Fan foundation erosion damage monitoring and repairing system based on external magnetic field and implementation method

Abstract

The invention discloses a draught fan foundation scouring damage monitoring and repairing system based on an external magnetic field. The draught fan foundation scouring damage monitoring and repairing system comprises an annular electromagnetic coil array, a multi-mode monitoring module, a repairing material putting device and a control center. The annular electromagnetic coil array is arranged on a surrounding seabed of a fan foundation, and the repairing material is guided to migrate to a scouring pit by dynamically regulating and controlling a magnetic field; the multi-mode monitoring module collects magnetic field, terrain and hydrological data. The repairing material putting device is used for putting a repairing material into the washing area; the control center establishes data communication or control signal connection with the annular electromagnetic coil array, the multi-mode monitoring module and the repair material putting device, receives monitoring data of the multi-mode monitoring module and sends a control instruction to the annular electromagnetic coil array and the repair material putting device. Real-time monitoring and closed-loop self-repairing of scouring damage are achieved, and the accuracy, stability and ecological compatibility of protection are improved.

Description

Technical Field

[0001] This invention relates to the field of marine engineering structure protection technology, specifically to a real-time monitoring and self-repair system and method for scour damage to structures such as offshore wind turbine foundations and underwater pile foundations of cross-sea bridges. Background Technology

[0002] Offshore wind turbine foundations, cross-sea bridge pile foundations, and other underwater structures are constantly subjected to ocean currents and waves, making them prone to seabed erosion, leading to decreased foundation bearing capacity and structural instability. Current mainstream protection technologies have significant drawbacks: 1. Sandbag / rockfill method: This method achieves protection by dumping sandbags, rocks, or precast concrete components, but it easily damages the anti-corrosion coating of the pile foundation during construction, triggering secondary erosion. Furthermore, construction in deep-sea areas is costly and lacks precision. 2. Biomimetic aquatic plant technology: This relies on flexible viscous damping to reduce flow velocity and promote sediment deposition, but it has high requirements for seabed geology, lacks stability in silty soils, and imported products are expensive. 3. Solidified soil technology: This technology forms a protective zone through the reaction of a solidifying agent with the soil, but it has poor durability, high cost, and the solidifying agent poses a risk of marine environmental pollution. In addition, non-magnetic repair agents in traditional technologies are prone to mispositioning in strong ocean currents, and the repair structure lacks structural stability under dynamic hydrodynamic loads, making it difficult to meet long-term protection requirements.

[0003] To address the aforementioned issues, Ludong University developed the "Pile Pupil" system, which uses a 16-dimensional distributed stress sensing array, vibration sensors, and flow velocity and water pressure sensors to achieve synchronous monitoring of the pile foundation across the entire circumference and multiple depths. The system collects data in real time and uses algorithms such as Kalman filtering, principal component analysis, and BP neural networks to accurately invert the depth of scour pits (with an error of less than 3%), and intelligently assesses the safety status of the pile foundation (such as issuing a warning that the scour depth exceeds 10% of the pile diameter). The application of this system, with its real-time monitoring and early warning capabilities, can help maintenance personnel predict scour risks in advance and avoid secondary scour caused by blind or insufficient filling. It can also assess the protective effect after filling, indirectly reducing the "blindness" of the filling method. It can monitor the scour status around the pile foundation in real time. If the bionic aquatic plant protection fails (such as a continuous increase in scour depth), the system can issue an early warning in time to help maintenance personnel take targeted measures. By monitoring changes in the depth of scour pits, it can indirectly determine the effectiveness of the solidified soil protection strip. However, the system relies on physical quantities such as stress, vibration, and hydrology to indirectly infer the scour status. It lacks active intervention modules such as magnetic field control and material delivery. It can only detect problems but cannot autonomously resolve scour damage. It requires subsequent manual or other repair system intervention, resulting in a disconnect between monitoring and repair.

[0004] The self-healing system of Huaneng Rudong Baxianjiao Offshore Wind Power Co., Ltd. collects suspended sediment using a net, stores it in a sand collection box, and transports it to the scour pit via a sand conveying pipe. Field application showed that after Typhoon Lekima passed, the system successfully collected approximately 50 cubic meters of sediment, filling a scour pit to a depth of 1.5 meters, restoring the seabed morphology, and effectively preventing the scour pit from expanding. The non-contact design of "net collection + sand conveying pipe" eliminates the need to throw hard objects onto the seabed; it simply transports natural sediment to the scour pit through pipes, completely avoiding disturbance to the pile foundation structure and anti-corrosion layer during construction, eliminating the risk of secondary damage. It utilizes only naturally occurring suspended sediment in the ocean as the repair material, without any chemical additives or hardeners, completely avoiding environmental pollution risks and demonstrating excellent ecological compatibility. The system's automatic operation eliminates the need for maintenance personnel to work at sea, reducing safety risks. However, the system relies on natural sediment resources and lacks an active monitoring mechanism. Its repair efficiency depends entirely on the amount of suspended sediment in the environment and it cannot accurately control the filling location and density. It can only perform passive repairs, cannot provide early warnings of erosion risks, and cannot cope with filling failures caused by insufficient sediment or strong ocean currents. As a result, its repair accuracy and stability are poor.

[0005] Existing automatic monitoring and repair systems for wind turbine foundation scour damage achieve a closed loop of "real-time monitoring - accurate assessment - timely repair" through a combination of multi-source sensing, intelligent decision-making, and ecological collaboration, effectively improving the operation and maintenance efficiency and safety of wind farms. However, challenges remain in areas such as monitoring accuracy and coverage, repair reliability and ecological sustainability, system integration and decision-making, and ecological compatibility and adaptability. Further improvements in system performance and reliability are needed through material innovation (such as durable biomimetic materials), algorithm optimization (such as multi-source data fusion), and system integration (such as real-time data sharing). Summary of the Invention

[0006] The technical problem to be solved by this invention is to address the above-mentioned shortcomings by providing a wind turbine foundation scour damage monitoring and repair system and implementation method based on an external magnetic field. This system addresses the defects of traditional protection technologies, such as large construction disturbances, inaccurate positioning of repair materials in strong ocean current environments, insufficient stability of the repair body under dynamic hydrodynamic loads, poor long-term durability, and potential marine environmental pollution. The system enables real-time monitoring and closed-loop self-repair of scour damage, thereby improving the accuracy, stability, and ecological compatibility of protection.

[0007] To solve the above technical problems, the present invention adopts the following technical solution: A wind turbine foundation scour damage monitoring and repair system based on an external magnetic field includes a ring electromagnetic coil array, a multimodal monitoring module, a repair material delivery device, and a control center. The ring electromagnetic coil array is deployed on the seabed surrounding the wind turbine foundation, and guides the repair material to migrate towards the scour pit by dynamically adjusting the magnetic field. The multimodal monitoring module collects magnetic field, topographic, and hydrological data. The repair material delivery device delivers repair material to the scour area. The control center establishes data communication or control signal connections with the ring electromagnetic coil array, the multimodal monitoring module, and the repair material delivery device, respectively, receives monitoring data from the multimodal monitoring module, and sends control commands to the ring electromagnetic coil array and the repair material delivery device.

[0008] Furthermore, the ring-shaped electromagnetic coil array can switch between static mode, dynamic mode, and gradient magnetic field mode under the control of the control center; The static mode applies a uniform magnetic field of 0.3T to make the initial magnetization of the repair material ≥20kA / m, which is applicable to conventional ocean current environments with a flow velocity <1.5m / s. The dynamic mode outputs an instantaneous pulse magnetic field with a peak value of 1.5T and a duration of 0.1s to resist extreme hydrological events with a flow velocity ≥3m / s and a wave height ≥8m. The gradient magnetic field mode generates a magnetic field potential well pointing towards the scour pit through independent coil current adjustment. It is used in the repair stage to guide the material migration by adjusting the coil current to generate a magnetic field potential well pointing towards the scour pit.

[0009] Furthermore, the ring-shaped electromagnetic coil array includes several electromagnetic coils, which are designed to be independently connected in parallel. Each group of coils is individually connected to the drive circuit of the control center through a shielded cable. The electromagnetic coils are arranged in a concentric circle array with a radius of 3-5m, matching the horseshoe-shaped vortex development characteristics around the monopile wind turbine foundation, so that the magnetic field coverage and scour-prone areas are precisely matched. The electromagnetic coils are fixed and supported by a titanium alloy frame and are embedded into the seabed by hydraulic penetration.

[0010] Furthermore, the multimodal monitoring module includes a three-axis fluxgate sensor, a multibeam echo sounder, and an acoustic Doppler current profiler. The three-axis fluxgate sensor, the multibeam echo sounder, and the acoustic Doppler current profiler are connected to the control center via a data bus. The number of the three-axis fluxgate sensors can be adjusted according to the diameter of the wind turbine foundation. The three-axis fluxgate sensors need to uniformly cover a 3-5m radius area around the wind turbine foundation. The multibeam echo sounder generates a digital elevation model of the seabed, and the acoustic Doppler current profiler measures the vertical flow velocity and calculates the shear stress.

[0011] Further, the repair material dispensing device is connected to the control center through a control signal, and adjusts the dispensing parameters according to the dispensing instructions of the control center; the repair material dispensed by the repair material dispensing device has a core-shell structure, with a magnetic particle core layer and an underwater curing system shell layer.

[0012] Further, the repair material dispensing device includes a pneumatic projector and a remotely operated underwater vehicle (ROV). Both the pneumatic projector and the ROV are connected to the control center through a wireless or wired control link; the initial velocity and range of the pneumatic projector are adjustable; the ROV is equipped with a multi-degree-of-freedom robotic arm, and a magnetic field-directed nozzle is integrated at the end. The cooperation of the pneumatic projector and the ROV covers the full-area repair from the surface layer to the deep layer.

[0013] Further, the control center includes a processor, a field programmable gate array, and a data transmission unit; the core algorithms of the control center include a multi-source fusion model for scouring volume and a material loss warning model. The multi-source fusion model for scouring volume is used to integrate multi-source data, and the material loss warning model is used to judge the stability of the repair body. The triggering conditions for the material loss warning are set based on the material loss rate and the loss rate.

[0014] An implementation method for a monitoring and repair system for scour damage of a wind turbine foundation based on an external magnetic field includes the following steps: Step 1, magnetic field baseline calibration and geological parameter initialization. The control center sends an activation instruction to the circular electromagnetic coil array to collect the initial magnetic field distribution ; obtain the seabed soil magnetic permeability through a penetration test 、magnetic permeability is the total magnetic anomaly change; Step 2, real-time diagnosis of scour damage. The multi-modal monitoring module transmits the collected magnetic field, terrain, and hydrological data to the control center; preliminary confirmation of scour damage. When the magnetic anomaly reaches a preset threshold and lasts for a preset duration, combined with the scour pit characteristics identified by sonar, it is preliminarily confirmed that there is effective scour damage; determination of the severity of damage and accurate calculation of the scour volume. Based on the acoustic Doppler current profiler data, calculate the local scour factor SF. By comparing SF with the risk threshold, determine the severity of the scour damage. When SF < 0.5, it is determined as a mild scour risk; when 0.5 < SF < 1, it is determined as a moderate scour risk; when SF > 1, it is judged as a severe scour risk; Step 3, dynamic regulation of repair materials. The control center sends a coil current adjustment instruction to the circular electromagnetic coil array according to the flow direction data of the acoustic Doppler current profiler, and at the same time sends a hierarchical dispensing instruction to the repair material dispensing device, and executes according to the surface pneumatic injection, middle-layer ROV medium-pressure filling, and bottom-layer ROV grouting processes; Step 4, Material Loss Monitoring and Self-Maintenance: Based on feedback data from the multimodal monitoring module, the control center monitors material loss through a steady-state loss model (long-term slow loss) and a sudden loss model (rapid loss caused by sudden strong water flow). When the material loss rate reaches a preset value, a replenishment command is sent to the repair material delivery device. The replenishment amount is set according to the preset ratio of the initial delivery amount.

[0015] Furthermore, the multimodal monitoring module continues to operate, transmitting the collected magnetic field, topographic, and hydrological data to the control center. The specific process is as follows: S211, a three-axis fluxgate sensor acquires real-time magnetic field data, compared with the initial magnetic field distribution. Comparative calculation of magnetic anomalies , B current These are real-time measured values; The local magnetic anomaly generated by the i-th magnetic repair material at the location of the triaxial fluxgate sensor is: ; Where: k is the permeability correction coefficient of the seabed medium, and M is the change in magnetic moment. Where χ is the magnetic susceptibility of the material, H is the magnetic field strength, and V is the volume of the repaired material. material Measured by the dispensing device, r is the distance from the triaxial fluxgate sensor to the pit edge. The angle between the direction of the magnetic field and the axis of the sensor; S212, a multibeam echo sounder, scans the seabed topography to generate a real-time digital elevation model (DEM) of the seabed and identifies the morphological characteristics of scour pits. The scour volume is calculated using an irregular triangular mesh algorithm: ; Where: z 0j For the initial elevation, z cj For the current elevation, real-time scanning data, formula , Calculated from the round-trip time of the sound wave, A j Let n be the area of ​​the triangular mesh, n be the total number of triangular meshes, and j be the mesh index, from 1 to n. S213, Acoustic Doppler velocity profiler for measuring vertical velocity distribution and calculating flow shear stress. ; ; ; Where: u is the friction velocity, k v Let z be the Kármán constant (0.4). r For seabed roughness, The density of seawater, Let z be the time-averaged flow velocity at height z.

[0016] Furthermore, the material loss rate The calculation formula is as follows: ; In the formula: M0 represents the initial amount of repair material released, calculated by the flow sensor on the release device, indicating the material loss rate. (Deployment speed) Time); M t Let be the amount of repair material remaining at time t; The material loss rate The calculation formula is as follows: ; In the formula: For the rate of material loss, , These represent the attrition rates at times t1 and t2, respectively; t2-t1 is the time interval. When the material loss early warning model triggers the warning condition, the control center automatically activates the incremental replenishment mode: sending a replenishment command to the repair material delivery device, according to the initial delivery amount. Add supplementary materials at the preset ratio Simultaneously, the ring-shaped electromagnetic coil array is regulated to generate a magnetic field adapted to the current hydrological environment, guiding the replenishment material to accurately cover the lost area and maintain the integrity of the restoration.

[0017] The present invention adopts the above technical solution and has the following technical effects compared with the prior art: This invention reduces disturbance to the wind turbine foundation and anti-corrosion layer during construction through the embedded design of a ring-shaped electromagnetic coil array, avoiding secondary damage. Utilizing magnetic field gradients and dynamic control mechanisms, it significantly improves the positioning accuracy of repair materials in complex ocean currents and wave environments, reducing the risk of material loss. A multi-modal monitoring module integrates magnetic field, topographic, and hydrological data, enabling real-time perception and accurate diagnosis of scour damage, providing a reliable basis for repair decisions. The combination of core-shell structure repair materials and layered repair processes enhances the structural stability and long-term durability of the repaired body under dynamic hydrodynamic loads, extending the protection period. A control center coordinates the collaborative operation of all modules, constructing a closed-loop management system of "monitoring-diagnosis-repair-maintenance," improving overall protection efficiency. Simultaneously, it avoids the use of traditional curing agents and other materials, reducing the risk of marine environmental pollution and better meeting the needs of marine ecological protection. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0019] Figure 1 This is a flowchart of the present invention. Figure 2 This is a schematic diagram of the structure of the present invention; In the diagram, 1-electromagnetic coil, 2-acoustic Doppler velocity profiler, 3-triaxial fluxgate sensor, 4-fan foundation, and 5-control center. Detailed Implementation

[0020] Examples, such as Figure 2 As shown, a wind turbine foundation scour damage monitoring and repair system based on an external magnetic field includes a ring electromagnetic coil array, a multimodal monitoring module, a repair material delivery device, and a control center 5. The ring electromagnetic coil array is deployed on the seabed surrounding the wind turbine foundation 4, and guides the repair material to migrate towards the scour pit by dynamically adjusting the magnetic field. The multimodal monitoring module collects magnetic field, topographic, and hydrological data. The repair material delivery device delivers repair material to the scour area. The control center establishes data communication or control signal connections with the ring electromagnetic coil array, the multimodal monitoring module, and the repair material delivery device, respectively, receives monitoring data from the multimodal monitoring module, and sends control commands to the ring electromagnetic coil array and the repair material delivery device.

[0021] By constructing a system consisting of a "ring electromagnetic coil array + multimodal monitoring module + repair material delivery device + control center", the control center serves as the core, establishing data communication or control signal connections with the other three components. It receives magnetic field, topographic, and hydrological data collected by the multimodal monitoring module, analyzes and judges the scour damage status, and then sends magnetic field control commands to the ring electromagnetic coil array (guiding the migration of repair materials). At the same time, it sends delivery commands to the repair material delivery device (precisely replenishing materials), forming a closed-loop control of "monitoring-diagnosis-repair-maintenance".

[0022] The ring-shaped electromagnetic coil array, under the control of the central control unit, can switch between static, dynamic, and gradient magnetic field modes. This multi-mode magnetic field control mechanism ensures stable positioning of the material under normal conditions while resisting extreme hydrodynamic loads. In static mode, a uniform magnetic field of 0.3T is applied, resulting in an initial magnetization of the repair material ≥20kA / m, suitable for conventional ocean current environments with flow velocities <1.5m / s. In dynamic mode, a transient pulse magnetic field with a peak value of 1.5T and a duration of 0.1s is output to resist extreme hydrological events with flow velocities ≥3m / s and wave heights ≥8m. The gradient magnetic field, through the adjustment of 16 sets of independent coil currents with an accuracy of ±0.5A, generates a magnetic potential well pointing towards the scour pit, used during the repair phase. By adjusting the coil current, a magnetic potential well pointing towards the scour pit is generated, guiding material migration. All these modes change the magnetic field strength by altering the current.

[0023] The annular electromagnetic coil array uses a titanium alloy TC4 frame with a tensile strength ≥895MPa and a seawater corrosion resistance grade CCA ≥5. It is embedded into the seabed to a depth ≥0.5m using a hydraulic penetration device to ensure anti-overturning stability in a highly sensitive silt layer with a sensitivity St>4.

[0024] The ring-shaped electromagnetic coil array includes several electromagnetic coils 1. The electromagnetic coils 1 adopt an independent parallel design. Each group of coils is individually connected to the drive circuit of the control center 5 through a shielded cable to achieve precise current regulation (accuracy ±0.5A) and avoid crosstalk.

[0025] The electromagnetic coils 1 are arranged in a concentric circular array with a radius of 3-5m based on CFD analysis of the seabed flow field. This arrangement matches the horseshoe-shaped vortex development characteristics around the monopile wind turbine foundation, ensuring that the magnetic field coverage precisely corresponds to the areas prone to scour. A titanium alloy frame (tensile strength ≥895MPa) is used to fix and support the electromagnetic coils. This frame serves as a support structure to fix and protect the coils. Hydraulic penetration embeds the coils into the seabed to a depth of ≥0.5m to ensure the anti-overturning stability of the annular electromagnetic coil array in silty geology (sensitivity St>4).

[0026] The embedded design of the titanium alloy frame avoids damage to the anti-corrosion layer of the wind turbine foundation and solves the problem of large disturbance during construction using the traditional dumping method; the magnetic field mode can be dynamically switched to adapt to complex environments ranging from regular ocean currents to extreme hydrological events, improving the adaptability of magnetic field control; the concentric circle layout ensures effective coverage of the magnetic field in key scour areas and improves material guiding efficiency.

[0027] The multimodal monitoring module is used to transmit the collected magnetic field data, topographic data and hydrological data to the control center in real time; the real-time transmission of monitoring data ensures that the control center can obtain the scour status in a timely manner, solving the problem of lag in traditional monitoring.

[0028] The multimodal monitoring module includes a triaxial fluxgate sensor 3, a multibeam echo sounder, and an acoustic Doppler current profiler 2. The number of triaxial fluxgate sensors can be adjusted according to the diameter of the wind turbine foundation. The triaxial fluxgate sensors need to uniformly cover a radius area of ​​3-5m around the wind turbine foundation. If the diameter of the wind turbine foundation is ≥10m, the number of triaxial fluxgate sensors can be 16 sets. The 16 sets of triaxial fluxgate sensors cover a certain range around the wind turbine foundation according to a preset layout. The 16 sets of triaxial fluxgate sensors and 16 sets of electromagnetic coils are spatially corresponding. The triaxial fluxgate sensors are located between the electromagnetic coils 1 and are used to monitor changes in the magnetic field gradient. If the diameter of the wind turbine foundation is <10m, the number of triaxial fluxgate sensors can be selected as 12 sets. The triaxial fluxgate sensors are mainly deployed in scour-prone areas (such as horseshoe vortex areas). The location is optimized through CFD flow field analysis to ensure full coverage of magnetic anomaly detection.

[0029] The multibeam echo sounder generates a digital seabed elevation model, and the acoustic Doppler current profiler measures vertical current velocity and calculates shear stress. All sensors in the multimodal monitoring module are connected to the control center via a data bus. The collaborative use of multiple sensor types covers multidimensional parameters including magnetic field, topography, and hydrodynamics, solving the problem of insufficient accuracy with single monitoring methods. The triaxial fluxgate sensor 3, multibeam echo sounder, and acoustic Doppler current profiler 2 are connected to the control center 5 via a data bus. This data bus connection ensures the consistency and timeliness of data transmission, providing the control center with comprehensive and reliable decision-making information and improving the accuracy of scour damage diagnosis.

[0030] The repair material dispensing device is connected to the control center via control signals, and adjusts dispensing parameters (such as speed and flow rate) according to the dispensing instructions from the control center. The repair material dispensed by the device has a core-shell structure, with magnetic particles as the core layer and an underwater solidification system as the outer shell. The magnetic core of the core-shell structure repair material is directionally migrated by a magnetic field, and the underwater solidification shell rapidly solidifies after dispensing to form a stable repair body. The particle size is adapted to the Stokes settling law to reduce loss caused by water erosion, thereby improving material utilization and reducing protection costs.

[0031] The repair material delivery device includes a pneumatic projector and a remotely operated vehicle (ROV). Both the projector and ROV utilize existing technology and are connected to a control center via wireless or wired control links. The pneumatic projector's initial velocity and range are adjustable. The ROV is equipped with a multi-degree-of-freedom robotic arm with a magnetic field-oriented nozzle integrated at its end. The combined operation of the pneumatic projector and ROV covers the entire repair area from the surface to the depths, solving the problem that traditional single-delivery methods are difficult to adapt to complex scour patterns. The multi-degree-of-freedom robotic arm and directional nozzle improve the positioning accuracy of deep repairs, ensuring a tight fit between the repaired material and the scour pit, and enhancing protective stability.

[0032] The control center 5 receives monitoring data from the multimodal monitoring module through a data interface, processes it through a built-in algorithm to generate control commands, and sends them to the ring electromagnetic coil array and the repair material delivery device through a drive circuit. The hardware of the control center includes a processor, a field-programmable gate array, and a data transmission unit. The core algorithms include a scour volume multi-source fusion model and a material loss early warning model. The scour volume multi-source fusion model is used to integrate multi-source data, and the material loss early warning model is used to determine the stability of the repair. The material loss early warning trigger condition is set based on the material loss rate and loss speed.

[0033] The control center receives multimodal monitoring data via a data interface. This data is then processed by a processor and a field-programmable gate array (FPGA) for rapid response. Control commands are generated using a multi-source fusion model of scour volume and a material loss early warning model. These commands are then sent to the ring electromagnetic coil array and the repair material delivery device via a drive circuit. The data transmission unit ensures interference-resistant communication by employing existing spread spectrum communication technology (such as DSSS), adding error correction coding (Reed-Solomon code), and using shielded cable wiring to meet the IEEE 802.3 interference resistance standard. While not unique to this invention, the transmission protocol has been optimized for the marine environment.

[0034] like Figure 1 As shown, a method for implementing a wind turbine foundation scour damage monitoring and repair system based on an external magnetic field includes the following steps: Step 1, Magnetic field baseline calibration and geological parameter initialization: The control center sends an activation command to the ring-shaped electromagnetic coil array, activating the electromagnetic coils to generate a magnetic field and collecting the initial magnetic field distribution under scour-free conditions. This serves as a benchmark for subsequent magnetic anomaly detection; The physical properties of seabed soil were obtained through penetration tests, with a focus on obtaining magnetic permeability parameters. Version 1.01, Silt-like Soil Setting 0.98; The control center will distribute the initial magnetic field. magnetic permeability , To flush out volume changes, To determine the total magnetic anomaly change, a mathematical correspondence between the magnetic field change and the scour volume is established, providing a computational basis for subsequent scour volume inversion and laying the groundwork for future applications of the multi-source fusion model of scour volume.

[0035] Step 2, Real-time diagnosis of scour damage: S21, the multimodal monitoring module continues to operate, transmitting the collected magnetic field, topographic, and hydrological data to the control center: S211, a three-axis fluxgate sensor acquires real-time magnetic field data, compared with the initial magnetic field distribution. Compare the calculated magnetic anomaly ΔB. B current These are real-time measured values; The local magnetic anomaly generated by the i-th magnetic repair material at the location of the triaxial fluxgate sensor is: ; Where: k is the magnetic permeability correction coefficient of the seabed medium (k=1.02 for sand, k=0.87 for silt), and M is the change in magnetic moment. Where χ is the magnetic susceptibility of the material, H is the magnetic field strength, and V is the volume of the repaired material. material Measured by the dispensing device, r is the distance from the triaxial fluxgate sensor to the pit edge. The angle between the direction of the magnetic field and the axis of the sensor.

[0036] S212, a multibeam echo sounder, scans the seabed topography. The multibeam echo sounder has a frequency of 200kHz and a beam opening angle of 120°, generating a real-time digital elevation model (DEM) of the seabed and identifying the morphological characteristics of scour pits (such as outline, depth, and extent). The scour volume is calculated using the Triangular Irregular Network (TIN) algorithm: ; Where: z 0j The initial elevation (obtained from the DEM model via multibeam sonar baseline scanning), z cj For the current elevation, real-time scanning data, formula , Calculated from the round-trip time of the sound wave, A j is the area of ​​the triangular mesh, n is the total number of triangular meshes, and j is the mesh index (1 to n).

[0037] S213, Acoustic Doppler velocity profiler (ADCP, operating frequency 600kHz), measures vertical velocity distribution and calculates water flow shear stress. ; ; ; Where: u is the friction velocity, k v Let z be the Kármán constant (0.4). r For seabed roughness, The density of seawater, Let z be the time-averaged flow velocity at height z.

[0038] S22, Preliminary scour damage confirmed: The control center receives magnetic field, topographic, and hydrological data, and detects magnetic anomalies. Scour pits that exceed a preset threshold (e.g., 5%) and last for a preset duration (e.g., 5 minutes), and whose depth or volume identified by multi-beam sonar reaches a preset value, are directly identified by the real-time seabed digital elevation model DEM. The preset depth value: mild scour is 0.5 m, moderate scour is 1.0 m, and severe scour is 1.5 m. The preset volume value is set according to the base diameter D, such as , and initially confirm effective scour damage.

[0039] S23, determination of damage severity and accurate calculation of scour volume: The control center calls the multi-source fusion model of scour volume, and based on the Bayesian network, fuses the scour volume V magnetic inverted by the magnetic field with the V acoustic calculated by the multi-beam sonar. The formula is . The weights w1 and w2 are obtained through training with historical data to achieve accurate accounting of the scour volume and provide the core basis for the dosage of repair materials.

[0040] Calculate the water flow shear stress by combining the flow velocity data measured by the acoustic Doppler current profiler , and combine it with the preset critical shear stress of the seabed soil to calculate the local scour factor SF: ; By comparing SF with the risk threshold, determine the severity of the scour damage. When SF < 0.5, it is judged as a mild scour risk; when 0.5 < SF < 1, it is judged as a moderate scour risk; when SF > 1, it is judged as a severe scour risk.

[0041] Step 3, dynamic regulation of repair materials: The control center sends a coil current adjustment command to the annular electromagnetic coil array according to the scour direction, scope diagnosed in step 2 and the flow direction data measured by the acoustic Doppler current profiler: by activating the electromagnetic coil corresponding to the scour pit, adjust the current intensity through the PID control algorithm to generate a gradient magnetic field adapted to the water flow direction (such as increasing the magnetic field intensity against the water flow direction) to offset the offset force of the ocean current on the material. Use the PID control algorithm to adjust the current intensity I = I_base + ΔI, where ΔI is dynamically calculated based on the flow velocity data.

[0042] At the same time, the control center sends a layered placement command to the repair material placement device: Surface layer: Control the pneumatic projector to spray the repair material on the surface layer of the scour pit at an initial velocity of 5 m / s and a range of 3 - 8 m to form an anti-scour shell with a thickness ≥ 0.3 m; Middle layer: Control the remotely operated underwater vehicle to fill the middle layer of the scour pit at a medium pressure with a flow velocity of 1 m / s through a multi-degree-of-freedom robotic arm to ensure that the porosity of the repair body < 30%; Bottom layer: The remotely operated vehicle is controlled to inject grout precisely into the suspended area at the bottom of the scour pit through a magnetic field directional nozzle at a flow rate of 0.3 m / s to repair the weak areas of the foundation. During deployment, the ring-shaped electromagnetic coil array continuously uses the magnetic field to pull and repair the magnetic core of the material, ensuring that the material accurately gathers in the target area under ocean current conditions. At the same time, the multi-modal monitoring module provides real-time data feedback, supporting the control of the magnetic field and the adjustment of deployment parameters.

[0043] Step 4, Material Loss Monitoring and Self-Maintenance: The multimodal monitoring module continuously tracks the status of the restoration: a three-axis fluxgate sensor monitors changes in the magnetic field distribution of the restoration area (inverting material aggregation), a multibeam sonar scans changes in the topography of the restoration (identifying loss areas), and an acoustic Doppler flow profiler records the impact intensity of water flow on the restoration. The control center invokes the material loss early warning model, and based on time series analysis, calculates the material loss rate using both a steady-state loss model (representing slow, long-term loss) and a sudden loss model (representing rapid loss due to sudden strong water flow). and churn rate ; ; In the formula: M0 represents the initial amount of repair material released, calculated by the flow sensor on the release device, indicating the material loss rate. (Deployment speed) Time); M t The remaining amount of repair material at time t (calculated through magnetic field distribution inversion or terrain scanning).

[0044] Material loss rate calculation: ; In the formula: Material loss rate (% / min) , t1 and t2 are the loss rates at times t1 and t2, respectively; t2-t1 is the time interval.

[0045] When the material loss early warning model triggers the early warning condition (such as η>15%), or When the rate exceeds 5% / min, the control center automatically activates the incremental replenishment mode: sending a replenishment command to the repair material dispensing device, dispensing material according to the initial dispensing amount. Supplementary materials are added at a preset ratio (e.g., 20%). Simultaneously, the ring electromagnetic coil array is regulated to generate a magnetic field adapted to the current hydrological environment, guiding the replenishment material to accurately cover the lost area, maintaining the integrity of the restoration, and realizing closed-loop management of "monitoring-diagnosis-repair-maintenance".

[0046] The description of this invention is given for illustrative and descriptive purposes only and is not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of the invention and to enable those skilled in the art to understand the invention and design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A wind turbine foundation scour damage monitoring and repair system based on an external magnetic field, characterized in that: The system includes a ring electromagnetic coil array, a multimodal monitoring module, a repair material delivery device, and a control center (5). The ring electromagnetic coil array is deployed on the seabed surrounding the wind turbine foundation (4) and guides the repair material to migrate to the scour pit by dynamically adjusting the magnetic field. The multimodal monitoring module collects magnetic field, topographic, and hydrological data. The repair material delivery device delivers repair material to the scour area. The control center establishes data communication or control signal connections with the ring electromagnetic coil array, the multimodal monitoring module, and the repair material delivery device, respectively, receives monitoring data from the multimodal monitoring module, and sends control commands to the ring electromagnetic coil array and the repair material delivery device.

2. The wind turbine foundation scour damage monitoring and repair system based on an external magnetic field according to claim 1, characterized in that: The ring electromagnetic coil array can switch between static mode, dynamic mode and gradient magnetic field mode under the control of the control center. The static mode applies a uniform magnetic field of 0.3T to make the initial magnetization of the repair material ≥20kA / m, which is applicable to conventional ocean current environments with a flow velocity <1.5m / s. The dynamic mode outputs an instantaneous pulse magnetic field with a peak value of 1.5T and a duration of 0.1s to resist extreme hydrological events with a flow velocity ≥3m / s and a wave height ≥8m. The gradient magnetic field mode generates a magnetic field potential well pointing towards the scour pit through independent coil current adjustment. It is used in the repair stage to guide the material migration by adjusting the coil current to generate a magnetic field potential well pointing towards the scour pit.

3. The wind turbine foundation scour damage monitoring and repair system based on an external magnetic field according to claim 1, characterized in that: The ring electromagnetic coil array includes several electromagnetic coils (1). The electromagnetic coils (1) are designed to be independently connected in parallel. Each group of coils is connected to the drive circuit of the control center (5) through a shielded cable. The electromagnetic coils (1) are arranged in a concentric circle array with a radius of 3-5m, matching the horseshoe-shaped vortex development characteristics around the single-pile wind turbine foundation (4), so that the magnetic field coverage and the scour-prone area are precisely matched. The electromagnetic coils (1) are fixed and supported by a titanium alloy frame and embedded into the seabed by hydraulic penetration.

4. The wind turbine foundation scour damage monitoring and repair system based on an external magnetic field according to claim 1, characterized in that: The multimodal monitoring module includes a three-axis fluxgate sensor (3), a multibeam sonar, and an acoustic Doppler current profiler (2). The three-axis fluxgate sensor (3), the multibeam sonar, and the acoustic Doppler current profiler (2) are connected to the control center (5) via a data bus. The number of the three-axis fluxgate sensors can be adjusted according to the diameter of the wind turbine foundation (4). The three-axis fluxgate sensors need to uniformly cover the area with a radius of 3-5m around the wind turbine foundation (4). The multibeam echo sounder generates a digital elevation model of the seabed, and the acoustic Doppler current profiler measures the vertical velocity and calculates the shear stress.

5. The wind turbine foundation scour damage monitoring and repair system based on an external magnetic field according to claim 1, characterized in that: The repair material dispensing device is connected to the control center via a control signal, and adjusts the dispensing parameters according to the dispensing command from the control center. The repair material dispensed by the repair material dispensing device has a core-shell structure, with the core layer being magnetic particles and the outer shell being an underwater solidification system.

6. The wind turbine foundation scour damage monitoring and repair system based on an external magnetic field according to claim 1, characterized in that: The repair material delivery device includes a pneumatic projector and a remotely operated underwater vehicle (ROV). Both the pneumatic projector and the ROV are connected to the control center through a wireless or wired control link; the initial velocity and range of the pneumatic projector are adjustable; the ROV is equipped with a multi-degree-of-freedom robotic arm, and a magnetic field-oriented nozzle is integrated at the end. The coordination of the pneumatic projector and the ROV covers the full-area repair from the surface layer to the deep layer.

7. The wind turbine foundation scour damage monitoring and repair system based on an external magnetic field according to claim 1, characterized in that: The control center includes a processor, a field-programmable gate array (FPGA), and a data transmission unit; the core algorithms of the control center include a multi-source fusion model for scouring volume and a material loss warning model. The multi-source fusion model for scouring volume is used to integrate multi-source data, and the material loss warning model is used to judge the stability of the repair body. The triggering conditions for material loss warning are set based on the material loss rate and the loss rate.

8. A method for implementing a wind turbine foundation scour damage monitoring and repair system based on an external magnetic field, characterized in that: The implementation method is applied to the external magnetic field-based monitoring and repair system for scour damage of a wind turbine foundation as described in any one of claims 1-7, and includes the following steps: Step 1: Magnetic field baseline calibration and geological parameter initialization. The control center sends an activation command to the ring electromagnetic coil array to collect the initial magnetic field distribution. The magnetic permeability of seabed soil was obtained through penetration tests. magnetic permeability This represents the total change in magnetic anomaly. Step 2, real-time diagnosis of scour damage. The multi-modal monitoring module transmits the collected magnetic field, terrain, and hydrological data to the control center; preliminary confirmation of scour damage. When the magnetic anomaly reaches a preset threshold and lasts for a preset duration, combined with the characteristics of the scour pit identified by sonar, it is preliminarily confirmed that there is effective scour damage; determination of the severity of damage and accurate calculation of the scouring volume. Based on the data of the acoustic Doppler current profiler (ADCP), the local scour factor SF is calculated. By comparing SF with the risk threshold, the severity of the scour damage is determined. When SF < 0.5, it is determined as a mild scour risk; when 0.5 < SF < 1, it is determined as a moderate scour risk; when SF > 1, it is judged as a severe scour risk. Step 3, dynamic regulation of repair materials. The control center sends a coil current adjustment instruction to the annular electromagnetic coil array according to the flow direction data of the ADCP, and at the same time sends a layered delivery instruction to the repair material delivery device, and executes the process of pneumatic injection on the surface layer, medium-pressure filling by the ROV in the middle layer, and grouting by the ROV at the bottom layer. Step 4, material loss monitoring and self-maintenance. Based on the feedback data of the multi-modal monitoring module, the control center monitors the material loss through a steady-state loss model of long-term slow loss and a mutation loss model of rapid loss caused by sudden strong water flow. When the material loss rate reaches a preset value, a replenishment instruction is sent to the repair material delivery device, and the replenishment amount is set according to a preset ratio of the initial delivery amount.

9. The implementation method of the wind turbine foundation scour damage monitoring and repair system based on an external magnetic field according to claim 8, characterized in that: The specific process of the multi-modal monitoring module continuously operating and transmitting the collected magnetic field, terrain, and hydrological data to the control center is as follows: S211, a three-axis fluxgate sensor acquires real-time magnetic field data, compared with the initial magnetic field distribution. Comparative calculation of magnetic anomalies , B current These are real-time measured values; The local magnetic anomaly generated by the i-th magnetic repair material at the position of the monitoring triaxial fluxgate sensor is: ； Where: k is the permeability correction coefficient of the seabed medium, and M is the change in magnetic moment. Where χ is the magnetic susceptibility of the material, H is the magnetic field strength, and V is the volume of the repaired material. material Measured by the dispensing device, r is the distance from the triaxial fluxgate sensor to the pit edge. The angle between the direction of the magnetic field and the axis of the sensor; S212, the multi-beam bathymetric sonar scans the seabed terrain, generates a real-time seabed digital elevation model (DEM), and identifies the morphological characteristics of the scour pit; The irregular triangulation algorithm is used to calculate the scouring volume: ； Where: z 0j For the initial elevation, z cj For the current elevation, real-time scanning data, formula , Calculated from the round-trip time of the sound wave, A j Let n be the area of ​​the triangular mesh, n be the total number of triangular meshes, and j be the mesh index, from 1 to n. S213, Acoustic Doppler velocity profiler for measuring vertical velocity distribution and calculating flow shear stress. ; ； ； Where: u is the friction velocity, k v Let z be the Kármán constant. r For seabed roughness, The density of seawater, Let z be the time-averaged flow velocity at height z.

10. The implementation method of the wind turbine foundation scour damage monitoring and repair system based on an external magnetic field according to claim 8, characterized in that: The material loss rate The calculation formula is as follows: ； In the formula: To address the material loss rate; The initial total amount of repair materials dispensed is accumulated via the flow sensor of the dispensing device. (Deployment speed) Time); M t Let t be the amount of repair material remaining. The material loss rate The calculation formula is as follows: ； In the formula: For the rate of material loss, , These represent the attrition rates at times t1 and t2, respectively; t2-t1 is the time interval. When the material loss early warning model triggers the warning condition, the control center automatically activates the incremental replenishment mode: sending a replenishment command to the repair material delivery device, according to the initial delivery amount. Add supplementary materials at the preset ratio Simultaneously, the ring-shaped electromagnetic coil array is regulated to generate a magnetic field adapted to the current hydrological environment, guiding the replenishment material to accurately cover the lost area and maintain the integrity of the restoration.

Images