• 제목/요약/키워드: laser measurement

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

  • 이승호;황영철;심석래;정태영
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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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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Relative Navigation with Intermittent Laser-based Measurement for Spacecraft Formation Flying

  • Lee, Jongwoo;Park, Sang-Young;Kang, Dae-Eun
    • Journal of Astronomy and Space Sciences
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    • 제35권3호
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    • pp.163-173
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    • 2018
  • This paper presents relative navigation using intermittent laser-based measurement data for spacecraft flying formation that consist of two spacecrafts; namely, chief and deputy spacecrafts. The measurement data consists of the relative distance measured by a femtosecond laser, and the relative angles between the two spacecrafts. The filtering algorithms used for the relative navigation are the extended Kalman filter (EKF), unscented Kalman filter (UKF), and least squares recursive filter (LSRF). Numerical simulations reveal that the relative navigation performances of the EKF- and UKF-based relative navigation algorithms decrease in accuracy as the measurement outage period increases. However, the relative navigation performance of the UKF-based algorithm is 95 % more accurate than that of the EKF-based algorithm when the measurement outage period is 80 sec. Although the relative navigation performance of the LSRF-based relative navigation algorithm is 94 % and 370 % less accurate than those of the EKF- and UKF-based navigation algorithms, respectively, when the measurement outage period is 5 sec; the navigation error varies within a range of 4 %, even though the measurement outage period is increased. The results of this study can be applied to the design of a relative navigation strategy using the developed algorithms with laser-based measurements for spacecraft formation flying.

레이저 섬광법을 이용한 열확산계수 측정시 오차요인별 분석연구 (A Study on the Error Sources for Thermal Diffusivity Measurement by the Laser Flash Method)

  • 이원식;박상흡
    • Journal of Welding and Joining
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    • 제20권6호
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    • pp.816-822
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    • 2002
  • Laser flash method have been widely used for practical measuring method of thermal diffusivity. And it can be used for measurement of non-conductive materials as well as conductive materials and also for measuring thermal multi-properties. We have analyzed effects of error occurring during measurement of thermal properties in order to enhance measuring accuracy. Also we have studied delay time between measurement starting time with synchronizing signal and laser oscillating time, because it is important that measuring a time to rise temperature of specimen from room temperature to a half of measuring temperature at measuring a thermal diffusivity by laser flash method. We could reduce non-uniform heating error from non-uniform energy distribution by developing 3D uniformizer to eliminate non-uniform heating error. We have measured thermal diffusivities of POCO AXM-5Q1 and Glassy-Carbon which are standard specimen of NIST(USA) and candidate standard specimen of NRLM(japan) respectively for laser flash method. Maximum error fell within 2% for POCO AXM-5Ql gaphite and 2% for Glassy-Carbon. Those results showed error decreasing methods were effective.

원격 레이저 용접 로봇을 위한 형상 측정 센서의 개발과 응용 (Development and Application of a Profile Measurement Sensor for Remote Laser Welding Robots)

  • 김창현;최태용;이주장;서정;박경택;강희신
    • 한국레이저가공학회지
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    • 제12권2호
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    • pp.11-16
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    • 2009
  • A new profile measurement sensor was developed for remote laser welding robots. A stripe laser and a vision camera are used in the profile sensor. A simple sensor guided control scheme using the developed sensor is also introduced. The sensor can be used to guide the welding head in the remote welding application, where the working distance reaches to 450mm. In experiments, the profile measurement and the seam tracking were carried out using the developed sensor.

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나노섬유의 특성분석을 위한 레이저 접촉각 측정기의 효율성 연구 (Feasibility Study of Laser Contact Angle Measurement for Nano-fiber Characterization)

  • 신경인;안선훈;김성훈
    • 한국의류학회지
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    • 제27권5호
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    • pp.554-559
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    • 2003
  • A newly developed contact angle measurement instrument by laser beam projection allows for rapid and direct determination of contact angles. The instrument may have a possibility to characterize newly developed nano-fibers. When the laser beam impinges on an edge of an interface of liquid and solid, projected beam were split across and made two straight lines on a tangent screen. From the result, it could measure the contact angle directly by reading the angle between two split beams. The purpose of this study was to prove reliability and reproducibility of the contact angle measurement instrument by laser beam projection compare to the conventional one by microscope through the comparative experiment and questionnaire. Test samples were selected by consideration of hydrophilic and hydrophobic, such as nylon 6 and polypropylene, respectively. The laser contact angle measurement has accurate, fast and convenient method to measure contact angle, and it can be a unique method to characterize nano-fibers.

구조물 수평변위 계측을 위한 3D Laser scanning과 MEP layout의 비교 분석 (Comparative Analysis of 3D Laser Scanning and MEP Layout for Measurement of Horizontal Displacement of Structures)

  • 심학보;석원균;박순전
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2020년도 가을 학술논문 발표대회
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    • pp.183-183
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    • 2020
  • MEP layout and 3D Laser scanning are widely used equipment for displacement measurement in construction site. In this study, MEP layout and 3D Laser scanning were used to measure the lateral displacement of the same structure, and then the advantages and disadvantages of each were compared and analyzed. In general, it has been shown that MEP layout can save a lot of time compared to 3D Laser scanning. And it was found that the lateral displacement measurement results measured at a distance of 15m were similar to each other.

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차륜/레일 작용력 측정을 위한 레이저기술과 스트레인게이지 응용기술 비교 (Comparison of laser technology & strain gauge application technology for measurement of interaction force between wheel and rail)

  • 함영삼;정우진;서정원
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.219-223
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    • 2004
  • Korea Railroad Research Institute(KRRI) propelled sensing and measurement techniques development for measure of Lateral Force and Vertical Force With Italy to international cooperation research project for laser technology for measurement of wheel/rail interaction force. In this paper, we compared the laser technology for measurement of wheel/rail interaction force with the existing method. And then, we suggests interaction force measurement system procedure of hereafter.

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Fabry-Perot 레이저의 자기궤환 레이저 발진을 이용한 색분산 측정법 (Dispersion measurement technique based on a self-seeding laser oscillation of a Fabry-Perot laser)

  • 윤기홍;송재원;김현덕
    • 한국광학회지
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    • 제15권2호
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    • pp.104-108
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    • 2004
  • 폐경로를 통한 Fabry-Perot 레이저의 자기궤환 레이저 발진(self-seeding laser oscillation)을 이용하여 구조가 간단하고 경제적인 색분산(chromatic dispersion) 측정법을 제안하였다. 저가의 Fabry-Perot 레이저를 이용하여 광펄스들을 생성하고, 광섬유를 통해 전송되는 광펄스들 사이의 군속도 차(group delay difference)를 Fabry-Perot 레이저의 자기궤환 발진 현상을 통해 감지함으로써 광섬유의 색분산계수를 측정할 수 있도록 하였다. 제안된 측정법에 따라 구현된 측정 장치는 고가의 상용 계측기와 비슷한 수준의 색분산계수 측정 정확도를 제공하고, 재현성은 0.5%보다 좋음을 실험적으로 검증하였다.

Calibration of the depth measurement system with a laser pointer, a camera and a plain mirror

  • Kim, Hyong-Suk;Lin, Chun-Shin;Gim, Seong-Chan;Chae, Hee-Sung
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1994-1998
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    • 2005
  • Characteristic analysis of the depth measurement system with a laser, a camera and a rotating mirror has been done and the parameter calibration technique for it has been proposed. In the proposed depth measurement system, the laser beam is reflected to the object by the rotating mirror and again the position of the laser beam is observed through the same mirror by the camera. The depth of the object pointed by the laser beam is computed depending on the pixel position on the CCD. There involved several number of internal and external parameters such as inter-pixel distance, focal length, position and orientation of the system components in the depth measurement error. In this paper, it is shown through the error sensitivity analysis of the parameters that the most important parameters in the sense of error sources are the angle of the laser beam and the inter pixel distance. The calibration techniques to minimize the effect of such major parameters are proposed.

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Pitch Measurement of 150 nm 1D-grating Standards Using an Nano-metrological Atomic Force Microscope

  • Jonghan Jin;Ichiko Misumi;Satoshi Gonda;Tomizo Kurosawa
    • International Journal of Precision Engineering and Manufacturing
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    • 제5권3호
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    • pp.19-25
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    • 2004
  • Pitch measurements of 150 nm one-dimensional grating standards were carried out using a contact mode atomic force microscopy with a high resolution three-axis laser interferometer. This measurement technique was named as the 'nano-metrological AFM'. In the nano-metrological AFM, three laser interferometers were aligned precisely to the end of an AFM tip. Laser sources of the three-axis laser interferometer in the nano-metrological AFM were calibrated with an I$_2$ stabilized He-Ne laser at a wavelength of 633 nm. Therefore, the Abbe error was minimized and the result of the pitch measurement using the nano-metrological AFM could be used to directly measure the length standard. The uncertainty in the pitch measurement was estimated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM). The primary source of uncertainty in the pitch-measurements was derived from the repeatability of the pitch-measurements, and its value was about 0.186 nm. The average pitch value was 146.65 nm and the combined standard uncertainty was less than 0.262 nm. It is suggested that the metrological AFM is a useful tool for the nano-metrological standard calibration.