A real-time control and monitoring system for a controllable pitch propeller of a ship

Abstract

The application discloses a kind of real-time control and monitoring system of ship controllable pitch propeller, it is related to ship engineering technical field, including construction module is used to calculate load disturbance pre-judgment value using load disturbance observation model, load disturbance pre-judgment value is converted into feedforward instruction, adjustment module is used to adjust the pitch angle of ship controllable pitch propeller according to feedforward instruction, compensation module is used to calculate the final moment residual error signal of ship controllable pitch propeller hydraulic actuator, correction module is used to update dynamic correction coefficient in load disturbance observation model, obtain final correction parameter, the present application is introduced into closed loop calibration mechanism and online correction algorithm, according to final moment residual error signal, dynamically corrected coefficient is updated in real time, according to the residual error signal of actual hydraulic pressure and theoretical pressure, model parameter is automatically adjusted, by the sensitivity analysis based on gradient change rate to dynamically adjust step, can identify and lock parameter abnormal mutation in time, greatly enhance the safety and reliability of system.

Description

Technical Field

[0001] This invention relates to the field of marine engineering technology, and in particular to a real-time control and monitoring system for a ship's controllable pitch propeller. Background Technology

[0002] In recent years, as the main carriers of global trade and transportation, the performance of ship propulsion systems directly affects navigation safety, economy, and environmental indicators. As a propulsion device, controllable pitch propellers can adapt to different navigation conditions by adjusting the propeller pitch angle, thereby changing ship speed and adjusting thrust without changing the main engine speed. This makes controllable pitch propellers highly adaptable and flexible in various complex sea conditions and changing operational requirements. With the continuous improvement of ship automation and intelligence, increasingly higher requirements are placed on the response speed, control accuracy, and stability of controllable pitch propeller control systems.

[0003] Currently, Chinese invention patent application number CN202410071754.X discloses an adaptive control method and device, including: determining the hydrostatic resistance of a ship and environmental data of the ship during navigation; determining a resistance coefficient based on the hydrostatic resistance and environmental data; determining the ship's first speed and load capacity; determining control parameters from a ship navigation database based on the first speed, load capacity, and resistance coefficient; and adjusting the ship's propeller speed and pitch ratio based on the control parameters to achieve ship propulsion. Thus, by using the drag coefficient to determine control parameters to control ship propulsion, the ship can adapt to complex operating conditions during navigation, improve the efficiency of the main engine, and reduce energy consumption. However, in existing technologies, load disturbance observation models that rely solely on preset model parameters cannot accurately capture the dynamic characteristics differences caused by changes in wake fraction, thrust deduction coefficient, and seawater density. This leads to deviations in feedforward commands and reduces control accuracy. Existing technologies lack effective online self-correction mechanisms. When the model experiences parameter drift due to environmental changes or long-term operation, it cannot automatically adjust model parameters based on the residual signal between actual hydraulic pressure and theoretical pressure, resulting in a decline in control performance over time. Existing correction algorithms ignore the sensitivity differences in error changes and cannot dynamically adjust the step size based on the rate of change of the gradient, which can easily cause oscillations or slow convergence during the correction process. Furthermore, they lack necessary parameter limiting and fault monitoring functions. Once abnormal changes occur in parameters, it is difficult to identify and lock them in time, thereby reducing the safety and reliability of the system. Summary of the Invention

[0004] The technical problem solved by this invention is that load disturbance observation models that rely solely on preset model parameters are unable to accurately capture the differences in dynamic characteristics caused by changes in wake fraction, thrust reduction coefficient, and seawater density, resulting in deviations in feedforward commands and reduced control accuracy. Existing technologies lack effective online self-correction mechanisms. When the model experiences parameter drift due to environmental changes or long-term operation, it cannot automatically adjust model parameters based on the residual signal between actual hydraulic pressure and theoretical pressure, leading to a decline in control performance over time. Existing correction algorithms ignore the sensitivity differences in error changes and cannot dynamically adjust the step size based on the rate of change of the gradient, which easily causes oscillations or slow convergence during the correction process. Furthermore, they lack necessary parameter limiting and fault monitoring functions. Once abnormal changes occur in parameters, it is difficult to identify and lock them in time, thereby reducing the safety and reliability of the system.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a real-time control and monitoring system for ship controllable pitch propellers, comprising a construction module, an adjustment module, a compensation module, and a correction module;

[0006] The construction module is used to construct a load disturbance observation model, calculate load disturbance prediction values ​​using the load disturbance observation model, and convert the load disturbance prediction values ​​into feedforward instructions;

[0007] The adjustment module is used to adjust the pitch angle of the ship's controllable pitch propeller according to the feedforward command;

[0008] The compensation module is used to calculate the difference between the current hydraulic pressure value and the theoretical hydraulic pressure value of the ship's controllable pitch propeller hydraulic actuator after adjusting the pitch angle, and obtain the final torque residual signal.

[0009] The correction module is used to establish a closed-loop calibration mechanism. It determines whether to trigger the correction process based on the final moment residual signal. When the correction process is triggered, it performs online correction on the load disturbance observation model, updates the dynamic correction coefficients in the load disturbance observation model, obtains the final correction parameters, and feeds them back to the load disturbance observation model.

[0010] As a preferred embodiment of the real-time control and monitoring system for ship controllable pitch propellers described in this invention, the construction module includes a data acquisition unit, a monitoring unit, and a construction unit.

[0011] The acquisition unit is used to acquire real-time rotational speed, real-time torque, and current speed data of the ship's main engine through different sensors.

[0012] The different sensors include a speed sensor, a torque sensor, and a tachometer;

[0013] The monitoring unit is used to take the real-time speed and real-time torque as input parameters and calculate the current actual propulsion power of the ship's main engine using a power calculation formula.

[0014] The construction unit is used to construct a load disturbance observation model, obtain the pitch angle setting value of the ship's controllable pitch propeller, and obtain the theoretical power of the spectrum from the preset load characteristic spectrum based on the pitch angle setting value and the current speed data.

[0015] The mathematical formula for the load disturbance observation model is:

[0016] ;

[0017] in, This indicates the predicted load disturbance value. This indicates the actual propulsion power. This indicates the pitch angle setting value. This indicates the current speed data. Indicates the theoretical power of the spectrum. Indicates the dynamic correction factor;

[0018] The calculation logic for the dynamic correction coefficient includes:

[0019] Based on a pre-set ship parameter database, read the wake fraction coefficient, thrust reduction coefficient, and seawater density correction coefficient corresponding to the current speed data;

[0020] The dynamic correction coefficient is obtained by weighting and fusing the wake fraction coefficient, thrust deduction coefficient, and seawater density correction coefficient.

[0021] The predicted load disturbance value is mapped to a hydraulic flow demand command through a preset flow mapping table, and the hydraulic flow demand command is used as a feedforward command.

[0022] As a preferred embodiment of the real-time control and monitoring system for ship controllable pitch propellers described in this invention, the adjustment module includes a parsing unit and a control unit;

[0023] The analysis unit is used to receive the feedforward command, extract data from the feedforward command, obtain the flow rate value in the feedforward command, use the flow rate value as the instantaneous target flow rate of the hydraulic actuator of the ship, and convert the instantaneous target flow rate into the target valve core position of the hydraulic valve of the hydraulic actuator according to the preset valve core curve.

[0024] The control unit is used to obtain the real-time valve core position of the hydraulic valve, compare the target valve core position with the real-time valve core position to obtain the position error, calculate the control current signal required by the hydraulic valve through a closed-loop control algorithm based on the position error, adjust the valve core opening of the hydraulic valve through the control current signal, and drive the hydraulic actuator to adjust the pitch angle of the ship's controllable pitch propeller.

[0025] As a preferred embodiment of the real-time control and monitoring system for ship controllable pitch propellers described in this invention, the compensation module includes a pressure detection unit and a processing unit.

[0026] The pressure detection unit is used to collect the current hydraulic pressure value of the hydraulic actuator in real time through a high-precision pressure sensor installed in the ship's hydraulic circuit after the pitch angle adjustment is completed.

[0027] The processing unit is used to calculate the theoretical driving torque based on the pitch angle setting value and the real-time rotation speed, and convert the theoretical driving torque into a theoretical hydraulic pressure value;

[0028] The current hydraulic pressure value is subtracted from the theoretical hydraulic pressure value to obtain the initial torque residual signal. The initial torque residual signal is then low-pass filtered to obtain the final torque residual signal.

[0029] As a preferred embodiment of the real-time control and monitoring system for ship controllable pitch propellers described in this invention, the correction module includes a calibration unit, a correction unit, an adjustment unit, a limiting unit, and an alarm unit.

[0030] The calibration unit is used to establish a closed-loop calibration mechanism and determine whether to trigger the correction process based on the final torque residual signal.

[0031] The correction unit is used to perform online correction of the load disturbance observation model after triggering the correction process;

[0032] The online correction includes gradient calculation and step size adjustment.

[0033] As a preferred embodiment of the ship controllable pitch propeller real-time control and monitoring system described in this invention, the logic for establishing the closed-loop calibration mechanism includes:

[0034] The final torque residual signal is used as a feedback input and input into the parameter update loop of the load disturbance observation model;

[0035] In the parameter update loop, a threshold determination is performed on the final torque residual signal;

[0036] When the final torque residual signal is greater than the preset error threshold, the load disturbance observation model is determined to be invalid, and the correction process is triggered.

[0037] When the final torque residual signal is less than or equal to the preset error threshold, it is determined that the load disturbance observation model has not failed, the current parameters of the load disturbance observation model remain unchanged, and the correction process is not triggered.

[0038] As a preferred embodiment of the real-time control and monitoring system for ship controllable pitch propellers described in this invention, the logic for gradient calculation includes:

[0039] A preset disturbance is applied to the dynamic correction coefficient within the load disturbance observation model. The difference between the final torque residual signal before and after the preset disturbance is applied is calculated. The ratio of the numerical difference to the preset disturbance is calculated, and the ratio is used as the gradient information of the final torque residual signal with respect to the dynamic correction coefficient.

[0040] The logic for adjusting the step size includes:

[0041] Read the numerical sign of the gradient information. If the gradient information is positive, determine that the step size direction is the direction in which the parameter decreases.

[0042] If the gradient information is negative, then the step size direction is determined to be the direction in which the parameter increases;

[0043] The gradient change rate of the gradient information over time is obtained, and the gradient change rate is compared with different sensitivity ranges to determine the sensitivity range of the gradient change rate.

[0044] Obtain the sensitivity level corresponding to the sensitivity range;

[0045] Based on the sensitivity level, obtain the corresponding step size adjustment coefficient from the preset step size mapping table;

[0046] The sensitivity range includes a first range, a second range, and a third range;

[0047] The sensitivity levels include a first level, a second level, and a third level;

[0048] Among them, the first interval corresponds to the first level, the second interval corresponds to the second level, and the third interval corresponds to the third level;

[0049] When the gradient change rate is less than or equal to the first threshold, the sensitivity range of the gradient change rate is determined to be the first range;

[0050] When the gradient change rate is greater than a first threshold and less than a second threshold, the sensitivity range of the gradient change rate is determined to be the second range;

[0051] When the gradient change rate is greater than or equal to the second threshold, the sensitivity range of the gradient change rate is determined to be the third range;

[0052] The dynamic correction step size is calculated by multiplying the absolute value of the gradient information by the step size adjustment coefficient.

[0053] The correction sign is determined based on the step direction;

[0054] If the step size direction is the direction in which the parameter decreases, then the correction sign is negative;

[0055] If the step size direction is the direction in which the parameter increases, then the correction sign is positive;

[0056] The correction amount is obtained by multiplying the correction sign with the dynamic correction step size.

[0057] The correction amount is added to the value of the dynamic correction coefficient to obtain the final correction coefficient.

[0058] As a preferred embodiment of the ship controllable pitch propeller real-time control and monitoring system of the present invention, the adjustment unit is used to stop online correction of the load disturbance observation model when the absolute value of the final torque residual signal is less than a preset dead zone threshold.

[0059] As a preferred embodiment of the ship controllable pitch propeller real-time control and monitoring system described in this invention, the limiting unit is used to constrain the final correction coefficient.

[0060] The logic of the constraints includes:

[0061] If the final correction coefficient is greater than or equal to the preset dynamic correction coefficient upper limit, then the preset dynamic correction coefficient upper limit is used as the final correction coefficient after amplitude limiting.

[0062] If the final correction coefficient is less than or equal to the preset lower limit of the dynamic correction coefficient, then the preset lower limit of the dynamic correction coefficient is used as the final correction coefficient after the amplitude is limited.

[0063] If the final correction coefficient is greater than the preset lower limit of the dynamic correction coefficient and less than the preset upper limit of the dynamic correction coefficient, then the final correction coefficient will be directly used as the final correction coefficient after the amplitude is limited.

[0064] As a preferred embodiment of the real-time control and monitoring system for ship controllable pitch propellers described in this invention, the alarm unit is used to calculate the parameter change rate of the final correction coefficient after amplitude limiting over time.

[0065] The rate of change of the parameter is compared with a preset mutation threshold;

[0066] When the rate of change of parameters is detected to be greater than the preset mutation threshold, the system is determined to have an abnormal fault, and the parameters of the current load disturbance observation model are locked, while a fault alarm signal is output.

[0067] The beneficial effects of this invention are as follows: By introducing a closed-loop calibration mechanism and an online correction algorithm, this invention effectively solves the problem that load disturbance observation models are unable to accurately capture the dynamic characteristic differences caused by changes in wake fraction, thrust reduction coefficient, and seawater density. It can update the dynamic correction coefficient in real time based on the final torque residual signal, eliminating the deviation of feedforward commands and improving the control accuracy of the system. It can automatically adjust the model parameters according to the residual signal between the actual hydraulic pressure and the theoretical pressure, compensating for parameter drift caused by environmental changes or long-term operation, and ensuring long-term stable control performance. By dynamically adjusting the step size through sensitivity analysis based on the gradient rate of change, it avoids the problems of oscillation or slow convergence in the correction process, optimizes the parameter update efficiency, and, in conjunction with the setting of the limiting unit and alarm unit, can promptly identify and lock abnormal parameter changes, greatly enhancing the safety and reliability of the system. Attached Figure Description

[0068] Figure 1 This is a basic flowchart of a real-time control and monitoring system for a ship's controllable pitch propeller, provided as an embodiment of the present invention. Detailed Implementation

[0069] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0070] Reference Figure 1 As an embodiment of the present invention, a real-time control and monitoring system for ship controllable pitch propellers is provided, including a construction module, an adjustment module, a compensation module and a correction module;

[0071] The construction module is used to build a load disturbance observation model, calculate the predicted load disturbance value using the load disturbance observation model, and convert the predicted load disturbance value into a feedforward command;

[0072] The adjustment module is used to adjust the pitch angle of the ship's controllable pitch propeller according to the feedforward command;

[0073] The compensation module is used to calculate the difference between the current hydraulic pressure value and the theoretical hydraulic pressure value of the hydraulic actuator of the ship's controllable pitch propeller after adjusting the pitch angle, and obtain the final torque residual signal.

[0074] The correction module is used to establish a closed-loop calibration mechanism. It determines whether to trigger the correction process based on the final moment residual signal. When the correction process is triggered, it performs online correction on the load disturbance observation model, updates the dynamic correction coefficients in the load disturbance observation model, obtains the final correction parameters, and feeds them back to the load disturbance observation model.

[0075] An adaptive control architecture based on deep integration of feedforward commands and closed-loop feedback was established, which realizes real-time and precise control of the pitch angle of the ship's controllable propeller. It can actively calculate the predicted value of load disturbance and quickly convert it into execution commands. At the same time, it uses the final moment residual signal to trigger the online correction process in real time, ensuring continuous output of optimal control parameters. This greatly improves the adaptability of the propulsion system to complex sea conditions and achieves the unity of high dynamic response and high steady-state accuracy of pitch angle adjustment.

[0076] The building module includes a data acquisition unit, a monitoring unit, and a building unit;

[0077] The data acquisition unit is used to collect real-time speed, real-time torque, and current speed data of the ship's main engine through different sensors;

[0078] Different sensors include speed sensors, torque sensors, and tachometers;

[0079] The monitoring unit is used to take real-time speed and real-time torque as input parameters and calculate the current actual propulsion power of the ship's main engine through the power calculation formula;

[0080] The construction unit is used to build a load disturbance observation model, obtain the pitch angle setting value of the ship's controllable pitch propeller, and obtain the theoretical power of the spectrum from the preset load characteristic spectrum based on the pitch angle setting value and the current speed data.

[0081] The mathematical formula for the load disturbance observation model is:

[0082] ;

[0083] in, This indicates the predicted load disturbance value. Indicates actual propulsion power. This indicates the pitch angle setting value. This indicates the current speed data. Indicates the theoretical power of the spectrum. Indicates the dynamic correction factor;

[0084] The calculation logic for the dynamic correction factor includes:

[0085] Based on a pre-set ship parameter database, read the wake fraction coefficient, thrust reduction coefficient, and seawater density correction coefficient corresponding to the current speed data;

[0086] The dynamic correction coefficient is obtained by weighted fusion of the wake fraction coefficient, thrust reduction coefficient, and seawater density correction coefficient.

[0087] The predicted load disturbance value is mapped to a hydraulic flow demand command through a preset flow mapping table, and the hydraulic flow demand command is used as a feedforward command.

[0088] The dynamic correction coefficients are updated online adaptively by the correction module based on the real-time moment residual signal.

[0089] The load disturbance observation model is constructed based on the ship propeller open-water test pattern and propulsion characteristic curve. The pattern is stored in the system's non-volatile memory and contains thrust coefficient and torque coefficient data under different advance coefficients.

[0090] Dynamic correction coefficient It is a dimensionless parameter calculated in real time, used to quantify the hydrodynamic differences caused by the interaction between the hull and the propeller. Through a preset ship parameter database, it reads the wake fraction coefficient, thrust reduction coefficient, and seawater density correction coefficient corresponding to the current speed in real time.

[0091] The weighted fusion algorithm uses a linear weighting method, where the wake fraction coefficient is assigned a weight of 0.5, the thrust deduction coefficient is assigned a weight of 0.3, and the seawater density correction coefficient is assigned a weight of 0.2. The dynamic correction coefficient is obtained by calculating the weighted sum of these three parameters. .

[0092] The preset flow mapping table is a three-dimensional lookup table. The horizontal axis represents the predicted load disturbance value, and the vertical axis represents the current hydraulic oil temperature. The lookup result is the required hydraulic flow demand command. This table has been precisely calibrated through bench testing to ensure the accuracy of converting electrical signals into hydraulic drive commands.

[0093] The preset load characteristic graph is set to include a three-dimensional correspondence between pitch angle, speed and main engine torque.

[0094] The preset ship parameter database is set to include the mapping relationship of wake fraction coefficient, thrust reduction coefficient and seawater density correction coefficient. Its setting is mainly based on the measured data of ship tank test, the empirical formula of ITTC international recommended standard and the seawater salinity and temperature characteristics of the navigation area. It aims to provide accurate physical environment basic data support for the calculation of dynamic correction coefficient by storing the calibration values ​​of hydrodynamic parameters under different speeds, drafts and sea states.

[0095] A high-precision mathematical model incorporating dynamic correction coefficients was constructed. By integrating the wake fraction, thrust reduction coefficient, and seawater density correction coefficient, the dynamic correction coefficients calculated in real time can accurately reflect the complex and ever-changing characteristics of the marine environment. This ensures that the predicted load disturbance values ​​are highly consistent with the actual operating conditions, and the generated hydraulic flow demand commands are highly forward-looking, eliminating the negative impact of environmental factors on control accuracy.

[0096] The adjustment module includes a resolution unit and a control unit;

[0097] The parsing unit is used to receive feedforward commands, extract data from the feedforward commands, obtain the flow rate value in the feedforward commands, use the flow rate value as the instantaneous target flow rate of the ship's hydraulic actuator, and convert the instantaneous target flow rate into the target valve core position of the hydraulic valve of the hydraulic actuator according to the preset valve core curve.

[0098] The control unit is used to obtain the real-time valve core position of the hydraulic valve, compare the target valve core position with the real-time valve core position to obtain the position error, and calculate the control current signal required by the hydraulic valve through a closed-loop control algorithm based on the position error. The valve core opening of the hydraulic valve is adjusted by the control current signal, and the hydraulic actuator is driven to adjust the pitch angle of the ship's controllable pitch propeller.

[0099] The preset valve core curve is set as a physical characteristic curve that describes the nonlinear relationship between the valve core displacement and the flow rate of the hydraulic valve.

[0100] The closed-loop control algorithm adopts an incremental PID control strategy. Its proportional coefficient is set to 2.5 according to the response frequency band of the hydraulic system, the integral time constant is set to 0.1 seconds to eliminate steady-state error, and the derivative time constant is set to 0.01 seconds to suppress valve core oscillation.

[0101] The instantaneous target flow rate represents the hydraulic oil volume flow rate required to overcome the current hydrodynamic load and achieve the desired pitch angle change rate.

[0102] The control unit reads the real-time valve core position fed back by the high-precision displacement sensor at a 1-millisecond cycle, compares it with the target valve core position, and calculates the control current signal. After power amplification, the signal drives the proportional electromagnet to adjust the valve core opening of the hydraulic valve in real time, ensuring that the hydraulic actuator can accurately track the flow command and achieve rapid and error-free adjustment of the pitch angle.

[0103] By precisely mapping the flow rate value to the position of the hydraulic valve core and eliminating position errors in real time through a closed-loop control algorithm, the instantaneous target flow rate of the hydraulic actuator is accurately tracked. This control strategy based on dual closed loops of flow rate and position gives the system extremely fast response speed and extremely high positioning accuracy, ensuring that the opening degree of the hydraulic valve core strictly follows the feedforward command, effectively overcoming the inherent hysteresis effect of the hydraulic system, and ensuring the timeliness and accuracy of pitch angle adjustment.

[0104] The compensation module includes a pressure detection unit and a processing unit;

[0105] After the pitch angle adjustment is completed, the pressure detection unit collects the current hydraulic pressure value of the hydraulic actuator in real time through a high-precision pressure sensor installed in the ship's hydraulic circuit.

[0106] The processing unit is used to calculate the theoretical driving torque based on the pitch angle setting and real-time rotational speed, and convert the theoretical driving torque into a theoretical hydraulic pressure value;

[0107] The current hydraulic pressure value is subtracted from the theoretical hydraulic pressure value to obtain the initial torque residual signal. The initial torque residual signal is then low-pass filtered to eliminate high-frequency hydraulic pulsation interference, resulting in the final torque residual signal.

[0108] When calculating the theoretical hydraulic pressure value, the hydrodynamic torque acting on the blade is first calculated based on the hydrodynamic characteristic curve of the controllable pitch propeller, combined with the current pitch angle setting and real-time speed. Then, the friction torque of the blade bearing and the inertial torque of the counterweight mechanism are superimposed to obtain the total theoretical driving torque. Finally, this torque is divided by the effective working area of ​​the hydraulic cylinder of the hydraulic actuator to derive the theoretical hydraulic pressure value.

[0109] The low-pass filtering process uses a second-order active low-pass filter with a cutoff frequency set to 5 Hz.

[0110] The difference between the current hydraulic pressure value and the theoretical hydraulic pressure value is calculated and low-pass filtering is introduced to successfully obtain a smooth and accurate final torque residual signal. This method effectively filters out high-frequency noise interference in the hydraulic circuit and eliminates the interference of signal fluctuations on the judgment logic, providing high-quality data support for subsequent model correction and ensuring that the control system can make accurate decisions based on real and reliable state information.

[0111] The correction module includes a calibration unit, a correction unit, an adjustment unit, a limiting unit, and an alarm unit;

[0112] The calibration unit is used to establish a closed-loop calibration mechanism between feedforward prediction and actual feedback, and determines whether to trigger the correction process based on the final torque residual signal;

[0113] The correction unit is used to perform online correction of the load disturbance observation model after the correction process is triggered;

[0114] Online correction includes gradient calculation and step size adjustment.

[0115] By establishing a closed-loop calibration mechanism through calibration and correction units and introducing gradient calculation and step size adjustment logic, the optimal correction magnitude can be automatically calculated according to the error change trend. This not only significantly accelerates the convergence speed of model parameters but also effectively avoids overshoot and oscillation during the correction process, ensuring that the load disturbance observation model always remains in the best working state.

[0116] The logic for establishing a closed-loop calibration mechanism includes:

[0117] The final torque residual signal is used as feedback input to the parameter update loop of the load disturbance observation model;

[0118] Threshold determination is performed on the final torque residual signal in the parameter update loop;

[0119] When the final torque residual signal is greater than the preset error threshold, the load disturbance observation model is determined to be faulty, and the correction process is triggered.

[0120] When the final torque residual signal is less than or equal to the preset error threshold, it is determined that the load disturbance observation model has not failed, the current parameters of the load disturbance observation model remain unchanged, and the correction process is not triggered.

[0121] The preset error threshold is set to 0.6 MPa.

[0122] By comparing the final torque residual signal with a preset error threshold, the timing of correction triggering is determined, thus constructing an intelligent fault-tolerant range. The correction process is only initiated when the model error exceeds the allowable range. This on-demand correction strategy effectively suppresses the impact of measurement noise on model stability, avoids frequent and meaningless parameter adjustments, significantly reduces the system's computational burden, and ensures the smooth operation of the control process.

[0123] The logic for gradient calculation includes:

[0124] Apply a preset disturbance to the dynamic correction coefficients within the load disturbance observation model, calculate the difference between the final torque residual signals before and after applying the preset disturbance, calculate the ratio of the numerical difference to the preset disturbance, and use the ratio as the gradient information of the final torque residual signal with respect to the dynamic correction coefficients.

[0125] The preset disturbance amount is set to 0.01.

[0126] The logic for step size adjustment includes:

[0127] Read the numerical sign of the gradient information. If the gradient information is positive, then determine that the step size direction is the direction in which the parameter decreases.

[0128] If the gradient information is negative, then the step size direction is determined to be the direction in which the parameter increases;

[0129] Obtain the gradient change rate of gradient information over time, compare the gradient change rate with different sensitivity ranges, and determine the sensitivity range of the gradient change rate.

[0130] Obtain the sensitivity level corresponding to the sensitivity range;

[0131] Based on the sensitivity level, obtain the corresponding step size adjustment coefficient from the preset step size mapping table;

[0132] The preset step size mapping table is set to store the data table corresponding to the step size adjustment coefficients for different sensitivity ranges.

[0133] The sensitivity range includes the first range, the second range, and the third range;

[0134] Sensitivity levels include Level 1, Level 2, and Level 3;

[0135] Among them, the first interval corresponds to the first level, the second interval corresponds to the second level, and the third interval corresponds to the third level;

[0136] When the gradient rate of change is less than or equal to the first threshold, the sensitivity range for determining the gradient rate of change is the first range;

[0137] When the gradient rate of change is greater than the first threshold and less than the second threshold, the sensitivity range for determining the gradient rate of change is the second range.

[0138] When the gradient rate of change is greater than or equal to the second threshold, the sensitivity range for determining the gradient rate of change is the third range.

[0139] Different sensitivity levels correspond to different step size adjustment coefficients, and the higher the sensitivity level, the smaller the corresponding step size adjustment coefficient.

[0140] The first threshold is set to 0.05, and the second threshold is set to 0.2.

[0141] When the gradient rate of change is less than or equal to 0.05, it is classified as the first interval, indicating that the error changes gradually and the system is in a stable convergence phase. At this time, the sensitivity level is the first level, and the step size adjustment coefficient is 1.0. When the gradient rate of change is between 0.05 and 0.2, it is classified as the second interval, indicating that the system is in a rapid approximation phase, and the step size adjustment coefficient is 2.0. When the gradient rate of change is greater than or equal to 0.2, it is classified as the third interval, indicating that the error changes drastically and there may be strong external disturbances. The step size adjustment coefficient is 0.5 to prevent overshoot.

[0142] The dynamic correction step size is calculated by multiplying the absolute value of the gradient information by the step size adjustment coefficient.

[0143] The correction sign is determined based on the step size direction;

[0144] If the step size direction is the direction in which the parameter decreases, then the correction sign is negative;

[0145] If the step size direction is the direction in which the parameter increases, then the correction sign is positive;

[0146] The correction amount is obtained by multiplying the correction sign with the dynamic correction step size.

[0147] The correction amount is added to the value of the dynamic correction coefficient to obtain the final correction coefficient.

[0148] Ensure that the parameter correction process proceeds in the direction of reducing the amplitude of the torque residual signal, thereby achieving online correction of the observation model.

[0149] By dividing the sensitivity range and dynamically mapping the step size adjustment coefficient, a variable step size control strategy based on the gradient change rate is realized, which makes the correction process both fast and robust. It can quickly approach the target value when the error is large and perform fine-tuning when the error is small, thus solving the contradiction between convergence speed and stability. Combined with the accurate calculation of gradient sign and correction amount, it ensures that the model parameters always evolve rapidly along the optimal path.

[0150] The adjustment unit is used to stop online correction of the load disturbance observation model when the absolute value of the final torque residual signal is less than the preset dead zone threshold.

[0151] The preset dead zone threshold is set to 0.3 MPa.

[0152] This dead-zone control logic eliminates the limit cycle oscillation phenomenon near the equilibrium point of the system, which not only significantly reduces the computational load of the microprocessor, but also avoids frequent operation of the hydraulic valve under small errors, thus significantly reducing the energy consumption and component wear of the hydraulic system.

[0153] By introducing a preset dead zone threshold through the adjustment unit, the correction stops when the absolute value of the final torque residual signal is small, eliminating the limit loop oscillation phenomenon near the stable point of the system. This design makes the control output of the hydraulic actuator more stable, avoids frequent small vibrations of the valve core near the equilibrium position, significantly reduces the wear of mechanical parts, and extends the service life of the hydraulic control system.

[0154] The limiting unit is used to constrain the final correction coefficient;

[0155] The logic of the constraints includes:

[0156] If the final correction coefficient is greater than or equal to the preset dynamic correction coefficient upper limit, then the preset dynamic correction coefficient upper limit will be used as the final correction coefficient after the amplitude is limited.

[0157] If the final correction coefficient is less than or equal to the preset lower limit of the dynamic correction coefficient, then the preset lower limit of the dynamic correction coefficient will be used as the final correction coefficient after the amplitude is limited.

[0158] If the final correction coefficient is greater than the preset lower limit of the dynamic correction coefficient but less than the preset upper limit of the dynamic correction coefficient, then the final correction coefficient will be directly used as the final correction coefficient after the amplitude is limited.

[0159] The preset upper limit of the dynamic correction coefficient is set to 1.5.

[0160] The preset lower limit of the dynamic correction coefficient is set to 0.5.

[0161] These two boundary values ​​are determined based on the safety envelope of the ship's tank test data. The upper limit prevents the feedforward command from being too large due to overcorrection, which could cause the main engine to overload. The lower limit prevents the control logic from reversing due to the correction coefficient being too small or even negative. When the coefficient of the correction calculated by the correction unit is greater than or equal to 1.5, the limiting unit directly forces the output to 1.5. When it is less than or equal to 0.5, it forces the output to 0.5. This direct clamping logic is simple and reliable. Once the parameter touches the boundary, the current correction amount will be automatically ignored, keeping the parameter running within the safety boundary. This ensures that the entire load disturbance observation model always works within the physically realizable range, avoiding system collapse caused by the divergence of model parameters.

[0162] By using the limiting unit to constrain the upper and lower limits of the final correction coefficient, the model parameters are strictly limited to a physically reasonable range. This safety barrier ensures that the load disturbance observation model always operates within the safe threshold under various operating conditions, preventing parameter runaway due to algorithm abnormalities or extreme external interference. It fundamentally avoids the risk of system instability caused by parameter out-of-bounds and ensures the continuous safe operation of the propulsion system.

[0163] The alarm unit is used to calculate the rate of change of the parameter of the final correction coefficient after limiting over time;

[0164] Compare the parameter change rate with the preset mutation threshold;

[0165] When the rate of change of parameters is detected to be greater than the preset mutation threshold, the system is determined to have an abnormal fault, and the parameters of the current load disturbance observation model are locked, while a fault alarm signal is output.

[0166] The preset mutation threshold is set to 0.8 MPa.

[0167] Within each control cycle, the difference between the currently acquired final correction coefficient after limiting and the coefficient value stored in the previous control cycle is calculated to obtain the coefficient change during that time period. Then, the coefficient change is divided by the set sampling cycle length to calculate the parameter change rate of the final correction coefficient over time.

[0168] When the rate of change of parameters exceeds this abrupt change threshold, the system is judged to have an abnormal fault such as sensor failure, communication packet loss, or hydraulic valve jamming. The current load disturbance observation model parameters are immediately locked, preventing them from receiving any updates. At the same time, a red warning window pops up on the ship's bridge display screen, and a fault code is sent to the central monitoring system. After the system enters the safe mode, the control strategy automatically degenerates into a conservative mode that relies solely on feedback control, and no longer performs feedforward compensation. The system will only return to the normal feedforward-feedback hybrid control mode after maintenance personnel manually confirm that the fault has been eliminated and perform a reset operation.

[0169] By monitoring the parameter change rate with the alarm unit and comparing it with the mutation threshold, real-time diagnosis and active defense against abnormal system faults are achieved. Once an abnormal mutation in the parameter is detected, the model parameter is immediately locked and an alarm signal is output, cutting off the propagation path of the erroneous parameter at the first time. This active protection mechanism can prevent the spread of faults, providing a high level of safety for ship navigation and greatly improving the intelligence level and reliability of the system.

[0170] This invention effectively solves the problem that load disturbance observation models struggle to accurately capture dynamic characteristic differences caused by changes in wake fraction, thrust reduction coefficient, and seawater density. By introducing a closed-loop calibration mechanism and online correction algorithm, it can update dynamic correction coefficients in real time based on the final torque residual signal, eliminating feedforward command deviations and improving system control accuracy. It can automatically adjust model parameters based on the residual signal between actual hydraulic pressure and theoretical pressure, compensating for parameter drift caused by environmental changes or long-term operation, ensuring consistently stable control performance. By dynamically adjusting the step size through sensitivity analysis based on gradient rate of change, it avoids oscillations or slow convergence during the correction process, optimizing parameter update efficiency. Combined with the setting of limiting and alarm units, it can promptly identify and lock abnormal parameter mutations, greatly enhancing the system's safety and reliability.

[0171] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code. The storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read Only Memory (EPROM), Programmable Red-Only Memory (PROM), Read-Only Memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0172] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A real-time control and monitoring system for a ship's controllable pitch propeller, characterized in that, It includes a construction module, an adjustment module, a compensation module, and a correction module; The construction module is used to construct a load disturbance observation model, calculate load disturbance prediction values ​​using the load disturbance observation model, and convert the load disturbance prediction values ​​into feedforward instructions; The adjustment module is used to adjust the pitch angle of the ship's controllable pitch propeller according to the feedforward command; The compensation module is used to calculate the difference between the current hydraulic pressure value and the theoretical hydraulic pressure value of the ship's controllable pitch propeller hydraulic actuator after adjusting the pitch angle, and obtain the final torque residual signal. The correction module is used to establish a closed-loop calibration mechanism. It determines whether the correction process is triggered based on the final moment residual signal. When the correction process is triggered, the load disturbance observation model is corrected online, the dynamic correction coefficients in the load disturbance observation model are updated, the final correction parameters are obtained, and the correction parameters are fed back to the load disturbance observation model. The construction module includes an acquisition unit, a monitoring unit, and a construction unit; The acquisition unit is used to acquire real-time rotational speed, real-time torque, and current speed data of the ship's main engine through different sensors. The different sensors include a speed sensor, a torque sensor, and a tachometer; The monitoring unit is used to take the real-time speed and real-time torque as input parameters and calculate the current actual propulsion power of the ship's main engine using a power calculation formula. The construction unit is used to construct a load disturbance observation model, obtain the pitch angle setting value of the ship's controllable pitch propeller, and obtain the theoretical power of the spectrum from the preset load characteristic spectrum based on the pitch angle setting value and the current speed data. The mathematical formula for the load disturbance observation model is: ； in, This indicates the predicted load disturbance value. This indicates the actual propulsion power. This indicates the pitch angle setting value. This indicates the current speed data. Indicates the theoretical power of the spectrum. Indicates the dynamic correction factor; The calculation logic for the dynamic correction coefficient includes: Based on a pre-set ship parameter database, read the wake fraction coefficient, thrust reduction coefficient, and seawater density correction coefficient corresponding to the current speed data; The dynamic correction coefficient is obtained by weighting and fusing the wake fraction coefficient, thrust deduction coefficient, and seawater density correction coefficient. The predicted load disturbance value is mapped to a hydraulic flow demand command through a preset flow mapping table, and the hydraulic flow demand command is used as a feedforward command.

2. The real-time control and monitoring system for ship controllable pitch propellers as described in claim 1, characterized in that, The adjustment module includes a parsing unit and a control unit; The analysis unit is used to receive the feedforward command, extract data from the feedforward command, obtain the flow rate value in the feedforward command, use the flow rate value as the instantaneous target flow rate of the hydraulic actuator of the ship, and convert the instantaneous target flow rate into the target valve core position of the hydraulic valve of the hydraulic actuator according to the preset valve core curve. The control unit is used to obtain the real-time valve core position of the hydraulic valve, compare the target valve core position with the real-time valve core position to obtain the position error, calculate the control current signal required by the hydraulic valve through a closed-loop control algorithm based on the position error, adjust the valve core opening of the hydraulic valve through the control current signal, and drive the hydraulic actuator to adjust the pitch angle of the ship's controllable pitch propeller.

3. The real-time control and monitoring system for ship controllable pitch propellers as described in claim 2, characterized in that, The compensation module includes a pressure detection unit and a processing unit; The pressure detection unit is used to collect the current hydraulic pressure value of the hydraulic actuator in real time through a high-precision pressure sensor installed in the ship's hydraulic circuit after the pitch angle adjustment is completed. The processing unit is used to calculate the theoretical driving torque based on the pitch angle setting value and the real-time rotation speed, and convert the theoretical driving torque into a theoretical hydraulic pressure value; The current hydraulic pressure value is subtracted from the theoretical hydraulic pressure value to obtain the initial torque residual signal. The initial torque residual signal is then low-pass filtered to obtain the final torque residual signal.

4. The real-time control and monitoring system for ship controllable pitch propellers as described in claim 3, characterized in that, The correction module includes a calibration unit, a correction unit, an adjustment unit, a limiting unit, and an alarm unit; The calibration unit is used to establish a closed-loop calibration mechanism and determine whether to trigger the correction process based on the final torque residual signal. The correction unit is used to perform online correction of the load disturbance observation model after triggering the correction process; The online correction includes gradient calculation and step size adjustment.

5. The real-time control and monitoring system for ship controllable pitch propellers as described in claim 4, characterized in that, The logic for establishing the closed-loop calibration mechanism includes: The final torque residual signal is used as a feedback input and input into the parameter update loop of the load disturbance observation model; In the parameter update loop, a threshold determination is performed on the final torque residual signal; When the final torque residual signal is greater than the preset error threshold, the load disturbance observation model is determined to be invalid, and the correction process is triggered. When the final torque residual signal is less than or equal to the preset error threshold, it is determined that the load disturbance observation model has not failed, the current parameters of the load disturbance observation model remain unchanged, and the correction process is not triggered.

6. The real-time control and monitoring system for ship controllable pitch propellers as described in claim 5, characterized in that, The logic for gradient calculation includes: A preset disturbance is applied to the dynamic correction coefficient within the load disturbance observation model. The difference between the final torque residual signal before and after the preset disturbance is applied is calculated. The ratio of the numerical difference to the preset disturbance is calculated, and the ratio is used as the gradient information of the final torque residual signal with respect to the dynamic correction coefficient. The logic for adjusting the step size includes: Read the numerical sign of the gradient information. If the gradient information is positive, determine that the step size direction is the direction in which the parameter decreases. If the gradient information is negative, then the step size direction is determined to be the direction in which the parameter increases; The gradient change rate of the gradient information over time is obtained, and the gradient change rate is compared with different sensitivity ranges to determine the sensitivity range of the gradient change rate. Obtain the sensitivity level corresponding to the sensitivity range; Based on the sensitivity level, obtain the corresponding step size adjustment coefficient from the preset step size mapping table; The sensitivity range includes a first range, a second range, and a third range; The sensitivity levels include a first level, a second level, and a third level; Among them, the first interval corresponds to the first level, the second interval corresponds to the second level, and the third interval corresponds to the third level; When the gradient change rate is less than or equal to the first threshold, the sensitivity range of the gradient change rate is determined to be the first range; When the gradient change rate is greater than a first threshold and less than a second threshold, the sensitivity range of the gradient change rate is determined to be the second range; When the gradient change rate is greater than or equal to the second threshold, the sensitivity range of the gradient change rate is determined to be the third range; The dynamic correction step size is calculated by multiplying the absolute value of the gradient information by the step size adjustment coefficient. The correction sign is determined based on the step direction; If the step size direction is the direction in which the parameter decreases, then the correction sign is negative; If the step size direction is the direction in which the parameter increases, then the correction sign is positive; The correction amount is obtained by multiplying the correction sign with the dynamic correction step size. The correction amount is added to the value of the dynamic correction coefficient to obtain the final correction coefficient.

7. The real-time control and monitoring system for ship controllable pitch propellers as described in claim 6, characterized in that, The adjustment unit is used to stop online correction of the load disturbance observation model when the absolute value of the final torque residual signal is less than a preset dead zone threshold.

8. The real-time control and monitoring system for ship controllable pitch propellers as described in claim 7, characterized in that, The limiting unit is used to constrain the final correction coefficient; The logic of the constraints includes: If the final correction coefficient is greater than or equal to the preset dynamic correction coefficient upper limit, then the preset dynamic correction coefficient upper limit is used as the final correction coefficient after amplitude limiting. If the final correction coefficient is less than or equal to the preset lower limit of the dynamic correction coefficient, then the preset lower limit of the dynamic correction coefficient is used as the final correction coefficient after the amplitude is limited. If the final correction coefficient is greater than the preset lower limit of the dynamic correction coefficient and less than the preset upper limit of the dynamic correction coefficient, then the final correction coefficient will be directly used as the final correction coefficient after the amplitude is limited.

9. The real-time control and monitoring system for ship controllable pitch propellers as described in claim 8, characterized in that, The alarm unit is used to calculate the rate of change of the parameter of the final correction coefficient after the limit changes over time; The rate of change of the parameter is compared with a preset mutation threshold; When the rate of change of parameters is detected to be greater than the preset mutation threshold, the system is determined to have an abnormal fault, and the parameters of the current load disturbance observation model are locked, while a fault alarm signal is output.

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