Method for synchronously monitoring internal and external leakage of blow-off valve based on optical fiber array

Abstract

The invention relates to the technical field of signal decomposition, in particular to a synchronous monitoring method for internal and external leakage of a blow-off valve based on an optical fiber array, which comprises the following steps of: firstly, determining an optimal linear characteristic parameter by utilizing a leakage linear relation according to a continuity characteristic of a time domain signal of each place in a time domain; a more accurate internal leakage signal separation graph and an accurate external leakage signal separation graph are separated in the frequency domain according to the frequency attenuation stability characteristic of internal leakage and the high-frequency concentration stability characteristic of external leakage in combination with the optimal linear characteristic parameter and the frequency law condition in the spatial domain; therefore, synchronous monitoring of internal leakage and external leakage of the blow-off valve can be carried out more accurately according to the internal leakage signal separation diagram and the external leakage signal separation diagram.

Description

Technical Field

[0001] This invention relates to the field of signal decomposition technology, specifically to a method for synchronous monitoring of internal and external leakage of a venting valve based on an optical fiber array. Background Technology

[0002] A vent valve is a safety device used in pressure vessels or pipeline systems. It is typically used to release excess gas or liquid when the internal pressure exceeds a set value, thus preventing damage or explosion due to overpressure. Simultaneous monitoring of internal and external leaks in vent valves is crucial. Internal leaks refer to gas or liquid leakage occurring inside the vent valve, while external leaks refer to leakage at the valve's external connections. Real-time monitoring of both internal and external leaks allows for timely detection and location of leak sources, preventing accidents, improving emergency response efficiency, and ensuring the safety and stability of the pipeline system.

[0003] Existing technologies typically rely on empirical mode decomposition (EMD) to decompose vibration signals and separate external and internal leakage signals, enabling simultaneous monitoring of internal and external leakage in venting valves. However, when both internal and external leakage occur simultaneously in a pipeline system, the vibration signals received by the DAS system are not simply a parallel sequence of two independent events. Instead, the vibrations generated during their physical propagation are linearly superimposed in both the time and frequency domains. This superposition effect makes it extremely difficult to accurately separate the individual source signals from the mixed signal, resulting in low accuracy of the external and internal leakage signals decomposed by EMD. Summary of the Invention

[0004] To address the low accuracy of external and internal leakage signals obtained from existing empirical mode decomposition methods, this application aims to provide a method for synchronous monitoring of internal and external leakage in venting valves based on fiber optic arrays. The specific technical solution adopted is as follows:

[0005] The first aspect of this application provides a method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array, including:

[0006] Vibration time-domain images of each location in the spatial domain are acquired at the starting point of the fiber optic array using a DAS demodulator; the vibration time-domain images are then converted to time-frequency data to determine the corresponding vibration spectrum.

[0007] On the vibration time-domain diagram, based on the stability of the vibration signal value change and the linearity of the vibration signal values ​​at all locations along the pipe wall conduction direction in terms of internal and external leakage, the corresponding optimal linear characteristic parameters are determined.

[0008] Based on the stable attenuation of low-frequency amplitude in the vibration spectrum, the optimal linear characteristic parameter, and the consistency of frequency values ​​at all locations along the pipe wall conduction direction with the internal leakage pattern, an internal leakage signal separation diagram is determined; based on the stable concentration of high-frequency amplitude in the vibration spectrum, the optimal linear characteristic parameter, and the consistency of frequency values ​​at all locations along the pipe wall conduction direction with the external leakage pattern, an external leakage signal separation diagram is determined.

[0009] Synchronous monitoring of internal and external leakage of the vent valve is performed based on the internal leakage signal separation diagram and the external leakage signal separation diagram.

[0010] Furthermore, the process of obtaining the optimal linear feature parameters includes:

[0011] On the vibration time-domain diagram, the instantaneous stationary weight of each location at each sampling time is determined based on the deviation of vibration signal value changes between adjacent sampling times; at each sampling time, the vibration signal values ​​of all locations are arranged sequentially along the pipe wall conduction direction to determine the vibration signal value sequence of each sampling time.

[0012] A rectangular coordinate system is constructed with the location along the direction of transmission along the pipe wall as the horizontal axis and the vibration signal value as the vertical axis; the data points corresponding to each location in the vibration signal value sequence on the rectangular coordinate system are obtained;

[0013] The optimal leakage fitting curve is determined by fitting the objective function using the least squares method based on all data points in the rectangular coordinate system. The objective function is obtained by superimposing a linear function and an external leakage reference function. The external leakage reference function is a piecewise function composed of two line segments that form an isosceles triangle with the x-axis. The internal leakage residual corresponding to the optimal leakage fitting curve is obtained by the deviation between the vibration signal value at each location and the optimal leakage fitting curve, as well as the corresponding instantaneous stationary weight.

[0014] Based on the slope distribution of the optimal leakage fitting curve at each sampling time, the corresponding optimal linear characteristic parameters are determined.

[0015] Furthermore, the process of obtaining the instantaneous stationary weights includes:

[0016] On the vibration time-domain graph, the local vibration change value at each sampling time is determined based on the difference between the vibration signal value at each location at each sampling time and the vibration signal value at the previous sampling time; the difference between the local vibration change value at each sampling time and the local vibration change value at the next sampling time is negatively correlated and mapped to determine the instantaneous stationary weight of each location at each sampling time.

[0017] Furthermore, the process of determining the corresponding optimal linear feature parameters based on the slope distribution changes of the optimal leakage fitting curve at each sampling time includes:

[0018] The slope value of the linear function that constitutes the optimal leakage fitting curve at each sampling time is used as the internal leakage slope parameter at each sampling time. The difference between the internal leakage slope parameter at each sampling time and the internal leakage slope parameter at the previous sampling time is negatively correlated and normalized to determine the contribution weight of the internal leakage parameter at each sampling time. The contribution value of the corresponding internal leakage parameter is determined by multiplying the internal leakage slope parameter at each sampling time with the contribution weight of the internal leakage parameter. The optimal linear characteristic parameter corresponding to the internal leakage is determined by accumulating the contribution values ​​of the internal leakage parameters at all sampling times.

[0019] The maximum slope of the two line segments corresponding to the external leakage reference function that constitute the optimal leakage fitting curve at each sampling time is taken as the external leakage slope parameter at each sampling time. Based on the principle of obtaining the optimal linear characteristic parameter corresponding to internal leakage, the optimal linear characteristic parameter corresponding to external leakage is determined based on the external leakage slope parameter.

[0020] Furthermore, the process of obtaining the sum of internal leakage residuals includes:

[0021] At each sampling time, the difference between the vibration signal value corresponding to each location and the corresponding fitted value on the optimal leakage fitting curve is taken as the initial residual value for each location; the product between the initial residual value for each location and the corresponding instantaneous stationary weight is used to determine the corresponding weighted residual value; the sum of the weighted residual values ​​for all locations at each sampling time is used to determine the corresponding internal leakage residual sum.

[0022] Furthermore, the process of obtaining the internal leakage signal separation map includes:

[0023] Based on the frequency stability of the vibration spectrum, determine the frequency stability weight for each frequency;

[0024] The product of the negative correlation mapping value of each frequency value and the corresponding frequency amplitude is used to determine the corresponding internal leakage frequency characteristic value; the product of the frequency stability weight and the internal leakage frequency characteristic value is normalized to determine the internal leakage correlation of each location at each frequency.

[0025] At each frequency, the frequency amplitudes of all locations along the pipe wall conduction direction are sequentially arranged on the corresponding vibration spectrum diagram and then a straight line is fitted to determine the internal leakage characteristic fitting line corresponding to each frequency; the internal leakage characteristic residual corresponding to the internal leakage characteristic fitting line is obtained by the deviation between the frequency amplitude corresponding to each location and the internal leakage characteristic fitting line and the corresponding internal leakage correlation.

[0026] Based on the similarity between the slope of the fitted line of internal leakage characteristics and the optimal linear characteristic parameters of internal leakage, as well as the amplitude distribution on the fitted line of internal leakage characteristics, the amplitude of internal leakage frequency at each location at each frequency is determined.

[0027] Based on the internal leakage frequency amplitude at all frequencies at each location, determine the final internal leakage spectrum diagram for each location; perform time-frequency conversion based on the final internal leakage spectrum diagrams for each location to determine the internal leakage signal separation diagram.

[0028] Furthermore, the process of obtaining the frequency stabilization weight includes:

[0029] On the vibration spectrum, the difference between the frequency amplitude of each frequency and the frequency amplitude of the previous frequency is taken as the amplitude change value of each frequency; the difference between the amplitude change value of each frequency and the frequency change value of the next frequency is negatively correlated and mapped to determine the frequency stability weight of each frequency.

[0030] Furthermore, the process of obtaining the sum of the internal leakage characteristic residuals includes:

[0031] The difference between the frequency amplitude corresponding to each frequency on the vibration spectrum of each location and the corresponding fitted frequency amplitude on the internal leakage characteristic fitting line is used to determine the corresponding internal leakage fitting deviation value.

[0032] The internal leakage local error value at each location at each frequency is determined by multiplying the internal leakage correlation at each frequency with the internal leakage fitting deviation value; the internal leakage characteristic residual of the internal leakage characteristic fitting line corresponding to each frequency is determined by summing the internal leakage local error values ​​at all locations at each frequency.

[0033] Furthermore, the process of obtaining the internal leakage frequency amplitude includes:

[0034] Based on the amplitude corresponding to each location on the internal leakage feature fitting line, determine the fitting frequency amplitude at each location at each frequency; perform a negative correlation mapping between the slope of the internal leakage feature fitting line corresponding to each frequency and the difference between the optimal linear feature parameters of the internal leakage, and determine the internal leakage reference weight at each frequency; multiply the fitting frequency amplitude corresponding to each location on the internal leakage feature fitting line and the internal leakage reference weight to determine the internal leakage frequency amplitude at each location at each frequency.

[0035] Furthermore, the process of obtaining the external leakage signal separation map includes:

[0036] On the vibration spectrum, the product of the normalized value of each frequency value and the corresponding frequency amplitude is used to determine the corresponding external leakage frequency characteristic value; the product of the frequency stability weight and the external leakage frequency characteristic value is normalized to determine the external leakage correlation at each location at each frequency.

[0037] At each frequency, the frequency amplitudes of all locations along the pipe wall conduction direction on the corresponding vibration spectrum are arranged sequentially and then a straight line is fitted to determine the fitting straight line of the external leakage characteristic corresponding to each frequency.

[0038] Based on the principle of obtaining the internal leakage signal separation map, the external leakage signal separation map is determined according to the fitting line of the external leakage characteristics and the external leakage correlation.

[0039] Secondly, this application provides a synchronous monitoring system for internal and external leakage of a vent valve based on a fiber optic array, the system comprising:

[0040] The data acquisition and preprocessing module is used to acquire vibration time-domain images of each location in the spatial domain at the starting point of the fiber array using a DAS demodulator; and to perform time-frequency conversion on the vibration time-domain images to determine the corresponding vibration spectrum.

[0041] The first determining module is used to determine the corresponding optimal linear characteristic parameters on the vibration time-domain diagram based on the stability of the change in vibration signal values ​​and the linearity of vibration signal values ​​at all locations along the pipe wall conduction direction in terms of internal and external leakage.

[0042] The second determining module is used to determine the internal leakage signal separation diagram based on the stable attenuation of low-frequency amplitude in the vibration spectrum diagram, the optimal linear characteristic parameter, and the conformity of frequency values ​​at all locations along the pipe wall conduction direction with the internal leakage pattern; and to determine the external leakage signal separation diagram based on the stable concentration of high-frequency amplitude in the vibration spectrum diagram, the optimal linear characteristic parameter, and the conformity of frequency values ​​at all locations along the pipe wall conduction direction with the external leakage pattern.

[0043] The leakage monitoring module is used to simultaneously monitor internal and external leakage of the vent valve based on the internal leakage signal separation diagram and the external leakage signal separation diagram.

[0044] Thirdly, this application provides a computer device including a memory and a processor. The memory is used to store computer program code, and the processor is used to call and run the computer program code from the memory to perform the method as described in the first aspect of this application or any embodiment of the first aspect.

[0045] Fourthly, this application provides a computer program product comprising computer program code, which, when executed, performs the method as described in the first aspect of this application or any embodiment thereof.

[0046] Fifthly, this application provides a computer-readable storage medium that stores computer program code, which, when executed, performs the method as described in the first aspect of this application or any embodiment thereof.

[0047] This application has the following beneficial effects:

[0048] This application first determines the optimal linear characteristic parameters in the time domain based on the continuity characteristics of the time domain signals at various locations and the linear relationship of leakage. Then, in the frequency domain, based on the frequency attenuation stability characteristics of internal leakage and the high-frequency concentrated stability characteristics of external leakage, combined with the optimal linear characteristic parameters and the frequency law in the spatial domain, a more accurate internal leakage signal separation diagram and external leakage signal separation diagram are obtained. Thus, more accurate synchronous monitoring of internal and external leakage of the relief valve is performed based on the internal leakage signal separation diagram and the external leakage signal separation diagram. Attached Figure Description

[0049] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 A flowchart of a method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array, provided as an embodiment of the present invention;

[0051] Figure 2 This is a structural diagram of a fiber optic array-based synchronous monitoring system for internal and external leakage of a vent valve, provided in one embodiment of the present invention.

[0052] Figure 3This is a schematic diagram of a computer device structure provided in one embodiment of the present invention. Detailed Implementation

[0053] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a fiber optic array-based method for synchronous monitoring of internal and external leakage of a venting valve, as proposed by the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment, and specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0055] The following description, in conjunction with the accompanying drawings, details a specific scheme for a method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array, provided by the present invention.

[0056] This application provides a method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array. Please refer to [link to relevant documentation]. Figure 1 The diagram illustrates a flowchart of a method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array, according to an embodiment of the present invention. The method includes:

[0057] Step S101: At the starting point of the fiber optic array, the vibration time-domain diagram of each location in the spatial domain is acquired using a DAS demodulator; the vibration time-domain diagram is converted to time and frequency to determine the corresponding vibration spectrum diagram.

[0058] A DAS demodulator is installed at the starting point of the fiber optic array. This device transmits optical pulses at a frequency of 1 kHz (i.e., 1,000 times per second) into the sensing fiber and simultaneously receives backscattered signals (Rayleigh scattering) generated by microscopic inhomogeneities within the fiber. The core function of the demodulator is to compare the phase difference between the backscattered signals corresponding to two consecutive optical pulses. This phase difference is proportional to the minute deformation (i.e., microstrain) of the fiber within the pulse interval. By measuring this phase difference, the amount of microstrain change at each sensing point along the fiber (spatial resolution typically one meter) can be accurately calculated.

[0059] For each sensing point, the continuously recorded microstrain data over time constitutes a microstrain time series. This series is essentially a complete "vibration recording" of the vibration state at that point, containing acoustic information caused by leakage. Therefore, the corresponding microstrain time series is further subjected to curve fitting to determine the vibration time-domain map of each location in the spatial domain.

[0060] Considering that subsequent analysis needs to be performed in the frequency domain, a time-frequency transformation is further performed on the vibration time-domain diagram to determine the corresponding vibration spectrum. Specifically, a Fourier transform is performed on the vibration time-domain diagram to determine the corresponding vibration spectrum.

[0061] Step S102: On the vibration time-domain diagram, based on the stability of the vibration signal value change and the linearity of the vibration signal values ​​at all locations along the pipe wall transmission direction in terms of internal and external leakage, determine the corresponding optimal linear characteristic parameters.

[0062] Internal leakage occurs inside the pipe, and the energy of its vibrations (turbulence, gas impacting the pipe wall) is conducted through the pipe wall itself. The pipe can be considered as a waveguide, with vibration energy propagating along its axis. During propagation, the energy decreases linearly with distance due to internal friction (damping) of the material. External leakage, on the other hand, is the ejection of gas into the atmosphere. Its vibration originates at the leak point and propagates outwards through external media such as soil and supports. The key difference is that the propagation and attenuation mechanisms of vibration from the point source in two opposite directions (e.g., left and right along an optical fiber) are independent and symmetrical. For each side, the vibration intensity also follows an approximately linear attenuation law with increasing distance. To determine the corresponding law for subsequent signal separation, this embodiment of the invention determines the corresponding optimal linear characteristic parameters on the vibration time-domain diagram based on the stability of the vibration signal value change and the linearity of the vibration signal values ​​at all locations along the pipe wall propagation direction for internal and external leakage. The optimal linear characteristic parameters are used to characterize the spatial variation law of the signal in internal and external leakage, respectively.

[0063] Preferably, in some possible implementations of the embodiments of the present invention, the process of obtaining the optimal linear feature parameters includes:

[0064] On the vibration time-domain graph, based on the deviation of vibration signal value changes between adjacent sampling times, the instantaneous stationarity weight of each location at each sampling time is determined. Preferably, in some possible implementations of the embodiments of the present invention, the process of obtaining the instantaneous stationarity weight includes: on the vibration time-domain graph, based on the difference between the vibration signal value of each location at each sampling time and the vibration signal value at the previous sampling time, determining the local vibration change value at each sampling time; and performing a negative correlation mapping between the difference between the local vibration change value at each sampling time and the local vibration change value at the next sampling time to determine the instantaneous stationarity weight of each location at each sampling time.

[0065] Because leakage is a continuous energy release process, while many disturbances are transient impact events, both internal and external leakage exhibit continuity in the time domain. Compared to valve switching or hammering, internal leakage is a physical process where high-pressure gas continuously flows from a constant (or slowly changing) leak point inside a pipe to a low-pressure end. The pressure fluctuations applied to the pipe wall are a continuous random process. Therefore, the micro-strain signal generated on the optical fiber is highly correlated in time, with minimal difference in vibration state between adjacent moments. Compared to interference from raindrops or wind blowing through cables, external leakage is a process where gas is continuously ejected from a crack into the atmosphere, forming a stable jet stream. This jet stream violently rubs against the surrounding air, generating vortices that detach. As long as the pipe pressure is stable, this sound source is stable, and its vibration signal is also continuous and stable. Therefore, the larger the corresponding instantaneous stability weight, the more it conforms to the signal change stability characteristics of both internal and external leakage, and the higher the signal reliability at the corresponding sampling time.

[0066] In one specific implementation of this invention, the process of obtaining the instantaneous stationary weights is expressed by the following formula: ;in, For the first At the sampling time, each location The instantaneous stationary weights below; It is a linear normalization function; For the first At the sampling time, each location The local vibration change value at the sampling time If there is no previous sampling time, the average of the vibration signal values ​​at all other sampling times is used as the sampling time. The vibration signal value at the previous sampling time is used as the sampling time. Calculation of local vibration variation values; For the first At the sampling time, each location The local vibration change value at the next sampling time, when the sampling time If there is no next sampling time, use 0 as the sampling time. The local vibration change value at the next sampling time is calculated.

[0067] At each sampling time, the vibration signal values ​​of all locations along the pipe wall conduction direction are arranged sequentially to determine the vibration signal value sequence at each sampling time. A rectangular coordinate system is constructed with the locations along the pipe wall conduction direction as the horizontal axis and the vibration signal values ​​as the vertical axis. Data points corresponding to each location in the vibration signal value sequence on the rectangular coordinate system are obtained. Based on all data points on the rectangular coordinate system, the objective function is fitted using the least squares method to determine the corresponding optimal leakage fitting curve. The objective function is obtained by superimposing a linear function and an external leakage reference function. The external leakage reference function is a piecewise function composed of two line segments that form an isosceles triangle with the x-axis. The internal leakage residual corresponding to the optimal leakage fitting curve is obtained by the deviation between the vibration signal value corresponding to each location and the optimal leakage fitting curve, as well as the corresponding instantaneous stationary weight.

[0068] Considering that the vibration energy corresponding to internal leakage exhibits linear decay, the internal leakage vibration signal should normally exhibit a linear function form in the spatial domain. External leakage vibration, triggered by the power source, decays in two opposite directions, exhibiting a linear decay characteristic from a single point in both directions. Therefore, the external leakage reference function is a piecewise function composed of two line segments, forming an isosceles triangle with the x-axis. To more accurately characterize the signal characteristics of the superimposed internal and external leakage vibration signals, this embodiment of the invention obtains a target function by superimposing a linear function and the external leakage reference function. Then, a least-squares method is used to fit the target function, resulting in an optimal leakage fitting curve that more accurately characterizes the overall spatial characteristics of both internal and external leakage signals. Subsequently, the optimal linear characteristic parameters for both internal and external leakage are determined more accurately as a whole.

[0069] In one specific implementation of this invention, the function expression corresponding to the linear function constituting the objective function is as follows: The function expression corresponding to the external leakage reference function that constitutes the objective function is as follows: Among them, the two function expressions All are dependent variables. All are independent variables; The slope of the linear function that constitutes the objective function; The intercept of the linear function that constitutes the objective function; The external leakage reference function that constitutes the objective function is when the independent variable is less than or equal to Slope under the given conditions; The external leakage reference function that constitutes the objective function is when the independent variable is greater than Slope under the given conditions; The x-axis coordinate value of the location corresponding to the point source in the rectangular coordinate system; and , , , , These are all constants that need to be solved when fitting using the least squares method, and will not be elaborated further here.

[0070] Furthermore, based on the principle of least squares, the internal leakage residual sum corresponding to the optimal leakage fitting curve is obtained by the deviation between the vibration signal value at each location and the optimal leakage fitting curve, as well as the corresponding instantaneous stationary weight. Specifically, the process of obtaining the internal leakage residual sum includes: at each sampling time, taking the difference between the vibration signal value at each location and the corresponding fitted value on the optimal leakage fitting curve as the initial residual value at each location; multiplying the initial residual value at each location with the corresponding instantaneous stationary weight to determine the corresponding weighted residual value; and determining the corresponding internal leakage residual sum based on the cumulative value of the weighted residual values ​​at all locations at each sampling time.

[0071] The internal leakage residual sum represents the overall size of the residuals when fitted using the least squares method. According to the principle of the least squares method, the internal leakage residual sum corresponding to the optimal leakage fitting curve is the minimum among all objective functions. In this embodiment of the invention, considering that the greater the instantaneous stationary weight, the higher the reliability of the corresponding signal data, the initial residual value is weighted with the instantaneous stationary weight when calculating the residual, which can make the final internal leakage residual sum more accurate.

[0072] The optimal linear characteristic parameter essentially characterizes the energy attenuation characteristics of internal or external leakage. The optimal leakage fitting curve is obtained from a linear function with a relatively obvious slope and an external leakage reference function. Therefore, the corresponding optimal linear characteristic parameter is further determined based on the slope distribution changes of the optimal leakage fitting curve at each sampling time. Preferably, in some possible implementations of this invention, the process of determining the corresponding optimal linear characteristic parameter based on the slope distribution changes of the optimal leakage fitting curve at each sampling time includes:

[0073] The slope value of the linear function that constitutes the optimal leakage fitting curve at each sampling time is used as the internal leakage slope parameter at each sampling time. The difference between the internal leakage slope parameter at each sampling time and the internal leakage slope parameter at the previous sampling time is negatively correlated and normalized to determine the contribution weight of the internal leakage parameter at each sampling time. The contribution value of the corresponding internal leakage parameter is determined by multiplying the internal leakage slope parameter at each sampling time with the contribution weight of the internal leakage parameter. The optimal linear characteristic parameter corresponding to the internal leakage is determined by accumulating the contribution values ​​of the internal leakage parameters at all sampling times.

[0074] Since the damping characteristics and geometry of the pipe material are fixed, the optimal linear characteristic parameter characterizing the attenuation rate is stable under normal conditions and usually does not show drastic changes. Therefore, for the optimal linear characteristic parameter at each sampling time, the more stable its instantaneous change, the higher the reliability of its corresponding optimal linear characteristic parameter. Therefore, the internal leakage slope parameter is weighted by the contribution weight of the internal leakage parameter to finally determine a more accurate optimal linear characteristic parameter.

[0075] In one specific implementation of this invention, the process of obtaining the contribution value of the internal leakage parameter is expressed by the following formula: ;in, Sampling time The contribution value of internal leakage parameters; Sampling time The contribution value of internal leakage parameters; Sampling time The internal leakage slope parameter at the previous sampling time, where, at sampling time... If there is no previous sampling time, the average value of the internal leakage slope parameter at all other sampling times is used as the sampling time. The internal leakage slope parameter at the previous sampling time is calculated, which will not be elaborated further here; It is the absolute value symbol; Sampling time The negative correlation mapping value between the internal leakage slope parameter and the internal leakage slope parameter at the previous sampling time; It is a linear normalization function; other normalization methods may be adopted depending on the specific implementation environment. The softmax function is used for normalization, which makes the sum of the contribution values ​​of the internal leakage parameters at all sampling times equal to 1. This is used to cooperate with the subsequent accumulation calculation based on the contribution values ​​of the internal leakage parameters at all sampling times, so that the optimal linear characteristic parameters corresponding to the internal leakage are more accurate.

[0076] Regarding the optimal linear characteristic parameter corresponding to external leakage, considering that both the optimal linear characteristic parameter corresponding to external leakage and the optimal linear characteristic parameter corresponding to internal leakage characterize the energy decay law, the principle for obtaining the optimal linear characteristic parameter corresponding to external leakage is the same as that for internal leakage. However, considering that the external leakage reference function corresponding to external leakage corresponds to two line segments, that is, there are two slope values, in order to match the analysis process with the internal leakage slope parameter, in this embodiment of the invention, among the two slopes corresponding to the two line segments of the external leakage reference function that constitute the optimal leakage fitting curve at each sampling time, the slope with the same positive and negative signs as the internal leakage slope parameter is taken as the external leakage slope parameter at each sampling time.

[0077] Furthermore, based on the principle of obtaining the optimal linear characteristic parameter corresponding to internal leakage, the optimal linear characteristic parameter corresponding to external leakage is determined based on the external leakage slope parameter. Specifically: the difference between the external leakage slope parameter at each sampling time and the external leakage slope parameter at the previous sampling time is negatively correlated and normalized to determine the contribution weight of the external leakage parameter at each sampling time; the contribution value of the corresponding external leakage parameter is determined based on the product between the external leakage slope parameter at each sampling time and the contribution weight of the external leakage parameter; and the optimal linear characteristic parameter corresponding to external leakage is determined based on the cumulative value of the contribution values ​​of the external leakage parameter at all sampling times.

[0078] In one specific implementation of this invention, the process of obtaining the contribution value of the external leakage parameter is expressed by the following formula: ;in, Sampling time Contribution value of external leakage parameters; Sampling time The contribution value of external leakage parameters; Sampling time The external leakage slope parameter at the previous sampling time, where, at the sampling time... If there is no previous sampling time, the average value of the external leakage slope parameter of all other sampling times is used as the sampling time. The external leakage slope parameter at the previous sampling time is calculated, which will not be elaborated further here; It is the absolute value symbol; Sampling time The negative correlation mapping value between the external leakage slope parameter and the external leakage slope parameter at the previous sampling time; It is a linear normalization function; other normalization methods may be adopted depending on the specific implementation environment. The softmax function is used for normalization, ensuring that the sum of the external leakage parameter contributions at all sampling times equals 1. This is used in subsequent summation calculations based on the external leakage parameter contributions at all sampling times, resulting in a more accurate optimal linear characteristic parameter corresponding to the external leakage. Since the principle for obtaining the optimal linear characteristic parameter corresponding to the external leakage is the same as that for the internal leakage, it will not be elaborated further here.

[0079] Step S103: Determine the internal leakage signal separation diagram based on the stable low-frequency amplitude attenuation in the vibration spectrum diagram, the optimal linear characteristic parameter, and the conformity of the frequency values ​​at all locations along the pipe wall conduction direction to the internal leakage. Determine the external leakage signal separation diagram based on the stable high-frequency amplitude concentration in the vibration spectrum diagram, the optimal linear characteristic parameter, and the conformity of the frequency values ​​at all locations along the pipe wall conduction direction to the external leakage.

[0080] For internal leakage, it refers to the turbulent flow of gas inside the pipe, with its energy transferred to the optical fiber through the pipe wall. The pipe wall, as a large-mass, high-inertia mechanical structure, has a significant filtering and attenuation effect on high-frequency vibrations, acting like a low-pass filter, thus primarily allowing low-frequency components to propagate effectively. Simultaneously, the turbulence itself consists of a series of vortices of different scales; large-scale vortices generate low-frequency energy, while small-scale vortices generate high-frequency energy, and the energy decreases with increasing frequency. This distribution pattern precisely reflects the pink noise characteristic of a continuous spectrum with a smooth decrease in amplitude as frequency increases. Therefore, further analysis of the stable attenuation characteristics of low-frequency amplitude in the vibration spectrum is needed. Furthermore, the linear distribution of internal leakage in the spatial domain is essentially a manifestation of the attenuation of vibration energy with propagation distance, and the optimal linear characteristic parameter quantitatively describes the rate of this attenuation. Therefore, this embodiment of the invention integrates characteristics in the time, frequency, and spatial domains, and determines the internal leakage signal separation diagram based on the stable attenuation of low-frequency amplitude in the vibration spectrum, the optimal linear characteristic parameter, and the conformity of frequency values ​​at all locations along the pipe wall propagation direction in the internal leakage.

[0081] Preferably, in some possible implementations of the embodiments of the present invention, the process of obtaining the internal leakage signal separation map includes:

[0082] Based on the frequency stability of the vibration spectrum, the frequency stability weight of each frequency is determined. The process of obtaining the frequency stability weight includes: on the vibration spectrum, taking the difference between the frequency amplitude of each frequency and the frequency amplitude of the previous frequency as the amplitude change value of each frequency; and performing a negative correlation mapping between the amplitude change value of each frequency and the frequency change value of the next frequency to determine the frequency stability weight of each frequency.

[0083] Under normal circumstances, internal leakage exhibits pink noise characteristics with a continuous spectrum and a smooth decrease in amplitude as the frequency increases. External leakage, dominated by high frequencies and characterized by a "jet-like" spectrum, involves gas ejection into the atmosphere, forming a high-speed jet. This jet undergoes intense shearing and friction with the surrounding still air, and through mechanisms such as vortex shearing, it directly injects a large amount of energy into the high-frequency and even ultrasonic bands. Its vibrations act directly on the fiber optic sheath through media such as air or soil, resulting in relatively small attenuation of the high-frequency components and relatively stable values. Therefore, its spectral energy is highly concentrated within a specific high-frequency bandwidth and remains stable. In other words, under normal circumstances, internal leakage exhibits low-frequency characteristics with relatively stable energy attenuation in the frequency domain, while external leakage exhibits high-frequency characteristics with a relatively stable energy distribution. Therefore, regardless of whether it is internal or external leakage, the more stable the corresponding frequency change, the higher the reliability of the corresponding frequency. That is, for each frequency, the smaller the difference between its corresponding frequency change value and the next frequency change value, the more stable the instantaneous energy change at that frequency, the higher its reference value, and the greater the frequency stability weight.

[0084] In one specific implementation of this invention, the process of obtaining the frequency stability weight is expressed by the formula: ;in, For the first The location is at frequency Frequency-stable weights; It is a linear normalization function; For the first The location is at frequency The corresponding amplitude change value, when the frequency If the previous frequency does not exist, then the frequency will be... The amplitude change value is set to 0; For the first The location is at frequency The frequency change value at the next frequency, when the frequency If no next frequency exists, the mean amplitude of the frequency changes at all other sampling times is compared with the frequency. The frequency change value of the next frequency is calculated, which will not be elaborated further here.

[0085] The product of the negative correlation mapping value of each frequency value and the corresponding frequency amplitude determines the corresponding internal leakage frequency characteristic value. The product of the frequency stability weight and the internal leakage frequency characteristic value is normalized to determine the internal leakage correlation of each location at each frequency. Since internal leakage is a low-frequency phenomenon, the smaller the frequency value, the more attention needs to be paid to the corresponding frequency amplitude. Furthermore, the linear and stable energy decay characteristic of internal leakage will cause the frequency amplitude of low frequencies exhibiting internal leakage characteristics to show a higher value; therefore, the larger the frequency amplitude, the greater the attention required. In addition, the frequency stability weight characterizes the reliability of each frequency. Therefore, the frequency value, frequency amplitude, and corresponding frequency stability weight of each frequency are comprehensively combined to characterize the internal leakage correlation of each location at each frequency, so that the greater the internal leakage correlation, the greater the attention required for the corresponding frequency.

[0086] In one specific implementation of this invention, the process of obtaining the correlation of internal leakage is expressed by the following formula: ;in, For the first The location is at frequency Internal leakage correlation; For frequency The frequency value; For the first The location is at frequency The frequency amplitude below; For the first The location is at frequency The characteristic value of internal leakage frequency under the following conditions; For the first The location is at frequency Frequency-stable weights.

[0087] Further, at each frequency, the frequency amplitudes of all locations along the pipe wall conduction direction on the corresponding vibration spectrum are sequentially arranged and then a straight line is fitted to determine the internal leakage characteristic fitting line corresponding to each frequency; the internal leakage characteristic residual sum corresponding to the internal leakage characteristic fitting line is obtained by the deviation between the frequency amplitude corresponding to each location and the internal leakage characteristic fitting line and the corresponding internal leakage correlation; preferably, in some possible implementations of the embodiments of the present invention, the process of obtaining the internal leakage characteristic residual sum includes:

[0088] The difference between the frequency amplitude corresponding to each frequency on the vibration spectrum of each location and the corresponding fitted frequency amplitude on the internal leakage characteristic fitting line is used to determine the corresponding internal leakage fitting deviation value; the product of the internal leakage correlation at each frequency and the internal leakage fitting deviation value is used to determine the local error value of internal leakage at each location at each frequency; and the sum of the local error values ​​of internal leakage at each frequency for all locations is used to determine the internal leakage characteristic residual of the internal leakage characteristic fitting line corresponding to each frequency.

[0089] Since a higher correlation between frequencies and internal leakage frequencies necessitates greater attention to those frequencies, when calculating the internal leakage feature residuals during the fitting of the internal leakage feature line, frequencies with higher internal leakage correlation require higher weighting in the calculation to ensure a more accurate internal leakage feature residual sum. Similar to the fitting principle of the optimal leakage fitting curve, the internal leakage feature fitting line is the line that minimizes the internal leakage feature residual sum when using the least squares method for linear fitting.

[0090] The spatial distribution of internal and external leakage is essentially a manifestation of the attenuation of vibrational energy with propagation distance, and the optimal linear characteristic parameter quantitatively describes the rate of this attenuation. When the time-domain signal at each location is converted to the frequency domain, the spatial distribution of the amplitude of individual frequency components is evaluated. If the amplitude of that frequency also exhibits strictly linear attenuation, and its attenuation slope is equal to the optimal slope attenuation in the spatial domain, it proves that the attenuation mechanism of that frequency is completely consistent with the attenuation mechanism dominated by internal leakage. Frequency satisfying this condition can be highly confidently identified as the characteristic frequency of internal leakage. Therefore, based on this characteristic, and considering the similarity between the slope of the internal leakage characteristic fitting line and the optimal linear characteristic parameter of internal leakage, as well as the amplitude distribution on the internal leakage characteristic fitting line, the amplitude of the internal leakage frequency at each frequency at each location can be determined.

[0091] The process of obtaining the internal leakage frequency amplitude includes: determining the fitted frequency amplitude of each location at each frequency based on the amplitude corresponding to each location on the fitted line of internal leakage characteristics; and determining the internal leakage reference weight for each frequency by negatively mapping the difference between the slope of the fitted line of internal leakage characteristics corresponding to each frequency and the optimal linear characteristic parameter of internal leakage.

[0092] For each frequency, the smaller the difference between the slope of the corresponding internal leakage characteristic fitting line and the optimal linear characteristic parameter of the internal leakage (i.e., the larger the internal leakage reference weight), the more the frequency conforms to the energy attenuation characteristics in the spatial domain. Therefore, the higher the reliability of the corresponding frequency in the dimension of the final frequency performance of the internal leakage. Thus, the product of the fitted frequency amplitude at each location on the internal leakage characteristic fitting line and the internal leakage reference weight is used to determine the internal leakage frequency amplitude at each location at each frequency. Finally, based on the internal leakage frequency amplitude at all frequencies, the final internal leakage spectrum of each location is determined. Time-frequency conversion is then performed on the final internal leakage spectrum of each location to determine the internal leakage signal separation map. The method for time-frequency conversion of the final internal leakage spectrum uses the inverse Fourier transform method, which will not be elaborated further here.

[0093] In one specific implementation of this invention, the process of obtaining the internal leakage frequency amplitude is expressed by the following formula: ;in, For the first The location is at frequency The amplitude of internal leakage frequency; For the first The location is at frequency The fitted frequency amplitude; It is an exponential function with the natural constant as its base; It is the absolute value symbol; For frequency The slope of the fitted straight line for the internal leakage characteristics; The optimal linear characteristic parameter for internal leakage; For frequency Internal leakage reference weight.

[0094] Furthermore, based on the principle of the internal leakage signal separation diagram, the external leakage signal separation diagram is determined according to the high-frequency amplitude concentration stability in the vibration spectrum diagram, the optimal linear characteristic parameters, and the regularity of frequency values ​​at all locations in the pipe wall conduction direction in the external leakage.

[0095] Preferably, in some possible implementations of the embodiments of the present invention, the process of obtaining the external leakage signal separation map includes:

[0096] Unlike internal leakage, which exhibits a linear and stable decay characteristic with increasing frequency, external leakage is characterized by high amplitude and stability at high frequencies. Therefore, the calculation of external leakage correlation also requires the incorporation of frequency stability weights that characterize the stable change characteristics. Unlike internal leakage correlation calculation, which requires negative correlation mapping based on the low-frequency behavior of internal leakage, external leakage spectral energy is typically highly concentrated in the high-frequency bandwidth. Therefore, the frequency values ​​here need to be positively correlated and fused. Thus, in this embodiment of the invention, the product of the normalized frequency value and the corresponding frequency amplitude of each frequency in the vibration spectrum is used to determine the corresponding external leakage frequency characteristic value. The product of the frequency stability weight and the external leakage frequency characteristic value is then normalized to determine the external leakage correlation at each location and at each frequency. It should be noted that, apart from the different frequency value processing, the other calculation processes and principles are the same as those for internal leakage correlation calculation, and the formulas and principles will not be further elaborated here.

[0097] Furthermore, at each frequency, the frequency amplitudes of all locations along the pipe wall conduction direction on the corresponding vibration spectrum are arranged sequentially and then a straight line is fitted to determine the fitting straight line of the external leakage characteristics corresponding to each frequency; based on the principle of obtaining the internal leakage signal separation map, the external leakage signal separation map is determined according to the external leakage characteristic fitting straight line and the external leakage correlation.

[0098] In one specific implementation of this invention, the residual sum of internal leakage characteristics corresponding to the internal leakage characteristic fitting line is obtained by the deviation between the frequency amplitude corresponding to each location and the internal leakage characteristic fitting line, as well as the corresponding internal leakage correlation. Specifically: the difference between the frequency amplitude corresponding to each frequency on the vibration spectrum of each location and the fitting frequency amplitude corresponding to the external leakage characteristic fitting line is used to determine the corresponding external leakage fitting deviation value; the external leakage local error value at each location at each frequency is determined based on the product between the external leakage correlation at each frequency and the external leakage fitting deviation value; and the external leakage characteristic residual sum of the external leakage characteristic fitting line corresponding to each frequency is determined based on the cumulative value of the external leakage local error values ​​at each frequency for all locations.

[0099] Further, based on the amplitude corresponding to each location on the external leakage characteristic fitting line, the fitted frequency amplitude at each location at each frequency is determined. The difference between the slope of the external leakage characteristic fitting line corresponding to each frequency and the optimal linear characteristic parameter of the external leakage is negatively correlated to determine the external leakage reference weight at each frequency. The product of the fitted frequency amplitude corresponding to each location on the external leakage characteristic fitting line and the external leakage reference weight is used to determine the external leakage frequency amplitude at each location at each frequency. Based on the external leakage frequency amplitude at all frequencies for each location, the final external leakage spectrum diagram for each location is determined. Time-frequency conversion is performed based on the final external leakage spectrum diagrams for each location to determine the external leakage signal separation diagram. It should be noted that since the principle for obtaining the external leakage signal separation diagram is the same as that for obtaining the internal leakage signal separation diagram, its formulas and related explanations will not be further elaborated.

[0100] Step S104: Perform synchronous monitoring of internal and external leakage of the vent valve based on the internal leakage signal separation diagram and the external leakage signal separation diagram.

[0101] The internal leakage signal separation diagram represents the final separated internal leakage signal, while the external leakage signal separation diagram represents the final separated external leakage signal. Finally, based on the determined internal and external leakage signal separation diagrams, more accurate synchronous monitoring of internal and external leakage of the relief valve is performed. For the internal leakage signal separation diagram, if the internal leakage is characterized by a continuous increase in signal strength and an expansion of the spectral components into higher frequencies, it indicates that the leakage is intensifying. If the external leakage exhibits short-term, sharp fluctuations in the signal, it often suggests unstable injection pressure or a change in the leakage orifice diameter; these will not be elaborated further here.

[0102] In summary, a method for synchronous monitoring of internal and external leakage of a venting valve based on a fiber optic array first determines the optimal linear characteristic parameters in the time domain by utilizing the linear relationship of leakage based on the continuity characteristics of time-domain signals at various locations. Then, in the frequency domain, based on the frequency attenuation stability characteristics of internal leakage and the high-frequency concentrated stability characteristics of external leakage, combined with the optimal linear characteristic parameters and the frequency law in the spatial domain, more accurate internal and external leakage signal separation maps are obtained. Thus, more accurate synchronous monitoring of internal and external leakage of the venting valve is achieved based on the internal and external leakage signal separation maps.

[0103] This application also provides a fiber optic array-based system for synchronous monitoring of internal and external leakage in a vent valve. Please refer to [link / reference]. Figure 2 The diagram shows a structural diagram of a fiber optic array-based synchronous monitoring system for internal and external leakage of a vent valve, which is provided in an embodiment of the present invention. The system includes: a data acquisition and preprocessing module 201, a first determination module 202, a second determination module 203, and a leakage monitoring module 204.

[0104] The data acquisition and preprocessing module 201 is used to acquire the vibration time-domain map of each location in the spatial domain at the starting point of the fiber array using a DAS demodulator; and to perform time-frequency conversion on the vibration time-domain map to determine the corresponding vibration spectrum map.

[0105] The first determining module 202 is used to determine the corresponding optimal linear characteristic parameters on the vibration time domain diagram based on the stability of the change of vibration signal values ​​and the linearity of vibration signal values ​​at all locations in the pipe wall transmission direction in terms of internal and external leakage.

[0106] The second determining module 203 is used to determine the internal leakage signal separation diagram based on the stability of low-frequency amplitude attenuation in the vibration spectrum diagram, the optimal linear characteristic parameter, and the conformity of frequency values ​​at all locations in the pipe wall conduction direction with the internal leakage pattern; and to determine the external leakage signal separation diagram based on the stability of high-frequency amplitude concentration in the vibration spectrum diagram, the optimal linear characteristic parameter, and the conformity of frequency values ​​at all locations in the pipe wall conduction direction with the external leakage pattern.

[0107] Leakage monitoring module 204 is used to simultaneously monitor internal and external leakage of the vent valve based on the internal leakage signal separation diagram and the external leakage signal separation diagram.

[0108] It should be noted that the system provided in the above embodiments is only an example of the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the computer device can be divided into different functional modules to complete all or part of the functions described above. In addition, the fiber optic array-based system for synchronous monitoring of internal and external leakage of a vent valve and the fiber optic array-based method for synchronous monitoring of internal and external leakage of a vent valve belong to the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0109] This application also provides a computer device; please refer to [link / reference]. Figure 3 The diagram illustrates a computer device structure according to an embodiment of the present invention. The computer device includes a memory 301, a processor 302, and a computer program 303 stored in the memory 301 and running on the processor 302. When the processor 302 executes the computer program 303, the computer device can execute any of the aforementioned fiber optic array-based methods for synchronous monitoring of internal and external leakage of a vent valve.

[0110] This application also provides a computer program product that, when run on a computer device, enables the computer device to execute any of the aforementioned fiber optic array-based methods for synchronous monitoring of internal and external leakage of a vent valve.

[0111] This application also provides a computer-readable storage medium storing computer program code. When the computer program code is run on a computer device, the computer device can execute any of the aforementioned fiber optic array-based methods for synchronous monitoring of internal and external leakage of a vent valve.

[0112] In the embodiments provided in this application, it should be understood that the computer device, computer program product and computer-readable storage medium provided are all used to perform the corresponding methods provided above, and therefore the beneficial effects they can achieve can be referred to the beneficial effects of the methods provided above, which will not be repeated here.

[0113] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0114] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array, characterized in that, The method includes: Vibration time-domain images of each location in the spatial domain are acquired at the starting point of the fiber optic array using a DAS demodulator; the vibration time-domain images are then converted to time-frequency data to determine the corresponding vibration spectrum. On the vibration time-domain diagram, based on the stability of the vibration signal value change and the linearity of the vibration signal values ​​at all locations along the pipe wall conduction direction in terms of internal and external leakage, the corresponding optimal linear characteristic parameters are determined. Based on the stable attenuation of low-frequency amplitude in the vibration spectrum, the optimal linear characteristic parameter, and the consistency of frequency values ​​at all locations along the pipe wall conduction direction with the internal leakage pattern, an internal leakage signal separation diagram is determined; based on the stable concentration of high-frequency amplitude in the vibration spectrum, the optimal linear characteristic parameter, and the consistency of frequency values ​​at all locations along the pipe wall conduction direction with the external leakage pattern, an external leakage signal separation diagram is determined. Synchronous monitoring of internal and external leakage of the vent valve is performed based on the internal leakage signal separation diagram and the external leakage signal separation diagram.

2. The method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array according to claim 1, characterized in that, The process of obtaining the optimal linear feature parameters includes: On the vibration time-domain diagram, the instantaneous stationary weight of each location at each sampling time is determined based on the deviation of vibration signal value changes between adjacent sampling times; at each sampling time, the vibration signal values ​​of all locations are arranged sequentially along the pipe wall conduction direction to determine the vibration signal value sequence of each sampling time. A rectangular coordinate system is constructed with the location along the direction of transmission along the pipe wall as the horizontal axis and the vibration signal value as the vertical axis; the data points corresponding to each location in the vibration signal value sequence on the rectangular coordinate system are obtained; The optimal leakage fitting curve is determined by fitting the objective function using the least squares method based on all data points in the rectangular coordinate system. The objective function is obtained by superimposing a linear function and an external leakage reference function. The external leakage reference function is a piecewise function composed of two line segments that form an isosceles triangle with the x-axis. The internal leakage residual corresponding to the optimal leakage fitting curve is obtained by the deviation between the vibration signal value at each location and the optimal leakage fitting curve, as well as the corresponding instantaneous stationary weight. Based on the slope distribution of the optimal leakage fitting curve at each sampling time, the corresponding optimal linear characteristic parameters are determined.

3. The method for synchronous monitoring of internal and external leakage of a venting valve based on a fiber optic array according to claim 2, characterized in that, The process of obtaining the instantaneous stationary weights includes: On the vibration time-domain graph, the local vibration change value at each sampling time is determined based on the difference between the vibration signal value at each location at each sampling time and the vibration signal value at the previous sampling time; the difference between the local vibration change value at each sampling time and the local vibration change value at the next sampling time is negatively correlated and mapped to determine the instantaneous stationary weight of each location at each sampling time.

4. The method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array according to claim 2, characterized in that, The process of determining the corresponding optimal linear characteristic parameters based on the slope distribution changes of the optimal leakage fitting curve at each sampling time includes: The slope value of the linear function that constitutes the optimal leakage fitting curve at each sampling time is used as the internal leakage slope parameter at each sampling time. The difference between the internal leakage slope parameter at each sampling time and the internal leakage slope parameter at the previous sampling time is negatively correlated and normalized to determine the contribution weight of the internal leakage parameter at each sampling time. The contribution value of the corresponding internal leakage parameter is determined by multiplying the internal leakage slope parameter at each sampling time with the contribution weight of the internal leakage parameter. The optimal linear characteristic parameter corresponding to the internal leakage is determined by accumulating the contribution values ​​of the internal leakage parameters at all sampling times. The maximum slope of the two line segments corresponding to the external leakage reference function that constitute the optimal leakage fitting curve at each sampling time is taken as the external leakage slope parameter at each sampling time. Based on the principle of obtaining the optimal linear characteristic parameter corresponding to internal leakage, the optimal linear characteristic parameter corresponding to external leakage is determined based on the external leakage slope parameter.

5. The method for synchronous monitoring of internal and external leakage of a venting valve based on a fiber optic array according to claim 2, characterized in that, The process of obtaining the sum of internal leakage residuals includes: At each sampling time, the difference between the vibration signal value corresponding to each location and the corresponding fitted value on the optimal leakage fitting curve is taken as the initial residual value for each location; the product between the initial residual value for each location and the corresponding instantaneous stationary weight is used to determine the corresponding weighted residual value; the sum of the weighted residual values ​​for all locations at each sampling time is used to determine the corresponding internal leakage residual sum.

6. The method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array according to claim 2, characterized in that, The process of obtaining the internal leakage signal separation map includes: Based on the frequency stability of the vibration spectrum, determine the frequency stability weight for each frequency; The product of the negative correlation mapping value of each frequency value and the corresponding frequency amplitude is used to determine the corresponding internal leakage frequency characteristic value; the product of the frequency stability weight and the internal leakage frequency characteristic value is normalized to determine the internal leakage correlation of each location at each frequency. At each frequency, the frequency amplitudes of all locations along the pipe wall conduction direction are sequentially arranged on the corresponding vibration spectrum diagram and then a straight line is fitted to determine the internal leakage characteristic fitting line corresponding to each frequency; the internal leakage characteristic residual corresponding to the internal leakage characteristic fitting line is obtained by the deviation between the frequency amplitude corresponding to each location and the internal leakage characteristic fitting line and the corresponding internal leakage correlation. Based on the similarity between the slope of the fitted line of internal leakage characteristics and the optimal linear characteristic parameters of internal leakage, as well as the amplitude distribution on the fitted line of internal leakage characteristics, the amplitude of internal leakage frequency at each location at each frequency is determined. Based on the internal leakage frequency amplitude at all frequencies at each location, determine the final internal leakage spectrum diagram for each location; perform time-frequency conversion based on the final internal leakage spectrum diagrams for each location to determine the internal leakage signal separation diagram.

7. The method for synchronous monitoring of internal and external leakage of a venting valve based on a fiber optic array according to claim 6, characterized in that, The process of obtaining the frequency stabilization weights includes: On the vibration spectrum, the difference between the frequency amplitude of each frequency and the frequency amplitude of the previous frequency is taken as the amplitude change value of each frequency; the difference between the amplitude change value of each frequency and the frequency change value of the next frequency is negatively correlated and mapped to determine the frequency stability weight of each frequency.

8. The method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array according to claim 6, characterized in that, The process of obtaining the sum of the residuals of the internal leakage characteristics includes: The difference between the frequency amplitude corresponding to each frequency on the vibration spectrum of each location and the corresponding fitted frequency amplitude on the internal leakage characteristic fitting line is used to determine the corresponding internal leakage fitting deviation value. The internal leakage local error value at each location at each frequency is determined by multiplying the internal leakage correlation at each frequency with the internal leakage fitting deviation value; the internal leakage characteristic residual of the internal leakage characteristic fitting line corresponding to each frequency is determined by summing the internal leakage local error values ​​at all locations at each frequency.

9. The method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array according to claim 6, characterized in that, The process of obtaining the internal leakage frequency amplitude includes: Based on the amplitude corresponding to each location on the internal leakage feature fitting line, determine the fitting frequency amplitude at each location at each frequency; perform a negative correlation mapping between the slope of the internal leakage feature fitting line corresponding to each frequency and the difference between the optimal linear feature parameters of the internal leakage, and determine the internal leakage reference weight at each frequency; multiply the fitting frequency amplitude corresponding to each location on the internal leakage feature fitting line and the internal leakage reference weight to determine the internal leakage frequency amplitude at each location at each frequency.

10. The method for synchronous monitoring of internal and external leakage of a vent valve based on a fiber optic array according to claim 6, characterized in that, The process of obtaining the external leakage signal separation map includes: On the vibration spectrum, the product of the normalized value of each frequency value and the corresponding frequency amplitude is used to determine the corresponding external leakage frequency characteristic value; the product of the frequency stability weight and the external leakage frequency characteristic value is normalized to determine the external leakage correlation at each location at each frequency. At each frequency, the frequency amplitudes of all locations along the pipe wall conduction direction on the corresponding vibration spectrum are arranged sequentially and then a straight line is fitted to determine the fitting straight line of the external leakage characteristic corresponding to each frequency. Based on the principle of obtaining the internal leakage signal separation map, the external leakage signal separation map is determined according to the fitting line of the external leakage characteristics and the external leakage correlation.

Images