CN120817543B - Multi-parameter coordinated control method for the tilting and hoisting of underwater thrusters - Google Patents

Abstract

This invention discloses a multi-parameter collaborative control method for the tilting and hoisting of underwater thrusters, specifically in the field of underwater thruster hoisting. It addresses the problem of unstable tilting control under tidal disturbances by monitoring the dynamic state of the thruster tilting from two perspectives: curvature acceleration difference and tension phase drift. Adaptive step-size mapping is used to promptly compress the iteration interval in high-risk sections. Furthermore, a predictive correction loop synchronously corrects the angle increment and target tension before the winch action, achieving three-line linkage of angle adjustment, tension regulation, and environmental safety. The safety margin diagram is continuously refreshed under the dual-source drive of vibration and current velocity. Once a node approaches the warning domain, step-size rollback is triggered, preventing potential oscillations from escalating. A synchronization reliability coefficient is used throughout the entire process, evaluating the winch synchronization quality and assigning real-time weights to the step-size mapping, thus keeping the convergence path close to the actual equilibrium channel. This shortens the tilting time and stabilizes the tension fluctuation amplitude.

Description

Multi-parameter cooperative control method for controlling turning and hoisting of underwater propeller

Technical Field

The invention relates to the technical field of underwater propeller hoisting, in particular to a multi-parameter cooperative control method for controlling the turning-over hoisting of an underwater propeller.

Background

The turning and hoisting operation of the underwater propeller is completed under the environment of unstable tide and low visibility of water, the mechanical relationship among the winch, the sling and the propeller changes in real time along with the turning angle, and an operator must select the winch speed and the tension distribution according to the continuous calculation result so as to maintain the stable transition of the posture of the propeller. The operation is strong in angle-force synchronization, and any instruction delay or deviation can be directly converted into steel strand alternating load, so that the integrity of the sealing cover and the safety of the ship body are affected.

However, the existing control method generally adopts a fixed step length or an empirical step length to carry out step-by-step iteration, the superposition effect of the turning curvature mutation and the tension phase dislocation is not fully considered, the algorithm convergence path swings repeatedly on a high-order constraint surface, the frequent reverse direction of a winch is triggered easily, the tension peak value is coincided with the environmental disturbance instantaneously, the operation window is prolonged, and the cable breakage risk is increased.

In order to solve the above problems, a technical solution is now provided.

Disclosure of Invention

In order to overcome the defects in the prior art, the embodiment of the invention provides a multi-parameter cooperative control method for controlling the turning and hoisting of an underwater propeller, which aims to solve the problem of unstable turning control of the propeller under the disturbance of tide provided in the background art.

In order to achieve the above purpose, the present invention provides the following technical solutions:

S1, acquiring a turnover angle sequence and a sling tension sequence, executing secondary difference calculation on instantaneous curvature, and refining time intervals of a high curvature section according to a bipartite principle to generate an iteration step length table and writing the iteration step length table into a control unit;

s2, the control unit reads the iteration step list and the real-time tension value, calculates the next turning angle increment and the target tension value by adopting a least square prediction method, and sends a winding speed instruction;

S3, during the process that the winch executes a winch speed instruction, firstly obtaining a curvature acceleration difference value according to an angular speed curve and time differentiation of the angular speed curve, then calculating tension phase drift amounts of a front sling and a rear sling according to cross spectrum analysis, inputting the two tension phase drift amounts into a preset segmentation mapping table to output a synchronization reliability coefficient, and if the synchronization reliability coefficient is lower than a threshold value, shortening the current iteration step length and returning to S2 to refresh the winch speed instruction;

S4, the control unit continuously compares the flow rate monitoring data with the vibration frequency spectrum of the propeller to construct a safety margin map, and if a warning area appears in the safety margin map, the iteration step length is shortened as well and returns to S2 to carry out prediction correction;

And S5, when the synchronous reliability coefficient is stable and the safety margin graph keeps a positive value in the continuous cycle, the control unit sends a synchronous lifting instruction to finish turning over.

In a preferred embodiment, step S1 comprises the following:

The method comprises the steps of collecting overturning angle and tension data at fixed initial time intervals by using a sensor, calculating instantaneous curvature by a second-order difference method, identifying a high curvature section according to a curvature threshold value, halving the time intervals of the high curvature section to increase data collection frequency, generating an iteration step list for recording the time intervals of each section, and transmitting the iteration step list, an overturning angle sequence and a tension sequence to a control unit.

In a preferred embodiment, step S2 comprises the following:

the control unit extracts a step value of a current time section from the iteration step list as a current time step, calculates a turnover angle increment and a target tension value of the propeller at the next moment by adopting a least square prediction method based on a historical turnover angle sequence and a historical tension sequence, calculates a hoisting speed according to the turnover angle increment and the target tension value by utilizing a mechanical model, and sends the hoisting speed as a command to the hoist to adjust the winding and unwinding speed of the sling.

In a preferred embodiment, step S3 comprises the following:

during the process that the winch executes a winch speed instruction, the control unit monitors the turnover angle and the tension data in real time, calculates the angular speed and the angular acceleration by differentiating the turnover angle sequence, and compares the angular speed and the angular acceleration with the reference angular acceleration to obtain a curvature acceleration difference value.

In a preferred embodiment, step S3 further comprises the following:

and inputting the curvature acceleration difference value and the tension phase drift amount into a preset segmentation mapping table to generate a synchronous reliable coefficient.

In a preferred embodiment, step S3 further comprises the following:

When the synchronization reliability coefficient is lower than a preset threshold, the control unit shortens the iteration step and returns to the step S2 to recalculate the winding speed instruction.

In a preferred embodiment, step S4 comprises the following:

The control unit collects flow velocity monitoring data in the hoisting area in real time through the water flow sensor, performs frequency domain analysis to generate a vibration spectrum after collecting vibration signals on the propeller through the vibration sensor, utilizes the flow velocity monitoring data and the vibration spectrum to construct a safety margin map, shortens the current iteration step length and triggers the step S2 to regenerate a new hoisting speed instruction when the safety margin value is lower than a preset warning threshold value.

In a preferred embodiment, step S4 further comprises the following:

the safety margin graph is determined by calculating the product of the flow rate term ratio and the vibration term by taking time as the horizontal axis and taking a safety margin value as the vertical axis.

In a preferred embodiment, step S5 comprises the following:

The control unit continuously monitors the generated synchronization reliability coefficient and the safety margin map, judges that the synchronization reliability coefficient remains stable in a predetermined continuous period and the safety margin map remains positive in the predetermined continuous period.

In a preferred embodiment, step S5 further comprises the following:

When the synchronous reliability coefficient remains stable and the safety margin map maintains positive conditions are satisfied, the control unit issues a synchronous lifting command to complete the flipping operation, and then archives the data storage.

The multi-parameter cooperative control method for controlling the turning and hoisting of the underwater propeller has the technical effects and advantages that:

According to the invention, the turning-over dynamic state is monitored through the curvature acceleration difference value and the tension phase drift amount in a double-view mode, the iteration interval of the high-risk section is compressed in time by means of self-adaptive step mapping, and then the angle increment and the target tension are synchronously corrected before the hoisting action by utilizing a prediction correction loop, so that three-wire linkage of angle adjustment, tension adjustment and environmental safety is realized. The safety margin graph is continuously refreshed under the driving of the vibration and flow rate double information sources, and once the node approaches the warning domain, the step length rollback is triggered, so that potential oscillation is blocked in the sprouting stage. The synchronization reliability coefficient runs through the whole process, so that not only is the winch synchronization quality evaluated, but also the step length mapping is weighted in real time, and the convergence path is kept close to the real balance channel. The global cooperative logic eliminates reverse instruction accumulation and metal fatigue concentration, shortens turning time, stabilizes tension fluctuation amplitude, reserves high-resolution working condition files in the whole process, and provides reliable priori boundary and decision support for subsequent hoisting operation.

Drawings

Fig. 1 is a schematic flow chart of a multi-parameter cooperative control method for controlling turning and hoisting of an underwater propeller.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Embodiment 1 fig. 1 shows a multi-parameter cooperative control method for controlling turning and hoisting of an underwater propeller, which comprises the following steps:

S1, acquiring a turnover angle sequence and a sling tension sequence, executing secondary difference calculation on instantaneous curvature, and refining time intervals of a high curvature section according to a bipartite principle to generate an iteration step list, and writing the iteration step list into a control unit.

S2, the control unit reads the iteration step list and the real-time tension value, calculates the next turning angle increment and the target tension value by adopting a least square prediction method, and sends a winding speed instruction.

And S3, during the process that the winch executes the winch speed instruction, firstly obtaining a curvature acceleration difference value according to an angular speed curve and time differentiation of the angular speed curve, then calculating tension phase drift amounts of the front sling and the rear sling according to cross spectrum analysis, inputting the two tension phase drift amounts into a preset segmentation mapping table to output a synchronization reliability coefficient, and if the synchronization reliability coefficient is lower than a threshold value, shortening the current iteration step length and returning to S2 to refresh the winch speed instruction.

And S4, the control unit continuously compares the flow rate monitoring data with the vibration frequency spectrum of the propeller to construct a safety margin map, and if a warning area appears in the safety margin map, the iteration step length is shortened as well and the control unit returns to S2 to carry out prediction correction.

And S5, when the synchronous reliability coefficient is stable and the safety margin graph keeps a positive value in the continuous cycle, the control unit sends a synchronous lifting instruction to finish turning over.

The turning-over and hoisting operation of the underwater propeller is a high-difficulty task executed in a complex underwater environment, and the adverse conditions of unstable tide, low water visibility and the like need to be dealt with. In the hoisting process, the mechanical relationship among the winch, the sling and the propeller is dynamically adjusted along with the real-time change of the overturning angle, and an operator must determine the winch speed and the tension distribution through continuous calculation so as to ensure the stable transition of the posture of the propeller. The angle-force synchronization is a core requirement of the operation, and if instruction delay or deviation occurs, the steel strand can bear alternating load, thereby threatening the integrity of the sealing cover and the safety of the ship body. The traditional method is controlled by adopting a fixed step length or an empirical step length, and the problems of unstable algorithm convergence, frequent reversing of a winch and the like are easily caused because the superposition effect of the turning curvature mutation and the tension phase dislocation cannot be fully considered, so that the operation time is prolonged and the risk of breakage is increased.

The invention provides a multi-parameter cooperative control method for controlling turning and hoisting of an underwater propeller, which is used for realizing cooperative optimization of angle adjustment, tension adjustment and environmental safety by collecting turning angle and sling tension data in real time and combining with self-adaptive step adjustment and prediction correction technology. Step S1 is used as a starting point of the whole flow and is responsible for generating an iteration step list, providing an accurate time reference for the subsequent steps, and ensuring that a control instruction can adapt to the dynamic change of the turning process.

Step S1 includes the following:

S1-1, data acquisition:

Firstly, the overturning angle sequence of the propeller and the tension sequence of the sling are acquired in real time through an angle sensor arranged on the propeller and a tension sensor arranged on the sling. The overturning angle sequence of the propeller is used for reflecting the posture change of the propeller in the hoisting process, and the tension sequence of the sling is used for reflecting the stress state of the sling. During acquisition, data is recorded at fixed initial time intervals, such as every 0.1 seconds, to form discrete flip angle sequence data sets and tension sequence data sets. These datasets provide raw input for subsequent instantaneous curvature calculations and high curvature segment identification.

S1-2, calculating instantaneous curvature:

In order to quantify the rate of change of the flip angle sequence, a quadratic difference method is used to calculate the instantaneous curvature. The instantaneous curvature reflects the acceleration of the change of the turning angle and is used for identifying the key section of dynamic change in the turning process of the propeller. The specific calculation process is as follows:

For each time point in the overturning angle sequence, taking the angle value of the time point, subtracting the angle value of the previous time point to obtain a first difference value, taking the angle value of the next time point, subtracting the angle value of the time point to obtain a second difference value, and dividing the difference between the first difference value and the second difference value by the square of the initial time interval to obtain the instantaneous curvature value of the time point. This approach generates an instantaneous curvature sequence by numerically approximating the second order rate of change of the angle change.

The secondary difference method can effectively capture the acceleration change trend of the turnover angle sequence, and compared with the single difference method, the method can reflect the intensity in the dynamic process. The calculation of the instantaneous curvature sequence provides a quantization basis for the identification of the subsequent high-curvature section, and ensures that the control system can accurately judge the dynamic characteristics of the turning of the propeller.

S1-3, high curvature section identification and step length refinement:

based on the instantaneous curvature sequence, a curvature threshold, for example 0.05 radians per second squared, is set for distinguishing between high curvature sections and low curvature sections. For each time point in the instantaneous curvature sequence, if the instantaneous curvature value of the time point exceeds the curvature threshold value, judging that the time point belongs to a high curvature section and the turnover angle is changed severely, and if the instantaneous curvature value does not exceed the curvature threshold value, judging that the time point belongs to a low curvature section and the turnover angle is changed smoothly. For the high curvature section, the current time interval is halved, e.g., adjusted from 0.1 seconds to 0.05 seconds, to increase the frequency of data acquisition and control, and for the low curvature section, the initial time interval is kept unchanged.

The high curvature section and the low curvature section are distinguished through the curvature threshold value, and the time resolution can be adjusted according to the actual dynamic characteristics of the turning process of the propeller. The step length refinement of the high curvature section improves the density of data acquisition and the control precision, ensures that the data can be responded in time in the stage of severe change of the turning angle, reduces unnecessary calculation burden if the low curvature section keeps a larger step length, and improves the overall processing efficiency.

S1-4, generating an iteration step size table:

And generating an iteration step list according to the high curvature section identification and step refinement result, and recording the time step of each time section. The iterative step size table is presented in the form of a pair of time segments and corresponding step sizes, for example, the step size of one time segment is 0.1 seconds, and the step size of the other time segment is 0.05 seconds. Traversing the instantaneous curvature sequence, associating the high curvature or low curvature attribute of each time point with the corresponding time step in time sequence, and finishing the high curvature or low curvature attribute and the time step into a continuous time-step pair list to form a complete iteration step list.

The iteration step list realizes dynamic allocation of time resolution, and clearly records the control requirement of each time zone in the turning process of the propeller.

S1-5, a data writing control unit:

And transmitting the generated iteration step list, the turnover angle sequence and the tension sequence to a control unit. The control unit determines the calculation frequency of each time section according to the iteration step list, and predicts the turning state of the propeller and generates a control instruction by using the turning angle sequence and the tension sequence. The transmission process ensures that the time-step pairs in the iterative step list, the angle values in the flip angle sequence and the tension values in the tension sequence are completely transmitted in time sequence to support the real-time processing of the control unit.

The iteration step list, the turnover angle sequence and the tension sequence are input into the control unit together, so that comprehensive information required by the turnover control of the propeller is provided. The iteration step list sets a dynamic time reference for the control unit, and the overturning angle sequence and the tension sequence provide real-time state data, so that the control unit can dynamically adjust the instruction according to reality, and the safety and the efficiency of hoisting operation are improved.

Step S1, an iteration step list is generated by acquiring a turnover angle sequence and a sling tension sequence and based on the self-adaptive adjustment of the instantaneous curvature, and a dynamic time reference is provided for subsequent control. However, the step adjustment is not enough to cope with the complex dynamic relationship between the turnover angle and the tension in the turnover process and the influence of environmental factors such as tide disturbance. Step S2 is used as a core link of a control flow, and accurate winding speed instructions are generated by utilizing real-time data and a prediction model so as to ensure stable transition of the posture of the propeller and stable sling tension.

The processing technology logic of the step S2 aims at precisely adjusting the turning process of the propeller through the control unit, generating a winding speed instruction by utilizing input parameters, and ensuring cooperative control of the turning angle and the sling tension. The following is a detailed procedure.

Step S2 includes the following:

s2-1, determining the current time step:

The control unit first extracts a step value corresponding to the current time segment from the iteration step table, called the current time step. The iterative step list is generated by the step S1, and the calculation step of each time section is recorded and used for guiding the updating frequency of the control instruction. The determination of the current time step directly affects the time resolution of the predictive model and the sending cadence of the winding speed command. By reading a preset step value, the control unit can adjust the calculated and controlled frequency according to the dynamic requirement of the turning process, so that the system can respond to the change of the posture of the propeller in time.

The preset value in the iteration step list is used for determining the current time step, the control rhythm can be flexibly adjusted according to different stages of the turning process, response delay or excessively frequent calculation caused by fixed step length is avoided, and therefore the adaptability and the efficiency of the control system are improved.

S2-2, predicting the turning angle increment and the target tension value at the next moment:

The control unit calculates the turning angle increment and the target tension value at the next moment by adopting a least square prediction method based on the historical turning angle sequence and the historical tension sequence. The historical turning angle sequence records the turning angle of the propeller at the past time point, and the historical tension sequence records the tension value of the sling at the past time point, both provided by the step S1. The turning angle increment represents the turning angle change quantity of the propeller at the next moment relative to the current moment, and the target tension value represents the ideal tension value which the sling should reach at the next moment, and the unit is newton. The calculation idea of the least squares prediction method is to find a mathematical model that can best describe the relationship between these data by analyzing the trend of the change in the historical flip angle sequence and the historical tension sequence. Specifically, the method calculates the predicted value at the next time by comparing the deviation between the predicted value and the historical data, adjusting the sum of squares of all the deviations to be minimum, and determining the characteristic coefficient of the model.

The least square prediction method is adopted, so that dynamic information in the historical overturning angle sequence and the historical tension sequence can be fully utilized, and the interaction between the overturning trend of the propeller and the tension change can be accurately captured. The method provides prospective prediction through trend analysis of historical data, ensures stable transition of the posture of the propeller and stable control of sling tension, and accordingly improves reliability and accuracy of a system.

S2-3, calculating the hoisting speed:

And the control unit calculates the required hoisting speed by using a mechanical model according to the predicted turning angle increment and the target tension value. The mechanical model comprehensively considers the geometric relationship among the mass of the propeller, the rigidity of the sling and the overturning process. The calculation process includes multiplying the predicted turning angle increment by the effective length of the sling to obtain the displacement of the sling to be regulated during turning of the propeller, and dividing the displacement by the current time step to obtain the basic hoisting speed. And then, according to the target tension value, the basic hoisting speed is adjusted by an experimentally calibrated correction factor so as to ensure that the tension of the sling can be maintained within a predicted target range. The adjustment considers the nonlinear relation between the tension and the speed, ensures that the control command can realize the change of the turnover angle and can meet the requirement of the stability of the tension.

The hoisting speed is calculated through a mechanical model, and the predicted turning angle increment and the target tension value can be converted into specific execution instructions. The method combines physical laws and experimental data, ensures that the calculation result meets the movement requirement of the propeller, and can maintain the dynamic balance of the sling tension so as to ensure the safety and control precision of the turning process.

S2-4, sending a winding speed instruction:

The control unit sends the calculated winding speed to the winding machine as a command for guiding the winding and unwinding speed adjustment of the sling, thereby realizing the control of the turning-over process of the propeller. The winding speed command is in meters per second, and directly drives the operation of the winding engine. The sending process of the instruction ensures real-time communication between the control unit and the executing mechanism, so that the system can timely adjust the posture of the propeller and the tension state of the sling according to the calculation result.

There is a close contextual relationship between step S2 and steps S1 and S3. The iteration step list, the historical overturning angle sequence and the historical tension sequence generated in the step S1 are directly used as input parameters of the step S2, and continuity and consistency of data sources are ensured. The winding speed command calculated in the step S2 is transmitted to the step S3 for synchronous evaluation during execution. And S3, calculating a synchronization reliability coefficient by analyzing the angular velocity curve and the tension phase drift amount. If the synchronization reliability coefficient is lower than the preset threshold, the current control effect is insufficient, and step S3 shortens the current time step and requires step S2 to recalculate the winding speed command. The feedback mechanism enables the step S2 to dynamically adjust the control instruction according to the actual execution condition, and ensures the instantaneity and stability of the turning-over process.

And S2, calculating the turning angle increment and the target tension value at the next moment by using an iteration step list and a real-time tension value and adopting a least square prediction method, and generating a winding speed instruction. However, due to factors such as tide disturbance, water damping, system response delay and the like, a hoisting speed instruction may deviate from expectations in an actual execution process, so that synchronism of a turnover angle and tension distribution is damaged, and stability of the posture of the propeller is further affected. Therefore, step S3 serves as a key link for real-time monitoring and feedback, and quantifies the synchronization effect by evaluating the curvature acceleration difference and the tension phase drift, and adjusts the iteration step when necessary to ensure the stability and safety of the turning process.

The processing technology logic of the step S3 aims at ensuring the synchronism and the stability of the turning process of the propeller by monitoring and evaluating the effect of the winch executing the winch speed command in real time. The control unit calculates key indexes and dynamically adjusts control parameters based on the data acquired in real time and preset rules so as to realize stable transition of the posture of the propeller and stable control of the sling tension. The following is a detailed procedure.

Step S3 includes the following:

s3-1, calculating a curvature acceleration difference value:

the control unit first calculates the instantaneous angular velocity and the angular acceleration using the sequence of flip angles. The sequence of flip angles records the flip angles of the propeller at different points in time. The instantaneous angular velocity is obtained by analyzing the change rate of the overturning angle sequence along with time, and represents the overturning speed of the propeller. The angular acceleration is obtained by calculating the change rate of the instantaneous angular velocity with time, and the angular acceleration represents the magnitude of the turning acceleration of the propeller. Next, a reference angular acceleration is introduced, which is derived from the next flip angle increment estimated based on the least squares prediction method in step S2, reflecting the angular acceleration that the propeller should reach in an ideal state. The curvature acceleration difference is obtained by subtracting the actually calculated angular acceleration from the reference angular acceleration. The curvature acceleration difference value represents the deviation between the actual execution effect and the prediction model and is used for evaluating the synchronicity of the turning process of the propeller.

Calculating the curvature acceleration difference value can quantify the deviation degree of the actual motion state and the expected state in the turning process of the propeller. And by combining the real-time collected overturning angle sequence and the predicted generated reference angular acceleration, the monitoring result is ensured to have accuracy and foresight, a reliable basis is provided for subsequent synchronicity evaluation, and the response capability of the control system is effectively improved.

S3-2, calculating tension phase drift amount:

The control unit performs frequency domain analysis on the tension sequences of the front sling and the rear sling, and calculates tension phase drift amount. The tension sequences of the front sling and the rear sling record the tension values of the front sling and the rear sling at different time points respectively. Firstly, the control unit adopts a cross spectrum analysis method to convert the tension sequences of front and rear slings into frequency domain signals to generate a cross spectrum function. The cross-spectral function describes the correlation of the front and back sling tension signals at different frequencies. Then, by analyzing the cross-spectrum function, the tension phase drift amount is calculated, and the phase difference of the front and rear sling tension signals in the frequency domain is represented. The magnitude of the tension phase drift reflects the synchronization degree of the tension changes of the front sling and the rear sling, and the smaller the phase drift is, the higher the synchronization is, and otherwise, the synchronization deviation is indicated.

The cross-spectrum analysis method is a signal processing technique for analyzing the correlation and phase relationship between two signals. The interaction of the two signals at different frequencies is revealed by calculating the cross-spectrum of the two signals, i.e. the conjugate product of the fourier transforms of the two signals. The cross spectrum provides information on the amplitude and phase differences between the signals, and can identify the synchronicity, delay or phase drift of the signals. The method is widely applied to the fields of vibration analysis, acoustics, biomedicine and the like, and helps to evaluate the dynamic characteristics of the system or detect abnormal states.

And the synchronization of the tension changes of the front sling and the rear sling is evaluated by calculating the tension phase drift through frequency domain analysis, so that the limitation of only relying on time domain analysis is overcome. The dynamic characteristics of tension change can be captured, and comprehensive evaluation of synchronism is ensured, so that the accuracy and stability of tension control in the turning process of the propeller are improved.

S3-3, generating a synchronization reliability coefficient:

The control unit inputs the curvature acceleration difference value and the tension phase drift amount into a preset segmentation mapping table to generate a synchronization reliability coefficient. The synchronization reliability coefficient is a dimensionless value ranging from 0 to 1, and the closer the value is to 1, the better the synchronization of the turning process of the propeller is. The segmentation mapping table divides a plurality of intervals according to the curvature acceleration difference value and the amplitude range of the tension phase drift amount, and distributes corresponding synchronization reliability coefficients for each interval. For example, when the curvature acceleration difference value and the tension phase drift amount are both in a preset ideal range, the synchronization reliability coefficient takes a value of 1, and when any parameter exceeds the ideal range, the synchronization reliability coefficient is reduced according to a preset proportion.

The segment mapping table is a preset tool used for converting the curvature acceleration difference value and the tension phase drift amount into synchronous reliability coefficients so as to evaluate the synchronous effect of the turning process. Specifically, this function is achieved by dividing the magnitudes of the curvature acceleration difference and the tension phase drift amount into a plurality of sections, and assigning a corresponding synchronization reliability coefficient value to each section. The establishment of the mapping relation is based on the calibration of experimental data and system characteristics so as to ensure the objectivity and consistency of the evaluation result. For example, when the curvature acceleration difference and the tension phase drift amount are both within the ideal ranges, the synchronization reliability coefficient is set to 1, indicating that the synchronization effect is optimal, whereas when the difference or the drift amount is gradually increased, the synchronization reliability coefficient is reduced proportionally, and the lowest can be 0, reflecting the decrease in the synchronicity. By adopting the sectional mapping mode, the process of synchronicity evaluation is simplified, the control unit can conveniently and rapidly and accurately judge the synchronicity state of the turning process, and the system operation is regulated in real time according to the result, so that the overall performance and reliability are improved.

And the generated synchronization reliability coefficient integrates the curvature acceleration difference value and the tension phase drift amount into a single quantization index, so that the synchronization effect in the turning process can be conveniently and rapidly judged. The sectional mapping table is adopted to ensure the objectivity and consistency of the evaluation process, so that the control unit can efficiently make decisions according to the synchronous reliability coefficient, thereby optimizing the control precision of the turning process of the propeller.

S3-4, judging and adjusting iteration step length:

The control unit compares the synchronization reliability coefficient with a preset synchronization reliability coefficient threshold, for example, the threshold is set to 0.8. If the synchronization reliability coefficient is larger than or equal to the threshold value, the execution effect of the current propeller turning-over process is good, the control unit keeps the current iteration step length unchanged, and the follow-up steps are continuously executed. The iteration step is provided by the iteration step table generated in step S1. If the synchronization reliability coefficient is smaller than the threshold value, which indicates insufficient synchronization, the control unit shortens the current iteration step, for example, halving the value thereof, and returns to step S2 to recalculate the flip angle increment, the target tension value, and the winding speed command.

By comparing the synchronization reliability coefficient with the threshold value, the real-time monitoring and dynamic adjustment of the synchronism of the turning-over process are realized. The feedback mechanism can quickly shorten the iteration step length and increase the updating frequency of the control instruction when the synchronism is reduced, so that the stable transition of the posture of the propeller and the stable control of the front sling tension and the back sling tension are ensured, and the adaptability and the reliability of the system are improved.

A close technical relationship is formed between step S3 and steps S2 and S4. And the winding speed command generated in the step S2 is monitored and evaluated in real time by the step S3 during execution, so that the synchronism of the turning-over process of the propeller is ensured. And step S3, generating a synchronous reliability coefficient by calculating a curvature acceleration difference value and a tension phase drift amount, adjusting an iteration step length when the synchronism is insufficient, returning to the step S2, and recalculating control parameters to form a dynamic feedback loop so as to ensure the real-time performance and the stability of the control system. Meanwhile, the execution result of the step S3 provides support for the step S4, the step S4 builds a safety margin map by comparing the flow speed monitoring data with the propeller vibration frequency spectrum, the safety of the turning process is further evaluated, the iteration step is shortened when necessary, and the step S2 is returned to carry out prediction correction.

Because the regulation and control which is simply dependent on the angle and the tension cannot comprehensively evaluate the real-time effect of environmental factors, especially potential safety hazards possibly caused by flow velocity change and propeller vibration superposition. Therefore, step S4 introduces flow velocity monitoring data and a vibration spectrum of the propeller, builds a safety margin map to quantify risks and trigger iterative step adjustment when necessary, so that closed loop connection is formed with prediction correction of step S2, and safety and stability of operation are ensured.

Step S4 includes the following:

s4-1, data acquisition:

The control unit firstly collects the water flow speed in the hoisting area in real time through the water flow sensor, and generates flow speed monitoring data. The flow speed monitoring data reflects dynamic changes of tide in the operation environment and is an important basis for evaluating the influence of the environment on the turning of the propeller. Meanwhile, a vibration sensor arranged on the propeller is used for collecting vibration signals of the propeller, and frequency domain analysis is carried out on the vibration signals to generate a vibration frequency spectrum. The vibration spectrum describes the vibration intensity of the propeller at different frequencies for quantifying the vibration characteristics of the propeller during turning over. The purpose of collecting flow rate monitoring data and vibration spectrum is to comprehensively monitor the environment and equipment state and provide real-time input for subsequent safety evaluation.

S4-2, constructing a safety margin diagram:

The control unit constructs a safety margin map using the flow rate monitoring data and the vibration spectrum. The safety margin graph is a graph with time as a horizontal axis and a safety margin value as a vertical axis, and the safety margin value is a dimensionless value for comprehensively evaluating the safety state of the current operation. The calculation of the safety margin value combines the dual effects of the flow rate and vibration, namely, firstly, calculating a flow rate item, and obtaining the allowance proportion of the flow rate by comparing real-time flow rate monitoring data with a preset safety flow rate threshold value, wherein the safety flow rate threshold value is the upper flow rate limit calibrated according to the working environment and the propeller tolerance. And secondly, calculating a vibration term, and obtaining the relative deviation of vibration by comparing the energy difference between the real-time vibration spectrum of the propeller and the reference vibration spectrum in a specific frequency range, wherein the reference vibration spectrum is a standard vibration level calibrated in an ideal state without disturbance. And finally, multiplying the flow velocity term and the vibration term to obtain a safety margin value. The closer the safety margin value is to 1, the safer the operation, and when the safety margin value is reduced, the flow rate or vibration approaches a dangerous level.

The calculation of the safety margin value is determined by multiplying the flow rate item and the vibration item, so that the method has full theoretical basis and practical significance, and the double risks of environmental disturbance and equipment dynamic response in the turning and hoisting operation of the underwater propeller are comprehensively considered. The threat degree of the flow disturbance to the hoisting operation is quantified by calculating the allowance proportion of the real-time flow monitoring data and the safe flow threshold, and when the flow rate is close to or exceeds the safe threshold, the flow rate item approaches to zero, thereby reflecting the aggravation of the environmental risk. The vibration term evaluates the dynamic stability of the propeller during turning by comparing the energy deviation of the propeller vibration spectrum with a reference vibration spectrum, and when the vibration energy significantly exceeds the reference, the vibration term is reduced, indicating that the device may be at risk of instability or fatigue. The two are multiplied to form a safety margin value which can effectively capture the combined risk of flow velocity and vibration interaction, for example, high flow velocity may amplify the negative effects of vibration, and abnormal vibration may trigger structural resonance at a specific flow velocity. The product form is based on the engineering principle of risk superposition, ensures that the safety margin value is rapidly reduced when any factor exceeds the limit, triggers control adjustment, and simultaneously keeps a higher value when both the safety margin value and the safety margin value are safe, and reflects the stability of operation. The reliability of the method is further verified through experimental calibration and mechanical analysis, so that the method becomes a scientific basis for evaluating the operation safety.

And a safety margin graph is constructed to quantify the influence of the flow velocity and vibration into a single safety index, so that the control unit can conveniently and rapidly judge the safety state of the operation. The comprehensive perception of the potential risk by the control unit can be ensured by considering the environmental factors and the equipment factors at the same time, so that reliable safety guarantee is provided for the turnover and hoisting operation of the propeller.

S4-3, identifying a warning area:

The control unit continuously monitors the safety margin value in the safety margin map and compares the safety margin value with a preset warning threshold value. The guard threshold is a pre-calibrated lower safety limit, e.g., 0.2, for defining guard zones in the safety margin map. When the safety margin value is below the alert threshold, it indicates that the current operating condition has entered an alert zone, meaning that the flow rate or vibration has approached a dangerous level, potentially posing a threat to the safety of the propeller turning over process.

By setting the warning threshold and identifying the warning region, the control unit can timely find potential safety hazards. The early warning mechanism ensures that the control unit can take measures before the risk is aggravated, thereby effectively preventing accidents in the turning-over process of the propeller and improving the safety and reliability of the operation.

S4-3, iterative step length adjustment:

And the control unit dynamically adjusts the iteration step length according to the monitoring result of the safety margin graph and forms a feedback closed loop with the step S2. If the safety margin value is greater than or equal to the warning threshold value, indicating that the operation state is safe, the control unit keeps the current iteration step length unchanged, and continues to execute the existing control flow. The iteration step is provided by the iteration step table generated in step S1. If the safety margin value is lower than the warning threshold value, the control unit shortens the current iteration step, for example halving the current iteration step, so as to improve the updating frequency of the control instruction and slow down the response of the turning-over action to the environmental disturbance. The adjusted iteration step is written into an iteration step table of the control unit, and the control unit re-executes the step S2 according to the updated iteration step table and the real-time tension value, namely, calculates the next turning angle increment and the target tension value by adopting a least square prediction method, and generates a new winding speed instruction.

The step S4 forms a close technical link with the steps S1, S2 and S5. The iteration step list generated in the step S1 provides an initial calculation step for the step S4, the step S4 adjusts the iteration step when the safety margin is monitored to be insufficient, the adjusted iteration step is transmitted to the step S2, and the recalculation of the control instruction is triggered to form a dynamic feedback closed loop of the environmental disturbance and the control instruction. Meanwhile, the step S4 provides a safety premise for the synchronous lifting instruction in the step S5 according to the monitoring result of the safety margin map, and the turning operation is ensured to be completed when the safety margin keeps a positive value.

The steps S1 to S4 are used for generating an iteration step list by collecting the overturning angle sequence and the sling tension sequence, and realizing dynamic control and safety monitoring of the overturning process by combining a least square prediction method, a synchronous reliability coefficient and a safety margin map. The steps ensure the coordination of the turning angle of the propeller and the tension of the sling by adjusting the iteration step length and the winding speed command in real time, and continuously evaluate the environmental disturbance and the equipment vibration. However, simple real-time adjustment and monitoring are not enough to ensure final stability and safety of the whole turning process, and especially in environments with unstable tide and low visibility of water, the turning operation can be safely completed only when specific conditions are met. Step S5 is used as the end point of the whole flow, is responsible for judging whether the turning process reaches a safe and stable state, and finishes turning when the conditions are met, and simultaneously files operation data to support subsequent optimization.

Step S5 includes the following:

s5-1, monitoring a synchronization reliability coefficient and a safety margin diagram:

The control unit monitors the synchronization reliability coefficient and the safety margin map in real time by continuously collecting and analyzing data so as to evaluate the synchronization and the safety of the turning process of the propeller. And in each cycle period, calculating the continuous variation amplitude of the synchronous reliable coefficient, and judging whether the continuous variation amplitude is always smaller than or equal to a preset fluctuation amplitude threshold value in preset continuous cycle times, so as to confirm the stability of the synchronous reliable coefficient. Meanwhile, the control unit checks whether the numerical value in the safety margin diagram is always positive in the same continuous cycle times, so that the safety state of the operation is verified. Only when the fluctuation range of the synchronous reliability coefficient meets the stability condition and the numerical value of the safety margin graph keeps a positive value, the control unit can confirm that the turning process of the propeller is in a safe and stable state, otherwise, the control unit continues to monitor or returns to the regulation of the preamble step.

Through the real-time monitoring of the synchronization reliability coefficient and the safety margin diagram, the control unit can comprehensively master the dynamic performance of the propeller in the turning process, and ensures that the synchronization and the safety meet the expected requirements in a complex environment.

S5-2, judging turning completion conditions:

The control unit simultaneously evaluates the stability of the synchronous reliability coefficient and the positive value state of the numerical value in the safety margin graph in each cycle period to determine whether the turning process of the propeller reaches the completion requirement. The judging process firstly checks the variation amplitude of the synchronous reliable coefficient in the preset continuous cycle times, calculates the difference between the maximum value and the minimum value, compares the difference with a preset fluctuation amplitude threshold value, and considers the synchronous reliable coefficient to be stable if the difference is smaller than or equal to the threshold value. And secondly, checking whether the numerical values in the safety margin graph are positive values in the same continuous cycle times, and ensuring that all the numerical values are larger than zero by comparing the numerical values of each cycle with the relative sizes of zero one by one. Only when the stability condition of the synchronous reliability coefficient and the positive value condition of the safety margin diagram are simultaneously met within the continuous preset cycle times, the control unit judges that the turning process of the propeller reaches a safe and stable state and enters the subsequent process. If any condition is not met, returning to the step S3 to adjust the synchronism of the overturning angle sequence and the sling tension sequence, or returning to the step S4 to correct the matching degree of the flow velocity monitoring data and the vibration frequency spectrum until the condition is met.

By adopting double-condition verification of the stability of the synchronous reliability coefficient and the positive value of the safety margin graph, the control unit can accurately judge the completion time of the turning process of the propeller, and ensure that the operation is executed when the synchronism and the safety meet the requirements. The judgment mechanism reduces the risk of misjudgment through multi-dimensional data confirmation, and improves the accuracy and safety of the turning and hoisting operation of the propeller.

S5-3, issuing a synchronous lifting instruction:

When the stability of the synchronous reliability coefficient and the positive value state of the safety margin diagram are simultaneously met within the preset continuous cycle times, the control unit generates and issues a synchronous lifting instruction to coordinate the action of the winch to finish the turning over and lifting operation of the propeller. And (3) determining specific instruction content by calculating the tension adjustment amount required by each sling in the next period and the winding and unwinding speed of the winch based on the next turning angle increment and the target tension value predicted in the step (S2) by the synchronous lifting instruction. The instructions comprise a winding speed instruction and a tension distribution parameter, wherein the winding speed instruction is calculated through the relation between the turning angle increment and the time, and the tension distribution parameter is determined according to the distribution proportion of the target tension value among all slings. The control unit sends the instructions to the winch to guide the winch to adjust the retraction speed of each sling, so that the propeller stably ascends and descends to a target position after turning over, and the coordination and stability of the whole process are ensured.

By generating and issuing the synchronous lifting instruction, the control unit realizes accurate control of the winch and ensures that the propeller stably lifts to the target position after turning over. The instruction generation and execution mechanism ensures the synchronism and the stability of actions through pre-calculation and real-time coordination, and improves the execution efficiency and the safety of the turning and hoisting operation of the propeller.

S5-4, data archiving:

After the turning process of the propeller is completed, the control unit stores relevant data into the storage unit so as to support subsequent analysis and optimization. The stored data includes a sequence of flip angles, a sequence of sling tensions, and an iterative step size table. The overturning angle sequence records the angle change of the propeller at each time point in the overturning process, the angle change is generated by arranging the calculation results of the steps S2 and S3 by taking radian as a unit, the tension change of the sling at each time point before and after the sling tension sequence records is formed by summarizing the monitoring data of the step S3, and the iteration step length table records the iteration step length of each time section and is derived from the adjustment process of the steps S3 and S4. The control unit organizes the data in a time stamp alignment mode, ensures that the corresponding relation of each group of data is clear and traceable, and forms a high-resolution working condition file after being stored in the storage unit for reference and performance evaluation of subsequent hoisting operation.

Step S5 directly utilizes the synchronous reliability coefficient provided by step S3 and the safety margin value provided by step S4, and determines the turning over completion time through judging the stability and the positive value, so as to ensure that the requirements of synchronism and safety are met. Meanwhile, the synchronous lifting instruction generated in the step S5 depends on the turnover angle increment predicted in the step S2 and the target tension value, and the archived data provides a reference for the initial condition optimization in the step S1. The technical process of front-back connection ensures the stability, safety and continuity of the turning and hoisting operation of the propeller through data transmission and verification, and meets the high standard requirement of the operation in a complex environment.

The above formulas are all formulas with dimensions removed and numerical values calculated, the formulas are formulas with a large amount of data collected for software simulation to obtain the latest real situation, and preset parameters in the formulas are set by those skilled in the art according to the actual situation.

It should be noted that the system of the present invention can be deployed on the device itself to implement embedded applications, and also can run on a PC terminal or other terminals with user interfaces, so as to satisfy various hardware environments and use requirements.

While certain exemplary embodiments of the present invention have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that modifications may be made to the described embodiments in various different ways without departing from the spirit and scope of the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive of the scope of the invention, which is defined by the appended claims.

It is noted that relational terms such as first and second, and the like, if any, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (5)

1. The multi-parameter cooperative control method for controlling the turning and hoisting of the underwater propeller is characterized by comprising the following steps:

S1, acquiring a turnover angle sequence and a sling tension sequence, executing secondary difference calculation on instantaneous curvature, and refining time intervals of a high curvature section according to a bipartite principle to generate an iteration step length table and writing the iteration step length table into a control unit;

Step S1 includes the following:

The method comprises the steps of collecting turnover angle and tension data at fixed initial time intervals by using a sensor, calculating instantaneous curvature by a second-order difference method, identifying a high curvature section according to a curvature threshold value, halving the time intervals of the high curvature section to increase data collection frequency, generating an iteration step list for recording the time intervals of each section, and transmitting the iteration step list, a turnover angle sequence and a tension sequence to a control unit;

s2, the control unit reads the iteration step list and the real-time tension value, calculates the next turning angle increment and the target tension value by adopting a least square prediction method, and sends a winding speed instruction;

step S2 includes the following:

the control unit extracts a step value of a current time section from the iteration step list as a current time step, calculates a turnover angle increment and a target tension value of the propeller at the next moment by adopting a least square prediction method based on a historical turnover angle sequence and a historical tension sequence, calculates a hoisting speed according to the turnover angle increment and the target tension value by utilizing a mechanical model, and sends the hoisting speed as a command to the hoist to adjust the winding and unwinding speed of the sling;

S3, during the process that the winch executes a winch speed instruction, firstly obtaining a curvature acceleration difference value according to time differentiation of an angular speed curve and an angular speed curve, then calculating tension phase drift amounts of a front sling and a rear sling according to cross spectrum analysis, inputting the two tension phase drift amounts into a preset segmentation mapping table to output a synchronous reliability coefficient, and if the synchronous reliability coefficient is lower than a preset threshold value, shortening the current iteration step length and returning to S2 to refresh the winch speed instruction;

step S3 includes the following:

During the process that the winch executes a winch speed instruction, the control unit monitors the turnover angle and tension data in real time, calculates angular speed and angular acceleration by differentiating the turnover angle sequence, and compares the angular speed and the angular acceleration with reference angular acceleration to obtain a curvature acceleration difference value;

S4, the control unit continuously compares the flow rate monitoring data with the vibration frequency spectrum of the propeller to construct a safety margin map, and if a warning area appears in the safety margin map, the iteration step length is shortened as well and returns to S2 to carry out prediction correction;

And S5, when the synchronous reliability coefficient is stable and the safety margin graph keeps a positive value in the continuous cycle, the control unit sends a synchronous lifting instruction to finish turning over.

2. The multi-parameter cooperative control method for controlling turning and hoisting of an underwater propeller according to claim 1, wherein the step S4 comprises the following steps:

The control unit collects flow velocity monitoring data in the hoisting area in real time through the water flow sensor, performs frequency domain analysis to generate a vibration spectrum after collecting vibration signals on the propeller through the vibration sensor, utilizes the flow velocity monitoring data and the vibration spectrum to construct a safety margin map, shortens the current iteration step length and triggers the step S2 to regenerate a new hoisting speed instruction when the safety margin value is lower than a preset warning threshold value.

3. The multi-parameter cooperative control method for controlling turning and hoisting of an underwater propeller according to claim 2, wherein step S4 further comprises the following steps:

the safety margin graph is determined by calculating the product of the flow rate term ratio and the vibration term by taking time as the horizontal axis and taking a safety margin value as the vertical axis.

4. The multi-parameter cooperative control method for controlling turning and hoisting of an underwater propeller according to claim 3, wherein the step S5 comprises the following steps:

The control unit continuously monitors the generated synchronization reliability coefficient and the safety margin map, judges that the synchronization reliability coefficient remains stable in a predetermined continuous period and the safety margin map remains positive in the predetermined continuous period.

5. The multi-parameter cooperative control method for controlling turning and hoisting of an underwater propeller according to claim 4, wherein the step S5 further comprises the following steps:

When the synchronous reliability coefficient remains stable and the safety margin map maintains positive conditions are satisfied, the control unit issues a synchronous lifting command to complete the flipping operation, and then archives the data storage.