• Title, Summary, Keyword: Laser Scanner

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A Study on Precision Measurement of Rock Joint Using 3D-Laser Scanner (3D-Laser scanner를 이용한 암반 절리의 정밀측정에 관한 연구)

  • 이승호;황영철;김세현;심석래;정태영
    • Explosives and Blasting
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    • v.22 no.3
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    • pp.103-111
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    • 2004
  • The existing methods that can be adopted for measuring joints involve either to use borehole or photogrammetry. Due to restricted space, acquisition of data in limited area, and measurement errors, above methods have limitations acquiring the objective and correct results. To get over defects of existing joint measurement methods, joints have been measured using 3D-Laser scanner with accuracy and efficiency. This research aims to investigate an accuracy and applicabiliy of 3D-Laser scanner for measuring rock slope joints. Measurement of rock slope joints has been executed using 3D-Laser scanner & clinometer and then, results from both methods are compared. Results from both methods indicate that they show nearly equal features for joint distributions and numbers of joint information obtained by 3D-Laser scanner are much more than ones measured using clinomer. Therefore, 3D-Laser scanner turns out to be very effective by the fact that it contributes to reduce investigation costs & periods, objectify data from rock slope joints.

LAND SLIDE DISPLACEMENT DETECTION USING TIME SERIES DIGITAL SURFACE MODEL ACQUIRED BY A TERRESTRIAL LASER SCANNER

  • Jeong, Jong-Hyeok;Takagi, Masataka
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.567-569
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    • 2006
  • Recently, the terrestrial laser scanner is considered as useful measurement equipment for acquiring a three-dimensional data. In this study, a terrestrial laser scanner which has +/- 2.5cm accuracy is examined whether the terrestrial laser scanner is reliable to present the tendency of landslide movement. The test area is covered by protection blocks, and they are being moved by landslide movement. Landslide movement was detected by measuring the movement of protection blocks. Totally three scenes of test area were acquired during 2004 and 2006. The three scenes of the protection blocks were registered in global coordinate system, then the landslide movement was investigated. The landslide movement detected in the three scenes was evaluated by comparing with landslide movement measured by a total station. Although the measurement accuracy of landslide using the terrestrial laser scanner was worse than the total station, the scanning data showed the tendency of landslide movement of the test area.

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On-road Vehicle Tracking using Laser Scanner with Multiple Hypothesis Assumption

  • Ryu, Kyung-Jin;Park, Seong-Keun;Hwang, Jae-Pil;Kim, Eun-Tai;Park, Mignon
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.9 no.3
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    • pp.232-237
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    • 2009
  • Active safety vehicle devices are getting more attention recently. To prevent traffic accidents, the environment in front and even around the vehicle must be checked and monitored. In the present applications, mainly camera and radar based systems are used as sensing devices. Laser scanner, one of the sensing devices, has the advantage of obtaining accurate measurement of the distance and the geometric information about the objects in the field of view of the laser scanner. However, there is a problem that detecting object occluded by a foreground one is difficult. In this paper, criterions are proposed to manage this problem. Simulation is conducted by vehicle mounted the laser scanner and multiple-hypothesis algorithm tracks the candidate objects. We compare the running times as multi-hypothesis algorithm parameter varies.

Obstacle Detection and Classification Algorithm using a Laser Scanner (레이저 스캐너를 이용한 장애물 탐색 및 분리 알고리즘 개발)

  • Lee, Gi-Roung;Hong, Suk-Kyo;Chwa, Dong-Kyoung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.4
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    • pp.677-685
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    • 2008
  • This paper proposes algorithm for the obstacle detection and classification using a single laser scanner. In a measurement data from a laser scanner, there exist points with large differential value called singular points, which can be used to obtain the boundary of an obstacle such that obstacle information can be analyzed. On the other hand, measurement data include a lot of measurement error, which makes it difficult to analyze the accurate obstacle information. To solve this problem, the least square estimation algorithm is used to obtain the accurate information using a single laser scanner, by compensation for the measurement error. This algorithm can be used for the effective obstacle avoidance of mobile robots, and the experimental results are included to demonstrate the effectiveness of the propose algorithm.

High-Speed Femtosecond Laser Micromachining with a Scanner (스캐너를 이용한 고속 펨토초 레이저 가공 기술)

  • Sohn, Ik-Bu;Choi, Sung-Chul;Noh, Young-Chul;Ko, Do-Kyeong;Lee, Jong-Min
    • Journal of Korean Society of Laser Processing
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    • v.9 no.2
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    • pp.11-15
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    • 2006
  • We report experimental results on the high-speed micromachining using a femtosecond laser (800 nm, 130 fs, 1kHz) and galvanometer scanner system (Raylase, Germany). Periodic hole drilling of silicon and glass with the scan speed of 1-20 mm/s is demonstrated. Finally, we demonstrate the utility of the femtosecond laser application to ITO patterning by using a high-speed femtosecond laser scanner system.

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Pattern Recognition Using 2D Laser Scanner Shaking (2D 레이저 스캐너 흔듦을 이용한 패턴인식)

  • Kwon, Seongkyung;Jo, Haejoon;Yoon, Jinyoung;Lee, Hoseung;Lee, Jaechun;Kwak, Sungwoo;Choi, Haewoon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.22 no.4
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    • pp.138-144
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    • 2014
  • Now, Autonomous unmanned vehicle has become an issue in next generation technology. 2D Laser scanner as the distance measurement sensor is used. 2D Laser scanner detects the distance of 80m, measured angle is -5 to 185 degree. Laser scanner detects only the plane, but using motor swings. As a result, traffic signs detect and analyze patterns. Traffic signs when driving at low speed, shape of the detected pattern is very similar. By shaking the laser scanner, traffic signs and other obstacles became clear distinction.

Development of Underwater Laser Scanner with Efficient and Flexible Installation for Unmanned Underwater Vehicle (무인잠수정을 위한 효과적이고 유연한 설치 성능을 지닌 수중 레이저스캐너 개발)

  • Lee, Yeongjun;Lee, Yoongeon;Chae, Junbo;Choi, Hyun-Taek;Yeu, Tae-Kyeong
    • Journal of Ocean Engineering and Technology
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    • v.32 no.6
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    • pp.511-517
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    • 2018
  • This paper proposes a vision-based underwater laser scanner with separate structures for an underwater camera and a line laser projector. Because the two devices can be adaptively placed regardless of the features of the unmanned underwater vehicle (UUV), the scanner has significant advantages in relation to its availability and flexibility. Position calibration between the underwater camera and laser projector guarantees a 3D measuring performance with high accuracy. To verify the proposed underwater laser scanner, a test-bed system was manufactured, which consisted of the laser projector, camera, Pan&Tilt, and Attitude and Heading Reference System (AHRS). A camera-laser calibration test and simple 3D reconstruction test were performed in a water tank and the experimental results are reported.

Measurement of Rock Slope Joint using 3D Image Processing (3차원 영상처리를 이용한 암반 사면의 절리 측정에 관한 연구)

  • Lee, Seung-Ho;Hwang, Jeong-Cheol;Sim, Seok-Rae;Jeong, Tae-Young
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.854-861
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    • 2005
  • Studied accuracy and practical use possibility of joint measurement that using 3D laser scanner to rock slope. Measured joint of Rock slope and comparison applied 3 dimension laser scanner and clinometer. 3D laser scanning system preserves on computer calculating to 3 dimension coordinate scaning laser to object. and according to laser measurement method of interior, produce correct vector value from charge-coupled device(CCD) or laser reciver and telegram register and time measuring equipment. Create of object x, y, z point coordinates to 3 dimension space of computer. Such 3 dimension point datum (Point Clouds) forms relocate position informations that exist to practical space to computer space. Practical numerical values related between each other. Compared joint distribution and direction that measured by laser scanner and clinometer. By the result, Distribution of joint projected almost equally. Could get more joint datas by measurement of 3 dimension scanner than measured by clinometer. Therefore, There is effect that objectification of rock slope investigation data, shortening of investigation periods, investigation reduction of cost. could know that it is very effective method in joint measuring.

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The construction management of tunnel using 3D laser scanner (3차원 레이저 스캐너를 활용한 터널 시공관리)

  • Lee, Kang-Hyun;Heo, In-Wook;Kim, Do-Hoon;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.13 no.3
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    • pp.159-176
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    • 2011
  • A 3D laser scanner is widely used in various fields such as games, movies, medicines, art, design, etc. Many studies for utilizing the 3D laser scanner in the fields of civil engineering have also been carried out, for example, for systematically managing tunnel and/or bridge construction. However, since a software which is directly applicable to Korean construction system does not exist, the amount of data obtained from existing the 3D laser scanner is too much to handle in a systematic way. Therefore, in this paper, a new data processing technique was established which can rapidly and effectively treat the 3D laser scanning data. Moreover, a software that can systematically manage the tunnel construction was developed. The developed software can assess the construction quality of tunnel excavation such as under-break, over-break, cracks, leakage and efflorescence, etc. A 3D laser scanner and the developed software was applied to an in-situ tunnelling site, and verified usefulness of the 3D laser scanner. The developed software may be useful for tunnel maintenance as well as for systematic management of tunnel construction.

Evaluation of Geometric Error Sources for Terrestrial Laser Scanner

  • Lee, Ji Sang;Hong, Seung Hwan;Park, Il Suk;Cho, Hyoung Sig;Sohn, Hong Gyoo
    • Journal of Korean Society for Geospatial Information System
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    • v.24 no.2
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    • pp.79-87
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    • 2016
  • As 3D geospatial information is demanded, terrestrial laser scanners which can obtain 3D model of objects have been applied in various fields such as Building Information Modeling (BIM), structural analysis, and disaster management. To acquire precise data, performance evaluation of a terrestrial laser scanner must be conducted. While existing 3D surveying equipment like a total station has a standard method for performance evaluation, a terrestrial laser scanner evaluation technique for users is not established. This paper categorizes and analyzes error sources which generally occur in terrestrial laser scanning. In addition to the prior researches about categorizing error sources of terrestrial Laser scanning, this paper evaluates the error sources by the actual field tests for the smooth in-situ applications.The error factors in terrestrial laser scanning are categorized into interior error caused by mechanical errors in a terrestrial laser scanner and exterior errors affected by scanning geometry and target property. Each error sources were evaluated by simulation and actual experiments. The 3D coordinates of observed target can be distortedby the biases in distance and rotation measurement in scanning system. In particular, the exterior factors caused significant geometric errors in observed point cloud. The noise points can be generated by steep incidence angle, mixed-pixel and crosstalk. In using terrestrial laser scanner, elaborate scanning plan and proper post processing are required to obtain valid and accurate 3D spatial information.