Multi-core fiber strain and temperature decoupling method and system for grating demodulation, electronic equipment and storage medium

Abstract

The invention provides a multi-core optical fiber strain and temperature decoupling method and system for grating demodulation, electronic equipment and a storage medium, and relates to the technical field of optical fiber sensing, and the method comprises the steps: obtaining the lowest wavelength data of the spectrum of fiber cores at two sides of an air layer of a multi-core optical fiber, and recording the position data of a light spot formed by the secondary dispersion of a diffraction grating at the same time. The diffraction grating is used for secondary light splitting of the composite light, independent spectrum data are generated, and two-core coupling is blocked through an air layer. A double-task analysis network is constructed, strain wavelength offset is obtained through strain branches, and temperature wavelength correction is obtained through temperature branches. Network weight is adjusted in combination with related data to generate a strain demodulation value of temperature decoupling, the strain demodulation value is converted into a standardized signal to be transmitted to a monitoring system, an axial strain dynamic distribution diagram is reconstructed, a temperature compensation curve is synchronously displayed, multi-core optical fiber strain and temperature accurate decoupling can be achieved, strain information can be dynamically obtained, and the distribution and compensation state can be synchronously displayed.

Description

Technical Field

[0001] The present application relates to the field of optical fiber sensing technology, and in particular to a method, system, electronic device, and storage medium for decoupling strain and temperature of a multi-core optical fiber using grating demodulation. Background Art

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

[0003] At present, the commonly used solution to meet this demand is to use a combined measurement method of a single-core fiber grating sensor and an infrared thermometer. The single-core fiber grating is used to sense the surface strain of the pipeline, and the infrared thermometer is used to simultaneously collect the ambient temperature near the pipeline. The temperature effect is then roughly corrected using a preset empirical formula.

[0004] However, this solution has obvious flaws: single-core fiber Bragg gratings are susceptible to cross-interference between temperature and strain, and it is difficult to achieve accurate decoupling of the two through empirical formulas alone; infrared thermometers are greatly affected by environmental radiation, dust and other factors, have high measurement errors, and cannot directly reflect the true temperature of the fluid inside the pipeline, resulting in insufficient accuracy in strain measurement results, making it difficult to meet the precise monitoring needs of high-temperature and high-pressure pipelines. Summary of the Invention

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

[0006] To solve the above technical problems, in a first aspect, the present application provides a multi-core optical fiber strain and temperature decoupling method using grating demodulation, comprising: Obtain the lowest wavelength data of the 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 secondary dispersion of the diffraction grating; The composite light output by the multi-core optical fiber is split twice using a diffraction grating, and the spectrum of the two cores is projected onto non-overlapping areas of the photoelectric array to generate independent spectrum data. Based on the independent spectrum data, the coupling between the two cores is blocked by an air layer to enhance the strain sensitivity. Constructing a parallel dual-task analysis network, performing continuous waveform comparison based on the minimum wavelength data through the strain analysis branch of the dual-task analysis network to obtain a strain wavelength offset, and performing dynamic trajectory tracking based on the light spot position data through the temperature compensation branch of the dual-task analysis network to obtain a temperature wavelength correction; Based on the independent spectral data, combined with the time series data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, dynamically adjust the shared layer weights of the dual-task analysis network to generate a temperature-decoupled strain demodulation value; Based on the temperature-decoupled strain demodulation value, a standardized strain characteristic signal is generated through photoelectric signal conversion, and the characteristic signal is transmitted to the monitoring system to reconstruct the dynamic distribution diagram of the axial strain of the multi-core optical fiber and synchronously display the temperature compensation status curve.

[0007] Optionally, a parallel dual-task analysis network is constructed. Based on the minimum wavelength data, continuous waveform comparison is performed through the strain analysis branch of the dual-task analysis network to obtain a strain wavelength offset. Based on the spot position data, dynamic trajectory tracking is performed through the temperature compensation branch of the dual-task analysis network to obtain a temperature wavelength correction, including: Building a dual-task analysis network with parallel processing paths, the network includes two parallel processing branches: a strain analysis branch and a temperature compensation branch, and the two branches share some initial processing units; Extracting the waveform feature corresponding to the lowest wavelength data through the strain analysis branch, continuously comparing the waveform feature at the current moment with the waveform feature at the previous moment, recording the difference between the two waveforms, and obtaining the strain wavelength offset; The temperature compensation branch is used to track the position change trajectory of the light spot at different times, continuously record the position points on the position change trajectory, analyze the movement amplitude and direction of the position points, and obtain the temperature wavelength correction amount.

[0008] Optionally, extracting the waveform feature corresponding to the lowest wavelength data through the strain analysis branch, continuously comparing the waveform feature at the current moment with the waveform feature at the previous moment, recording the difference between the two waveforms, and obtaining the strain wavelength offset includes: Dividing the minimum wavelength data into data segments according to preset time intervals, each data segment corresponds to the minimum wavelength data at a moment, and sequentially inputting the minimum wavelength data at each moment into the strain analysis branch; Based on the input minimum wavelength data, the strain analysis branch identifies the vertex position, inflection point position and fluctuation range in the waveform corresponding to the data at each moment as the waveform features at each moment; Calculating the difference between the corresponding vertex positions and the inflection point positions based on the waveform characteristics at the current moment and the waveform characteristics at the previous moment, and performing an overlapping comparison on the fluctuation ranges at the current moment and the previous moment to determine the change in the fluctuation range boundary; The difference in the vertex position, the difference in the inflection point position and the change in the fluctuation range boundary are comprehensively calculated, and the difference between the two waveforms is recorded to obtain the strain wavelength offset.

[0009] Optionally, the temperature compensation branch is used to track the position change trajectory of the light spot at different times, continuously record the position points on the position change trajectory, analyze the movement amplitude and direction of the position points, and obtain the temperature wavelength correction value, including: collecting light spot position data at different times according to preset time intervals, and inputting the light spot position data into the temperature compensation branch in sequence; Identify the spatial position of the light spot at each moment through the temperature compensation branch, mark it as a position point, and connect the position points at different moments in time sequence to form a position change trajectory of the light spot; Selecting position points at adjacent moments in the position change trajectory, calculating the straight-line distance between the position points at the adjacent moments as the movement amplitude, and determining the spatial offset direction of the position point at the latter moment relative to the position point at the previous moment as the movement direction; The movement amplitude and the movement direction in a plurality of consecutive time periods are recorded, and the movement amplitude and the offset corresponding to the movement direction are correlated and calculated to obtain a temperature wavelength correction amount.

[0010] Optionally, based on the independent spectral data, combined with the time series data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, dynamically adjusting the shared layer weights of the dual-task analysis network to generate a temperature-decoupled strain demodulation value, including: Acquiring the generated independent spectrum data, collecting time series data of the strain wavelength offset changing over time, and amplitude fluctuation data of the temperature wavelength correction amount; The independent spectrum data, time series data and amplitude fluctuation data are simultaneously input into the shared layer of the dual-task analysis network, and the optical signal characteristics of the fiber cores on both sides in the independent spectrum data are analyzed by the shared layer; Based on the optical signal characteristics, combined with the changing 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 strength of each processing unit in the shared layer is dynamically adjusted; By increasing the shared layer weight of the strain-related signal features in the optical signal features and decreasing the shared layer weight of the temperature-related signal features, an adjusted dual-task analysis network is obtained; The input data is processed by the adjusted dual-task analysis network to generate strain demodulation values ​​that eliminate the temperature influence, that is, temperature-decoupled strain demodulation values.

[0011] Optionally, a diffraction grating is used to perform secondary splitting on the composite light output by the multi-core optical fiber, and the spectrum of the two cores is projected onto non-overlapping areas of the photoelectric array to generate independent spectrum data. Based on the independent spectrum data, the coupling between the two core light paths is blocked by an air layer to enhance the strain sensitivity, including: Inputting the composite light output from the multi-core optical fiber into a diffraction grating, performing a first splitting on the diffraction grating to obtain preliminary separated signals of different wavelengths, and then performing a second splitting on the preliminary separated signals by the diffraction grating to obtain optical signals of different wavelengths with an expanded degree of separation; A photoelectric array is provided at the optical signal emission port of the diffraction grating, the photoelectric array is divided into two independent areas that do not overlap, and the optical signal after the secondary splitting is projected into the two independent areas respectively; Based on the projection of the optical signal within the corresponding photoelectric array area, respective spectral images are formed, and the photoelectric array converts the spectral images into electrical signals to generate independent spectral data for the fiber cores on both sides. The independent spectral data reflects the changes in the optical signals of the fiber cores on both sides affected by the strain; An air layer is provided between the two cores of the multi-core optical fiber, and the air layer prevents the optical signals between the two cores from coupling with each other, thereby enhancing the strain sensitivity.

[0012] Optionally, based on the temperature-decoupled strain demodulation value, a standardized strain characteristic signal is generated by photoelectric signal conversion, the characteristic signal is transmitted to a monitoring system, a dynamic distribution diagram of the axial strain of the multi-core optical fiber is reconstructed, and a temperature compensation state curve is synchronously displayed, including: Inputting the temperature-decoupled strain demodulation value into a photoelectric conversion device, and converting the optical signal corresponding to the strain demodulation value into an electrical signal through the photoelectric conversion device; Standardizing the converted electrical signal so that the amplitude and range of the signal are within a preset standard range, thereby generating a standardized strain characteristic signal; The strain characteristic signal is sent to a monitoring system via a data transmission line. After receiving the signal, the monitoring system arranges the strain characteristic signals corresponding to different positions axially 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; The temperature wavelength correction data is extracted through the monitoring system, and the change of the temperature wavelength correction data over time is presented in the form of a curve, and is synchronously displayed on the monitoring interface with the dynamic distribution diagram.

[0013] In a second aspect, the present application provides a multi-core optical fiber strain and temperature decoupling system with grating demodulation, comprising: An acquisition module is used to obtain the lowest wavelength data of the 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 secondary dispersion of the diffraction grating; A blocking module is used to perform secondary splitting of the composite light output by the multi-core optical fiber using a diffraction grating, project the spectrum of the two cores on each side into non-overlapping areas of the photoelectric array, generate independent spectral data, and block the coupling of the two core light paths through the air layer based on the independent spectral data to enhance the strain sensitivity; a construction module for constructing a parallel dual-task analysis network, performing continuous waveform comparison based on the minimum wavelength data through the strain analysis branch of the dual-task analysis network to obtain a strain wavelength offset, and performing dynamic trajectory tracking based on the light spot position data through the temperature compensation branch of the dual-task analysis network to obtain a temperature wavelength correction; an adjustment module for dynamically adjusting the shared layer weights of the dual-task analysis network based on the independent spectral data, in combination with the time series data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, to generate a temperature-decoupled strain demodulation value; A reconstruction module is used to generate a standardized strain characteristic signal through photoelectric signal conversion based on the strain demodulation value of the temperature decoupling, transmit the characteristic signal to the monitoring system, reconstruct the dynamic distribution diagram of the axial strain of the multi-core optical fiber, and synchronously display the temperature compensation status curve.

[0014] In a third aspect, the present application provides an electronic device, comprising: memory for storing computer programs; The processor is configured to implement the steps of the multi-core optical fiber strain and temperature decoupling method using grating demodulation as described in the first aspect above when executing the computer program.

[0015] In a fourth aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it can implement the steps of a multi-core optical fiber strain and temperature decoupling method with grating demodulation as described in the first aspect above.

[0016] The present application provides a method for decoupling strain and temperature of a multi-core optical fiber using grating demodulation. By obtaining the lowest wavelength data of the optical spectrum of the fiber cores on both sides of the air layer of the multi-core optical fiber and recording the light spot position data formed by the secondary dispersion of the diffraction grating, basic data support can be provided for the subsequent decoupling analysis of strain and temperature. The composite light output by the multi-core optical fiber is split twice by using the diffraction grating, and the optical spectrum of the fiber cores on both sides is projected onto non-overlapping areas of the photoelectric array to generate independent spectrum data. Based on the independent spectrum data, the coupling of the two-core optical paths is blocked by the air layer to enhance the strain sensitivity, thereby reducing optical path interference and improving the recognizability of the strain signal. By constructing a dual-task analysis network with a parallel structure, the strain analysis branch is used to obtain the strain signal based on the lowest wavelength data. The strain wavelength offset is obtained, and the temperature wavelength correction is obtained according to the temperature compensation branch based on the spot position data, which can realize the separate extraction of strain and temperature-related parameters; by dynamically adjusting the shared layer weights of the dual-task analysis network based on independent spectral data and combining the time series data of the strain wavelength offset with the amplitude fluctuation of the temperature wavelength correction, the temperature-decoupled strain demodulation value is generated, which can eliminate the interference of temperature on strain measurement and obtain accurate strain results; the strain demodulation value based on temperature decoupling is converted into a standardized strain characteristic signal through photoelectric signal conversion and transmitted to the monitoring system, reconstructing the dynamic distribution diagram of axial strain and synchronously displaying the temperature compensation status curve, which can intuitively present the pipeline strain status and temperature compensation effect, facilitating real-time monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 A schematic flow chart of a multi-core optical fiber strain and temperature decoupling method using grating demodulation provided in an embodiment of the present application; Figure 2 A schematic diagram illustrating a specific implementation of a multi-core optical fiber strain and temperature decoupling method using grating demodulation provided in an embodiment of the present application; Figure 3 A scenario diagram of a multi-core optical fiber strain and temperature decoupling method using grating demodulation provided in an embodiment of the present application; Figure 4 A schematic structural diagram of a multi-core optical fiber strain and temperature decoupling system with grating demodulation provided in an embodiment of the present application. DETAILED DESCRIPTION

[0019] For high-temperature, high-pressure pipeline monitoring, the existing single-core fiber Bragg grating (FBG) combined with infrared thermometers has significant limitations. First, single-core FBGs struggle to distinguish the effects of temperature and strain, and relying solely on empirical formula corrections cannot accurately separate the two, leading to strain measurement errors. Second, infrared thermometers are significantly affected by environmental interference, such as dust and radiation, resulting in inaccurate temperature measurements and an inability to directly reflect the true temperature of the fluid inside the pipeline. Ultimately, strain results are unreliable, making it difficult to meet pipeline safety monitoring requirements. The core of these issues lies in the inability of traditional solutions to effectively isolate the mutual interference between temperature and strain, and the lack of a direct and stable temperature measurement method.

[0020] In response to the above problems, this application proposes a method for decoupling strain and temperature of multi-core optical fibers using grating demodulation, which achieves precise monitoring through special optical signal processing and analysis strategies. This method first obtains the optical signal characteristics and spot position data of the cores on both sides of the multi-core optical fiber, uses a diffraction grating to separate the optical signals on both sides and generate independent data, while reducing signal interference through the air layer; then, with the help of a parallel dual-task analysis network, the strain-related wavelength changes and temperature-related spot trajectory changes are extracted respectively, and the strain results that eliminate the influence of temperature are generated by combining a dynamically adjusted analysis strategy. Finally, the strain distribution and temperature compensation status are intuitively displayed through the monitoring system. This solution solves the cross-interference problem of temperature and strain through the signal separation design of the multi-core optical fiber, and uses the spot position data to directly reflect the temperature change to avoid environmental interference, fundamentally improving the accuracy of strain measurement and meeting the needs of precise monitoring of high-temperature and high-pressure pipelines.

[0021] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. Obviously, the embodiments described are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making any creative efforts are within the scope of protection of the present application.

[0022] The core of this application is to provide a method for decoupling strain and temperature of a multi-core optical fiber using grating demodulation. A flow chart of a specific implementation method is shown in FIG. Figure 1 As shown, the method includes: S101, obtaining the lowest wavelength data of the spectrum of the fiber cores on both sides of the air layer of the multi-core optical fiber, and simultaneously recording the spot position data formed by the secondary dispersion of the diffraction grating; In the above steps, the air layer of a multi-core optical fiber refers to the air region between the two cores on both sides of the multi-core optical fiber, which is used to isolate the optical signals of the two cores on both sides; the spectrum of the two cores on both sides refers to the spectrum of the optical signals output by the two cores on both sides of the air layer in 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 spectrum of the two cores on both sides; the secondary dispersion of the diffraction grating refers to the dispersion phenomenon formed after the diffraction grating performs a second splitting of the optical signal; the light spot position data refers to the position coordinate data of the light spot formed in space after the secondary dispersion.

[0023] In the embodiment of the present application, first, by collecting the spectrum data of the cores on both sides of the air layer of the multi-core optical fiber, the lowest wavelength data is extracted. For example, in a high-temperature and high-pressure pipeline monitoring scenario, the multi-core optical fiber is attached to the surface of the pipeline, and the cores on both sides will output light signals containing different wavelengths. The spectrum detection device receives these light signals and forms a spectrum curve. The spectrum curve shows multiple fluctuating peaks and troughs. The wavelength corresponding to the trough is the lowest wavelength in the spectrum. By identifying the trough position of the spectrum curve at each moment and recording the wavelength value corresponding to the position, the lowest wavelength data of each core on both sides is obtained. Secondly, by recording the spot position data formed by the secondary dispersion of the diffraction grating. For example, in the above scenario, the light signal output by the multi-core optical fiber first enters the diffraction grating for the first splitting, separating the light signals of different wavelengths. These light signals are again split by the diffraction grating for the second splitting, that is, the secondary dispersion. The light spot formed is projected on the sensing surface of the preset position detection device. The device determines the X-axis and Y-axis coordinates of the center of the light spot on the sensing surface by sensing the illumination area of ​​the light spot. The coordinate information is recorded once every fixed time interval to form continuous light spot position data.

[0024] In a practical application, a high-temperature, high-pressure pipeline A at a chemical company requires long-term operational monitoring. A multi-core optical fiber B is fixedly attached to a key monitoring area on the outer surface of pipeline A. A spectrum detector C is connected to the output end of multi-core optical fiber B via a fiber optic connector to collect spectral data in real time. A diffraction grating D and a photoelectric array E are sequentially installed along the optical signal propagation path, and photoelectric array E is connected to a data recording device F. Spectrum detector C continuously receives spectral signals transmitted from both fiber cores, generating a spectral curve every 0.5 seconds and extracting the minimum wavelength corresponding to the trough. This minimum wavelength data for both fiber cores is stored in real time in device F. Simultaneously, a light spot, after secondary dispersion by diffraction grating D, is projected onto photoelectric array E, which detects the center coordinates of the light spot every 0.5 seconds and synchronously transmits the X and Y coordinate data to device F, forming a synchronized minimum wavelength data sequence and a light spot position data sequence.

[0025] In the overall solution of step S101 above, by synchronously acquiring the minimum wavelength data and spot position data of the fiber core spectra on both sides, an initial data source is provided for the subsequent analysis of strain and temperature changes. The synchronous recording of the two types of data ensures the temporal correlation of strain and temperature-related information in subsequent processing, laying a reliable data foundation for the decoupling analysis of the two.

[0026] S102, performing secondary splitting on the composite light output by the multi-core optical fiber using a diffraction grating, projecting the spectrum of the two cores onto non-overlapping areas of the optoelectronic array to generate independent spectrum data, and blocking the coupling between the two core optical paths through an air layer based on the independent spectrum data to enhance strain sensitivity; Optionally, step S102 may specifically include the following steps: S1021. Input the composite light output by the multi-core optical fiber into a diffraction grating, perform a first splitting on the diffraction grating to obtain preliminary separated signals of different wavelengths, and then perform a second splitting on the preliminary separated signals through the diffraction grating to obtain optical signals of different wavelengths with an expanded degree of separation. S1022: Setting a photoelectric array at the optical signal emission port of the diffraction grating, dividing the photoelectric array into two independent non-overlapping areas, and projecting the optical signal after the secondary splitting into the two independent areas respectively; S1023. Form respective spectral images based on the projection of the optical signals within the respective corresponding photoelectric array regions. Convert the spectral images into electrical signals through the photoelectric arrays to generate independent spectral data for the fiber cores on both sides. The independent spectral data reflect changes in the optical signals of the fiber cores on both sides affected by the strain. S1024. An air layer is provided between the fiber cores on both sides of the multi-core optical fiber, and the air layer is used to prevent the optical signals between the fiber cores on both sides from coupling with each other, so as to enhance the strain sensitivity characteristic.

[0027] In the above steps, composite light refers to a mixed light signal output by a multi-core optical fiber that contains light signals from both fiber cores; secondary splitting refers to the process of performing two splitting processes on a light signal through a diffraction grating; a preliminary separated signal refers to a light signal in which light signals of different wavelengths begin to separate after the first splitting; a light signal with an expanded degree of separation refers to a light signal in which light signals of different wavelengths are separated by a larger distance after the second splitting; a photoelectric array refers to a device for receiving light signals composed of multiple photoelectric sensing units; an independent area refers to two non-overlapping areas divided on the photoelectric array, which are used to receive light signals from both fiber cores respectively; a spectral image refers to an image reflecting the wavelength distribution of light signals formed within the photoelectric array area; independent spectral data refers to spectral data formed after the light signals of each fiber core on both sides are converted; an air layer refers to the air area between the fiber cores on both sides of the multi-core optical fiber; optical path coupling refers to the phenomenon of mutual transmission of light signals between the fiber cores on both sides; and strain sensitivity refers to the ability of the fiber core light signal to respond to changes in pipeline strain.

[0028] In the embodiment of the present application, first, in step S1021, the composite light output by the multi-core optical fiber is input into a diffraction grating, where it undergoes a first splitting by the diffraction grating to obtain preliminary separated signals of different wavelengths. The preliminary separated signals are then subjected to a second splitting by the diffraction grating to obtain optical signals of different wavelengths with a greater degree of separation. For example, in a high-temperature and high-pressure pipeline monitoring scenario, after the composite light output by the multi-core optical fiber enters the diffraction grating, the first splitting causes the different wavelength components in the optical signal to be refracted at different angles, forming closely spaced optical signal beams. These preliminarily separated optical signal beams then pass through the diffraction grating again, where the wavelength spacing is further expanded after the second splitting, increasing the distance between the optical signal beams of different wavelengths and forming optical signal beams that are easier to distinguish.

[0029] Next, in step S1022, a photoelectric array is installed at the optical signal output port of the diffraction grating, dividing the photoelectric array into two independent, non-overlapping regions. The optical signal after secondary splitting is then projected into the two independent regions. For example, in the above scenario, the photoelectric array is fixedly installed on one side of the diffraction grating outputting the optical signal. The array is divided into two independent regions on the left and right sides along the horizontal axis using preset region division parameters. Each region corresponds to the optical signal of a fiber core. After secondary splitting, the optical signal beam of the left fiber core is precisely projected into the left region, and the optical signal beam of the right fiber core is projected into the right region, with no overlap at the edges of the two regions.

[0030] Next, in step S1023, based on the projection of the optical signal within the corresponding photoelectric array region, a respective spectral image is formed. The photoelectric array converts the spectral image into an electrical signal, generating independent spectral data for each of the two fiber cores. The independent spectral data reflects the changes in the optical signals of the two fiber cores affected by strain. For example, in the above scenario, the optical signal of the left fiber core forms a spectral image composed of different brightness points in the left region of the photoelectric array. Different brightness points correspond to optical signal intensities of different wavelengths. The optical signal of the right fiber core forms a similar spectral image in the right region. Each sensing unit of the photoelectric array converts the received optical signal intensity into a corresponding electrical signal value. After integration, the independent spectral data of the left and right fiber cores are formed. When the pipeline strain changes and causes the fiber core to deform, the wavelength distribution characteristics of these data will change accordingly.

[0031] Finally, in step S1024, an air layer is provided between the two cores of the multi-core optical fiber. This air layer prevents the optical signals between the two cores from coupling with each other, thereby enhancing strain sensitivity. For example, in the above scenario, during production of the multi-core optical fiber, a specific thickness of air layer is reserved between the two cores through precision machining. The optical properties of the air layer differ significantly from those of the cores, blocking the transmission path of the optical signal between the two cores. This causes the optical signal in the left core to propagate only along its own path, while the optical signal in the right core also propagates independently, avoiding mutual interference. This makes the optical signal more susceptible to strain and produces recognizable changes.

[0032] In actual applications, when a chemical company performs strain monitoring on a key weld area of ​​a high-temperature and high-pressure pipeline A, it fixes a multi-core optical fiber B near the weld along the pipeline axis. The composite light output by the multi-core optical fiber B is introduced into the diffraction grating C through an optical lens. After the first splitting, the wavelength components of the light signal between 500 and 800 nm are initially separated to form light signal beams with an interval of about 1 mm. These light signal beams are split again by the diffraction grating C for a second splitting, and the separation interval is expanded to 5 mm. A photoelectric array D is installed 10 cm away from the light signal outlet of the diffraction grating C to divide it into left and right beams. There are two independent 10×10mm areas on the right and left. The optical signal of the left fiber core is projected to the left area after secondary splitting, and the optical signal of the right fiber core is projected to the right area. The sensing unit of the photoelectric array D converts the spectral images of the left and right areas into electrical signals, which are processed by the data collector to generate and store independent spectral data of the left and right fiber cores. At the same time, the 0.5mm thick air layer between the fiber cores on both sides of the multi-core optical fiber B effectively prevents the coupling of optical signals. When pipeline A produces a small strain due to internal pressure fluctuations, the wavelength peak position of the independent spectral data is significantly offset, accurately reflecting the strain change.

[0033] In the overall solution of step S102 above, the separation effect of optical signals of different wavelengths is significantly improved through secondary splitting, making the optical signals of the fiber cores on both sides easier to distinguish; the division of independent areas avoids mutual interference of optical signals during the reception process, 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 fiber cores on both sides, reduces irrelevant signal interference, makes the optical signal more directly sensitive to pipeline strain, and overall improves the recognizability and reliability of the strain signal, providing a high-quality signal foundation for subsequent strain and temperature decoupling analysis.

[0034] The embodiment of the present application provides a schematic diagram of a method for decoupling strain and temperature of a multi-core optical fiber using grating demodulation, as shown in FIG. Figure 2 As shown, including the following: S103: Constructing a parallel dual-task analysis network; performing continuous waveform comparison based on the minimum wavelength data through the strain analysis branch of the dual-task analysis network to obtain a strain wavelength offset; and performing dynamic trajectory tracking based on the light spot position data through the temperature compensation branch of the dual-task analysis network to obtain a temperature wavelength correction; Optionally, step S103 may specifically include the following steps: S1031. Building a dual-task analysis network with parallel processing paths, wherein the network includes two parallel processing branches: a strain analysis branch and a temperature compensation branch, and the two branches share some initial processing units; S1032. Extracting the waveform feature corresponding to the lowest wavelength data through the strain analysis branch, continuously comparing the waveform feature at the current moment with the waveform feature at the previous moment, recording the difference between the two waveforms, and obtaining a strain wavelength offset; Among them, step S1032 may specifically include the following processes: dividing the minimum wavelength data into data segments according to preset time intervals, 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; based on the input minimum wavelength data, identifying the vertex position, inflection point position and fluctuation range in the waveform corresponding to the data at each moment through the strain analysis branch as the waveform feature of each moment; according to the waveform feature at the current moment and the waveform feature at the previous moment, calculating the difference between the corresponding vertex position and the difference between the inflection point position, overlapping and comparing the fluctuation range range at the current moment and the previous moment, and determining the change in the fluctuation range boundary; comprehensively calculating the difference in the vertex position, the difference in the inflection point position and the change in the fluctuation range boundary, recording the difference between the two waveforms, and obtaining the strain wavelength offset.

[0035] S1033. Track the position change trajectory of the light spot at different times through the temperature compensation branch, continuously record the position points on the position change trajectory, analyze the movement amplitude and direction of the position points, and obtain the temperature wavelength correction amount.

[0036] Among them, step S1033 may specifically include the following processes: collecting light spot position data at different moments at preset time intervals, and inputting the light spot position data into the temperature compensation branch in sequence; identifying the spatial position of the light spot at each moment through the temperature compensation branch, marking it as a position point, and connecting the position points at different moments in chronological order to form a position change trajectory of the light spot; selecting position points at adjacent moments in the position change trajectory, calculating the straight-line distance between the position points at adjacent moments as the movement amplitude, and determining the spatial offset direction of the position point at the latter moment relative to the position point at the previous moment as the movement direction; recording the movement amplitude and the movement direction in multiple consecutive time periods, and correlating the movement amplitude with the offset corresponding to the movement direction to obtain a temperature wavelength correction amount.

[0037] In the above steps, the parallel-structured dual-task analysis network refers to an analysis system with two paths for simultaneously processing different tasks, which are used to process strain and temperature-related data respectively; the strain analysis branch is a path in the dual-task analysis network that specifically processes strain-related data; the temperature compensation branch is a path in the dual-task analysis network that specifically processes temperature-related data; the shared initial processing unit refers to the early data processing component used by the strain analysis branch and the temperature compensation branch; the waveform characteristics refer to the representative characteristics of the waveform formed by the lowest wavelength data, including the vertex position, inflection point position and fluctuation range; the vertex position refers to the position corresponding to the peak or trough in the waveform; the inflection point position refers to the position where the change trend in the waveform changes; the fluctuation range refers to the fluctuation range of the waveform within a certain wavelength range; the strain wavelength offset refers to the wavelength position change caused by strain; the position change trajectory refers to the path formed by connecting the positions of the light spot at different times in chronological order; the movement amplitude refers to the distance between the positions of the light spot at adjacent times; the movement direction refers to the spatial offset direction of the light spot at the next moment relative to the light spot at the previous moment; the temperature wavelength correction amount refers to the amount of wavelength correction required due to temperature change.

[0038] In the embodiment of the present application, step S1031 is first used to establish a dual-task analysis network with parallel processing paths. This network includes two parallel processing branches: a strain analysis branch and a temperature compensation branch. These two branches share some initial processing units. For example, in a high-temperature, high-pressure pipeline monitoring scenario, the dual-task analysis network established includes two parallel processing paths: one path is a strain analysis branch that specifically processes the lowest wavelength data, and the other is a temperature compensation branch that specifically processes the spot position data. In the initial stage of data processing, these two branches share processing components such as data reception and format conversion to improve data processing efficiency.

[0039] Secondly, through step S1032, the minimum wavelength data is divided into data segments according to preset time intervals, 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; based on the input minimum wavelength data, the vertex position, inflection point position and fluctuation range in the waveform corresponding to the data at each moment are identified through the strain analysis branch as the waveform characteristics of each moment; based on the waveform characteristics of the current moment and the waveform characteristics of the previous moment, the difference between the corresponding vertex position and the difference between the inflection point position are calculated, and the fluctuation range range of the current moment and the previous moment are overlapped and compared to determine the change in the fluctuation range boundary; the difference in the vertex position, the difference in the inflection point position and the change in the fluctuation range boundary are comprehensively calculated, and the difference between the two waveforms is recorded to obtain the strain wavelength offset. For example, in the above scenario, the lowest wavelength data is divided into multiple data segments at 0.5-second intervals. Each data segment corresponds to the waveform at a specific moment. After these data are sequentially input into the strain analysis branch, the branch identifies that the peak of the waveform at a certain moment is at 600nm, the inflection points are at 590nm and 610nm, and the fluctuation range is 580-620nm. The corresponding peak at the previous moment is 599nm, the inflection points are at 589nm and 609nm, and the range is 579-619nm. The calculated difference in the vertex is 1nm, the difference in the inflection point is 1nm, and the change in the interval boundary is 1nm. Combining these data, the strain wavelength offset for that time period is obtained.

[0040] Finally, through step S1033, the light spot position data at different moments are collected at preset time intervals, and the light spot position data are sequentially input into the temperature compensation branch; the spatial position of the light spot at each moment is identified through the temperature compensation branch, marked as a position point, and the position points at different moments are connected in chronological order to form a position change trajectory of the light spot; the position points at adjacent moments in the position change trajectory are selected, the straight-line distance between the position points at adjacent moments is calculated as the movement amplitude, and the spatial offset direction of the position point at the latter moment relative to the position point at the previous moment is determined as the movement direction; the movement amplitude and movement direction in multiple consecutive time periods are recorded, and the movement amplitude is correlated with the offset of the corresponding movement direction to obtain the temperature wavelength correction amount. For example, in the above scenario, the light spot position data is collected at intervals of 0.5 seconds to obtain the coordinates of the position at time t1 (10, 20), at time t2 (12, 21), and at time t3 (14, 22). After inputting the temperature compensation branch, the branch marks these position points and connects them into a trajectory, and calculates the straight-line distance from t1 to t2 as follows: , the direction is upper right, the distance from t2 to t3 is also about 2.24, the direction is upper right. After recording these amplitudes and directions, the temperature wavelength correction amount is obtained by correlation calculation.

[0041] In a real-world application, an energy company established a dual-task analysis network B for data processing during the long-term operation monitoring of a high-temperature, high-pressure pipeline A. This network comprises a parallel strain analysis branch C and a temperature compensation branch D. Both branches share initial processing units E, such as the data receiving module and format conversion module, to reduce redundant computations. During monitoring, a multi-core optical fiber F on the surface of pipeline A collects the lowest wavelength data from both fiber cores every 0.5 seconds. This data is divided into time segments, such as t0, t1, t2, ..., tn, and is sequentially input into the strain analysis branch C. Branch C performs waveform analysis on each data segment. For example, it identifies that the trough vertex of the waveform at time t5 is located at 550nm, the two inflection points are at 545nm and 555nm, and the fluctuation range is 540-560nm. The corresponding vertex at time t4 is at 548nm, the inflection points are at 543nm and 553nm, and the range is 538-558nm. The difference in vertex position is 2nm, the difference in inflection point is 2nm, and the change in interval boundary is 2nm. These differences are combined to obtain the strain wavelength offset from t4 to t5. At the same time, the position coordinates of the secondary dispersion spot generated by the diffraction grating G are recorded by the photoelectric array H every 0.5 seconds, and the position points such as t0: (8, 10), t1: (9, 11), t2: (10, 12) ... t5: (13, 15) are obtained. After these data are input into the temperature compensation branch D, the branch connects the position points into a continuous trajectory in chronological order, and calculates the straight-line distance from t4 (12, 14) to t5 (13, 15) as The moving direction is upper right. After continuously recording the amplitude and direction of multiple time periods, the temperature wavelength correction of each time period is obtained by correlation calculation. The strain wavelength offset and temperature wavelength correction are synchronously stored in database I to provide data support for subsequent decoupling processing.

[0042] In the overall solution of step S103 above, by building a parallel dual-task analysis network, synchronous parallel processing of strain and temperature-related data is achieved, avoiding the efficiency bottleneck of single-path processing and improving the timeliness of data processing. The strain analysis branch accurately captures the subtle wavelength changes caused by strain through continuous comparison and difference calculation of waveform features, providing reliable parameters for subsequent strain quantification. The temperature compensation branch effectively extracts temperature-related position change characteristics through dynamic tracking of the light spot trajectory and amplitude direction analysis, providing a direct basis for temperature influence correction. The shared initial processing unit streamlines the data preprocessing process, reduces resource consumption, and overall improves the professionalism, accuracy and efficiency of data processing, laying a key parameter foundation for the precise decoupling of strain and temperature.

[0043] S104, based on the independent spectral data, combined with the time series data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, dynamically adjusting the shared layer weights of the dual-task analysis network to generate a temperature-decoupled strain demodulation value; Optionally, step S104 may specifically include the following steps: S1041, acquiring the generated independent spectrum data, collecting time series data of the strain wavelength offset changing over time, and amplitude fluctuation data of the temperature wavelength correction; S1042, inputting the independent spectrum data, time series data, and amplitude fluctuation data simultaneously into the shared layer of the dual-task analysis network, and analyzing optical signal characteristics of the fiber cores on both sides of the independent spectrum data through the shared layer; S1043. Dynamically adjust the intensity of each processing unit in the shared layer based on the optical signal characteristics, in combination with the changing 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; S1044, obtaining an adjusted dual-task analysis network by increasing the shared layer weight of the strain-related signal features in the optical signal features and decreasing the shared layer weight of the temperature-related signal features; S1045 , processing the input data through the adjusted dual-task analysis network to generate a strain demodulation value that eliminates the temperature influence, that is, a temperature-decoupled strain demodulation value.

[0044] In the above steps, independent spectral data refers to the spectral data formed after the optical signals of the respective fiber cores on both sides of the multi-core optical fiber are converted, which is used to reflect the changes in the optical signals of the fiber cores on both sides affected by external factors; the time series data of the strain wavelength offset refers to the data sequence formed by the strain wavelength offset arranged in sequence over time, 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 over time; the shared layer of the dual-task analysis network refers to the intermediate data processing layer used by the strain analysis branch and the temperature compensation branch, which is used to uniformly preprocess and extract features from the input data; the shared layer weight refers to the intensity parameter of the effect of each processing unit in the shared layer on different signal features. The larger the weight, the more significant the impact on the corresponding signal feature; the optical signal feature refers to the optical signal attribute contained in the independent spectral data that can reflect the influence of strain or temperature; the intensity of the processing unit refers to the processing strength of each processing component in the shared layer on the data; the temperature-decoupled strain demodulation value refers to the demodulation result value that only reflects the strain change after eliminating the temperature influence.

[0045] In this embodiment, step S1041 is first used to obtain the generated independent spectral data, collect time series data on the strain wavelength offset over time, and collect data on the amplitude fluctuation of the temperature wavelength correction. For example, in a high-temperature, high-pressure pipeline monitoring scenario, independent spectral data for both fiber cores is retrieved from the data storage unit. The strain wavelength offset values ​​recorded every 0.5 seconds over the past 10 minutes, such as 0.2nm, 0.3nm, 0.25nm, etc., are collected to form a time series. Furthermore, data on the amplitude fluctuation of the temperature wavelength correction value over the same period, such as 0.1nm to 0.15nm, 0.12nm to 0.18nm, etc., are collected.

[0046] Next, in step S1042, the independent spectral data, time series data, and amplitude fluctuation data are simultaneously input into the shared layer of the dual-task analysis network. The shared layer then analyzes the optical signal characteristics of the fiber cores on both sides of the independent spectral data. For example, in the scenario described above, after the three types of data are synchronously input into the shared layer, the shared layer analyzes the independent spectral data and identifies wavelength drift characteristics related to pipeline strain, such as the linear shift of wavelength with pressure changes, and temperature-related wavelength fluctuation characteristics, such as the overall shift of wavelength with increasing temperature.

[0047] Next, in step S1043, based on the optical signal characteristics, combined with the changing 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 strength of each processing unit in the shared layer is dynamically adjusted. For example, in the above scenario, based on the identified optical signal characteristics, it is found that the strain wavelength offset in the time series exhibits a periodic increasing trend, such as increasing with the cyclic fluctuation of pipeline pressure, while the fluctuation range of the temperature wavelength correction is stable between 0.1 and 0.2 nm. Based on this, the shared layer strengthens the strength of processing units sensitive to strain-related characteristics and weakens the strength of processing units sensitive to temperature-related characteristics.

[0048] Then, in step S1044, the shared layer weights of the optical signal features related to strain are increased, while the shared layer weights of the features related to temperature are decreased, resulting in an adjusted dual-task analysis network. For example, in the above scenario, the weights of the processing units in the shared layer that are sensitive to time series changes in the strain wavelength offset are adjusted from 0.3 to 0.6, while the weights of the processing units that are sensitive to fluctuations in the amplitude of the temperature wavelength correction are decreased from 0.4 to 0.1, allowing the network to focus more on capturing strain-related signals.

[0049] Finally, in step S1045, the adjusted dual-task analysis network processes the input data to generate temperature-decoupled strain demodulation values. For example, in the scenario described above, the adjusted network processes the newly input independent spectral data, the latest time series data, and the amplitude fluctuation data, filtering out wavelength variations caused by temperature, and outputting a demodulated value that reflects only the pipeline strain.

[0050] In a practical application, a chemical company's monitoring system for high-temperature, high-pressure pipeline A uses data processing module B to acquire independent spectral data generated by multi-core optical fiber C at 0.5-second intervals. The spectrum ranges from 500-600 nm for the left core and 550-650 nm for the right core. Simultaneously, it collects time series data for strain wavelength offsets over the past 30 minutes, such as t1: 0.2 nm, t2: 0.22 nm, and t360: 0.5 nm, as well as amplitude fluctuations of temperature-wavelength corrections, such as those ranging from 0.1 to 0.18 nm. This data is synchronously fed into shared layer E of dual-task analysis network D. Shared layer E analyzes the independent spectra, revealing a stable offset at 550 nm for the left core that varies with pipeline pressure, and a fluctuating offset at 600 nm for the right core that varies with ambient temperature. Taking into account the increasing trend of strain offset in the time series, which increases by approximately 0.05 nm every 5 minutes and the stable fluctuation range of the temperature correction, the shared layer E adjusts the weight of processing unit F, which is sensitive to strain features, from 0.25 to 0.7, and the weight of processing unit G, which is sensitive to temperature features, from 0.3 to 0.08. After processing the newly input data at time t361, the adjusted network generates a temperature-decoupled strain demodulation value of 132 με, which eliminates temperature interference and reflects only the actual strain state of the pipeline.

[0051] In the overall solution of step S104 above, by integrating independent spectral data, strain time series, and temperature fluctuation data, a multi-dimensional basis is provided for network weight adjustment. Dynamic adjustment of shared layer weights enhances strain-related signals and suppresses temperature-related signals, allowing the network to focus more accurately on strain characteristics. The resulting temperature-decoupled strain demodulation value effectively eliminates the interference of temperature factors, improves the purity and accuracy of strain measurement, provides reliable core data for subsequent strain monitoring and analysis, and further improves the decoupling mechanism of strain and temperature.

[0052] S105 , based on the temperature-decoupled strain demodulation value, generate a standardized strain characteristic signal through photoelectric signal conversion, transmit the characteristic signal to the monitoring system, reconstruct the dynamic distribution diagram of the axial strain of the multi-core optical fiber, and synchronously display the temperature compensation status curve.

[0053] Optionally, step S105 may specifically include the following steps: S1051, inputting the temperature-decoupled strain demodulation value into a photoelectric conversion device, and converting the optical signal corresponding to the strain demodulation value into an electrical signal through the photoelectric conversion device; S1052: performing standardization processing on the converted electrical signal so that the amplitude and range of the signal are within a preset standard range, thereby generating a standardized strain characteristic signal; S1053. Sending the strain characteristic signal to a monitoring system via a data transmission line. After receiving the signal, the monitoring system arranges the strain characteristic signals corresponding to different positions axially 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. S1054. Extracting temperature wavelength correction data through the monitoring system, presenting the change of the temperature wavelength correction data over time in the form of a curve, and displaying it on the monitoring interface synchronously with the dynamic distribution diagram.

[0054] In the above steps, the temperature-decoupled strain demodulation value refers to the demodulation result value that only reflects the strain change after the temperature influence is eliminated; the photoelectric conversion device refers to a device that converts an optical signal into an electrical signal, which is used to realize the conversion of optical signal to electrical signal; standardization processing refers to the processing process of adjusting the amplitude and range of the electrical signal to make it conform to the preset standard range; the standardized strain characteristic signal refers to the strain-related electrical signal whose amplitude and range are within the standard range after standardization processing; the data transmission line refers to the physical or wireless transmission channel used to transmit signals; the monitoring system refers to the system that receives and processes signals and displays monitoring results; the axial position information of the multi-core optical fiber refers to the coordinate information of the multi-core optical fiber at different axial positions along the pipeline; the axial strain dynamic distribution diagram refers to the strain distribution image arranged according to the axial position of the multi-core optical fiber, which can dynamically reflect the strain state at different positions; the temperature wavelength correction data refers to the wavelength-related data used to correct the temperature influence; the temperature compensation state curve refers to the curve reflecting the change of temperature wavelength correction data over time.

[0055] In this embodiment of the present application, first, in step S1051, the temperature-decoupled strain demodulated value is input into a photoelectric conversion device, which then converts the optical signal corresponding to the strain demodulated value into an electrical signal. For example, in a high-temperature, high-pressure pipeline monitoring scenario, the temperature-decoupled strain demodulated value is transmitted to the photoelectric conversion device in the form of an optical signal. The photoelectric sensing element within the device converts the intensity of the optical signal into a corresponding voltage signal, such that higher light intensity corresponds to higher voltage, thus achieving optical-to-electrical signal conversion.

[0056] Next, in step S1052, the converted electrical signal is normalized to bring its amplitude and range within a preset standard range, generating a standardized strain signature signal. For example, in the scenario described above, the converted electrical signal voltage range is between 0.5-3V. Through normalization, it is adjusted to the preset standard range of 1-5V, ensuring that the signal at different times and locations has a uniform amplitude reference, generating a standardized strain signature signal.

[0057] Next, in step S1053, the strain characteristic signal is sent to the monitoring system via the data transmission line. After receiving the signal, the monitoring system arranges the strain characteristic signals corresponding to different positions along the axial direction based on the axial position information of the multi-core optical fiber, forming a dynamic distribution map of the multi-core optical fiber's axial strain. For example, in the above scenario, the standardized strain characteristic signal is sent to the monitoring system via a wired transmission line. The system has built-in coordinates of the multi-core optical fiber's position along the pipeline axial direction, such as 0m, 0.5m, 1m, and so on. The strain signal value corresponding to each position is mapped to an image in the order of the coordinates, forming a dynamic distribution map that updates over time and intuitively displays the strain magnitude at different positions.

[0058] Finally, in step S1054, the monitoring system extracts the temperature-wavelength correction data, presents its temporal changes in a curve, and displays it on the monitoring interface in sync with the dynamic distribution graph. For example, in the scenario described above, the monitoring system extracts the contemporaneous temperature-wavelength correction data from the database and plots a curve with time as the horizontal axis and the correction amount as the vertical axis. This curve is then displayed in separate areas on the same interface as the axial strain dynamic distribution graph, allowing the operator to simultaneously observe the strain distribution and temperature compensation effects.

[0059] In a real-world application, an energy company monitors high-temperature, high-pressure pipeline A. Temperature-decoupled strain demodulation values, such as 120 με and 125 με, are input to photoelectric conversion device B, which converts the corresponding optical signals into electrical signals ranging from 0.8 to 2.5 V. Signal processing module C standardizes the electrical signals to a standard range of 1 to 5 V, generating standardized strain signature signals. These signals are then transmitted via optical fiber transmission line D to monitoring system E. Based on the axial position of multi-core optical fiber F along the pipeline, from 0 to 10 m, with one monitoring point every 0.5 m, system E arranges the strain signals at each location and generates a real-time dynamic axial strain distribution map on the left side of the interface. Red areas indicate high strain zones. Simultaneously, system E extracts temperature wavelength correction data, such as 0.12 nm and 0.15 nm, and plots a temperature compensation status curve on the right side of the interface. The horizontal axis represents the monitoring time (0 to 60 minutes) and the vertical axis represents the correction value. This curve is updated synchronously with the dynamic distribution map, facilitating comprehensive assessment of pipeline status by the operator.

[0060] In the overall solution of step S105 above, the form conversion of the strain signal is achieved through photoelectric conversion, providing an adaptive signal type for subsequent transmission and processing; standardized processing unifies the signal format to ensure the comparability of different data and system compatibility; the dynamic distribution diagram intuitively presents the axial strain distribution state of the multi-core optical fiber, facilitating the rapid identification of high-strain areas; the synchronous display of the temperature compensation state curve provides a reference basis for the reliability of the strain data, and overall improves the intuitiveness, readability and practicality of the monitoring results, providing clear visual support for the safety monitoring of high-temperature and high-pressure pipelines.

[0061] The following is a complete embodiment of steps S101 to S105: 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. The multi-core optical fiber B is attached to the key area along the pipeline axis. The air layer inside it isolates the fiber cores on both sides. The output end is sequentially provided with a diffraction grating C, a photoelectric array D, and a data processing unit E. The monitoring system F is connected to the processing unit through a line. During data acquisition, the spectrum detector obtains the lowest wavelength data of the spectrum of the fiber cores on both sides, which is about 550nm on the left and about 600nm on the right. The photoelectric array Record the initial position of the diffraction grating secondary dispersion spot 10,15. In the signal separation stage, the diffraction grating splits the composite light twice. After the first separation, the second splitting is performed to expand the interval. The left spectrum is projected onto the left area of ​​the photoelectric array. The row sensing unit generates independent spectral data from the right to the right area (6-10 row sensing units). The air layer blocks the optical path coupling to ensure signal independence. A dual-task analysis network is built in the data processing stage. The strain analysis branch divides the data into 0.5 seconds, identifies the waveform vertices such as the 550nm trough, the inflection points 545nm and 555nm, and the intervals , and the difference is calculated by comparing with the previous moment to get the strain wavelength offset; the temperature compensation branch tracks the change of the spot position and calculates the time t1 time Connect them into a trajectory and calculate the movement amplitude of adjacent points. During dynamic adjustment, the network sharing layer receives data and analyzes the characteristics, adjusts the weight of the strain sensitive unit from 0.3 to 0.6, and the temperature sensitive unit from 0.4 to 0.1, and generates the temperature decoupled strain demodulation value as follows In the result display stage, the photoelectric conversion device converts the demodulated value into The electrical signal is normalized to The characteristic signal is transmitted to the monitoring system F, and the system is based on the axial position of the optical fiber. A dynamic distribution diagram is drawn at each measuring point of 0.5m, and high strain areas are marked in red. The temperature correction data is extracted simultaneously to draw a time-correction curve with a horizontal axis of 0-60 minutes and a vertical axis , to achieve real-time monitoring.

[0062] The multi-core optical fiber strain and temperature decoupling method provided by the grating demodulation in this application provides two-dimensional basic data support for strain and temperature decoupling by synchronously collecting the minimum wavelength data and spot position data of the fiber cores on both sides of the multi-core optical fiber. The secondary splitting and independent area projection design, combined with the air layer blocking the optical path coupling, effectively reduces signal interference and significantly enhances the independence and sensitivity of the strain signal. The parallel dual-task analysis network realizes the synchronous extraction of strain and temperature related parameters, the continuous waveform comparison accurately captures the strain wavelength offset characteristics, and the dynamic trajectory tracking effectively identifies the temperature wavelength correction law. By dynamically adjusting the shared layer weight, strengthening the strain signal characteristics and weakening the temperature interference, the temperature-decoupled strain demodulation value is successfully generated, eliminating the cross-influence of temperature on the measurement results. Finally, through standardized signal conversion and visual display, the dynamic distribution of axial strain and the temperature compensation state are intuitively presented, which improves the accuracy, stability and intuitiveness of strain measurement as a whole, and provides reliable technical support for structural strain monitoring in complex environments such as high temperature and high pressure.

[0063] Figure 4 A schematic structural diagram of a specific implementation of a multi-core optical fiber strain and temperature decoupling system for grating demodulation provided in an embodiment of the present application, with reference to Figure 4 , the system may include: An acquisition module 41 is used to obtain the lowest wavelength data of the 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 secondary dispersion of the diffraction grating; A blocking module 42 is configured to perform secondary splitting of the composite light output by the multi-core optical fiber using a diffraction grating, project the spectrum of the two cores on each side into non-overlapping areas of the photoelectric array, generate independent spectrum data, and block the coupling of the two core optical paths through an air layer based on the independent spectrum data to enhance the strain sensitivity. A construction module 43 is configured to construct a parallel dual-task analysis network, perform continuous waveform comparison based on the minimum wavelength data through the strain analysis branch of the dual-task analysis network to obtain a strain wavelength offset, and perform dynamic trajectory tracking based on the spot position data through the temperature compensation branch of the dual-task analysis network to obtain a temperature wavelength correction. an adjustment module 44 for dynamically adjusting the shared layer weights of the dual-task analysis network based on the independent spectral data, in combination with the time series data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, to generate a temperature-decoupled strain demodulation value; The reconstruction module 45 is used to generate a standardized strain characteristic signal through photoelectric signal conversion based on the strain demodulation value of the temperature decoupling, transmit the characteristic signal to the monitoring system, reconstruct the dynamic distribution diagram of the axial strain of the multi-core optical fiber, and synchronously display the temperature compensation status curve.

[0064] The grating-demodulated multi-core optical fiber strain and temperature decoupling system of the embodiment of the present application is used to implement the aforementioned grating-demodulated multi-core optical fiber strain and temperature decoupling method. Therefore, the specific implementation method of the grating-demodulated multi-core optical fiber strain and temperature decoupling system can be seen in the embodiment part of the grating-demodulated multi-core optical fiber strain and temperature decoupling method in the previous text. Its specific implementation method can refer to the description of the corresponding embodiments of each part, and will not be repeated here.

[0065] The present application also provides an electronic device, comprising: a memory for storing a computer program; and a processor for implementing the steps of any of the above-mentioned methods for decoupling strain and temperature of multi-core optical fibers using grating demodulation when executing the computer program.

[0066] The present application also provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of any of the above-mentioned methods for decoupling strain and temperature of a multi-core optical fiber using grating demodulation are implemented.

[0067] In an exemplary embodiment, the computer-readable storage medium may include, but is not limited to, various media capable of storing computer programs, such as a USB flash drive, a read-only memory, a random access memory, a mobile hard disk, a magnetic disk, or an optical disk.

[0068] An embodiment of the present invention further provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the steps in any of the above-mentioned embodiments of the multi-core optical fiber strain and temperature decoupling method for grating demodulation are implemented.

[0069] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0070] The above is a detailed introduction to the multi-core optical fiber strain and temperature decoupling method, system, electronic device and storage medium for grating demodulation provided by the present application. This article uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the present application.

Claims

1. A multi-core optical fiber strain and temperature decoupling method using grating demodulation, characterized in that: include: Obtain the lowest wavelength data of the 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 secondary dispersion of the diffraction grating; The composite light output by the multi-core optical fiber is split twice using a diffraction grating, and the spectrum of the two cores is projected onto non-overlapping areas of the photoelectric array to generate independent spectrum data. Based on the independent spectrum data, the coupling between the two cores is blocked by an air layer to enhance the strain sensitivity. Constructing a parallel dual-task analysis network, performing continuous waveform comparison based on the minimum wavelength data through the strain analysis branch of the dual-task analysis network to obtain a strain wavelength offset, and performing dynamic trajectory tracking based on the light spot position data through the temperature compensation branch of the dual-task analysis network to obtain a temperature wavelength correction; Based on the independent spectral data, combined with the time series data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, dynamically adjust the shared layer weights of the dual-task analysis network to generate a temperature-decoupled strain demodulation value; Based on the temperature-decoupled strain demodulation value, a standardized strain characteristic signal is generated through photoelectric signal conversion, and the characteristic signal is transmitted to the monitoring system to reconstruct the dynamic distribution diagram of the axial strain of the multi-core optical fiber and synchronously display the temperature compensation status curve.

2. The method according to claim 1, characterized in that Constructing a parallel dual-task analysis network, performing continuous waveform comparison based on the minimum wavelength data through the strain analysis branch of the dual-task analysis network to obtain a strain wavelength offset, and performing dynamic trajectory tracking based on the light spot position data through the temperature compensation branch of the dual-task analysis network to obtain a temperature wavelength correction, including: Building a dual-task analysis network with parallel processing paths, the network includes two parallel processing branches: a strain analysis branch and a temperature compensation branch, and the two branches share some initial processing units; Extracting the waveform feature corresponding to the lowest wavelength data through the strain analysis branch, continuously comparing the waveform feature at the current moment with the waveform feature at the previous moment, recording the difference between the two waveforms, and obtaining the strain wavelength offset; The temperature compensation branch is used to track the position change trajectory of the light spot at different times, continuously record the position points on the position change trajectory, analyze the movement amplitude and direction of the position points, and obtain the temperature wavelength correction amount.

3. The method according to claim 2, characterized in that Extracting the waveform feature corresponding to the lowest wavelength data through the strain analysis branch, continuously comparing the waveform feature at the current moment with the waveform feature at the previous moment, recording the difference between the two waveforms, and obtaining the strain wavelength offset, including: Dividing the minimum wavelength data into data segments according to preset time intervals, each data segment corresponds to the minimum wavelength data at a moment, and sequentially inputting the minimum wavelength data at each moment into the strain analysis branch; Based on the input minimum wavelength data, the strain analysis branch identifies the vertex position, inflection point position and fluctuation range in the waveform corresponding to the data at each moment as the waveform features at each moment; Calculating the difference between the corresponding vertex positions and the inflection point positions based on the waveform characteristics at the current moment and the waveform characteristics at the previous moment, and performing an overlapping comparison on the fluctuation ranges at the current moment and the previous moment to determine the change in the fluctuation range boundary; The difference in the vertex position, the difference in the inflection point position and the change in the fluctuation range boundary are comprehensively calculated, and the difference between the two waveforms is recorded to obtain the strain wavelength offset.

4. The method according to claim 2, characterized in that Tracking the position change trajectory of the light spot at different times through the temperature compensation branch, continuously recording the position points on the position change trajectory, analyzing the movement amplitude and direction of the position points, and obtaining the temperature wavelength correction value, including: collecting light spot position data at different times according to preset time intervals, and inputting the light spot position data into the temperature compensation branch in sequence; Identify the spatial position of the light spot at each moment through the temperature compensation branch, mark it as a position point, and connect the position points at different moments in time sequence to form a position change trajectory of the light spot; Selecting position points at adjacent moments in the position change trajectory, calculating the straight-line distance between the position points at the adjacent moments as the movement amplitude, and determining the spatial offset direction of the position point at the latter moment relative to the position point at the previous moment as the movement direction; The movement amplitude and the movement direction in a plurality of consecutive time periods are recorded, and the movement amplitude and the offset corresponding to the movement direction are correlated and calculated to obtain a temperature wavelength correction amount.

5. The method according to claim 1, wherein Based on the independent spectral data, combined with the time series data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, the shared layer weights of the dual-task analysis network are dynamically adjusted to generate a temperature-decoupled strain demodulation value, including: Acquiring the generated independent spectrum data, collecting time series data of the strain wavelength offset changing over time, and amplitude fluctuation data of the temperature wavelength correction amount; The independent spectrum data, time series data and amplitude fluctuation data are simultaneously input into the shared layer of the dual-task analysis network, and the optical signal characteristics of the fiber cores on both sides in the independent spectrum data are analyzed by the shared layer; Based on the optical signal characteristics, combined with the changing 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 strength of each processing unit in the shared layer is dynamically adjusted; By increasing the shared layer weight of the strain-related signal features in the optical signal features and decreasing the shared layer weight of the temperature-related signal features, an adjusted dual-task analysis network is obtained; The input data is processed by the adjusted dual-task analysis network to generate strain demodulation values ​​that eliminate the temperature influence, that is, temperature-decoupled strain demodulation values.

6. The method according to claim 1, characterized in that The composite light output by the multi-core optical fiber is split twice using a diffraction grating, and the spectrum of the two cores is projected onto non-overlapping areas of the photoelectric array to generate independent spectrum data. Based on the independent spectrum data, the coupling between the two cores is blocked by an air layer to enhance the strain sensitivity, including: Inputting the composite light output from the multi-core optical fiber into a diffraction grating, performing a first splitting on the diffraction grating to obtain preliminary separated signals of different wavelengths, and then performing a second splitting on the preliminary separated signals by the diffraction grating to obtain optical signals of different wavelengths with an expanded degree of separation; A photoelectric array is provided at the optical signal emission port of the diffraction grating, the photoelectric array is divided into two independent areas that do not overlap, and the optical signal after the secondary splitting is projected into the two independent areas respectively; Based on the projection of the optical signal within the corresponding photoelectric array area, respective spectral images are formed, and the photoelectric array converts the spectral images into electrical signals to generate independent spectral data for the fiber cores on both sides. The independent spectral data reflects the changes in the optical signals of the fiber cores on both sides affected by the strain; An air layer is provided between the two cores of the multi-core optical fiber, and the air layer prevents the optical signals between the two cores from coupling with each other, thereby enhancing the strain sensitivity.

7. The method according to claim 1, characterized in that 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 the monitoring system, the dynamic distribution diagram of the axial strain of the multi-core optical fiber is reconstructed, and the temperature compensation status curve is simultaneously displayed, including: Inputting the temperature-decoupled strain demodulation value into a photoelectric conversion device, and converting the optical signal corresponding to the strain demodulation value into an electrical signal through the photoelectric conversion device; Standardizing the converted electrical signal so that the amplitude and range of the signal are within a preset standard range, thereby generating a standardized strain characteristic signal; The strain characteristic signal is sent to a monitoring system via a data transmission line. After receiving the signal, the monitoring system arranges the strain characteristic signals corresponding to different positions axially 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; The temperature wavelength correction data is extracted through the monitoring system, and the change of the temperature wavelength correction data over time is presented in the form of a curve, and is synchronously displayed on the monitoring interface with the dynamic distribution diagram.

8. A multi-core optical fiber strain and temperature decoupling system with grating demodulation, characterized in that: include: An acquisition module is used to obtain the lowest wavelength data of the 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 secondary dispersion of the diffraction grating; A blocking module is used to perform secondary splitting of the composite light output by the multi-core optical fiber using a diffraction grating, project the spectrum of the two cores on each side into non-overlapping areas of the photoelectric array, generate independent spectral data, and block the coupling of the two core light paths through the air layer based on the independent spectral data to enhance the strain sensitivity; a construction module for constructing a parallel dual-task analysis network, performing continuous waveform comparison based on the minimum wavelength data through the strain analysis branch of the dual-task analysis network to obtain a strain wavelength offset, and performing dynamic trajectory tracking based on the light spot position data through the temperature compensation branch of the dual-task analysis network to obtain a temperature wavelength correction; an adjustment module for dynamically adjusting the shared layer weights of the dual-task analysis network based on the independent spectral data, in combination with the time series data of the strain wavelength offset and the amplitude fluctuation of the temperature wavelength correction, to generate a temperature-decoupled strain demodulation value; A reconstruction module is used to generate a standardized strain characteristic signal through photoelectric signal conversion based on the strain demodulation value of the temperature decoupling, transmit the characteristic signal to the monitoring system, reconstruct the dynamic distribution diagram of the axial strain of the multi-core optical fiber, and synchronously display the temperature compensation status curve.

9. An electronic device, characterized in that: include: memory for storing computer programs; A processor, configured to implement the steps of the multi-core optical fiber strain and temperature decoupling method for grating demodulation according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the multi-core optical fiber strain and temperature decoupling method for grating demodulation according to any one of claims 1 to 7 can be implemented.

Images