Camera Self-Calibration from Two Ellipse Contours in Pipes

  • Jeong, Kyung-Min (Nuclear Robotics Lab., Korea Atomic Energy Research Institute) ;
  • Seo, Yong-Chil (Nuclear Robotics Lab., Korea Atomic Energy Research Institute) ;
  • Choi, Young-Soo (Nuclear Robotics Lab., Korea Atomic Energy Research Institute) ;
  • Cho, Jai-Wan (Nuclear Robotics Lab., Korea Atomic Energy Research Institute) ;
  • Lee, Sung-Uk (Nuclear Robotics Lab., Korea Atomic Energy Research Institute) ;
  • Kim, Seung-Ho (Nuclear Robotics Lab., Korea Atomic Energy Research Institute)
  • Published : 2004.08.25

Abstract

A tele-operated robot should be used to maintain and inspect nuclear power plants to reduce the radiation exposure to the human operators. During an overhaul of the nuclear power plants in Korea, a ROV(Remotely Operated Vehicle) may enter a cold-leg connected to the reactor to examine the state of the thermal sleeve and it's position in the safety injection nozzle. To measure the positions of the thermal sleeve or scratches from the video images captured during the examination, the camera parameters should be identified. However, the focal length of the CCD camera could be increased to a close up of the target and the aspect ratio and the center of the image could also be varied with capturing devices. So, it is desired to self-calibrated the intrinsic parameters of the camera and capturing device with the video images captured during the examination. In the video image of the safety injection nozzle, two or more circular grooves around the nozzle are shown as ellipse contours. In this paper, we propose a camera self-calibration method using a single image containing two circular grooves which are the greatest circles of the cylindrical nozzle whose radius and distance are known.

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