WO2018233025A1

WO2018233025A1 - Early warning method, apparatus, and device for parametric roll resonance of ocean-floating structures

Info

Publication number: WO2018233025A1
Application number: PCT/CN2017/099596
Authority: WO
Inventors: 马宁; 于立伟; 平川嘉昭; 荒井诚; 王德禹; 顾解忡
Original assignee: 上海交通大学; 国立大学法人横滨国立大学
Priority date: 2017-06-23
Filing date: 2017-08-30
Publication date: 2018-12-27
Also published as: CN109110073A; JP6928973B2; CN109110073B; JP2020524635A

Abstract

Provided are an early warning method, apparatus, and device for parametric roll resonance of an ocean-floating structure. The method comprises: acquiring motion signals of different degrees of freedom of an ocean-floating structure collected in real time; linearly superimposing time history data of different motion signals to obtain time history data of a combined signal; generating, according to the time history data of the combined signal, instantaneous frequency time history data of a time-varying instantaneous frequency of the combined signal; identifying discontinuities from the instantaneous frequency time history data, wherein the discontinuities are caused by a frequency doubling relationship between motion signals of at least two degrees of freedom when parametric roll resonance occurs; and performing a calculation according to the frequency discontinuities to obtain a time at which parametric roll resonance occurs so as to achieve early warning. The method can implement advance warning of parametric roll resonance by means of more efficient algorithms and fewer device costs, and can consume less energy to effectively prevent parametric roll resonance when an initial motion amplitude is low.

Description

Early warning method, device and device for parameter resonance motion of marine floating structure

Technical field

The invention relates to the field of marine and marine engineering, in particular to an early warning method, device, storage medium and device for detecting parametric resonance motion of a marine floating structure.

Background technique

Marine floating structures such as ships, offshore platforms and offshore floating fans, in addition to conventional wave-induced motions under wave excitation, can also undergo nonlinear parametric resonance motions such as: container ship and luxury cruise ship parameters roll Motion, SPAR platform and parametric motion of floating fans at sea. When the parametric resonance occurs, it will be accompanied by the drastic movement of the floating structure or even the instability and overturning, causing significant loss of personnel and property, such as the loss of the container ship under large parameters, the SPAR platform and the floating fan at sea. Large-scale parameters such as cable breakage under pitching motion. Therefore, it is urgent to take measures to avoid the occurrence of parametric resonance.

At present, the marine floating structure is equipped with active (active anti-rolling water tank, fin stabilizer, dynamic positioning system, etc.) and passive devices (passive anti-rolling tank, bilge keel, heave plate, etc.) for wave stimulation. Effective evasion of exercise. However, these devices have limited effect on parametric resonance motion avoidance that is more severe than conventional wave motion. According to the characteristics of the parametric resonance motion, when the parameter resonance condition is satisfied at the initial stage, the motion amplitude is small. Therefore, if an early warning can be made at the beginning of the parametric resonance, and the device is used to change the condition for achieving resonance, it is possible to efficiently avoid the parametric resonance motion by consuming a small amount of energy. It can be seen that the advance warning device of the marine floating structure is of great significance for its safety.

Chinese invention patent application "a method for predicting and controlling ship track tracking with active suppression of parameter roll" (publication number: CN104881040A) proposes that when the ship is subjected to parameter roll, the rudder is used to minimize the track tracking performance of the ship at the expense of the ship. Under the premise, the parameter roll is suppressed. In the invention, the rudder performs the yaw when a large parametric resonance motion occurs, which requires a large amount of energy and affects the track tracking performance of the ship. It can be seen that the advance warning of the parametric resonance motion is important for suppressing when the motion amplitude is small. The inventor of the Korean patent "Parametric roll preventing apparatus and method for vessel" (Announcement No.: KR100827396B1) proposes an early warning method and apparatus for ship parameter roll, and uses the rudder to perform parameter roll suppression. The wave monitoring device that needs to be used in the early warning device is not easy to obtain, and the application has certain limitations, which is obviously different from the parameter resonance early warning in the present invention using only the easily acquired motion signal. The inventor of the Danish patent "Prediction of resonant oscillation" (Publication No.: WO2010118752A1) proposes an algorithm and apparatus for performing parameter resonance prediction between two related oscillating signals, which perform two correlation oscillating signals in the time domain and the frequency domain. Transform processing, and then frequency discrimination in the frequency domain The two phases of the phase identification in the identification and time domain are used to predict the parameter resonance. However, the algorithm and the device only involve the warning of the parameter roll, and the design is not specifically designed for the timeliness of the warning, which is significantly different from the advance warning emphasized by the present invention, and the algorithm of the present invention adopts Hilbert- The yellow method directly obtains the time-frequency combined information, which is fundamentally different from the method of obtaining time domain and frequency domain information respectively.

Summary of the invention

In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide an early warning method, device, medium and device for the resonant motion of parameters of a marine floating structure, and to realize parameter resonance motion by using a more efficient algorithm and less device cost. The advance warning is expected to be able to efficiently avoid the parametric resonance motion when the amplitude of the initial motion of the parametric resonance is small and consumes a small amount of energy.

To achieve the above and other related objects, the present invention provides an early warning method for parameter resonance motion of a marine floating structure, comprising: acquiring motion signals of different degrees of freedom of the marine floating structure collected in real time; The time history data of the different motion signals are linearly superimposed to obtain time history data of the combined signal; the instantaneous frequency time history data of the instantaneous frequency of the combined signal is generated according to the time history data of the combined signal; A frequency mutation is identified in the frequency history data; wherein the frequency mutation is caused by a frequency doubling relationship between motion signals at least two degrees of freedom when the parameter resonance motion occurs; and the parameter resonance is calculated according to the frequency mutation The moment of the movement takes place for early warning.

In an embodiment of the invention, the instantaneous frequency of the instantaneous frequency of the combined signal is generated according to the time history data of the combined signal, and the historical data is implemented based on the incremental real-time Hilbert-Huang algorithm, including : selecting all modal functions that are locally symmetrical to the mean zero from the combined signal; performing a Hilbert transform on the filtered modal function to obtain the instantaneous frequency.

In an embodiment of the invention, the calculating the time at which the parameter resonance motion occurs according to the frequency mutation includes: establishing condition Γ1 and condition Γ ₂ :

Where f _MA (t) is the instantaneous frequency, t _h is the time of the Gibbs peak point, μ ₁ is the parameter, T _S2 is the natural period of the target motion signal, and the frequency falling amplitude α indicates the frequency relative to [0, t _h The amplitude of the average frequency f _Average (t _h ) in the interval, α _cr is the preset critical frequency falling amplitude;

Where Θ _PR is the rate of change threshold, above which the parameter resonance motion may occur, and below this threshold value is not the frequency change caused by the parameter resonance; according to the condition Γ1 and condition Γ ₂ , the parameter is calculated. The moment at which the resonance motion occurs is t _p = t _h + μ ₁ T _S2 .

In an embodiment of the invention, the change rate threshold Θ _{PR is} set to: a difference between a natural frequency of the target motion signal and a natural frequency of a motion signal that forms a multiplication relationship with the target motion signal, and a transition time And a ratio, wherein the transition time is a sum of a natural period of the target motion signal and a natural period of a motion signal that forms a multiplication relationship with the target motion signal.

In an embodiment of the invention, before the time when the parameter resonance motion is calculated according to the condition Γ1 and the condition Γ ₂ , the instantaneous frequency time history data is preprocessed to eliminate the data point caused by the numerical error; The pre-processed instantaneous frequency history data is substituted as the instantaneous frequency f _MA (t) into the condition Γ ₁ and the condition Γ ₂ for calculation.

In an embodiment of the invention, the pre-processing is implemented based on a moving average algorithm.

To achieve the above and other related objects, the present invention provides an early warning device for a parametric resonance motion of a marine floating structure, comprising: a signal acquisition module, configured to acquire different degrees of freedom of the marine floating structure collected in real time. a motion signal; a signal processing module, configured to linearly superimpose the time history data of the different motion signals to obtain time history data of the combined signal; and generate an instantaneous frequency of the combined signal according to the time history data of the combined signal with time Varying instantaneous frequency history data; identifying a frequency mutation from the instantaneous frequency history data; wherein the frequency mutation is a frequency doubling relationship between motion signals at least two degrees of freedom when the parametric resonance motion occurs The resonance early warning module is configured to calculate a time at which the parameter resonance motion occurs according to the frequency mutation to provide an early warning.

In an embodiment of the invention, the signal processing module generates the instantaneous frequency time history data according to the time history data of the combined signal, which is implemented based on an incremental real-time Hilbert-Huang algorithm, including: All the modal functions that are locally symmetrical to the mean zero are selected in the combined signal; the filtered modal function is subjected to a Hilbert transform to obtain the instantaneous frequency.

In an embodiment of the invention, the resonance early warning module calculates the time at which the parameter resonance motion occurs according to the frequency mutation calculation is achieved by: establishing condition Γ1 and condition Γ ₂ :

In an embodiment of the invention, the apparatus further includes: a data pre-processing module, configured to perform the instantaneous frequency history data before the time when the parameter resonance motion is calculated according to the condition Γ1 and the condition Γ ₂ Preprocessing to eliminate data points caused by numerical errors; the pre-processed instantaneous frequency history data is substituted as the instantaneous frequency f _MA (t) into the condition Γ ₁ and condition Γ ₂ for calculation.

To achieve the above and other related objects, the present invention provides a storage medium storing a computer program that, when executed by a processor, implements a resonant motion of a marine floating structure parameter as described above. Early warning method.

To achieve the above and other related objects, the present invention provides an electronic device comprising: a processor, and a memory; wherein the memory is for storing a computer program; the processor is configured to load and execute the computer program to enable The electronic device performs an early warning method for a resonant motion of a marine floating structure parameter as described above.

To achieve the above and other related objects, the present invention provides an early warning system for parametric resonance motion of a marine floating structure, comprising: an angular motion detecting device disposed on the marine floating structure for collecting the ocean in real time. Motion signals on different degrees of freedom of the floating structure; an electronic device as described above, communicatively coupled to the angular motion detecting device.

As described above, the method, device and device for predicting the resonance motion of the marine floating structure of the present invention select a more efficient algorithm and less device cost to realize the advance warning of the parameter resonance motion than the patent KR100827396B1; Compared with the patent WO2010118752A1, the IR-HHT algorithm is used to obtain the motion time-frequency information for the advance warning of the parametric resonance motion. In addition, the present invention is also specially designed for the timeliness of the early warning, and can perform the advance warning of the parametric resonance motion when the amplitude of the initial motion of the parametric resonance is small, so that the parametric resonance can be efficiently avoided by consuming a small amount of energy. motion.

DRAWINGS

FIG. 1 is a schematic diagram showing a scene of a parametric resonance motion of a marine floating structure according to an embodiment of the invention.

Figure 2 is a graph showing the time history data of the pitch motion signal S1 and the roll motion signal S2 in the model experiment of the present invention.

FIG. 3 is a schematic diagram showing an early warning hardware device for parameter resonance motion of a marine floating structure according to an embodiment of the invention.

FIG. 4 is a schematic diagram showing an early warning method for parameter resonance motion of a marine floating structure according to an embodiment of the invention.

FIG. 5 shows a flow chart of an incremental real-time Hilbert-Huang (IR-HHT) algorithm in accordance with an embodiment of the present invention.

6 is a diagram showing an instantaneous frequency curve f(t) and its moving average f _MA (t) and a rate of change -10f' _MA (t) in an embodiment of the present invention.

Fig. 7 is a graph showing the simulation results of the parameter advance warning of the parameters obtained in the model experiment of the present invention.

FIG. 8 is a schematic diagram of an early warning software device for parameter resonance motion of a marine floating structure according to an embodiment of the invention.

Detailed ways

The embodiments of the present invention are described below by way of specific examples, and those skilled in the art can readily understand other advantages and effects of the present invention from the disclosure of the present disclosure. The present invention may be embodied or applied in various other specific embodiments, and various modifications and changes can be made without departing from the spirit and scope of the invention. It should be noted that the features in the following embodiments and embodiments may be combined with each other without conflict.

It should be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present invention in a schematic manner, and only the components related to the present invention are shown in the drawings, rather than the number and shape of components in actual implementation. Dimensional drawing, the actual type of implementation of each component's type, number and proportion can be a random change, and its component layout can be more complicated.

The present invention provides an advanced warning algorithm and apparatus for parametric resonance motion of marine floating structures (eg, ships, offshore platforms, and offshore floating fans, etc.), using more efficient algorithms and less device cost to implement parameters The advance warning of the resonance motion is expected to be able to efficiently avoid the parametric resonance motion when the amplitude of the initial motion of the parametric resonance is small and consumes a small amount of energy.

As shown in Fig. 1, the marine floating structure 2 performs a six-degree-of-freedom oscillation motion under the excitation of the wave 1, including: x turbulence, y sway, z sway,

Roll, θ pitch, shake.

When the parametric resonance motion occurs, the ocean floating structure performs wave frequency motion in some degrees of freedom, and performs low frequency resonance motion in some degrees of freedom. There are frequency doubling relationships between two types of motions of different frequencies, such as: The frequency-doubling relationship between the pitch and the heave motion and the roll motion when the parameter is panned, and the multiplication relationship between the heave and the pitch motion during the steep tilt of the Spar platform.

The following will take the ship's parametric roll as an example to clarify the mechanism of the parametric resonance motion and its frequency doubling relationship.

The ship parameter roll is a self-excited vibration caused by the nonlinear periodic variation of the rolling recovery force in the longitudinal wave, which is simplified to the Matthew equation of the following form:

among them,

For the roll angle, ζ is the damping coefficient, ω ₀ and ω represent the roll natural frequency and the wave encounter frequency, ε is the roll recovery force amplitude, and εcosωt is the periodic change roll recovery force. When ζ and ε are small, there is an unstable boundary near ω=2ω ₀ , that is, the pitch frequency is twice the natural frequency of the roll, which is the frequency doubling relationship that is satisfied when the parametric resonance motion occurs.

Fig. 2 shows the time history curves of the pitch motion signal S1 (see 11) and the roll motion signal S2 (see 10) in the frequency multiplication relationship when the parameter resonance motion obtained in the model experiment occurs. As can be seen from Figure 2, between two dashed vertical lines, signal S2 completes a period of oscillatory motion, while signal S1 completes two periods of oscillatory motion, indicating the formation of parametric resonance conditions. At the same time, the amplitude of the signal S2 increases rapidly, resulting in a large and intense movement, which poses a great threat to the safety of marine floating structures.

It can also be seen from Fig. 2 that this multiplication relationship between S1 and S2 has also been formed when the amplitude of the signal S2 is still small. Therefore, the present invention recognizes such a frequency doubling relationship by a small amplitude of motion at the initial stage of resonance, thereby performing early warning of parameter resonance.

Referring to FIG. 3, the early warning device for the parametric resonance movement of the marine floating structure mainly includes: a motion detecting device and an electronic device electrically connected to the motion detecting device, wherein the motion detecting device is preferably a six-axis gyroscope 301 The electronic device is a device including a processor (CPU/MCU/SOC), a memory (ROM/RAM), an input/output interface (bus interface/communication interface), and a system bus, and is preferably a micro-master computer 302. In an actual marine application scenario, the motion detection device and the electronic device can be installed in the equipment container box of the ship (Fig. 4, reference numeral 4), and with an early warning monitor installed in the ship's cab (Fig. 1 of Fig. 3) ) Communication connection.

As shown in FIG. 4, in an implementation of the present invention, the marine floating structure is oscillated under the excitation of waves, and the six-axis gyroscope 301 collects two related motion signals S1 and S2 in which parameter resonance may occur in real time. The calendar is transferred to the mini-master computer 302. The micro-master computer 302 integrates a pre-warning algorithm for parametric resonance motion. The algorithm first linearly superimposes two signal time calendars to obtain a signal time calendar x(t)=S1+S2; then, based on the incremental real-time Hilbert The Incremental Real-time Hilbert-Huang Transform (IR-HHT) algorithm analyzes the signal time history x(t) to obtain the instantaneous frequency (Instantaneous Frequency, IF for short) containing two motion signals. Then, the algorithm analyzes the obtained instantaneous frequency and obtains the early warning result by identifying the frequency mutation caused by the parameter resonance. Finally, the early warning result is transmitted to the cab's early warning monitor through the wireless signal 7. When the warning signal indicates that the parameter resonance occurs, corresponding measures can be taken to avoid the parameter resonance motion.

The principle of the early warning method for the parametric resonance motion of the marine floating structure of the present invention will be described in detail below.

In the IR-HHT algorithm, it is assumed that any complex signal can be decomposed into a finite number of Intrinsic Mode Functions (IMFs) with certain physical meanings. In order to obtain the IMF, a screening process called Empirical Mode Decomposition (EMD) is used in this algorithm to gradually find a series of IMFs with different frequencies from high to low by means of repeated screening procedures. In order for the IMF to have a certain physical meaning, two conditions should be met:

1) The sum of the number of local maxima and minima on the curve must be equal to or equal to the number of zeros;

2) At any time, the envelope of the local maxima consisting of the envelope and the local minimum is taken to be close to zero.

The first condition guarantees that the IMF is narrowband and the second condition guarantees that the IMF has no zero offset. These two conditions ensure that the IMF can be locally symmetric to the mean zero, making it similar to a sinusoid-like, but its period and amplitude are different from the chord function and may change. For these IMFs like chord functions, using the Hilbert transform directly, a meaningful instantaneous frequency IF can be obtained.

The EMD process in the IR-HHT method is shown in Figure 5, specifically, for an original signal x(t):

Step 1. Initialize r ₀ (t)=x(t), i=1;

Step 2. Decompose the i-th IMF, including:

A. Initial: h ₀ (t) = r _i (t), k = 1;

B. Find all local maxima of h ₀ (t) and local minima h _k-1 (t), if there is no new extremum, skip to step D;

C. Using Hermite interpolation, the local maximum and minimum values are respectively connected into upper and lower envelopes;

D. Calculate the average of the upper and lower envelopes to obtain the mean envelope m _k-1 (t);

Eh _k (t)=h _k-1 (t)-m _k-1 (t);

F. Check whether h _k (t) meets the conditions of the IMF; if it meets, IMF _i (t)=h _k (t), continue with step 3; if not, return to step B and let k=k+1;

Step 3. Define r _i (t)=r _i-1 (t)-IMF _i (t);

Step 4. If r _i (t) still contains at least two maxima, proceed to step 2 and let i=i+1; otherwise, r _i (t) is the average trend component of x(t).

If the IMF cannot be decomposed again, it is considered to have completed the EMD screening process. The signal x(t) is equal to the superposition of the n IMFs with an average trend:

Thus, the signal x(t) is decomposed into n IMFs of frequency from high to low and a trend function, and the IMF of the signals S1 and S2 is Hilbert transformed to obtain the instantaneous frequency IF. Figure 6 is the instantaneous signal x(t) of the signals S1 and S2 in Figure 2. Time frequency IF curve f(t) (see 12). It can be seen from the curve that the instantaneous frequency IF is abruptly caused by the frequency doubling relationship when the parametric resonance motion occurs, and the frequency of the IF is decreased from the frequency of the signal S1 to the frequency of the signal S2 (the frequency of the signal S1 predominates before the frequency mutation, and the signal after the frequency mutation) The frequency of S2 is dominant). The present invention will predict the moment at which the parametric resonance occurs based on the mutation design advance warning algorithm of this instantaneous frequency IF.

First, the Moving Average method is introduced to preprocess the IF curve f(t) to eliminate the sharp point caused by the numerical error in the graph of Fig. 6. The instantaneous frequency f _MA (t) obtained by moving average (see 13) and its rate of change -10f' _MA (t) are plotted as shown in Fig. 6. Therefore, based on the instantaneous frequency f _MA (t) to design the advanced warning algorithm of the parametric resonance motion, the algorithm includes two conditions: the frequency variation condition Γ ₁ and the rate of change condition Γ ₂ .

The frequency variation condition Γ _{1 is} used to identify the frequency abrupt change when the parameter resonance occurs. According to the Gibbs phenomenon, the discontinuity in frequency is reflected in the instantaneous frequency as a hump (see 14), as shown in Figure 6. The frequency change condition is designed based on this peak point in the advance warning algorithm Γ ₁ :

Among them, the first line condition takes the maximum value of the instantaneous frequency as the possible Gibbs peak point, and t _h is the time of the peak point; the second line is used to determine the instantaneous frequency in the interval [0, μ ₁ T _S2 ] Whether it is in the falling phase, where μ ₁ is the parameter, preferably, it is set to 0.8 to 1; in the third row, the frequency decreasing amplitude α represents the average frequency f _Average (t _h ) in the frequency range [0, t _h ] The magnitude of the drop, the critical frequency drop amplitude α _cr is preferably set to around 0.5, which is also the ratio of the frequency of the signal S2 to the frequency of the signal S1 when the parametric resonance motion occurs. Thus, the formula establishes the frequency variation condition Γ ₁ by determining the magnitude of the frequency drop after the Gibbs peak point.

Since the sudden change in the instantaneous frequency may also occur in a slow sea state change, the rate of change condition Γ _{2 is} introduced as another criterion. First, it is necessary to set a rate of change threshold Θ _PR . If the threshold is exceeded, the parameter resonance motion may occur. Below the threshold, it is not the frequency change caused by the parameter resonance.

When the resonance parameters, combined signal x (t) is the instantaneous frequency will be _tran t fall transition time from a certain frequency F _S1 signal S1 to the signal S2 of the frequency f _S2. Thus, the rate of change threshold Θ _PR can be set:

Wherein, the periods of the signals S1 and S2 satisfy T _S1 =T _S2 /2; the transition time t _{tran is} set to the sum of one S1 period and one S2 period. Finally, set the rate of change condition Γ ₂ :

Among them, if the change rate threshold Θ _{PR is} set too small, the instantaneous change of the instantaneous frequency caused by the change of sea state will be erroneously predicted, and if it is too large, the parameter roll may not be predicted.

So far, the advance warning algorithm based on the IR-HHT method uses the frequency change condition Γ ₁ and the change rate condition Γ ₂ to predict the parameter roll, and the parameter roll occurs at t _p : t _p= t _h +μ ₁ T _S2 .

The parametric resonance motion advance warning algorithm and device of the present invention are installed in a model of a container ship to carry out the advance warning of the container ship's parameter roll, and the effect of the invention is verified by experiments, and the early warning result is shown in FIG. 7 .

Figure 7 shows the experimental results of four operating conditions. The results of each working condition include the time history of the roll angle 15 and the pitch angle 16 collected by the six-axis gyroscope in the experiment and the instantaneous frequency obtained by the IR-HHT algorithm. . In addition, the pitch frequency f _θ (see 18) and the roll natural frequency f _roll (see 19) are also included in FIG.

As can be seen from Fig. 7, the roll angle 15 is continuously increased when the parameter roll occurs, and the instantaneous frequency 17 is abruptly changed from the pitch frequency 18 to the roll natural frequency 19, and the advance warning algorithm warns the time 20 at which the parameter roll occurs. At this point, the amplitude of the parameter roll is still small.

It can be seen from the experimental results that the algorithm and device for predicting the premature motion of the parametric resonance motion proposed by the present invention can perform prediction when the amplitude of the parametric resonance motion is small, so as to adopt corresponding evasive measures, and the safety of the marine floating structure can be effectively guaranteed.

In addition, the present invention also includes a storage medium including: a ROM, a RAM, a magnetic disk, or an optical disk, and the like, which can store a program code, wherein the computer program is stored, and the computer program is processed. When the load is performed, all or part of the steps of the early warning method for resonating the parameters of the marine floating structure in the foregoing embodiment are implemented. Since the technical features in the foregoing embodiments can be applied to the present embodiment, the description thereof will not be repeated.

Specifically, as shown in FIG. 8, the computer program is implemented based on the following modules:

The signal acquisition module 801 acquires motion signals of different degrees of freedom of the marine floating structure collected in real time.

The signal processing module 802 first linearly superimposes the time history data of the different motion signals to obtain time history data of the combined signals. Then, generating instantaneous frequency history data of the instantaneous frequency of the combined signal according to the time history data of the combined signal, for example, analyzing the time history of the combined signal based on an incremental real-time Hilbert-Huang algorithm Obtaining an instantaneous frequency of the time-frequency information including the combined signal, comprising: screening from the combined signal (eg, based on an empirical mode decomposition algorithm) all modal functions that are locally symmetric to the mean zero; The modal function performs a Hilbert transform to find the instantaneous frequency. Subsequently, it is recognized from the instantaneous frequency history data that the frequency abrupt change is caused by a frequency doubling relationship between motion signals at least two degrees of freedom when the parametric resonance motion occurs.

The resonance warning module 803 calculates, according to the frequency mutation, a time at which the parameter resonance motion occurs for early warning, for example, preprocessing the curve of the instantaneous frequency (eg, based on a moving average algorithm) to eliminate the error data point; The instantaneous frequency f _MA (t) after pre-processing, the establishment condition Γ ₁ and condition Γ ₂ :

Where t _h is the time of the Gibbs peak point, μ ₁ is the parameter, and the frequency drop amplitude α represents the magnitude of the frequency decrease relative to the average frequency f _Average (t _h ) in the interval [0, t _h ], α _cr is The preset critical frequency decreases.

Where Θ _PR is the rate of change threshold, above which the parameter resonance motion may occur, and below this threshold value is not the frequency change caused by the parameter resonance. Optionally, the rate-of-change threshold Θ _{PR is} set to a ratio of a difference between a natural frequency of the target motion signal and a natural frequency of a motion signal that forms a frequency multiplication relationship with the target motion signal, and a transition time, where The transition time is the sum of the natural period of the target motion signal and the natural period of the motion signal that forms a multiplication relationship with the target motion signal.

At this time, the time t _{p =} t _h + μ ₁ T _S2 at which the parametric resonance motion occurs is calculated.

In summary, the method, apparatus, storage medium and equipment for detecting the parametric resonance motion of the marine floating structure effectively overcome various disadvantages in the prior art and have high industrial utilization value.

The above-described embodiments are merely illustrative of the principles of the invention and its effects, and are not intended to limit the invention. Modifications or variations of the above-described embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and scope of the invention are still to be covered by the appended claims.

Claims

An early warning method for parameter resonance motion of marine floating structures, characterized in that it comprises:

Obtaining motion signals of different degrees of freedom of the marine floating structure collected in real time;

Linearly superimposing the time history data of the different motion signals to obtain time history data of the combined signal;

Generating instantaneous frequency history data of the instantaneous frequency of the combined signal as a function of time according to the time history data of the combined signal;

Identifying a frequency mutation from the instantaneous frequency history data; wherein the frequency mutation is caused by a frequency doubling relationship between motion signals at least two degrees of freedom when the parametric resonance motion occurs;

The time at which the parametric resonance motion occurs is calculated based on the frequency mutation for early warning.
The method according to claim 1, wherein the generating the instantaneous frequency time history data according to the time history data of the combined signal is implemented based on an incremental real-time Hilbert-Huang algorithm.
The method according to claim 1, wherein the calculating the moment at which the parametric resonance motion occurs according to the mutation of the frequency comprises:

Establish condition Γ1 and condition Γ 2 :

Where f MA (t) is the instantaneous frequency, t h is the time of the Gibbs peak point, μ 1 is the parameter, T S2 is the natural period of the target motion signal, and the frequency falling amplitude α indicates the frequency relative to [0, t h The amplitude of the average frequency f Average (t h ) in the interval, α cr is the preset critical frequency falling amplitude;

Where Θ PR is the rate of change threshold, above which the parameter resonance motion may occur, and below this threshold value is not the frequency change caused by the parameter resonance;

Based on the condition Γ1 and the condition Γ 2 , the time t p = t h + μ 1 T S2 at which the parametric resonance motion occurs is calculated.
The method according to claim 3, wherein said rate of change threshold Θ PR is set to: a difference between a natural frequency of said target motion signal and a natural frequency of a motion signal that forms a frequency multiplication relationship with said target motion signal a ratio of a value to a transition time, wherein the transition time is a sum of a natural period of the target motion signal and a natural period of a motion signal that forms a multiplication relationship with the target motion signal.
The method according to claim 3, characterized in that before the time when the parameter resonance motion is calculated according to the condition Γ1 and the condition Γ 2 , the method further comprises:

Pre-processing the instantaneous frequency time history data to eliminate data points caused by numerical errors;

The pre-processed instantaneous frequency history data is substituted as the instantaneous frequency f MA (t) into the condition Γ 1 and the condition Γ 2 for calculation.
The method of claim 5 wherein said pre-processing is implemented based on a moving average algorithm.
An early warning device for parameter resonance motion of a marine floating structure, characterized in that it comprises:

a signal acquisition module, configured to acquire motion signals of different degrees of freedom of the marine floating structure collected in real time;

a signal processing module, configured to linearly superimpose the time history data of the different motion signals to obtain time history data of the combined signal; and generate an instantaneous frequency of the instantaneous frequency of the combined signal according to the time history data of the combined signal Time history data; identifying a frequency mutation from the instantaneous frequency history data; wherein the frequency mutation is caused by a frequency doubling relationship between motion signals at least two degrees of freedom when the parameter resonance motion occurs;

The resonance warning module is configured to calculate, according to the frequency mutation, a moment when the parameter resonance motion occurs for early warning.
The apparatus according to claim 7, wherein the signal processing module generates the instantaneous frequency time history data according to the time history data of the combined signal is implemented based on an incremental real-time Hilbert-Huang algorithm.
The apparatus according to claim 7, wherein the moment when the resonance early warning module calculates the parameter resonance motion based on the frequency abrupt change is realized by:

Establish condition Γ1 and condition Γ 2 :

Where f MA (t) is the instantaneous frequency, t h is the time of the Gibbs peak point, μ 1 is the parameter, T S2 is the natural period of the target motion signal, and the frequency falling amplitude α indicates the frequency relative to [0, t h The amplitude of the average frequency f Average (t h ) in the interval, α cr is the preset critical frequency falling amplitude;

Where Θ PR is the rate of change threshold, above which the parameter resonance motion may occur, and below this threshold value is not the frequency change caused by the parameter resonance;

Based on the condition Γ1 and the condition Γ 2 , the time t p = t h + μ 1 T S2 at which the parametric resonance motion occurs is calculated.
The apparatus according to claim 9, wherein said change rate threshold Θ PR is set to: a difference between a natural frequency of said target motion signal and a natural frequency of a motion signal that forms a frequency multiplication relationship with said target motion signal a ratio of a value to a transition time, wherein the transition time is a sum of a natural period of the target motion signal and a natural period of a motion signal that forms a multiplication relationship with the target motion signal.
The apparatus according to claim 9, further comprising: a data pre-processing module, configured to pre-process the instantaneous frequency time history data before the resonance early warning module calculates a time at which the parameter resonance motion occurs Processing to eliminate data points caused by numerical errors; the pre-processed instantaneous frequency time history data is substituted as the instantaneous frequency f MA (t) into the condition Γ 1 and condition Γ 2 for calculation.
The apparatus of claim 11 wherein said pre-processing is implemented based on a moving average algorithm.
A storage medium storing a computer program, wherein the computer program is loaded by a processor to implement an early warning method for resonating motion of a marine floating structure according to any one of claims 1 to 6. .
An electronic device, comprising: a processor, and a memory; wherein

The memory is for storing a computer program;

The processor is configured to load an early warning method for performing the computer program to cause the electronic device to perform a resonant motion of a marine floating structure parameter according to any one of claims 1 to 6.
An early warning system for parametric resonance movement of marine floating structures, characterized in that it comprises:

An angular motion detecting device is disposed on the marine floating structure for real-time collecting motion signals of different degrees of freedom of the marine floating structure;

The electronic device of claim 14 communicatively coupled to said angular motion detecting means.