A method and system for risk early warning of a suspended submarine cable based on a real-time motion state

Abstract

The present application relates to the technical field of offshore wind power cable monitoring, and discloses a method and system for risk early warning of suspended sea cable based on real-time motion state. The method comprises: arranging a sensor array on a target sea cable suspended section to collect motion data in real time; constructing a rotation matrix based on an attitude angle, filtering out the gravity component in acceleration through coordinate transformation to obtain pure motion acceleration; integrating the motion acceleration in time domain to calculate displacement, and simultaneously fusing angular velocity and attitude angle to reconstruct the three-dimensional spatial form of the sea cable, and extract the swing amplitude and bending degree; comparing the swing amplitude and the safety threshold, and the bending degree and the safety threshold in real time, generating an early warning signal according to the early warning rules based on the comparison result; triggering an audible and light alarm based on the early warning signal and generating an operation and maintenance instruction. The complete monitoring link from data collection to active intervention is realized, the reliability of monitoring is greatly improved, a double-threshold early warning mechanism is established, a closed-loop control is formed, and a high-reliability and low-cost suspended sea cable risk prevention and control system is constructed.

Description

Technical Field

[0001] This invention relates to the field of submarine cable monitoring and early warning technology, and in particular to a method and system for early warning of risks of suspended submarine cables based on real-time motion status. Background Technology

[0002] Offshore wind power, as a crucial component of clean energy, relies heavily on the safe and stable operation of its submarine cables, which directly impact the reliability of the entire wind farm system. When connecting offshore wind turbines, substations, and onshore control centers, submarine cables are susceptible to scour near the pile foundations due to seabed topography and hydrodynamic conditions, leading to increased lengths of suspended cable sections. Under the influence of periodic ocean currents, these suspended cables oscillate back and forth, causing fatigue damage to the lead sheath and exceeding tension limits, ultimately resulting in cable breakage. Therefore, real-time monitoring of the movement of suspended submarine cables is essential for preventing malfunctions.

[0003] However, current mainstream monitoring technologies have significant limitations: towed side-scan sonar systems rely on manual signal interpretation, cannot achieve real-time monitoring, and their positioning accuracy is affected by hydrological conditions; underwater robots carrying optical equipment operate slowly and are costly, and fail in turbid waters; while magnetometer detection can identify cable locations, it requires the probe to be close to the seabed and is not suitable for deeply buried cables. These methods are ill-suited to complex marine environments, lack long-term in-situ monitoring capabilities, resulting in high maintenance costs and delayed accident warnings. Therefore, there is an urgent need to develop a low-cost, highly reliable risk warning method capable of capturing the three-dimensional motion of submarine cables in real time to overcome the technical bottlenecks in dynamic monitoring of suspended sections. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for risk warning of suspended submarine cables based on real-time motion status, comprising the following steps:

[0005] S1. Deploy a sensor array in the suspended section of the target submarine cable and use the sensor array to collect motion data of the target submarine cable. The motion data includes attitude angle data, triaxial acceleration and triaxial angular velocity.

[0006] S2. Based on attitude angle data, the gravitational acceleration component is filtered out from the triaxial acceleration through coordinate transformation to obtain the motion acceleration of the target submarine cable;

[0007] S3. Perform time-domain integration on the motion acceleration to calculate the displacement of the target submarine cable; combine the three-axis angular velocity and attitude angle data to reconstruct the three-dimensional spatial shape of the target submarine cable and extract its swing amplitude and curvature.

[0008] S4. Real-time comparison of swing amplitude with swing amplitude threshold and curvature with curvature threshold, and generate early warning signals according to early warning rules based on the comparison results;

[0009] S5. Trigger alarms based on early warning signals and generate operation and maintenance instructions.

[0010] Furthermore, in S1, the sensor array is deployed in the suspended section of the target submarine cable, including: setting sensors at intervals along the axial direction of the target submarine cable; when the length of the suspended section is less than or equal to a preset length, the spacing between adjacent sensors is set to a preset interval; when the length of the suspended section is greater than the preset length, the spacing between adjacent sensors is a preset proportion of the preset length.

[0011] Furthermore, in S2, based on attitude angle data, the gravitational acceleration component is filtered out from the triaxial acceleration through coordinate transformation to obtain the motion acceleration of the target submarine cable, including:

[0012] S21. Construct a rotation matrix based on attitude angle data;

[0013] S22. Transform the triaxial acceleration from the sensor coordinate system to the geodetic coordinate system based on the rotation matrix;

[0014] S23. Subtract the gravity vector from the triaxial acceleration in the geodetic coordinate system to obtain the acceleration due to motion.

[0015] Furthermore, in S3, the motion acceleration is integrated in the time domain to calculate the displacement of the target submarine cable, including:

[0016] S31. The continuous time interval [t0, t...] w The time series is discretized into w equally divided time intervals, corresponding to time series t0, t1, ..., t2. W ;

[0017] S32. For each time point t k acceleration a k Perform a single integral to calculate the instantaneous velocity v. k The calculation formula is:

[0018] ;

[0019] in, v k Let v be the instantaneous velocity at the k-th moment. k-1 Let a be the instantaneous velocity at time k-1. k Let Δt be the acceleration between time k-1 and time k, and Δt be the time interval between two adjacent time points.

[0020] S33, Instantaneous velocity v at adjacent time points k-1 and v k By performing a double integral and accumulating the displacement s of the target submarine cable through a trapezoidal surface, the calculation formula is as follows:

[0021] ;

[0022] Where s0 is the initial displacement.

[0023] Furthermore, in S3, by combining triaxial angular velocity and attitude angle data, the three-dimensional spatial morphology of the target submarine cable is reconstructed, and its swing amplitude and curvature are extracted, including:

[0024] S3b1. Using the sensor positions as nodes and the submarine cable segments between adjacent nodes as rigid links, construct the orientation rotation matrix in the local coordinate system based on the attitude angle data output by each sensor.

[0025] S3b2. Using the first node as the reference point, set the contact point P0 between the target submarine cable and the seabed. Based on the spacing and orientation rotation matrix of adjacent nodes, sequentially calculate the positions of subsequent nodes to obtain the coordinate sequence {P0, P1, ..., P...} of the target submarine cable. n}, where n is the number of nodes;

[0026] S3b3. Based on the coordinate sequence, calculate the maximum instantaneous offset to obtain the swing amplitude;

[0027] S3b4. Based on the coordinate sequence, generate the front vector and back vector of each node, and calculate the local bending angle of the current node based on the front vector and back vector, that is, obtain the bending degree of the target submarine cable; the front vector is the vector between the current node and the previous node, and the back vector is the vector between the current node and the next node.

[0028] Furthermore, in S4, the swing amplitude is compared with the swing amplitude threshold and the curvature with the curvature threshold in real time. Based on the comparison results, an early warning signal is generated according to the early warning rules, including: setting the swing amplitude threshold and the curvature threshold; generating a first-level early warning signal when the swing amplitude exceeds the swing amplitude threshold or the curvature exceeds the curvature threshold; and generating a second-level emergency early warning signal when both the swing amplitude and the curvature exceed their respective thresholds.

[0029] Furthermore, in S5, alarms are triggered and maintenance instructions are generated based on early warning signals, including: when a Level 1 early warning signal is received, a normal audible and visual alarm is triggered, and maintenance instructions are generated; the maintenance instructions include: increasing the sampling frequency of the sensor array, starting seabed topography scanning, and sending the risk location coordinates and real-time oscillation data to the maintenance terminal, the oscillation data including displacement, oscillation amplitude, and curvature; when a Level 2 emergency early warning signal is received, a high-frequency pulse audible and visual alarm is triggered, and emergency maintenance instructions are generated; the emergency maintenance instructions include: controlling the generator set to operate at reduced power to a safe threshold, starting the underwater inspection pre-deployment procedure, and sending the maintenance coordinates and optimal navigation path to the nearest maintenance vessel.

[0030] This invention also provides a suspended submarine cable risk early warning system based on real-time motion status, used to execute the above-mentioned suspended submarine cable risk early warning method based on real-time motion status. The system includes the following modules:

[0031] The data acquisition module is used to deploy a sensor array on the suspended section of the target submarine cable and use the sensor array to collect motion data of the target submarine cable, including attitude angle data, triaxial acceleration and triaxial angular velocity.

[0032] Data processing module: Connected to the data acquisition module, it is used to filter out the gravitational acceleration component from the three-axis acceleration based on attitude angle data through coordinate transformation, and obtain the motion acceleration of the target submarine cable;

[0033] Motion Analysis Module: Connected to the data processing module, it is used to perform time-domain integration of motion acceleration to calculate the displacement of the target submarine cable; combined with triaxial angular velocity and attitude angle data, it reconstructs the three-dimensional spatial morphology of the target submarine cable and extracts its swing amplitude and curvature.

[0034] Risk warning module: Connected to the motion analysis module, it is used to compare the swing amplitude with the safe swing amplitude threshold and the curvature with the safe curvature threshold in real time, and generate warning signals according to the warning rules based on the comparison results;

[0035] Response Execution Module: Connected to the risk warning block, it is used to trigger alarms and generate operation and maintenance instructions based on warning signals.

[0036] The embodiments of the present invention have the following technical effects:

[0037] This invention utilizes a sensor array to collect real-time data on the attitude angle, acceleration, and angular velocity of submarine cables. Based on the attitude angle data, a rotation matrix is ​​constructed for coordinate transformation, effectively filtering out the interference of gravity components on motion acceleration and solving the data distortion problem caused by environmental noise in traditional sonar / optical monitoring. By accurately calculating the displacement of the submarine cable through time-domain integration of motion acceleration, it achieves monitoring of fatigue under alternating loads. Furthermore, by combining angular velocity and attitude angle data, the three-dimensional spatial morphology of the submarine cable is reconstructed, and the swing amplitude and curvature parameters of the suspended section are extracted to monitor local bending stress, overcoming the limitation of magnetometers in simultaneously quantifying dynamic motion and static deformation. By setting swing and bending safety thresholds and establishing graded early warning rules, different levels of warnings are triggered when the displacement increases abnormally or the curvature becomes excessive, realizing a complete monitoring link from data acquisition to active intervention. This significantly improves monitoring reliability and effectively shortens response delay compared to sonar monitoring. The sensor hardware reduces maintenance costs compared to underwater robots, ultimately forming a low-cost, highly reliable risk early warning method capable of capturing the three-dimensional motion state of submarine cables in real time. Attached Figure Description

[0038] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0039] Figure 1 This is a flowchart of the method for risk warning of suspended submarine cables based on real-time motion status provided in an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of the movement of the target submarine cable provided in an embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the structure of the suspended submarine cable risk early warning system based on real-time motion status provided in an embodiment of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0043] This invention proposes a risk warning method for suspended submarine cables based on real-time motion status. Figure 1 This is a flowchart of the method for risk warning of suspended submarine cables based on real-time motion status provided in an embodiment of the present invention. See also... Figure 1 Specifically, it includes:

[0044] S1. Deploy a sensor array in the suspended section of the target submarine cable and use the sensor array to collect motion data of the target submarine cable. The motion data includes attitude angle data, triaxial acceleration and triaxial angular velocity.

[0045] Specifically, a sensor array is deployed in the suspended section of the target submarine cable, including: setting sensors at intervals along the axial direction of the target submarine cable; when the length of the suspended section is less than or equal to a preset length, the spacing between adjacent sensors is set to a preset interval; when the length of the suspended section is greater than the preset length, the spacing between adjacent sensors is a preset proportion of the preset length.

[0046] In some embodiments, for a monitoring project of a suspended section of a submarine cable in an offshore wind farm, a 35-meter suspended section caused by scour pits was first confirmed using a multibeam echo sounder to show that the length of the suspended section exceeded a preset threshold of 20 meters. According to dynamic deployment rules, the sensor spacing was calculated to be 3.5 meters, based on 10% of the suspended section length. Using the contact point between the cable and the stable seabed as the reference position, marked a0, the first waterproof encapsulated MEMS-IMU sensor was installed, with its stainless steel clamp fixing point 5 centimeters from the cable surface. Sensor nodes were then deployed sequentially along the cable axis downstream, every 3.5 meters, until the end of the suspended section, for a total of 10 sensors. Specifically, in the edge area of ​​the scour pit, identified as a high-curvature risk area at the end of a J-shaped pipe, two additional sensors were added, compressing the local spacing to 1.5 meters to improve deformation monitoring resolution. All sensors were connected in series to the control center via armored optical cables, and underwater pressure sealing was performed using heat-shrink tubing during installation. Compared to the traditional equidistant deployment scheme, this embodiment achieves full coverage with only 12 sensors, reducing installation costs and improving the correlation coefficient of acceleration signals from adjacent sensors. This effectively captures curvature abrupt changes at the edge of scour pits, enhancing the specific monitoring capability for scour risk at the end of the J-shaped pipe. The deployed sensor array collects real-time attitude angle data, triaxial acceleration, and triaxial angular velocity of the target submarine cable.

[0047] S2. Based on attitude angle data, the gravitational acceleration component is filtered out from the three-axis acceleration through coordinate transformation to obtain the motion acceleration of the target submarine cable. Specifically, this includes:

[0048] S21. Construct a rotation matrix based on attitude angle data;

[0049] S22. Transform the triaxial acceleration from the sensor coordinate system to the geodetic coordinate system based on the rotation matrix;

[0050] S23. Subtract the gravity vector from the triaxial acceleration in the geodetic coordinate system to obtain the acceleration due to motion.

[0051] In some embodiments, such as Figure 2 As shown, the MEMS-IMU sensor installed on the suspended section collects motion data of the target submarine cable. Its output attitude angle data includes pitch angle θ, roll angle γ, and yaw angle ψ, which serve as the basis for constructing the rotation matrix. First, the rotation matrix R is constructed using ZYX Euler angle transformation:

[0052] ;

[0053] Where R is the rotation matrix, describing the composite rotation transformation in three-dimensional space; Rx(γ) is the rotation matrix for rotating about the x-axis by an angle γ; Ry(θ) is the rotation matrix for rotating about the y-axis by an angle θ; and Rz(ψ) is the rotation matrix for rotating about the z-axis by an angle ψ.

[0054] Then, a coordinate system transformation is performed using the rotation matrix R, converting the sensor coordinate system to the geodetic coordinate system. The original acceleration a measured by the sensor is then obtained. s That is, the acceleration in the sensor coordinate system is transformed to the geodetic coordinate system through the rotation matrix R. The transformation formula is as follows:

[0055] ;

[0056] in, The acceleration in the sensor coordinate system (including motion acceleration + gravity component). This is the acceleration in the geodetic coordinate system (still including the gravitational component).

[0057] Finally, the gravitational component is filtered out, thus separating the acceleration due to motion. In the geodetic coordinate system, the gravity vector is assumed to be g=[0,0,1g]. T (The z-axis of the geodetic coordinate system points to the Earth's center), after subtracting gravity, we obtain the pure acceleration due to motion:

[0058] ;

[0059] in, It is the acceleration of motion.

[0060] S3. Perform time-domain integration on the motion acceleration to calculate the displacement of the target submarine cable; combine the triaxial angular velocity and attitude angle data to reconstruct the three-dimensional spatial shape of the target submarine cable and extract its swing amplitude and curvature.

[0061] Specifically, in S3, the motion acceleration is integrated in the time domain to calculate the displacement of the target submarine cable, including:

[0062] S31. The continuous time interval [t0, t...] w The time series is discretized into w equally divided time intervals, corresponding to time series t0, t1, ..., t2. W ;

[0063] S32. For each time point t k acceleration a k Perform a single integral to calculate the instantaneous velocity v. k The calculation formula is:

[0064] ;

[0065] in, v k Let v be the instantaneous velocity at the k-th moment. k-1 Let a be the instantaneous velocity at time k-1. k Let Δt be the acceleration between time k-1 and time k, and Δt be the time interval between two adjacent time points.

[0066] S33, Instantaneous velocity v at adjacent time points k-1 and v k By performing a double integral and accumulating the displacement s of the target submarine cable through a trapezoidal surface, the calculation formula is as follows:

[0067] ;

[0068] Where s0 is the initial displacement.

[0069] In some embodiments, the displacement of the target submarine cable during a 12-second strong current window during the passage of a typhoon is calculated, where t0 = 0s, t w =12s.

[0070] First, time discretization is performed, dividing the 12-second interval into 1200 equal time slots, i.e., w=1200, with a time interval Δt=0.01s, generating a time series t0=0, t1=0.01,...,t 1200 =12s.

[0071] Then, extract each t k The acceleration a at time t is k , where a k Gravity has been filtered out through step S2, such as t 600 =6s a 600 =1.83g; Calculate the instantaneous velocity integral, with the initial velocity v0 being the measured flow velocity at the bottom of the scour pit, which is 0.32m / s;

[0072] From the formula The instantaneous velocity at all times is calculated recursively. An example segment is shown below, showing the velocity at time 601:

[0073]

[0074] Speed ​​at time 602:

[0075]

[0076] Finally, the total displacement within this time window is obtained by trapezoidal integration of the displacement, denoted as t. 600 ~t 602 Taking time period as an example, v 600 =1.47m / s,v 601 =1.64m / s,v 602 =1.84m / s from the formula Calculation yields:

[0077]

[0078] Initial displacement: s0=0m, the total displacement over the entire time period is s=2.17m.

[0079] Specifically, in S3, by combining triaxial angular velocity and attitude angle data, the three-dimensional spatial morphology of the target submarine cable is reconstructed, and its swing amplitude and curvature are extracted, including:

[0080] S3b1. Using the sensor positions as nodes and the submarine cable segments between adjacent nodes as rigid links, construct the orientation rotation matrix in the local coordinate system based on the attitude angle data output by each sensor.

[0081] S3b2. Using the first node as the reference point, set the contact point P0 between the target submarine cable and the seabed. Based on the spacing and orientation rotation matrix of adjacent nodes, sequentially calculate the positions of subsequent nodes to obtain the coordinate sequence {P0, P1, ..., P...} of the target submarine cable. n}, where n is the number of nodes;

[0082] S3b3. Based on the coordinate sequence, calculate the maximum instantaneous offset to obtain the swing amplitude;

[0083] S3b4. Based on the coordinate sequence, generate the front vector and back vector of each node, and calculate the local bending angle of the current node based on the front vector and back vector, that is, obtain the bending degree of the target submarine cable; the front vector is the vector between the current node and the previous node, and the back vector is the vector between the current node and the next node.

[0084] In some embodiments, the three-dimensional spatial morphology of the target submarine cable is reconstructed by combining triaxial angular velocity and attitude angle data, and its swing amplitude and curvature are extracted. Based on the attitude angle data output by each sensor, a direction rotation matrix in the local coordinate system is constructed, as shown in the formula: , where R k Let be the rotation matrix for the k-th sensor; Rotation about the x, y, and z axes respectively , , The basic rotation matrix is ​​multiplied in the order of right to left, i.e., roll first, then pitch, and finally yaw.

[0085] Its reference position is the seabed contact point P0, with coordinates [0,0,0]. Taking the sensor at position P1 as an example, its output attitude angle data are as follows: pitch angle θ1 = -8.2°, roll angle γ1 = 3.5°, yaw angle ψ1 = 172.3°. Then the rotation matrix result is:

[0086] ;

[0087] The coordinates of each node are obtained by summing the coordinates of the previous node and the rotated sensor spacing vector, as shown in the formula:

[0088] ;

[0089] Among them, P k Let P be the coordinates of the k-th node. k-1 Let R be the coordinates of the node preceding the k-th node. k-1 Let be the rotation matrix of the (k-1)th sensor. The spacing vector of the sensors (along the z-axis of the sensor coordinate system, d) k (where P0 is the spacing of the kth segment), and the reference matrix R0 = I (identity matrix, P0 is the reference point, with no rotation).

[0090] The sensor spacing is 3.5 meters, i.e., d2 = 3.5m. Therefore, point P2 can be calculated.

[0091] ;

[0092] Expand and calculate the rotated vector: ;

[0093] Ultimately, it can be obtained ;

[0094] By analogy, the coordinate sequence {P0, P1, ..., P} of the target submarine cable can be calculated. n}

[0095] Based on the above coordinate sequence, the swing amplitude is the Euclidean distance between the peak position of the target submarine cable's movement and its initial position, as shown in the following formula:

[0096] ;

[0097] Among them, A swing P represents the amplitude of the swing. k0 Let P be the initial node position. kt This represents the node position at the peak of the motion. Let be the Euclidean distance between the two positions of node k. Calculate the swing amplitude of each node, and select the largest swing amplitude as the swing amplitude of the target submarine cable at the current moment.

[0098] The bending angle at each node is the angle between the two segments of the submarine cable before and after that node, calculated using the vector dot product formula:

[0099] ;

[0100] Where, β k Let the bending angle be the angle of the k-th node. Let k be the vector between node k and the previous node. Let k be the vector between node k and the next node. Calculate the bending angle of each node, and select the largest bending angle as the bending angle of the target submarine cable at the current moment.

[0101] S4. Real-time comparison of swing amplitude with swing amplitude threshold and curvature with curvature threshold, and generate early warning signals according to early warning rules based on the comparison results.

[0102] Specifically, swing amplitude threshold and curvature threshold are set; when the swing amplitude exceeds the swing amplitude threshold or the curvature exceeds the curvature threshold, a first-level warning signal is generated; when both the swing amplitude and curvature exceed their respective thresholds, a second-level emergency warning signal is generated.

[0103] In some embodiments, the swing amplitude threshold is set to 0.8 meters, and the curvature threshold is set to 15 degrees. The target submarine cable's swing amplitude (Aswing) is detected to be 1.32 meters, exceeding the swing amplitude threshold, while the curvature is 11.2 degrees, not exceeding the curvature threshold. At this point, a level one warning signal is triggered, automatically increasing the sensor sampling rate from 100Hz to 200Hz; the audible and visual alarm command in the control center is activated, pushing alarm information to the maintenance terminal. The alarm location coordinates are: E113°34'22", N21°12'18"; the swing amplitude is 1.32 meters.

[0104] In some embodiments, the swing amplitude A of the target submarine cable is monitored. swing =1.05m, exceeding the swing amplitude threshold, and the curvature is 16.8 degrees, exceeding the curvature threshold. At this time, a level two emergency warning signal is triggered, the audible and visual alarm is upgraded to red pulse mode, the wind turbine load reduction command is automatically executed, the pre-deployed underwater inspection program is activated, the fault point imaging task is loaded to confirm the reliability of the alarm information, and the nearest maintenance vessel is dispatched for repair. Specific information includes: coordinates: [113.5736, 21.2082], path: AIS route #7, time taken: 85 minutes.

[0105] S5. Trigger alarms based on early warning signals and generate operation and maintenance instructions.

[0106] Specifically, upon receiving a Level 1 warning signal, a standard audible and visual alarm is triggered, and maintenance instructions are generated. These instructions include: increasing the sensor array sampling frequency, initiating seabed topography scanning, and sending the risk location coordinates and real-time oscillation data to the maintenance terminal. The oscillation data includes displacement, oscillation amplitude, and curvature. Upon receiving a Level 2 emergency warning signal, a high-frequency pulse audible and visual alarm is triggered, and emergency maintenance instructions are generated. These instructions include: controlling the generator set to operate at reduced power to a safe threshold, initiating an underwater inspection pre-deployment procedure, and sending the maintenance coordinates and optimal navigation path to the nearest maintenance vessel.

[0107] Figure 3This is a schematic diagram of a suspended submarine cable risk warning system based on real-time motion state provided in an embodiment of the present invention. This system is used to execute a suspended submarine cable risk warning method based on real-time motion state as described in the above embodiment, such as... Figure 3 As shown, the system includes the following modules:

[0108] The data acquisition module is used to deploy a sensor array on the suspended section of the target submarine cable and use the sensor array to collect motion data of the target submarine cable, including attitude angle data, triaxial acceleration and triaxial angular velocity.

[0109] Data processing module: Connected to the data acquisition module, it is used to filter out the gravitational acceleration component from the three-axis acceleration based on attitude angle data through coordinate transformation, and obtain the motion acceleration of the target submarine cable;

[0110] Motion Analysis Module: Connected to the data processing module, it is used to perform time-domain integration of motion acceleration to calculate the displacement of the target submarine cable; combined with triaxial angular velocity and attitude angle data, it reconstructs the three-dimensional spatial morphology of the target submarine cable and extracts its swing amplitude and curvature.

[0111] Risk warning module: Connected to the motion analysis module, it is used to compare the swing amplitude with the safe swing amplitude threshold and the curvature with the safe curvature threshold in real time, and generate warning signals according to the warning rules based on the comparison results;

[0112] Response Execution Module: Connected to the risk warning block, it is used to trigger alarms and generate operation and maintenance instructions based on warning signals.

[0113] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for risk early warning of suspended submarine cables based on real-time motion status, characterized in that, Includes the following steps: S1. Deploy a sensor array in the suspended section of the target submarine cable and use the sensor array to collect motion data of the target submarine cable. The motion data includes attitude angle data, triaxial acceleration and triaxial angular velocity. S2. Based on the attitude angle data, the gravitational acceleration component is filtered out from the triaxial acceleration by coordinate transformation to obtain the motion acceleration of the target submarine cable; S3. Perform time-domain integration on the motion acceleration to calculate the displacement of the target submarine cable; combine the triaxial angular velocity and attitude angle data to reconstruct the three-dimensional spatial shape of the target submarine cable, and extract its swing amplitude and curvature. S4. Real-time comparison of the swing amplitude with the swing amplitude threshold and the curvature with the curvature threshold, and generate an early warning signal based on the comparison results and according to the early warning rules; S5. Trigger an alarm based on the warning signal and generate maintenance instructions; In step S3, the three-dimensional spatial morphology of the target submarine cable is reconstructed by combining the three-axis angular velocity and attitude angle data, and its swing amplitude and curvature are extracted, including: S3b1. Using the sensor positions as nodes and the submarine cable segments between adjacent nodes as rigid links, construct the orientation rotation matrix in the local coordinate system based on the attitude angle data output by each sensor. S3b2. Taking the first node as the reference point, set the contact point P0 between the target submarine cable and the seabed. Based on the spacing between adjacent nodes and the direction rotation matrix, calculate the positions of subsequent nodes in sequence to obtain the coordinate sequence {P0, P1, ..., Pn} of the target submarine cable, where n is the number of nodes. S3b3. Based on the coordinate sequence, calculate the maximum instantaneous offset to obtain the swing amplitude; S3b4. Based on the coordinate sequence, generate a front vector and a back vector for each node, and calculate the local bending angle of the current node based on the front vector and the back vector, thereby obtaining the bending degree of the target submarine cable; the front vector is the vector between the current node and the previous node, and the back vector is the vector between the current node and the next node.

2. The method for risk early warning of suspended submarine cables based on real-time motion status according to claim 1, characterized in that, In step S1, a sensor array is deployed in the suspended section of the target submarine cable, including: Sensors are spaced apart along the axial direction of the target submarine cable. When the length of the suspended section is less than or equal to a preset length, the spacing between adjacent sensors is set to a preset interval. When the length of the suspended section is greater than the preset length, the spacing between adjacent sensors is a preset proportion of the preset length.

3. The method for risk early warning of suspended submarine cables based on real-time motion status according to claim 2, characterized in that, In step S2, based on the attitude angle data, the gravitational acceleration component is filtered out from the triaxial acceleration through coordinate transformation to obtain the motion acceleration of the target submarine cable, including: S21. Construct a rotation matrix based on the attitude angle data; S22. Based on the rotation matrix, transform the triaxial acceleration from the sensor coordinate system to the geodetic coordinate system; S23. Subtract the gravity vector from the triaxial acceleration in the geodetic coordinate system to obtain the motion acceleration.

4. The method for risk early warning of suspended submarine cables based on real-time motion status according to claim 1, characterized in that, In step S3, the motion acceleration is integrated in the time domain to calculate the displacement of the target submarine cable, including: S31. The continuous time interval [t0, t...] w The time series is discretized into w equally divided time intervals, corresponding to time series t0, t1, ..., t2. W ; S32. For each time point t k acceleration a k Perform a single integral to calculate the instantaneous velocity v. k The calculation formula is: ； in, v k Let v be the instantaneous velocity at the k-th moment. k-1 Let a be the instantaneous velocity at time k-1. k Let Δt be the acceleration between time k-1 and time k, and Δt be the time interval between two adjacent time points. S33, Instantaneous velocity v at adjacent time points k-1 and v k By performing a double integral and accumulating the displacement s of the target submarine cable through the trapezoidal surface, the calculation formula is as follows: ； Where s0 is the initial displacement.

5. The method for risk early warning of suspended submarine cables based on real-time motion status according to claim 1, characterized in that, In step S4, the swing amplitude is compared with the swing amplitude threshold and the curvature with the curvature threshold in real time. Based on the comparison results, an early warning signal is generated according to the early warning rules, including: Set the swing amplitude threshold and the curvature threshold; When the swing amplitude exceeds the swing amplitude threshold, or the curvature exceeds the curvature threshold, a first-level warning signal is generated; When the swing amplitude and bending degree both exceed their respective thresholds, a level two emergency warning signal is generated.

6. The method for risk early warning of suspended submarine cables based on real-time motion status according to claim 5, characterized in that, In step S5, an alarm is triggered based on the warning signal, and maintenance instructions are generated, including: When a Level 1 warning signal is received, a normal audible and visual alarm is triggered, and an operation and maintenance instruction is generated. The operation and maintenance instruction includes: increasing the sampling frequency of the sensor array, starting seabed topography scanning, and sending the risk location coordinates and real-time swing data to the operation and maintenance terminal. The swing data includes displacement, swing amplitude, and curvature. When a Level 2 emergency warning signal is received, a high-frequency pulse audible and visual alarm is triggered, and an emergency maintenance instruction is generated. The emergency maintenance instruction includes: controlling the generator set to reduce power to a safe threshold, initiating an underwater inspection pre-deployment procedure, and sending the maintenance coordinates and optimal navigation path to the nearest maintenance vessel.

7. A real-time motion state-based risk warning system for suspended submarine cables, used to implement the real-time motion state-based risk warning method for suspended submarine cables as described in any one of claims 1-6, characterized in that, The system includes the following modules: The data acquisition module is used to deploy a sensor array on the suspended section of the target submarine cable and use the sensor array to collect motion data of the target submarine cable, including attitude angle data, triaxial acceleration and triaxial angular velocity. Data processing module: connected to the data acquisition module, used to filter out the gravitational acceleration component from the triaxial acceleration based on the attitude angle data through coordinate transformation, and obtain the motion acceleration of the target submarine cable; Motion analysis module: connected to the data processing module, used to perform time-domain integration of the motion acceleration, calculate the displacement of the target submarine cable; combine the triaxial angular velocity and attitude angle data to reconstruct the three-dimensional spatial shape of the target submarine cable, and extract its swing amplitude and curvature; Risk warning module: connected to the motion analysis module, used to compare the swing amplitude with the safe swing amplitude threshold and the curvature with the safe curvature threshold in real time, and generate warning signals according to the warning rules based on the comparison results; Response execution module: connected to the risk warning block, used to trigger an alarm and generate operation and maintenance instructions based on the warning signal; Based on the triaxial angular velocity and attitude angle data, the three-dimensional spatial morphology of the target submarine cable is reconstructed, and its swing amplitude and curvature are extracted, including: S3b1. Using the sensor positions as nodes and the submarine cable segments between adjacent nodes as rigid links, construct the orientation rotation matrix in the local coordinate system based on the attitude angle data output by each sensor. S3b2. Taking the first node as the reference point, set the contact point P0 between the target submarine cable and the seabed. Based on the spacing between adjacent nodes and the direction rotation matrix, calculate the positions of subsequent nodes in sequence to obtain the coordinate sequence {P0, P1, ..., Pn} of the target submarine cable, where n is the number of nodes. S3b3. Based on the coordinate sequence, calculate the maximum instantaneous offset to obtain the swing amplitude; S3b4. Based on the coordinate sequence, generate a front vector and a back vector for each node, and calculate the local bending angle of the current node based on the front vector and the back vector, thereby obtaining the bending degree of the target submarine cable; the front vector is the vector between the current node and the previous node, and the back vector is the vector between the current node and the next node.

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