scholarly journals Evaluation of the Metrological Performance of a Handheld 3D Laser Scanner Using a Pseudo-3D Ball-Lattice Artifact

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2137
Author(s):  
Rémi Bonin ◽  
Farbod Khameneifar ◽  
J.R.R. Mayer
Keyword(s):  
Exposure Time ◽  
Figure Of Merit ◽  
Single Point ◽  
Laser Scanner ◽  
Considerable Effect ◽  
Measuring Volume ◽  
Scan Data ◽  
Single Figure ◽  
Metrological Performance ◽  
Independent Parameters

This paper proposes the use of a pseudo-3D ball-lattice artifact to characterize a handheld laser scanner from a metrological standpoint. The artifact allows the computation of local and global errors in measurement by using the reference-frame-independent parameters of size, form, and distance within the measuring volume of the scanner, and in a single point cloud, without the need for registration. A set of tests was performed using the whole measuring volume, and three acquisition parameters, namely the orientation of the sweeps during the scans, the exposure time, and the distance to the scanner were analyzed for their effects on the accuracy of the scan data. A composite error including the errors in measuring size, form, and distance was used as a single figure of merit to characterize the performance of the scanner in relation to the data-acquisition parameters. The orientation of sweeps did not have a considerable effect on the errors. The accuracy of the scan data was strongly affected by exposure time and its interaction with the distance at which the artifact was scanned. The errors followed a quadratic trend with respect to the distance of the artifact to the scanner. The tested scanner performed best at its manufacturer’s recommended stand-off distance.

The Steam Turbine Retrofitting of Six Boiling Water Reactor Units Using Innovative Engineering and Laser Scanning Techniques

2009 ◽  
Author(s):  
Mike Jones ◽  
David J. Nelmes
Keyword(s):  
Steam Turbine ◽  
Laser Scanning ◽  
Laser Scanner ◽  
Boiling Water ◽  
Boiling Water Reactors ◽  
Extensive Experience ◽  
Turbine Generators ◽  
The Usa ◽  
Water Reactors ◽  
Scan Data

Alstom Power is executing the steam turbine retrofit of six nuclear units for Exelon Generation in the USA. The existing turbine-generators are an 1800 RPM General Electric design originally rated at 912 MWe and 1098 MWe and powered by Boiling Water Reactors. 18 Low Pressure inner modules will be replaced, with the first due to be installed in March 2010. This project is particularly challenging — the aggressive retrofit installation schedule is compounded by the requirement to handle radioactively contaminated equipment and also comply with demanding regulations applicable to BWR plant. The author’s company has extensive experience in the steam turbine retrofit business, having supplied around 800 retrofit cylinders globally since the 1970’s. However, this LP upgrade challenges the established techniques used in the business and requires extraordinary effort. Traditional retrofit engineering and installation principles have been interrogated and developed to meet the specific requirements of this project. Innovative techniques are introduced, including the extensive use of the Leica HDS 6000 laser scanner to model the existing plant. The approach has advanced the field of steam turbine retrofit design and installation significantly. The first section of this paper focuses on the extraordinary considerations of the project and the challenges surrounding BWR plant. The second part describes the laser scanning technique and the application of scan data. It outlines the innovative solutions which have been developed.

scholarly journals TECHNIQUE OF AUTOMATIC MOBILE LASER SCANNING DATA FILTERING

2021 ◽  
Vol 26 (3) ◽  
pp. 5-19
Author(s):  
Maxim A. Altyntsev ◽  
◽  
Hamid Majid Saber Karkokli ◽  
Keyword(s):  
Laser Scanning ◽  
Single Point ◽  
Laser Scanner ◽  
Digital Terrain Model ◽  
Weather Conditions ◽  
Automatic Generation ◽  
Data Filtering ◽  
Terrain Model ◽  
Digital Terrain ◽  
Filtration Technique

The result of laser scanning is an array of laser points. The generation of a single point cloud in a given coordinate system is carried out during the registration process at the stage of preliminary field data processing. At this stage it is also often necessary to filter the data. Laser points with an erroneous position are eliminated during the data filleting. The number of erroneous laser points is determined by the of the laser scanner characteristics, surveyed area peculiarities and weather conditions. The devel-opment of methods and algorithms for filtering laser scanning data is carried out based on the analysis of the laser point spatial position and a certain set of additional characteristics, such as intensity value, echo signal, color value. The technique of mobile laser scanning data filtering for the territory of the road passing among the forest and close to individual industrial facilities and building. The main goal of the proposed filtration technique is to obtain data for automatic generation of an accurate digital terrain model. The filtration technique was developed for data acquired under the least favorable con-ditions – in wet weather. Accuracy estimation of generating digital terrain model based on filtered data was carried out.

Towards Combining Digitization Techniques in the Generation of Reverse Engineering Data Sets

1999 ◽  
Author(s):  
C. J. Rolls ◽  
W. ElMaraghy ◽  
H. ElMaraghy
Keyword(s):  
Reverse Engineering ◽  
Computer Aided Design ◽  
Laser Scanning ◽  
Single Point ◽  
Laser Scanner ◽  
Coordinate Measuring Machine ◽  
Industrial Applications ◽  
Data Sets ◽  
Error Characterization ◽  
Measuring Machine

Abstract Reverse engineering (RE), may be defined as the process of generating computer aided design models (CAD) from existing or prototype parts. The process has been used for many years in industry. It has markedly increased in implementation in the past few years, primarily due to the introduction of rapid part digitization technologies. Current industrial applications include CAD model construction from artisan geometry, such as in automotive body styling, the generation of custom fits to human surfaces, and quality control. This paper summarizes the principles of operation behind many commercially available part digitization technologies, and discusses techniques involved in part digitization using a coordinate measuring machine (CMM) and laser scanner. An overall error characterization of the laser scanning digitization process is presented for a particular scanner. This is followed by a discussion of the merits and considerations involved in generating combined data sets with characteristics indicative of the design intent of specific part features. Issues in facilitating the assembly, or registration, of the different types of data into a single point set are discussed.

scholarly journals Archiving CCD/Electronic Astronomical Data

1992 ◽  
Vol 9 ◽  
pp. 713-714
Author(s):  
David Huenemoerder
Keyword(s):  
Exposure Time ◽  
Figure Of Merit ◽  
Dynamic Range ◽  
Two Dimensional ◽  
Large Format ◽  
Astronomical Data ◽  
Large Size ◽  
Astronomical Imaging ◽  
Charge Coupled Devices ◽  
Imaging And Spectroscopy

The availability and advances in two-dimensional electronic detectors, in particular the charge-coupled-devices (CCDs), are a great asset to astronomical imaging and spectroscopy because of their sensitivity, dynamic range, and linearity. In some cases photographic plates still offer an advantage to imaging of large size, but the advent of large format CCDs may make a figure of merit, the area per exposure time, much more favorable for CCDs.

scholarly journals Remote Indoor Construction Progress Monitoring Using Extended Reality

2020 ◽  
Author(s):  
Ahmed Khairadeen Ali ◽  
One Jae Lee ◽  
DoYeop Lee ◽  
Chansik Park
Keyword(s):  
Real Time ◽  
Data Exchange ◽  
Progress Monitoring ◽  
Laser Scanner ◽  
Visual Programming ◽  
Inspection System ◽  
Cloud Data ◽  
Recent Developments ◽  
Scan Data ◽  
Processing And Storage

Despite recent developments in monitoring and visualizing construction progress, the data exchange between construction jobsite and office lacks automation and real-time recording. To address this issue, a near real-time construction work inspection system called iVR is proposed; this system integrates 3D scanning, extended reality, and visual programming to visualize interactive onsite inspection for indoor activities and provide numeric data. iVR comprises five modules: iVR-location finder (finding laser scanner located in the construction site) iVR-scan (capture point cloud data of jobsite indoor activity), iVR-prepare (processes and convert 3D scan data into a 3D model), iVR-inspect (conduct immersive visual reality inspection in construction office), and iVR-feedback (visualize inspection feedback from jobsite using augmented reality). An experimental lab test is conducted to validate the applicability of iVR process; it successfully exchanges required information between construction jobsite and office in a specific time. This system is expected to assist Engineers and workers in quality assessment, progress assessments, and decision-making which can realize a productive and practical communication platform, unlike conventional monitoring or data capturing, processing, and storage methods, which involve storage, compatibility, and time-consumption issues.

EXPERIENCE OF USING GLS-1500 SCANNER IN ENGINEERING-GEODETIC SURVEYING OF ROADS

2019 ◽  
Vol 13 (2) ◽  
pp. 26-34
Author(s):  
B. F. Azarov
Keyword(s):  
Laser Scanning ◽  
Laser Scanner ◽  
Field Work ◽  
Optimal Time ◽  
Data Processing Software ◽  
Federal Highway ◽  
Geodetic Control ◽  
Scan Data ◽  
Estimation Of Time ◽  
Geodetic Surveying

Abstract: modern geodetic technologies allow us to quickly obtain relevant, precise and reliable geospatial data. An example of such a technology is ground-based laser scanning. Currently, this technology is actively used in the performance of engineering and geodetic surveys of roads. The devices and software of different companies are used, differing in their accuracy characteristics and functionality. The article focuses on the experience of the use of GLS-1500 ground-based laser scanner produced by TOPCON and ScanMaster ground-based laser scanning data processing software for engineering and geodetic surveys in order to repair nine sections of the Federal highway R-256 "Chuysky tract" with a total length of over than 100 km. The article also describes the options used for registration of scanning data, the features of their use depending on the availability of geodetic control on the object. The order of processing the results of ground-based laser scanning using ScanMaster software is considered. According to the results of field work on ground-based laser scanning of nine sections of the R-256 highway, the time and accuracy of scanning data were estimated. The method of estimation of time spent on scanning works is also described. The issue of evaluating the accuracy of obtaining the scan data in the ScanMaster software is considered. It is noted that the accuracy of the geodetic reference, thus, the accuracy of the absolute orientation of the scans can be estimated by the differences between the coordinates of the marks that were scanned from the location of the device and calculated by ScanMaster software, and their specified values obtained from the equalization of the geodetic control. In conclusion, it is stated that the optimal time and accuracy of scanning with GLS-1500 device are achieved by using the geodetic reference of the scans by the inverse length-angle intersection at two points of the geodetic control.

scholarly journals COMPARISON WITH ACCURACY OF TERRESTRIAL LASER SCANNER BY USING POINT CLOUD ALIGNED WITH SHAPE MATCHING AND BEST FITTING METHODS

2019 ◽  
Vol XLII-2/W9 ◽  
pp. 535-541 ◽  
Author(s):  
T. Ogawa ◽  
Y. Hori
Keyword(s):  
Laser Scanning ◽  
Shape Matching ◽  
Laser Scanner ◽  
Point Clouds ◽  
Random Errors ◽  
Laser Scanners ◽  
Error Distributions ◽  
Best Fitting ◽  
Scan Data ◽  
Fitting In

<p><strong>Abstract.</strong> Recently operation systems of laser scanning have been obviously improved; for instance shape matching has been equipped with software on a post processing stage so measurement without any targets is a prerequisite condition of field surveying with laser scanners. Moreover a shape matching method enables us to easily register a pair of point clouds with some errors even if those data are scanned by several type scanners. Those slightly errors can influence accuracy of alignments if the object is large to require a lot of scans. Laser scanning data has random errors and accuracy of alignments can be improved by matching error distributions of pairs of point clouds to natural distributions. This method is called “best fitting” in contrast “shape matching” in a software, PolyWorks |Inspector. In this paper, accuracy of alignments between shape matching and best fitting is discussed. The scan data of three phaseshift laser scanners (FARO Focus 3D MS120, FARO Focus 3D X330 and Z+F Imager 5016) and two time-of-flight scanners (Leica BLK 360 and Leica Scan station C5) are used for analyses. Accuracy of alignments by using shape matching and best fitting methods is demonstrated by showing points of scan data with histograms of error distributions.</p>

Impact of spatial correlations on the surface estimation based on terrestrial laser scanning

2017 ◽  
Vol 11 (3) ◽  
Author(s):  
Tobias Jurek ◽  
Heiner Kuhlmann ◽  
Christoph Holst
Keyword(s):  
Parameter Estimation ◽  
Stochastic Model ◽  
Laser Scanning ◽  
Colored Noise ◽  
Functional Model ◽  
Laser Scanner ◽  
Spatial Correlations ◽  
Global Test ◽  
Scan Data ◽  
The Impact

AbstractIn terms of high precision requested deformation analyses, evaluating laser scan data requires the exact knowledge of the functional and stochastic model. If this is not given, a parameter estimation leads to insufficient results. Simulating a laser scanning scene provides the knowledge of the exact functional model of the surface. Thus, it is possible to investigate the impact of neglecting spatial correlations in the stochastic model. Here, this impact is quantified through statistical analysis.The correlation function, the number of scanning points and the ratio of colored noise in the measurements determine the covariances in the simulated observations. It is shown that even for short correlation lengths of less than 10 cm and a low ratio of colored noise the global test as well as the parameter test are rejected. This indicates a bias and inconsistency in the parameter estimation. These results are transferable to similar tasks of laser scanner based surface approximation.

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