Study on Extraction of the Center Point of Steam Generator Tubes

증기발생기 세관의 중심좌표추출에 대한 연구

  • 조재완 (한국 원자력연구소 내방사선 로봇개발 과제) ;
  • 김창회 (한국 원자력연구소 내방사선 로봇개발 과제) ;
  • 서용칠 (한국 원자력연구소 내방사선 로봇개발 과제) ;
  • 최영수 (한국 원자력연구소 내방사선 로봇개발 과제) ;
  • 김승호 (한국 원자력연구소 내방사선 로봇개발 과제)
  • Published : 2002.06.01

Abstract

This paper describes extraction procedure for the center coordinates of steam generator tubes of Youngkwang NPP #6, which are arrayed in triangular patterns. Steam generator tube images taken with wide field-of-view lens and low-light lamp mounted on a ccd camera tend to have low contrast, because steam generator is sealed and poorly illuminated. The extraction procedures consists of two steps. The first step is to process the region with superior contrast in entire image of steam generator tubes and to extract the center points. Using the extracted coordinates in the first step and the geometrical array characteristics of tubes lined up in regular triangle forms, the central points of the rest region with low contrast are estimated. The straight lines from center point of a tube to neighbour points in horizontal and 60, 120$^{\circ}$ degree directions are derived. The intersections of straight line In horizontal direction and slant line in regular triangle direction are selected as the center coordinates of steam generator tubes. The Chi-square interpolation method is used to determine the line's coefficients in horizontal and regular triangle direction.

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