Fast and Fine Control of a Visual Alignment Systems Based on the Misalignment Estimation Filter

정렬오차 추정 필터에 기반한 비전 정렬 시스템의 고속 정밀제어

  • 정해민 ((주)STX조선해양 연구소) ;
  • 황재웅 (한국항공대학교 항공우주기계공학부) ;
  • 권상주 (한국항공대학교 항공우주기계공학부)
  • Received : 2010.03.22
  • Accepted : 2010.08.07
  • Published : 2010.12.01


In the flat panel display and semiconductor industries, the visual alignment system is considered as a core technology which determines the productivity of a manufacturing line. It consists of the vision system to extract the centroids of alignment marks and the stage control system to compensate the alignment error. In this paper, we develop a Kalman filter algorithm to estimate the alignment mark postures and propose a coarse-fine alignment control method which utilizes both original fine images and reduced coarse ones in the visual feedback. The error compensation trajectory for the distributed joint servos of the alignment stage is generated in terms of the inverse kinematic solution for the misalignment in task space. In constructing the estimation algorithm, the equation of motion for the alignment marks is given by using the forward kinematics of alignment stage. Secondly, the measurements for the alignment mark centroids are obtained from the reduced images by applying the geometric template matching. As a result, the proposed Kalman filter based coarse-fine alignment control method enables a considerable reduction of alignment time.


Supported by : 한국연구재단


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