; the turbid water camera (2) is located at the upper right of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening.

2. The method for measuring the length of a submarine cable buried in the plough's mouth according to claim 1, characterized in that, In step S4, when the working state is abnormal and an alarm is triggered, the submarine cable fault status information is also transmitted to the cable laying control terminal.

3. A system for measuring the length of a submarine cable embedded in the plough's mouth, characterized in that: It includes a dual-frequency sonar (1), a turbid water camera (2), and a length prediction module (3); the length prediction module (3) includes a three-dimensional reconstruction unit (31), a submarine cable status identification unit (32), a submarine cable status determination unit (33), an alarm unit (34), and a length prediction unit (35). The dual-frequency sonar (1) is used to perform sonar detection at the burial plow entry point to obtain sonar images and input them into the three-dimensional reconstruction unit (31). The turbid water camera (2) is used to capture camera images at the point where the plow enters the plow mouth and input them into the three-dimensional reconstruction unit (31). The three-dimensional reconstruction unit (31) is used to perform three-dimensional reconstruction of the submarine cable at the burial plow mouth based on the sonar image, the camera image and the size parameters of the submarine cable, to obtain the submarine cable attitude image and input it into the submarine cable state recognition unit (32). The submarine cable status recognition unit (32) is used to input the submarine cable attitude image into the submarine cable working status recognition model based on neural network to obtain the working status of the submarine cable at the burial plow entry point. The submarine cable status determination unit (33) is used to determine whether the working status of the submarine cable at the burial plow entry point is abnormal. If it is abnormal, it sends an abnormal signal to the alarm unit (34). If it is normal, it inputs the submarine cable attitude image into the length prediction unit (35). The alarm unit (34) is used to trigger an alarm when an abnormal signal is received; The length prediction unit (35) is used to identify the length of the submarine cable at the burial plow entry point based on the submarine cable attitude image. The three-dimensional reconstruction unit (31) includes an image preprocessing subunit (311), a three-dimensional reconstruction subunit (312), a change law acquisition subunit (313), and a pose image correction subunit (314). The image preprocessing subunit (311) is used to preprocess the sonar image and the camera image; The three-dimensional reconstruction subunit (312) is used to perform three-dimensional reconstruction of the submarine cable outline and submarine cable region at the current acquisition time and N+1 times before the current acquisition time, combined with the size parameters of the submarine cable, to obtain N+1 submarine cable reconstruction images. The change pattern acquisition subunit (313) is used to acquire the attitude change pattern of the submarine cable based on the reconstructed images of N+1 submarine cables. The attitude image correction subunit (314) is used to correct the submarine cable reconstructed image at the next sampling time according to the submarine cable attitude change law, so as to obtain the submarine cable attitude image. The dual-frequency sonar (1) and the turbid water camera (2) are both fixedly installed on the burial plow. The detection range of the dual-frequency sonar (1) and the shooting range of the turbid water camera (2) are fixed relative to the burial plow. Based on the detection range of the dual-frequency sonar (1) and the shooting range of the turbid water camera (2), a three-dimensional local space for burying the plow into the plow mouth is determined. During the three-dimensional reconstruction, only the submarine cable within the local space for burying the plow into the plow mouth is reconstructed in three dimensions. The dual-frequency sonar (1) is located at the upper left of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening; the turbid water camera (2) is located at the upper right of the local space where the plow enters the plow opening, directly facing the local space where the plow enters the plow opening.

4. The system for measuring the length of a submarine cable buried in the plough's mouth according to claim 3, characterized in that: The submarine cable status determination unit (33) is also used to transmit submarine cable fault status information to the cable laying control terminal when sending an abnormal signal to the alarm unit (34).

5. A method for controlling the length of submarine cable buried in the plowshare, characterized in that, Including the following steps: A1. The length of the submarine cable buried in the plowshare opening is obtained using the method for measuring the length of the submarine cable buried in the plowshare opening as described in claim 1 or 2, or the system for measuring the length of the submarine cable buried in the plowshare opening as described in claim 3 or 4, and recorded as . ; A2. The measured length of the submarine cable With the preset value of submarine cable length Take the difference to get the difference value. ; A3, Combination In addition to the speed of the cable-laying vessel and the speed of the laying plow, after adjusting the cable-laying speed, the process returns to step A1 to remeasure the adjusted cable length, forming a closed-loop control until... = .

6. The method for controlling the length of submarine cable buried in the plowshare according to claim 5, characterized in that: When step A1 fails to measure the length of the submarine cable buried within the local space of the plowshare, Instead, if the fault status information of the submarine cable is obtained, then the length control method also includes the following steps: The cable laying speed is controlled at 0, the burying plow speed is controlled at 0, and the speed of the cable ship is controlled at 0.

7. A control system for the length of a submarine cable buried in the plough's mouth, characterized in that: Includes a length measurement module (4), a length comparison module (5), and a speed control module (6); The length measurement module (4) is used to obtain the length of the submarine cable within the local space of the buried plowshare using the method for measuring the length of the buried plowshare submarine cable as described in claim 1 or 2, or the system for measuring the length of the buried plowshare submarine cable as described in claim 3 or 4. ; The length comparison module (5) is used to compare the measured length of the submarine cable. With the preset value of submarine cable length Take the difference to get the difference value. ; The speed control module (6) is used to combine In addition to the speed of the cable-laying vessel and the speed of the laying plow, after adjusting the cable-laying speed, the process returns to step A1 to remeasure the adjusted cable length, forming a closed-loop control until... = ; When the length measurement module (4) fails to measure the length of the submarine cable buried in the local space of the plowshare, Instead, if the fault status information of the submarine cable is obtained, the speed control module (6) is also used to control the cable laying speed to be 0, the burying plow speed to be 0, and the submarine cable ship speed to be 0.

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