A method, system, electronic device and storage medium for strain and temperature decoupling of a multicore fiber using grating demodulation

Abstract

The application provides a kind of grating demodulation multi-core optical fiber strain and temperature decoupling method, system, electronic equipment and storage medium, it relates to optical fiber sensing technical field, the application obtains the lowest wavelength data of the spectrum of the fiber core on both sides of the air layer of multi-core optical fiber, simultaneously record the spot position data formed by the second-order dispersion of diffraction grating. Utilize the secondary light splitting of composite light by diffraction grating, generate independent spectral data and block two-core coupling through air layer. Build a double-task analysis network, get strain wavelength shift through strain branch, get temperature wavelength correction through temperature branch. Combine related data to adjust network weight to generate strain demodulation value of temperature decoupling, convert to standardized signal transmission to monitoring system, reconstruct axial strain dynamic distribution map and display temperature compensation curve synchronously, can realize multi-core optical fiber strain and temperature accurate decoupling, dynamically obtain strain information and synchronously show distribution and compensation state.

Description

Technical Field

[0001] This application relates to the field of fiber optic sensing technology, and in particular to a method, system, electronic device, and storage medium for decoupling strain and temperature in a multi-core fiber optic cable with grating demodulation. Background Technology

[0002] In the monitoring of high-temperature and high-pressure pipeline operation, it is necessary to grasp the strain state of the pipeline surface in real time to predict structural safety, and at the same time, it is necessary to accurately obtain the internal fluid temperature to ensure process stability. Furthermore, the measurement process must avoid contact with the pipeline surface to prevent damage to the sealing performance or interference from extreme environments. This has created an urgent need for non-contact, high-precision strain and temperature decoupled measurement.

[0003] Currently, the common solution for this requirement is to use a combination of single-core fiber optic grating sensor and infrared thermometer. The single-core fiber optic grating senses the strain on the pipe surface, while the infrared thermometer simultaneously collects the ambient temperature near the pipe. The temperature effect is then roughly corrected using a preset empirical formula.

[0004] However, this scheme has obvious drawbacks: single-core fiber gratings are susceptible to interference from temperature and strain, and it is difficult to achieve accurate decoupling between the two using only empirical formulas; infrared thermometers are greatly affected by environmental radiation, dust and other factors, resulting in high measurement errors, and cannot directly reflect the true temperature of the fluid inside the pipeline, leading to insufficient accuracy of strain measurement results, which makes it difficult to meet the precision monitoring needs of high-temperature and high-pressure pipelines. Summary of the Invention

[0005] The purpose of this application is to provide a method, system, electronic device, and storage medium for decoupling strain and temperature in a multi-core optical fiber using grating demodulation, in order to solve the problem of insufficient accuracy of strain measurement results in the prior art.

[0006] To address the aforementioned technical problems, in a first aspect, this application provides a method for decoupling strain and temperature in a multi-core optical fiber using grating demodulation, comprising:

[0007] Obtain the lowest wavelength data of the fiber core spectrum on both sides of the air layer of the multi-core optical fiber, and simultaneously record the spot position data formed by the second-order dispersion of the diffraction grating;

[0008] The composite light output from the multi-core optical fiber is split a second time using a diffraction grating, and the spectra of the two fiber cores are projected onto non-overlapping regions in a photoelectric array to generate independent spectral data. Based on the independent spectral data, the coupling between the two optical paths is blocked by an air layer to enhance the strain sensitivity characteristics.

[0009] The dual-task analysis network of the parallel structure is constructed, the continuous waveform comparison is performed on the strain analysis branch of the dual-task analysis network based on the minimum wavelength data, the strain wavelength offset is obtained, the dynamic trajectory tracking is performed on the temperature compensation branch of the dual-task analysis network according to the spot position data, and the temperature wavelength correction amount is obtained;

[0010] The shared layer weight of the dual-task analysis network is dynamically adjusted based on the independent spectrum data, the time sequence data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction amount, and the strain demodulation value decoupled from temperature is generated;

[0011] The standardized strain characteristic signal is generated through photoelectric signal conversion based on the strain demodulation value decoupled from temperature, the characteristic signal is transmitted to a monitoring system, the axial strain dynamic distribution map of the multi-core optical fiber is reconstructed, and the temperature compensation state curve is synchronously displayed.

[0012] Optionally, the dual-task analysis network of the parallel structure is constructed, the continuous waveform comparison is performed on the strain analysis branch of the dual-task analysis network based on the minimum wavelength data, the strain wavelength offset is obtained, the dynamic trajectory tracking is performed on the temperature compensation branch of the dual-task analysis network according to the spot position data, and the temperature wavelength correction amount is obtained, including:

[0013] The dual-task analysis network with parallel processing paths is built, the network includes two parallel processing branches of the strain analysis branch and the temperature compensation branch, and the two branches share part of initial processing units;

[0014] The waveform features corresponding to the minimum wavelength data are extracted through the strain analysis branch, the waveform features at the current moment are continuously compared with the waveform features at the previous moment, the difference between the two waveforms is recorded, and the strain wavelength offset is obtained;

[0015] The position change trajectory of the spot at different moments is tracked through the temperature compensation branch, the position points on the position change trajectory are continuously recorded, the moving amplitude and direction of the position points are analyzed, and the temperature wavelength correction amount is obtained.

[0016] Optionally, the waveform features corresponding to the minimum wavelength data are extracted through the strain analysis branch, the waveform features at the current moment are continuously compared with the waveform features at the previous moment, the difference between the two waveforms is recorded, and the strain wavelength offset is obtained, including:

[0017] The minimum wavelength data is divided into data segments according to a preset time interval, each data segment corresponds to the minimum wavelength data at a moment, and the minimum wavelength data at each moment is sequentially input into the strain analysis branch;

[0018] Based on the input minimum wavelength data, the strain analysis branch identifies the vertex position, the inflection point position and the fluctuation interval range in the waveform corresponding to each moment data as the waveform characteristics of each moment;

[0019] According to the waveform characteristics of the current moment and the waveform characteristics of the previous moment, the difference value corresponding to the vertex position and the difference value of the inflection point position are calculated, the fluctuation interval ranges of the current moment and the previous moment are compared, and the change amount of the fluctuation interval boundary is determined;

[0020] The difference value of the vertex position, the difference value of the inflection point position and the change amount of the fluctuation interval boundary are comprehensively calculated to record the difference between the two waveforms and obtain the strain wavelength offset.

[0021] Optionally, through the temperature compensation branch, the position change trajectory of the light spot at different moments is tracked, the position points on the position change trajectory are continuously recorded, the moving amplitude and direction of the position points are analyzed, and the temperature wavelength correction amount is obtained, including:

[0022] Collecting light spot position data at different moments at preset time intervals, and sequentially inputting the light spot position data into the temperature compensation branch;

[0023] Through the temperature compensation branch, the spatial position of the light spot at each moment is identified and marked as a position point, and the position points at different moments are connected in time sequence to form a position change trajectory of the light spot;

[0024] Selecting the position points at adjacent moments in the position change trajectory, calculating the straight line distance between the position points at adjacent moments as the moving amplitude, and determining the spatial offset direction of the position point at the next moment relative to the position point at the previous moment as the moving direction;

[0025] Recording the moving amplitude and the moving direction in the continuous multiple time periods, and associating and calculating the moving amplitude and the offset amount corresponding to the moving direction to obtain the temperature wavelength correction amount.

[0026] Optionally, based on the independent spectral data, the time sequence data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction amount are combined to dynamically adjust the shared layer weight of the dual-task analysis network, and the strain demodulation value decoupled from temperature is generated, including:

[0027] Obtaining the generated independent spectral data, collecting the time sequence data formed by the strain wavelength offset changing with time, and the amplitude fluctuation data of the temperature wavelength correction amount;

[0028] inputting the independent spectrum data, the time series data and the amplitude fluctuation data into a shared layer of the dual-task analysis network simultaneously, and analyzing the light signal characteristics of the two side cores in the independent spectrum data through the shared layer;

[0029] Based on the light signal characteristics, the change trend of the strain wavelength offset in the time series data and the fluctuation range of the temperature wavelength correction in the amplitude fluctuation data, the action intensity of each processing unit in the shared layer is dynamically adjusted;

[0030] By enhancing the shared layer weight of the strain-related signal characteristics in the light signal characteristics and weakening the shared layer weight of the temperature-related signal characteristics, an adjusted dual-task analysis network is obtained.

[0031] Through the adjusted dual-task analysis network, the input data is processed to generate strain demodulation values that eliminate the influence of temperature, i.e. temperature-decoupled strain demodulation values.

[0032] Optionally, a diffraction grating is used to perform secondary light splitting on the composite light output by the multicore optical fiber, and the two side core spectrums are projected into non-overlapping areas of a photoelectric array to generate independent spectrum data. Based on the independent spectrum data, the two-core light path coupling is blocked by an air layer to enhance the strain sensitivity characteristics, including:

[0033] The composite light output by the multicore optical fiber is input into the diffraction grating, and the diffraction grating is used to perform first light splitting to obtain preliminary separated signals of different wavelengths. The preliminary separated signals are then subjected to second light splitting by the diffraction grating to obtain light signals of different wavelengths with expanded separation degree.

[0034] A photoelectric array is arranged at the light signal exit of the diffraction grating, and the photoelectric array is divided into two independent areas that do not overlap. The light signals subjected to secondary light splitting are projected into the two independent areas, respectively.

[0035] According to the projection of the light signals in the respective corresponding photoelectric array areas, respective spectral images are formed. The spectral images are converted into electrical signals by the photoelectric array to generate independent spectrum data of the two side cores, respectively. The independent spectrum data reflects the changes of the light signals of the two side cores affected by strain.

[0036] An air layer is arranged between the two side cores of the multicore optical fiber, and the air layer is used to prevent the light signals of the two side cores from coupling with each other to enhance the strain sensitivity characteristics.

[0037] Optionally, based on the temperature-decoupled strain demodulation values, a standardized strain characteristic signal is generated through photoelectric signal conversion. The characteristic signal is transmitted to a monitoring system to reconstruct a dynamic distribution map of the axial strain of the multicore optical fiber and simultaneously display a temperature compensation state curve, including:

[0038] inputting the strain demodulation value decoupled from the temperature to a photoelectric conversion device, and converting a light signal corresponding to the strain demodulation value into an electric signal through the photoelectric conversion device;

[0039] performing standardization processing on the converted electric signal to make the amplitude and range of the signal within a preset standard interval, and generating a standardized strain characteristic signal;

[0040] sending the strain characteristic signal to a monitoring system through a data transmission line, and arranging the strain characteristic signals corresponding to different positions in an axial direction according to the axial position information of the multi-core optical fiber to form a dynamic distribution diagram of the axial strain of the multi-core optical fiber after the monitoring system receives the signal;

[0041] extracting temperature wavelength correction data through the monitoring system, presenting the change of the temperature wavelength correction data with time in a curve form, and synchronously displaying the dynamic distribution diagram and the temperature compensation state curve on a monitoring interface.

[0042] In a second aspect, the application provides a multi-core optical fiber strain and temperature decoupling system based on grating demodulation, comprising:

[0043] an acquisition module configured to acquire the lowest wavelength data of the fiber core spectra on both sides of the air layer of the multi-core optical fiber, and record the spot position data formed by the second-order dispersion of the diffraction grating;

[0044] a blocking module configured to use the diffraction grating to perform secondary light splitting on the composite light output by the multi-core optical fiber, project the fiber core spectra on both sides into non-overlapping areas in the photoelectric array respectively, generate independent spectrum data, and block the coupling of the two-core light paths through the air layer based on the independent spectrum data to enhance the strain sensitive characteristics;

[0045] a construction module configured to construct a double-task analysis network with a parallel structure, perform continuous waveform comparison through a strain analysis branch of the double-task analysis network based on the lowest wavelength data, obtain a strain wavelength offset, perform dynamic trajectory tracking through a temperature compensation branch of the double-task analysis network based on the spot position data, and obtain a temperature wavelength correction amount;

[0046] an adjustment module configured to dynamically adjust the shared layer weight of the double-task analysis network based on the independent spectrum data, the time series data of the strain wavelength offset, and the amplitude fluctuation of the temperature wavelength correction amount, and generate a strain demodulation value decoupled from the temperature;

[0047] a reconstruction module configured to generate a standardized strain characteristic signal through photoelectric signal conversion based on the strain demodulation value decoupled from the temperature, transmit the characteristic signal to a monitoring system, reconstruct a dynamic distribution diagram of the axial strain of the multi-core optical fiber, and synchronously display a temperature compensation state curve.

[0048] In a third aspect, the present application provides an electronic device, comprising:

[0049] a memory for storing a computer program;

[0050] a processor for executing the computer program to implement the steps of the grating demodulation multi-core fiber strain and temperature decoupling method according to the first aspect.

[0051] In a fourth aspect, the present application provides a computer readable storage medium, wherein the computer readable storage medium stores a computer program, and the computer program is executable by a processor to implement the steps of the grating demodulation multi-core fiber strain and temperature decoupling method according to the first aspect.

[0052] The grating demodulation multi-core fiber strain and temperature decoupling method provided by the present application can provide basic data support for subsequent strain and temperature decoupling analysis by obtaining the minimum wavelength data of the fiber core spectrum on both sides of the multi-core fiber air layer and recording the spot position data formed by the second-order dispersion of the diffraction grating. The independent spectrum data can be generated by using the diffraction grating to perform secondary spectroscopy on the composite light output by the multi-core fiber and projecting the spectrum of the two fiber cores into non-overlapping areas in the photoelectric array. The strain and temperature related parameters can be extracted separately by blocking the coupling of the two-core light path based on the independent spectrum data to enhance the strain sensitive characteristics, which can reduce the interference of the light path and improve the recognizability of the strain signal. The strain and temperature related parameters can be extracted separately by constructing a double-task analysis network with a parallel structure, obtaining the strain wavelength shift from the strain analysis branch based on the minimum wavelength data, and obtaining the temperature wavelength correction from the temperature compensation branch based on the spot position data. The strain measurement interference caused by temperature can be eliminated by dynamically adjusting the shared layer weight of the double-task analysis network based on the independent spectrum data, combining the time series data of the strain wavelength shift and the amplitude fluctuation of the temperature wavelength correction, and generating the strain demodulation value decoupled from temperature. The accurate strain result can be obtained. The strain state of the pipeline and the temperature compensation effect can be intuitively presented by generating the standardized strain characteristic signal from the strain demodulation value decoupled from temperature through photoelectric signal conversion and transmitting it to the monitoring system, reconstructing the axial strain dynamic distribution map, and synchronously displaying the temperature compensation state curve, which facilitates real-time monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0053] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0054] Figure 1 A flowchart of a grating demodulation multi-core optical fiber strain and temperature decoupling method provided for an embodiment of the present application is shown in FIG. 1.

[0055] Figure 2 A specific implementation diagram of a grating demodulation multi-core optical fiber strain and temperature decoupling method provided for an embodiment of the present application is shown in FIG. 2.

[0056] Figure 3 A scene diagram of a grating demodulation multi-core optical fiber strain and temperature decoupling method provided for an embodiment of the present application is shown in FIG. 3.

[0057] Figure 4 A structural diagram of a grating demodulation multi-core optical fiber strain and temperature decoupling system provided for an embodiment of the present application is shown in FIG. 4. DETAILED DESCRIPTION

[0058] In high-temperature and high-pressure pipeline monitoring, the existing single-core fiber grating combined with an infrared temperature meter has obvious limitations: on the one hand, it is difficult for a single-core fiber grating to distinguish the influence of temperature and strain, and only relying on empirical formula correction cannot achieve accurate separation of the two, resulting in easy "deviation" of strain measurement; on the other hand, the infrared temperature meter is greatly disturbed by environmental dust, radiation, etc., and the measured temperature is not accurate, and it cannot directly reflect the real temperature of the fluid inside the pipeline, ultimately making the strain result unreliable and difficult to guarantee the safety monitoring needs of the pipeline. The core of these problems lies in the fact that the traditional scheme cannot effectively isolate the mutual interference of temperature and strain, and also lacks a direct and stable temperature measurement method.

[0059] To solve the above problems, the present application provides a grating demodulation multi-core optical fiber strain and temperature decoupling method, which realizes accurate monitoring through special optical signal processing and analysis strategies. The method first acquires the optical signal characteristics and spot position data of the two sides of the multi-core optical fiber, uses a diffraction grating to separate the two sides of the optical signal and generate independent data, and at the same time reduces signal interference through an air layer; then with the help of a parallel double-task analysis network, wavelength changes related to strain and spot trajectory changes related to temperature are extracted respectively, and a strain result eliminating the influence of temperature is generated by combining a dynamically adjusted analysis strategy, and finally the strain distribution and temperature compensation state are intuitively displayed through a monitoring system. This scheme solves the cross interference problem of temperature and strain through the signal separation design of multi-core optical fiber, directly reflects the temperature change through the spot position data to avoid environmental interference, and fundamentally improves the accuracy of strain measurement, meeting the needs of high-temperature and high-pressure pipeline precision monitoring.

[0060] In order for those skilled in the art to better understand the present application, the present application will be further described in detail below in conjunction with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0061] The core of the present application is to provide a grating demodulation multi-core optical fiber strain and temperature decoupling method, and a specific embodiment thereof is shown in the flowchart Figure 1 The method comprises:

[0062] S101, acquiring the minimum wavelength data of the spectrum of the two side cores of the multi-core optical fiber air layer, and recording the spot position data formed by the second-order dispersion of the diffraction grating;

[0063] In the above steps, the multi-core optical fiber air layer refers to the air region between the two side cores of the multi-core optical fiber, which is used to isolate the optical signals of the two side cores; the two side core spectra refer to the spectra of the optical signals output by the two cores on both sides of the air layer of the multi-core optical fiber; the minimum wavelength data refers to the wavelength data corresponding to the optical signal with the smallest wavelength value in the two side core spectra; the second-order dispersion of the diffraction grating refers to the dispersion phenomenon formed after the diffraction grating performs second-order dispersion on the optical signal; and the spot position data refers to the position coordinate data of the spot formed after the second-order dispersion.

[0064] In the embodiments of the present application, first, the minimum wavelength data is extracted from the spectrum data of the two side cores of the multi-core optical fiber air layer. For example, in the high-temperature and high-pressure pipeline monitoring scene, the multi-core optical fiber is attached to the surface of the pipeline, and the two side cores output optical signals containing different wavelengths. The spectrum detection device receives these optical signals and forms a spectrum curve, which presents multiple fluctuating peaks and troughs. The wavelength corresponding to the trough is the minimum wavelength in the spectrum. By identifying the trough position of the spectrum curve at each moment, the wavelength value corresponding to the position is recorded to obtain the minimum wavelength data of each of the two side cores. Secondly, the spot position data formed by the second-order dispersion of the diffraction grating is recorded. For example, in the above-mentioned scene, the optical signals output by the multi-core optical fiber first enter the diffraction grating for first-order dispersion, separating the optical signals of different wavelengths. These optical signals are subjected to second-order dispersion, i.e., second-order dispersion, by the diffraction grating again, and the formed spot is projected on the sensing surface of the preset position detection device. The device determines the X-axis and Y-axis coordinates of the spot center on the sensing surface by sensing the light area of the spot, and records the coordinate information every fixed time interval to form continuous spot position data.

[0065] In practical applications, a high-temperature and high-pressure pipeline A of a certain chemical enterprise needs to be monitored for a long time. A multi-core optical fiber B is fixed and attached to the outer surface of the key monitoring area of the pipeline A. A spectrum detector C is connected to the output end of the multi-core optical fiber B through a fiber connector to collect spectrum data in real time. A diffraction grating D and a photoelectric array E are installed in sequence on the light signal propagation path, and the photoelectric array E is connected to a data recording device F. The spectrum detector C continuously receives the spectrum signals transmitted by the two fiber cores. Every 0.5 seconds, a spectrum curve is generated, and the lowest wavelength corresponding to the wave trough is extracted. The lowest wavelength data of the two fiber cores are stored in the device F in real time. At the same time, the light spot after two-stage dispersion by the diffraction grating D is projected on the photoelectric array E. The photoelectric array E detects the light spot center coordinates every 0.5 seconds, and the X and Y coordinate data are synchronously transmitted to the device F, forming a synchronous lowest wavelength data sequence and a light spot position data sequence.

[0066] In the overall scheme of the above step S101, the lowest wavelength data and the light spot position data of the two fiber cores are synchronously acquired, providing initial data sources for subsequent analysis of strain and temperature changes. The synchronous recording of the two kinds of data ensures the time correlation of the strain and temperature related information in subsequent processing, laying a reliable data foundation for the decoupling analysis of the two.

[0067] S102, using a diffraction grating to perform two-stage light splitting on the composite light output by the multi-core optical fiber, projecting the spectrum of the two fiber cores into non-overlapping areas of a photoelectric array to generate independent spectrum data, and blocking the coupling of the two fiber light paths based on the independent spectrum data to enhance the strain sensitive characteristics;

[0068] Optionally, step S102 can specifically include the following steps:

[0069] S1021, inputting the composite light output by the multi-core optical fiber into a diffraction grating, performing first-stage light splitting on the composite light by the diffraction grating to obtain preliminary separated signals of different wavelengths, and performing second-stage light splitting on the preliminary separated signals by the diffraction grating to obtain light signals of different wavelengths with an expanded separation degree;

[0070] S1022, arranging a photoelectric array at the light signal exit of the diffraction grating, dividing the photoelectric array into two independent areas that do not overlap, and projecting the light signals after the two-stage light splitting into the two independent areas respectively;

[0071] S1023, forming respective spectrum images according to the projection of the light signals in the respective corresponding photoelectric array areas, converting the spectrum images into electrical signals by the photoelectric array, generating independent spectrum data of the two fiber cores respectively, and reflecting the changes of the light signals of the two fiber cores affected by the strain through the independent spectrum data;

[0072] S1024, an air layer is arranged between the two sides of the fiber core of the multicore optical fiber, and the air layer is used to prevent the optical signals between the two sides of the fiber core from being coupled with each other, so as to enhance the strain-sensitive characteristic.

[0073] In the above steps, the composite light refers to the mixed light signal output by the multicore optical fiber and containing the optical signals of the two sides of the fiber core; the secondary light splitting refers to the process of performing twice light splitting on the optical signal by using the diffraction grating; the preliminary separated signal refers to the optical signal in which the different wavelength optical signals are separated after the first light splitting; the light signal with an expanded separation degree refers to the optical signal in which the separation distance between the different wavelength optical signals is larger after the second light splitting; the photoelectric array refers to a device for receiving the optical signal and composed of a plurality of photoelectric sensing units; the independent area refers to two areas that are not overlapped with each other and are divided on the photoelectric array and are respectively used for receiving the optical signals of the two sides of the fiber core; the spectrum image refers to the image of the wavelength distribution formed by the optical signal in the area of the photoelectric array; the independent spectrum data refers to the spectrum data formed by converting the optical signals of the two sides of the fiber core; the air layer refers to the air area between the two sides of the fiber core of the multicore optical fiber; the optical path coupling refers to the phenomenon that the optical signals between the two sides of the fiber core are transmitted to each other; and the strain-sensitive characteristic refers to the response capability of the fiber core optical signal to the change of the pipeline strain.

[0074] In the embodiment of the application, first, the composite light output by the multicore optical fiber is input into the diffraction grating through step S1021, the preliminary separated signal of different wavelengths is obtained after the first light splitting of the diffraction grating, and the light signal with an expanded separation degree of different wavelengths is obtained after the second light splitting of the diffraction grating. For example, in the high-temperature and high-pressure pipeline monitoring scene, after the composite light output by the multicore optical fiber enters the diffraction grating, the first light splitting causes the different wavelength components in the optical signal to be refracted at different angles to form optical signal beams with a small interval. These preliminary separated optical signal beams pass through the diffraction grating again, the wavelength interval is further expanded after the second light splitting, the distance between the different wavelength optical signal beams is increased, and the optical signal beams that are more easily distinguished are formed.

[0075] Secondly, the photoelectric array is arranged at the light signal exit of the diffraction grating through step S1022, the photoelectric array is divided into two independent areas that are not overlapped with each other, and the optical signal after the secondary light splitting is projected into the two independent areas. For example, in the above scene, the photoelectric array is fixedly installed on one side of the diffraction grating outputting the optical signal, the array is divided into two independent areas of the left side and the right side along the horizontal axis through the preset area division parameters, each area corresponds to the optical signal of one fiber core, after the secondary light splitting, the optical signal beam of the left side fiber core is accurately projected into the left side area, the optical signal beam of the right side fiber core is projected into the right side area, and there is no overlapping part between the edges of the two areas.

[0076] Then, by step S1023, according to the projection of the optical signal in the respective corresponding photoelectric array area, the respective spectral image is formed, the spectral image is converted into an electrical signal by the photoelectric array, the independent spectral data of the two side cores is generated, and the change of the optical signal of the two side cores affected by the strain is reflected by the independent spectral data. For example, in the above scenario, the optical signal of the left side core forms a spectral image composed of different brightness points in the left area of the photoelectric array, and different brightness points correspond to the intensity of the optical signal of different wavelengths. The optical signal of the right side core forms a similar spectral image in the right area. Each sensing unit of the photoelectric array converts the received optical signal intensity into a corresponding electrical signal value, and after integration, the independent spectral data of the left side core and the right side core is formed. When the pipe strain changes, the wavelength distribution characteristics of these data will change accordingly.

[0077] Finally, by step S1024, an air layer is arranged between the two side cores of the multi-core optical fiber, and the air layer prevents the optical signals between the two side cores from being coupled with each other, so as to enhance the strain sensitivity. For example, in the above scenario, a specific thickness of air layer is reserved between the two side cores during the production of the multi-core optical fiber. The air layer has a large difference in optical characteristics with the cores, which blocks the transmission path of the optical signal between the two side cores, so that the optical signal of the left side core only propagates in its own path, and the optical signal of the right side core also propagates independently, avoiding mutual interference, so that the optical signal is more susceptible to strain and produces identifiable changes.

[0078] In actual application, when a chemical enterprise monitors the strain of the key weld area of a high-temperature and high-pressure pipeline A, a multi-core optical fiber B is fixed near the weld along the axial direction of the pipeline. The composite light output by the multi-core optical fiber B is introduced into a diffraction grating C through an optical lens. After the first light splitting, the wavelength components of 500-800 nm in the optical signal are preliminarily separated to form optical signal beams with an interval of about 1 mm. These optical signal beams are subjected to the second light splitting by the diffraction grating C again, and the separation interval is expanded to 5 mm. A photoelectric array D is installed at a distance of 10 cm from the light signal exit of the diffraction grating C, and is divided into left and right independent areas with a size of 10x10 mm. The optical signal of the left side core is projected to the left area after the second light splitting, and the optical signal of the right side core is projected to the right area. The sensing units of the photoelectric array D convert the spectral images of the left and right areas into electrical signals, and after being processed by a data collector, the independent spectral data of the left and right side cores is generated and stored. At the same time, the 0.5 mm thick air layer between the two side cores of the multi-core optical fiber B effectively prevents the coupling of the optical signals. When the pipeline A produces a slight strain due to internal pressure fluctuation, the wavelength peak position of the independent spectral data appears a significant shift, which accurately reflects the strain change.

[0079] In the overall scheme of step S102, the separation effect of optical signals of different wavelengths is significantly improved through secondary light splitting, and the optical signals of the two side cores are more easily distinguished; the division of independent regions avoids mutual interference of optical signals during reception, ensuring the independence of the signals; the generation of independent spectral data converts the characteristics of optical signals into processable electrical signal data, providing a clear input for subsequent analysis; the setting of the air layer cuts off the optical path coupling path of the two side cores, reduces irrelevant signal interference, and makes the response of optical signals to the pipe strain more direct and sensitive, thereby improving the recognizability and reliability of the strain signal as a whole, and providing a high-quality signal basis for subsequent strain and temperature decoupling analysis.

[0080] The specific implementation schematic diagram of the grating demodulation multi-core optical fiber strain and temperature decoupling method provided by the embodiment of the application is shown in Figure 2 as follows, which includes the following contents:

[0081] S103, a double-task analysis network of a parallel structure is constructed, continuous waveform comparison is performed through a strain analysis branch of the double-task analysis network based on the lowest wavelength data, a strain wavelength offset is obtained, dynamic trajectory tracking is performed through a temperature compensation branch of the double-task analysis network based on the spot position data, and a temperature wavelength correction is obtained.

[0082] Optionally, step S103 can specifically include the following steps:

[0083] S1031, a double-task analysis network with a parallel processing path is built, the network includes two parallel processing branches, i.e., a strain analysis branch and a temperature compensation branch, and the two branches share part of initial processing units;

[0084] S1032, through the strain analysis branch, the waveform features corresponding to the lowest wavelength data are extracted, the waveform features at the current moment are continuously compared with the waveform features at the previous moment, the difference between the two waveforms is recorded, and a strain wavelength offset is obtained.

[0085] The step S1032 can specifically include the following processes: dividing the minimum wavelength data into data segments according to a preset time interval, each data segment corresponding to minimum wavelength data of a time point, and inputting the minimum wavelength data of each time point into the strain analysis branch in sequence; based on the input minimum wavelength data, identifying, by the strain analysis branch, a vertex position, an inflection point position and a fluctuation interval range in a waveform corresponding to each time point data as a waveform feature of each time point; calculating a difference value of the vertex position and a difference value of the inflection point position according to the waveform feature of the current time point and the waveform feature of the previous time point, and determining a change amount of a fluctuation interval boundary by overlapping and comparing the fluctuation interval ranges of the current time point and the previous time point; and comprehensively calculating the difference value of the vertex position, the difference value of the inflection point position and the change amount of the fluctuation interval boundary, recording the difference between two waveforms, and obtaining a strain wavelength offset.

[0086] S1033, tracking, by the temperature compensation branch, a position change trajectory of the light spot at different time points, continuously recording position points on the position change trajectory, analyzing a moving amplitude and a moving direction of the position points, and obtaining a temperature wavelength correction amount.

[0087] The step S1033 can specifically include the following processes: collecting light spot position data at different time points according to a preset time interval, and inputting the light spot position data into the temperature compensation branch in sequence; identifying, by the temperature compensation branch, a spatial position of the light spot at each time point as a position point, and connecting the position points at different time points in time sequence to form a position change trajectory of the light spot; selecting position points at adjacent time points in the position change trajectory, calculating a straight line distance between the position points at the adjacent time points as a moving amplitude, and determining a spatial offset direction of a position point at a later time point relative to a position point at a previous time point as a moving direction; recording the moving amplitude and the moving direction in a plurality of continuous time periods, and associating and calculating the moving amplitude and an offset amount corresponding to the moving direction to obtain a temperature wavelength correction amount.

[0088] In the above steps, the double-task analysis network of the parallel structure refers to an analysis system with two paths processing different tasks at the same time, for processing strain and temperature related data respectively; the strain analysis branch refers to the path in the double-task analysis network that is specially used for processing strain related data; the temperature compensation branch refers to the path in the double-task analysis network that is specially used for processing temperature related data; the shared initial processing unit refers to an early data processing component used by the strain analysis branch and the temperature compensation branch; the waveform feature refers to a representative feature in a waveform formed by the lowest wavelength data, including a vertex position, an inflection point position and a fluctuation interval range; the vertex position refers to a position corresponding to a wave peak or a wave trough in the waveform; the inflection point position refers to a position where a change trend changes in the waveform; the fluctuation interval range refers to a fluctuation interval of the waveform in a certain wavelength range; the strain wavelength offset refers to a wavelength position change amount caused by strain; the position change trajectory refers to a path formed by connecting positions of a light spot at different times in time sequence; the moving amplitude refers to a distance between positions of the light spot at adjacent times; the moving direction refers to a spatial offset direction of the light spot at a later time relative to the light spot at an earlier time; and the temperature wavelength correction amount refers to an amount of correction needed for the wavelength due to temperature change.

[0089] In the embodiments of the present application, first, a double-task analysis network with parallel processing paths is built through step S1031, which contains two parallel processing branches, a strain analysis branch and a temperature compensation branch, and the two branches share part of the initial processing unit. For example, in the high temperature and high pressure pipeline monitoring scene, the built double-task analysis network contains two parallel processing paths, one of which is the strain analysis branch, which is specially used for processing the lowest wavelength data, and the other is the temperature compensation branch, which is specially used for processing the light spot position data, and the two branches share data receiving, format conversion and other processing components in the initial stage of data processing to improve the data processing efficiency.

[0090] Secondly, by step S1032, the minimum wavelength data is divided into data segments at preset time intervals, each data segment corresponding to the minimum wavelength data of a time, and the minimum wavelength data of each time is input into the strain analysis branch in turn; based on the input minimum wavelength data, the strain analysis branch identifies the vertex position, inflection point position and fluctuation interval range in the waveform corresponding to each time data as the waveform characteristics of each time; according to the waveform characteristics of the current time and the waveform characteristics of the previous time, the difference values of the corresponding vertex positions and the difference values of the inflection point positions are calculated, the fluctuation interval ranges of the current time and the previous time are compared, and the change amount of the fluctuation interval boundary is determined; the difference between the vertex position difference value, the inflection point position difference value and the fluctuation interval boundary change amount is calculated, and the strain wavelength offset is obtained. For example, in the above scenario, the minimum wavelength data is divided into multiple data segments at a time interval of 0.5 seconds, each data segment corresponding to a waveform of a time, and after these data are input into the strain analysis branch in turn, the branch identifies that the peak vertex of a waveform at a certain time is at a position of 600 nm, the inflection points are at positions of 590 nm and 610 nm, and the fluctuation interval is 580-620 nm, the vertex corresponding to the previous time is at a position of 599 nm, the inflection points are at positions of 589 nm and 609 nm, and the interval is 579-619 nm, the vertex difference value is 1 nm, the inflection point difference value is 1 nm, and the interval boundary change amount is 1 nm, and the strain wavelength offset of the time period is obtained by comprehensively calculating these data.

[0091] Finally, by step S1033, the light spot position data at different times is collected at a preset time interval, and the light spot position data is input into the temperature compensation branch in turn; the temperature compensation branch identifies the spatial position of the light spot at each time, and marks it as a position point; the position points at different times are connected in time sequence to form a position change trajectory of the light spot; the position points at adjacent times in the position change trajectory are selected, the straight line distance between the position points at adjacent times is calculated as the moving amplitude, and the spatial offset direction of the position point at the next time relative to the position point at the previous time is determined as the moving direction; the moving amplitudes and moving directions in continuous multiple time periods are recorded, the moving amplitudes and the offset amounts corresponding to the moving directions are associated and calculated to obtain the temperature wavelength correction amount. For example, in the above scenario, the light spot position data is collected at an interval of 0.5 seconds to obtain the coordinates of the position at t1 (10, 20), the position at t2 (12, 21), the position at t3 (14, 22), etc., which are input into the temperature compensation branch, and the branch marks and connects these position points into a trajectory, calculates the straight line distance from t1 to t2 as , the direction is right up, the distance from t2 to t3 is also about 2.24, the direction is right up, and after recording these amplitudes and directions, the temperature wavelength correction amount is obtained by associated calculation.

[0092] In practical applications, a certain energy enterprise builds a double-task analysis network B for data processing in the long-term operation monitoring of high-temperature and high-pressure pipeline A. The network includes a parallel strain analysis branch C and a temperature compensation branch D, both of which share initial processing units E such as data receiving modules and format conversion modules to reduce repeated operations. During monitoring, the multi-core optical fiber F on the surface of the pipeline A collects the minimum wavelength data of the two sides every 0.5 seconds. These data are divided into t0, t1, t2, …, tn data segments in chronological order and input into the strain analysis branch C in turn. The branch C analyzes the waveform of each data segment, for example, identifies that the vertex of the trough of the waveform at t5 is located at 550 nm, the two inflection points are at 545 nm and 555 nm, and the fluctuation interval is 540-560 nm, while the vertex at t4 is at 548 nm, the inflection points are at 543 nm and 553 nm, and the interval is 538-558 nm. By calculation, the vertex position difference is 2 nm, the inflection point difference is 2 nm, and the interval boundary change is 2 nm. The strain wavelength shift amount of the period from t4 to t5 is obtained by comprehensively considering these differences. At the same time, the second-order dispersed light spot generated by the diffraction grating G is recorded by the photoelectric array H every 0.5 seconds to obtain position points t0: (8, 10), t1: (9, 11), t2: (10, 12), …, t5: (13, 15). After these data are input into the temperature compensation branch D, the branch connects the position points in chronological order to form a continuous track, calculates the straight-line distance from t4 (12, 14) to t5 (13, 15) as , and the moving direction is right up. After recording the amplitudes and directions of multiple periods in succession, the temperature wavelength correction amount of each period is obtained by correlation calculation. The strain wavelength shift amount and the temperature wavelength correction amount are stored in the database I synchronously, providing data support for subsequent decoupling processing.

[0093] In the overall scheme of the above step S103, the double-task analysis network with a parallel structure is built to realize the synchronous and parallel processing of strain and temperature-related data, avoiding the efficiency bottleneck of single-path processing and improving the timeliness of data processing. The strain analysis branch accurately captures the subtle changes in wavelength caused by strain through continuous comparison and difference calculation of waveform features, providing reliable parameters for subsequent strain quantization. The temperature compensation branch effectively extracts the position change characteristics related to temperature through dynamic tracking and amplitude and direction analysis of the light spot track, providing a direct basis for temperature influence correction. The shared initial processing units simplify the data preprocessing process, reduce resource consumption, and overall improve the professionalism, accuracy, and efficiency of data processing, laying a key parameter foundation for accurate decoupling of strain and temperature.

[0094] S104, based on the independent spectral data, combining the time series data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, dynamically adjusting the shared layer weight of the dual-task analysis network, and generating a strain demodulation value decoupled from temperature;

[0095] Optionally, step S104 can specifically include the following steps:

[0096] S1041, obtaining the generated independent spectral data, collecting the time series data formed by the change of the strain wavelength offset over time, and the amplitude fluctuation data of the temperature wavelength correction;

[0097] S1042, inputting the independent spectral data, time series data and amplitude fluctuation data into the shared layer of the dual-task analysis network at the same time, and analyzing the optical signal characteristics of the two side cores in the independent spectral data through the shared layer;

[0098] S1043, based on the optical signal characteristics, combining the change trend of the strain wavelength offset in the time series data and the fluctuation range of the temperature wavelength correction in the amplitude fluctuation data, dynamically adjusting the action strength of each processing unit in the shared layer;

[0099] S1044, by enhancing the shared layer weight of the strain-related signal characteristics in the optical signal characteristics, and weakening the shared layer weight of the temperature-related signal characteristics, an adjusted dual-task analysis network is obtained;

[0100] S1045, processing the input data through the adjusted dual-task analysis network to generate a strain demodulation value eliminating the influence of temperature, i.e., a strain demodulation value decoupled from temperature.

[0101] In the above steps, the independent spectral data refers to the spectral data formed after the optical signals of the two side cores of the multicore optical fiber are converted, which is used to reflect the changes of the optical signals of the two side cores affected by the outside world; the time series data of the strain wavelength offset refers to the data sequence formed by the strain wavelength offset arranged in time sequence, which is used to reflect the time trend of the strain change; the amplitude fluctuation data of the temperature wavelength correction refers to the fluctuation data of the numerical value of the temperature wavelength correction changing over time; the shared layer of the dual-task analysis network refers to the intermediate data processing level commonly used by the strain analysis branch and the temperature compensation branch, which is used for unified preprocessing and feature extraction of input data; the shared layer weight refers to the action strength parameter of each processing unit in the shared layer to different signal characteristics, the greater the weight, the more significant the influence on the corresponding signal characteristics; the optical signal characteristics refer to the optical signal properties contained in the independent spectral data that can reflect the influence of strain or temperature; the action strength of the processing unit refers to the processing intensity of each processing component in the shared layer; the strain demodulation value decoupled from temperature refers to the demodulation result value reflecting only the strain change after eliminating the influence of temperature.

[0102] In the embodiment of the present application, first, through step S1041, the generated independent spectrum data is obtained, the time series data formed by the strain wavelength shift amount changing with time is collected, and the amplitude fluctuation data of the temperature wavelength correction amount is collected. For example, in the high temperature and high pressure pipeline monitoring scene, the independent spectrum data of the two side cores is called from the data storage unit, the strain wavelength shift amount recorded every 0.5 seconds in the past 10 minutes, such as 0.2 nm, 0.3 nm, 0.25 nm, is collected to form a time series, and the amplitude fluctuation of the temperature wavelength correction amount at the same period, such as 0.1 nm~0.15 nm, 0.12 nm~0.18 nm, is collected.

[0103] Secondly, through step S1042, the independent spectrum data, the time series data and the amplitude fluctuation data are simultaneously input into the shared layer of the dual-task analysis network, and the light signal characteristics of the two side cores in the independent spectrum data are analyzed through the shared layer. For example, in the above-mentioned scene, after the three types of data are synchronously input into the shared layer, the shared layer analyzes the independent spectrum data, and identifies the wavelength drift characteristics related to the strain of the pipeline, such as the linear shift of the wavelength with the change of the pressure, and the wavelength fluctuation characteristics related to the temperature, such as the overall shift of the wavelength with the increase of the temperature.

[0104] Then, through step S1043, based on the light signal characteristics, the change trend of the strain wavelength shift amount in the time series data and the fluctuation range of the temperature wavelength correction amount in the amplitude fluctuation data, the action strength of each processing unit in the shared layer is dynamically adjusted. For example, in the above-mentioned scene, according to the identified light signal characteristics, it is found that the strain wavelength shift amount in the time series presents a periodic increasing trend, such as increasing with the periodic fluctuation of the pipeline pressure, and the fluctuation range of the temperature wavelength correction amount is stable at 0.1~0.2 nm, and accordingly the shared layer enhances the action strength of the processing unit sensitive to the strain-related characteristics and weakens the action strength of the processing unit sensitive to the temperature-related characteristics.

[0105] Then, through step S1044, by enhancing the shared layer weight of the strain-related signal characteristics in the light signal characteristics and weakening the shared layer weight of the temperature-related signal characteristics, an adjusted dual-task analysis network is obtained. For example, in the above-mentioned scene, the weight of the processing unit in the shared layer sensitive to the time series change of the strain wavelength shift amount is adjusted from 0.3 to 0.6, and the weight of the processing unit sensitive to the amplitude fluctuation of the temperature wavelength correction amount is reduced from 0.4 to 0.1, so that the network focuses more on capturing the strain-related signals.

[0106] Finally, by step S1045, the input data is processed by the adjusted dual-task analysis network to generate strain demodulation values that eliminate the temperature influence, i.e., temperature-decoupled strain demodulation values. For example, in the above scenario, the adjusted network processes the newly input independent spectral data, the latest time series data, and the amplitude fluctuation data, filters out the wavelength change components caused by the temperature factor, and outputs demodulation values that only reflect the strain of the pipeline.

[0107] In actual application, in the monitoring system of a high-temperature and high-pressure pipeline A of a certain chemical enterprise, the data processing module B acquires the independent spectral data generated by the multi-core optical fiber C at an interval of 0.5 seconds, the spectral range of the left core is 500-600 nm, and the spectral range of the right core is 550-650 nm, and the strain wavelength offset time series data in the past 30 minutes such as t1: 0.2 nm, t2: 0.22 nm, …, t360: 0.5 nm and the amplitude fluctuation data of the temperature wavelength correction amount such as a fluctuation range of 0.1-0.18 nm are collected at the same time. These data are synchronously input into the shared layer E of the dual-task analysis network D, and the shared layer E analyzes and finds that the left core in the independent spectral data has a stable offset characteristic that changes with the pipeline pressure at 550 nm, and the right core has a fluctuation characteristic that changes with the ambient temperature at 600 nm. Combined with the increasing trend of the strain offset in the time series, which increases by about 0.05 nm every 5 minutes, and the stable fluctuation range of the temperature correction amount, the shared layer E adjusts the weight of the processing unit F sensitive to the strain characteristic from 0.25 to 0.7 and adjusts the weight of the processing unit G sensitive to the temperature characteristic from 0.3 to 0.08. After the adjusted network processes the newly input t361 time data, the temperature-decoupled strain demodulation value generated is 132 με, which has eliminated the temperature interference and only reflects the actual strain state of the pipeline.

[0108] In the overall scheme of the above step S104, the independent spectral data, the strain time series, and the temperature fluctuation data are integrated to provide a multi-dimensional basis for network weight adjustment; the dynamic adjustment of the shared layer weight realizes the enhancement of the strain-related signals and the suppression of the temperature-related signals, so that the network focuses more accurately on the strain characteristic; and the finally generated temperature-decoupled strain demodulation value effectively eliminates the interference of the temperature factor, improves the purity and accuracy of the strain measurement, provides reliable core data for subsequent strain monitoring and analysis, and further perfects the decoupling mechanism of strain and temperature.

[0109] S105, based on the temperature-decoupled strain demodulation value, generating a standardized strain characteristic signal through photoelectric signal conversion, transmitting the characteristic signal to a monitoring system, reconstructing an axial strain dynamic distribution map of the multi-core optical fiber, and synchronously displaying a temperature compensation state curve.

[0110] Optionally, step S105 can specifically include the following steps:

[0111] S1051, input the temperature-decoupled strain demodulation value to an optoelectronic conversion device, and convert the optical signal corresponding to the strain demodulation value into an electrical signal through the optoelectronic conversion device;

[0112] S1052, perform standardization processing on the converted electrical signal, so that the amplitude and range of the signal are within a preset standard interval, and generate a standardized strain characteristic signal;

[0113] S1053, send the strain characteristic signal to a monitoring system through a data transmission line, and after the monitoring system receives the signal, arrange the strain characteristic signals corresponding to different positions in the axial direction according to the axial position information of the multi-core optical fiber, and form a dynamic distribution diagram of the axial strain of the multi-core optical fiber;

[0114] S1054, extract temperature wavelength correction data through the monitoring system, present the change of the temperature wavelength correction data over time in a curve form, and display the dynamic distribution diagram and the temperature wavelength correction data synchronously on the monitoring interface.

[0115] In the above steps, the temperature-decoupled strain demodulation value refers to a demodulation result value reflecting only the strain change after eliminating the temperature influence; the optoelectronic conversion device refers to a device for converting an optical signal into an electrical signal, used to realize the conversion of the optical signal into the electrical signal; the standardization processing refers to a processing process of adjusting the amplitude and range of the electrical signal to make it meet the preset standard interval; the standardized strain characteristic signal refers to a strain-related electrical signal whose amplitude and range are within the standard interval after standardization processing; the data transmission line refers to a physical or wireless transmission channel for transmitting signals; the monitoring system refers to a system for receiving and processing signals and displaying monitoring results; the axial position information of the multi-core optical fiber refers to the coordinate information of different positions of the multi-core optical fiber along the axial direction of the pipeline; the axial strain dynamic distribution diagram refers to a strain distribution image arranged according to the axial position of the multi-core optical fiber, which can dynamically reflect the strain state of different positions; the temperature wavelength correction data refers to wavelength-related data for correcting the temperature influence; and the temperature compensation state curve refers to a curve reflecting the change of the temperature wavelength correction data over time.

[0116] In the embodiment of the application, first, the temperature-decoupled strain demodulation value is input to the optoelectronic conversion device through step S1051, and the optical signal corresponding to the strain demodulation value is converted into an electrical signal through the optoelectronic conversion device. For example, in the high-temperature and high-pressure pipeline monitoring scene, the temperature-decoupled strain demodulation value is transmitted to the optoelectronic conversion device in the form of an optical signal, and the photoelectric sensing element inside the device converts the strength of the optical signal into a corresponding voltage signal, such as the stronger the light intensity, the higher the voltage, to realize the conversion of the optical signal into the electrical signal.

[0117] Secondly, by step S1052, the converted electrical signal is standardized to make the amplitude and range of the signal within the preset standard interval, and a standardized strain characteristic signal is generated. For example, in the above scenario, the converted electrical signal voltage range is between 0.5-3V, which is adjusted to the preset 1-5V standard interval through standardization, so that the signals at different times and different positions have a unified amplitude reference, and a standardized strain characteristic signal is generated.

[0118] Then, by step S1053, the strain characteristic signal is sent to the monitoring system through the data transmission line. After receiving the signal, the monitoring system arranges the strain characteristic signals corresponding to different positions in the axial direction according to the axial position information of the multi-core optical fiber, and forms a dynamic distribution diagram of the axial strain of the multi-core optical fiber. For example, in the above scenario, the standardized strain characteristic signal is sent to the monitoring system through the wired transmission line. The system has the position coordinates of the multi-core optical fiber along the axial direction of the pipeline, such as 0m, 0.5m, 1m, …, 5m. The strain signal values corresponding to each position are mapped to the image in the order of the coordinates, forming a dynamic distribution diagram that updates with time, and intuitively displaying the strain size at different positions.

[0119] Finally, by step S1054, the temperature wavelength correction data is extracted by the monitoring system, and the change of the temperature wavelength correction data with time is presented in the form of a curve and displayed on the monitoring interface synchronously with the dynamic distribution diagram. For example, in the above scenario, the monitoring system extracts the temperature wavelength correction data of the same period from the database, draws a curve with time as the horizontal axis and the correction amount as the vertical axis, and displays the curve and the axial strain dynamic distribution diagram in the same interface in different regions. The operator can observe the strain distribution and the temperature compensation effect at the same time.

[0120] In practical application, in the monitoring of a high-temperature and high-pressure pipeline A of an energy enterprise, the strain demodulation values decoupled by temperature are, for example, 120με, 125με, etc. The photoelectric conversion device B converts the corresponding optical signals into electrical signals with a voltage range of 0.8-2.5V. The signal processing module C standardizes the electrical signals and adjusts them to a standard interval of 1-5V, generating a standardized strain characteristic signal. These signals are sent to the monitoring system E through the optical fiber transmission line D. The system E arranges the strain signals at different points according to the position information of the multi-core optical fiber F along the axial direction of the pipeline, i.e., 0m to 10m, with a monitoring point every 0.5m. The axial strain dynamic distribution diagram is generated on the left side of the interface and updates in real time. The red area represents the high strain area. At the same time, the system E extracts temperature wavelength correction data such as 0.12nm, 0.15nm, etc., and draws a temperature compensation state curve on the right side of the interface. The horizontal axis represents the monitoring time 0-60 minutes, and the vertical axis represents the correction amount. The dynamic distribution diagram and the temperature compensation state curve are refreshed synchronously, which is convenient for the operator to comprehensively judge the pipeline state.

[0121] In the overall scheme of step S105 above, the form conversion of strain signal is realized through photoelectric conversion, providing an adapted signal type for subsequent transmission and processing; standardized processing unifies the signal format, ensuring the comparability of different data and system compatibility; the dynamic distribution map intuitively presents the strain distribution state of the multi-core optical fiber axis, which is convenient for quickly identifying high strain areas; the synchronous display of the temperature compensation state curve provides a reference for the reliability of strain data, and the overall intuitiveness, readability and practicality of the monitoring results are improved, providing clear visualization support for the safety monitoring of high temperature and high pressure pipelines.

[0122] The following is a complete embodiment for steps S101 to S105:

[0123] like Figure 3 As shown, in the long-term operation monitoring of a high-temperature and high-pressure pipeline A in a chemical enterprise, the method described in this application is used to achieve safety monitoring. A multi-core optical fiber B is attached to the critical area along the pipeline axis, with an internal air layer isolating the two fiber cores. A diffraction grating C, a photoelectric array D, and a data processing unit E are sequentially installed at the output end. The monitoring system F is connected to the processing unit via a line. During data acquisition, a spectrometer obtains the lowest wavelength data of the spectra of the two fiber cores, approximately 550 nm on the left and approximately 600 nm on the right. The photoelectric array... Record the initial positions of the second-order dispersion spot of the diffraction grating at 10 and 15. During the signal separation stage, the diffraction grating performs a second spectral split on the composite light. After the first split, a second spectral split widens the interval, and the left-side spectrum is projected onto the left-side region of the photoelectric array. Each row of sensing units (rows 6-10) generates independent spectral data, with an air layer blocking optical path coupling to ensure signal independence. A dual-task analysis network is built during the data processing stage. The strain analysis branch divides the data into 0.5-second intervals to identify waveform peaks such as the 550nm trough, inflection points at 545nm and 555nm, and intervals. The difference between the wavelength and the previous time step is calculated to obtain the strain wavelength shift; the temperature compensation branch tracks the change in the spot position at time t1. time Connect the points to form a trajectory, and calculate the movement range of adjacent points, such as... The temperature wavelength correction is obtained from the direction. During dynamic adjustment, the network sharing layer receives data, analyzes the characteristics, adjusts the weight of the strain-sensitive unit from 0.3 to 0.6, and decreases the weight of the temperature-sensitive unit from 0.4 to 0.1, generating temperature-decoupled strain demodulation values ​​as follows: During the results demonstration phase, the photoelectric conversion device converts the demodulated values ​​into... Electrical signals, standardized as The characteristic signal is transmitted to the monitoring system F, and the system is positioned according to the fiber optic axis. Draw dynamic distribution map and mark high strain area with red every 0.5m, and extract temperature correction data to draw time-correction curve with horizontal axis 0-60 minutes and vertical axis , to realize real-time monitoring.

[0124] The grating demodulation multi-core optical fiber strain and temperature decoupling method provided in the application provides double-dimensional basic data support for strain and temperature decoupling by synchronously collecting the lowest wavelength data and spot position data of the cores on both sides of the multi-core optical fiber. The secondary light splitting and independent area projection design, combined with the air layer blocking light path coupling, effectively reduces signal interference and significantly enhances the independence and sensitivity of the strain signal. The parallel double-task analysis network realizes the synchronous extraction of strain and temperature related parameters, the continuous waveform comparison accurately captures the strain wavelength shift characteristics, and the dynamic trajectory tracking effectively identifies the temperature wavelength correction rule. By dynamically adjusting the shared layer weight, the strain signal characteristics are strengthened and the temperature interference is weakened, successfully generating strain demodulation values decoupled from temperature, eliminating the cross influence of temperature on the measurement results. Finally, through standardized signal conversion and visual display, the axial strain dynamic distribution and temperature compensation state are intuitively presented, which overall improves the accuracy, stability and intuitiveness of strain measurement, and provides reliable technical support for structure strain monitoring in complex environments such as high temperature and high pressure.

[0125] Figure 4 A specific implementation structure diagram of a grating demodulation multi-core optical fiber strain and temperature decoupling system provided for an embodiment of the application, with reference to Figure 4 The system can include:

[0126] The acquisition module 41 is configured to acquire the lowest wavelength data of the core spectra on both sides of the air layer of the multi-core optical fiber, and record the spot position data formed by the second-order dispersion of the diffraction grating;

[0127] The blocking module 42 is configured to use the diffraction grating to perform secondary light splitting on the composite light output by the multi-core optical fiber, project the core spectra on both sides into non-overlapping areas in the photoelectric array respectively, generate independent spectrum data, and block the coupling of the two core light paths based on the independent spectrum data to enhance the strain sensitive characteristics;

[0128] The construction module 43 is configured to construct a double-task analysis network of a parallel structure, perform continuous waveform comparison through a strain analysis branch of the double-task analysis network based on the lowest wavelength data to obtain a strain wavelength shift amount, and perform dynamic trajectory tracking through a temperature compensation branch of the double-task analysis network based on the spot position data to obtain a temperature wavelength correction amount;

[0129] The adjusting module 44 is configured to dynamically adjust the shared layer weight of the dual-task analysis network based on the independent spectrum data, the time sequence data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, and generate a temperature-decoupled strain demodulation value.

[0130] The reconstructing module 45 is configured to generate a normalized strain characteristic signal by photoelectric signal conversion based on the temperature-decoupled strain demodulation value, transmit the characteristic signal to a monitoring system, reconstruct an axial strain dynamic distribution map of the multicore optical fiber, and synchronously display a temperature compensation state curve.

[0131] The grating demodulation multicore optical fiber strain and temperature decoupling system according to the embodiments of the present application is used to implement the grating demodulation multicore optical fiber strain and temperature decoupling method described above, and the specific embodiments of the grating demodulation multicore optical fiber strain and temperature decoupling system can be found in the embodiment part of the grating demodulation multicore optical fiber strain and temperature decoupling method described above, and the specific embodiments can be referred to the description of the corresponding embodiment part, which will not be repeated here.

[0132] The present application further provides an electronic device, comprising a memory for storing a computer program, and a processor for executing the computer program to implement the steps of the grating demodulation multicore optical fiber strain and temperature decoupling method described above.

[0133] The present application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the steps of the grating demodulation multicore optical fiber strain and temperature decoupling method described above.

[0134] In an exemplary embodiment, the computer readable storage medium described above can include but is not limited to a U disk, a read-only memory, a random access memory, a mobile hard disk, a magnetic disk or an optical disk, and various media that can store computer programs.

[0135] The embodiments of the present application further provide a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the steps of the grating demodulation multicore optical fiber strain and temperature decoupling method described above.

[0136] Those skilled in the art will further realize that the mere concepts, teachings, and embodiments described herein are merely meant to provide an enabling description of the claimed application. Accordingly, modifications and / or additions, other than those explicitly described herein, can be obvious to those skilled in the art in the light of this disclosure. The claimed application is intended to embrace all such modifications and / or additions.

[0137] The optical grating demodulation multi-core optical fiber strain and temperature decoupling method, system, electronic device and storage medium provided by the application are described in detail above. The principles and implementation modes of the application are described in this paper by applying specific examples. The above description of the embodiments is only used to help understand the method of the application and its core idea. It should be pointed out that for those skilled in the art, without departing from the principles of the application, some improvements and modifications can be made to the application, and these improvements and modifications also fall within the protection scope of the application.

Claims

1. A method of strain and temperature decoupling of a multicore fiber with grating demodulation, characterized in that, The method comprises the following steps: Obtain the minimum wavelength data of the two-side fiber core spectrum of the multi-core optical fiber air layer, and record the spot position data formed by the second-order dispersion of the diffraction grating; Use the diffraction grating to perform secondary light splitting on the composite light output by the multi-core optical fiber, project the two-side fiber core spectrum into non-overlapping areas of the photoelectric array respectively, generate independent spectrum data, and enhance the strain sensitive characteristics by blocking the two-core light path coupling based on the independent spectrum data; Construct a double-task analysis network with a parallel structure, perform continuous waveform comparison through the strain analysis branch of the double-task analysis network based on the minimum wavelength data, obtain the strain wavelength shift, perform dynamic trajectory tracking through the temperature compensation branch of the double-task analysis network according to the spot position data, and obtain the temperature wavelength correction value; Based on the independent spectrum data, combine the time series data of the strain wavelength shift and the amplitude fluctuation of the temperature wavelength correction value, dynamically adjust the shared layer weight of the double-task analysis network, and generate the strain demodulation value decoupled from temperature; Based on the strain demodulation value decoupled from temperature, generate a standardized strain characteristic signal through photoelectric signal conversion, transmit the characteristic signal to a monitoring system, reconstruct an axial strain dynamic distribution map of the multi-core optical fiber, and synchronously display a temperature compensation state curve. Based on the independent spectrum data, combine the time series data of the strain wavelength shift and the amplitude fluctuation of the temperature wavelength correction value, dynamically adjust the shared layer weight of the double-task analysis network, and generate the strain demodulation value decoupled from temperature, which comprises: Obtain the generated independent spectrum data, collect the time series data formed by the change of the strain wavelength shift with time and the amplitude fluctuation data of the temperature wavelength correction value; input the independent spectrum data, time series data and amplitude fluctuation data into the shared layer of the double-task analysis network at the same time, analyze the optical signal characteristics of the two-side fiber cores in the independent spectrum data through the shared layer; based on the optical signal characteristics, combine the change trend of the strain wavelength shift in the time series data and the fluctuation range of the temperature wavelength correction value in the amplitude fluctuation data, dynamically adjust the action strength of each processing unit in the shared layer; by enhancing the shared layer weight of the strain-related signal characteristics in the optical signal characteristics and weakening the shared layer weight of the temperature-related signal characteristics, the adjusted double-task analysis network is obtained; the input data is processed through the adjusted double-task analysis network to generate the strain demodulation value eliminating the influence of temperature, i.e. the strain demodulation value decoupled from temperature.

2. The method of claim 1, wherein, Construct a double-task analysis network with a parallel structure, perform continuous waveform comparison through the strain analysis branch of the double-task analysis network based on the minimum wavelength data, obtain the strain wavelength shift, perform dynamic trajectory tracking through the temperature compensation branch of the double-task analysis network according to the spot position data, and obtain the temperature wavelength correction value, which comprises: Build a double-task analysis network with parallel processing paths, the network comprising two parallel processing branches, i.e. a strain analysis branch and a temperature compensation branch, and the two branches share some initial processing units; The strain analysis branch extracts the waveform features corresponding to the lowest wavelength data, continuously compares the waveform features at the current time with the waveform features at the previous time, records the difference between the two waveforms, and obtains the strain wavelength offset; Through the temperature compensation branch, the position change trajectory of the light spot at different times is tracked, the position points on the position change trajectory are continuously recorded, the moving amplitude and direction of the position points are analyzed, and the temperature wavelength correction amount is obtained.

3. The method of claim 2, wherein, Through the strain analysis branch, the waveform features corresponding to the lowest wavelength data are extracted, the waveform features at the current time are continuously compared with the waveform features at the previous time, the difference between the two waveforms is recorded, and the strain wavelength offset is obtained, including: Divide the lowest wavelength data into data segments according to a preset time interval, each data segment corresponds to the lowest wavelength data at a time, and the lowest wavelength data at each time is input into the strain analysis branch in sequence; Based on the input lowest wavelength data, the strain analysis branch identifies the vertex position, inflection point position and fluctuation interval range in the waveform corresponding to each time data as the waveform features at each time; According to the waveform features at the current time and the waveform features at the previous time, the difference values of the vertex positions and the inflection point positions are calculated, the fluctuation interval ranges at the current time and the previous time are compared, and the change amount of the fluctuation interval boundary is determined; The difference values of the vertex positions, the inflection point position difference values and the change amount of the fluctuation interval boundary are comprehensively calculated, the difference between the two waveforms is recorded, and the strain wavelength offset is obtained.

4. The method of claim 2, wherein, Through the temperature compensation branch, the position change trajectory of the light spot at different times is tracked, the position points on the position change trajectory are continuously recorded, the moving amplitude and direction of the position points are analyzed, and the temperature wavelength correction amount is obtained, including: Collect light spot position data at different times according to a preset time interval, and input the light spot position data into the temperature compensation branch in sequence; The temperature compensation branch identifies the spatial position of the light spot at each time as a position point, connects the position points at different times in time sequence to form a position change trajectory of the light spot; Select the position points at adjacent times in the position change trajectory, calculate the straight line distance between the position points at adjacent times as the moving amplitude, and determine the spatial offset direction of the position point at the next time relative to the position point at the previous time as the moving direction; Record the moving amplitude and the moving direction in a plurality of consecutive time periods, and calculate the moving amplitude and the offset amount corresponding to the moving direction to obtain the temperature wavelength correction amount.

5. The method of claim 1, wherein, The diffraction grating is used to perform secondary light splitting on the composite light output by the multi-core optical fiber, and the spectra of the two side cores are projected into non-overlapping areas in the photoelectric array to generate independent spectral data. The independent spectral data are used to block the coupling of the two-core light path through an air layer to enhance the strain sensitivity, including: The composite light outputted by the multi-core fiber is inputted into a diffraction grating, the diffraction grating is used for first light splitting, and a preliminary separated signal of different wavelengths is obtained, and the preliminary separated signal is secondly light split by the diffraction grating, and a light signal of different wavelengths with an expanded separation degree is obtained; A photoelectric array is arranged at the light signal output port of the diffraction grating, the photoelectric array is divided into two independent regions without overlapping, and the light signal after the second light splitting is projected into the two independent regions respectively; According to the projection of the light signal in the corresponding photoelectric array region, a respective spectrum image is formed, the spectrum image is converted into an electric signal through the photoelectric array, independent spectrum data of the two side cores is generated, and the change of the light signal of the two side cores affected by the strain is reflected through the independent spectrum data; An air layer is arranged between the two side cores of the multi-core fiber, and the air layer is used for preventing the light signals between the two side cores from being coupled with each other, so as to enhance the strain sensitive characteristic.

6. The method of claim 1, wherein, Based on the temperature decoupled strain demodulation value, a standardized strain characteristic signal is generated through photoelectric signal conversion, the characteristic signal is transmitted to a monitoring system, a dynamic distribution diagram of the axial strain of the multi-core fiber is reconstructed, and a temperature compensation state curve is synchronously displayed, including: The temperature decoupled strain demodulation value is inputted into a photoelectric conversion device, and the photoelectric conversion device is used for converting the light signal corresponding to the strain demodulation value into an electric signal; The converted electric signal is standardized, so that the amplitude and range of the signal are in a preset standard interval, and a standardized strain characteristic signal is generated; The strain characteristic signal is sent to the monitoring system through a data transmission line, and after receiving the signal, the monitoring system arranges the strain characteristic signals corresponding to different positions in the axial direction according to the axial position information of the multi-core fiber, and forms a dynamic distribution diagram of the axial strain of the multi-core fiber; The temperature wavelength correction data is extracted through the monitoring system, the change of the temperature wavelength correction data with time is presented in the form of a curve, and the dynamic distribution diagram is synchronously displayed on the monitoring interface.

7. A grating-demodulated multicore fiber strain and temperature decoupling system for performing the grating-demodulated multicore fiber strain and temperature decoupling method of any one of claims 1-6, wherein Including: An acquisition module is configured to acquire the lowest wavelength data of the spectrum of the two side cores of the multi-core fiber air layer, and record the spot position data formed by the second-order dispersion of the diffraction grating; A blocking module is configured to use the diffraction grating to perform second light splitting on the composite light outputted by the multi-core fiber, project the spectrum of the two side cores into non-overlapping regions of a photoelectric array, generate independent spectrum data, and block the coupling of the two-core light paths through the air layer based on the independent spectrum data to enhance the strain sensitive characteristic; A construction module is configured to construct a double-task analysis network with a parallel structure, perform continuous waveform comparison through a strain analysis branch of the double-task analysis network based on the lowest wavelength data, obtain a strain wavelength offset, perform dynamic trajectory tracking through a temperature compensation branch of the double-task analysis network based on the spot position data, and obtain a temperature wavelength correction. An adjusting module is configured to dynamically adjust shared layer weights of the dual-task analysis network based on the independent spectral data, in combination with time series data of the strain wavelength shift and amplitude fluctuation of the temperature wavelength correction, to generate temperature-decoupled strain demodulation values; A reconstruction module is configured to generate a standardized strain characteristic signal through photoelectric signal conversion based on the temperature-decoupled strain demodulation values, transmit the characteristic signal to a monitoring system, reconstruct an axial strain dynamic distribution map of the multicore optical fiber, and synchronously display a temperature compensation state curve.

8. An electronic device, comprising: The method comprises the steps of: a memory configured to store a computer program; a processor configured to execute the computer program to implement the steps of the method for decoupling strain and temperature of a grating-demodulated multicore optical fiber according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer program is stored in the computer-readable storage medium and is executable by the processor to implement the method for decoupling strain and temperature of a grating-demodulated multicore optical fiber according to any one of claims 1 to 6.

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