Stability control method for cement-based offshore floating structures based on dynamic water tank adjustment algorithm

Abstract

The present invention provides a stability control method for a cement-based offshore floating structure based on a dynamic water tank adjustment algorithm, which is applied to a dynamic water tank adjustment system for a cement-based offshore floating structure. The system includes a water tank module, a sensor network, an actuator, and a central control unit. The method includes the following operations: monitoring water level changes in the water tank module and shaking angle data of the cement-based offshore floating structure through the sensor network; the central control unit performs real-time analysis on the data collected by the sensor network, predicts the trend of wave load changes in the future, simulates the stress state of the structure, and generates a target water level value for the water tank module in combination with the structural material properties; and controls the actuator to adjust the water level of the water tank module according to the target water level value and the real-time water level value, so as to achieve stability control of the cement-based offshore floating structure. The present invention accurately matches water tank adjustment with material properties, avoids control failure or structural damage, and thereby improves structural stability.

Description

Technical Field

[0001] The present invention relates to the technical field of floating structure stability control, and in particular to a cement-based offshore floating structure stability control method based on a dynamic water tank adjustment algorithm. Background Art

[0002] As marine resource development extends to deep seas, cement-based composite materials are widely used in offshore floating platforms and floating wind turbine foundations due to their corrosion resistance and low cost. However, these structures, characterized by uniform mass distribution and low inherent damping, face significant stability control challenges in complex sea conditions. Current stability control technologies are mainly divided into three categories:

[0003] 1. Passive ballast adjustment technology: Adjusting the center of gravity using pre-placed ballast tanks is currently the most widely used stability control method. While this method is simple and highly reliable, it suffers from inherent shortcomings such as slow response speed and difficulty coping with rapid changes in wave loads. Particularly in extreme sea conditions such as typhoons, delayed ballast adjustment can easily lead to structural instability.

[0004] 2. Active dynamic balancing systems: These utilize hydraulically driven stabilizers or mechanical actuators such as adjustable buoyancy units to compensate for wave disturbances through real-time action. While they can effectively shorten response times in moderate sea conditions, their reliance on complex mechanical transmissions significantly increases offshore operation and maintenance difficulties and energy costs. For large, cement-based floating structures, especially those with a mass exceeding 1,000 tons, the system's energy efficiency plummets, limiting its effectiveness in stabilizing the system.

[0005] 3. Application of Intelligent Control Algorithms: Recently proposed algorithms such as adaptive PID control and fuzzy logic control attempt to improve stability control accuracy through dynamic feedback. However, traditional control models are not sufficiently adaptable to the nonlinear characteristics of wave loads, and are prone to cumulative control errors in scenarios involving large structures exceeding 100 meters in length or long-period irregular waves.

[0006] The shortcomings of the existing technical solutions mainly include the following aspects: First, the water tank control system with a concrete-based material structure still uses the steel structure adjustment logic, and the control parameters are not well matched; second, the passive system relying on the communicating vessel has a significant response delay, which makes it difficult to cope with sudden extreme sea conditions. The pipeline network structure is complex and the maintenance cost is high; third, the control algorithm does not fully consider the time-varying characteristics of dynamic wave loads, and the control accuracy is poor; fourth, the existing stability control solutions are mostly targeted at triangular platforms, and lack optimized applications for floating platforms of other shapes. Summary of the Invention

[0007] The object of the present invention is to provide a method for controlling the stability of cement-based offshore floating structures based on a dynamic water tank adjustment algorithm, so as to solve or at least partially solve the above-mentioned problems existing in the prior art.

[0008] To achieve the above objectives, the present invention provides the following technical solutions:

[0009] A method for controlling the stability of a cement-based offshore floating structure based on a dynamic water tank adjustment algorithm is disclosed. The method is applied to a dynamic water tank adjustment system for a cement-based offshore floating structure. The system includes a water tank module, a sensor network, an actuator, and a central control unit. The method includes the following operations:

[0010] Monitor water level changes in the water tank module and the rolling angle data of the cement-based offshore floating structure through a sensor network;

[0011] The central control unit analyzes the data collected by the sensor network in real time, predicts the trend of wave load changes in the future, simulates the structural stress state, and generates the target water level value of the water tank module based on the characteristics of the structural materials;

[0012] According to the target water level value and the real-time water level value, the control actuator adjusts the water level of the water tank module to achieve stability control of the cement-based offshore floating structure.

[0013] Furthermore, the water tank module includes a plurality of independent compartments distributed longitudinally and transversely along the cement-based offshore floating structure. The independent compartments include a main ballast compartment and an auxiliary compensation compartment. The main ballast compartment is arranged along the edge of the cement-based offshore floating structure and is used to undertake the main buoyancy adjustment task. The auxiliary compensation compartment is distributed in the geometric center area of the cement-based offshore floating structure and is used to adjust the center of gravity offset. The compartment wall of the independent compartment is prefabricated with cement-based materials. A conical drainage port is provided at the bottom of the independent compartment, and an actuator is provided at the top. The actuator is used to realize the injection and discharge of seawater.

[0014] Furthermore, the actuator includes an electromagnetic valve group, which includes a two-way control valve to form channel 1 and channel 2. Channel 1 is used to directly connect to the external seawater inlet through the top, and channel 2 is used to connect to the control channel of the drainage pipe at the bottom of the independent cabin.

[0015] Furthermore, the actuator performs the following operations when implementing seawater injection:

[0016] The electromagnetic valve group opens the valve in channel 1 and closes the valve in channel 2, allowing seawater to flow in naturally from the top seawater inlet under the action of gravity. The conical drainage port then acts as an exhaust channel, accelerating the exhaust of air in the cabin through the Venturi effect. When the sensor network monitors that the water level in the cabin has risen to the target height, the valve in channel 1 is closed.

[0017] The actuator performs the following operations when discharging seawater:

[0018] The electromagnetic valve group closes the valve of channel 1 and opens channel 2. The positive pressure in the cabin from the draft pressure of the cement-based offshore floating structure presses the water out of the conical drainage port. At this time, the valve of channel 1 is converted into an air intake compensation port.

[0019] Furthermore, the sensing network includes pressure sensors and inclination sensors. The pressure sensors are arranged at the bottom of each independent cabin for real-time monitoring of water level changes in the cabin; the inclination sensors are installed at the four corners and the center point of the cement-based offshore floating structure for dynamic collection of roll angle data and pitch angle data.

[0020] Furthermore, the central control unit adopts a multi-threaded parallel computing architecture and a built-in dynamic water tank adjustment algorithm, which includes:

[0021] The wave load prediction module is used to analyze the real-time data of the sensor network based on short-time Fourier transform, extract the wave spectrum characteristics and predict the load change trend in the future;

[0022] The stability compensation calculation module is used to simulate the stress state of cement-based offshore floating structures through finite element models. It combines the mechanical properties and micro-deformation characteristics of cement-based materials to dynamically generate the target water level values for each independent compartment of the water tank module.

[0023] The valve control strategy module is used to calculate the optimal valve opening combination and adjustment timing based on the difference between the target water level value and the real-time water level value, give priority to enabling the auxiliary compensation tank for rapid fine-tuning, and coordinate the main ballast tank to achieve buoyancy compensation. The control instructions are updated every 0.1 seconds and sent to the actuator.

[0024] Furthermore, the wave load prediction module is specifically used to predict the wave load change trend in the next 5 to 10 seconds in real time, providing a leading control basis for stability compensation, and ultimately obtaining the wave force amplitude-phase matrix in the future time window. It includes the following operations:

[0025] Short-time Fourier transform dynamic spectrum analysis: Real-time wave data is collected by wave height meters and accelerometers arranged around the structure. Short-time Fourier transform analysis is performed on the real-time wave data using a sliding time window to extract the distribution characteristics of wave energy in the frequency domain, especially the significant wave frequency band of 0.1-0.3 Hz. The autoregressive moving average model is combined to predict future wave sequences, and the model parameters are dynamically updated using the recursive least squares method to adapt to the non-stationary characteristics of the waves.

[0026] Deep learning algorithm modification: Train and deploy time series algorithms through experimental data, input historical wave spectra, structural motion responses and environmental data or networks, and output the time domain envelope of wave forces.

[0027] Furthermore, the stability compensation calculation module is specifically used to calculate the target water level of each independent compartment based on the wave prediction results, so that the restoring moment of the cement-based offshore floating structure dynamically balances the wave overturning moment, and finally obtains the target water level vector of each independent compartment. The specific operations include:

[0028] A hybrid finite element-lumped parameter model was constructed: a reduced-order finite element method was used to rapidly solve the structural motion equations. The structural motion characteristics derived from the wave force amplitude-phase matrix were input to obtain the transient motion response of the cement-based floating offshore structure. The water within the independent compartment was simplified into a spring-mass-damper system, and the center of gravity offset at different water levels was calculated using an equivalent pendulum model. Based on the creep model of the cement-based material, the elastic modulus attenuation coefficient was updated online according to the service life of the cement-based material.

[0029] The optimization algorithm solves the target water level: an optimization function is constructed, expressed as W = minimizing the residual of the overturning moment + the energy consumption penalty term for suppressing frequent valve operations, so that W is minimized. The model predictive control framework is used to solve the constrained optimization problem in each control cycle, expressed as:

[0030]

[0031] in, Indicates the prediction time domain step of predictive control, reflecting the algorithm's prediction of the future The wave moment and the restoring moment within a control cycle are optimized in a rolling manner. is the wave overturning moment, represents the restoring torque, Indicates the flow change of the water tank module, represents the absolute timestamp of the current time step, Indicates the future i The moment of a control cycle, Represents the energy consumption penalty coefficient, which is used to adjust the weight of suppressing frequent valve actions in the optimization objective.

[0032] Furthermore, the valve control strategy module is specifically used to convert the target water level into a specific valve action sequence, including the following operations:

[0033] Valve characteristic modeling and linearization: Through experimental calibration of the flow coefficient of each valve of the actuator, the mapping relationship between valve opening and flow is established;

[0034] Hierarchical control architecture implementation: The target water level difference and total required flow are calculated based on the target water level vector of each independent compartment obtained by the stability compensation calculation module, and the flow quota is allocated to each independent compartment according to the priority of the independent compartment.

[0035] Furthermore, when the sensor network detects that the roll angle of the cement-based offshore floating structure exceeds a safety threshold, the following operations are performed:

[0036] The central control unit activates the wave load prediction module, combining historical data with real-time spectrum analysis to determine the main source direction of the wave overturning moment;

[0037] The stability compensation calculation module generates water filling instructions for the corresponding side main ballast tank and drainage instructions for the opposite side independent compartment based on the structural center of gravity offset, and simultaneously activates the auxiliary compensation tank in the geometric center area for diagonal compensation;

[0038] The valve control strategy module decomposes the control instructions into specific valve opening and closing action sequences and sends them to the actuators.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] The method provided by the present invention is applied to the dynamic water tank adjustment system of a cement-based offshore floating structure. The method monitors the water level changes of the water tank module and the structural shaking angle data through a sensor network. The central control unit further analyzes the sensor network data to predict the wave load change trend in the future period, simulates the stress state of the structure, and enhances the adaptability of the control algorithm to nonlinear disturbances and time-varying characteristics. At the same time, based on the material parameter optimization control algorithm, it ensures that the water tank module adjustment is accurately matched with the mechanical properties of the cement-based material, avoids control failure or structural damage caused by parameter mismatch, and effectively improves the stability of the cement-based offshore floating structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 The present invention provides a method for controlling the stability of a cement-based offshore floating structure based on a dynamic water tank adjustment algorithm.

[0043] Figure 2 It is a schematic diagram of the cross-sectional structure of the dynamic water tank adjustment system provided by an embodiment of the present invention.

[0044] Figure 3 It is a schematic diagram of the sensor arrangement of the dynamic water tank adjustment system provided by an embodiment of the present invention.

[0045] Figure 4 It is a schematic diagram of the system dynamic adjustment process provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The principles and features of the present invention are described below with reference to the accompanying drawings. The enumerated embodiments are only used to explain the present invention and are not used to limit the scope of the present invention.

[0047] This embodiment provides a method for controlling the stability of a cement-based offshore floating structure based on a dynamic water tank adjustment algorithm. The method is implemented based on a dynamic water tank adjustment system for a cement-based offshore floating structure. The dynamic water tank adjustment system includes a water tank module, a sensor network, an actuator, and a central control unit. Figure 1 , the method includes the following operations:

[0048] S1. Monitor the water level changes in the water tank module and the shaking angle data of the cement-based offshore floating structure through the sensor network.

[0049] S2. The central control unit performs real-time analysis on the data collected by the sensor network, predicts the trend of wave load changes in the future, simulates the stress state of the structure, and generates the target water level value of the water tank module based on the characteristics of the structural materials.

[0050] S3. According to the target water level value and the real-time water level value, the actuator is controlled to adjust the water level of the water tank module to achieve stability control of the cement-based offshore floating structure.

[0051] Reference Figure 2-3 The water tank module includes a plurality of independent cabins distributed longitudinally and transversely along the cement-based offshore floating structure, and the independent cabins include a main ballast tank and an auxiliary compensation tank. The main ballast tank is arranged along the edge of the cement-based offshore floating structure, and its volume accounts for more than 70% of the entire water tank, and is used to undertake the main buoyancy adjustment task. The auxiliary compensation tank is distributed in the geometric center area of the cement-based offshore floating structure, and is used to fine-tune the center of gravity offset. It has a smaller volume but a faster response speed. The cabin wall of the independent cabin is prefabricated with ultra-high strength and ultra-tensile cement-based material. A conical drainage port is provided at the bottom of the independent cabin. Its main function is to ensure that the water flow forms laminar flow rather than turbulent flow when entering and exiting, thereby reducing energy loss. An actuator is provided on the top of the cabin, and the actuator is used to realize the injection and discharge of seawater.

[0052] In this embodiment, the actuator comprises a solenoid valve assembly, which includes a bidirectional control valve that forms Channel 1 and Channel 2. Channel 1 is directly connected to the external seawater inlet through the top, while Channel 2 is a control channel for connecting to the drainage pipe at the bottom of the independent compartment. The valve opening and closing angles are precisely controlled by a stepper motor to achieve graded flow regulation of seawater inflow and outflow.

[0053] The actuator performs the following operations when implementing seawater injection:

[0054] The electromagnetic valve group opens the valve of channel 1 and closes the valve of channel 2, allowing seawater to flow in naturally from the top seawater inlet under the action of gravity. The conical drainage port then serves as an exhaust channel, accelerating the discharge of air in the cabin through the Venturi effect. When the sensor network monitors that the water level in the cabin has risen to the target height, the valve of channel 1 is closed.

[0055] The actuator performs the following operations when discharging seawater:

[0056] The electromagnetic valve group closes the valve of channel 1 and opens the valve of channel 2. The positive pressure in the cabin from the draft pressure of the cement-based offshore floating structure presses the water out of the conical drainage port. At this time, the valve of channel 1 is converted into an air intake compensation port to avoid the formation of vacuum blocking drainage.

[0057] As a possible implementation method, the actuator adopts a redundant design, and the solenoid valve group of each independent compartment includes a main valve and a backup valve. The main valve is a large-diameter butterfly valve with a maximum flow rate of 50m³ / min, which is used for rapid injection and drainage. The backup valve is a precision ball valve with a flow regulation accuracy of ±2%, which is used for high-precision water level correction. The motor used to drive the valve is equipped with a torque feedback device for real-time monitoring of the valve status and feedback on whether the valve is stuck or leaking. At the same time, in order to reduce the temperature rise effect of the cavity inside the cement-based structure, the connection between the solenoid valve group and the pipeline is coated with a fiber insulation layer to ensure long-term operational reliability.

[0058] The sensor network comprises high-precision pressure and tilt sensors, embedded in an array at key locations within the structure. Pressure sensors are located at the bottom of each independent compartment to monitor water level changes in real time. Tilt sensors are installed at the four corners and center of the cement-based offshore floating structure to dynamically collect roll and pitch angle data. Data collected by all sensors is transmitted to a central control unit via a fiber optic network with a sampling frequency of at least 100 Hz to ensure millisecond-level response to wave loads.

[0059] The central control unit adopts a multi-threaded parallel computing architecture and has a built-in dynamic water tank adjustment algorithm. The dynamic water tank adjustment algorithm includes a wave load prediction module, a stability compensation calculation module, and a valve control strategy module.

[0060] The wave load prediction module is used to analyze the real-time data of the sensor network based on short-time Fourier transform, extract the wave spectrum characteristics and predict the load change trend in the next 5 to 10 seconds.

[0061] The stability compensation calculation module is used to simulate the stress state of cement-based offshore floating structures through a finite element model. It combines the mechanical properties and micro-deformation characteristics of cement-based materials to dynamically generate the target water level values of each independent compartment of the water tank module.

[0062] The valve control strategy module is used to calculate the optimal valve opening combination and adjustment timing based on the difference between the target water level value and the real-time water level value, give priority to enabling the auxiliary compensation tank for rapid fine-tuning, and coordinate the main ballast tank to achieve large-scale buoyancy compensation. The control instructions are updated every 0.1 seconds and sent to the actuator.

[0063] The core task of the wave load prediction module is to predict the wave load variation trend in real time within the next 5 to 10 seconds, providing a leading control basis for stability compensation. Ultimately, the wave force amplitude-phase matrix within the future time window is obtained. This module includes the following operations:

[0064] Short-time Fourier transform dynamic spectrum analysis: Real-time wave data is collected by wave height meters and accelerometers arranged around the structure. Short-time Fourier transform analysis is performed on the real-time wave data using a sliding time window to extract the distribution characteristics of wave energy in the frequency domain, especially the significant wave frequency band of 0.1-0.3 Hz. The autoregressive moving average model is combined to predict future wave sequences, and the model parameters are dynamically updated using the recursive least squares method to adapt to the non-stationary characteristics of the waves.

[0065] Deep learning algorithm modification: A time series algorithm is trained and deployed using experimental data, taking historical wave spectra, structural motion responses, and environmental data or networks as inputs, and outputting the time envelope of wave forces. For example, the time series algorithm can be a long short-term memory network or a Transformer.

[0066] The core task of the stability compensation calculation module is to calculate the target water level of each independent compartment based on the wave prediction results, so that the restoring moment of the cement-based offshore floating structure dynamically balances the wave overturning moment, and finally obtain the target water level vector of each independent compartment. The specific operations include the following:

[0067] A hybrid finite element-lumped parameter model is constructed: a reduced-order finite element method is used to rapidly solve the structural motion equations. Structural motion characteristics derived from the wave force amplitude-phase matrix—such as roll, pitch, and heave—are input to determine the instantaneous motion response of the cement-based floating offshore structure. The water within the independent compartment is simplified into a spring-mass-damper system, and the center of gravity offset at different water levels is calculated using an equivalent pendulum model. Based on a creep model for cement-based materials, the elastic modulus attenuation coefficient is updated online according to the service life of the cement-based material to achieve result correction.

[0068] The optimization algorithm solves the target water level: Construct an optimization function W, expressed as W = minimize the residual of the overturning moment + the energy consumption penalty term for suppressing frequent valve operations, so that W is minimized; use the model predictive control framework to solve the constrained optimization problem in each control cycle, expressed as:

[0069]

[0070] in, Indicates the prediction time domain step of predictive control, reflecting the algorithm's prediction of the future The wave moment and the restoring moment within a control cycle are optimized in a rolling manner. is the wave overturning moment, represents the restoring torque, Indicates the flow change of the water tank module, represents the absolute timestamp of the current time step, Indicates the future i The moment of a control cycle, Represents the energy consumption penalty coefficient, which is used to adjust the weight of suppressing frequent valve actions in the optimization objective. The larger it is, the more the system tends to reduce flow changes; otherwise, it prioritizes tracking torque balance. and All need to be calibrated in advance. In this embodiment, , .

[0071] The core task of the valve control strategy module is to convert the target water level into a specific valve action sequence, including the following operations:

[0072] Valve characteristic modeling and linearization: Through experimental calibration of the flow coefficient of each valve of the actuator, the mapping relationship between valve opening and flow is established;

[0073] A hierarchical control architecture is implemented: The target water level difference and total required flow rate are calculated based on the target water level vectors for each individual compartment, obtained by the stability compensation calculation module. Flow quotas are then allocated to each compartment based on their priority. For example, the main valve is used for coarse flow control, employing bang-bang control (fully open / fully closed) to shorten response time. The backup valve is used for fine flow control, employing PID control to suppress overshoot.

[0074] Reference Figure 4 The system dynamically adjusts the stability of the offshore floating structure based on the monitoring data of the sensor network. Specifically, when the sensor network detects that the roll angle of the cement-based offshore floating structure exceeds a safety threshold, the following operations are performed:

[0075] The central control unit activates the wave load prediction module, combining historical data with real-time spectrum analysis to determine the main source direction of the wave overturning moment;

[0076] The stability compensation calculation module generates water filling instructions for the corresponding side main ballast tank and drainage instructions for the opposite side independent compartment based on the structural center of gravity offset, and simultaneously activates the auxiliary compensation tank in the geometric center area for diagonal compensation;

[0077] The valve control strategy module decomposes the control instructions into specific valve opening and closing action sequences and sends them to the actuators.

[0078] For example, when a storm approaches, the main valve at the bottom of the target compartment is opened first for high-flow water injection. When the water level approaches the target value, the backup valve is switched to for fine-tuning. The entire process, from data collection to execution, is quick, effectively offsetting periodic disturbances caused by waves. Furthermore, the central control unit optimizes algorithm parameters based on historical adjustment records to gradually improve control efficiency under varying sea conditions.

[0079] As an alternative implementation, to accommodate diverse cement-based floating structures, the water tank modules utilize a design that combines standardized prefabrication with flexible configuration. For platforms of any regular shape, the main ballast tanks are symmetrically arranged along their perimeter, while auxiliary compensating tanks are positioned within the inner circle, near the center of gravity of the platform structure, and appropriately increase the initial mass. The volume and position parameters of all tanks can be dynamically adjusted based on the structural dimensions. The central control unit's topology recognition algorithm automatically selects the optimal control strategy.

[0080] As another optional implementation, a high-pressure air tank is added next to the main ballast tank of the water tank module, and the main ballast tank and the high-pressure air tank are connected by a solenoid reversing valve. When rapid drainage is required, the solenoid reversing valve is opened to inject compressed air from the high-pressure air tank into the main ballast tank, using the air pressure to accelerate the discharge of seawater through the conical drainage port, thereby increasing the drainage speed.

[0081] At the same time, the hydraulic control channel of the main valve / backup valve is retained for steady-state regulation. The pneumatic mode is only used for emergency response under sudden large wave impact. The pressure sensor is used to monitor the air tank-water tank pressure difference in real time to avoid overcompensation.

[0082] While retaining the core function of water tank regulation, this implementation incorporates an aerodynamic compensation mechanism, improving response speed through the synergistic effect of compressed air and seawater. Furthermore, during the pneumatic drainage phase, the discharged seawater can be used to drive a micro-turbine generator, recovering some of the energy for compressed air storage and reducing overall energy consumption.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for controlling the stability of cement-based offshore floating structures based on a dynamic water tank adjustment algorithm, characterized in that: The method is applied to a dynamic water tank adjustment system of a cement-based offshore floating structure, the system comprising a water tank module, a sensor network, an actuator, and a central control unit, and the method comprises the following operations: Monitor water level changes in the water tank module and the rolling angle data of the cement-based offshore floating structure through a sensor network; The central control unit analyzes the data collected by the sensor network in real time, predicts the trend of wave load changes in the future, simulates the structural stress state, and generates the target water level value of the water tank module based on the characteristics of the structural materials; According to the target water level value and the real-time water level value, the control actuator adjusts the water level of the water tank module to achieve stability control of the cement-based offshore floating structure; The water tank module includes multiple independent compartments distributed longitudinally and transversely along the cement-based offshore floating structure. The independent compartments include a main ballast compartment and an auxiliary compensation compartment. The main ballast compartment is arranged along the edge of the cement-based offshore floating structure and is used to perform the main buoyancy adjustment task. The auxiliary compensation compartment is distributed in the geometric center area of the cement-based offshore floating structure and is used to adjust the center of gravity offset. The compartment walls of the independent compartments are prefabricated with cement-based materials. The independent compartments are provided with a conical drainage port at the bottom and an actuator at the top for realizing seawater injection and discharge. The central control unit adopts a multi-threaded parallel computing architecture and a built-in dynamic water tank adjustment algorithm. The dynamic water tank adjustment algorithm includes: The wave load prediction module is used to analyze the real-time data of the sensor network based on short-time Fourier transform, extract the wave spectrum characteristics and predict the load change trend in the future; The stability compensation calculation module is used to simulate the stress state of cement-based offshore floating structures through finite element models. It combines the mechanical properties and micro-deformation characteristics of cement-based materials to dynamically generate the target water level values for each independent compartment of the water tank module. The valve control strategy module is used to calculate the optimal valve opening combination and adjustment timing based on the difference between the target water level value and the real-time water level value, activate the auxiliary compensation tank for rapid fine-tuning, and coordinate the main ballast tank to achieve buoyancy compensation. The control command is updated every 0.1 seconds and sent to the actuator; When the sensor network detects that the roll angle of the cement-based offshore floating structure exceeds the safety threshold, the following operations are performed: The central control unit activates the wave load prediction module, combining historical data with real-time spectrum analysis to determine the main source direction of the wave overturning moment; The stability compensation calculation module generates water filling instructions for the main ballast tank on the corresponding side and drainage instructions for the independent compartment on the opposite side based on the structural center of gravity offset, and simultaneously activates the auxiliary compensation tank in the geometric center area for diagonal compensation; The valve control strategy module decomposes the control instructions into specific valve opening and closing action sequences and sends them to the actuators.

2. The method according to claim 1, characterized in that The actuator includes an electromagnetic valve group, which includes a two-way control valve to form channel 1 and channel 2. Channel 1 is used to directly connect to the external seawater inlet through the top, and channel 2 is used to connect to the control channel of the drainage pipe at the bottom of the independent cabin.

3. The method according to claim 2, characterized in that The actuator performs the following operations when implementing seawater injection: The electromagnetic valve group opens the valve in channel 1 and closes the valve in channel 2, allowing seawater to flow in naturally from the top seawater inlet under the action of gravity. The conical drainage port then acts as an exhaust channel, accelerating the exhaust of air in the cabin through the Venturi effect. When the sensor network monitors that the water level in the cabin has risen to the target height, the valve in channel 1 is closed. The actuator performs the following operations when discharging seawater: The electromagnetic valve group closes the valve of channel 1 and opens channel 2. The positive pressure in the cabin from the draft pressure of the cement-based offshore floating structure presses the water out of the conical drainage port. At this time, the valve of channel 1 is converted into an air intake compensation port.

4. The method according to claim 1, wherein The sensor network includes pressure sensors and inclination sensors. The pressure sensors are arranged at the bottom of each independent cabin and are used to monitor the water level changes in the cabin in real time. The inclination sensors are installed at the four corners and the center point of the cement-based offshore floating structure and are used to dynamically collect roll angle data and pitch angle data.

5. The method according to claim 1, wherein The wave load prediction module is specifically used to predict the wave load change trend in the next 5 to 10 seconds in real time, providing a leading control basis for stability compensation, and ultimately obtaining the wave force amplitude-phase matrix in the future time window. It includes the following operations: Short-time Fourier transform dynamic spectrum analysis: Wave height meters and accelerometers placed around the structure collect real-time wave data. Short-time Fourier transform analysis is performed on the real-time wave data using a sliding time window to extract the distribution characteristics of wave energy in the frequency domain. Combined with the autoregressive moving average model to predict future wave sequences, the model parameters are dynamically updated through the recursive least squares method to adapt to the non-stationary characteristics of the waves; Deep learning algorithm modification: Train and deploy time series algorithms through experimental data, input historical wave spectra, structural motion responses and environmental data or networks, and output the time domain envelope of wave forces.

6. The method according to claim 5, characterized in that The stability compensation calculation module is specifically used to calculate the target water level of each independent compartment based on the wave prediction results, so that the restoring moment of the cement-based offshore floating structure dynamically balances the wave overturning moment, and finally obtains the target water level vector of each independent compartment. The specific operations include: A hybrid finite element-lumped parameter model was constructed: a reduced-order finite element method was used to rapidly solve the structural motion equations. The structural motion characteristics derived from the wave force amplitude-phase matrix were input to obtain the transient motion response of the cement-based floating offshore structure. The water within the independent compartment was simplified into a spring-mass-damper system, and the center of gravity offset at different water levels was calculated using an equivalent pendulum model. Based on the creep model of the cement-based material, the elastic modulus attenuation coefficient was updated online according to the service life of the cement-based material. The optimization algorithm solves the target water level: Construct an optimization function W, expressed as W = minimize the residual of the overturning moment + the energy consumption penalty term for suppressing frequent valve operations, so that W is minimized; use the model predictive control framework to solve the constrained optimization problem in each control cycle, expressed as: in, Indicates the prediction time domain step of predictive control, reflecting the algorithm's prediction of the future The wave moment and the restoring moment are optimized in rolling manner within a control cycle. is the wave overturning moment, represents the restoring torque, Indicates the flow change of the water tank module, represents the absolute timestamp of the current time step, Indicates the future i The moment of a control cycle, Represents the energy consumption penalty coefficient, which is used to adjust the weight of suppressing frequent valve actions in the optimization objective.

7. The method according to claim 6, characterized in that The valve control strategy module is specifically used to convert the target water level into a specific valve action sequence, including the following operations: Valve characteristic modeling and linearization: Through experimental calibration of the flow coefficient of each valve of the actuator, the mapping relationship between valve opening and flow is established; Hierarchical control architecture implementation: The target water level difference and total required flow are calculated based on the target water level vector of each independent compartment obtained by the stability compensation calculation module, and the flow quota is allocated to each independent compartment according to the priority of the independent compartment.

Images