Distributed optical fiber data processing method with multi-dimensional deformation monitoring capability

Abstract

A distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring belongs to the technical field of data analysis and identification. The data processing method comprises the following steps: using multiple control points and mileage data to establish a control network, and converting two-dimensional information into three-dimensional information; using stress and strain monitoring data to calculate the three-dimensional deformation data in the independent coordinate system of the distributed optical fiber; calculating and solving the three-dimensional deformation data based on multiple common point information and multiple parameter information; judging and extracting the strain monitoring data of the distributed optical fiber, removing the noise signal in the original data, and obtaining accurate and reliable deformation monitoring information data, thereby realizing real-time monitoring and advance warning of deformation phenomena.

Description

Technical Field

[0001] The invention relates to a distributed optical fiber data processing method capable of identifying multi-dimensional deformation monitoring. Background Art

[0002] With the development of technology and the progress of society, urban construction has gradually formed a layout of multi-space distribution underground and above ground. Among them, the increasing number of underground projects such as underground pipelines and tunnels has led to the continuous emergence of high-rise and super-high-rise underground buildings; the construction of above-ground and underground projects will inevitably induce deformation of strata and buildings. When the degree of deformation exceeds the threshold range, secondary geological disasters such as settlement, collapse, landslide, and mudslide are very likely to occur, seriously threatening people’s lives and property safety; therefore, it is extremely important to carry out real-time dynamic deformation monitoring of above-ground and underground space construction.

[0003] There are various forms of existing deformation monitoring, which can be divided into visible monitoring and penetrating monitoring according to different measurement methods; among them, visible monitoring mainly includes leveling, measuring robots, optical remote sensing image recognition, etc. Visible monitoring has dynamic and large-scale monitoring capabilities, but cannot realize internal deformation monitoring of structures; penetrating monitoring mainly includes microwave remote sensing monitoring, sensor monitoring, etc., which can identify deformation information at different locations according to different installation positions and have certain penetrating monitoring capabilities, but the sensors are distributed in a point-like manner and cannot realize the overall deformation state of the hidden space. There is a lack of real-time monitoring means for hidden spaces, and it is impossible to perform high-precision deformation monitoring around the clock, and thus it is impossible to monitor the deformation information of hidden spaces in real time and provide advance warning. Summary of the invention

[0004] The embodiment of the present invention provides a distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring. The method is reasonably designed, based on the advantages and characteristics of distributed optical fiber, installed inside the building structure, and combined with multiple types of algorithms and data interactions. It can identify the two-dimensional tensile deformation of objects in hidden places, realize real-time dynamic deformation monitoring and high-precision all-round stress change monitoring of hidden spaces, and then conduct real-time monitoring and advance warning of deformation, damage, deterioration, collapse and other phenomena caused by ground space projects and underground space projects, thereby ensuring the stability and safety of ground space projects and underground space projects, and solving the problems existing in the prior art.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A distributed optical fiber data processing method having the ability to identify multi-dimensional deformation monitoring, the data processing method comprising the following steps:

[0007] S1, using multiple control points and mileage data to establish a control network and convert two-dimensional information into three-dimensional information;

[0008] S2, using stress and strain monitoring data to calculate the three-dimensional deformation data of the distributed optical fiber in an independent coordinate system;

[0009] S3, calculating and solving the three-dimensional deformation data according to the multiple common point information and the multiple parameter information;

[0010] S4, judges and extracts the strain monitoring data of the distributed optical fiber, removes the noise signal in the original data, and obtains accurate and reliable deformation monitoring information data, thereby realizing real-time monitoring and advance warning of deformation phenomena.

[0011] The distributed optical fiber includes a strain sensing single-mode optical fiber, and a strain transmission layer, a rubber material optical fiber protection layer, a buffer and a strain transmission layer and a buffer layer are sequentially arranged outside the strain sensing single-mode optical fiber;

[0012] The elastic modulus, Poisson's ratio and compressive strength of the rubber material optical fiber protective layer are similar to those of the object to be measured, and can achieve coordinated deformation with the object to be measured;

[0013] The material with the buffer and strain transmission layer has a high elastic modulus, can quickly recover to its original shape after being subjected to force, can remain stable under complex stress conditions, absorbs energy when stretched or compressed, and is not easily broken or deformed.

[0014] Using multiple control points and mileage data to establish a control network, converting two-dimensional information into three-dimensional information includes the following steps:

[0015] S1.1, selecting 3-4 control points of known locations in the distributed optical fiber deployment area, wherein the control points include physical landmarks and identifiable marking points;

[0016] S1.2, construct an independent optical fiber coordinate system with the X axis parallel to the optical fiber laying direction, the Y axis perpendicular to the optical fiber laying direction, and the Z axis in the mileage direction;

[0017] S1.3, record the mileage data of the optical fiber, monitor the coordinates of the turning points of the optical fiber layout line, use the interpolation method to obtain the coordinate values ​​of the monitoring points of the optical fiber line, and establish the initial three-dimensional shape of the optical fiber;

[0018] S1.4, strain calculation along the X-axis direction of the optical fiber: select the optical fiber measuring the X-axis direction in the multi-core optical fiber as the X-axis direction for data processing, and calculate the change of the optical fiber projection on the XOZ plane based on the strain difference of the optical fiber data; strain calculation along the Y-axis direction of the optical fiber: select the optical fiber measuring the Y-axis direction in the multi-core optical fiber as the Y-axis direction for data processing, and calculate the change of the optical fiber projection on the YOZ plane based on the strain difference of the optical fiber data;

[0019] S1.5, calculating the three-dimensional deformation information of the optical fiber according to the optical fiber projection deformation information on two mutually perpendicular planes XOZ and YOZ;

[0020] S1.6, denoising the optical fiber data;

[0021] S1.7, measure the control point data, combine the conversion parameters between the fiber independent coordinate system and the engineering coordinate system, and convert the monitoring data into three-dimensional deformation information under the engineering coordinate system.

[0022] Using stress-strain monitoring data to calculate the three-dimensional deformation data in the distributed optical fiber coordinate system includes the following steps:

[0023] S2.1, using a three-dimensional curve to represent the optical fiber deformation curve, and decomposing the three-dimensional curve into an optical fiber horizontal deformation information curve and an optical fiber vertical deformation information curve;

[0024] S2.2, decompose the optical fiber horizontal deformation information curve into multiple arcs, recorded as P1, P2…P n ;

[0025] S2.3, perform equivalent calculation on the horizontal deformation segments, for any segmented arc P i , under the premise that the relative position of the optical fiber remains unchanged, any segmented arc P can be obtained i The radius of curvature and the angles of rotation of the two cross sections on the segmented arc around their respective neutral axes, that is:

[0026] ;

[0027] Among them, the positive sign represents tension and the negative sign represents compression;

[0028] S2.4, interpolate the deformation information of different arc segments of the horizontal deformation curve, divide the optical fiber horizontal deformation information curve into several segments, take the nth segment for observation, and set P n and P n+1 are the two endpoints of the nth segment, and the corresponding chord length is l n , O n is the center of the circle corresponding to this segment, and the radius of curvature is R n , P n The angle between the tangent line of the point and the X-axis is θ n , P n+1 The angle between the tangent line of the point and the X-axis is θ n+1 ; Set P n and P n+1 The coordinates of n ,y n ) and (x n+1 ,y n+1 ), the corresponding curvatures are P n , Pn+1 ; According to the strain information measured by the distributed sensor, the curvature of each end point is calculated according to the above parameters, and then the deformation information curve of the optical fiber in the horizontal direction is drawn;

[0029] S2.5, draw the optical fiber vertical deformation information curve according to the above steps, fit the optical fiber morphology using the optical fiber horizontal deformation information, the optical fiber vertical deformation information curve and the optical fiber mileage, and verify the deformation information based on the optical fiber independent coordinate system.

[0030] The calculation and solution of three-dimensional deformation data based on multiple common point information and multiple parameter information includes the following steps:

[0031] S3.1, select at least 4 optical fiber feature points and use a measuring device to measure the three-dimensional coordinates of the control points;

[0032] S3.2, using three common point information and a seven-parameter calculation formula to solve the seven-parameter information for converting the optical fiber independent coordinate system to the engineering coordinate system; the seven-parameter information includes a scale factor, an X-direction translation parameter, a Y-direction translation parameter, a Z-direction translation parameter, a rotation angle around the X-axis, a rotation angle around the Y-axis, and a rotation angle around the Z-axis;

[0033] S3.3, transform the solved seven parameter information in all optical fiber independent coordinate systems to obtain three-dimensional coordinates in the engineering coordinate system.

[0034] For the three common points, a fourth common point can also be set as a verification point.

[0035] Judging and extracting the strain monitoring data of distributed optical fibers, removing noise signals from the original data, and obtaining accurate and reliable deformation monitoring information data include the following steps:

[0036] S4.1, using wavelet analysis algorithm to perform noise removal operation on deformation monitoring information data;

[0037] S4.2, the denoised deformation monitoring information data is smoothed and trimmed using the moving mean algorithm, Savitzky-Goiay algorithm and percentile filtering algorithm.

[0038] The use of wavelet analysis algorithm to remove noise from deformation monitoring information data includes the following steps:

[0039] S4.1.1, the collected original deformation monitoring information data is divided into two layers by wavelet function;

[0040] S4.1.2, using different threshold processing methods to process high-frequency signals at each level;

[0041] S4.1.3, using wavelet reconstruction transform to eliminate noise signals; the wavelet reconstruction transform contains two variables, namely scale parameter a and translation parameter b, scale parameter a corresponds to frequency, and translation parameter b corresponds to time, so wavelet transform can be used for time-frequency analysis to obtain the time-frequency spectrum of the signal; scaling and translating the wavelet function can obtain a wavelet sequence:

[0042] ;

[0043] S4.1.4, according to the characteristics and applicability of soft and hard thresholds, select the soft threshold to process the high-frequency signals of each level, reconstruct the processed signals and low-frequency signals, and obtain the denoised signals.

[0044] The smoothing and trimming of the denoised deformation monitoring information data using the moving mean algorithm, Savitzky-Goiay algorithm and percentile filtering algorithm includes the following steps:

[0045] S4.2.1, set a set of data in a window as x[i], i=[-m,m], i takes 2m+1 consecutive integer values, and construct an n-order polynomial to fit this set of data, n≤2m+1;

[0046] S4.2.2, solve the residual sum of squares between the fitted data points and the original data points to ensure the stability and accuracy of the deformation monitoring information data.

[0047] The data processing system corresponding to the data processing method includes:

[0048] A conversion module, the conversion module is used to establish a control network using multiple control points and mileage data, and convert two-dimensional information into three-dimensional information;

[0049] A summary module, the summary module is used to calculate the three-dimensional deformation data of the distributed optical fiber in an independent coordinate system using the stress and strain monitoring data;

[0050] A calculation module, the calculation module is used to calculate and solve the three-dimensional deformation data according to multiple common point information and multiple parameter information;

[0051] The analysis module is used to judge and extract the strain monitoring data of the distributed optical fiber, remove the noise signal in the original data, and obtain accurate and reliable deformation monitoring information data, thereby realizing real-time monitoring and advance warning of deformation phenomena.

[0052] The present invention adopts the above method, establishes a control network by using multiple control points and mileage data, and converts two-dimensional information into three-dimensional information; calculates the three-dimensional deformation data in the independent coordinate system of the distributed optical fiber by using stress and strain monitoring data; calculates and solves the three-dimensional deformation data according to three common point information and seven parameter information; judges and extracts the strain monitoring data of the distributed optical fiber, removes the noise signal in the original data, and obtains accurate and reliable deformation monitoring information data, thereby realizing real-time monitoring and advance warning of deformation phenomena, which has the advantages of safety, reliability, accuracy and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a schematic diagram of the process of the present invention.

[0054] Figure 2 It is a graph of the three-dimensional deformation information of the optical fiber of the present invention.

[0055] Figure 3 It is a graph of the two-dimensional deformation information of the optical fiber of the present invention.

[0056] Figure 4 It is a schematic diagram of deformation information interpolation calculation of the present invention. DETAILED DESCRIPTION

[0057] In order to clearly illustrate the technical features of the present solution, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0058] like Figure 1-Figure 4 As shown in , a distributed optical fiber data processing method having the ability to identify multi-dimensional deformation monitoring, the data processing method comprises the following steps:

[0059] S1, using multiple control points and mileage data to establish a control network and convert two-dimensional information into three-dimensional information;

[0060] S2, using stress and strain monitoring data to calculate the three-dimensional deformation data of the distributed optical fiber in an independent coordinate system;

[0061] S3, calculating and solving the three-dimensional deformation data according to the multiple common point information and the multiple parameter information;

[0062] S4, judges and extracts the strain monitoring data of the distributed optical fiber, removes the noise signal in the original data, and obtains accurate and reliable deformation monitoring information data, thereby realizing real-time monitoring and advance warning of deformation phenomena.

[0063] The distributed optical fiber includes a strain sensing single-mode optical fiber, and a strain transmission layer, a rubber material optical fiber protection layer, a buffer and a strain transmission layer and a buffer layer are sequentially arranged outside the strain sensing single-mode optical fiber;

[0064] The elastic modulus, Poisson's ratio and compressive strength of the rubber material optical fiber protective layer are similar to those of the object to be measured, and can achieve coordinated deformation with the object to be measured;

[0065] The material with the buffer and strain transmission layer has a high elastic modulus, can quickly recover to its original shape after being subjected to force, can remain stable under complex stress conditions, absorbs energy when stretched or compressed, and is not easily broken or deformed.

[0066] Using multiple control points and mileage data to establish a control network, converting two-dimensional information into three-dimensional information includes the following steps:

[0067] S1.1, selecting 3-4 control points of known locations in the distributed optical fiber deployment area, wherein the control points include physical landmarks and identifiable marking points;

[0068] S1.2, construct an independent optical fiber coordinate system with the X axis parallel to the optical fiber laying direction, the Y axis perpendicular to the optical fiber laying direction, and the Z axis in the mileage direction;

[0069] S1.3, record the mileage data of the optical fiber, monitor the coordinates of the turning points of the optical fiber layout line, use the interpolation method to obtain the coordinate values ​​of the monitoring points of the optical fiber line, and establish the initial three-dimensional shape of the optical fiber;

[0070] S1.4, strain calculation along the X-axis direction of the optical fiber: select the optical fiber measuring the X-axis direction in the multi-core optical fiber as the X-axis direction for data processing, and calculate the change of the optical fiber projection on the XOZ plane based on the strain difference of the optical fiber data; strain calculation along the Y-axis direction of the optical fiber: select the optical fiber measuring the Y-axis direction in the multi-core optical fiber as the Y-axis direction for data processing, and calculate the change of the optical fiber projection on the YOZ plane based on the strain difference of the optical fiber data;

[0071] S1.5, calculating the three-dimensional deformation information of the optical fiber according to the optical fiber projection deformation information on two mutually perpendicular planes XOZ and YOZ;

[0072] S1.6, denoising the optical fiber data;

[0073] S1.7, measure the control point data, combine the conversion parameters between the fiber independent coordinate system and the engineering coordinate system, and convert the monitoring data into three-dimensional deformation information under the engineering coordinate system.

[0074] Using stress-strain monitoring data to calculate the three-dimensional deformation data in the distributed optical fiber coordinate system includes the following steps:

[0075] S2.1, using a three-dimensional curve to represent the optical fiber deformation curve, and decomposing the three-dimensional curve into an optical fiber horizontal deformation information curve and an optical fiber vertical deformation information curve;

[0076] S2.2, decompose the optical fiber horizontal deformation information curve into multiple arcs, recorded as P1, P2…P n ;

[0077] S2.3, perform equivalent calculation on the horizontal deformation segments, for any segmented arc P i , under the premise that the relative position of the optical fiber remains unchanged, any segmented arc P can be obtained i The radius of curvature and the angles of rotation of the two cross sections on the segmented arc around their respective neutral axes, that is:

[0078] ;

[0079] Among them, the positive sign represents tension and the negative sign represents compression;

[0080] S2.4, interpolate the deformation information of different arc segments of the horizontal deformation curve, divide the optical fiber horizontal deformation information curve into several segments, take the nth segment for observation, and set P n and P n+1 are the two endpoints of the nth segment, and the corresponding chord length is l n , O n is the center of the circle corresponding to this segment, and the radius of curvature is R n , P n The angle between the tangent line of the point and the X-axis is θ n , P n+1 The angle between the tangent line of the point and the X-axis is θ n+1 ; Set P n and P n+1 The coordinates of n ,y n ) and (x n+1 ,y n+1 ), the corresponding curvatures are P n , P n+1 ; According to the strain information measured by the distributed sensor, the curvature of each end point is calculated according to the above parameters, and then the deformation information curve of the optical fiber in the horizontal direction is drawn;

[0081] S2.5, draw the optical fiber vertical deformation information curve according to the above steps, fit the optical fiber morphology using the optical fiber horizontal deformation information, the optical fiber vertical deformation information curve and the optical fiber mileage, and verify the deformation information based on the optical fiber independent coordinate system.

[0082] The calculation and solution of three-dimensional deformation data based on multiple common point information and multiple parameter information includes the following steps:

[0083] S3.1, select at least 4 optical fiber feature points and use a measuring device to measure the three-dimensional coordinates of the control points;

[0084] S3.2, using three common point information and a seven-parameter calculation formula to solve the seven-parameter information for converting the optical fiber independent coordinate system to the engineering coordinate system; the seven-parameter information includes a scale factor, an X-direction translation parameter, a Y-direction translation parameter, a Z-direction translation parameter, a rotation angle around the X-axis, a rotation angle around the Y-axis, and a rotation angle around the Z-axis;

[0085] S3.3, transform the solved seven parameter information in all optical fiber independent coordinate systems to obtain three-dimensional coordinates in the engineering coordinate system.

[0086] For the three common points, a fourth common point can also be set as a verification point.

[0087] Judging and extracting the strain monitoring data of distributed optical fibers, removing noise signals from the original data, and obtaining accurate and reliable deformation monitoring information data include the following steps:

[0088] S4.1, using wavelet analysis algorithm to perform noise removal operation on deformation monitoring information data;

[0089] S4.2, the denoised deformation monitoring information data is smoothed and trimmed using the moving mean algorithm, Savitzky-Goiay algorithm and percentile filtering algorithm.

[0090] The use of wavelet analysis algorithm to remove noise from deformation monitoring information data includes the following steps:

[0091] S4.1.1, the collected original deformation monitoring information data is divided into two layers by wavelet function;

[0092] S4.1.2, using different threshold processing methods to process high-frequency signals at each level;

[0093] S4.1.3, using wavelet reconstruction transform to eliminate noise signals; the wavelet reconstruction transform contains two variables, namely scale parameter a and translation parameter b, scale parameter a corresponds to frequency, and translation parameter b corresponds to time, so wavelet transform can be used for time-frequency analysis to obtain the time-frequency spectrum of the signal; scaling and translating the wavelet function can obtain a wavelet sequence:

[0094] ;

[0095] S4.1.4, according to the characteristics and applicability of soft and hard thresholds, select the soft threshold to process the high-frequency signals of each level, reconstruct the processed signals and low-frequency signals, and obtain the denoised signals.

[0096] The smoothing and trimming of the denoised deformation monitoring information data using the moving mean algorithm, Savitzky-Goiay algorithm and percentile filtering algorithm includes the following steps:

[0097] S4.2.1, set a set of data in a window as x[i], i=[-m,m], i takes 2m+1 consecutive integer values, and construct an n-order polynomial to fit this set of data, n≤2m+1;

[0098] S4.2.2, solve the residual sum of squares between the fitted data points and the original data points to ensure the stability and accuracy of the deformation monitoring information data.

[0099] The data processing system corresponding to the data processing method includes:

[0100] A conversion module, the conversion module is used to establish a control network using multiple control points and mileage data, and convert two-dimensional information into three-dimensional information;

[0101] A summary module, the summary module is used to calculate the three-dimensional deformation data of the distributed optical fiber in an independent coordinate system using the stress and strain monitoring data;

[0102] A calculation module, the calculation module is used to calculate and solve the three-dimensional deformation data according to multiple common point information and multiple parameter information;

[0103] The analysis module is used to judge and extract the strain monitoring data of the distributed optical fiber, remove the noise signal in the original data, and obtain accurate and reliable deformation monitoring information data, thereby realizing real-time monitoring and advance warning of deformation phenomena.

[0104] The working principle of the distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring in the embodiment of the present invention is: based on the advantages and characteristics of distributed optical fiber, it is installed inside the building structure, combined with multiple types of algorithms and data interaction, it can identify the two-dimensional tensile deformation of objects in hidden places, and realize real-time dynamic deformation monitoring and high-precision all-round stress change monitoring of hidden spaces, and then carry out real-time monitoring and advance warning of deformation, damage, deterioration, collapse and other phenomena caused by ground space projects and underground space projects, thereby ensuring the stability and safety of ground space projects and underground space projects.

[0105] Fully distributed fiber optic monitoring has the advantages of strong anti-interference, micron-level high precision, high metering rate, and real-time dynamic monitoring. However, the lack of multi-dimensional directional deformation monitoring capability of fully distributed optical fiber has seriously restricted the promotion and application of this technology, resulting in limited application of fully distributed optical fiber, especially in the deformation monitoring of concealed spaces such as underground and building structures. Therefore, the application can be combined with corresponding algorithms to give full play to the functional role of distributed optical fiber, and can perform real-time monitoring of concealed spaces of ground space projects and underground space projects with high precision around the clock.

[0106] In the overall solution, the data processing method includes the following steps: using multiple control points and mileage data to establish a control network to convert two-dimensional information into three-dimensional information; using stress and strain monitoring data to calculate the three-dimensional deformation data in the independent coordinate system of the distributed optical fiber; calculating and solving the three-dimensional deformation data based on multiple common point information and multiple parameter information; judging and extracting the strain monitoring data of the distributed optical fiber, removing the noise signal in the original data, and obtaining accurate and reliable deformation monitoring information data, thereby realizing real-time monitoring and advance warning of deformation phenomena.

[0107] The distributed optical fiber of the present application includes a strain sensing single-mode optical fiber, on the outside of which a strain transmission layer, a rubber material optical fiber protective layer, a buffer and strain transmission layer and a buffer layer are sequentially arranged; thereby achieving high-precision and all-round monitoring of stress and strain changes in concealed spaces, solving the problem that previous fixed-point sensors could not conduct comprehensive monitoring.

[0108] The elastic modulus, Poisson's ratio and compressive strength of the rubber material optical fiber protective layer are similar to those of the object to be measured, and can achieve coordinated deformation with the object to be measured; the material with a buffer and strain transmission layer has a high elastic modulus, can quickly recover to its original state after being subjected to force, can remain stable under complex stress conditions, absorb energy when stretched or compressed, and is not easy to break or deform.

[0109] Furthermore, distributed optical fiber also has high ductility and can undergo reversible deformation when subjected to force, rather than plastic deformation or fracture; good temperature stability and can remain relatively stable at different temperatures; good thermal insulation and can effectively maintain temperature differences, prevent heat from escaping or entering, and reduce the impact of temperature on deformation monitoring accuracy.

[0110] In actual use, preferably, a control network is established using multiple control points and mileage data, and the conversion of two-dimensional information into three-dimensional information includes the following steps: select 3-4 control points of known positions in the distributed optical fiber layout area, wherein the control points include physical landmarks and identifiable marking points; construct an independent optical fiber coordinate system with the X-axis parallel to the optical fiber layout direction, the Y-axis perpendicular to the optical fiber layout direction, and the Z-axis perpendicular to the optical fiber layout direction; record the mileage data of the optical fiber, monitor the inflection point coordinates of the optical fiber layout line, use the interpolation method to obtain the coordinate values ​​of the monitoring points of the optical fiber line, and establish the initial three-dimensional shape of the optical fiber; perform strain calculation along the X-axis direction of the optical fiber: select the X-axis measured in the multi-core optical fiber The optical fiber in the Y-axis direction is selected as the X-axis direction for data processing, and the change of the optical fiber projection on the XOZ plane is calculated according to the strain difference of the optical fiber data; the strain calculation is performed along the Y-axis direction of the optical fiber: the optical fiber measuring the Y-axis direction in the multi-core optical fiber is selected as the Y-axis direction for data processing, and the change of the optical fiber projection on the YOZ plane is calculated according to the strain difference of the optical fiber data; the three-dimensional deformation information of the optical fiber is calculated according to the deformation information of the optical fiber projection on the two mutually perpendicular planes of XOZ and YOZ; the optical fiber data is denoised; the control point data is measured, and the monitoring data is converted into three-dimensional deformation information under the engineering coordinate system in combination with the conversion parameters of the optical fiber independent coordinate system and the engineering coordinate system.

[0111] Generally speaking, the shape of an optical fiber after deformation with the object being measured is a three-dimensional curve. Limited by the limitations of optical fiber materials, the deformation of the optical fiber is mainly curve deformation. Two points close enough on the curve of optical fiber deformation can be regarded as micro-arcs. In a plane, for any micro-arc, under the premise of certain curvature radius, center angle, and starting coordinates, the coordinates of the end point of the micro-arc can be solved.

[0112] In detail, using stress-strain monitoring data to calculate the three-dimensional deformation data in the distributed optical fiber coordinate system includes the following steps: using a three-dimensional curve to represent the optical fiber deformation curve, decomposing the three-dimensional curve into an optical fiber horizontal deformation information curve and an optical fiber vertical deformation information curve; decomposing the optical fiber horizontal deformation information curve into multiple arcs, recorded as P1, P2…P n ; Perform equivalent calculation on the horizontal deformation segments, for any segmented arc P i , under the premise that the relative position of the optical fiber remains unchanged, any segmented arc P can be obtained i The radius of curvature and the angles of rotation of the two cross sections on the segmented arc around their respective neutral axes, that is:

[0113] ;

[0114] Among them, the positive sign represents tension and the negative sign represents compression;

[0115] Interpolate the deformation information of different arc segments of the horizontal deformation curve, divide the optical fiber horizontal deformation information curve into several segments, take the nth segment for observation, and set P n and P n+1 are the two endpoints of the nth segment, and the corresponding chord length is l n , O n is the center of the circle corresponding to this segment, and the radius of curvature is R n , P n The angle between the tangent line of the point and the X-axis is θ n , P n+1 The angle between the tangent line of the point and the X-axis is θ n+1 ; Set P n and P n+1 The coordinates of n ,y n ) and (x n+1 ,y n+1 ), the corresponding curvatures are P n , P n+1 ; According to the strain information measured by the distributed sensor, the curvature of each endpoint is calculated according to the above parameters, and then the horizontal deformation information curve of the optical fiber is drawn; referring to the above steps to draw the vertical deformation information curve of the optical fiber, the horizontal deformation information of the optical fiber, the vertical deformation information curve of the optical fiber and the optical fiber mileage are used to fit the optical fiber morphology, and the deformation information is verified based on the independent coordinate system of the optical fiber.

[0116] Since each small segment is regarded as an arc and the curvature of the left endpoint of each small segment is used to replace the curvature of the entire segment, there is a certain approximate substitution error, which causes a cumulative effect of the error. As the reconstruction points continue to advance, the error will gradually increase. Therefore, in order to improve the reconstruction accuracy, the interpolation method is used to perform linear interpolation on the deformation information.

[0117] Furthermore, the fiber deformation can be obtained by measuring the fiber at the center, and can also be calculated from the arc length parameters and endpoint coordinates of the three-dimensional curve obtained by morphological fitting. Therefore, the accuracy of fiber morphological restoration in different sections is checked and evaluated. When the fiber accuracy is poor, the micro-arc should be further refined and decomposed, and the data calculation of the whole process should be repeated.

[0118] An innovation of the present application is to calculate and solve the three-dimensional deformation data based on multiple common point information and multiple parameter information; specifically, the following steps are included: selecting at least 4 optical fiber feature points, and using a measuring device to measure the three-dimensional coordinates of the control points; using 3 common point information and a seven-parameter calculation formula to solve the seven-parameter information for converting the optical fiber independent coordinate system to the engineering coordinate system; the seven-parameter information includes a scale factor, an X-direction translation parameter, a Y-direction translation parameter, a Z-direction translation parameter, a rotation angle around the X-axis, a rotation angle around the Y-axis, and a rotation angle around the Z-axis; the solved seven-parameter information is subjected to coordinate transformation in all optical fiber independent coordinate systems to obtain the three-dimensional coordinates in the engineering coordinate system.

[0119] The optical fiber independent coordinate system and the engineering coordinate system are combined and converted, and the three-dimensional coordinates of the control points are measured using GPS, total station and other measuring equipment. The fourth common point is used as the verification point to obtain accurate and reliable universal three-dimensional coordinates.

[0120] Since there are a lot of noise signals in the original data, it is necessary to perform certain denoising and smoothing processing on the original data.

[0121] Specifically, the strain monitoring data of the distributed optical fiber is judged and extracted, the noise signal in the original data is removed, and the accurate and reliable deformation monitoring information data is obtained, which includes the following steps: using a wavelet analysis algorithm to denoise the deformation monitoring information data; using a shifting mean algorithm, a Savitzky-Goiay algorithm and a percentile filtering algorithm to smooth and trim the denoised deformation monitoring information data.

[0122] Furthermore, the wavelet analysis algorithm is used to perform denoising operation on deformation monitoring information data, including the following steps: the collected original deformation monitoring information data is divided into two layers by wavelet function; different threshold processing methods are used to process high-frequency signals at each level; and the noise signal is eliminated by wavelet reconstruction transform; the wavelet reconstruction transform contains two variables, namely, scale parameter a and translation parameter b, scale parameter a corresponds to frequency, and translation parameter b corresponds to time, so wavelet transform can be used for time-frequency analysis to obtain the time-frequency spectrum of the signal; scaling and translating the wavelet function can obtain a wavelet sequence:

[0123] ;

[0124] The unbiased risk threshold rigid processing method based on Stein is adopted. According to the characteristics and applicability of soft and hard thresholds, the soft threshold is selected to process the high-frequency signals of each level, and the processed signals and low-frequency signals are reconstructed to obtain the denoised signals:

[0125] ;

[0126] in, .

[0127] In the process of data smoothing and trimming, due to the large amount of field monitoring data, the trend of the smoothed curve should be consistent with the original signal; the number of items in the shifting mean method is the average value of the corresponding values ​​of every 40 points before and after the midpoint data is obtained; and the Savitzky-Goiay method is a polynomial curve fitting method, which is also a commonly used data fitting method, and its formula coefficient is generally quadratic.

[0128] Specifically, firstly, a set of data in a window is set to x[i], i=[-m,m], the value of i is 2m+1 consecutive integer values, and an n-order polynomial is constructed to fit this set of data, n≤2m+1; the residual sum of squares between the fitting data points and the original data points is solved to ensure the smoothness and accuracy of the deformation monitoring information data.

[0129] The distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring in the embodiment of the present invention has been field tested and successfully applied to subway construction projects, showing feasibility; it can capture disaster signs based on the real-time change characteristics of the monitoring data, ensuring the safety of subway construction and ground driving; in addition, the efficiency of deformation monitoring during subway construction is also improved.

[0130] Specifically, the settlement values ​​of the urban road network in the area to be inspected, the distribution status of cracks in the urban road network, and the real-time change values ​​of the road curvature are obtained, and an assessment and early warning model for construction and road risks is constructed. Numerical simulation calculations are performed based on the model, risk points and risk areas are delineated, and early warning control areas are determined.

[0131] Furthermore, the computer device corresponding to the data processing method of the present application includes a memory and a processor. The memory stores a computer program that can be executed on the processor, and the processor executes the computer program to implement the processing method steps of the present application.

[0132] It is particularly important to note that when distributing optical fibers, the correct orientation must be maintained to ensure that there is no flipping or twisting. At the same time, the position and orientation of the optical fibers must be identified and recorded. These records can provide the necessary information for data processing.

[0133] The number of prefabricated optical fibers in the distributed optical fiber in the present application can be 4, 8 or 16, which are symmetrically distributed with the inner center of the distributed optical fiber, and can be adjusted according to the actual application scenario. As the number of optical fibers increases, the transmission of the distributed optical fiber becomes more accurate and reliable.

[0134] To sum up, the distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring in the embodiment of the present invention is based on the advantages and characteristics of distributed optical fiber, is installed inside the building structure, and combines multiple types of algorithms and data interactions. It can identify the two-dimensional tensile deformation of objects in hidden places, and realize real-time dynamic deformation monitoring and high-precision all-round stress change monitoring of hidden spaces, and then conduct real-time monitoring and advance warning of deformation, damage, deterioration, collapse and other phenomena caused by ground space projects and underground space projects, thereby ensuring the stability and safety of ground space projects and underground space projects.

[0135] The above specific implementation manner cannot be used as a limitation on the protection scope of the present invention. For those skilled in the art, any substitution, improvement or change made to the implementation manner of the present invention falls within the protection scope of the present invention.

[0136] The matters not described in detail in the present invention are all known technologies to those skilled in the art.

Claims

1. A distributed optical fiber data processing method capable of identifying multi-dimensional deformation monitoring, characterized in that: The data processing method comprises the following steps: S1, using multiple control points and mileage data to establish a control network and convert two-dimensional information into three-dimensional information; S2, using stress and strain monitoring data to calculate the three-dimensional deformation data of the distributed optical fiber in an independent coordinate system; S3, calculating and solving the three-dimensional deformation data according to the multiple common point information and the multiple parameter information; S4, judge and extract the strain monitoring data of the distributed optical fiber, remove the noise signal in the original data, and obtain accurate and reliable deformation monitoring information data, so as to realize real-time monitoring and advance warning of deformation phenomena; Using multiple control points and mileage data to establish a control network, converting two-dimensional information into three-dimensional information includes the following steps: S1.1, selecting 3-4 control points of known locations in the distributed optical fiber deployment area, wherein the control points include physical landmarks and identifiable marking points; S1.2, construct an independent optical fiber coordinate system with the X axis parallel to the optical fiber laying direction, the Y axis perpendicular to the optical fiber laying direction, and the Z axis in the mileage direction; S1.3, record the mileage data of the optical fiber, monitor the coordinates of the turning points of the optical fiber layout line, use the interpolation method to obtain the coordinate values ​​of the monitoring points of the optical fiber line, and establish the initial three-dimensional shape of the optical fiber; S1.4, strain calculation along the X-axis direction of the optical fiber: select the optical fiber measuring the X-axis direction in the multi-core optical fiber as the X-axis direction for data processing, and calculate the change of the optical fiber projection on the XOZ plane based on the strain difference of the optical fiber data; strain calculation along the Y-axis direction of the optical fiber: select the optical fiber measuring the Y-axis direction in the multi-core optical fiber as the Y-axis direction for data processing, and calculate the change of the optical fiber projection on the YOZ plane based on the strain difference of the optical fiber data; S1.5, calculating the three-dimensional deformation information of the optical fiber according to the optical fiber projection deformation information on two mutually perpendicular planes XOZ and YOZ; S1.6, denoising the optical fiber data; S1.7, measure the control point data, combine the conversion parameters between the fiber independent coordinate system and the engineering coordinate system, and convert the monitoring data into three-dimensional deformation information under the engineering coordinate system.

2. The distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring according to claim 1 is characterized in that: The distributed optical fiber includes a strain sensing single-mode optical fiber, and a strain transmission layer, a rubber material optical fiber protection layer, a buffer and a strain transmission layer and a buffer layer are sequentially arranged outside the strain sensing single-mode optical fiber; The elastic modulus, Poisson's ratio and compressive strength of the rubber material optical fiber protective layer are similar to those of the object to be measured, and can achieve coordinated deformation with the object to be measured; The material with the buffer and strain transmission layer has a high elastic modulus, can quickly recover to its original shape after being subjected to force, can remain stable under complex stress conditions, absorbs energy when stretched or compressed, and is not easily broken or deformed.

3. The distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring according to claim 1, characterized in that: Using stress-strain monitoring data to calculate the three-dimensional deformation data in the distributed optical fiber coordinate system includes the following steps: S2.1, using a three-dimensional curve to represent the optical fiber deformation curve, and decomposing the three-dimensional curve into an optical fiber horizontal deformation information curve and an optical fiber vertical deformation information curve; S2.2, decompose the optical fiber horizontal deformation information curve into multiple arcs, recorded as P1, P2…P n ; S2.3, perform equivalent calculation on the horizontal deformation segments, for any segmented arc P i , under the premise that the relative position of the optical fiber remains unchanged, any segmented arc P can be obtained i The radius of curvature and the angles of rotation of the two cross sections on the segmented arc around their respective neutral axes, that is: ; Among them, the positive sign represents tension and the negative sign represents compression; S2.4, interpolate the deformation information of different arc segments of the horizontal deformation curve, divide the optical fiber horizontal deformation information curve into several segments, take the nth segment for observation, and set P n and P n+1 are the two endpoints of the nth segment, and the corresponding chord length is l n , O n is the center of the circle corresponding to this segment, and the radius of curvature is R n , P n The angle between the tangent line of the point and the X-axis is θ n , P n+1 The angle between the tangent line of the point and the X-axis is θ n+1 ; Set P n and P n+1 The coordinates of n ,y n ) and (x n+1 ,y n+1 ), the corresponding curvatures are P n , P n+1 ; According to the strain information measured by the distributed sensor, the curvature of each end point is calculated according to the above parameters, and then the deformation information curve of the optical fiber in the horizontal direction is drawn; S2.5, draw the optical fiber vertical deformation information curve according to the above steps, fit the optical fiber morphology using the optical fiber horizontal deformation information, the optical fiber vertical deformation information curve and the optical fiber mileage, and verify the deformation information based on the optical fiber independent coordinate system.

4. The distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring according to claim 1, characterized in that: The calculation and solution of three-dimensional deformation data based on multiple common point information and multiple parameter information includes the following steps: S3.1, select at least 4 optical fiber feature points and use a measuring device to measure the three-dimensional coordinates of the control points; S3.2, using three common point information and a seven-parameter calculation formula to solve the seven-parameter information for converting the optical fiber independent coordinate system to the engineering coordinate system; the seven-parameter information includes a scale factor, an X-direction translation parameter, a Y-direction translation parameter, a Z-direction translation parameter, a rotation angle around the X-axis, a rotation angle around the Y-axis, and a rotation angle around the Z-axis; S3.3, transform the solved seven parameter information in all optical fiber independent coordinate systems to obtain three-dimensional coordinates in the engineering coordinate system.

5. The distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring according to claim 4 is characterized in that: For the three common points, a fourth common point can also be set as a verification point.

6. The distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring according to claim 1, characterized in that: Judging and extracting the strain monitoring data of distributed optical fibers, removing noise signals from the original data, and obtaining accurate and reliable deformation monitoring information data include the following steps: S4.1, using wavelet analysis algorithm to perform noise removal operation on deformation monitoring information data; S4.2, the denoised deformation monitoring information data is smoothed and trimmed using the moving mean algorithm, Savitzky-Goiay algorithm and percentile filtering algorithm.

7. The distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring according to claim 6, characterized in that: The use of wavelet analysis algorithm to remove noise from deformation monitoring information data includes the following steps: S4.1.1, the collected original deformation monitoring information data is divided into two layers by wavelet function; S4.1.2, using different threshold processing methods to process high-frequency signals at each level; S4.1.3, using wavelet reconstruction transform to eliminate noise signals; the wavelet reconstruction transform contains two variables, namely scale parameter a and translation parameter b, scale parameter a corresponds to frequency, and translation parameter b corresponds to time, so wavelet transform can be used for time-frequency analysis to obtain the time-frequency spectrum of the signal; scaling and translating the wavelet function can obtain a wavelet sequence: ； S4.1.4, according to the characteristics and applicability of soft and hard thresholds, select the soft threshold to process the high-frequency signals of each level, reconstruct the processed signals and low-frequency signals, and obtain the denoised signals.

8. The distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring according to claim 6, characterized in that: The smoothing and trimming of the denoised deformation monitoring information data using the moving mean algorithm, Savitzky-Goiay algorithm and percentile filtering algorithm includes the following steps: S4.2.1, set a set of data in a window as x[i], i=[-m,m], i takes 2m+1 consecutive integer values, and construct an n-order polynomial to fit this set of data, n≤2m+1; S4.2.2, solve the residual sum of squares between the fitted data points and the original data points to ensure the stability and accuracy of the deformation monitoring information data.

9. The distributed optical fiber data processing method with the ability to identify multi-dimensional deformation monitoring according to claim 1, characterized in that: The data processing system corresponding to the data processing method includes: A conversion module, the conversion module is used to establish a control network using multiple control points and mileage data, and convert two-dimensional information into three-dimensional information; A summary module, the summary module is used to calculate the three-dimensional deformation data of the distributed optical fiber in an independent coordinate system using the stress and strain monitoring data; A calculation module, the calculation module is used to calculate and solve the three-dimensional deformation data according to multiple common point information and multiple parameter information; The analysis module is used to judge and extract the strain monitoring data of the distributed optical fiber, remove the noise signal in the original data, and obtain accurate and reliable deformation monitoring information data, thereby realizing real-time monitoring and advance warning of deformation phenomena.

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