• 제목/요약/키워드: gap and balance sensing

검색결과 2건 처리시간 0.017초

접촉형 변위센서를 이용한 LCD노광기용 스테이지 시스템 (Stage System for LCD Exposure Equipment Using Touch-type Displacement Sensor)

  • 임광국;서화일;조현찬;김광선;강흥석
    • 반도체디스플레이기술학회지
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    • 제6권1호
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    • pp.7-10
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    • 2007
  • In an effort to reduce weaknesses of existing laser displacement sensor-based system, a sensing device for distance and balance of mask-substrate gap using touch-type displacement sensor was suggested. The device suggested in this study is expected to solve the problems of prices and reflections, by means of a touch-type sensor. LCD exposure equipment stage system including suggested sensing device was realized to assess the characteristics of sensing the balance and gap between mask and substrate. It was verified that a touch-type displacement sensor-based device to adjust the balance and distance of mask-substrate gap suggested in this study can be applicable to LCD expose equipment in practice.

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전류와 자속의 궤환에 의한 자기베어링 시스템의 센서가 없는 변위 제어 (Displacement-Sensorless Control of Magnetic Bearing System using Current and Magnetic Flux Feedback)

  • 이준호;강민수;정용운;이정석;이기서
    • 대한전기학회논문지:시스템및제어부문D
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    • 제49권7호
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    • pp.339-345
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    • 2000
  • This paper deals with the displacement estimation of magnetically suspended simple 1 DOF(degree of freedom) system without the displacement sensor. Inherently electro-magnet for control has two natural feedback loops. One is the transfer function which represents the dependance of the amount of the magnetic flux on the gap displace-ments. The other is the transfer function expressing the properties that the back electromotive force is derived from the time derivative of the magnetic flux. Through these two feedback loops, information about the gap length can be represented by the magnetic flux and the coil current. This means that the gap length can be detected from these two states variables of the electromagnet without a displacements sensor(self-sensing). The displacement can be estimated with the magnetic flux subtracted by the coil current. In this paper we use a balance beam in order to deal with the displacement sensorless estimation of the magnetic bearing system. For the stable estimation of the gap displacements by using the method of self-sensing simple PD controller is used. We first show the mathematical model of the balance beam, and then we show the effectiveness of the current and flux feedback for making stable estimation of the gap displacements for the balance beam. Simulation results show the effectiveness of the current and flux feedback for good estimation of the displacement without using displacement sensor.

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