Ship stabilization state evaluation method and system for submarine cable laying operation

Abstract

The application provides a ship anti-rolling state evaluation method and system for submarine cable laying operation, relates to the technical field of ship anti-rolling, and comprises the following steps: collecting ship motion state data, anti-rolling device operation state data, submarine cable tension data and current sea area environmental wave data in real time, calculating a ship anti-rolling safety margin index and a submarine cable tension safety margin index in real time, calculating a matching degree index of the ship anti-rolling safety margin index and the submarine cable tension safety margin index, evaluating a current anti-rolling state and generating a suspended section length adjustment instruction, and solving the technical problem that in the prior art, ship anti-rolling control and submarine cable tension control are independent of each other, lack of a cooperative evaluation and linkage adjustment mechanism, and imbalance risk is prone to occur. The matching degree index quantifies the balance degree of the anti-rolling capacity and the submarine cable tension safety level, realizes dynamic cooperative adjustment of the suspended section length, and improves the technical effects of safety and adjustment accuracy of submarine cable laying operation.

Description

Technical Field

[0001] This application relates to the field of ship roll reduction technology, specifically to a method and system for assessing ship roll reduction status for submarine cable laying operations. Background Technology

[0002] Submarine cable laying is a high-risk operation in marine engineering. When ships lay submarine cables in complex sea conditions, the hull is subjected to waves, resulting in multi-degree-of-freedom movements such as rolling and pitching, which directly affects the cable's attitude and landing accuracy. At the same time, the submarine cable is subjected to its own weight, water current drag, and dynamic tension generated by the coupling of the ship's motion during the laying process. If the tension exceeds the limit, it will lead to serious accidents such as deformation of the cable armor layer, core breakage, or even complete cable scrapping.

[0003] Currently, in existing technologies, ship roll reduction control and submarine cable tension monitoring are usually two independent processes. The roll reduction process independently decides to output torque to suppress hull rolling based on the ship's motion state, while the tension monitoring process independently judges whether the cable tension is close to the allowable limit based on the measured value. The lack of information exchange and collaborative evaluation mechanism between the two leads to a situation where, when sea conditions change abruptly, the roll reduction device may be operating at full load to suppress rolling, while the ship's violent motion applies additional dynamic tension to the cable. This ensures that each process is safe on its own, but creates a dynamic imbalance between roll reduction capacity and tension safety as a whole. That is, when one is close to the limit while the other still has a margin, the operational safety margin cannot be optimized collaboratively, and operators find it difficult to obtain a unified quantitative decision-making basis to judge the current operational status. This affects the accurate judgment of the timing and amount of adjustment of the suspended section length, which can easily lead to delayed or excessive adjustment, reducing operational efficiency and safety.

[0004] In summary, in existing submarine cable laying operations, ship roll reduction control and cable tension control are independent of each other, lacking a collaborative assessment and linkage adjustment mechanism. This leads to a technical problem where roll reduction capability and tension safety are difficult to dynamically match, and imbalance risks are likely to occur. Summary of the Invention

[0005] The purpose of this application is to provide a method and system for assessing the roll reduction status of ships used in submarine cable laying operations, in order to solve the technical problem that in existing submarine cable laying operations, ship roll reduction control and submarine cable tension control are independent of each other, lack a collaborative assessment and linkage adjustment mechanism, which makes it difficult to dynamically match roll reduction capacity and tension safety, and easily leads to the risk of imbalance.

[0006] To achieve the above objectives, this application provides a method and system for assessing the roll reduction status of vessels used in submarine cable laying operations.

[0007] In a first aspect, this application provides a method for assessing the roll reduction status of a vessel for submarine cable laying operations. The method includes: real-time acquisition of vessel motion status data, roll reduction device operation status data, submarine cable tension data, and current marine environmental wave data; real-time calculation of the vessel roll reduction safety margin index and the submarine cable tension safety margin index; calculation of the matching degree index between the vessel roll reduction safety margin index and the submarine cable tension safety margin index, wherein the matching degree index is used to characterize the degree of balance between the vessel's current roll reduction capability and the current tension safety level of the submarine cable; and assessment of the current roll reduction status based on the matching degree index and generation of a suspension section length adjustment command.

[0008] Optionally, the length of the suspended section refers to the length of the submarine cable suspended from the stern guide to the seabed landing point.

[0009] Optionally, the current output torque of the roll reduction device is obtained based on the operating status data of the roll reduction device, and operating condition matching is performed in combination with the ship motion status data and the current sea environment wave data to comprehensively determine the upper limit of the available capacity of the roll reduction device under the current operating condition; the ship roll reduction safety margin index is calculated based on the upper limit of the available capacity and the current output torque; the current real-time tension value is obtained based on the submarine cable tension data, and the allowable tension upper limit is determined based on the inherent parameters of the submarine cable and the current suspended section length; the submarine cable tension safety margin index is calculated based on the allowable tension upper limit and the current real-time tension value.

[0010] Optionally, the ship's current speed and attitude angle are extracted from the ship's motion state data; the current wave frequency and sea state level are extracted from the current sea environment wave data; real-time operating condition information is generated using the ship's current speed and attitude angle, the current wave frequency and sea state level; and the pre-built anti-roll device capability database is called for matching in combination with the current output torque and real-time operating condition information to obtain the upper limit of the available capability.

[0011] Optionally, the ship roll reduction safety margin index represents the proportion of the current output torque to the maximum available capacity determined based on the current available capacity upper limit; the submarine cable tension safety margin index represents the proportion of the current real-time tension value to the allowable tension upper limit.

[0012] Optionally, the ship roll reduction safety margin index and the submarine cable tension safety margin index are dimensionless, and the ratio between the dimensionless ship roll reduction safety margin index and the submarine cable tension safety margin index is calculated to obtain an initial matching degree index; the matching degree index is obtained according to the degree of deviation between the initial matching degree index and the preset ideal matching range.

[0013] Optionally, the preset ideal matching range is the interval defined by the upper and lower thresholds centered on the value 1; the degree and direction of deviation between the initial matching index and the preset ideal matching range are calculated to generate the matching index.

[0014] Optionally, based on the matching degree index, it is determined whether the ship's current roll reduction capability and the submarine cable's current tension safety level are in a balanced state; if not, based on the matching degree index and the deviation direction, the suspended section length adjustment parameter is matched in a preset balanced matching database; the suspended section length adjustment command is generated based on the suspended section length adjustment parameter.

[0015] Optionally, when generating the suspended section length adjustment command based on the suspended section length adjustment parameters, the adjustment is performed in stages according to the minimum adjustment step size, and the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index is recalculated after each adjustment, and the adjustment monitoring is performed based on the recalculation result.

[0016] Secondly, this application also provides a ship roll reduction status assessment system for submarine cable laying operations. The system includes: a data acquisition module for real-time acquisition of ship motion status data, roll reduction device operation status data, submarine cable tension data, and current marine environmental wave data, and for real-time calculation of ship roll reduction safety margin index and submarine cable tension safety margin index; a matching degree calculation module for calculating the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index, wherein the matching degree index characterizes the degree of balance between the ship's current roll reduction capability and the current tension safety level of the submarine cable; and a status assessment module for assessing the current roll reduction status based on the matching degree index and generating a suspension section length adjustment command.

[0017] One or more technical solutions provided in this application have at least the following technical effects or advantages: By collecting real-time data on ship motion status, anti-roll device operation status, submarine cable tension, and current marine environmental wave data, the ship anti-roll safety margin index and the submarine cable tension safety margin index are calculated in real time. A matching degree index between the ship anti-roll safety margin index and the submarine cable tension safety margin index is calculated. This matching degree index characterizes the balance between the ship's current anti-roll capability and the current cable tension safety level. Based on the matching degree index, the current anti-roll status is assessed, and an adjustment command for the length of the suspended section is generated. Ultimately, this achieves the technical effect of quantifying the balance between anti-roll capability and the cable tension safety level through the matching degree index, realizing dynamic and coordinated adjustment of the suspended section length, and improving the safety and adjustment accuracy of submarine cable deployment operations.

[0018] The above description is merely an overview of the technical solution of this application. To enable a clearer understanding of the technical means of this application and to facilitate its implementation according to the description, and to make the above and other objects, features, and advantages of this application more apparent, specific embodiments of this application are described below. It should be understood that the content described in this section is not intended to identify key or important features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent through the following description. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the method for assessing the ship roll reduction status used in submarine cable laying operations, as described in this application.

[0021] Figure 2 This is a schematic diagram of the equilibrium matching adjustment process in the ship roll reduction state assessment method used in this application for submarine cable laying operations.

[0022] Figure 3 This is a schematic diagram of the ship roll reduction status assessment system used in submarine cable laying operations according to this application.

[0023] Figure labeling: Data acquisition module 11, matching degree calculation module 12, status assessment module 13. Detailed Implementation

[0024] This application provides a method and system for assessing the roll reduction status of vessels used in submarine cable laying operations. It addresses the technical problem in existing submarine cable laying operations where vessel roll reduction control and cable tension control are independent, lacking a coordinated assessment and linkage adjustment mechanism. This leads to difficulties in dynamically matching roll reduction capacity and tension safety, resulting in a risk of imbalance. The method achieves the technical effect of quantifying the balance between roll reduction capacity and cable tension safety level through a matching degree index, enabling dynamic and coordinated adjustment of the suspended section length, and improving the safety and adjustment accuracy of submarine cable laying operations.

[0025] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. It should be understood that this application is not limited to the exemplary embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. It should also be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all of them.

[0026] Example 1, please refer to the appendix. Figure 1 This application provides a method for assessing the roll reduction status of a vessel for submarine cable laying operations, wherein the method specifically includes: Real-time data collection of ship motion status, anti-roll device operation status, submarine cable tension, and current marine environmental wave data; real-time calculation of ship anti-roll safety margin and submarine cable tension safety margin.

[0027] Furthermore, real-time data collection of ship motion status, anti-roll device operation status, submarine cable tension, and current marine environmental wave data is performed to calculate the ship anti-roll safety margin index and the submarine cable tension safety margin index. This includes: obtaining the current output torque of the anti-roll device based on the anti-roll device operation status data; performing operating condition matching in conjunction with the ship motion status data and the current marine environmental wave data to comprehensively determine the upper limit of the available capacity of the anti-roll device under the current operating condition; calculating the ship anti-roll safety margin index based on the upper limit of the available capacity and the current output torque; obtaining the current real-time tension value based on the submarine cable tension data; determining the upper limit of the allowable tension based on the inherent parameters of the submarine cable and the current suspended section length; and calculating the submarine cable tension safety margin index based on the upper limit of the allowable tension and the current real-time tension value.

[0028] Furthermore, the length of the suspended section refers to the length of the suspended section of the submarine cable from the stern guide to the seabed landing point.

[0029] Furthermore, the ship roll reduction safety margin index represents the proportion of the current output torque to the maximum available capacity determined based on the current available capacity upper limit; the submarine cable tension safety margin index represents the proportion of the current real-time tension value to the allowable tension upper limit.

[0030] Specifically, the ship's motion status data, anti-roll device operation status data, submarine cable tension data, and current marine environmental wave data are collected in real time by the ship's integrated monitoring system. The ship's motion status data includes attitude angles such as pitch, roll, and bow angles, as well as the ship's current ground speed, collected by a fiber optic compass and GPS / BeiDou integrated navigation system, with a sampling frequency of no less than 10Hz to ensure dynamic response accuracy. The anti-roll device operation status data includes the current output torque value of actuators such as anti-roll fins or anti-roll tanks, in kN·m, collected and output in real time by torque sensors inside the anti-roll controller. The submarine cable tension data is obtained through tension measuring pulleys or pin-type force sensors installed at the stern cable guide, outputting the current real-time tension value of the submarine cable in kN. The current marine environmental wave data includes the dominant wave frequency and sea state classification based on significant wave height, such as the Beaufort scale or the World Meteorological Organization standard, obtained in real time by wave radar or wave buoys mounted on the ship.

[0031] Then, the current output torque of the roll damping device is extracted from the operating status data of the device, and a working condition matching operation is performed: the current output torque is combined with the ship's motion state data and the current sea environment wave data, and a matching query is performed in a pre-built roll damping device capacity database. The roll damping device capacity database pre-stores the maximum available capacity upper limit of the roll damping device under different working condition combinations, that is, the maximum stable torque that the roll damping device can theoretically output under specific sea state, speed, and attitude conditions, thereby comprehensively determining the upper limit of the available capacity of the roll damping device under the current working condition. Based on the upper limit of available capacity and the current output torque, the ship's roll damping safety margin index is calculated, where the ship's roll damping safety margin index = current output torque / upper limit of available capacity, reflecting the proportion of the actual output torque of the roll damping device to its maximum available capacity under the current sea state and navigation conditions. The closer the ratio is to 1, the more likely the roll damping device is operating at full load, and the smaller the safety margin, the closer the ratio is to 0, indicating that there is a large surplus of roll damping capacity and a larger safety margin.

[0032] Simultaneously, the current real-time tension value is extracted based on the cable tension data, representing the actual tensile force borne by the cable at the current moment. The inherent parameters of the cable are obtained from the cable manufacturing specifications, including the cable's weight per unit length, breaking strength, and a set safety factor. The safety factor is preferably set between 2.0 and 3.0, determined according to industry standards such as DNV GL-ST-0351. The slant distance between the stern guide and the seabed landing point is measured in real-time using ranging sonar or an ultra-short baseline underwater acoustic positioning system. Combined with ship draft and water depth data, the length of the suspended section of the cable from the stern guide to the seabed landing point is obtained, i.e., the current suspended section length. Then, based on the cable's inherent parameters and the current suspended section length, the allowable tension upper limit is calculated. The allowable tension upper limit refers to the maximum safe tension the cable can withstand under the current suspended section length conditions. Allowable tension upper limit = min(cable breaking strength / safety factor, (cable weight per unit length × suspended section length)). 2 / 8d×catering shape correction coefficient), where d is the sag, i.e. the vertical drop from the guide cable to the landing point. The catering shape correction coefficient is preferably taken as 1.0~1.3. When the sag d is large, i.e. d / L > 0.15, the catering shape correction coefficient is taken as 1. When d / L < 0.04, a large correction is made, and the catering shape correction coefficient is taken as 1.3. When d / L = 0.08~0.15, the catering shape correction coefficient is taken as 1.05~1.10. When d / L = 0.04~0.08, the catering shape correction coefficient is taken as 1.10~1.20. That is, the smaller the sag, the larger the correction coefficient. Then, based on the upper limit of allowable tension and the current real-time tension value, the submarine cable tension safety margin index is calculated. The submarine cable tension safety margin index = current real-time tension value / upper limit of allowable tension value, which represents the proportion of the current real-time tension value to the upper limit of allowable tension value. The closer this ratio is to 1, the closer the submarine cable tension is to the safety boundary and the smaller the tension safety margin. The closer this ratio is to 0, the larger the tension safety margin.

[0033] For example, real-time data shows a ship with a roll angle of 5°, a pitch angle of 2°, a speed of 10 knots, a current output torque of 450 kN·m from the anti-roll tanks, a dominant wave frequency of 0.08 Hz, a significant wave height of 1.8 m, and a sea state of 4. After querying the capability database based on the operating conditions, under the current conditions of 10 knots, a roll angle of 5°, and sea state 4, the upper limit of the available capacity of the anti-roll device is 600 kN·m. Therefore, the ship's anti-roll safety margin index = 450 / 600 = 0.75, meaning the anti-roll device has used 75% of its capacity, with a remaining 25% margin. Meanwhile, based on the submarine cable manufacturing specifications, the cable's unit length weight is 3.0 kN / m, breaking strength is 120 kN, and safety factor is 2.5. The ranging sonar measured the stern guide cable distance from the landing point to be 2800 m. Combining the ship's draft of 8 m and water depth of 1200 m, the suspended section length L = 2200 m, the sag d = 1192 m, and d / L = 0.54 > 0.15. The catenary shape correction factor is taken as 1.0. Therefore, the allowable tension upper limit = min(120 / 2.5, (3.0 × 2200)² / (8 × 1192) × 1.0) = 48 kN. The submarine cable tension data shows that the current real-time tension value is 35 kN. Therefore, the submarine cable tension safety margin index = 35 / 48 ≈ 0.73, that is, the current tension accounts for 73% of the allowable upper limit, with a remaining tension margin of 27%.

[0034] By simultaneously quantifying the capability boundary of the anti-sway device and the tension boundary of the submarine cable, it is possible to determine, on a unified scale, whether the anti-sway capability is sufficient to support the current tension safety requirements of the submarine cable, thereby improving the accuracy and reliability of the dynamic adjustment of the length of the suspended section.

[0035] Furthermore, based on the operating status data of the roll reduction device, the current output torque of the roll reduction device is obtained. Combined with the ship motion status data and the current sea environment wave data, operating condition matching is performed to comprehensively determine the upper limit of the available capacity of the roll reduction device under the current operating condition. This includes: extracting the ship's current speed and attitude angle from the ship motion status data; extracting the current wave main frequency and sea state level from the current sea environment wave data; generating real-time operating condition information using the ship's current speed and attitude angle, the current wave main frequency, and the sea state level; and combining the current output torque and real-time operating condition information with a pre-built roll reduction device capacity database for matching to obtain the upper limit of the available capacity.

[0036] Specifically, the ship's current speed and attitude angles are extracted from the ship's motion state data. These attitude angles include at least the roll angle and pitch angle. The roll angle refers to the rotation angle around the ship's longitudinal central axis, reflecting the degree of lateral rolling. The pitch angle refers to the rotation angle around the ship's transverse axis, reflecting the degree of pitching. Simultaneously, the current dominant wave frequency and sea state level are extracted from the current marine environmental wave data. The dominant wave frequency refers to the frequency corresponding to the peak energy in the wave energy spectrum, reflecting the main periodic characteristics of the waves under the current sea state. This is specifically obtained by extracting the peak frequency after performing a fast Fourier transform spectral analysis on the sea surface echo signal using wave radar. Sea state ratings are based on significant wave heights, which are the average of the first third of the maximum wave heights recorded in a wave record, according to the internationally accepted Beaufort scale or the sea state classification system of the World Meteorological Organization. For example, a significant wave height of 0.1~0.5m corresponds to sea state level 2 (light wind), 0.5~1.25m corresponds to level 3 (slight waves), 1.25~2.5m corresponds to level 4 (moderate waves), 2.5~4.0m corresponds to level 5 (large waves), and so on up to level 9.

[0037] The system integrates the ship's current speed, attitude angle, current wave frequency, and sea state level to generate real-time operating condition information. Then, it uses the current output torque and real-time operating condition information as query criteria and inputs them into a pre-built anti-roll device capability database for matching. This database pre-stores the maximum available capacity upper limit of the anti-roll device under different operating condition combinations, calibrated based on extensive simulation calculations and actual ship tests. This upper limit represents the theoretically maximum stabilizing torque that the anti-roll device can output under specific sea state, speed, and attitude conditions. This maximum available capacity upper limit is affected by factors such as the anti-roll fin area and hydraulic pressure. Hardware constraints such as maximum system flow and control response bandwidth are used to precisely index the roll reduction device capability database using the current output torque and real-time operating condition information. When the matching parameters are completely matched, the upper limit of available capability corresponding to that operating condition is directly returned. When the matching parameters are not completely matched, nearest neighbor interpolation is used to take the nearest known operating condition within the range of speed ±1 knot, attitude angle ±2°, wave main frequency ±0.02Hz, and sea state level ±1 in the roll reduction device capability database. The upper limit of available capability is calculated through multidimensional linear interpolation, and then the upper limit of available capability under the current operating condition is obtained.

[0038] By matching real-time operating condition information, multi-source real-time data is mapped to the roll reduction device capability database, so that the determined upper limit of available capability truly reflects the capability boundary of the roll reduction device under the current environment. This avoids misjudgment of safety margin caused by using static rated values ​​instead of dynamic available values, ensuring the accuracy of ship roll reduction safety margin indicators, and thus improving the accuracy and reliability of ship roll reduction status assessment.

[0039] Calculate the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index. The matching degree index is used to characterize the degree of balance between the ship's current roll reduction capability and the submarine cable's current tension safety level.

[0040] Furthermore, calculating the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index includes: performing dimensionless processing on the ship roll reduction safety margin index and the submarine cable tension safety margin index, calculating the ratio between the dimensionless processed ship roll reduction safety margin index and the submarine cable tension safety margin index to obtain an initial matching degree index; and obtaining the matching degree index based on the degree of deviation between the initial matching degree index and the preset ideal matching range.

[0041] Furthermore, the matching degree index is obtained based on the degree of deviation between the initial matching degree index and the preset ideal matching range, including: the preset ideal matching range is the interval defined by the upper limit threshold and the lower limit threshold centered on the value 1; the degree of deviation and the direction of deviation between the initial matching degree index and the preset ideal matching range are calculated to generate the matching degree index.

[0042] Specifically, dimensionless processing of the ship roll reduction safety margin index and the submarine cable tension safety margin index means that the physical dimensions of the ship roll reduction safety margin index and the submarine cable tension safety margin index have been eliminated through ratio calculation in their respective calculation processes, so that they are uniformly converted into a value range of 0~1. Then, the dimensionless ship roll reduction safety margin index and the submarine cable tension safety margin index are compared to obtain the initial matching index. The initial matching index = ship roll reduction safety margin index / submarine cable tension safety margin index, which represents the multiple relationship between the ship roll reduction capacity margin and the submarine cable tension margin. When the initial matching index is equal to 1, it means that the ship roll reduction capacity margin and the submarine cable tension margin are perfectly matched and in an ideal equilibrium state. When the initial matching index is greater than 1, it means that the ship roll reduction capacity margin is greater than the submarine cable tension margin, that is, the roll reduction capacity is excessive while the submarine cable tension is tighter. When the initial matching index is less than 1, it means that the ship roll reduction capacity margin is less than the submarine cable tension margin, that is, the roll reduction capacity is tighter while the submarine cable tension is relatively excessive.

[0043] Then, the initial matching degree index is compared with the preset ideal matching range. The preset ideal matching range is the interval defined by the upper and lower thresholds centered on the value 1. The specific values ​​of the upper threshold αup and the lower threshold αlow are determined by combining the previous sea trial data and engineering experience. For example, αlow=0.85 and αup=1.15 can be set, that is, a deviation of ±15% is allowed. It can also be dynamically adjusted according to the severity of the sea conditions. The allowable deviation is narrowed in low sea conditions, such as 0.90~1.10, and the allowable deviation is widened in high sea conditions, such as 0.80~1.20, so as to reduce the adjustment frequency and reduce the wear of the actuator. By comparison, the deviation degree and direction of the initial matching degree index from the preset ideal matching range are calculated. If the initial matching degree index is within the ideal matching range, the initial matching degree index is directly taken, indicating that the current state is balanced. If the initial matching degree index is greater than the upper threshold, a positive deviation is marked, and the difference between the two is calculated and divided by the upper threshold to obtain the corresponding deviation degree, indicating that the ship's roll reduction capacity is in a surplus state. If the initial matching degree index is less than the lower threshold, the difference between the initial matching degree index and the lower threshold is calculated and divided by the lower threshold, and a negative deviation is marked, indicating that the submarine cable tension margin is excessive and the ship's roll reduction capacity is insufficient. Based on the deviation degree and direction, the matching degree index is generated. The matching degree index is a comprehensive evaluation index generated after quantitatively evaluating the relationship between the initial matching degree index and the preset ideal matching range. It includes the deviation degree and direction and is used to characterize the balance between the ship's current roll reduction capacity and the current tension safety level of the submarine cable. When the initial matching degree index is higher than the upper limit threshold, it corresponds to a state of surplus ship roll reduction capacity, indicating that the roll reduction device is under light load and the safety margin of the submarine cable tension is insufficient. When the initial matching degree index is lower than the lower limit threshold, it corresponds to a state of insufficient ship roll reduction capacity, indicating that the roll reduction device is close to full load and the submarine cable tension still has a large margin. When the initial matching degree index is between the upper and lower limits threshold, it indicates that the two safety margins are in an engineering-acceptable balanced operating state, and there is no need to perform suspension section length adjustment.

[0044] By using a matching index to collaboratively evaluate the ship roll reduction safety margin and the submarine cable tension safety margin, the traditional ship roll reduction control and submarine cable laying tension control are designed independently, providing operators with a clear decision-making basis. This enables dynamic optimal matching between ship roll reduction capability and submarine cable tension safety under complex sea conditions, achieving a balance between safety and efficiency, and improving the safety and adjustment accuracy of submarine cable laying operations.

[0045] Based on the matching degree index, the current anti-sway status is evaluated and an adjustment command for the length of the suspended segment is generated.

[0046] Furthermore, based on the matching degree index, the current roll reduction status is evaluated and an adjustment command for the length of the suspended section is generated, including: determining whether the ship's current roll reduction capability and the current tension safety level of the submarine cable are in a balanced state based on the matching degree index; if not, matching the suspended section length adjustment parameter in a preset balanced matching database based on the matching degree index and the deviation direction; and generating the suspended section length adjustment command based on the suspended section length adjustment parameter.

[0047] Furthermore, when generating the suspended section length adjustment command based on the suspended section length adjustment parameters, the adjustment is performed in stages according to the minimum adjustment step size, and after each adjustment, the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index is recalculated, and the adjustment monitoring is performed based on the recalculation results.

[0048] Specifically, based on the matching degree index, it is determined whether the ship's current roll reduction capability and the current tension safety level of the submarine cable are in a balanced state. When the deviation value in the matching degree index is 0, that is, the initial matching degree index falls within the preset ideal matching range, it indicates that the ship's current roll reduction capability and the current tension safety level of the submarine cable are in a balanced state. At this time, no adjustment command needs to be generated, the current suspended section length remains unchanged, and the monitoring continues in a cyclical manner with the current sampling period.

[0049] If the deviation value in the matching degree index is not 0, it is determined that the ship's current roll reduction capability and the current tension safety level of the submarine cable are not in equilibrium. At this time, according to the deviation degree and deviation direction in the matching degree index, the suspended section length adjustment parameter is matched in the preset equilibrium matching database. The equilibrium matching database pre-stores the suspended section length adjustment parameters corresponding to different deviation degrees and deviation directions. The suspended section length adjustment parameter refers to the target increment value ΔL (unit m) and adjustment step size δ (unit m) that need to be changed in the suspended section length under the current working conditions. Among them, a balanced matching database was constructed based on the nonlinear relationship between cable tension and suspended section length: shortening the suspended section length increases the sag d, thereby reducing the contribution of the parabolic term in the upper limit of allowable tension and reducing the actual tension, but at the same time, it increases the torque required by the anti-roll device; extending the suspended section length has the opposite effect. Through extensive simulation and real ship data calibration, a one-to-one mapping table of the target increment value ΔL of the suspended section length required to make the ship anti-roll safety margin index and the cable tension safety margin index simultaneously tend to the ideal matching range under different deviation degrees was obtained. This mapping table takes the deviation direction and deviation degree of the matching degree index as two dimensions, and in each deviation step... Under the combined conditions, by gradually adjusting the length of the suspended section and recording the response curves of the two safety margin indices after each adjustment, the change in the length of the suspended section that makes the matching degree index enter the ideal matching range for the first time is found as ΔL. At the same time, the maximum step size δ of a single adjustment is determined according to the sensitivity of the cable tension to the change in the length of the suspended section under the working condition. When the cable tension is sensitive to the change in length, such as when the sag is small and the catenary correction coefficient is large, δ is taken as a small value to avoid sudden tension changes. When the cable tension is not sensitive to the change in length, δ can be taken as a large value to speed up the adjustment convergence speed. All combinations of (ΔL,δ) under the working conditions are stored in the database for real-time query and retrieval, forming a balanced matching database.

[0050] Based on the suspended section length adjustment parameters, an empty section length adjustment command is generated. This command involves performing adjustments in stages according to the minimum adjustment step size. After each adjustment, data on ship motion, anti-roll device operation, cable tension, and environmental waves are re-collected. The ship anti-roll safety margin index and cable tension safety margin index are recalculated, and the initial matching degree index is recalculated. The newly calculated initial matching degree index is then compared again with the preset ideal matching range. The next action is determined based on the comparison result. If the recalculated initial matching degree index falls within the ideal matching range, the adjustment process is terminated early, indicating that the adjustment target has been achieved, and the system enters a balanced monitoring state. If the recalculated initial matching degree index is still not within the ideal matching range, but the deviation decreases, the next adjustment step is executed, following the original step size δ. If the recalculated deviation increases, a reverse fine-tuning correction operation is performed. Based on the current deviation degree and direction, the suspended section length adjustment parameters are re-matched in the preset balanced matching database until they fall within the ideal matching range, indicating that the adjustment target has been achieved.

[0051] For example, Figure 2 As shown, this is the process of balanced matching adjustment. The horizontal axis represents the adjustment steps, the left vertical axis represents the matching degree index, and the right vertical axis represents the length of the suspended section. Initially, the measured length of the suspended section is 180m, the initial matching degree index M=0.75, and the preset ideal matching range is [0.85, 1.15]. Then, the deviation degree Δ=(0.85-0.75) / 0.85≈0.118, the deviation direction is negative, and the anti-roll capability is insufficient. Based on the deviation degree and deviation direction, the target increment value ΔL=+18m is obtained from the balanced matching database, that is, the target suspended section length is 198m, and the adjustment step size δ=3m. A multi-stage adjustment command is generated, dividing the total increment of 18m into 6 steps, each... The length of the suspended section was increased by 3m after the first adjustment, becoming 183m. Data was re-collected and the new initial matching index M1=0.82 was calculated, which is less than the lower limit threshold of 0.85, but the deviation has decreased. Then, the second adjustment was performed according to the original step size. After the second adjustment, the length of the suspended section increased to 186m, and M2=0.87 was recalculated. At this time, the initial matching index fell within the ideal matching range [0.85, 1.15]. The subsequent four adjustments were immediately terminated, the adjustment target was determined to have been achieved, and the system was switched to the equilibrium monitoring state. The entire process only required two adjustments to complete the correction, which not only avoided over-adjustment but also verified the effectiveness of the adjustment effect through real-time feedback recalculation.

[0052] By mapping the abstract matching index to specific suspended section length adjustment parameters through a balanced matching database, and performing adjustments in stages with minimum step sizes, the matching index is recalculated after each adjustment for closed-loop monitoring. This avoids sudden increases in cable tension or abrupt unloading of the anti-sway device that could result from a large-scale adjustment at once, thus improving the safety and accuracy of cable deployment operations. Simultaneously, it ensures that the adjustment process for the suspended section length is smooth and controllable, ultimately achieving a true balance between anti-sway capability and the safe level of cable tension.

[0053] In summary, the ship roll reduction assessment method for submarine cable laying operations provided in this application has the following technical advantages: By collecting real-time data on ship motion status, anti-roll device operation status, submarine cable tension, and current marine wave conditions, the system calculates the ship anti-roll safety margin index and the submarine cable tension safety margin index in real time, and calculates the matching degree index between the two. This integrates the ship anti-roll capability and the submarine cable tension safety level into a unified quantitative evaluation framework. It achieves the quantification of the balance between the safety margins of the two parties through the matching degree index. Based on this matching degree index, the system assesses the current anti-roll status and generates a suspension section length adjustment command, executing dynamic and coordinated adjustment of the suspension section length. This ensures that the load of the anti-roll device and the submarine cable tension are always maintained within the engineering-acceptable matching range, thereby effectively avoiding operational risks caused by excessive consumption of safety margins by one party, and improving the overall safety and adjustment accuracy of submarine cable laying operations.

[0054] Example 2: Based on the same inventive concept as the ship roll reduction status assessment method for submarine cable laying operations in Example 1, this application also provides a ship roll reduction status assessment system for submarine cable laying operations. Please refer to the appendix. Figure 3 The ship roll reduction status assessment system for submarine cable laying operations includes: The data acquisition module 11 is used to collect real-time data on ship motion status, anti-roll device operation status, submarine cable tension, and current sea environment wave data, and to calculate the ship anti-roll safety margin index and the submarine cable tension safety margin index in real time. The matching degree calculation module 12 is used to calculate the matching degree index between the ship anti-roll safety margin index and the submarine cable tension safety margin index. The matching degree index is used to characterize the degree of balance between the ship's current anti-roll capability and the current tension safety level of the submarine cable. The status assessment module 13 is used to assess the current anti-roll status based on the matching degree index and generate a suspension section length adjustment command.

[0055] Furthermore, the status assessment module 13 is also used to: the length of the suspended section refers to the length of the suspended section of the submarine cable from the stern guide to the seabed landing point.

[0056] Furthermore, the data acquisition module 11 is also used to: obtain the current output torque of the anti-roll device based on the anti-roll device's operating status data; perform operating condition matching by combining the ship's motion status data and the current sea environment wave data; comprehensively determine the upper limit of the available capacity of the anti-roll device under the current operating condition; calculate the ship's anti-roll safety margin index based on the upper limit of available capacity and the current output torque; obtain the current real-time tension value based on the submarine cable tension data; determine the upper limit of allowable tension based on the inherent parameters of the submarine cable and the current suspended section length; and calculate the submarine cable tension safety margin index based on the upper limit of allowable tension and the current real-time tension value.

[0057] Furthermore, the data acquisition module 11 is also used to: extract the ship's current speed and attitude angle based on the ship's motion state data; extract the current wave main frequency and sea state level based on the current sea environment wave data; generate real-time operating condition information using the ship's current speed and attitude angle, the current wave main frequency and sea state level; and combine the current output torque and real-time operating condition information to call a pre-built anti-roll device capability database for matching to obtain the upper limit of the available capability.

[0058] Furthermore, the data acquisition module 11 is also used for: the ship roll reduction safety margin index characterizing the proportion of the current output torque to the maximum available capacity determined based on the current available capacity upper limit; and the submarine cable tension safety margin index characterizing the proportion of the current real-time tension value to the allowable tension upper limit.

[0059] Furthermore, the matching degree calculation module 12 is also used to: perform dimensionless processing on the ship roll reduction safety margin index and the submarine cable tension safety margin index, calculate the ratio between the ship roll reduction safety margin index and the submarine cable tension safety margin index after dimensionless processing, and obtain an initial matching degree index; and obtain the matching degree index based on the degree of deviation between the initial matching degree index and the preset ideal matching range.

[0060] Furthermore, the matching degree calculation module 12 is also used to: the preset ideal matching range is the interval defined by the upper limit threshold and the lower limit threshold centered on the value 1; calculate the degree of deviation and the direction of deviation between the initial matching degree index and the preset ideal matching range, and generate the matching degree index.

[0061] Furthermore, the state assessment module 13 is also used to: determine whether the ship's current roll reduction capability and the submarine cable's current tension safety level are in a balanced state based on the matching degree index; if not, match the suspended section length adjustment parameter in a preset balanced matching database based on the matching degree index and the deviation direction; and generate the suspended section length adjustment command based on the suspended section length adjustment parameter.

[0062] Furthermore, the state assessment module 13 is also used to: when generating the suspended section length adjustment command based on the suspended section length adjustment parameters, perform multi-stage adjustment according to the minimum adjustment step size, and recalculate the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index after each adjustment, and perform adjustment monitoring based on the recalculation results.

[0063] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0064] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of this application and its equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for assessing the roll reduction status of vessels used in submarine cable laying operations, characterized in that, include: Real-time data collection of ship motion status, anti-roll device operation status, submarine cable tension, and current marine environmental wave data; real-time calculation of ship anti-roll safety margin index and submarine cable tension safety margin index. Calculate the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index. The matching degree index is used to characterize the degree of balance between the ship's current roll reduction capability and the submarine cable's current tension safety level. Based on the matching degree index, the current anti-sway status is evaluated and an adjustment command for the length of the suspended segment is generated.

2. The method for assessing the roll reduction status of a vessel used in submarine cable laying operations as described in claim 1, characterized in that, The length of the suspended section refers to the length of the submarine cable suspended from the stern guide to the seabed landing point.

3. The method for assessing the roll reduction status of a vessel used in submarine cable laying operations as described in claim 1, characterized in that, Real-time data collection of ship motion status, anti-roll device operation status, submarine cable tension, and current marine environmental wave data; real-time calculation of ship anti-roll safety margin and submarine cable tension safety margin, including: The current output torque of the anti-roll device is obtained based on the operating status data of the anti-roll device. The working condition is matched by combining the ship motion status data and the current sea environment wave data to comprehensively determine the upper limit of the available capacity of the anti-roll device under the current working condition. The ship roll reduction safety margin index is calculated based on the available capacity upper limit and the current output torque; The current real-time tension value is obtained based on the submarine cable tension data, and the upper limit of allowable tension is determined based on the inherent parameters of the submarine cable and the current length of the suspended section. The cable tension safety margin index is calculated based on the allowable tension upper limit and the current real-time tension value.

4. The method for assessing the roll reduction status of a vessel used in submarine cable laying operations as described in claim 3, characterized in that, The current output torque of the roll damping device is obtained based on the operating status data of the roll damping device. Combined with the ship motion status data and the current sea environment wave data, operating condition matching is performed to comprehensively determine the upper limit of the available capacity of the roll damping device under the current operating condition, including: The ship's current speed and attitude angle are extracted based on the ship's motion state data. Extract the current wave frequency and sea state level based on the current marine environment wave data; Real-time operational information is generated based on the ship's current speed and attitude angle, current wave frequency, and sea state level. By combining the current output torque and real-time operating condition information, a pre-built database of anti-sway device capabilities is invoked for matching to obtain the upper limit of the available capabilities.

5. The method for assessing the roll reduction status of a vessel used in submarine cable laying operations as described in claim 3, characterized in that, The ship roll reduction safety margin index represents the proportion of the current output torque to the maximum available capacity determined based on the current upper limit of available capacity. The submarine cable tension safety margin index represents the proportion of the current real-time tension value to the upper limit of the allowable tension value.

6. The method for assessing the roll reduction status of a vessel used in submarine cable laying operations as described in claim 1, characterized in that, Calculating the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index includes: The ship roll reduction safety margin index and the submarine cable tension safety margin index are dimensionless, and the ratio between the dimensionless ship roll reduction safety margin index and the submarine cable tension safety margin index is calculated to obtain the initial matching degree index. The matching degree index is obtained based on the degree of deviation between the initial matching degree index and the preset ideal matching range.

7. The method for assessing the roll reduction status of a vessel used in submarine cable laying operations as described in claim 6, characterized in that, The matching degree index is obtained based on the degree of deviation between the initial matching degree index and the preset ideal matching range, including: The preset ideal matching range is the interval defined by the upper and lower thresholds centered on the value 1; The degree and direction of deviation between the initial matching index and the preset ideal matching range are calculated to generate the matching index.

8. The method for assessing the roll reduction status of a vessel used in submarine cable laying operations as described in claim 1, characterized in that, Based on the matching degree index, the current anti-roll status is evaluated and a suspension segment length adjustment command is generated, including: Based on the matching index, determine whether the ship's current roll reduction capability and the submarine cable's current tension safety level are in equilibrium. If not, based on the matching degree index and the deviation direction, match the suspended segment length adjustment parameter in the preset balanced matching database; The empty segment length adjustment command is generated based on the suspended segment length adjustment parameters.

9. The method for assessing the roll reduction status of a vessel used in submarine cable laying operations as described in claim 8, characterized in that, When generating the suspended section length adjustment command based on the suspended section length adjustment parameters, the adjustment is performed in stages according to the minimum adjustment step size. After each adjustment, the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index is recalculated, and the adjustment monitoring is performed based on the recalculation results.

10. A ship roll reduction status assessment system for submarine cable laying operations, characterized in that, The method for assessing the roll reduction status of a vessel for submarine cable laying operations as described in any one of claims 1 to 9, wherein the system for assessing the roll reduction status of a vessel for submarine cable laying operations comprises: The data acquisition module is used to collect real-time data on ship motion status, anti-roll device operation status, submarine cable tension, and current marine environmental wave data, and to calculate the ship anti-roll safety margin index and submarine cable tension safety margin index in real time. The matching degree calculation module is used to calculate the matching degree index between the ship roll reduction safety margin index and the submarine cable tension safety margin index. The matching degree index is used to characterize the degree of balance between the ship's current roll reduction capability and the submarine cable's current tension safety level. The status assessment module is used to assess the current sway reduction status based on the matching degree index and generate an instruction to adjust the length of the suspended section.

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