Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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Application of DMD for Phase Shifting in Moire Topology

DMD를 이용한 위상천이 모아레 3차원 형상 측정

  • Jeong, Kyung-Seok (School of Mechanical Engineering, Korea University of Technology & Education) ;
  • Jung, Yong-Sang (Department of Mechanical Engineering, Graduate School, Korea University of Technology & Education)
  • 정경석 (한국기술교육대학교 기계정보공학부) ;
  • 정용상 (한국기술교육대학교 대학원 기계공학부)
  • Received : 2011.04.05
  • Accepted : 2011.06.09
  • Published : 2011.06.30
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Abstract

The need for rapid and accurate measurement of 3-dimensional objects is increasing due to the paradigmatic shift in manufacturing from mass production to small batch production. A three dimensional measurement technique which can provide the dimensional information of the object manufactured or to be manufactured has been developed. This method is based on phase shifting moire topology. Digital-Micromirror-Device (DMD) has been used in generating phase shifting moire fringes. And the mechanically moving optical components used for phase shifting, which might result in measurement errors, have been replaced by the DMD. Inherent $2\pi$-ambiguity problem, occurring in the calculation of phase from the light intensity distribution due to the nature of arctangent function, has been overcome by adapting the phase unwrapping method. The advantage of this technique is the easy change of the range and the resolution of the measurement by simply changing the computer generated grid pattern with the appropriate combination of projection lens of various focal length.

생산방식의 변화에 따라 3차원 형상을 신속하고 정확하게 측정하는 것이 중요해졌다. 가장 훌륭한 비접촉 3차원 측정방법인 모아레 방법 중 잡음신호를 효과적으로 제거할 수 있는 위상천이 방법을 구현함에 있어 DMD를 이용하여 격자를 생성하고 이송하는 효과를 발생하도록 하였다. 컴퓨터에서 격자를 이송하고 위상천이를 발생하므로 기계적 이송으로 인한 잡음신호의 발생 가능성을 배제할 수 있으며 광학렌즈와의 적절한 조합을 통해 쉽게 분해능을 변화하며 3차원 정보 획득이 가능하다. 근본적인 $2\pi$ 모호성문제를 극복하기 위하여 2차원 위상정력을 실시하였다. 이 방법을 적용하여 3차원 형상의 측정을 수행하였다.

Keywords

References

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