• Title/Summary/Keyword: Optical-type Guide sensor

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Feasibility study on the development of Liquid crystal-optical fiber temperature sensor for minimal invasive laserthermia (LC(Liquid crystal)-광섬유를 이용한 최소 침습적 레이저 온열 치료용 온도 측정 센서의 개발을 위한 기초 연구)

  • Lee, Bong-Soo;Hwang, Young-Muk;Chung, Soon-Cheol
    • Journal of Sensor Science and Technology
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    • v.12 no.5
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    • pp.225-230
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    • 2003
  • Nowadays, laserthermia is widely used to treat malignant tumors with generating heat as the one of minimal invasive surgeries. Generally, the laserthermia probe system consists of the fiber-optic laser and light guides, image guide and temperature sensor. It is very important to measure the temperature of treating tumor and make a stable temperature ($42{\sim}43^{\circ}C$) during the treating time. Therefore, laserthermia probe needs temperature sensor which can measure it exactly and fast. In this study, to develop a new type of temperature sensor with LC(liquid crystal) and optical fiber, the reflectivity of LC according to the temperature changes are measured. Also, the relationships are derived from the results.

Design and Control of an Active Magnetic Bearing for Linear Motors (리니어 모터를 위한 능동 자기 베어링의 설계 및 제어)

  • 양광원;허경무
    • Proceedings of the IEEK Conference
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    • 2001.06e
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    • pp.119-122
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    • 2001
  • This paper deals with new type of active magnetic bearing (AMB) for the linear motors. We adopted optical sensing mechanism for the gap sensing. Using the laser and the PSD (Position Sensitive Device), the absolute rotor position is obtained independent of the profile of the guide rail. With this measurement, the rotor can be controller to follow the straight beam of the laser. Another advantage of optical sensing mechanism might be the elimination of the possible interference between the proximity sensor and the electro-magnet. By adopting the push-full actuating mechanism, the bearing stiffness is increased near the equilibrium position. For the simplicity, distributed control system is constructed. Eight independent PID control algorithm is used with the full order observer. Several simulation md test results are presented.

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