A method and device for controlling the pay-off tension in cable construction and maintenance

Abstract

The application discloses a pay-off tension control method and device for cable construction and maintenance, and belongs to the technical field of submarine cables. The method comprises the following steps: collecting dynamic tension data of the submarine cable and performing filtering processing to obtain an effective tension signal; scanning an offshore external device, determining an ocean operation scene according to an in-situ state, and matching corresponding ocean tension threshold values and PID control parameters; adopting an ocean working condition improved PID algorithm, dynamically correcting proportional coefficients, integral coefficients and differential coefficients according to the operation scene, current level and operation depth, calculating a control amount and outputting a control instruction; adjusting a pay-off speed and a braking force according to the control instruction and a corresponding working mode to realize closed-loop constant tension control; and comparing the effective tension signal with the ocean tension threshold values to trigger a graded early warning. The application supports multi-device cooperative linkage, has the functions of graded early warning and data tracing, and significantly improves the safety and efficiency of submarine cable laying and maintenance operations.

Description

Technical Field

[0001] This invention belongs to the field of submarine cable technology, specifically relating to a method and device for controlling the tension of cable laying during cable construction and maintenance. Background Technology

[0002] In the construction and subsequent maintenance of submarine power cables and submarine communication optical cables, precise control of cable tension directly determines the quality of cable laying, the effectiveness of underwater maintenance, and the safety of offshore operations. The marine construction environment is complex, with external interferences such as wave disturbances, tidal fluctuations, ocean currents, and ship swaying. Submarine cables are far more sensitive to tension than land-based cables; abnormal tension can easily cause irreversible damage such as cable armor breakage, PE anti-corrosion sheath damage, seawater penetration into the insulation layer, cable loosening and entanglement, and abrasion from dragging on the seabed.

[0003] Currently, the industry mainly uses manual adjustment or simple mechanical control modes for tension control during submarine cable laying, resulting in low automation and numerous technical defects: insufficient tension control accuracy, unable to offset tension fluctuations caused by ocean disturbances; independent operation of offshore construction equipment modules, with no coordinated linkage between the laying device and underwater anchoring, submarine cable inspection, joint sealing maintenance, etc., making maintenance operations prone to underwater cable displacement and large inspection errors; poor scenario adaptability, unable to flexibly switch control modes according to working conditions such as offshore laying, underwater anchoring, and deep-sea inspection; lack of seawater corrosion-resistant monitoring and early warning mechanisms, making it difficult to capture tension anomalies caused by ocean disturbances in real time, resulting in extremely high risks in offshore operations.

[0004] Therefore, there is an urgent need for a submarine cable tension control device that is adaptable to complex marine working conditions, has multi-scenario coordination capabilities, and adaptive adjustment capabilities. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and device for controlling the tension of cable laying during cable construction and maintenance, so as to solve the problems of low tension control accuracy, weak anti-marine interference capability, lack of equipment coordination, poor scene adaptability, insufficient intelligence and lack of marine early warning and traceability mechanism in the prior art.

[0006] To achieve the above objectives, the present invention employs the following technical solution: A method for controlling cable tension during cable installation and maintenance includes: S1: Collect dynamic tension data of the submarine cable, filter the collected data to remove instantaneous disturbance data, and obtain the effective tension signal; S2, scan the external equipment at sea, determine the marine operation scenario based on the on-site status of the external equipment, match the corresponding marine tension threshold and PID control parameters; adopt the marine working condition improved PID algorithm, dynamically correct the proportional coefficient, integral coefficient and derivative coefficient according to the marine operation scenario, ocean current level and operation depth, calculate the control quantity and output the control command; S3, according to the control command and the working mode corresponding to the marine operation scenario, adjust the line laying speed and braking force to achieve closed-loop constant tension control; S4. Compare the effective tension signal with the ocean tension threshold to trigger a graded early warning.

[0007] A further improvement of the present invention is that: Preferably, the determination of the marine operation scenario in S2 includes: if the anchoring linkage interface is detected to be valid, it is determined to be a deep-sea anchoring maintenance scenario; if the detection linkage interface is detected to be valid, it is determined to be an insulation sheath detection scenario; if the sealing linkage interface is detected to be valid, it is determined to be a submarine cable PE anti-corrosion sheath repair mode; if no external equipment is valid, it is determined to be a near-shore conventional laying scenario.

[0008] Preferably, in the deep-sea anchoring maintenance scenario, the proportional coefficient is taken as 0.5 times the base value, the integral coefficient is taken as 3.0 times the base value, and the differential coefficient remains unchanged; the target tension is set to 5-15kN, and the control accuracy requires dynamic fluctuation not to exceed ±0.1kN and steady-state static error not to exceed ±0.05kN.

[0009] Preferably, in the insulation sheath testing scenario, the proportional coefficient is taken as 2.0 times the base value, the integral coefficient is taken as 0.2 times the base value, and the differential coefficient is taken as 2.5 times the base value; the target tension is set to 1-5kN, and the control accuracy is ±0.05kN.

[0010] Preferably, in the submarine cable PE anti-corrosion sheath repair mode, the proportional coefficient is 0.8 times the basic value, the integral coefficient is 0.5 times the basic value, and the differential coefficient is 4.0 times the basic value.

[0011] Preferably, in the near-shore conventional laying scenario, the proportional coefficient, the integral coefficient, and the differential coefficient all adopt basic values; the target tension is set to 10-30kN, and the control accuracy is ±0.2kN.

[0012] Preferably, the graded warning in S4 includes: Level 1 warning, which triggers an interface warning when the actual tension deviates from the target tension by ±5%; Level 2 warning, which triggers automatic deceleration and audible and visual alarms when the actual tension deviates from the target tension by ±10%; and Level 3 warning, which triggers emergency locking and braking when the actual tension deviates from the target tension by ±15%.

[0013] Preferably, S4 also includes a recording process, which records the cable laying depth, tension curve, ocean current data, and equipment linkage records to generate a marine construction traceability report.

[0014] A cable tension control device for cable construction and maintenance includes: The tension detection module is used to collect dynamic tension data of submarine cables, filter the collected data to remove instantaneous disturbance data, and obtain effective tension signals. The control module is used to scan external marine equipment, determine the marine operation scenario based on the on-site status of the external equipment, match the corresponding marine tension threshold and PID control parameters; adopt the marine working condition improved PID algorithm, dynamically correct the proportional coefficient, integral coefficient and derivative coefficient according to the marine operation scenario, ocean current level and operation depth, calculate the control quantity and output control command; The execution module is used to adjust the line-laying speed and braking force according to the control command and the working mode corresponding to the marine operation scenario to achieve closed-loop constant tension control. The early warning module is used to compare the effective tension signal with the ocean tension threshold and trigger a graded early warning.

[0015] Preferably, it also includes an auxiliary linkage module, including a waterproof linkage interface, which includes an anchoring linkage interface, a detection linkage interface, and a sealing linkage interface.

[0016] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a tension control method for cable laying during construction and maintenance. It aims to adapt to various construction and maintenance conditions of submarine cables in nearshore, offshore, and deep-sea environments, achieving adaptive tension adjustment, coordinated operation of multiple offshore equipment, tiered safety early warning, and traceability of operational data quality. This fills the technological gap in intelligent tension control equipment for deep-sea submarine cables. The invention incorporates four marine-specific strategies: nearshore laying, deep-sea anchoring, underwater detection, and sheath repair. It can automatically switch between operating conditions and is compatible with various submarine cable types, including high-voltage power cables, communication optical cables, and armored deep-sea cables. During tension control, a marine adaptive PID algorithm is employed, achieving a maximum control accuracy of ±0.05kN. This algorithm can counteract interference from waves, ocean currents, and ship swaying, preventing cable armor breakage, anti-corrosion sheath damage, and insulation layer water seepage, significantly extending the underwater service life of submarine cables. The invention employs a waterproof, audible, and visual three-level early warning system, which can quickly identify dangerous conditions such as sudden tension changes and excessive ocean currents, enabling emergency braking and cable locking to prevent safety accidents such as cable breakage and shipwrecks at sea.

[0017] Furthermore, this invention is compatible with marine-specific equipment such as underwater anchoring, flaw detection, and joint sealing. It can maintain operational synchronization with related equipment, and the submarine cable does not shift underwater during operation. This significantly reduces detection errors, improves offshore operation efficiency by more than 30%, reduces offshore construction time, and lowers marine construction costs. Attached Figure Description

[0018] Figure 1 This is a flowchart of the cable laying tension control method for cable construction and maintenance according to the present invention; Figure 2 This is a block diagram of the cable tension control device for cable construction and maintenance according to the present invention. Detailed Implementation

[0019] Hereinafter, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of that feature.

[0020] The method provided in this application can be applied to mobile phones, tablets, wearable devices, in-vehicle devices, augmented reality (AR) / virtual reality (VR) devices, laptops, and ultra-mobile personal computers. In this application, the specific type of terminal device is not limited to terminal devices such as mobile personal computers (UMPCs), netbooks, and personal digital assistants (PDAs).

[0021] It should be noted that the terms "first," "second," etc., used in the specification and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] See Figure 1 The first aspect of this invention discloses a method for controlling the tension of cable laying during cable construction and maintenance, the method comprising the following steps: S1 collects the dynamic tension of the submarine cable, filters out sea wave clutter, removes instantaneous disturbance data, and transmits the effective tension signal to the PLC.

[0023] S2. Select the marine tension threshold according to different marine operation scenarios. The marine operation scenarios include: if the anchoring linkage interface is valid, it indicates that an underwater anchoring mechanism is connected, and it is determined to be a deep-sea anchoring maintenance mode; if the detection linkage interface is valid, it indicates that a flaw detection instrument or insulation withstand voltage tester is connected, and it is determined to be an insulation sheath detection mode; if the sealing linkage interface is valid, it indicates that an underwater repair robot or sheath repair tool is connected, and it is determined to be a submarine cable PE anti-corrosion sheath repair mode; if no external equipment is valid, it is determined to be a near-shore conventional laying mode; the submarine cable diameter, armor material, and seawater depth can also be manually entered to automatically match the marine tension threshold.

[0024] Different marine operation scenarios require different preset cable tensions, control precision, PID correction coefficients, and auxiliary linkage logic.

[0025] Based on different marine operation scenarios, corresponding marine PID adaptive tension adjustment is implemented, employing a marine condition-modified PID algorithm. The proportional coefficient, integral coefficient, and derivative coefficient are dynamically adjusted according to ocean current level and operating depth. Algorithm formula: ; in,

[0026]

[0027]

[0028] in, This is the proportionality coefficient. The integral coefficient is... α, β, and γ are differential coefficients, and α, β, and γ are correction coefficients for the marine scene to suppress low-frequency disturbances at sea.

[0029] When the auxiliary linkage module detects a valid connection between the anchoring linkage interface and the underwater hydraulic anchoring mechanism, the control module automatically identifies the current operating scenario as deep-sea anchoring maintenance mode. In this mode, a static tension holding strategy is adopted, with the system setting the target tension to 5–15 kN (typical value 10 kN). The control accuracy requirement is that dynamic fluctuations do not exceed ±0.1 kN, and steady-state static error does not exceed ±0.05 kN. The control module calls the static holding PID parameters: the proportional coefficient Kp is taken as 0.5 times the base value, the integral coefficient Ki is taken as 3.0 times the base value, and the derivative coefficient Kd remains unchanged. This enhances the integral action to eliminate low-frequency drift caused by ocean currents and tides, while simultaneously reducing the proportional gain to avoid overshoot.

[0030] When the auxiliary linkage module detects that the detection linkage interface has established a valid connection with the submarine cable insulation withstand voltage tester or the anti-corrosion sheath flaw detector, the control module automatically switches to the insulation sheath detection mode. In this mode, a micro-tension precision sampling strategy is adopted, with the target tension set at 1–5 kN (typical value 2 kN), improving the control accuracy to ±0.05 kN. A high proportional gain, strong derivative, and weak integral PID correction scheme is used: the proportional coefficient Kp is 2.0 times the base value, the integral coefficient Ki is 0.2 times the base value, and the derivative coefficient Kd is 2.5 times the base value. The high proportional gain enables rapid response to small deviations, the strong derivative effect suppresses high-frequency noise such as hull swaying and seawater fluctuations, and the weak integral prevents integral saturation and overshoot. Simultaneously, the system automatically calculates the buoyancy force on the cable body based on the current water depth and seawater density, superimposing the buoyancy compensation value onto the target tension, making the actual physical force on the submarine cable body approach zero, eliminating the interference of tension on detection parameters such as insulation resistance and partial discharge.

[0031] When the auxiliary linkage module detects that the sealed linkage interface has established a connection with the underwater repair robot or diver's communication terminal and receives a request for the repair mode of the submarine cable's PE anti-corrosion sheath, it automatically enters the dynamic disturbance compensation mode. This mode does not target fixed tension, but rather uses zero relative velocity between the cable and the repair tool as the core control objective, with tension serving as an auxiliary constraint. The control module incorporates real-time signals from the ship's motion sensor (IMU) or ocean current velocity meter to calculate the expected cable displacement velocity, and superimposes it onto the line-laying speed command in a feedforward manner: that is, the line-laying speed command value equals the estimated cable disturbance velocity plus the PID tension deviation adjustment. The PID parameters are configured as follows: the proportional coefficient Kp is 0.8 times the base value, the integral coefficient Ki is 0.5 times the base value, and the derivative coefficient Kd is 4.0 times the base value. Strong derivative action provides a rapid response to the rate of change of disturbance, while the integral action is appropriately weakened to prevent excessive accumulation during dynamic tracking.

[0032] When all auxiliary linkage interfaces are not effectively connected and the operator does not manually specify a special mode, the control module defaults to the near-shore conventional laying mode. The target tension in this mode is set to 10–30 kN (typical value 18 kN), with a control accuracy of ±0.2 kN. The PID parameters use the base values: Kp, Ki, and Kd are the base values. Advanced functions such as buoyancy compensation, feedforward control, and notch filtering are not enabled.

[0033] S3 enables multiple devices at sea to work together in different marine operation scenarios.

[0034] In the deep-sea anchoring maintenance mode, a static constant tension is maintained in conjunction with underwater anchoring locking. The hydraulic brake in the execution module enters a pressure-holding mode, maintaining approximately 30% of the basic braking force, and finely adjusting the pressure within ±10% based on the PID output to resist low-frequency tension drift caused by ocean currents and tides. The variable frequency motor mainly operates in low-speed stall torque mode, only briefly rotating forward to replenish the cable when the tension drops above a threshold. When the actual tension remains stable within ±0.1 kN of the target value for 10 consecutive seconds, the control module outputs a pressure-holding ready signal to the anchoring linkage interface, allowing the underwater hydraulic mechanism to perform the locking action. During the anchoring locking process, the execution module maintains the current braking force unchanged until it receives a withdrawal command from the control module.

[0035] In the insulation sheath detection mode, a low tension is maintained to eliminate the interference of seawater buoyancy on detection accuracy. Specifically, in the execution module, the brake is fully released, and the wire-laying motor outputs only a low-friction traction force of 0-5% of its rated torque. When the detection instrument sends a sampling signal, the PID adjustment cycle is shortened to 10 milliseconds to quickly respond to minute tension fluctuations. If the tension deviates from the target value by more than ±0.1kN, the execution module compensates by fine-tuning the motor torque in steps not exceeding 0.5% of the rated torque, while the brake remains released.

[0036] In the PE anti-corrosion sheath repair mode for submarine cables, the execution module enters a dynamic following mode; the sheath repair scenario dynamically compensates for ocean current disturbances to ensure repair fit. During this process, the variable frequency motor allows frequent switching between forward and reverse rotation, with a motor response time of no more than 100 milliseconds, to achieve real-time compensation for ocean current disturbances and hull sway; the execution module drives the motor according to the line speed set by the PID controller, making the relative speed between the cable and the underwater repair tool approach zero, and the brake is fully released under normal operating conditions, serving only as a safety backup.

[0037] If no external equipment is effective, the installation is determined to be in the standard near-shore laying mode, corresponding to the standard tension control strategy. This mode sets the target tension to 10–30 kN (typical value 18 kN) with a control accuracy of ±0.2 kN. The PID parameters use the base values: Kp, Ki, and Kd are the base values. Advanced functions such as buoyancy compensation, feedforward control, and notch filtering are not enabled.

[0038] In manual linkage mode, the braking mechanism uses a mechanical anti-corrosion brake instead of a hydraulic brake. The speed of the wire feeding motor is manually adjusted by the operator through a handheld control box or touch screen, and is continuously adjustable from 0 to 100%. Adaptive PID closed-loop control is not enabled.

[0039] In some embodiments of the present invention, an early warning step is also included. In S2, while collecting the effective tension, it is determined whether the effective tension exceeds the threshold of different marine operation scenarios. If it exceeds the threshold, a three-level tiered early warning is set according to the level of exceedance. The first-level early warning is a tension deviation of ±5%, which is displayed on the touch screen interface of the control module. The second-level early warning is a tension deviation of ±10%, which triggers automatic deceleration and a high-decibel audible and visual alarm at sea. The third-level early warning is a tension deviation of ±15%, which triggers emergency locking and braking to prevent the submarine cable from breaking.

[0040] It also includes recording the entire process, including the laying depth of the submarine cable, tension curves, ocean current data, and equipment linkage records, generating a marine construction traceability report to meet the acceptance standards for offshore wind power and submarine communication projects.

[0041] See Figure 2 The second aspect of the present invention discloses a cable tension control device for cable construction and maintenance, comprising: Tension detection module 1, installed at the cable outlet of the offshore cable laying frame, adopts a marine-resistant, sealed encapsulation structure. A high-precision tension sensor is preferred, with a range of 0~30kN and an accuracy of ±0.1kN, resistant to seawater corrosion; an alternative is a force sensor, with a range of 0~50kN and an accuracy of ±0.2kN, suitable for simple near-shore optical cable installation. This module collects dynamic tension data of the submarine cable in real time, filters it to resist wave interference, and then transmits it to the control module.

[0042] Control module 2 uses a Siemens S7-1200 marine-specific anti-corrosion PLC as its control core, and integrates a scene recognition unit, an adaptive PID control unit, an early warning unit, and an industrial communication unit. The module has a pre-built library of four types of marine-specific scene control strategies: a static tension holding strategy for deep-sea anchoring maintenance mode, a micro-tension precision sampling strategy for insulation sheath detection mode, a dynamic disturbance compensation strategy for submarine cable PE anti-corrosion sheath repair mode, and a standard tension control strategy for near-shore conventional laying. This control module 2 can automatically identify the status of external equipment at sea, intelligently match control parameters, and achieve time synchronization of multiple devices at sea via the EtherCAT industrial bus, resisting salt spray electromagnetic interference.

[0043] Execution module 3 includes a marine-grade braking mechanism and a marine corrosion-resistant heavy-duty cable laying frame. The marine corrosion-resistant heavy-duty cable laying frame includes a variable frequency motor drive system and a bidirectional guiding cable laying mechanism. The dual-guide structure for both inlet and outlet lines suppresses cable deviation and sway, making it suitable for large-diameter, heavily armored high-voltage submarine cables. The corrosion-resistant heavy-duty cable laying frame provides active cable laying power, while the braking mechanism provides braking force. Control module 2 outputs speed adjustment commands to the variable frequency motor drive system and braking force adjustment commands to the braking mechanism based on tension deviation; the two work together to control the cable tension.

[0044] Among them, the marine-grade braking mechanism preferably uses hydraulic braking, which has high braking force, is resistant to sea wind vibration, and is suitable for heavy-load submarine cable laying; alternative solutions are electromagnetic braking, which is suitable for high-speed near-shore laying, and mechanical braking, which is suitable for severe stormy sea conditions; the execution module receives control commands, adjusts the cable laying speed and braking force, and counteracts the tension disturbances caused by ocean currents and ship swaying to achieve closed-loop constant tension control.

[0045] Auxiliary linkage module 4 includes three types of waterproof linkage interfaces: ① Anchoring linkage interface: connects to the underwater hydraulic anchoring and fastening mechanism to achieve underwater positioning and pressure maintenance of the submarine cable; ② Detection linkage interface: connects to the submarine cable insulation withstand voltage tester and the anti-corrosion sheath flaw detection equipment; ③ Sealing linkage interface: connects to the submarine cable joint box underwater sealing maintenance equipment; and realizes coordinated timing control of all offshore operating equipment.

[0046] The early warning module 5 is electrically connected to the control module and adopts a marine waterproof audible and visual alarm structure. It is equipped with a three-level layered early warning system: the first level early warning is a tension deviation of ±5%, which is operated by a touch screen interface warning; the second level early warning is a tension deviation of ±10%, which is operated by automatic deceleration and a high-decibel audible and visual alarm at sea; the third level early warning is a tension deviation of ±15%, which is operated by emergency locking and braking to prevent the submarine cable from breaking.

[0047] The cable guide module 6, serving as an auxiliary mechanism to the bidirectional cable laying mechanism, is positioned along the laying path before the cable exit, turning point, and water entry point of the heavy-duty anti-corrosion cable laying frame. It employs arc-shaped anti-corrosion guide wheels to limit cable offset, prevent dragging and wear on the armor layer at sea, and ensure the stability of the laying path. For example, the first guide wheel is mounted on the cable exit frame of the main body 6, with its rotation axis at a set angle to the tangent of the cable laying drum, used to smoothly guide the cable out of the drum. The second and subsequent guide wheels are sequentially mounted on guide wheel brackets on the ship's deck along the laying direction, with the installation position of each guide wheel adjusted according to the turning points and water entry points of the laying path. All guide wheel mounting brackets are fixed to the deck's embedded steel plates or the cable laying frame base with bolts, and their positions can be adjusted laterally and longitudinally. At the water entry point, a large-diameter arc-shaped guide wheel, such as ≥500mm, is installed as close as possible to the ship's side to reduce the cable's water entry angle and avoid friction with the ship's side.

[0048] The cable tension compensation module 7 is equipped with an elastic buffer compensation structure, specifically a spring sleeve and a damper, which is installed between the marine corrosion-resistant heavy cable laying frame and the tension detection module to automatically compensate for tension drift caused by the weight of the submarine cable, seawater buoyancy, and ocean current impact, thereby improving the stability of marine working conditions.

[0049] Submarine cable status monitoring module 8 collects data on cable laying speed, cable tension, ambient temperature and humidity, and salt spray concentration in real time to determine the laying status of the submarine cable.

[0050] The hardware of this invention is made entirely of marine-resistant materials, making it suitable for high-salt-spray, humid, and corrosive marine operating environments.

[0051] The following description, in conjunction with specific embodiments, provides further details.

[0052] Example 1 The project involved the laying and underwater joint maintenance of 110kV high-voltage armored submarine cables for an offshore wind farm. The work encompassed three marine conditions: nearshore laying, deep-sea underwater anchoring, and cable insulation withstand voltage testing. The ocean current level was 2-3, with high salt spray concentration. The system included: a tension detection module (corrosion-resistant high-precision tension sensor); a control module (Siemens S7-1200 marine-specific PLC); an execution module (marine hydraulic braking mechanism); an auxiliary linkage module (dual waterproof interfaces for underwater anchoring and insulation testing); a cable laying device (heavy-duty corrosion-resistant variable frequency cable laying frame); and additional tension compensation and cable condition monitoring modules.

[0053] The operation process based on the above-mentioned device includes: Step 1, Nearshore Laying Stage: The system determines that there is no external underwater equipment, matches the nearshore standard tension strategy, sets the tension to 18kN with an accuracy of ±0.2kN, and uses PID basic parameters to suppress minor wave disturbances, ensuring that the submarine cable is laid without dragging or wear.

[0054] Step 2, Deep-sea anchoring stage: Deploy the underwater anchoring device, and the system automatically switches to the deep-sea static pressure holding strategy, setting the tension to 10kN with an accuracy of ±0.1kN; optimize the PID integral parameters to improve the resistance to ocean currents, and control the tension fluctuation during the anchoring process within the allowable range to prevent underwater displacement of the submarine cable.

[0055] Step 3, Insulation Testing Stage: Connect the underwater insulation tester, switch to the micro-tension testing strategy, set the tension to 2.0kN, and the accuracy to ±0.05kN; use high-sensitivity PID to compensate for seawater buoyancy disturbances to ensure accurate insulation test data.

[0056] Step 4, Marine Operation Traceability: Automatically generate marine construction reports, record marine environment, laying depth, tension curve, and linkage status. This operation had no tension exceeding the standard, the project quality rating is A, and it meets the offshore wind power acceptance standards.

[0057] Example 2 Emergency repair of broken optical fiber cables in nearshore shallow waters is required due to the small waves and limited construction space. The equipment must be lightweight, corrosion-resistant, low-cost, and easy to transport. The system includes: Tension Detection Module 1 (corrosion-resistant tensile sensor); Control Module 2 (simple waterproof PLC); Actuation Module 3 (mechanical corrosion-resistant braking mechanism); and Auxiliary Linkage Module (single waterproof anchoring interface). Complex adaptive algorithms have been eliminated, simplifying the early warning structure. The system enables manual cable laying in nearshore waters with tension control accuracy of ±0.2kN. After laying, a simple underwater anchoring device is connected, and the linkage mode is manually triggered, maintaining static tension for underwater fixation. The device has a compact structure, is resistant to seawater corrosion, and is suitable for simple nearshore emergency repairs, significantly reducing offshore construction costs.

[0058] This invention relates to the fields of laying, construction, operation, and maintenance of submarine power cables and submarine communication optical cables. Specifically, it relates to a multi-scenario collaborative adaptive tension control method and device for submarine cable construction and maintenance. It is applicable to complex marine operation scenarios such as near-shore and offshore submarine cable laying, submarine optical cable traction and burial, underwater anchoring and maintenance of submarine cables, sealing and maintenance of submarine cable junction boxes, inspection and repair of submarine cable outer PE anti-corrosion sheaths, and insulation withstand voltage inspection and maintenance of submarine cables. This invention is applicable to the following scenarios: 1. Offshore high-voltage submarine cable laying: Applied to the traction and burial of submarine power cables for offshore wind power and nearshore power grids, precisely controlling tension to prevent damage to the armor layer due to dragging.

[0059] 2. Deep-sea communication optical cable construction: laying submarine communication optical cables in the open sea, compensating for seawater buoyancy and ocean current disturbances, and ensuring the straight laying of optical cables.

[0060] 3. Underwater anchoring maintenance: Repairing loose or misaligned underwater anchors of submarine cables, maintaining constant underwater static tension, and preventing submarine cables from drifting or shifting.

[0061] 4. Sealing and maintenance of submarine cable junction boxes: Underwater sealing operation of deep-sea junction boxes to stabilize cable tension and ensure that the sealant adheres without water leakage.

[0062] 5. PE anti-corrosion sheath inspection and repair: flaw detection and repair of the outer anti-corrosion layer of submarine cables, dynamically adapting to ocean current fluctuations to improve the fit of the repair.

[0063] 6. Submarine cable insulation withstand voltage test: underwater insulation testing and withstand voltage test, micro-tension stability control, elimination of environmental interference, and improvement of testing accuracy.

[0064] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0065] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0066] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for controlling the tension of cable laying during cable construction and maintenance, characterized in that, include: S1: Collect dynamic tension data of the submarine cable, filter the collected data to remove instantaneous disturbance data, and obtain the effective tension signal; S2, scan the external equipment at sea, determine the marine operation scenario based on the on-site status of the external equipment, match the corresponding marine tension threshold and PID control parameters; adopt the marine working condition improved PID algorithm, dynamically correct the proportional coefficient, integral coefficient and derivative coefficient according to the marine operation scenario, ocean current level and operation depth, calculate the control quantity and output the control command; S3, according to the control command and the working mode corresponding to the marine operation scenario, adjust the line laying speed and braking force to achieve closed-loop constant tension control; S4. Compare the effective tension signal with the ocean tension threshold to trigger a graded early warning.

2. The cable tension control method for cable construction and maintenance according to claim 1, characterized in that, The determination of marine operation scenarios described in S2 includes: if the anchoring linkage interface is detected as valid, it is determined to be a deep-sea anchoring maintenance scenario; if the detection linkage interface is detected as valid, it is determined to be an insulation sheath detection scenario; if the sealing linkage interface is detected as valid, it is determined to be a submarine cable PE anti-corrosion sheath repair mode; if no external equipment is valid, it is determined to be a near-shore conventional laying scenario.

3. A method for controlling the tension of cable laying during construction and maintenance according to claim 1 or 2, characterized in that, In the deep-sea anchoring maintenance scenario, the proportional coefficient is taken as 0.5 times the base value, the integral coefficient is taken as 3.0 times the base value, and the differential coefficient remains unchanged; The target tension is set to 5–15 kN, and the control accuracy requires dynamic fluctuations not to exceed ±0.1 kN and steady-state static error not to exceed ±0.05 kN.

4. A method for controlling cable tension during construction and maintenance according to claim 1 or 2, characterized in that, In the insulation sheath testing scenario, the proportional coefficient is taken as 2.0 times the base value, the integral coefficient is taken as 0.2 times the base value, and the differential coefficient is taken as 2.5 times the base value; the target tension is set to 1~5kN, and the control accuracy is ±0.05kN.

5. A method for controlling cable tension during construction and maintenance according to claim 1 or 2, characterized in that, In the submarine cable PE anti-corrosion sheath repair mode, the proportional coefficient is taken as 0.8 times the basic value, the integral coefficient is taken as 0.5 times the basic value, and the differential coefficient is taken as 4.0 times the basic value.

6. A method for controlling the tension of cable laying during construction and maintenance according to claim 1 or 2, characterized in that, In the aforementioned near-shore conventional laying scenario, the proportional coefficient, the integral coefficient, and the differential coefficient all adopt basic values; the target tension is set to 10–30 kN, and the control accuracy is ±0.2 kN.

7. The cable tension control method for cable construction and maintenance according to claim 1, characterized in that, The graded warning system described in S4 includes: Level 1 warning, which triggers an interface warning when the actual tension deviates from the target tension by ±5%; Level 2 warning, which triggers automatic deceleration and audible and visual alarms when the actual tension deviates from the target tension by ±10%; and Level 3 warning, which triggers emergency locking and braking when the actual tension deviates from the target tension by ±15%.

8. The cable tension control method for cable construction and maintenance according to claim 1, characterized in that, S4 also includes a recording process, which records the cable laying depth, tension curve, ocean current data, equipment linkage records, and generates a marine construction traceability report.

9. A cable tension control device for cable construction and maintenance, characterized in that, include: The tension detection module is used to collect dynamic tension data of submarine cables, filter the collected data to remove instantaneous disturbance data, and obtain effective tension signals. The control module is used to scan external marine equipment, determine the marine operation scenario based on the on-site status of the external equipment, match the corresponding marine tension threshold and PID control parameters; adopt the marine working condition improved PID algorithm, dynamically correct the proportional coefficient, integral coefficient and derivative coefficient according to the marine operation scenario, ocean current level and operation depth, calculate the control quantity and output control command; The execution module is used to adjust the line-laying speed and braking force according to the control command and the working mode corresponding to the marine operation scenario to achieve closed-loop tension control; The early warning module is used to compare the effective tension signal with the ocean tension threshold and trigger a graded early warning.

10. A cable tension control device for cable construction and maintenance according to claim 9, characterized in that, It also includes an auxiliary linkage module, including a waterproof linkage interface, which includes an anchoring linkage interface, a detection linkage interface, and a sealing linkage interface.

Images