scholarly journals Spatial Data Analysis for Deformation Monitoring of Bridge Structures

2020 ◽  
Vol 10 (23) ◽  
pp. 8731
Author(s):  
Ján Erdélyi ◽  
Alojz Kopáčik ◽  
Peter Kyrinovič
Keyword(s):  
Spatial Data ◽  
Laser Scanning ◽  
Deformation Monitoring ◽  
Radar Interferometry ◽  
Spatial Data Analysis ◽  
Deformation Analysis ◽  
Measuring Instruments ◽  
Engineering Structures ◽  
Essential Information ◽  
Bridge Structures

Weather conditions and different operational loads often cause changes in essential parts of engineering structures, and this affects the static and dynamic behavior and reliability of these structures. Therefore, geodetic monitoring is an integral part of the diagnosis of engineering structures and provides essential information about the current state (condition) of the structure. The development of measuring instruments enables deformation analyses of engineering structures using non-conventional surveying methods. Nowadays, one of the most effective techniques for spatial data collection is terrestrial laser scanning (TLS). TLS is frequently used for data acquisition in cases where three-dimensional (3D) data with high resolution is needed. Using suitable data processing, TLS can be used for static deformation analysis of the structure being monitored. For dynamic deformation measurements (structural health monitoring) of bridge structures, ground-based radar interferometry and accelerometers are often used for vibration mode determination using spectral analysis of frequencies. This paper describes experimental deformation monitoring of structures performed using TLS and ground-based radar interferometry. The procedure of measurement, the analysis of the acquired spatial data, and the results of deformation monitoring are explained and described.

scholarly journals Automated point clouds processing for deformation monitoring

2015 ◽  
Vol 14 (2) ◽  
pp. 47-54
Author(s):  
Ján Erdélyi
Keyword(s):  
Spatial Data ◽  
Laser Scanning ◽  
Operation Mode ◽  
Weather Conditions ◽  
Point Clouds ◽  
Deformation Monitoring ◽  
Engineering Structures ◽  
Measured Object ◽  
Dynamic Function ◽  
Accuracy Of Results

<p>The weather conditions and the operation load are causing changes in the spatial position and in the shape of engineering constructions, which affects their static and dynamic function and reliability. Because these facts, geodetic measurements are integral parts of engineering structures diagnosis.</p><p>The advantage of terrestrial laser scanning (TLS) over conventional surveying methods is the efficiency of spatial data acquisition. TLS allows contactless determining the spatial coordinates of points lying on the surface on the measured object. The scan rate of current scanners (up to 1 million of points/s) allows significant reduction of time, necessary for the measurement; respectively increase the quantity of obtained information about the measured object. To increase the accuracy of results, chosen parts of the monitored construction can be approximated by single geometric entities using regression. In this case the position of measured point is calculated from tens or hundreds of scanned points.</p><p>This paper presents the possibility of deformation monitoring of engineering structures using the technology of TLS. For automated data processing was developed an application based on Matlab®, Displacement_TLS. The operation mode, the basic parts of this application and the calculation of displacements are described.</p>

scholarly journals Spatial data analysis for laser scanning based shape error inspection

2021 ◽  
Author(s):  
Haibin Jia
Keyword(s):  
Fourier Transform ◽  
Spatial Data ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Industrial Applications ◽  
Spatial Data Analysis ◽  
Inspection System ◽  
Shape Error ◽  
Shape Errors ◽  
Weld Inspection

Laser scanning, a widely used technology, has been highly developed and adopted in various industrial applications. The methodologies used for scanner date processing are mostly point based. In this thesis, a new approach is presented to analyze spatial data obtained from a 3-D laser scanner for shape error inspection. Different from traditional methodologies, the method proposed in this research is frequency based. The method utilizes the Fourier transform to decompose a 2-D curve or 3-D shape into its spatial components by applying two 1-D FFT (Fast Fourier Transform) on 2-D curves or two 2-D FFT on 3-D shapes. The spatial components including frequency, amplitude, and phase are defined as shape characteristics to represent the shape under inspection. By relating spatial components with GD&T (Geometric Dimensioning and Tolerancing) standards using proper analysis techniques, such as frequency spectrum and cross correlation, shape errors can be detected and characterized. One of the applications of this method is automated inspection. In this research, the spatial data method is applied to MIG (Metal Inert Gas) weld inspection. Experiments are carried out to analyze the 2-D curve of a projection weld data, and the 3-D scanning data directly. A MIG weld inspection system is also developed for production use.

scholarly journals Big LIDAR Data in Digital Earth: Ways Out of Dead End

2020 ◽  
pp. paper46-1-paper46-10
Author(s):  
Ilya Rylskiy
Keyword(s):  
Data Storage ◽  
Spatial Data ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Alternative Methods ◽  
Measuring Instruments ◽  
Lidar Data ◽  
Data Sets ◽  
Spatial Data Sets ◽  
Limited Precision

During past 25 years, laser scanning has evolved from an experimental method into a fully autonomous family of Earth remote sensing methods. Now this group of methods provides the most accurate and detailed spatial data sets, while the cost of data is constantly falling, the number of measuring instruments (laser scanners) is constantly growing. The volumes of data that will be obtained during the surveys in the coming decades will allow the creation of the first sub-global coverage of the planet. However, the flip side of high accuracy and detail is the need to store fantastically large volumes of three-dimensional data without loss of accuracy. At the same time, the ability to work with the specified data in both 2D and 3D mode should be improved. Standard storage methods (file method, geodatabases, archiving, etc) solve the problem only partially. At the same time, there are some other alternative methods that can remove current restrictions and lead to the emergence of more flexible and functional spatial data infrastructures. One of the most flexible and promising ways of laser data storage and processing are quadtree and octree-based approaches. Of course, these approaches are more complicated than typical file data structures, that are commonly used for LIDAR data storage, but they allow users to solve some typical negative features of point datasets (processing speed, non-topological spatial structure, limited precision, etc.).

scholarly journals TLS-Based Feature Extraction and 3D Modeling for Arch Structures

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xiangyang Xu ◽  
Xin Zhao ◽  
Hao Yang ◽  
Ingo Neumann
Keyword(s):  
3D Modeling ◽  
Laser Scanning ◽  
High Efficiency ◽  
Data Extraction ◽  
Point Clouds ◽  
Deformation Monitoring ◽  
Deformation Analysis ◽  
Unknown Parameters ◽  
Automatic Data ◽  
B Spline

Terrestrial laser scanning (TLS) technology is one of the most efficient and accurate tools for 3D measurement which can reveal surface-based characteristics of objects with the aid of computer vision and programming. Thus, it plays an increasingly important role in deformation monitoring and analysis. Automatic data extraction and high efficiency and accuracy modeling from scattered point clouds are challenging issues during the TLS data processing. This paper presents a data extraction method considering the partial and statistical distribution of the point clouds scanned, called the window-neighborhood method. Based on the point clouds extracted, 3D modeling of the boundary of an arched structure was carried out. The ideal modeling strategy should be fast, accurate, and less complex regarding its application to large amounts of data. The paper discusses the accuracy of fittings in four cases between whole curve, segmentation, polynomial, and B-spline. A similar number of parameters was set for polynomial and B-spline because the number of unknown parameters is essential for the accuracy of the fittings. The uncertainties of the scanned raw point clouds and the modeling are discussed. This process is considered a prerequisite step for 3D deformation analysis with TLS.

scholarly journals Surface and New Building Deformation Analysis of Deep Well Strip Mining

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Yuanzhong Luan ◽  
Yue Dong ◽  
Yanhe Ma ◽  
Liyuan Weng
Keyword(s):  
Surface Deformation ◽  
Simulation Method ◽  
Deformation Monitoring ◽  
Deformation Analysis ◽  
Measuring Instruments ◽  
Strip Mining ◽  
Deep Well ◽  
Mining Depth ◽  
Mining Width ◽  
New Buildings

Aiming at the problem of surface movement and long-term stability of a work plane of deep well strip mining in Shandong Province, an observation station is set up on the surface of strip mining, and the surface deformation value during strip mining is measured with advanced measuring instruments; on the stable surface of the old mining area, the surface deformation monitoring work is also carried out for new buildings. In addition, the FLAC3D simulation method is used to determine the subsidence factor of different mining depth, mining width, mining length, and mining thickness, and the mathematical model between the subsidence factor and mining depth, mining width, mining length, and mining thickness is established. After the surface of the old goaf is basically stable after strip mining, the high-rise buildings are built. By changing the size of the new buildings and the amount of the load imposed on the surface, the surface deformation is simulated and calculated, and the relationship between the different load positions, load sizes, loading building sizes, and the surface activated deformation is obtained. The measured value of the surface deformation confirms that the load of the new buildings can induce the activation of the old goaf and make the surface generate secondary deformation, but the activated deformation makes the new building within the range of 1, so the new building is safe.

scholarly journals ANALYSIS OF METHODS AND MEANS OF CONTROL OF MAIN PIPELINES’ PROTECTIVE STRUCTURES

2020 ◽  
Vol 25 (4) ◽  
pp. 77-84
Author(s):  
Valeriya V. Dedkova ◽  
◽  
Alexander V. Komissarov ◽  
Keyword(s):  
Remote Sensing ◽  
Laser Scanning ◽  
Radar Interferometry ◽  
Monitoring Methods ◽  
Engineering Structures ◽  
Imaging Radar ◽  
Main Pipelines ◽  
Earth Structures ◽  
The Russian Federation ◽  
Protective Structures

The purpose of research is to justify methods and means of remote sensing for monitoring of technical state of various types of main pipelines’ protective structures. An analysis of accidents at main pipelines based on the data of the Federal Service for Ecological, Technological and Nuclear Supervision, as well as the Ministry of Energy of the Russian Federation is given. The analysis revealed that all protective structures are divided into 2 types - engineering and earth structures. The essence of main methods of active remote sensing is described: radar imaging, radar interferometry, aerial, mobile and ground laser scanning. Accuracy characteristics are given. Justification of monitoring methods application for various types of engineering structures is performed.

Laser Scanning Based Growth Analysis of Plants as a New Challenge for Deformation Monitoring

2016 ◽  
Vol 10 (1) ◽  
Author(s):  
Jan Dupuis ◽  
Christoph Holst ◽  
Heiner Kuhlmann
Keyword(s):  
Leaf Area ◽  
High Precision ◽  
Laser Scanning ◽  
Leaf Surface ◽  
Leaf Growth ◽  
Spline Approximation ◽  
Point Clouds ◽  
Deformation Monitoring ◽  
Deformation Analysis ◽  
Absolute Size

AbstractNowadays, the areal deformation analysis has become an important task in engineering geodesy. Thereby, not only manmade objects are of high interest, also natural objects, like plant organs, are focused more frequently. Thus, the analysis of leaf growth, i. e. the spatial development of the leaf surface, can be seen as a problem of deformation monitoring. In contrast to classical geodetic tasks, the absolute size of the deformation of the leaf surface is small, but usually great compared to the object size. Due to the optical characteristics of leaf surfaces, the point clouds, commonly acquired with high precision close-up laser scanners, provide a point-to-point distance that is small or equal compared to the measurement accuracy. Thus, the point clouds are usually processed and the leaf area is derived from a triangulation-based surface representation (mesh), resulting in a significant uncertainty of area calculation. In this paper, we illustrate the lacks of the mesh-based leaf area calculation. Using high precision gauge blocks as well as a number of tomato leaves, uncertainties of the area derivation are revealed and evaluated. The application of a B-spline approximation illustrates the advantages of an approximation-based approach and introduces the prospect for further research.

scholarly journals Spatial data analysis for laser scanning based shape error inspection

2021 ◽  
Author(s):  
Haibin Jia
Keyword(s):  
Fourier Transform ◽  
Spatial Data ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Industrial Applications ◽  
Spatial Data Analysis ◽  
Inspection System ◽  
Shape Error ◽  
Shape Errors ◽  
Weld Inspection

Laser scanning, a widely used technology, has been highly developed and adopted in various industrial applications. The methodologies used for scanner date processing are mostly point based. In this thesis, a new approach is presented to analyze spatial data obtained from a 3-D laser scanner for shape error inspection. Different from traditional methodologies, the method proposed in this research is frequency based. The method utilizes the Fourier transform to decompose a 2-D curve or 3-D shape into its spatial components by applying two 1-D FFT (Fast Fourier Transform) on 2-D curves or two 2-D FFT on 3-D shapes. The spatial components including frequency, amplitude, and phase are defined as shape characteristics to represent the shape under inspection. By relating spatial components with GD&T (Geometric Dimensioning and Tolerancing) standards using proper analysis techniques, such as frequency spectrum and cross correlation, shape errors can be detected and characterized. One of the applications of this method is automated inspection. In this research, the spatial data method is applied to MIG (Metal Inert Gas) weld inspection. Experiments are carried out to analyze the 2-D curve of a projection weld data, and the 3-D scanning data directly. A MIG weld inspection system is also developed for production use.

scholarly journals Technological Development and Application of Photo and Video Theodolites

2021 ◽  
Vol 11 (9) ◽  
pp. 3893
Author(s):  
Rinaldo Paar ◽  
Miodrag Roić ◽  
Ante Marendić ◽  
Stjepan Miletić
Keyword(s):  
Technological Development ◽  
Experimental Studies ◽  
Image Sensors ◽  
Commercial Application ◽  
Measuring Instruments ◽  
Engineering Structures ◽  
Essential Information ◽  
Advanced Development ◽  
Structural Diagnosis

Theodolites are fundamental geodetic measuring instruments for all practical geodetic tasks, as well as for experimental geodetic scientific purposes. Their development has a long history. Photo and video theodolites represent the advanced development of classic theodolites. Development started in 19th century, but only in the last 15 years has commercial application been achieved in the geodetic profession. The latest development, called image-assisted total stations (IATS), is a theodolite which consists of a classic robotic total station (RTS) with integrated image sensors. It was introduced in the early 2000s. With the development of theodolites, their application became much wider; today, they can be used for structural and geo-monitoring, i.e., for the determination of static and dynamic displacements and deformations of civil engineering structures such as bridges, dams, wind turbines, and high buildings, as well as natural structures, such as mountain slopes. They can be implemented in geodetic monitoring systems, which are an integral part of engineering structural diagnosis, and they provide essential information about the current condition of the structure. This paper describes the technological development of photo and video theodolites divided into phases according to the main innovations in their development. The application of modern video theodolites (i.e., IATS) is presented through several experimental studies that were performed. The procedure of conducting measurements with this kind of instrument, as well as the analysis of acquired data and achieved results, is elaborated. Lastly, the authors conclude, according to the achieved results, that IATS can today be used for determination of quasi-static and dynamic displacements with small and high amplitudes.

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