Dam stability data monitoring and processing system and method

Abstract

The present invention discloses a dam stability data monitoring and processing system and method, which relates to the technical field of dam safety monitoring. The system comprises the following steps: first, respectively acquiring instrument and image data, and analyzing the corresponding displacement data acquired; then, establishing a projection relationship between displacement measuring points and surface identification points, constructing a displacement constraint matrix, and constructing a corresponding dam finite element model; finally, constructing a proportional value using stress and strain results output by the model, constructing an abnormal marking rule based on the proportional value, and marking and warning abnormal areas of the dam; such a design realizes that by establishing a projection relationship between displacement measuring points and surface identification points and constructing a displacement constraint matrix, which is applied to the finite element model as a displacement constraint condition, an accurate dam finite element model is constructed, and the stress and strain results output by the model are used to construct a proportional value and an abnormal marking rule, thereby effectively identifying abnormal areas in the dam structure.

Description

Technical Field

[0001] The present invention belongs to the technical field, and in particular relates to a dam stability data monitoring and processing system and method. Background Art

[0002] As an important water conservancy infrastructure, the stability of dams is of vital importance to ensuring the safety of life and property in downstream areas and the sustainable development of the economy and society.

[0003] However, although the existing dam stability monitoring methods have achieved stability monitoring to a certain extent, the collection of monitoring data often relies on regular manual inspections, which is not only inefficient, but also difficult to achieve real-time and continuous monitoring, and difficult to comprehensively process and analyze multi-source data. The data processing and analysis methods are relatively backward, mainly relying on manual experience and simple statistical analysis, making it difficult to conduct in-depth mining and comprehensive evaluation of a large amount of monitoring data. There is a lack of building a corresponding dam finite element model for analysis, and a lack of discovering potential safety hazards. For this reason, a dam stability data monitoring and processing system and method came into being, which can realize the dam stability system with automatic collection, intelligent processing and abnormal detection and early warning of dam stability data. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a dam stability data monitoring and processing system and method for solving the following technical problems:

[0005] Although existing dam stability monitoring methods have achieved stability monitoring to a certain extent, the collection of monitoring data often relies on regular manual inspections, which is not only inefficient but also difficult to achieve real-time and continuous monitoring. It is also difficult to comprehensively process and analyze multi-source data. The data processing and analysis methods are relatively backward, mainly relying on manual experience and simple statistical analysis. It is difficult to conduct in-depth mining and comprehensive evaluation of large amounts of monitoring data. There is a lack of construction of corresponding dam finite element models for analysis, and there is a lack of discovery of potential safety hazards.

[0006] To solve the above problems, the first aspect of the present invention provides a dam stability data monitoring and processing system, comprising the following modules:

[0007] Instrument data acquisition module: Various special instruments are installed in the internal and external environments of the dam to obtain corresponding data;

[0008] Image data acquisition module: Use a drone equipped with an infrared camera to take low-altitude photos and measurements of the dam and its surrounding environment to obtain image data;

[0009] Instrument and Image Data Analysis Module: This module pre-processes displacement meter data, sets CGC200 as the global standard, lays out markers, and decomposes displacement vector records. It then calibrates the drone image to identify the markers, extracts feature vectors, and uses the SIFT algorithm to match and determine displacement.

[0010] Dam Monitoring and Analysis Module: Extracts and interpolates displacement meter data within a time window, aligns them, establishes the projection relationship between displacement meter measurement points and surface marker points, and constructs a displacement constraint matrix, which is applied to the finite element model as a displacement constraint. By obtaining relevant dam data, loads and boundary conditions are determined, and a finite element model is constructed using professional software to analyze stress and strain results.

[0011] Abnormal marking construction module: Calculate the corresponding ratio value by analyzing the results of stress and strain, and construct abnormal marking rules based on the ratio value.

[0012] Furthermore, the instrument data acquisition module includes:

[0013] According to the monitoring requirements and structural characteristics of the dam, displacement meters, strain gauges, piezometers and thermometers are installed at key locations inside the dam body; float-type water level gauges and total stations are installed at key locations outside the dam body;

[0014] The data collection interval is set to collect data every half hour, and wireless communication is used to transmit data to the monitoring center. A local server is set up in the monitoring center, and the acquired data is written to the local server in real time through the Modbus / TCP protocol. The database is fully backed up to the local NAS at 1 am every day.

[0015] Furthermore, the image data acquisition module includes:

[0016] Conduct a comprehensive survey of the dam and its surroundings to determine the take-off and landing points for the drone. A grid-based flight path planning method is used to determine the drone's flight parameters, including altitude, speed, and heading, taking into account the dam's shape, size, and key monitoring areas.

[0017] The operator controls the drone to fly according to the planned flight route, monitors the drone's flight status and the infrared camera's imaging status in real time through the image transmission system, and photographs the area with surface marking points every half hour at a set time interval to obtain image data of the dam surface. After the flight, the image data stored in the camera's memory card is annotated, including the time, location, and shooting angle of the shot; the same storage and backup methods as in the instrument data acquisition module are used, and denoising and image enhancement processing are performed.

[0018] Furthermore, the instrument and image data analysis module includes:

[0019] Perform data cleaning and data conversion on the raw data collected by the displacement meter; set the dam design coordinate system CGC200 as the global standard, and set at least four permanent surface identification points on the dam surface;

[0020] Determine the relationship between each direction and the coordinate axis at each displacement meter monitoring point. Based on the vector decomposition principle, decompose the total displacement vector into the directions of each coordinate axis. Based on the decomposition principle and the determined coordinate system, calculate the magnitude and direction of the displacement components of each monitoring point in different directions. Create a data record table for each monitoring point, recording its displacement values in the x, y, and z directions and the corresponding timestamps.

[0021] The images taken by the drone are subjected to geometric and radiation correction. The image recognition algorithm is used to automatically identify the pre-set surface identification points in the corrected images. The feature extraction algorithm is used to extract the center coordinates, grayscale features and texture features of the surface identification points as the image feature vectors of the surface identification points. According to the feature vectors of the surface identification points in images of different time series, the SIFT-based matching algorithm is used to determine the position change of the surface identification points in the two images taken before and after, and calculate the displacement data of the dam surface.

[0022] Furthermore, the construction of the displacement constraint matrix, which is applied to the finite element model as a displacement constraint condition, includes the following steps:

[0023] Sampling time of drone , extract the displacement meter data within the time window from the displacement meter, and assume that the extracted displacement meter data is the three-dimensional coordinate point , where n is the number of data points, and the time point corresponding to the data is ;

[0024] Assume that the time point at which the infrared camera obtains the surface marker data is , use linear interpolation to get the time point Precise alignment of displacement gauge coordinates ;

[0025] For each surface identification point Psur (X, Y), assume that its corresponding actual three-dimensional coordinates are (x sur ,y sur , z sur ), establish displacement measurement points through perspective projection model The projection relationship to the surface identification point Psur (X, Y):

[0026] ;

[0027] in, is the focal length of the camera, Displacement measuring point The coordinates of is the coordinate of the surface marker point Psur;

[0028] For each mapping point pair , perform trend consistency test; for the mapping point pairs that pass the trend consistency test, calculate their internal distance and surface distance, determine the corresponding weights of the internal distance and surface distance according to the accuracy of the instrument and the infrared camera carried by the UAV, and add them to obtain the comprehensive displacement. The comprehensive displacement of all mapping point pairs that pass the trend consistency test is combined into a displacement constraint vector, and a displacement constraint matrix is constructed, which is applied to the finite element model as a displacement constraint condition.

[0029] Furthermore, the finite element model comprises the following steps:

[0030] Obtain the dam's design drawings, including dimensions, material properties, and structural layout; collect an address survey report for the dam's location; obtain information on the foundation soil type, bearing capacity, and groundwater level; and conduct relevant dam material property tests to determine the load conditions, displacement constraints, and boundary conditions to which the dam is subject, including hydrostatic pressure, sediment pressure, temperature changes, and seismic action.

[0031] Use professional finite element pre-processing software to build a 3D geometric model of the dam based on the design drawings. Select the element type based on the dam's structure and stress characteristics, adjust the mesh size and shape, and use an automatic mesh generation algorithm to mesh the geometric model.

[0032] Based on the actual constraints of the dam, symmetrical boundary and fixed support boundary conditions are set, load conditions and displacement constraints are applied to the model, material property test results are input into the model, mechanical properties are defined for each material, and the model is solved using finite element software to output stress and strain related results;

[0033] The stress distribution output by the finite element model is analyzed as well as the strain distribution. If all indicators are within the normal range, the dam structure is safe. Otherwise, the dam structure is abnormal and further analysis is conducted.

[0034] Furthermore, the analysis based on the stress distribution output by the finite element model includes the following steps:

[0035] Use professional finite element analysis software to solve the constructed finite element model and calculate the stress value of each node. Based on the mechanical properties of the dam material, dynamically adjust its allowable stress threshold. Compare the calculated stress value of each node with its allowable stress threshold, and determine whether the node has excessive stress based on the stress ratio value.

[0036] Stress ratio calculation formula:

[0037] ;

[0038] in, For the The stress ratio value of each node, For the The stress value of each node, For the The allowed gradient threshold corresponding to each node;

[0039] like , it means that there is stress over limit phenomenon at the node, otherwise, it means that there is no stress over limit phenomenon at the node;

[0040] Use graphical tools to draw the stress distribution diagram of the dam structure, intuitively display the stress conditions in each area, calculate the stress ratio value of each node, and mark it on the distribution diagram.

[0041] Furthermore, the analysis of the strain distribution includes the following steps:

[0042] Extract the strain value of each node from the finite element model, determine the maximum allowable strain value based on the mechanical properties of the dam material, and compare the strain value of each node with the maximum allowable strain value of the material to determine whether the node has exceeded the strain limit;

[0043] Use a graphical tool to read the strain value output by the finite element model and draw a strain distribution diagram of the dam structure. Mark the strain value and position of each area in the diagram. Calculate the ratio of the strain value of each node to the maximum strain value allowed by the material and mark the ratio value on the strain distribution diagram. Use the same calculation method as the stress ratio value to obtain the first Strain proportional value of each node ,like , it means that there is an over-strain phenomenon at the node; otherwise, it means that there is no over-strain phenomenon at the node.

[0044] Furthermore, the abnormality marking construction module includes:

[0045] Construct anomaly marking rules, including single-indicator and double-indicator over-limit;

[0046] Set single indicator limit: If , the stress at the corresponding node exceeds the limit, triggering a yellow warning. , the corresponding node has an over-limit strain phenomenon, triggering an orange warning;

[0047] Set double index over limit: If and , there are two over-limit phenomena at the corresponding node, triggering a red warning.

[0048] The present invention also provides a dam stability data monitoring and processing method, comprising the following steps:

[0049] S1: Install various specialized instruments in the internal and external environments of the dam to obtain corresponding data;

[0050] S2: Use a drone equipped with an infrared camera to take low-altitude photos and measurements of the dam and its surroundings to obtain image data;

[0051] S3: Preprocess the displacement meter data, set CGC200 as the global standard, lay out markers and decompose the displacement vector records, identify the markers after correcting the UAV image, extract the feature vectors, and use the SIFT algorithm to match and determine the displacement;

[0052] S4: Extract the displacement meter data within the time window, interpolate and align them, establish the projection relationship between the displacement meter measurement points and the surface identification points, and construct a displacement constraint matrix. This matrix is applied to the finite element model as a displacement constraint condition. By obtaining relevant dam data, the load and boundary conditions are determined, and a finite element model is constructed using professional software to analyze the stress and strain results.

[0053] S5: Calculate the corresponding ratio value by analyzing the results of stress and strain, and construct an abnormal marking rule based on the ratio value.

[0054] Beneficial effects of the present invention:

[0055] The present invention acquires instrument data and image data through the instrument data acquisition module and the image data acquisition module respectively, processes and analyzes them, realizes the integration and comprehensive analysis of multi-source data, helps to more comprehensively understand the deformation of the dam, and improves the accuracy and reliability of monitoring;

[0056] The present invention establishes the projection relationship between displacement measurement points and surface identification points through the dam monitoring and analysis module, and constructs a displacement constraint matrix. This is applied to the finite element model as a displacement constraint condition, thereby constructing an accurate dam finite element model. This model can simulate the stress and strain state of the dam under actual working conditions and provide a powerful tool for stability assessment.

[0057] The present invention constructs proportional values through the stress-strain results output by the finite element model, and constructs abnormal marking rules based on the proportional values. It can effectively identify abnormal areas in the dam structure. Through timely marking and early warning, repair measures can be quickly taken to prevent potential accidents and ensure the safe and stable operation of the dam. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1It is a schematic diagram of the module flow of the present invention;

[0059] Figure 2 Schematic diagram of the method of the present invention. DETAILED DESCRIPTION

[0060] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0061] See also Figure 1 As shown, the present invention is a dam stability data monitoring and processing system, which includes the following modules:

[0062] Instrument data acquisition module: Various special instruments are installed in the internal and external environments of the dam to obtain corresponding data;

[0063] Image data acquisition module: Use a drone equipped with an infrared camera to take low-altitude photos and measurements of the dam and its surrounding environment to obtain image data;

[0064] Instrument and Image Data Analysis Module: This module pre-processes displacement meter data, sets CGC200 as the global standard, lays out markers, and decomposes displacement vector records. It then calibrates the drone image to identify the markers, extracts feature vectors, and uses the SIFT algorithm to match and determine displacement.

[0065] Dam Monitoring and Analysis Module: Extracts and interpolates displacement meter data within a time window, aligns them, establishes the projection relationship between displacement meter measurement points and surface marker points, and constructs a displacement constraint matrix, which is applied to the finite element model as a displacement constraint. By obtaining relevant dam data, loads and boundary conditions are determined, and a finite element model is constructed using professional software to analyze stress and strain results.

[0066] Abnormal marking construction module: Calculate the corresponding ratio value by analyzing the results of stress and strain, and construct abnormal marking rules based on the ratio value.

[0067] Specifically, according to the monitoring requirements and structural characteristics of the dam, determine the key locations inside the dam where displacement meters, strain gauges, piezometers and thermometers need to be installed, determine the key locations outside the dam suitable for installing float-type water level gauges and total stations, set the data collection time interval to collect data every half hour according to the monitoring requirements, and use full backup to back up the data; use professional flight planning software or tools to input the parameters and grid division information of the dam, generate the flight route of the drone, and take pictures of the areas with surface marking points at the set time intervals. After the flight, mark the image data stored in the camera memory card; set the dam design coordinate system CGC200 as the global standard coordinate system to obtain the data of each displacement meter. The location information of the monitoring point is used to automatically identify the pre-set surface identification points using an image recognition algorithm: standard template images of the surface identification points can be stored in advance, and then template matching is performed in the images taken by the drone to find the most similar area as the location of the surface identification point; based on the coordinates of the displacement meter measuring point and the surface identification point, the internal distance and surface distance of each mapping point pair are calculated respectively, and the weight coefficients of the two are determined according to the accuracy indicators of the displacement meter and the drone; the design drawings, geological survey data, load conditions, boundary conditions and displacement constraints of the dam are determined to construct a finite element model; the stress and strain results output by the finite element model are analyzed to construct stress ratio values and strain ratio values; an abnormal warning signal is constructed based on the two ratio values.

[0068] In one embodiment of the present invention, the instrument data acquisition module includes:

[0069] According to the monitoring requirements and structural characteristics of the dam, displacement meters, strain gauges, piezometers and thermometers are installed at key locations inside the dam body; float-type water level gauges and total stations are installed at key locations outside the dam body;

[0070] The data collection interval is set to collect data every half hour, and wireless communication is used to transmit data to the monitoring center. A local server is set up in the monitoring center, and the acquired data is written to the local server in real time through the Modbus / TCP protocol. The database is fully backed up to the local NAS at 1 am every day.

[0071] Specifically, according to the monitoring requirements and structural characteristics of the dam, determine the key locations inside the dam where displacement meters, strain gauges, piezometers and thermometers need to be installed, and determine the key locations outside the dam suitable for installing float-type water level gauges and total stations, which are usually at the upstream and downstream water level observation points of the dam and the locations where the deformation of the dam can be fully monitored; after all monitoring equipment is installed and debugged, set the data collection time interval to collect data every half an hour according to the monitoring requirements, configure wireless communication modules for each monitoring device to ensure that it can transmit the collected data to the monitoring center via wireless means, select the appropriate wireless communication protocol and frequency band according to the type of equipment and communication requirements, and build a local server in the monitoring center, such as Windows Server operating system and MySQL database management system, etc., install software or services that support the Modbus / TCP protocol on the local server. The server side writes the acquired data to the local server database in real time according to the pre-configured Modbus / TCP protocol. Set 1:00 a.m. every day as the time for full database backup. Use the backup function provided by the database management system or third-party backup software to create a backup task. In the backup task, set the backup source to the database file on the local server and the backup target to the local NAS (Network Attached Storage) device. Specify the backup method as full backup, that is, backing up all data in the entire database each time.

[0072] In one embodiment of the present invention, the image data acquisition module includes:

[0073] Conduct a comprehensive survey of the dam and its surroundings to determine the take-off and landing points for the drone. A grid-based flight path planning method is used to determine the drone's flight parameters, including altitude, speed, and heading, taking into account the dam's shape, size, and key monitoring areas.

[0074] The operator controls the drone to fly according to the planned flight route, monitors the drone's flight status and the infrared camera's imaging status in real time through the image transmission system, and photographs the area with surface marking points every half hour at a set time interval to obtain image data of the dam surface. After the flight, the image data stored in the camera's memory card is annotated, including the time, location, and shooting angle of the shot; the same storage and backup methods as in the instrument data acquisition module are used, and denoising and image enhancement processing are performed.

[0075] Specifically, organize professionals to conduct a comprehensive survey of the dam and its surrounding environment to understand the terrain, obstacle distribution, electromagnetic environment, etc., mark the locations suitable for drone take-off and landing, and select several ideal take-off and landing points based on the survey results, and record their geographical coordinates and related features. Test the selected take-off and landing points to ensure that the drone can take off and land safely; obtain detailed design drawings or measured data of the dam, including geometric parameters such as the length, width, and height of the dam, analyze the structure of the dam and key monitoring parts, such as the dam body, slope protection, spillway, etc., and divide the dam surface into several grid areas according to the shape and size of the dam to ensure that each area can be covered by the drone According to the flight performance of the UAV and the viewing angle of the camera, the size of the grid and the spacing of the flight route are determined. Professional flight planning software or tools are used to input the parameters of the dam and the grid division information to generate the flight route of the UAV. According to the flight route and the performance characteristics of the UAV, the flight parameters such as flight altitude, speed and heading are determined. During the flight, the flight status of the UAV is monitored in real time through the image transmission system, including position, altitude, speed and other information. At the same time, the imaging of the infrared camera is monitored. At the set time interval, the area with surface identification points is photographed. After the flight, the image data stored in the camera memory card is annotated.

[0076] In one embodiment of the present invention, the instrument and image data analysis module include:

[0077] Perform data cleaning and data conversion on the raw data collected by the displacement meter; set the dam design coordinate system CGC200 as the global standard, and set at least four permanent surface identification points on the dam surface;

[0078] Determine the relationship between each direction and the coordinate axis at each displacement meter monitoring point. Based on the vector decomposition principle, decompose the total displacement vector into the directions of each coordinate axis. Based on the decomposition principle and the determined coordinate system, calculate the magnitude and direction of the displacement components of each monitoring point in different directions. Create a data record table for each monitoring point, recording its displacement values in the x, y, and z directions and the corresponding timestamps.

[0079] The images taken by the drone are subjected to geometric and radiation correction. The image recognition algorithm is used to automatically identify the pre-set surface identification points in the corrected images. The feature extraction algorithm is used to extract the center coordinates, grayscale features and texture features of the surface identification points as the image feature vectors of the surface identification points. According to the feature vectors of the surface identification points in images of different time series, the SIFT-based matching algorithm is used to determine the position change of the surface identification points in the two images taken before and after, and calculate the displacement data of the dam surface.

[0080] Specifically, the dam design coordinate system CGC200 is set as the global standard coordinate system, and the position information of each displacement meter monitoring point is obtained, including the specific position and spatial orientation on the dam surface. According to the structure of the dam and the arrangement of the monitoring points, the relationship between each direction and the coordinate axis at each monitoring point is determined. For example, for a horizontally arranged displacement meter, its measurement direction may be parallel to the x-direction or y-direction of the coordinate axis; for a vertically arranged displacement meter, the measurement direction is consistent with the z-axis direction; according to the vector decomposition principle, the total displacement vector is decomposed into the directions of each coordinate axis, and according to the determined coordinate relationship and decomposition principle, the displacement component of each monitoring point in different directions is calculated. For example, if the angle between the total displacement vector and the x-axis is θ and the displacement magnitude is D, then the displacement component in the x-direction is D×cosθ, and a vector is created for each monitoring point. A data record table is formed, and the table content includes timestamp, x-direction displacement value, y-direction displacement value, and z-direction displacement value; in the corrected image, image preprocessing operation is first performed to improve the accuracy of image recognition, and the pre-set surface identification points are automatically identified using the image recognition algorithm: the standard template image of the surface identification point can be stored in advance, and then template matching is performed in the image taken by the drone to find the most similar area as the position of the surface identification point; the feature extraction algorithm is used to extract the center coordinates, grayscale features and texture features of the surface identification point as the image feature vector of the surface identification point; the SIFT algorithm finds the corresponding surface identification points in different images by comparing the similarity of the feature vectors, and calculates the position offset between them, converts the position offset into an actual displacement value and determines the direction of the displacement.

[0081] In one embodiment of the present invention, constructing a displacement constraint matrix, which is applied to the finite element model as a displacement constraint condition, includes the following steps:

[0082] Sampling time of drone , extract the displacement meter data within the time window from the displacement meter, and assume that the extracted displacement meter data is the three-dimensional coordinate point , where n is the number of data points, and the time point corresponding to the data is ;

[0083] Assume that the time point at which the infrared camera obtains the surface marker data is , use linear interpolation to get the time point Precise alignment of displacement gauge coordinates ;

[0084] For each surface identification point Psur (X, Y), assume that its corresponding actual three-dimensional coordinates are (x sur ,y sur , z sur ), establish displacement measurement points through perspective projection model The projection relationship to the surface identification point Psur (X, Y):

[0085] ;

[0086] in, is the focal length of the camera, Displacement measuring point The coordinates of is the coordinate of the surface marker point Psur;

[0087] For each mapping point pair , perform trend consistency test; for the mapping point pairs that pass the trend consistency test, calculate their internal distance and surface distance, determine the corresponding weights of the internal distance and surface distance according to the accuracy of the instrument and the infrared camera carried by the UAV, and add them to obtain the comprehensive displacement. The comprehensive displacement of all mapping point pairs that pass the trend consistency test is combined into a displacement constraint vector, and a displacement constraint matrix is constructed, which is applied to the finite element model as a displacement constraint condition.

[0088] Specifically, for each mapping point pair ; Calculate the direction vector from the displacement measurement point to the surface identification point and the cosine value of the angle between the direction vector of all mapping point pairs and the z-axis direction vector, and compare the cosine value of the angle with the preset threshold. If the cosine value of the angle is greater than the preset threshold, the trend of the mapping point pair is consistent with the reference direction and passes the test; otherwise, it fails the test; wherein the preset threshold is set to μ−2σ, μ is the average of the cosine value of the angle measured multiple times, which can eliminate the deviation caused by measurement error to a certain extent; for the mapping point pairs that pass the trend consistency test, calculate their internal distance and surface distance, determine the weights corresponding to the internal distance and surface distance according to the accuracy of the instrument and the infrared camera carried by the drone, and add the weighted values to obtain the comprehensive displacement. The comprehensive displacement of all mapping point pairs that pass the trend consistency test is composed of a displacement constraint vector. According to the node degrees of freedom of the finite element model and the correspondence between the mapping point pairs and the nodes, a displacement constraint matrix is constructed. Each row of the matrix corresponds to a mapping point pair, and each column corresponds to the degree of freedom of a node. If there is a correspondence between the mapping point and the node, the element at that position is 1, otherwise it is 0; it is applied to the finite element model as a displacement constraint condition;

[0089] The internal distance, i.e. the displacement measuring point The distance to the surface marker point Psur in the actual three-dimensional space is obtained by:

[0090] ;

[0091] get is the internal distance of the point, and Psur and The three-dimensional coordinates of

[0092] The surface distance is the two-dimensional image distance from the projection point of the displacement measurement point on the image plane to the surface identification point;

[0093] The weights corresponding to the internal distance and the surface distance are determined according to the accuracy of the instrument and the infrared camera carried by the UAV, that is, the displacement meter accuracy and the camera positioning accuracy are unified in units and added to obtain the comprehensive accuracy, and the displacement meter accuracy and the camera positioning accuracy are divided by the comprehensive accuracy respectively to obtain the corresponding accuracy ratio value as its corresponding weight.

[0094] In one embodiment of the present invention, the finite element model comprises the following steps:

[0095] Obtain the dam's design drawings, including dimensions, material properties, and structural layout; collect an address survey report for the dam's location; obtain information on the foundation soil type, bearing capacity, and groundwater level; and conduct relevant dam material property tests to determine the load conditions, displacement constraints, and boundary conditions to which the dam is subject, including hydrostatic pressure, sediment pressure, temperature changes, and seismic action.

[0096] Use professional finite element pre-processing software to build a 3D geometric model of the dam based on the design drawings. Select the element type based on the dam's structure and stress characteristics, adjust the mesh size and shape, and use an automatic mesh generation algorithm to mesh the geometric model.

[0097] Based on the actual constraints of the dam, symmetrical boundary and fixed support boundary conditions are set, load conditions and displacement constraints are applied to the model, material property test results are input into the model, mechanical properties are defined for each material, and the model is solved using finite element software to output stress and strain related results;

[0098] The stress distribution output by the finite element model is analyzed as well as the strain distribution. If all indicators are within the normal range, the dam structure is safe. Otherwise, the dam structure is abnormal and further analysis is conducted.

[0099] Specifically, get in touch with the dam construction, design or management unit, obtain the dam design drawings through formal application, communication and coordination, conduct detailed verification of the obtained design drawings, apply for a geological survey report, sort out the contents of the report, collect representative material samples at different parts of the dam, for concrete materials, drill holes for sampling at different pouring locations; for soil and rock materials, select undisturbed soil or rock samples at different depths and locations of the dam body, and determine the material property test items that need to be carried out based on the material type and dam structural characteristics, such as the compressive strength and elastic modulus of concrete. The collected samples are sent to a professional material laboratory, and the material properties are tested according to standard test methods using appropriate instruments and equipment, and the test results are recorded. Based on the design shape, size, and water level of the dam, the principles of fluid mechanics are used to calculate the distribution of hydrostatic pressure on the dam. Considering factors such as the sediment characteristics and water flow velocity of the river where the dam is located, the thickness and range of sediment deposited upstream of the dam are estimated, and then the horizontal pressure exerted by the sediment on the dam is calculated. Historical meteorological data such as air temperature and water temperature in the area where the dam is located are collected. Using real-time monitoring data, the thermal stresses generated by temperature changes on the dam are determined. Based on the seismic activity and seismic fortification requirements of the dam's location, seismic hazard analysis methods are used to determine the parameters of potential earthquakes. The dam's design drawings are imported into professional finite element pre-processing software in an appropriate file format. The outlines and dimensions of the dam's various components are automatically identified based on the imported drawing information, and the geometric model is meshed using the software's automatic mesh generation algorithm. Symmetrical boundaries are set by specifying node degree-of-freedom constraints on symmetry planes. Fixed support boundary conditions are applied to the corresponding nodes based on the dam's actual support conditions. Previously calculated load conditions, such as hydrostatic pressure, sediment pressure, thermal stresses generated by temperature changes, and seismic effects, are appropriately input into the model. Determined displacement constraints are applied to designated nodes or regions of the model. Based on material property test results, the mechanical property parameters of each material are defined in the finite element model. An appropriate solver, such as a direct or iterative solver, is selected in the finite element software, and the solver settings are configured accordingly based on the scale and nature of the problem. The output result type and format are set before solving the problem. In one embodiment of the present invention, the analysis based on the stress distribution output by the finite element model includes the following steps:

[0100] Use professional finite element analysis software to solve the constructed finite element model and calculate the stress value of each node. Based on the mechanical properties of the dam material, dynamically adjust its allowable stress threshold. Compare the calculated stress value of each node with its allowable stress threshold, and determine whether the node has excessive stress based on the stress ratio value.

[0101] Stress ratio calculation formula:

[0102] ;

[0103] in, For the The stress ratio value of each node, For the The stress value of each node, For the The allowed gradient threshold corresponding to each node;

[0104] like , it means that there is stress over limit phenomenon at the node, otherwise, it means that there is no stress over limit phenomenon at the node;

[0105] Use graphical tools to draw the stress distribution diagram of the dam structure, intuitively display the stress conditions in each area, calculate the stress ratio value of each node, and mark it on the distribution diagram.

[0106] Specifically, the mechanical properties of different materials, such as concrete and soil and rock, are searched in dam design documents or relevant specifications. These parameters include elastic modulus, Poisson's ratio, compressive strength, and tensile strength. These parameters form the basis for determining the allowable stress threshold. The actual operating conditions of the dam, such as water level fluctuations, temperature changes, and seismic effects, are then considered. Appropriate adjustment coefficients are then determined for different operating conditions and different parts of the dam. For example, when the water level is high, the allowable stress threshold of the underwater dam material may need to be appropriately lowered due to the buoyancy and pressure of the water. Using the software's secondary development capabilities, the allowable stress threshold for each node under different operating conditions can be calculated based on the obtained material mechanical properties and adjustment coefficients. Using data processing software, the extracted node stress values are divided by the corresponding allowable stress threshold to obtain the stress ratio value for each node. This determines whether any node exhibits excessive stress. In the post-processing module of the finite element analysis software, select "Plot Results" or a similar function and choose an appropriate plotting method to draw a stress distribution diagram of the dam structure. The stress ratio value for each node can be annotated on the stress distribution diagram using the software's annotation function or graphic editing tools.

[0107] The example table of dam stress exceeding limit judgment is shown in Table 1:

[0108] Table 1.

[0109]

[0110] In one embodiment of the present invention, the analyzing of the strain distribution comprises the following steps:

[0111] Extract the strain value of each node from the finite element model, determine the maximum allowable strain value based on the mechanical properties of the dam material, and compare the strain value of each node with the maximum allowable strain value of the material to determine whether the node has exceeded the strain limit;

[0112] Use a graphical tool to read the strain value output by the finite element model and draw a strain distribution diagram of the dam structure. Mark the strain value and position of each area in the diagram. Calculate the ratio of the strain value of each node to the maximum strain value allowed by the material and mark the ratio value on the strain distribution diagram. Use the same calculation method as the stress ratio value to obtain the first Strain proportional value of each node ,like , it means that there is an over-strain phenomenon at the node; otherwise, it means that there is no over-strain phenomenon at the node.

[0113] Specifically, open the finite element analysis software, and after completing the model solution, enter the post-processing module of the software, directly click on a single node on the model with the mouse, or use the node selection tool provided by the software to select the node, and output the strain value of the selected node to a text file, a table file or a specific data structure within the software for subsequent operations; consult the mechanical properties data of various materials used in dam design and construction, and calculate the maximum allowable strain value of each material under different working conditions based on the mechanical properties parameters of the materials, and organize the calculated maximum allowable strain value in a manner that aligns with the node table to form a format corresponding to the node strain value data; compare the extracted node strain value data with the organized maximum allowable strain value data one by one, calculate the strain ratio value of each node, and determine whether the node has strain exceeding the limit based on the strain ratio value; in the graphical tool, draw a strain distribution diagram of the dam structure based on the imported node strain value data, and mark the strain ratio value and position information of each node on the strain distribution diagram.

[0114] The example table of dam strain exceeding limit judgment is shown in Table 2:

[0115] Table 2.

[0116]

[0117] In one embodiment of the present invention, the abnormality marking construction module includes:

[0118] Construct anomaly marking rules, including single-indicator and double-indicator over-limit;

[0119] Set single indicator limit: If , the stress at the corresponding node exceeds the limit, triggering a yellow warning. , the corresponding node has an over-limit strain phenomenon, triggering an orange warning;

[0120] Set double index over limit: If and , there are two over-limit phenomena at the corresponding node, triggering a red warning.

[0121] Specifically, defining single-index over-limit rules includes clarifying the evaluation criteria for stress and strain. For stress, when the stress ratio value of a node is greater than 1, it is considered a stress over-limit; for strain, when the strain ratio value of a node is greater than 1, it is considered a strain over-limit. The corresponding relationship between warning colors and over-limit types is determined. When stress exceeds the limit, a yellow warning is triggered; when strain exceeds the limit, an orange warning is triggered. Defining dual-index over-limit rules includes stipulating that when both the stress ratio and strain ratio values of the same node are greater than 1, it is determined that the node has two over-limit phenomena, namely, a dual-index over-limit phenomenon. When dual-index over-limit is determined, a red warning is triggered to highlight this more serious abnormality.

[0122] See also Figure 2 As shown, the present invention is a dam stability data monitoring and processing method, comprising the following steps:

[0123] S1: Install various specialized instruments in the internal and external environments of the dam to obtain corresponding data;

[0124] S2: Use a drone equipped with an infrared camera to take low-altitude photos and measurements of the dam and its surroundings to obtain image data;

[0125] S3: Preprocess the displacement meter data, set CGC200 as the global standard, lay out markers and decompose the displacement vector records, identify the markers after correcting the UAV image, extract the feature vectors, and use the SIFT algorithm to match and determine the displacement;

[0126] S4: Extract the displacement meter data within the time window, interpolate and align them, establish the projection relationship between the displacement meter measurement points and the surface identification points, and construct a displacement constraint matrix. This matrix is applied to the finite element model as a displacement constraint condition. By obtaining relevant dam data, the load and boundary conditions are determined, and a finite element model is constructed using professional software to analyze the stress and strain results.

[0127] S5: Calculate the corresponding ratio value by analyzing the results of stress and strain, and construct an abnormal marking rule based on the ratio value.

[0128] The above embodiments are only used to illustrate the technical method of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A dam stability data monitoring and processing system, characterized in that: Includes the following modules: Instrument data acquisition module: Various special instruments are installed in the internal and external environments of the dam to obtain corresponding data; Image data acquisition module: Use a drone equipped with an infrared camera to take low-altitude photos and measurements of the dam and its surrounding environment to obtain image data; Instrument and Image Data Analysis Module: This module pre-processes displacement meter data, sets CGC200 as the global standard, lays out markers, and decomposes displacement vector records. It then calibrates the drone image to identify the markers, extracts feature vectors, and uses the SIFT algorithm to match and determine displacement. Dam Monitoring and Analysis Module: Extracts and interpolates displacement meter data within a time window, aligns them, establishes the projection relationship between displacement meter measurement points and surface marker points, and constructs a displacement constraint matrix, which is applied to the finite element model as a displacement constraint. By obtaining relevant dam data, loads and boundary conditions are determined, and a finite element model is constructed using professional software to analyze stress and strain results. Abnormal marking construction module: calculates the corresponding ratio value by analyzing the results of stress and strain, and constructs abnormal marking rules based on the ratio value; The construction of the displacement constraint matrix, which is applied to the finite element model as a displacement constraint condition, includes the following steps: Sampling time of drone , extract the displacement meter data within the time window from the displacement meter, and assume that the extracted displacement meter data is the three-dimensional coordinate point , where n is the number of data points, and the time point corresponding to the data is ; Assume that the time point at which the infrared camera obtains the surface marker data is , use linear interpolation to get the time point Precise alignment of displacement gauge coordinates ; For each surface identification point Psur (X, Y), assume that its corresponding actual three-dimensional coordinates are (x sur ,y sur , z sur ), establish displacement measurement points through perspective projection model The projection relationship to the surface identification point Psur (X, Y): ; in, is the focal length of the camera, Displacement measuring point The coordinates of is the coordinate of the surface marker point Psur; For each mapping point pair , perform trend consistency test; for the mapping point pairs that pass the trend consistency test, calculate their internal distance and surface distance, determine the corresponding weights of the internal distance and surface distance according to the accuracy of the instrument and the infrared camera carried by the UAV, and add them to obtain the comprehensive displacement. The comprehensive displacement of all mapping point pairs that pass the trend consistency test is combined into a displacement constraint vector, and a displacement constraint matrix is constructed, which is applied to the finite element model as a displacement constraint condition.

2. A dam stability data monitoring and processing system according to claim 1, characterized in that: The instrument data acquisition module includes: According to the monitoring requirements and structural characteristics of the dam, displacement meters, strain gauges, piezometers and thermometers are installed at key locations inside the dam body; float-type water level gauges and total stations are installed at key locations outside the dam body; The data collection interval is set to collect data every half hour, and wireless communication is used to transmit data to the monitoring center. A local server is set up in the monitoring center, and the acquired data is written to the local server in real time through the Modbus / TCP protocol. The database is fully backed up to the local NAS at 1 am every day.

3. A dam stability data monitoring and processing system according to claim 1, characterized in that: The image data acquisition module includes: Conduct a comprehensive survey of the dam and its surroundings to determine the take-off and landing points for the drone. A grid-based flight path planning method is used to determine the drone's flight parameters, including altitude, speed, and heading, taking into account the dam's shape, size, and key monitoring areas. The operator controls the drone to fly according to the planned flight route, monitors the drone's flight status and the infrared camera's imaging status in real time through the image transmission system, and photographs the area with surface marking points every half hour at a set time interval to obtain image data of the dam surface. After the flight, the image data stored in the camera's memory card is annotated, including the time, location, and shooting angle of the shot; the same storage and backup methods as in the instrument data acquisition module are used, and denoising and image enhancement processing are performed.

4. A dam stability data monitoring and processing system according to claim 1, characterized in that: The instrument and image data analysis module include: Perform data cleaning and data conversion on the raw data collected by the displacement meter; set the dam design coordinate system CGC200 as the global standard, and set at least four permanent surface identification points on the dam surface; Determine the relationship between each direction and the coordinate axis at each displacement meter monitoring point. Based on the vector decomposition principle, decompose the total displacement vector into the directions of each coordinate axis. Based on the decomposition principle and the determined coordinate system, calculate the magnitude and direction of the displacement components of each monitoring point in different directions. Create a data record table for each monitoring point, recording its displacement values in the x, y, and z directions and the corresponding timestamps. The images taken by the drone are subjected to geometric and radiation correction. The image recognition algorithm is used to automatically identify the pre-set surface identification points in the corrected images. The feature extraction algorithm is used to extract the center coordinates, grayscale features and texture features of the surface identification points as the image feature vectors of the surface identification points. According to the feature vectors of the surface identification points in images of different time series, the SIFT-based matching algorithm is used to determine the position change of the surface identification points in the two images taken before and after, and calculate the displacement data of the dam surface.

5. A dam stability data monitoring and processing system according to claim 1, characterized in that: The finite element model comprises the following steps: Obtain the dam's design drawings, including dimensions, material properties, and structural layout; collect an address survey report for the dam's location; obtain information on the foundation soil type, bearing capacity, and groundwater level; and conduct relevant dam material property tests to determine the load conditions, displacement constraints, and boundary conditions to which the dam is subject, including hydrostatic pressure, sediment pressure, temperature changes, and seismic action. Use professional finite element pre-processing software to build a 3D geometric model of the dam based on the design drawings. Select the element type based on the dam's structure and stress characteristics, adjust the mesh size and shape, and use an automatic mesh generation algorithm to mesh the geometric model. Based on the actual constraints of the dam, symmetrical boundary and fixed support boundary conditions are set, load conditions and displacement constraints are applied to the model, material property test results are input into the model, mechanical properties are defined for each material, and the model is solved using finite element software to output stress and strain related results; The stress distribution output by the finite element model is analyzed as well as the strain distribution. If all indicators are within the normal range, the dam structure is safe. Otherwise, the dam structure is abnormal and further analysis is conducted.

6. A dam stability data monitoring and processing system according to claim 5, characterized in that: The analysis based on the stress distribution output by the finite element model includes the following steps: Use professional finite element analysis software to solve the constructed finite element model and calculate the stress value of each node. Based on the mechanical properties of the dam material, dynamically adjust its allowable stress threshold. Compare the calculated stress value of each node with its allowable stress threshold, and determine whether the node has excessive stress based on the stress ratio value. Stress ratio calculation formula: ； in, For the The stress ratio value of each node, For the The stress value of each node, For the The allowed gradient threshold corresponding to each node; like >1, it means that there is stress over limit phenomenon at the node, otherwise it means that there is no stress over limit phenomenon at the node; Use graphical tools to draw the stress distribution diagram of the dam structure, intuitively display the stress conditions in each area, calculate the stress ratio value of each node, and mark it on the distribution diagram.

7. A dam stability data monitoring and processing system according to claim 5, characterized in that: The analysis of the strain distribution comprises the following steps: Extract the strain value of each node from the finite element model, determine the maximum allowable strain value based on the mechanical properties of the dam material, compare the strain value of each node with the maximum allowable strain value of the material, and determine whether the node has exceeded the strain limit; Use a graphical tool to read the strain value output by the finite element model and draw a strain distribution diagram of the dam structure. Mark the strain value and position of each area in the diagram. Calculate the ratio of the strain value of each node to the maximum strain value allowed by the material and mark the ratio value on the strain distribution diagram. Use the same calculation method as the stress ratio value to obtain the first Strain proportional value of each node ,like If it is greater than 1, it means that the strain at the node exceeds the limit; otherwise, it means that the strain at the node does not exceed the limit.

8. A dam stability data monitoring and processing system according to claim 1, characterized in that: The abnormality marking construction module includes: Construct anomaly marking rules, including single-indicator and double-indicator over-limit; Set single indicator limit: If >1, the stress at the corresponding node exceeds the limit, triggering a yellow warning. >1, the strain at the corresponding node exceeds the limit, triggering an orange warning; Set double index over limit: If >1 and >1, there are two over-limit phenomena at the corresponding node, triggering a red warning.

9. A dam stability data monitoring and processing method, using a dam stability data monitoring and processing system according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Install various specialized instruments in the internal and external environments of the dam to obtain corresponding data; S2: Use a drone equipped with an infrared camera to take low-altitude photos and measurements of the dam and its surroundings to obtain image data; S3: Preprocess the displacement meter data, set CGC200 as the global standard, lay out markers and decompose the displacement vector records, identify the markers after correcting the UAV image, extract the feature vectors, and use the SIFT algorithm to match and determine the displacement; S4: Extract the displacement meter data within the time window, interpolate and align them, establish the projection relationship between the displacement meter measurement points and the surface identification points, and construct a displacement constraint matrix. This matrix is applied to the finite element model as a displacement constraint condition. By obtaining relevant dam data, the load and boundary conditions are determined, and a finite element model is constructed using professional software to analyze the stress and strain results. S5: Calculate the corresponding ratio value by analyzing the results of stress and strain, and construct an abnormal marking rule based on the ratio value.

Images