scholarly journals Applicability and Analysis of the Results of Non-Contact Methods in Determining the Vertical Displacements of Timber Beams

2021 ◽  
Vol 11 (19) ◽  
pp. 8936
Author(s):  
Boštjan Kovačič ◽  
Luka Štraus ◽  
Mateja Držečnik ◽  
Zoran Pučko
Keyword(s):  
Construction Projects ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Meteorological Conditions ◽  
Total Station ◽  
Engineering Geodesy ◽  
Vertical Displacements ◽  
Robotic Total Station ◽  
Timber Beams

Determining the displacements and consequent deformations of structures is a demanding branch of engineering. Displacements are most often determined by geodetic methods, among which high-precision non-contact methods have recently taken the lead. Engineering geodesy is an indispensable part of construction projects. In the desire for efficient and fast measurements, the technology of terrestrial laser scanning (TLS) and the use of robotic total station (RTS) and other geodetic methods are becoming more and more useful for engineers. In the presented study, we focused on the measurement and comparison of vertical displacements with various mentioned equipment and the determination of the influence of meteorological conditions on the displacements of timber beams that we used to perform the experiment. Measurements were performed both in the laboratory and outdoors. A novelty in the work was the use of a TLS scanner to determine the evaluation of small value displacements and the analysis of the usability of geodetic measuring equipment. In the Materials and Methods section, we describe the equipment used and the characteristics of the beams. The Results section describes the experimental outcomes, which include the performance of experimental analysis of vertical displacements of timber beams under different meteorological conditions. Altogether, the results consist of geodetic measurements and the processing of measured data. The results of measurements of vertical displacements with a terrestrial laser scanner were compared with the results obtained with a robotic total station were evaluated and compared with the displacements calculated from static analysis and the results of other methods used.

scholarly journals Point-Cloud Models of Historical Barns – Spatial Discrepancies of Laser Scanning versus Robotic Total Station

10.29007/2493 ◽  
2020 ◽  
Author(s):  
Gustavo Maldonado ◽  
Marcel Maghiar ◽  
Brent Tharp ◽  
Dhruv Patel
Keyword(s):  
Service Learning ◽  
Point Cloud ◽  
Laser Scanning ◽  
3D Point Cloud ◽  
Spatial Accuracy ◽  
Total Station ◽  
Cloud Models ◽  
Bulloch County ◽  
Southern University ◽  
Robotic Total Station

This study considers the generation of virtual, 3D point-cloud models of seven deteriorating historical, agricultural barns in Bulloch County, Georgia, USA, for preservation purposes. The work was completed as a service-learning project in a course on Terrestrial Light Detection and Ranging (T-LiDAR), offered at Georgia Southern University. The resulting models and fly-through videos were donated to Bulloch County Historical Society and to the Georgia Southern Museum, to make them available to the general public and future generations. Additionally, one of the seven barns was selected to be extensively measured to estimate the relative spatial accuracy of all seven resulting 3D point-cloud models, with respect to measurements completed with a highly accurate instrument. Three accurate benchmarks were established around it for georeferencing purposes. The positions of 44 points were measured in the field via an accurate, one- second, robotic total-station (RTS) instrument. Also, the coordinates of the same points were acquired from within georeferenced and non-georeferenced point-cloud models. These points defined 259 distances. They were compared to determine their discrepancy statistics. It was observed that this process produced virtual models with an approximate maximum spatial discrepancy of one-half inch (0.5 in) with respect to measurements performed by a highly accurate RTS device. There were no substantial differences in the relative accuracies of the georeferenced and non-georeferenced models.

Landslide monitoring using terrestrial laser scanner and robotic total station in Rancabali, West Java (Indonesia)

2017 ◽  
Author(s):  
Irwan Gumilar ◽  
Alif Fattah ◽  
Hasanuddin Z. Abidin ◽  
Vera Sadarviana ◽  
Nabila S. E. Putri ◽  
...  
Keyword(s):  
Laser Scanner ◽  
Landslide Monitoring ◽  
Terrestrial Laser Scanner ◽  
West Java ◽  
Total Station ◽  
Robotic Total Station

scholarly journals DETECTION OF BUILDING ROOFS AND FACADES FROM AERIAL LASER SCANNING DATA USING DEEP LEARNING

2019 ◽  
Vol XLII-2/W11 ◽  
pp. 975-980 ◽  
Author(s):  
F. Pirotti ◽  
C. Zanchetta ◽  
M. Previtali ◽  
S. Della Torre
Keyword(s):  
Deep Learning ◽  
Point Cloud ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Remote Sensing Data ◽  
Automatic Extraction ◽  
3D Mapping ◽  
Aerial Laser Scanning ◽  
Semantic Classes

<p><strong>Abstract.</strong> In this work we test the power of prediction of deep learning for detection of buildings from aerial laser scanner point cloud information. Automatic extraction of built features from remote sensing data is of extreme interest for many applications. In particular latest paradigms of 3D mapping of buildings, such as CityGML and BIM, can benefit from an initial determination of building geometries. In this work we used a LiDAR dataset of urban environment from the ISPRS benchmark on urban object detection. The dataset is labelled with eight classes, two were used for this investigation: roof and facades. The objective is to test how TensorFlow neural network for deep learning can predict these two classes. Results show that for “roof” and “facades” semantic classes respectively, recall is 84% and 76% and precision is 72% and 63%. The number and distribution of correct points well represent the geometry, thus allowing to use them as support for CityGML and BIM modelling. Further tuning of the hidden layers of the DL model will likely improve results and will be tested in future investigations.</p>

scholarly journals Non-Destructive Testing of the Longest Span Soil-Steel Bridge in Europe—Field Measurements and FEM Calculations

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3652 ◽  
Author(s):  
Mikołaj Miśkiewicz ◽  
Bartosz Sobczyk ◽  
Pawel Tysiac
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Field Measurements ◽  
Load Test ◽  
Steel Bridge ◽  
Good Correspondence ◽  
Total Station ◽  
Non Destructive ◽  
Inductive Sensors

The article describes interdisciplinary and comprehensive non-destructive diagnostic tests of final bridge inspection and acceptance proposed for a soil-steel bridge made of corrugated sheets, being the European span length record holder (25.74 m). As an effect of an original concept a detailed and precise information about the structure short-term response was collected. Periodic diagnostics of bridge deformations was done one year after it was built. Load test design was based on numerical simulations performed by means of finite element method (FEM). In situ measurements were done with the aid of: inductive sensors, optical total station, and terrestrial laser scanner. The results produced by terrestrial laser scanning were used to build a precise image of structure deformation in 3D space during the tests. The accuracy of laser mapping was significantly increased using the information coming from total station and inductive sensors. These have higher accuracy and therefore can be used as reference. Thus, new quality in measurements is introduced. Good correspondence between in situ values and FEM estimations was achieved. Therefore, such a combination of testing methods can be used in non-destructive diagnostics of structures and is an interesting alternative for the standard approach, in which the measurements are done in limited number of points.

scholarly journals Comparison of Different Measurement Techniques as Methodology for Surveying and Monitoring Stainless Steel Chimneys

Geosciences ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 429
Author(s):  
Daliga ◽  
Kurałowicz
Keyword(s):  
Stainless Steel ◽  
Reinforced Concrete ◽  
Laser Scanning ◽  
Measurement Techniques ◽  
Technical Condition ◽  
Significant Error ◽  
Long Distance ◽  
Total Station ◽  
Engineering Geodesy ◽  
Measurement Results

The measurement of a chimney axis is an engineering geodesy task. These measurements allow to assess the technical condition of chimneys and are usually carried out for reinforced concrete chimneys. When measuring high chimneys, the main problem may be the need to go a long distance to take a measurement. The surface of the chimney can also be problematic because it can absorb so much light from the range finder that total station reflectorless measurement or laser scanning will not be possible or will be affected by significant error. Chimneys made of stainless steel are also used today. They are not as high as reinforced concrete chimneys, but measuring them using reflectorless total stations or laser scanning can also be problematic. Problems arise from the reflective surface of these chimneys. The article presents a comparison of measurement results of a stainless steel chimney fragment obtained from total station measurement and laser scanning. Similarities and differences in the obtained axis of this chimney fragment are presented.

scholarly journals Determination of Geometrical Track Position by Robotic Total Station

2014 ◽  
Vol 91 ◽  
pp. 322-327 ◽  
Author(s):  
Jana Izvoltova ◽  
Andrej Villim ◽  
Peter Kozak
Keyword(s):  
Total Station ◽  
Robotic Total Station

scholarly journals Experimental comparison of altitudes with modern geodetic methods

2019 ◽  
Vol 110 ◽  
pp. 01030
Author(s):  
Boštjan Kovačič
Keyword(s):  
Data Analysis ◽  
Data Processing ◽  
Vertical Component ◽  
Data Capture ◽  
Experimental Comparison ◽  
Total Station ◽  
Gnss Measurements ◽  
Gnss Data ◽  
Robotic Total Station

Levelling is one of the most important geodesic works in construction and other interventions in space. Mostly, it is used for the needs of the altitude presentations of the terrain, to determine shifts, to determine the height of the object, and for various precise laboratory and scientific researches. When determining the shifts, the values are confirmed with the results of levelling, and deformations are calculated. There are a lot of methods to determine height differences; which one will be used, depends on the complexity of the works. Recently, the GNSS method is mostly used. It offers 2D positionally reliable results, whereas the vertical component does not provide reliable results. For this purpose, a series of tests and GNSS-measurements analysis were performed at our institution, which is also presented in the article as the GNSS-measurements analysis in comparison to the results obtained with the robotic total station of accuracy 0,5ˇ. Prior to the experiment, a temporal GNSS data analysis based on an individual axis and with a different way of data processing was carried out. The planning of GNSS-measurements for the needs of more demanding measurements is emphasised. To improve the determination of the vertical component, the data capture with GNSS method was increased from 10 Hz to 100 Hz, which partly improved the final values and is presented in the study.

scholarly journals DEVELOPING AND TESTING A METHOD FOR DEFORMATIONS MEASUREMENTS OF STRUCTURES

2017 ◽  
Vol 43 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Khalid L. A. El-ASHMAWY
Keyword(s):  
Accurate Determination ◽  
Dynamic Monitoring ◽  
Concentrated Load ◽  
Total Station ◽  
Vertical Displacements ◽  
Variable Displacement ◽  
One Step ◽  
The Stability ◽  
Displacement Transducers

Dynamic monitoring of structures is an important task in civil engineering that aims to determine the stability and safety of a structure by using information about its deformations. This paper describes the development of a method for the determination of structures deformations. The proposed method is developed to add a new solution to traditional methods of angle intersection and trigonometric leveling. It is designed to provide a simultaneous solution to all observations in one step using least squares solution to improve the expected accuracy and to generate the necessary data for statistical analysis. A practical experiment was made, where the observations of 7 deformation points on a simply supported steel beam with concentrated load were measured using the proposed method, total station and linear variable displacement transducers (LVDTs). Deflections measured directly from LVDTs were used as a reference for assessment of the serviceability of the beam. The results show that for the maximum deflection at mid-span of the beam, the differences between the measured deflections from LVDTs and proposed method are less than 0.87 mm corresponding to an error of 4.3%, while they are less than 1.32 mm causing an error of 12.5% for the case of total station measurements. Based on root mean square error values, the accuracy of point displacements determination using the proposed method is much better than total station measurements. The proposed method is suitable for the accurate determination of horizontal and vertical displacements and provides a realistic solution for monitoring structures at both entire structure and member levels.

scholarly journals Analysis of power lines span geometry based on TLS measurements

2018 ◽  
Vol 55 ◽  
pp. 00013
Author(s):  
Andrzej Kwinta ◽  
Karolina Ważydrąg ◽  
Mariusz Zygmunt
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Terrestrial Laser Scanning ◽  
Field Measurements ◽  
Power Lines ◽  
Classical Approach ◽  
Engineering Geodesy ◽  
Overhead Power Lines ◽  
To Receive

The inventory measurements of utility infrastructure are crucial issues in the field of engineering geodesy. Secure usage of power lines requires to monitor their geometry. According to classical approach to measurements of geometry of overhead power lines, it usually allows only to measure directly. Geodetic methods cannot be applied due to measuring limitations (lack of an appropriate area to conduct a measurement). Currently in engineering geodesy it is becoming more common to use methods of laser scanning as well as Unmanned Aerial Photogrammetric Survey. In the Paper, the procedure of determining of an overhead power line’s geometry is presented on the example of an one span measured with Terrestrial Laser Scanning methods. Field measurements were conducted by using laser scanner. Afterwards the point cloud was processed in order to receive the geometry of conductor. Finally, results were presented is tabular and graphic form.

scholarly journals Measuring Streambank Erosion: A Comparison of Erosion Pins, Total Station, and Terrestrial Laser Scanner

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1846 ◽  
Author(s):  
Daniel T. Myers ◽  
Richard R. Rediske ◽  
James N. McNair
Keyword(s):  
Laser Scanning ◽  
Measurement Techniques ◽  
Laser Scanner ◽  
Field Methods ◽  
Total Station ◽  
High Resolution Data ◽  
Streambank Erosion ◽  
Erosion Rates ◽  
Creek Watershed ◽  
Erosion Pins

Streambank erosion is difficult to quantify; models and field methods are needed to assess this important sediment source to streams. Our objectives were to (1) evaluate and compare three techniques for quantifying streambank erosion: erosion pins, total station, and laser scanning, (2) spatially assess streambank erosion rates in the Indian Mill Creek watershed of Michigan, USA, and (3) relate results with modeling of nonpoint source pollution. We found large absolute and relative errors between the different measurement techniques. However, we were unable to determine any statistically significant differences between techniques and only observed a correlation between total station and laser scanner. This suggests that the three methods have limited comparability and differences between measurements were largely not systemic. Further, the application of each technique should be dependent on site conditions, project goals, desired resolution, and resources. The laser scanner collected high-resolution data on clear, barren streambanks, but the erosion pin and total station were more representative of complex vegetated banks. Streambank erosion rates varied throughout the watershed and were influenced by fluvial processes. We estimate that streambank erosion contributed 28.5% of the creek’s total sediment load. These findings are important to address sources of watershed impairments related to sedimentation, as choosing an applicable technique for individual purposes can help reduce the challenges and costs of a streambank erosion study.

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