• 제목/요약/키워드: Vision based measurement system

검색결과 216건 처리시간 0.028초

카메라영상에 의한 DGPS-GIS기반 차선변경 지원시스템의 평가 및 신뢰성 검증 (Assessment and Reliability Validation of Lane Departure Assistance System Based on DGPS-GIS Using Camera Vision)

  • 문상찬;이순걸;김민우;주다니
    • 한국자동차공학회논문집
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    • 제22권6호
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    • pp.49-58
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    • 2014
  • This paper proposes a new assessment and reliability validation method of Lane Departure Assistance System based on DGPS-GIS by measuring lanes with camera vision. Assessment of lane departure is performed with yaw speed measurement and determination method for false alarm of ISO 17361 and performance validation is executed after generating departure warning boundary line by considering deviation error of LDAS using DGPS. Distance between the wheel and the lane is obtained through line abstraction using Hough transformation of the lane image with camera vision. Evaluation validation is obtained by comparing this value with the distance obtained with LDAS. The experimental result shows that the error of the extracted distance of the LDAS is within 5 cm. Also it proves performance of LDAS based on DGPS-GIS and assures effectiveness of the proposed validation method for system reliability using camera vision.

바이프리즘 스테레오 시각 센서를 이용한 GMA 용접 비드의 3차원 형상 측정 (Measurement of GMAW Bead Geometry Using Biprism Stereo Vision Sensor)

  • 이지혜;이두현;유중돈
    • Journal of Welding and Joining
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    • 제19권2호
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    • pp.200-207
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    • 2001
  • Three-diemnsional bead profile was measured using the biprism stereo vision sensor in GMAW, which consists of an optical filter, biprism and CCD camera. Since single CCD camera is used, this system has various advantages over the conventional stereo vision system using two cameras such as finding the corresponding points along the horizontal scanline. In this wort, the biprism stereo vision sensor was designed for the GMAW, and the linear calibration method was proposed to determine the prism and camera parameters. Image processing techniques were employed to find the corresponding point along the pool boundary. The ism-intensity contour corresponding to the pool boundary was found in the pixel order and the filter-based matching algorithm was used to refine the corresponding points in the subpixel order. Predicted bead dimensions were in broad agreements with the measured results under the conditions of spray mode and humping bead.

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카메라를 이용한 축계 비틀림 계측 장치 개발 (A Study of the Shaft Power Measuring System Using Cameras)

  • 정정순;김영복;최명수
    • 한국해양공학회지
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    • 제24권4호
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    • pp.72-77
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    • 2010
  • This paper presents a method for measuring the shaft power of a marine main engine. Usually, in traditional systems for measuring shaft power, a strain gauge is used even though it has several disadvantages. First, it is difficult to set up the strain gauge on the shaft and acquire the correct signal for analysis. Second, it is very expensive and complicated. For these reasons, we investigated alternative approaches for measuring shaft power and proposed a new method that uses a vision-based measurement system. For this study, templates for image processing and CCD cameras were installed at the both ends of the shaft. Then, in order for the cameras to capture the images synchronously, we used a trigger mark and a optical sensor. The position of each template between the first and the second camera images were compared to calculate the torsion angle. The proposed measurement system can be installed more easily than traditional measurement systems and is suitable for any shaft because it does not contact the shaft. With this approach, it is possible to measure the shaft power while a ship is operating.

비전 센서 및 딥러닝 기반 선박 접안을 위한 어라운드뷰 모니터링 시스템 (Vision Sensor and Deep Learning-based Around View Monitoring System for Ship Berthing)

  • 김한근;김동훈;박별터;이승목
    • 대한임베디드공학회논문지
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    • 제15권2호
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    • pp.71-78
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    • 2020
  • This paper proposes vision sensors and deep learning-based around view monitoring system for ship berthing. Ship berthing to the port requires precise relative position and relative speed information between the mooring facility and the ship. For ships of Handysize or higher, the vesselships must be docked with the help of pilots and tugboats. In the case of ships handling dangerous cargo, tug boats push the ship and dock it in the port, using the distance and velocity information receiving from the berthing aid system (BAS). However, the existing BAS is very expensive and there is a limit on the size of the vessel that can be measured. Also, there is a limitation that it is difficult to measure distance and speed when there are obstacles near the port. This paper proposes a relative distance and speed estimation system that can be used as a ship berthing assist system. The proposed system is verified by comparing the performance with the existing laser-based distance and speed measurement system through the field tests at the actual port.

역공학에서 센서융합에 의한 효율적인 데이터 획득 (Efficient Digitizing in Reverse Engineering By Sensor Fusion)

  • 박영근;고태조;김희술
    • 한국정밀공학회지
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    • 제18권9호
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    • pp.61-70
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    • 2001
  • This paper introduces a new digitization method with sensor fusion for shape measurement in reverse engineering. Digitization can be classified into contact and non-contact type according to the measurement devices. Important thing in digitization is speed and accuracy. The former is excellent in speed and the latter is good for accuracy. Sensor fusion in digitization intends to incorporate the merits of both types so that the system can be automatized. Firstly, non-contact sensor with vision system acquires coarse 3D point data rapidly. This process is needed to identify and loco]ice the object located at unknown position on the table. Secondly, accurate 3D point data can be automatically obtained using scanning probe based on the previously measured coarse 3D point data. In the research, a great number of measuring points of equi-distance were instructed along the line acquired by the vision system. Finally, the digitized 3D point data are approximated to the rational B-spline surface equation, and the free-formed surface information can be transferred to a commercial CAD/CAM system via IGES translation in order to machine the modeled geometric shape.

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영상 기반 머신툴 프리세터 개발 (Development of a Vision Based Machine Tool Presetter)

  • 정하형;김태연;박진하;유준
    • 한국산업정보학회논문지
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    • 제19권3호
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    • pp.49-56
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    • 2014
  • 툴 프리세터는 수치제어 공작기계용 공구의 테이퍼부를 기준으로 하여 날끝 치수를 사전에 정렬하기 위한 장치로서 여기에는 접촉과 비접촉, 두 가지 방식이 있다. 광학센서 기반 비접촉 방식은 측정의 유연성과 편리함의 이점을 가지고 있다. 본 논문에서는 선형 스케일러와 머신 비전을 도입한 산업용 툴 프리세터 장비 개발을 다룬다. 측정 전에 대상 공구를 기구부에 고정시키고 광학부를 정렬한다. 공구 영상을 취득한 후 제시된 영상처리 알고리즘은선형 스케일러로부터 광학부의 이동 거리를 조합하여 공구의 정밀한 치수를 계산해낸다. 실험 결과, 본 장비의 정밀도가 ${\pm}20um$ 범위내에 있음을 검증하였다.

확장칼만 필터링의 비젼시스템 모델을 이용한 물체 치수 측정에 관한 연구 (A Study on the Estimation of Object's Dimension based on the Vision System Model of Extended Kalman filtering)

  • 장완식;안힘찬;김경석
    • 비파괴검사학회지
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    • 제25권2호
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    • pp.110-116
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    • 2005
  • 비젼시스템을 검사, 물체위치 결정 및 용접 작업등에 실시간 응용하고자할 때 CCD카메라에서 얻어진 많은 데이터를 처리해야 하기 때문에 전산처리 속도를 줄이는 것이 매우 중요하다. 또한, 비젼시스템 모델에 포함되어 있는 매개변수를 추정하는데 있어서 Newton-Raphson 방법 같은 반복적인 기법을 사용하면 많은 전산처리 시간을 필요하게 되어 실시간 응용을 어렵게 한다. 위의 문제점을 해결하기 위해 확장칼만필터링 같은 효율적인 방법이 필요하다. 확장칼만필터링 방법은 CCD카메라로부터 얻어지는 측정데이터의 불확실성을 고려할 뿐만 아니라, 순환적인 처리 기법을 사용하므로 전산처리 속도 향상을 가져온다. 이리하여 본 연구는 비젼시스템 모델에 포함된 카메라 내부 및 외부 매개변수를 설명하는 6개 매개변수 추정과 이를 이용한 물체 치수를 추정하는데 확장칼만필터링 방법을 적용하였다. 마지막으로 개발된 추정기법의 실시간 적용의 타당성을 실험을 통하여 보였다.

비전을 이용한 볼-스터드 검사 시스템에 관한 연구 (A Study on the Vision-Based Inspection System for Ball-Stud)

  • 장영훈;권태종;한창수;문영식
    • 한국정밀공학회지
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    • 제15권12호
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    • pp.7-13
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    • 1998
  • In this paper, an automatic ball-stud inspection system has been developed using the computer-aided vision system. Index table has been used to get the rapid measurement and multi-camera has been used to get the high resolution in physical system. Camera calibration was suggested to perform the reliable inspection. Image processing and data analysis algorithms for ball stud inspection system have been investigated and were performed quickly with high accuracy. As a result, inspection system of a ball stud could be used with a high resolution in real time.

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컴퓨터 시각(視覺)에 의거한 측정기술(測定技術) 및 측정오차(測定誤差)의 분석(分析)과 보정(補正) (Computer Vision Based Measurement, Error Analysis and Calibration)

  • 황헌;이충호
    • Journal of Biosystems Engineering
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    • 제17권1호
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    • pp.65-78
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    • 1992
  • When using a computer vision system for a measurement, the geometrically distorted input image usually restricts the site and size of the measuring window. A geometrically distorted image caused by the image sensing and processing hardware degrades the accuracy of the visual measurement and prohibits the arbitrary selection of the measuring scope. Therefore, an image calibration is inevitable to improve the measuring accuracy. A calibration process is usually done via four steps such as measurement, modeling, parameter estimation, and compensation. In this paper, the efficient error calibration technique of a geometrically distorted input image was developed using a neural network. After calibrating a unit pixel, the distorted image was compensated by training CMLAN(Cerebellar Model Linear Associator Network) without modeling the behavior of any system element. The input/output training pairs for the network was obtained by processing the image of the devised sampled pattern. The generalization property of the network successfully compensates the distortion errors of the untrained arbitrary pixel points on the image space. The error convergence of the trained network with respect to the network control parameters were also presented. The compensated image through the network was then post processed using a simple DDA(Digital Differential Analyzer) to avoid the pixel disconnectivity. The compensation effect was verified using known sized geometric primitives. A way to extract directly a real scaled geometric quantity of the object from the 8-directional chain coding was also devised and coded. Since the developed calibration algorithm does not require any knowledge of modeling system elements and estimating parameters, it can be applied simply to any image processing system. Furthermore, it efficiently enhances the measurement accuracy and allows the arbitrary sizing and locating of the measuring window. The applied and developed algorithms were coded as a menu driven way using MS-C language Ver. 6.0, PC VISION PLUS library functions, and VGA graphic functions.

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영상 기반 변위 계측장치의 현장 적용 성능 평가 (On-site Performance Evaluation of a Vision-based Displacement Measurement System)

  • 조수진;심성한;김은성
    • 한국산학기술학회논문지
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    • 제15권9호
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    • pp.5854-5860
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    • 2014
  • 본 연구에서는 대표적인 토목구조물인 교량에서 영상 기반 변위 계측장치(VDMS)를 이용하여 변위를 측정하고, 고가의 변위측정장비인 LDV와의 비교를 통하여 그 현장 적용 성능을 평가하였다. 본 연구에서 사용한 VDMS는 카메라와 마커, 프레임 그래버, 노트북으로 구성되었으며, 마커를 구조물에 부착하여 그 영상을 촬영하고 평면 호모그래피 기법을 이용하여 마커가 부착된 구조물의 변위를 측정하는 장치이다. 개발된 VDMS의 성능 검증을 위하여 우선 소형 구조물을 이용한 간단한 실내 실험을 수행하였다. 다음으로 실제 철도교량에서 KTX를 다양한 조건으로 주행하고, 그에 의하여 발생한 변위를 VDMS과 LDV를 이용하여 계측한 뒤, 얻어진 두 변위를 비교하여 VDMS의 현장 적용 성능을 평가하였다.