Handheld Laser Scanner Research

2019 ◽  
Vol 952 (10) ◽  
pp. 47-54
Author(s):  
A.V. Komissarov ◽  
A.V. Remizov ◽  
M.M. Shlyakhova ◽  
K.K. Yambaev

The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.

Teknik ◽  
2019 ◽  
Vol 39 (2) ◽  
pp. 94
Author(s):  
Yudo Prasetyo

Teknologi dokumentasi gedung secara spasial untuk konservasi dan perencanaan tata ruang semakin berkembang pesat. Urgensi tingkat ketelitian dalam suatu pengukuran juga dituntut semakin tinggi. Salah satu teknologi pembentukan objek tiga dimensi yang berkembang saat ini adalah Terrestrial Laser Scanner (TLS). Metode pengukuran TLS terdiri atas 4 metode yaitu: Cloud to Cloud, Target to Target, Traverse, dan metode kombinasi. Penelitian ini bertujuan untuk menganalisa tingkat ketelitian metode Traverse dalam pengukuran suatu objek model tiga dimensi untuk keperluan dokumentasi gedung menggunakan TLS.Ketelitian metode Traverse akan diujikan pada Gedung Prof. H. Soedarto, S. H. Tingkat ketelitiannya diujikan pada dua parameter yakni hasil metode registrasi dan hasil visualisasi model tiga dimensi. Hasil analisis pengolahan data point cloud menunjukkan bahwa alat TLS dengan metode Traverse dapat digunakan untuk menghasilkan model tiga dimensi Gedung Prof. Sudarto, S. H. Nilai rata-rata validasi yang diperoleh adalah sebesar 0,004 meter dengan besaran ketelitian model RMSE sebesar ±0,00611 meter. 


2011 ◽  
Vol 94-96 ◽  
pp. 86-89
Author(s):  
Wen Long Liu ◽  
Xiao Ping Zhao ◽  
Bao Guo Xu

Starting from the principle of three-dimensional laser scanner and after analyzing the positioning error of point cloud, in this paper the following key problems confronted in data processing are researched ,the problems are range image segmentation, point cloud registration, point cloud filtering, absolute positioning and stitching data, modeling in AutoCAD or 3Dmax. Then, examples were introduced in constructing three-dimensional model using laser scanning technology. The results showed that the use of this technology can provide high-precision building models, which is important in constructing three-dimensional models and very helpful of digital cities.


Author(s):  
R. Voges ◽  
C. S. Wieghardt ◽  
B. Wagner

Motor actuated 2D laser scanners are key sensors for many robotics applications that need wide ranging but low cost 3D data. There exist many approaches on how to build a 3D laser scanner using this technique, but they often lack proper synchronization for the timestamps of the actuator and the laser scanner. However, to transform the measurement points into three-dimensional space an appropriate synchronization is mandatory. Thus, we propose two different approaches to accomplish the goal of calculating timestamp offsets between laser scanner and motor prior to and after data acquisition. Both approaches use parts of a SLAM algorithm but apply different criteria to find an appropriate solution. While the approach for offset calculation prior to data acquisition exploits the fact that the SLAM algorithm should not register motion for a stationary system, the approach for offset calculation after data acquisition evaluates the perceived clarity of a point cloud created by the SLAM algorithm. Our experiments show that both approaches yield the same results although operating independently on different data, which demonstrates that the results reflect reality with a high probability. Furthermore, our experiments exhibit the significance of a proper synchronization between laser scanner and actuator.


2019 ◽  
Vol 9 (18) ◽  
pp. 3884 ◽  
Author(s):  
Dabove ◽  
Grasso ◽  
Piras

The geomatic survey in the speleological field is one of the main activities that allows for the adding of both a scientific and popular value to cave exploration, and it is of fundamental importance for a detailed knowledge of the hypogean cavity. Today, the available instruments, such as laser scanners and metric cameras, allow us to quickly acquire data and obtain accurate three-dimensional models, but they are still expensive, require a careful planning phase of the survey, as well as some operator experience for their management. This work analyzes the performance of a smartphone device for a close-range photogrammetry approach for the extraction of accurate three-dimensional information of an underground cave. The image datasets that were acquired with a high-end smartphone were processed using the Structure from Motion (SfM)-based approach for dense point cloud generation: different image-matching algorithms implemented in a commercial and an open source software and in a smartphone application were tested. In order to assess the reachable accuracy of the proposed procedure, the achieved results were compared with a reference dense point cloud obtained with a professional camera or a terrestrial laser scanner. The approach has shown a good performance in terms of geometrical accuracies, computational time and applicability.


Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 201
Author(s):  
Michael Bekele Maru ◽  
Donghwan Lee ◽  
Kassahun Demissie Tola ◽  
Seunghee Park

Modeling a structure in the virtual world using three-dimensional (3D) information enhances our understanding, while also aiding in the visualization, of how a structure reacts to any disturbance. Generally, 3D point clouds are used for determining structural behavioral changes. Light detection and ranging (LiDAR) is one of the crucial ways by which a 3D point cloud dataset can be generated. Additionally, 3D cameras are commonly used to develop a point cloud containing many points on the external surface of an object around it. The main objective of this study was to compare the performance of optical sensors, namely a depth camera (DC) and terrestrial laser scanner (TLS) in estimating structural deflection. We also utilized bilateral filtering techniques, which are commonly used in image processing, on the point cloud data for enhancing their accuracy and increasing the application prospects of these sensors in structure health monitoring. The results from these sensors were validated by comparing them with the outputs from a linear variable differential transformer sensor, which was mounted on the beam during an indoor experiment. The results showed that the datasets obtained from both the sensors were acceptable for nominal deflections of 3 mm and above because the error range was less than ±10%. However, the result obtained from the TLS were better than those obtained from the DC.


Author(s):  
Hatice Çiğdem ZAĞRA ◽  
Sibel ÖZDEN

Aim: This study aims to comparatively evaluate the use potential of orthophoto images obtained by terrestrial laser scanning technologies on an urban scale through the "Old Lapseki Finds Life Project" prepared using terrestrial laser scanning technologies and the "Enez Historical City Square Project" prepared using traditional methods. Method: In the study, street improvement projects of 29.210 m2 Lapseki and 29.214 m2 Enez city designed on an urban scale were evaluated and compared with descriptive statistics based on different parameters. Results: In the study, it has been determined that terrestrial laser (point cloud) technologies are 99,9% accurate when compared to traditional methods, save time by 83,08% and reduce workforce by 80%. In addition, it has been determined that terrestrial laser scanning technologies accelerate project processes compared to traditional methods. Conclusion: In this study, the use of laser scanning technologies, which are basically reverse engineering applications, in architectural restoration projects, determination of the current situation and damage, architectural documentation of structures and preparation of three-dimensional models, in terms of efficiency in survey studies are evaluated. It has been observed that orthophoto images obtained by terrestrial laser scanning technologies in architectural relief-restoration-restitution projects have potentials' worth using in different stages of the project.


2013 ◽  
Vol 14 (2) ◽  
pp. 265-268 ◽  
Author(s):  
Naveen S Yadav ◽  
Teerthesh Jain ◽  
Amrita Pandita ◽  
SMA Feroz ◽  
Pradeep LNU ◽  
...  

ABSTRACT Aim Aim of the present study was to comparatively evaluate dimensional accuracy of newely introduced elastomeric impression material after repeated pours at different time intervals. Materials and methods In the present study a total of 20 (10 + 10) impressions of master model were made from vinyl polyether silicone and vinyl polysiloxane impression material. Each impression was repeatedly poured at 1, 24 hours and 14 days. Therefore, a total of 60 casts were obtained. Casts obtained were scanned with three-dimensional (3D) laser scanner and measurements were done. Results Vinyl polyether silicone produced overall undersized dies, with greatest change being 0.14% only after 14 days. Vinyl polysiloxane produced smaller dies after 1 and 24 hours and larger dies after 14 days, differing from master model by only 0.07% for the smallest die and to 0.02% for the largest die. Conclusion All the deviations measured from the master model with both the impression materials were within a clinically acceptable range. Clinical significance In a typical fixed prosthodontic treatment accuracy of prosthesis is critical as it determines the success, failure and the prognosis of treatment including abutments. This is mainly dependent upon fit of prosthesis which in turn is dependent on dimensional accuracy of dies, poured from elastomeric impressions. How to cite this article Pandita A, Jain T, Yadav NS, Feroz SMA, Pradeep, Diwedi A. Evaluation and Comparison of Dimensional Accuracy of Newly Introduced Elastomeric Impression Material using 3D Laser Scanners: An in vitro Study. J Contemp Dent Pract 2013;14(2):265-268.


Author(s):  
Katarzyna Bobkowska ◽  
Jakub Szulwic ◽  
Paweł Tysiac ◽  
Patryk Ziółkowski

The integration issue of virtual models and geo-referenced database have a very broad spectrum of potential applications. Before the integration issue was on the cusp, it was quite problematic to combine three-dimensional models with the geo-referenced database. An integrated database contains a variety of data including such as object orientated data model and raster data. Within this paper, authors present an integration process aiming to make real virtual GIS database which includes the creation of structures, such as bridges, buildings, roads and terrain formations. To create a three-dimensional GIS model high-resolution satellite images/point cloud has been used. For 3D modelling and reconstruction purposes, The Blender program has been used since the software provides with quick workflow and userfriendly interface. As a result of this study authors concede that integrated techniques for three-dimensional GIS databases allow conducting easy as well as sophisticated operation in an efficient and non-time consuming way. The subject holds great promise for a future, current challenges focusing on new approaches for conjectures of spatial objects that will be used to boost the capabilities for automatic visualization.


Author(s):  
I. I. Bayneva ◽  
N. S. Komarov

The article discusses optical systems for LED lighting devices, the principles of the propagation of rays in lenses of various designs. Analyzed the features of the secondary use of the optical elements in the form of lenses and prisms for different LED emission patterns in space. Considered the features and problems of calculation of the secondary optical systems. Problems and prospects of application are considered, research and computer modeling of optics, which is used to form the required light distribution in LED light devices. Computer modeling technologies and the mathematical methods that underlie them determine the possibility of developing such optical systems in lighting installations. The article considers the numerical Monte Carlo simulation method, which allows one to organize ray tracing modeling in optical systems. The TracePro software package for modeling and research of lighting devices and their optical elements allows you to automate the stage of their calculation and design, this significantly reduces the cost of developing new products. The prototyping of three-dimensional models of lens systems opens up great opportunities for manufacturers of optics for LEDs, allows research on prototypes planned for production of serial products.


2018 ◽  
Vol 14 (3) ◽  
pp. 155014771876645 ◽  
Author(s):  
Ashok Kumar Patil ◽  
G Ajay Kumar ◽  
Tae-Hyoung Kim ◽  
Young Ho Chai

Acquiring the three-dimensional point cloud data of a scene using a laser scanner and the alignment of the point cloud data within a real-time video environment view of a camera is a very new concept and is an efficient method for constructing, monitoring, and retrofitting complex engineering models in heavy industrial plants. This article presents a novel prototype framework for virtual retrofitting applications. The workflow includes an efficient 4-in-1 alignment, beginning with the coordination of pre-processed three-dimensional point cloud data using a partial point cloud from LiDAR and alignment of the pre-processed point cloud within the video scene using a frame-by-frame registering method. Finally, the proposed approach can be utilized in pre-retrofitting applications by pre-generated three-dimensional computer-aided design models virtually retrofitted with the help of a synchronized point cloud, and a video scene is efficiently visualized using a wearable virtual reality device. The prototype method is demonstrated in a real-world setting, using the partial point cloud from LiDAR, pre-processed point cloud data, and video from a two-dimensional camera.


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