• Title/Summary/Keyword: Active Camera

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A study on the theoretical minimum resolution of the laser range finder (레이저 거리계의 이론적 최소 분해능에 관한 연구)

  • 차영엽;권대갑
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.644-647
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    • 1996
  • In this study the theoretical minimum resolution analysis of an active vision system using laser range finder is performed for surrounding recognition and 3D data acquisition in unknown environment. The laser range finder consists of a slitted laser beam generator, a scanning mechanism, CCD camera, and a signal processing unit. A laser beam from laser source is slitted by a set of cylindrical lenses and the slitted laser beam is emitted up and down and rotates by the scanning mechanism. The image of laser beam reflected on the surface of an object is engraved on the CCD array. In the result, the resolution of range data in laser range finder is depend on distance between lens center of CCD camera and light emitter, view and beam angles, and parameters of CCD camera.

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Disparity compensation for vergence control of active stereo camera (배경시차 보정을 이용한 스테레오 시각장치의 주시각제어)

  • 박순용;이용범;진성일
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.9
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    • pp.67-76
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    • 1997
  • This ppaer describes the development of the stereo camera system(KASS-1) and the control of the vergence of the stereo camera to fix a gaze on a moving object in real-time using a stereo disparity. The motion energy and the stereo disparity of a moving object from the stereo image are used to control the vergence of stereo camera to keep stereo disparity constant. The disparity from the rotating stereo camera is introduced not only from the moving object but also from the background. In this paper, the background disparity error due to the vergence control of the stereo camera is eliminated by compensation algoithm, and the vergence of steereo camera system can be controlled continuously using the disparity of a moving object only.

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An Efficient Algorithm for 3-D Range Measurement using Disparity of Stereoscopic Camera (스테레오 카메라의 양안 시차를 이용한 거리 계측의 고속 연산 알고리즘)

  • 김재한
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.6
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    • pp.1163-1168
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    • 2001
  • The ranging systems measure range data in three-dimensional coordinate from target surface. These non-contact remote ranging systems is widely used in various automation applications, including military equipment, construction field, navigation, inspection, assembly, and robot vision. The active ranging systems using time of flight technique or light pattern illumination technique are complex and expensive, the passive systems based on stereo or focusing principle are time-consuming. The proposed algorithm, that is based on cross correlation of projection profile of vertical edge, provides advantages of fast and simple operation in the range acquisition. The results of experiment show the effectiveness of the proposed algorithm.

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Tracking and Capturing a Moving Object Using Active Camera Mounted on a Mobile Robot (이동로봇에 장착된 능동 카메라를 이용한 이동물체의 추적과 포획)

  • Park, Jin-U;Park, Jae-Han;Yun, Gyeong-Sik;Lee, Jang-Myeong
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.9
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    • pp.741-748
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    • 2001
  • In this paper, we propose a method of tracking and capturing a moving object by a mobile robot. The position of the moving object is acquired from the relation through color-based image information from a 2-DOF active camera mounted on the mobile robot. The direction and rotational angular velocity of the moving object are estimated using a state estimator. A Kalman fiber is used as the state estimator for taking characteristics of robustness against noises and uncertainties included in the input data. After estimating the trajectory of the moving object, we decide on the optimal trajectory and plan the motion of the mobile robot to capture the target object within the shortest distance and time. The effectiveness of the proposed method is demonstrated by the simulations and experiments.

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Moving Object Tracking in Active Camera Environment Based on Bayes Decision Theory (Bayes 결정이론에 기반을 둔 능동카메라 환경에서의 이동 물체의 검출 및 추적)

  • 배수현;강문기
    • Journal of Broadcast Engineering
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    • v.4 no.1
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    • pp.22-31
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    • 1999
  • Moving object tracking improves the efficiency and qualification for observation system, broadcasting system, video conference, etc. This paper propcses an improved Bayes decision method for detecting and tracking moving objects in active camera environment. The Bayes decision based tracking approach finds the region of moving objects by analyzing the image sequences statistically. The propcsed algorithm regenerates the probability density function to accord with moving objects and background for active camera. Experimental results show that the algorithm is accurate. reliable and noise resistant. The result is compared with those of the conventional methods.

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Using Contour Matching for Omnidirectional Camera Calibration (투영곡선의 자동정합을 이용한 전방향 카메라 보정)

  • Hwang, Yong-Ho;Hong, Hyun-Ki
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.45 no.6
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    • pp.125-132
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    • 2008
  • Omnidirectional camera system with a wide view angle is widely used in surveillance and robotics areas. In general, most of previous studies on estimating a projection model and the extrinsic parameters from the omnidirectional images assume corresponding points previously established among views. This paper presents a novel omnidirectional camera calibration based on automatic contour matching. In the first place, we estimate the initial parameters including translation and rotations by using the epipolar constraint from the matched feature points. After choosing the interested points adjacent to more than two contours, we establish a precise correspondence among the connected contours by using the initial parameters and the active matching windows. The extrinsic parameters of the omnidirectional camera are estimated minimizing the angular errors of the epipolar plane of endpoints and the inverse projected 3D vectors. Experimental results on synthetic and real images demonstrate that the proposed algorithm obtains more precise camera parameters than the previous method.

The General Analysis of an Active Stereo Vision with Hand-Eye Calibration (핸드-아이 보정과 능동 스테레오 비젼의 일반적 해석)

  • Kim, Jin Dae;Lee, Jae Won;Sin, Chan Bae
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.5
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    • pp.83-83
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    • 2004
  • The analysis of relative pose(position and rotation) between stereo cameras is very important to determine the solution that provides three-dimensional information for an arbitrary moving target with respect to robot-end. In the space of free camera-model, the rotational parameters act on non-linear factors acquiring a kinematical solution. In this paper the general solution of active stereo that gives a three-dimensional pose of moving object is presented. The focus is to achieve a derivation of linear equation between a robot′s end and active stereo cameras. The equation is consistently derived from the vector of quaternion space. The calibration of cameras is also derived in this space. Computer simulation and the results of error-sensitivity demonstrate the successful operation of the solution. The suggested solution can also be applied to the more complex real time tracking and quite general and are applicable in various stereo fields.

The General Analysis of an Active Stereo Vision with Hand-Eye Calibration (핸드-아이 보정과 능동 스테레오 비젼의 일반적 해석)

  • 김진대;이재원;신찬배
    • Journal of the Korean Society for Precision Engineering
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    • v.21 no.5
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    • pp.89-90
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    • 2004
  • The analysis of relative pose(position and rotation) between stereo cameras is very important to determine the solution that provides three-dimensional information for an arbitrary moving target with respect to robot-end. In the space of free camera-model, the rotational parameters act on non-linear factors acquiring a kinematical solution. In this paper the general solution of active stereo that gives a three-dimensional pose of moving object is presented. The focus is to achieve a derivation of linear equation between a robot's end and active stereo cameras. The equation is consistently derived from the vector of quaternion space. The calibration of cameras is also derived in this space. Computer simulation and the results of error-sensitivity demonstrate the successful operation of the solution. The suggested solution can also be applied to the more complex real time tracking and quite general and are applicable in various stereo fields.

An Exact 3D Data Extraction Algorithm For Active Range Sensor using Laser Slit (레이저 슬릿을 사용하는 능동거리 센서의 정확한 3D 데이터 추출 알고리즘)

  • Cha, Y.Y.;Gweon, D.G.
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.8
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    • pp.73-85
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    • 1995
  • The sensor system to measure the distance precisely from the center of the sensor system to the obstacle is needed to recognize the surrounding environments, and the sensor system is to be calibrated thoroughly to get the range information exactly. This study covers the calibration of the active range sensor which consists of camera and laser slit emitting device, and provides the equations to get the 3D range data. This can be possible by obtaining the extrinsic parameters of laser slit emitting device through image processing the slits measured during the constant distance intervals and the intrinsic parameters from the calibration of camera. The 3D range data equation derived from the simple geometric assumptions is proved to be applicable to the general cases using the calibration parameters. Also the exact 3D range data were obtained to the object from the real experiment.

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Analysis of Visible Light Communication Module Degraded by High Dose-Rate Gamma Irradiation using Thermal Infrared Image (적외선 열영상을 이용한 가시광 통신모듈의 고선량 감마선조사에 따른 열화 분석)

  • Cho, Jai-Wan;Hong, Seok-Boong;Koo, In-Soo
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.12
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    • pp.1203-1209
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    • 2011
  • In this paper, the degradation evaluation method of VLC (Visible Light Communication) wireless module after high dose rate gamma-ray irradiation using the thermal infrared camera is proposed. First, the heating characteristics of the active devices embedded in the VLC wireless module during the condition of normal operation is monitored by thermal infrared camera. By the image processing technique, the trends of the intensity of the heat emitted by the active devices are calculated and stored. The feature of the blob area including the area of the active devices in the thermal infrared image is extracted and stored. The feature used in this paper is the mean value of the gray levels in the blob area. The same VLC module has been gamma irradiated at the dose rate of about 4.0 kGy/h during 72 hours up to a total dose of 288 kGy. And then, the heating characteristics of the active devices embedded in the VLC wireless module after high dose gamma ray irradiation is observed by thermal infrared camera. The high dose gamma-ray induced degradation of the active devices embedded in the VLC module was evaluated by comparing the mean value of the blob area to the one of the same blob area of the VLC module before the gamma ray irradiation.