scholarly journals Terrestrial Laser Scanners Pre-Processing: Registration and Georeferencing

2014 ◽  
Vol 71 (4) ◽  
Author(s):  
Mohd Azwan Abbas ◽  
Lau Chong Luh ◽  
Halim Setan ◽  
Zulkepli Majid ◽  
Albert K. Chong ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Laser Scanner ◽  
Error Sources ◽  
High Data ◽  
3D Data ◽  
Laser Scanners ◽  
Contact Sensor ◽  
The Many ◽  
3D Applications

Terrestrial laser scanner (TLS) is a non-contact sensor, optics-based instrument that collects three dimensional (3D) data of a defined region of an object surface automatically and in a systematic pattern with a high data collecting rate. This capability has made TLS widely applied for numerous 3D applications. With the ability to provide dense 3D data, TLS has improved the processing phase in constructing complete 3D model, which is much simpler and faster. Pre-processing is one of the phases involved, which consisted of registration and georeferencing procedures. Due to the many error sources occur in TLS measurement, thus, pre-processing can be considered as very crucial phase to identify any existence of errors and outliers. Any presence of errors in this phase can decrease the quality of TLS final product. With intention to discuss about this issue, this study has performed two experiments, which involved with data collection for land slide monitoring and 3D topography. By implementing both direct and indirect pre-processing method, the outcomes have indicated that TLS is suitable for applications which require centimetre level of accuracy.

scholarly journals Investigation of Systematic Errors for the Hybrid and Panoramic Scanners

2014 ◽  
Vol 71 (4) ◽  
Author(s):  
Mohd Azwan Abbasa ◽  
Halim Setan ◽  
Zulkepli Majid ◽  
Albert K. Chong ◽  
Lau Chong Luh ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Error Sources ◽  
System Calibration ◽  
Vertical Circle ◽  
3D Data ◽  
Short Period ◽  
Laser Scanners ◽  
The Many ◽  
Different Sources

The existence of terrestrial laser scanners (TLSs) with capability to provide dense three-dimensional (3D) data in short period of time has made it widely used for the many purposes such as documentation, management and analysis. However, similar to other sensors, data obtained from TLSs also can be impaired by errors coming from different sources. Then, calibration routine is crucial for the TLSs to ensure the quality of the data. Through self-calibration, this study has performed system calibration for hybrid (Leica ScanStation C10) and panoramic (Faro Photon 120) scanner at the laboratory with dimensions 15.5m x 9m x 3m and more than hundred planar targets that were fairly distributed. Four most significant parameters are derived from well-known error sources of geodetic instruments as constant (a0), collimation axis (b0), trunnion axis (b1) and vertical circle index (c0) errors. Data obtained from seven scan-stations were processed, and statistical analysis (e.g. t-test) has shown significant errors for the calibrated scanners.

INVESTIGATION OF DATUM CONSTRAINTS EFFECT IN TERRESTRIAL LASER SCANNER SELF-CALIBRATION

2015 ◽  
Vol 75 (10) ◽  
Author(s):  
Mohd Azwan Abbas ◽  
Halim Setan ◽  
Zulkepli Majid ◽  
Albert K. Chong ◽  
Lau Chong Luh ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Laser Scanner ◽  
Terrestrial Laser Scanner ◽  
Network Configuration ◽  
Self Calibration ◽  
3D Data ◽  
Minimum Number ◽  
3D Applications

The ability to provide rapid and dense three-dimensional (3D) data have made many 3D applications easier. However, similar to other optical and electronic instruments, data from TLS can also be impaired with errors. Self-calibration is a method available to investigate those errors in TLS observations which has been adopted from photogrammetry technique. Though, the network configuration applied by both TLS and photogrammetry techniques are quite different. Thus, further investigation is required to verify whether the photogrammetry principal regarding datum constraints selection is applicable to TLS self-calibration. To ensure that the assessment is thoroughly done, the datum constraints analyses were carried out using three variant network configurations: 1) minimum number of scan stations, 2) minimum number of surfaces for targets distribution, and 3) minimum number of point targets. Via graphical and statistical, the analyses of datum constraints selection have indicated that the parameter correlations obtained are significantly similar.  

scholarly journals TIMESTAMP OFFSET DETERMINATION BETWEEN AN ACTUATED LASER SCANNER AND ITS CORRESPONDING MOTOR

2017 ◽  
Vol IV-1/W1 ◽  
pp. 99-106 ◽  
Author(s):  
R. Voges ◽  
C. S. Wieghardt ◽  
B. Wagner
Keyword(s):  
Data Acquisition ◽  
Point Cloud ◽  
Dimensional Space ◽  
Low Cost ◽  
Three Dimensional ◽  
Laser Scanner ◽  
3D Data ◽  
Laser Scanners ◽  
Slam Algorithm ◽  
Three Dimensional Space

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.

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
Keyword(s):  
Point Cloud ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Test Site ◽  
Optical Systems ◽  
Advantages And Disadvantages ◽  
Site Survey ◽  
Laser Scanners ◽  
Three Dimensional Models ◽  
The Stability

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.

scholarly journals Evaluation and Comparison of Dimensional Accuracy of Newly Introduced Elastomeric Impression Material using 3D Laser Scanners: An in vitro Study

2013 ◽  
Vol 14 (2) ◽  
pp. 265-268 ◽  
Author(s):  
Naveen S Yadav ◽  
Teerthesh Jain ◽  
Amrita Pandita ◽  
SMA Feroz ◽  
Pradeep LNU ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Laser Scanner ◽  
In Vitro Study ◽  
Dimensional Accuracy ◽  
Time Intervals ◽  
Impression Material ◽  
Impression Materials ◽  
Laser Scanners ◽  
Master Model

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.

scholarly journals 3D DIGITIZING TECHNOLOGY IN PRODUCT REVERSE DESIGN

2011 ◽  
Author(s):  
Qingjin Peng ◽  
Hector Sanchez
Keyword(s):  
Shape Recovery ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Coordinate Measuring Machine ◽  
Cost Effective ◽  
3D Shape ◽  
3D Data ◽  
Cost Effective Approach ◽  
Measuring Machine ◽  
And Performance

The reverse design develops new products based on the improvement of existing products. The shape recovery of three-dimensional (3D) objects is the basis of the product reverse design. 3D digitization technology is an important tool for the 3D shape recovery. This paper analyses the current 3D data acquisition technology. The accuracy and performance of the 3D laser scanner is evaluated. A cost-effective approach is proposed to recover 3D shape of objects using a structured-light technique. Details of the proposed method are described. Application examples are presented. The accuracy is evaluated using a coordinate measuring machine.

scholarly journals Reality Capture of Buildings Using 3D Laser Scanners

2021 ◽  
Author(s):  
Avar Almukhtar ◽  
Henry Abanda ◽  
Zaid O. Saeed ◽  
Joseph H.M. Tah
Keyword(s):  
Point Cloud ◽  
Laser Scanning ◽  
Construction Project ◽  
Laser Scanner ◽  
Data File ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Laser Scanners ◽  
Project Data

The urgent need to improve performance in the construction industry has led to the adoption of many innovative technologies. 3D laser scanners are amongst the leading technologies being used to capture and process assets or construction project data for use in various applications. Due to its nascent nature, many questions are still unanswered about 3D laser scanning, which in turn contribute to the slow adaptation of the technology. Some of these include the role of 3D laser scanners in capturing and processing raw construction project data. How accurate is the 3D laser scanner or point cloud data? How does laser scanning fit with other wider emerging technologies such as Building Information Modelling (BIM)? This study adopts a proof-of-concept approach, which in addition to answering the afore-mentioned questions, illustrates the application of the technology in practice. The study finds that the quality of the data, commonly referred to as point cloud data is still a major issue as it depends on the distance between the target object and 3D laser scanner’s station. Additionally, the quality of the data is still very dependent on data file sizes and the computational power of the processing machine. Lastly, the connection between laser scanning and BIM approaches is still weak as what can be done with a point cloud data model in a BIM environment is still very limited. The aforementioned findings reinforce existing views on the use of 3D laser scanners in capturing and processing construction project data.

Segmentation of Noisy Laser-Scanner Generated Meshes With Piecewise Polynomial Approximations

2004 ◽  
Author(s):  
Miguel Vieira ◽  
Kenji Shimada
Keyword(s):  
Real World ◽  
Feature Detection ◽  
Three Dimensional ◽  
Laser Scanner ◽  
User Interaction ◽  
Seed Region ◽  
Surface Boundary ◽  
Scanner Data ◽  
Laser Scanners ◽  
Polynomial Surface

Laser scanners offer a fast and simple way of collecting large amounts of geometric data from real-world objects. Although this aspect makes them attractive for design and reverse engineering, the laser-scanner data is often noisy and not partitioned into meaningful surfaces. A good partitioning, or segmentation, of the scanner data has uses including feature detection, surface boundary generation, surface fitting, and surface reconstruction. This paper presents a method for segmenting noisy three-dimensional surface meshes created from laser-scanned data into distinct regions closely approximated by explicit surfaces. The algorithm first estimates mesh curvatures and noise levels and then uses the curvature data to construct seed regions around each vertex. If a seed region meets certain criteria, it is assigned a region number and is grown into a set of connected vertices approximated by a bicubic polynomial surface. All the vertices in a region are within known distance and surface normal tolerances from their underlying surface approximations. The algorithm works on noisy or smooth data and requires little or no user interaction. We demonstrate the effectiveness of the segmentation on real-world examples.

scholarly journals Hybrid 3D Models: When Geomatics Innovations Meet Extensive Built Heritage Complexes

2019 ◽  
Vol 8 (3) ◽  
pp. 124 ◽  
Author(s):  
Filiberto Chiabrando ◽  
Giulia Sammartano ◽  
Antonia Spanò ◽  
Alessandra Spreafico
Keyword(s):  
Three Dimensional ◽  
Laser Scanner ◽  
3D Models ◽  
Satellite System ◽  
3D Data ◽  
Mapping System ◽  
Aerial Vehicle ◽  
Mobile Mapping System ◽  
Global Navigation Satellite ◽  
Topographic Surveys

This article proposes the use of a multiscale and multisensor approach to collect and model three-dimensional (3D) data concerning wide and complex areas to obtain a variety of metric information in the same 3D archive, which is based on a single coordinate system. The employment of these 3D georeferenced products is multifaceted and the fusion or integration among different sensors’ data, scales, and resolutions is promising, and it could be useful in the generation of a model that could be defined as a hybrid. The correct geometry, accuracy, radiometry, and weight of the data models are hereby evaluated when comparing integrated processes and results from Terrestrial Laser Scanner (TLS), Mobile Mapping System (MMS), Unmanned Aerial Vehicle (UAV), and terrestrial photogrammetry, while using Total Station (TS) and Global Navigation Satellite System (GNSS) for topographic surveys. The entire analysis underlines the potentiality of the integration and fusion of different solutions and it is a crucial part of the ‘Torino 1911’ project whose main purpose is mapping and virtually reconstructing the 1911 Great Exhibition settled in the Valentino Park in Turin (Italy).

Quality of Reamed Surface Using Serrated Blades as Compared to a Conventional Acetabular Reamer

2013 ◽  
Author(s):  
Annie Levasseur ◽  
Jérémie Ménard ◽  
Victor Songmené ◽  
Julio Fernandes ◽  
Yvan Petit
Keyword(s):  
Experimental Testing ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Numerical Control ◽  
Long Term Stability ◽  
Surface Irregularities ◽  
The Stability ◽  
Acetabular Implant

Background: Hip arthroplasty requires the preparation of the acetabular cavity to allow a proper contact between the bone and the implant. It is essential to allow osseointegration and long-term stability of the implant. The aim of this study was to conduct experimental testing to evaluate the quality of reamed surfaces using a serrated blade acetabular reamer as compared to a conventional rasp reamer. Method of Approach: Reaming tests were performed on a computerized numerical control tools machine at a rotational speed of 250 rpm and 3 different penetration speeds: 0.20 mm/s, 0.55 mm/s and 0.90 mm/s. For each reamer, a complete semi-hemispherical hole was perforated in 7 polyurethane samples. The reamed surfaces were digitized with a three-dimensional high resolution (40 μm) self-positioning laser scanner to carry out a quantitative analysis of the surface quality. Results: Results demonstrated that the cutting edge and the penetration speed influence the quality of the reamed surface. The serrated blade was found to reduce surface irregularities (ranging between 0.19 mm to 0.21 mm for the conventional rasp and between 0.07 mm and 0.12 mm for the serrated blades), and to reduce inaccuracies on the reamed cavity diameter (0.13 mm ± 0.05mm for the rasps and 0.06 mm ± 0.03mm for the serrated blade). Conclusions: The use of such tool by the surgeon may influence the stability of the acetabular implant and reduce the risks of revision surgery.

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