Hydraulic engineering dam body deformation monitoring method and system

Abstract

The invention relates to the technical field of building deformation monitoring, in particular to a water conservancy project dam body deformation monitoring method and system, and the method comprises the steps: obtaining voltage time sequence signals outputted by optical fiber stress sensors of a plurality of monitoring points in a monitoring region, fusing the differences of any two voltage time sequence signals in a time domain and a frequency domain, and obtaining the deformation of a dam body. The optical fiber stretching degree of the monitoring area is obtained, then the overall temperature abnormal degree of the monitoring area is combined, the output quantity in the process of converting the grating wavelength into the electric signal in the optical fiber stress sensor is corrected, and the overall temperature abnormal degree is obtained through the temperature abnormal value of each monitoring point; electric signal changes brought by temperature changes to the optical fiber stress sensors can be eliminated, drift compensation of detection signals of the optical fiber stress sensors is achieved, error influences are eliminated, and the accuracy of dam body deformation monitoring of the water conservancy project is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of building deformation monitoring, and in particular to a method and system for monitoring deformation of a dam body of a water conservancy project. Background Art

[0002] The dam in water conservancy projects is usually used to intercept water flow to form reservoirs, regulate flow, generate electricity, irrigate, etc. The shape and structure of the dam body are designed according to the specific topography, hydrological conditions and engineering needs. It can generally be divided into the following main types: gravity dam, arch dam, earth-rock dam and concrete panel rockfill dam. Among them, the basic principle of the dam body is mostly to use its own weight to stabilize the retaining wall structure, usually in a straight line or arc shape, and generally in a trapezoidal shape when viewed from the side. It is suitable for areas with hard geology and high foundation bearing capacity; or it is built with earth and stone materials, usually with a trapezoidal cross-section, including earth dams and stone dams, suitable for a wide range of terrain conditions.

[0003] The deformation monitoring of the dam body is extremely important. In the existing technology, the deformation monitoring methods of the dam body mainly include: GPS monitoring: through the GPS equipment installed on the dam body, the displacement and deformation of the dam body are monitored in real time; leveling measurement: using the level to regularly monitor the landmark points of the dam body to obtain vertical displacement data; total station monitoring: using the total station to measure the displacement of the surface layer or specific position of the dam body to obtain three-dimensional position information; ground stress and strain monitoring: burying strain gauges and strain gauges inside the dam body to directly measure the stress and deformation state of the dam body.

[0004] Fiber optic sensing technology is very useful in health monitoring of dams and other large structures due to its corrosion resistance, high sensitivity, passivity and ability to perform long-distance distributed measurements. In strain monitoring, fiber optic stress sensors are usually used to detect the deformation of the dam.

[0005] In the use of optical fiber stress sensors to detect dam deformation, based on the conversion relationship between the optical signal and the electrical signal of the optical fiber stress sensor, due to the complexity of the environment, factors such as different weather conditions and changes in light will cause temperature fluctuations in the dam detection area. These temperature changes will also affect the changes in the electrical signals of the optical fiber stress sensor, thereby affecting the accuracy of the real stress change signal, thereby reducing the accuracy of dam deformation monitoring. Summary of the invention

[0006] In order to solve the technical problem of low accuracy of deformation monitoring of dam bodies of water conservancy projects using existing optical fiber stress sensors, the purpose of the present invention is to provide a method and system for monitoring deformation of dam bodies of water conservancy projects. The technical solutions adopted are as follows: In a first aspect of the present invention, a method for monitoring deformation of a dam body of a water conservancy project is provided, comprising: Obtaining voltage timing signals output by optical fiber stress sensors at multiple monitoring points within a monitoring area; Fusion of differences between any two of the voltage time series signals in the time domain and the frequency domain to obtain the optical fiber stretching degree of the monitoring area; According to the degree of optical fiber stretching in the monitoring area and the overall temperature anomaly in the monitoring area, the output of the grating wavelength in the optical fiber stress sensor is corrected during the conversion of the electrical signal; the overall temperature anomaly is obtained from the temperature anomaly value of each monitoring point.

[0007] In an exemplary embodiment, the fusing of the differences between any two of the voltage time series signals in the time domain and the frequency domain to obtain the optical fiber stretching degree of the monitoring area includes: According to the difference between the voltage values ​​corresponding to the extreme points in any two of the voltage time series signals, the amplitude linear displacement of the monitoring area is obtained; Obtaining the degree of abnormality of the electrical data characteristics of the monitoring area according to the difference in the number of extreme value points in any two of the voltage time series signals and the phase difference in the frequency domain signal; The degree of optical fiber stretching in the monitoring area is obtained according to the amplitude linear displacement and the degree of abnormality of the electrical data characteristics; the amplitude linear displacement and the degree of abnormality of the electrical data characteristics are both proportional to the degree of optical fiber stretching.

[0008] In an exemplary embodiment, obtaining the amplitude linear displacement of the monitoring area according to the difference between the voltage values ​​corresponding to the extreme points in any two of the voltage time series signals includes: Respectively obtain a maximum value set of a first voltage timing signal and a second voltage timing signal, and obtain a time union of the maximum value sets of the first voltage timing signal and the second voltage timing signal; the first voltage timing signal and the second voltage timing signal are any two voltage timing signals; Acquire the moments and collect the voltage value differences in the first voltage timing signal and the second voltage timing signal at each moment; The voltage value differences corresponding to the moments are integrated and concentrated to obtain the amplitude linear displacement of the monitoring area.

[0009] In an exemplary embodiment, the fusing of the moments and concentrating the voltage value differences corresponding to all moments to obtain the amplitude linear displacement of the monitoring area includes: Calculate the voltage value difference average value of the voltage value differences corresponding to the moment and all moments in the set to obtain the overall voltage difference between the first voltage timing signal and the second voltage timing signal; The average value of the overall voltage difference of all any two voltage time series signals is calculated and normalized to obtain the amplitude linear displacement of the monitoring area.

[0010] In an exemplary embodiment, obtaining the abnormality degree of the electrical data characteristics of the monitoring area according to the difference in the number of extreme points in any two of the voltage time series signals and the phase difference in the frequency domain signal includes: Obtaining the number of maximum values ​​of a first voltage timing signal and a second voltage timing signal, and obtaining the difference in the number of maximum values ​​between the first voltage timing signal and the second voltage timing signal; the first voltage timing signal and the second voltage timing signal are any two voltage timing signals; Converting the first voltage timing signal and the second voltage timing signal into frequency domain signals respectively, and obtaining a phase difference between the frequency domain signals of the first voltage timing signal and the second voltage timing signal; The maximum value quantity difference and the phase difference are integrated to obtain the abnormal degree of the electrical data characteristics of the monitoring area.

[0011] In an exemplary embodiment, the fusing of the maximum value quantity difference and the phase difference to obtain the abnormality degree of the electrical data characteristic of the monitoring area includes: Calculating the product of the maximum value quantity difference and the phase difference between the first voltage timing signal and the second voltage timing signal to obtain the data sub-abnormality degree corresponding to the first voltage timing signal and the second voltage timing signal; The average value of the data sub-abnormality levels corresponding to any two voltage time series signals is calculated and normalized to obtain the abnormality level of the electrical data characteristics of the monitoring area.

[0012] In an exemplary embodiment, the temperature anomaly value of the monitoring point is the isolated forest score value of the monitoring point; and the overall temperature anomaly degree is the average of the isolated forest score values ​​of all monitoring points.

[0013] In an exemplary embodiment, the output amount of the optical fiber stress sensor in the process of converting the grating wavelength into an electrical signal is corrected according to the degree of optical fiber stretching in the monitoring area and the degree of overall temperature anomaly in the monitoring area, including: Obtaining a correction coefficient according to the degree of optical fiber stretching and the degree of overall temperature anomaly in the monitoring area; According to the correction coefficient and the original output amount in the process of converting the grating wavelength in the optical fiber stress sensor into an electrical signal, a corrected output amount in the process of converting the grating wavelength in the optical fiber stress sensor into an electrical signal is obtained.

[0014] In an exemplary embodiment, the water conservancy project dam deformation monitoring method further includes: Comparing the overall temperature abnormality with a preset temperature abnormality threshold; If the overall temperature abnormality is greater than the preset temperature abnormality threshold, a temperature interference alarm instruction is output.

[0015] In a second aspect of the present invention, a water conservancy project dam deformation monitoring system is provided, comprising: a memory and a processor; the memory is connected to the processor; the memory is used to store program instructions; the processor is used to implement the above-mentioned water conservancy project dam deformation monitoring method when the program instructions are executed.

[0016] The present invention has the following beneficial effects: multiple monitoring points are set in the monitoring area, each monitoring point is provided with an optical fiber stress sensor, each monitoring point also obtains the temperature, and simultaneously analyzes the characteristics of the voltage timing signal output by the optical fiber stress sensors of any two monitoring points in the time domain and the frequency domain, and obtains the optical fiber stretching degree of the monitoring area according to the difference in the characteristics in the time domain and the frequency domain, and finally, according to the optical fiber stretching degree of the monitoring area and the overall temperature anomaly degree of the monitoring area with respect to the temperature, the output amount in the process of converting the grating wavelength into the electrical signal in the optical fiber stress sensor is corrected, which can eliminate the electrical signal change of the optical fiber stress sensor caused by the temperature change, realize the drift compensation of the detection signal of the optical fiber stress sensor, eliminate the error influence, and improve the accuracy of the dam deformation monitoring of the water conservancy project. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a flow chart of a method for monitoring deformation of a dam body of a water conservancy project provided by an embodiment of the present invention; Figure 2 is a flow chart for obtaining the degree of optical fiber stretching provided by one embodiment of the present invention; Figure 3 is a flowchart for obtaining amplitude linear displacement provided by an embodiment of the present invention; Figure 4 It is a specific calculation process diagram of amplitude linear displacement provided by one embodiment of the present invention; Figure 5 is a flow chart for obtaining the abnormality degree of electrical data characteristics provided by one embodiment of the present invention; Figure 6 It is a specific calculation process diagram of the abnormality degree of electrical data characteristics provided by an embodiment of the present invention; Figure 7 is a correction process diagram provided by an embodiment of the present invention; Figure 8 A method for monitoring deformation of a dam body of a water conservancy project provided by an embodiment of the present invention also includes a flow chart of steps. DETAILED DESCRIPTION

[0018] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. The data and information collected in this application have been obtained with full consent and authorization, and the collection, use and processing of relevant information must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0020] The application scenario of a method for monitoring deformation of a dam body of a water conservancy project provided in this embodiment is: determining the monitoring area for deformation monitoring of the dam body of a water conservancy project, and the monitoring area is usually the key area of ​​the dam body of a water conservancy project. In the dam body of a water conservancy project, one monitoring area or multiple monitoring areas can be set. In an exemplary embodiment, the structure of the dam body is often complex and the bearing capacity is uneven, so the monitoring area can be selected according to its different structural functions and importance. The divided monitoring areas include: the core area of ​​the dam body: the base, middle and upper parts of the dam body; the corners and joints of the dam body: the corners of the dam body are places where mechanical forces are greater; the spillway, drainage system and anti-seepage area of ​​the dam body: these areas involve changes in the water pressure of the dam body.

[0021] Multiple monitoring points are set up in the monitoring area. The number and layout of the monitoring points are set according to actual needs, such as grid layout. Each monitoring point is equipped with a fiber stress sensor and a temperature sensor. The fiber stress sensor is a fiber grating sensor used to check stress deformation and is used to monitor the changes in physical quantities such as stress and strain at the corresponding monitoring point in real time; the temperature sensor is used to detect the temperature of the corresponding monitoring point.

[0022] In an exemplary embodiment, the sensitivity of the optical fiber stress sensor is generally between 1-2 pm / με (picometer / microstrain). When the strain change is set to 10με, the wavelength change is about 10-20pm; the wavelength range is generally 1500-1600 nm, and the common reflection wavelength is 1550 nm; the accuracy is generally within 1 pm, which can accurately reflect small-scale deformation; the operating temperature is -40°C to 85°C, which is suitable for different climates and environmental conditions.

[0023] The temperature change of the temperature sensor will affect the reading of the optical fiber stress sensor, so it is necessary to configure the temperature sensor for compensation. The sensitivity of the temperature sensor is 0.1°C to 0.5°C, which can be reflected by the temperature sensor; the operating temperature range of the temperature sensor is -40°C to 85°C; the accuracy of the temperature sensor is ±0.1°C.

[0024] Each optical fiber stress sensor transmits a signal through an optical fiber, and a temperature sensor transmits a signal through a data transmission line or through a wireless communication module.

[0025] like Figure 1 As shown, a method for monitoring deformation of a dam in a water conservancy project provided in this embodiment includes the following steps: Step 1: Obtain the voltage timing signals output by the optical fiber stress sensors at multiple monitoring points in the monitoring area.

[0026] Step 2: Fusion the differences between any two voltage timing signals in the time domain and frequency domain to obtain the optical fiber stretching degree in the monitoring area.

[0027] Step 3: According to the degree of optical fiber stretching in the monitoring area and the overall temperature anomaly in the monitoring area, the output of the grating wavelength in the optical fiber stress sensor is corrected in the process of converting the electrical signal; the overall temperature anomaly is obtained from the temperature anomaly value of each monitoring point.

[0028] The following is a detailed description of the various steps of a method for monitoring dam deformation of a water conservancy project provided by this embodiment in conjunction with the accompanying drawings.

[0029] Step 1: Obtain the voltage timing signals output by the optical fiber stress sensors at multiple monitoring points in the monitoring area.

[0030] The optical fiber stress sensor is used to convert the detected optical signal into an electrical signal. Then, the voltage timing signal output by the optical fiber stress sensor is the electrical signal output by the optical fiber stress sensor.

[0031] The sampling period (i.e., sampling frequency) of the optical fiber stress sensor is set according to actual needs. Moreover, the sampling period of the optical fiber stress sensors at all monitoring points is the same, and the optical fiber stress sensors at all monitoring points are sampled synchronously, that is, at a certain moment, the voltage signal output by the optical fiber stress sensor at each monitoring point can be obtained.

[0032] In an exemplary embodiment, a monitoring time period is set, and a method for monitoring deformation of a dam body of a water conservancy project provided in this embodiment is used to correct the output of the optical fiber stress sensor according to the data of the monitoring time period. The duration of the monitoring time period, that is, the number of moments included therein, is set according to actual needs.

[0033] According to the voltage signal at each moment, the voltage time series signal output by the optical fiber stress sensor at the monitoring point is obtained. The voltage time series signal is obtained by arranging the voltage signals at each moment in time series. Thus, the voltage time series signal output by the optical fiber stress sensor at each monitoring point is obtained. The voltage time series signal is a signal in which the voltage amplitude changes with time. It is manifested as a non-periodic signal with a limited time series. The optical fiber wavelength and other parameters are captured through the non-periodic signal with a limited time series, thereby monitoring the stress value of the monitoring point. Different monitoring points have different detection results of optical fiber stress sensors.

[0034] The temperature sensor at the monitoring point obtains the temperature value of the monitoring point. It should be understood that the temperature time series signal of the monitoring point can also be obtained by using the same sampling frequency of the above-mentioned optical fiber stress sensor. In this embodiment, the average value of the temperature value in the temperature time series signal detected by the temperature sensor at the monitoring point is calculated, and the average value is used as the temperature value of the monitoring point. Thus, the temperature value of each monitoring point is obtained.

[0035] Furthermore, the reason for collecting the temperature value of each monitoring point is explained: at different monitoring points, the temperature of the monitoring point may fluctuate due to the influence of light, shadow or weather environment, and the fluctuating temperature will affect the stress electrical signal value of the monitoring point, thereby generating corresponding errors.

[0036] The temperature values ​​collected at each monitoring point are used for subsequent comparison and compensation calculations, and participate in the calculation of the grating wavelength drift compensation of the optical fiber stress sensor.

[0037] Step 2: Fusion the differences between any two voltage timing signals in the time domain and frequency domain to obtain the optical fiber stretching degree in the monitoring area.

[0038] In general, when there is no deformation in the dam body, the voltage time series signal obtained by the optical fiber stress sensor will not produce obvious changes, that is, it has relatively similar and regular characteristics at different times. When the dam body is deformed, stress changes occur in some areas of the dam body. When the stress increases, the optical fiber of the optical fiber stress sensor is stretched, and the Bragg grating spacing increases, causing the central wavelength of the reflected light to drift toward the long-wave direction (red shift). The wavelength drift can be converted into a corresponding change in the voltage signal by the photoelectric detector of the optical fiber stress sensor. Therefore, the amplitude of the voltage signal will change relative to the baseline signal. If it is a linear spectrum demodulator, the wavelength change will cause a linear change in the output voltage amplitude. Then, when the voltage time series signal at the monitoring point changes, that is, its voltage amplitude has a certain linear drift, and the phase value also changes, it can be considered as a change in the stress value caused by the suspected deformation. Therefore, the differences in the voltage time series signals of any two monitoring points in the time domain and frequency domain are analyzed, and these differences of all two monitoring points are integrated to obtain the degree of optical fiber stretching in the monitoring area.

[0039] In an exemplary embodiment, Figure 2 As shown, a specific process for obtaining the optical fiber stretching degree of the monitoring area is given as follows: Step 2-1: According to the difference in voltage values ​​corresponding to the extreme points in any two voltage time series signals, the amplitude linear displacement of the monitoring area is obtained.

[0040] By analyzing the difference in voltage values ​​corresponding to the extreme points in the voltage timing signals of any two monitoring points, the linear displacement of the voltage amplitude of the voltage timing signals of the two monitoring points is obtained. Then, the linear displacement of the amplitude of the voltage of all two monitoring points is combined to obtain the linear displacement of the amplitude of the monitoring area.

[0041] In an exemplary embodiment, Figure 3 As shown, a specific process of obtaining the amplitude linear displacement is given as follows: Step 2-1-1: respectively obtain a set of maximum values ​​of the first voltage timing signal and the second voltage timing signal, and obtain a time union of the set of maximum values ​​of the first voltage timing signal and the second voltage timing signal.

[0042] For ease of explanation, assume that the first monitoring point and the second monitoring point are any two monitoring points, the first voltage timing signal is the voltage timing signal of the first monitoring point, and the second voltage timing signal is the voltage timing signal of the second monitoring point. Then, the first voltage timing signal and the second voltage timing signal are any two voltage timing signals.

[0043] The maximum values ​​in the first voltage timing signal are obtained, and the maximum values ​​are sorted according to the moments of the maximum values ​​in the first voltage timing signal to obtain a maximum value set of the first voltage timing signal, which is defined as a first maximum value set. Then, the moments corresponding to the maximum values ​​in the first maximum value set are obtained to obtain a first moment set.

[0044] Similarly, the maximum values ​​in the first voltage timing signal are obtained, and the maximum values ​​are sorted according to the moments of the maximum values ​​in the second voltage timing signal to obtain a maximum value set of the second voltage timing signal, which is defined as a second maximum value set. Then, the moments corresponding to the maximum values ​​in the second maximum value set are obtained to obtain a second moment set.

[0045] Then, the union of the first moment set and the second moment set is obtained to obtain the moment union. For example, if the first moment set corresponding to the first maximum value set is: t12, t17, t23, t30, t39, t45, and the second moment set corresponding to the second maximum value set is: t10, t16, t23, t32, t39, t46, then the moment union of the first moment set and the second moment set is: t10, t12, t16, t17, t23, t30, t32, t39, t45, t46.

[0046] The maximum value can reflect the characteristic of the voltage timing signal, and by adopting the union method, all the maximum values ​​in the two voltage timing signals can be considered at the same time, thereby improving the accuracy of data processing.

[0047] Step 2-1-2: Obtain the moments and collect the voltage value differences in the first voltage timing signal and the second voltage timing signal at each moment.

[0048] The voltage values ​​in the first voltage timing signal at each moment are acquired and concentrated, and the voltage values ​​in the second voltage timing signal at each moment are acquired and concentrated.

[0049] Then, the voltage value difference of the voltage values ​​in the first voltage timing signal and the second voltage timing signal at each moment in the time and set is calculated to obtain the voltage value difference corresponding to each moment. For example, if any moment in the time and set is set as the i-th moment, the calculation formula for the voltage value difference corresponding to the i-th moment is as follows: ; in, is the voltage value of the ith moment in the first voltage time series signal in the time series set, that is, the voltage value of the ith moment in the time series set in the first voltage time series signal; is the voltage value of the ith moment in the moment set in the second voltage timing signal, that is, the voltage value of the ith moment in the moment set in the second voltage timing signal; is the voltage value difference between the voltage values ​​in the first voltage timing signal and the second voltage timing signal at the i-th moment in the moment set.

[0050] Step 2-1-3: Fusion moment and concentration of voltage value differences corresponding to all moments to obtain the amplitude linear displacement of the monitoring area.

[0051] The overall voltage difference between the first voltage timing signal and the second voltage timing signal is obtained by fusing the moments and concentrating the voltage value differences corresponding to all moments, and then the overall voltage difference between any two voltage timing signals is combined to obtain the amplitude linear displacement of the monitoring area.

[0052] In an exemplary embodiment, Figure 4 As shown, a specific calculation process of amplitude linear displacement is given as follows: Step 2-1-3-1: Calculate the average voltage value difference of the voltage value differences corresponding to all the moments in the moment and obtain the overall voltage difference between the first voltage timing signal and the second voltage timing signal.

[0053] The voltage value difference average value of the voltage value difference corresponding to all the moments in the moment is calculated and concentrated to obtain the overall voltage difference between the first voltage timing signal and the second voltage timing signal, that is, the voltage amplitude difference characteristic of the first voltage timing signal and the second voltage timing signal. The calculation formula is as follows: ; in, is the overall voltage difference between the first voltage timing signal and the second voltage timing signal, and I is the number of moments in the moment set.

[0054] Step 2-1-3-2: Calculate the average value of the overall voltage difference between any two voltage timing signals and normalize them to obtain the amplitude linear displacement of the monitoring area.

[0055] Through step 2-1-3-1, the overall voltage difference corresponding to each voltage timing signal pair (a voltage timing signal pair consists of two voltage timing signals) in the monitoring area can be obtained, and then the overall voltage differences corresponding to all voltage timing signal pairs in the monitoring area are averaged, and then the average value is normalized. The normalized result is the amplitude linear displacement of the monitoring area.

[0056] It should be understood that the normalization in this embodiment can be specifically set according to actual conditions, for example, a linear normalization method, such as a maximum and minimum value normalization method, or the following common methods: , It represents the processing object, and exp represents the exponential function with the natural constant e as the base.

[0057] By analyzing the amplitude difference characteristics of the voltage signal between different monitoring points in the monitoring area, the amplitude linear displacement of the monitoring area is determined. When the overall voltage difference between different monitoring points is smaller, that is, the amplitude difference characteristics are less obvious, the amplitude linear displacement of the monitoring area is lower, reflecting that in this monitoring area, the possibility of changes in the voltage signal due to changes in stress values ​​caused by dam deformation is lower. Conversely, the larger the amplitude linear displacement value of the monitoring area, the higher the linear amount of the voltage data in the voltage amplitude dimension, and the higher the possibility of dam deformation.

[0058] Step 2-2: According to the difference in the number of extreme points in any two voltage time series signals and the phase difference in the frequency domain signal, the abnormality degree of the electrical data characteristics of the monitoring area is obtained.

[0059] The difference of a single extreme point cannot fully reflect the linear quantity of the time-series finite data in the monitoring area, and it is also necessary to combine the phase characteristics of the frequency domain signal, because phase modulation is used as a measurement method in optical fiber stress sensors. The phase drift of the light wave caused by stress changes is converted into a phase change in the electrical signal through interferometric measurement. The phase change is used as a technical means to compensate or improve the measurement accuracy.

[0060] According to the difference in the number of extreme points in any two voltage time series signals and the phase difference in the frequency domain signal, the abnormal degree of the electrical data characteristics of the monitoring area is obtained.

[0061] In an exemplary embodiment, Figure 5 As shown, a specific process for obtaining the abnormality degree of electrical data characteristics is given as follows: Step 2-2-1: Obtain the number of maximum values ​​of the first voltage timing signal and the second voltage timing signal, and obtain the difference in the number of maximum values ​​of the first voltage timing signal and the second voltage timing signal.

[0062] The number of maximum values ​​in the first maximum value set is obtained to obtain the first maximum value number; the number of maximum values ​​in the second maximum value set is obtained to obtain the second maximum value number.

[0063] The maximum value difference between the first maximum value number and the second maximum value number is obtained. In an exemplary embodiment, the absolute value of the difference between the first maximum value number and the second maximum value number is calculated as the maximum value difference between the first maximum value number and the second maximum value number.

[0064] Step 2-2-2: Convert the first voltage timing signal and the second voltage timing signal into frequency domain signals respectively, and obtain the phase difference between the frequency domain signals of the first voltage timing signal and the second voltage timing signal.

[0065] Since the voltage timing signal is a time domain signal, the first voltage timing signal is converted into a first frequency domain signal, and the phase of the first frequency domain signal is obtained, which is defined as the first phase; similarly, the second voltage timing signal is converted into a second frequency domain signal, and the phase of the second frequency domain signal is obtained, which is defined as the second phase.

[0066] The phase difference between the first phase and the second phase is obtained. In an exemplary embodiment, the absolute value of the difference between the first phase and the second phase is calculated as the phase difference between the first phase and the second phase.

[0067] The phase difference can reflect the degree of drift in the optical fiber sensing process, and then reflect whether the dam body is deformed at different monitoring points, resulting in stress difference. The larger the phase difference, the higher the difference in voltage data at the corresponding two monitoring points. The phase difference reflects the difference in optical signals, and then it can be concluded that stress changes may occur in the monitoring area.

[0068] Step 2-2-3: Fusion the maximum value quantity difference and phase difference to obtain the abnormality degree of the electrical data characteristics of the monitoring area.

[0069] By fusion analysis of the maximum value quantity difference and phase difference of the voltage time series signal of any two monitoring points, the abnormal degree of the electrical data characteristics of the monitoring area can be obtained. In an exemplary embodiment, Figure 6 As shown, a specific calculation process of the abnormal degree of electrical data characteristics is given as follows: Step 2-2-3-1: Calculate the product of the maximum value quantity difference and the phase difference of the first voltage timing signal and the second voltage timing signal to obtain the data sub-abnormality degree corresponding to the first voltage timing signal and the second voltage timing signal.

[0070] The calculation formula for the data sub-abnormality degree corresponding to the first voltage timing signal and the second voltage timing signal is as follows: ; in, is the degree of abnormality of the data corresponding to the first voltage timing signal and the second voltage timing signal, is the difference in the number of maximum values ​​corresponding to the first voltage timing signal and the second voltage timing signal, is the phase difference between the first voltage timing signal and the second voltage timing signal.

[0071] Step 2-2-3-2: Calculate the average value of the data sub-abnormality levels corresponding to any two voltage timing signals and normalize them to obtain the abnormality level of the electrical data characteristics of the monitoring area.

[0072] Through step 2-2-3-1, the data sub-abnormality degree corresponding to each voltage timing signal pair (a voltage timing signal pair consists of two voltage timing signals) in the monitoring area can be obtained, and then the data sub-abnormality degrees corresponding to all voltage timing signal pairs in the monitoring area are averaged, and finally the average value is normalized, and the normalized result obtained is the abnormality degree of the electrical data characteristics of the monitoring area.

[0073] Step 2-3: According to the amplitude linear displacement and the abnormal degree of the electrical data characteristics, the optical fiber stretching degree of the monitoring area is obtained.

[0074] According to the amplitude linear displacement and the degree of abnormality of the electrical data characteristics, the degree of optical fiber stretching in the monitoring area is obtained, and the degree of optical fiber stretching is proportional to the amplitude linear displacement, and the degree of optical fiber stretching is proportional to the degree of abnormality of the electrical data characteristics. In an exemplary embodiment, the product of the amplitude linear displacement and the degree of abnormality of the electrical data characteristics in the monitoring area is calculated as the degree of optical fiber stretching in the monitoring area. The greater the degree of optical fiber stretching in the monitoring area, the higher the linear amount of its light wave electrical data in the monitoring area, that is, the higher the possibility of stress abnormality caused by the deformation of the dam body.

[0075] In an exemplary embodiment, a fiber stretching degree threshold (such as 0.8) may be preset. When the fiber stretching degree in the monitoring area is greater than the fiber stretching degree threshold, it is determined that there is a high probability that the dam body has undergone suspected deformation.

[0076] Step 3: According to the degree of optical fiber stretching in the monitoring area and the overall temperature anomaly in the monitoring area, the output of the grating wavelength in the optical fiber stress sensor is corrected in the process of converting the electrical signal; the overall temperature anomaly is obtained from the temperature anomaly value of each monitoring point.

[0077] The degree of fiber stretching in the monitoring area is theoretically in conflict with the change in temperature in the monitoring area, because both dam deformation (such as deformation caused by water level changes in the reservoir or earthquakes) and temperature changes will cause the wavelength of the fiber Bragg grating to drift, which is mainly manifested as a change in the reflection wavelength of the grating. The change in wavelength can indeed reflect the change in the corresponding physical quantity (such as stress or temperature). Therefore, in practical applications, the effects of stress and temperature are intertwined, so it is necessary to distinguish between the two, especially when detecting electrical signals.

[0078] Therefore, it is necessary to obtain the overall temperature anomaly degree of the monitoring area, that is, the temperature jump value of the monitoring area, in order to analyze the interference degree of the temperature value of the monitoring area on the optical fiber stretching degree.

[0079] First, obtain the temperature anomaly value of each monitoring point, and the temperature anomaly value is used to characterize the temperature anomaly of the monitoring point. In an exemplary embodiment, the temperature anomaly value of the monitoring point is the isolation forest score value of the monitoring point. It should be understood that the isolation forest algorithm is used to calculate the isolation forest score value of the temperature value of each monitoring point using the temperature values ​​of all monitoring points as samples. The higher the isolation forest score value, the higher the degree of isolation and the more abnormal the temperature value. It should be understood that when the temperature value of a single monitoring point does not have an isolated characteristic, its isolation forest score value is 0. In other embodiments, other anomaly detection algorithms can also be used to obtain the temperature anomaly value of each monitoring point. If the numerical range of the temperature anomaly value of each monitoring point initially obtained does not meet the numerical range of 0-1, it is necessary to normalize and include the temperature anomaly value in the numerical range of 0-1 to facilitate subsequent processing.

[0080] The overall temperature anomaly degree is obtained from the temperature anomaly values ​​of each monitoring point. In an exemplary embodiment, the average value of the isolated forest score values ​​of all monitoring points is calculated, and the average value is the overall temperature anomaly degree of the monitoring area.

[0081] Then, according to the degree of optical fiber stretching in the monitoring area and the degree of overall temperature anomaly in the monitoring area, the output of the optical fiber stress sensor in the process of converting the grating wavelength into an electrical signal is corrected. In an exemplary embodiment, Figure 7 As shown, a specific correction process is given as follows: Step 3-1: Obtain a correction factor based on the degree of optical fiber stretching and the overall temperature anomaly in the monitoring area.

[0082] According to the degree of optical fiber stretching and overall temperature anomaly in the monitoring area, the correction coefficient is obtained. This correction coefficient refers to the weight value corresponding to each data in the process of transferring the grating wavelength drift to the electrical signal, that is, the grating wavelength drift compensation weight coefficient.

[0083] In an exemplary embodiment, the product of the optical fiber stretching degree and the overall temperature anomaly degree in the monitoring area is calculated as the correction factor.

[0084] Step 3-2: According to the correction coefficient and the original output amount in the process of converting the grating wavelength into the electrical signal in the optical fiber stress sensor, the corrected output amount in the process of converting the grating wavelength into the electrical signal in the optical fiber stress sensor is obtained.

[0085] In an exemplary embodiment, the correction calculation method is given as follows: ; in, It indicates the corrected output in the process of converting the grating wavelength into an electrical signal in the optical fiber stress sensor. It represents the original output of the optical fiber stress sensor in the process of converting the grating wavelength into an electrical signal, and r is the correction coefficient.

[0086] On the basis of the original output, a correction coefficient is added to reduce the data fluctuation at different monitoring points by lowering the electrical data value, thereby preventing the light wave drift caused by temperature changes, which may lead to abnormal stress judgment.

[0087] In an exemplary embodiment, Figure 8 As shown, the method for monitoring deformation of a dam body of a water conservancy project provided in this embodiment also includes: Step 4: Compare the overall temperature abnormality with a preset temperature abnormality threshold; Step 5: If the overall temperature abnormality is greater than the preset temperature abnormality threshold, a temperature disturbance alarm instruction is output.

[0088] The higher the overall temperature anomaly is, the stronger the temperature interference received by the optical fiber stretching in the optical fiber stress sensor is. Therefore, a temperature anomaly threshold is preset, and the preset temperature anomaly threshold is set according to actual needs, such as 0.6.

[0089] If the overall temperature anomaly is greater than the preset temperature anomaly threshold, it is determined that there is strong temperature interference in the optical fiber stretching in the optical fiber stress sensor. Then, a temperature interference alarm instruction is output for the staff to obtain in time so that relevant solutions can be taken in time.

[0090] In an exemplary embodiment, in subsequent applications, the dam stress value of each monitoring area is obtained according to the corrected output in the process of converting the grating wavelength into an electrical signal in the optical fiber stress sensor. The deformation result of the dam body is determined according to the dam body stress value. This part is the prior art and is briefly stated as follows. The process is: Stress-deformation relationship analysis: According to the mechanical properties of the dam material (Young's modulus) and the geometric shape of the dam, the relationship between stress and deformation is established. Usually, the finite element analysis (FEA) method can be used to simulate the stress distribution in different monitoring areas and calculate the corresponding deformation in combination with the actual monitored stress data.

[0091] Deformation calculation: Deformation calculation is performed through the relationship formula between stress and deformation (using the stress-strain formula in elastic mechanics). The stress data of each monitoring point is analyzed to calculate the deformation value (displacement, deformation, etc.) of the point.

[0092] Overall deformation assessment of the dam body: Integrate the deformation results of each monitoring area to analyze the deformation trend and degree of the entire dam body. Usually, weighted average, integration and other methods are used to synthesize the deformation of the monitoring area into the overall deformation.

[0093] The method for monitoring deformation of a dam body of a water conservancy project provided in this embodiment has the following specific advantages: 1) The monitoring area of ​​the dam body is monitored by optical fiber sensing technology, and the data change results are analyzed to obtain the deformation results of the dam body, thereby eliminating the problem of confusion caused by temperature differences; 2) In optical fiber sensing technology, by converting light waves into electrical signals for analysis, temperature changes will also bring about certain changes in electrical signals. By analyzing temperature anomalies and combining the temperature anomalies with the degree of optical fiber stretching, the corresponding drift compensation value of the light wave conversion electrical signal process is obtained to eliminate the influence of errors; 3) Based on the error-free stress change results in the monitoring area, the deformation amount and deformation possibility of the dam body under the water conservancy project can be analyzed.

[0094] This embodiment also provides a water conservancy project dam deformation monitoring system, including: a memory and a processor; the memory is connected to the processor, and the memory is used to store program instructions; the processor is used to implement the steps in the above-mentioned water conservancy project dam deformation monitoring method embodiment when the program instructions are executed.

[0095] In an exemplary embodiment, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps in the above-mentioned embodiment of the method for monitoring deformation of a dam body of a water conservancy project.

[0096] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0097] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

Claims

1. A method for monitoring deformation of a dam in a water conservancy project, characterized in that: include: Obtaining voltage timing signals output by optical fiber stress sensors at multiple monitoring points within a monitoring area; Fusion of differences between any two of the voltage time series signals in the time domain and the frequency domain to obtain the optical fiber stretching degree of the monitoring area; According to the degree of optical fiber stretching in the monitoring area and the overall temperature anomaly in the monitoring area, the output of the grating wavelength in the optical fiber stress sensor is corrected during the conversion of the electrical signal; the overall temperature anomaly is obtained from the temperature anomaly value of each monitoring point.

2. A method for monitoring deformation of a dam in a water conservancy project according to claim 1, characterized in that: The fusing the differences between any two of the voltage time series signals in the time domain and the frequency domain to obtain the optical fiber stretching degree of the monitoring area includes: According to the difference between the voltage values ​​corresponding to the extreme points in any two of the voltage time series signals, the amplitude linear displacement of the monitoring area is obtained; Obtaining the degree of abnormality of the electrical data characteristics of the monitoring area according to the difference in the number of extreme value points in any two of the voltage time series signals and the phase difference in the frequency domain signal; The degree of optical fiber stretching in the monitoring area is obtained according to the amplitude linear displacement and the degree of abnormality of the electrical data characteristics; the amplitude linear displacement and the degree of abnormality of the electrical data characteristics are both proportional to the degree of optical fiber stretching.

3. A method for monitoring deformation of a dam in a hydraulic engineering project as claimed in claim 2, characterized in that: The obtaining of the amplitude linear displacement of the monitoring area according to the difference between the voltage values ​​corresponding to the extreme points in any two of the voltage time series signals comprises: Respectively obtain a maximum value set of a first voltage timing signal and a second voltage timing signal, and obtain a time union of the maximum value sets of the first voltage timing signal and the second voltage timing signal; the first voltage timing signal and the second voltage timing signal are any two voltage timing signals; Acquire the moments and collect the voltage value differences in the first voltage timing signal and the second voltage timing signal at each moment; The voltage value differences corresponding to the moments are integrated and concentrated to obtain the amplitude linear displacement of the monitoring area.

4. A method for monitoring deformation of a dam in a hydraulic engineering project as claimed in claim 3, characterized in that: The step of fusing the moments and concentrating the voltage value differences corresponding to all moments to obtain the amplitude linear displacement of the monitoring area includes: Calculate the voltage value difference average value of the voltage value differences corresponding to the moment and all moments in the set to obtain the overall voltage difference between the first voltage timing signal and the second voltage timing signal; The average value of the overall voltage difference of all any two voltage time series signals is calculated and normalized to obtain the amplitude linear displacement of the monitoring area.

5. A method for monitoring deformation of a dam in a hydraulic engineering project as claimed in claim 2, characterized in that: The abnormality degree of the electrical data characteristic of the monitoring area is obtained according to the difference in the number of extreme value points in any two of the voltage time series signals and the phase difference in the frequency domain signal, including: Obtaining the number of maximum values ​​of a first voltage timing signal and a second voltage timing signal, and obtaining the difference in the number of maximum values ​​between the first voltage timing signal and the second voltage timing signal; the first voltage timing signal and the second voltage timing signal are any two voltage timing signals; Converting the first voltage timing signal and the second voltage timing signal into frequency domain signals respectively, and obtaining a phase difference between the frequency domain signals of the first voltage timing signal and the second voltage timing signal; The maximum value quantity difference and the phase difference are integrated to obtain the abnormal degree of the electrical data characteristics of the monitoring area.

6. A method for monitoring deformation of a dam in a hydraulic engineering project as claimed in claim 5, characterized in that: The fusing of the maximum value quantity difference and the phase difference to obtain the abnormality degree of the electrical data characteristic of the monitoring area includes: Calculating the product of the maximum value quantity difference and the phase difference between the first voltage timing signal and the second voltage timing signal to obtain the data sub-abnormality degree corresponding to the first voltage timing signal and the second voltage timing signal; The average value of the data sub-abnormality levels corresponding to any two voltage time series signals is calculated and normalized to obtain the abnormality level of the electrical data characteristics of the monitoring area.

7. A method for monitoring deformation of a dam in a hydraulic engineering project according to claim 1, characterized in that: The temperature anomaly value of the monitoring point is the isolated forest score value of the monitoring point; and the overall temperature anomaly degree is the average of the isolated forest score values ​​of all monitoring points.

8. A method for monitoring deformation of a dam in a hydraulic engineering project according to claim 1, characterized in that: The method of correcting the output of the optical fiber stress sensor during the process of converting the grating wavelength into an electrical signal according to the optical fiber stretching degree of the monitoring area and the overall temperature anomaly degree of the monitoring area includes: Obtaining a correction coefficient according to the degree of optical fiber stretching and the degree of overall temperature anomaly in the monitoring area; According to the correction coefficient and the original output amount in the process of converting the grating wavelength in the optical fiber stress sensor into an electrical signal, the corrected output amount in the process of converting the grating wavelength in the optical fiber stress sensor into an electrical signal is obtained.

9. A method for monitoring deformation of a dam in a hydraulic engineering project according to claim 1, characterized in that: The water conservancy project dam deformation monitoring method also includes: comparing the overall temperature abnormality with a preset temperature abnormality threshold; If the overall temperature abnormality is greater than the preset temperature abnormality threshold, a temperature interference alarm instruction is output.

10. A water conservancy project dam deformation monitoring system, characterized in that: include: Memory and processor; The memory is connected to the processor; The memory is used to store program instructions; The processor is used to implement the water conservancy project dam deformation monitoring method described in any one of claims 1 to 9 when the program instructions are executed.

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