Laser Scanners

2017 ◽  
pp. 108-145 ◽  
Author(s):  
Lars Lindner
Keyword(s):  
Laser Beam ◽  
Vision System ◽  
Laser Scanner ◽  
Image Sensors ◽  
Measurement Methods ◽  
Coordinate Measurement ◽  
Technical Vision ◽  
Laser Scanners ◽  
Engineering Institute

The presented book chapter provides an overview and detailed description about actual used laser scanner systems. It explains and compares the mainly used coordinate measurement methods, like Time-of-flight, Phasing and Triangulation and Imaging. A Technical Vision System, developed by the engineering institute at the Autonomous University Baja California (UABC) is presented. The mostly used mechanical principles to position a laser beam in a field of view are described and which mechanical actuators are applied. The reflected laser beam gets measured by light sensors or image sensors, which are explained and some principle measuring circuits are provided. The received measuring data gets post-processed by different algorithm or principles, which close the chapter.

scholarly journals ON PRACTICAL ACCURACY ASPECTS OF UNMANNED AERIAL VEHICLES EQUIPPED WITH SURVEY GRADE LASER SCANNERS

2020 ◽  
Vol XLIII-B1-2020 ◽  
pp. 343-348
Author(s):  
K. Nakano ◽  
Y. Tanaka ◽  
H. Suzuki ◽  
K. Hayakawa ◽  
M. Kurodai
Keyword(s):  
Unmanned Aerial Vehicles ◽  
High Performance ◽  
Laser Scanner ◽  
Image Sensors ◽  
Measuring Devices ◽  
Aerial Vehicles ◽  
Laser Scanners ◽  
Surface Models ◽  
Reconstruction Software ◽  
Practical Accuracy

Abstract. Unmanned aerial vehicles (UAVs) equipped with image sensors, which have been widely used in various fields such as construction, agriculture, and disaster management, can obtain images at the millimeter to decimeter scale. Useful tools that produce realistic surface models using 3D reconstruction software based on computer vision technologies are generally used to produce datasets from acquired images using UAVs. However, it is difficult to obtain the feature points from surfaces with limited texture, such as new asphalt or concrete, or detect the ground in areas such as forests, which are commonly concealed by vegetation. A promising method to address such issues is the use of UAV-equipped laser scanners. Recently, low and high performance products that use direct georeferencing devices integrated with laser scanners have been available. Moreover, there have been numerous reports regarding the various applications of UAVs equipped with laser scanners; however, these reports only discuss UAVs as measuring devices. Therefore, to understand the functioning of UAVs equipped with laser scanners, we investigated the theoretical accuracy of the survey grade laser scanner unit from the viewpoint of photogrammetry. We evaluated the performance of the VUX-1HA laser scanner equipped on a Skymatix X-LS1 UAV at a construction site. We presented the theoretical values obtained using the observation equations and results of the accuracy aspects of the acquired data in terms of height.

Use of Laser Scanner for Digital Surveying of the Sarnicli Inn and the Byzantine Cistern Underneath

2017 ◽  
pp. 227-254
Author(s):  
Gülhan Benli ◽  
Eylem Görmüş Ekizce
Keyword(s):  
Cultural Heritage ◽  
Protected Areas ◽  
Laser Scanning ◽  
Laser Scanner ◽  
3D Scanning ◽  
Measurement Methods ◽  
Advanced Technology ◽  
Laser Scanners ◽  
Close Range ◽  
Photogrammetric Measurement

Measurement methods including traditional measurement methods, topographic and photogrammetric measurement methods, measurements via laser scanning devices and aerial photogrammetric measurement methods obtained using model airplane or model helicopters are used in documentation of the cultural heritage and protected areas in our country. Although data obtained by Aerial Lidar technology accepted as advanced technology over the past decade, enables faster data comparing to others as data obtained by terrestrial laser scanners provide millimetre level accuracy close-range scanning methods are preferred in architectural facades scanning during the process of surveying of a single building. Inclusion process of a Byzantine cistern in Istanbul, Turkey, which was undiscovered for centuries, in our cultural heritage as well as surveying stages of the cistern along with the inn structure built over, using 3D scanning technology shall be described within this study.

Advances in Laser Scanners

2021 ◽  
pp. 37-70
Author(s):  
Lars Lindner ◽  
Oleg Sergiyenko ◽  
Moisés Rivas-Lopez ◽  
Wendy Flores-Fuentes ◽  
Julio C. Rodríguez-Quiñonez ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Vision System ◽  
Step Response ◽  
New Approach ◽  
Dead Zones ◽  
Dc Motors ◽  
Technical Vision ◽  
Laser Scanners ◽  
Principal Parts ◽  
Further Development

One focus of present chapter is defined by the further development of the technical vision system (TVS). The TVS mainly contains two principal parts, the positioning laser (PL) and the scanning aperture (SA), which implement the optomechanical function of the dynamic triangulation. Previous versions of the TVS uses stepping motors to position the laser beam, which leads to a discrete field of view (FOV). Using stepping motors, inevitable dead zones arise, where 3D coordinates cannot be detected. One advance of this TVS is defined by the substitution of these discrete actuators by DC motors to eliminate dead zones and to perform a continuous laser scan in the TVS FOV. Previous versions of this TVS also uses a constant step response as closed-loop input. Thereby the chapter describes a new approach to position the TVS laser ray in the FOV, using a trapezoidal velocity profile as trajectory.

Use of Laser Scanner for Digital Surveying of the Sarnicli Inn and the Byzantine Cistern Underneath

2019 ◽  
pp. 275-303
Author(s):  
Gülhan Benli ◽  
Eylem Görmüş Ekizce
Keyword(s):  
Cultural Heritage ◽  
Protected Areas ◽  
Laser Scanning ◽  
Laser Scanner ◽  
3D Scanning ◽  
Measurement Methods ◽  
Advanced Technology ◽  
Laser Scanners ◽  
Close Range ◽  
Photogrammetric Measurement

Measurement methods including traditional measurement methods, topographic and photogrammetric measurement methods, measurements via laser scanning devices and aerial photogrammetric measurement methods obtained using model airplane or model helicopters are used in documentation of the cultural heritage and protected areas in our country. Although data obtained by Aerial Lidar technology accepted as advanced technology over the past decade, enables faster data comparing to others as data obtained by terrestrial laser scanners provide millimetre level accuracy close-range scanning methods are preferred in architectural facades scanning during the process of surveying of a single building. Inclusion process of a Byzantine cistern in Istanbul, Turkey, which was undiscovered for centuries, in our cultural heritage as well as surveying stages of the cistern along with the inn structure built over, using 3D scanning technology shall be described within this study.

Mobile Robot Path Planning Using Continuous Laser Scanning

2019 ◽  
pp. 338-372 ◽  
Author(s):  
Mykhailo Ivanov ◽  
Lars Lindner ◽  
Oleg Sergiyenko ◽  
Julio Cesar Rodríguez-Quiñonez ◽  
Wendy Flores-Fuentes ◽  
...  
Keyword(s):  
Path Planning ◽  
Mobile Robot ◽  
Laser Scanning ◽  
Vision System ◽  
Robot Path Planning ◽  
Continuous Laser ◽  
Technical Vision ◽  
Road Maps ◽  
Robot Path

The main object of this book chapter is an introduction and presentation of mobile robot path planning using continuous laser scanning, which has significant advantages compared with discrete laser scanning. A general introduction to laser scanning systems is given, whereby a novel technical vision system (TVS) using the dynamic triangulation measurement method for 3D coordinate determination is found suitable for accomplishing this task of mobile robot path planning. Furthermore, methods and algorithms for mobile robot road maps and path planning are presented and compared.

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 LiDAR-Based Glass Detection for Improved Occupancy Grid Mapping

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2263
Author(s):  
Haileleol Tibebu ◽  
Jamie Roche ◽  
Varuna De Silva ◽  
Ahmet Kondoz
Keyword(s):  
Laser Scanner ◽  
Point Clouds ◽  
Light Detection And Ranging ◽  
Test Results ◽  
New Approach ◽  
Occupancy Grid ◽  
Laser Scanners ◽  
Novel Method ◽  
Occupancy Grid Mapping ◽  
Cartesian Coordinate

Creating an accurate awareness of the environment using laser scanners is a major challenge in robotics and auto industries. LiDAR (light detection and ranging) is a powerful laser scanner that provides a detailed map of the environment. However, efficient and accurate mapping of the environment is yet to be obtained, as most modern environments contain glass, which is invisible to LiDAR. In this paper, a method to effectively detect and localise glass using LiDAR sensors is proposed. This new approach is based on the variation of range measurements between neighbouring point clouds, using a two-step filter. The first filter examines the change in the standard deviation of neighbouring clouds. The second filter uses a change in distance and intensity between neighbouring pules to refine the results from the first filter and estimate the glass profile width before updating the cartesian coordinate and range measurement by the instrument. Test results demonstrate the detection and localisation of glass and the elimination of errors caused by glass in occupancy grid maps. This novel method detects frameless glass from a long range and does not depend on intensity peak with an accuracy of 96.2%.

scholarly journals Metric Accuracy Evaluation of Dense Matching Algorithms in Archeological Applications

2011 ◽  
Vol 6 ◽  
pp. 275-282 ◽  
Author(s):  
C. Re ◽  
S. Robson ◽  
R. Roncella ◽  
M Hess
Keyword(s):  
Laser Scanner ◽  
Medium Size ◽  
Accuracy Evaluation ◽  
Software Packages ◽  
Dense Matching ◽  
Laser Scanners ◽  
Surface Models ◽  
University College London ◽  
Archaeological Artifacts ◽  
Archaeological Objects

In the cultural heritage field the recording and documentation of small and medium size objects with very detailed Digital Surface Models (DSM) is readily possible by through the use of high resolution and high precision triangulation laser scanners. 3D surface recording of archaeological objects can be easily achieved in museums; however, this type of record can be quite expensive. In many cases photogrammetry can provide a viable alternative for the generation of DSMs. The photogrammetric procedure has some benefits with respect to laser survey. The research described in this paper sets out to verify the reconstruction accuracy of DSMs of some archaeological artifacts obtained by photogrammetric survey. The experimentation has been carried out on some objects preserved in the Petrie Museum of Egyptian Archaeology at University College London (UCL). DSMs produced by two photogrammetric software packages are compared with the digital 3D model obtained by a state of the art triangulation color laser scanner. Intercomparison between the generated DSM has allowed an evaluation of metric accuracy of the photogrammetric approach applied to archaeological documentation and of precision performances of the two software packages.

scholarly journals Research on laser stripe characteristics and center extraction algorithm for desktop laser scanner

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Xiaoquan Shi ◽  
Yazhou Sun ◽  
Haitao Liu ◽  
Linqi Bai ◽  
Chonghao Lin
Keyword(s):  
Laser Scanner ◽  
Bright Spot ◽  
Distribution Characteristics ◽  
Ambient Light ◽  
Centroid Method ◽  
Laser Stripe ◽  
Wide Range ◽  
Laser Scanners ◽  
Extraction Algorithm ◽  
Large Width

AbstractThis study presents laser stripe center extraction algorithm for desktop-level 3D laser scanners. The laser stripe center extraction accuracy is an important factor affecting 3D scanning result. Desktop-level devices should have adaptability of a wide range of scanning objects. In this paper, laser stripe energy distribution characteristics with different laser stripe width, ambient light, materials and colors are obtained by experiments. Experiment results show that waveforms of bright spot, low brightness stripe and stripe with large width are complex or easily disturbed, so the center extraction algorithm of them are studied. The extraction effects of extremum method, gradient method and gray centroid method under different conditions are compared. Based on traditional grayscale value, a weighted grayscale value is proposed to extract laser stripe center. Standard deviations of extracted pixel position and fitting pixel position are calculated by different method with different weighted grayscale value. For different conditions, especially for different ambient light intensity, weight matrix plays an important role to extraction result.

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