• 제목/요약/키워드: optical sensors

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삽입된 광강도형 광섬유센서가 지능형 복합재 구조물의 건전성에 미치는 영향 및 피로손상 감시 (Effect on the structural integrity and fatigue damage monitoring of smart composite structures with embedded intensity based optical fiber sensors)

  • 이동춘;이정주;서대철;허증수
    • 센서학회지
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    • 제10권1호
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    • pp.42-51
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    • 2001
  • 본 연구에서는 복합재료에 삽입된 광섬유센서의 인장하중하에서의 정적 물성치와 피로하중하에서의 동적 물성치를 실험적인 방법과 유한요소해석을 통하여 고찰하였다. 결과에 의하면 삽입된 광섬유센서는 인접한 강화섬유에 수직한 방향으로 삽입된 피로하중의 경우를 제외하고 복합재료의 기계적인 물성치에 큰 영향을 끼치지 않는다고 결론지을 수 있다. 광강도형 광섬유센서를 복합재료 적층판에 삽입하여 복합재 적층판의 강성저하를 측정함으로써 직교적층판 피로손상을 검출하였다. 이 실험의 결과에 의하면 광강도형 광섬유센서는 간단하고 저렴한 장치와 측정된 신호의 복잡한 후처리 과정이 필요 없다는 장점으로 인하여 구조물의 강성저하를 측정하여 피로손상을 감시하는데 있어서 큰 잠재력을 가진다고 할 수 있다. 또한 삽입된 광강도형 광섬유센서는 우수한 내 피로성과 넓은 강성측정 범위를 보였다.

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A Study on Fiber Optic Hydrophone with Double Interferometers for Optical Path Length Compensation

  • Kim, Jeong-suk;Yoon, Hyun-gyu;Seol, Jae-soo
    • The Journal of the Acoustical Society of Korea
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    • 제21권1E호
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    • pp.25-30
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    • 2002
  • We report on the development of a fiber optic hydrophone consists of a sensing Michelson interferometer and a compensating Mach-Zehnder interferometer for optical path length compensation. The double interferometer configuration has the following advantages: the hydrophone can be made more small; a laser source with a relatively short coherence length can be used; and the compensating interferometer can be located near the signal processing electronics, far away from the sensing interferometer and noise introduced by reference arm can be greatly reduced. The performance of the hydrophone is evaluated experimentally by immersing the sensing interferometer in a water tank to detect underwater acoustic signals generated by an acoustic wave projector. Experimental results show that over the frequency range of 1 to 4 kHz, the hydrophone has an almost flat response with an average normalized sensitivity of -302 dB re 1/ μ Pa.

NON-CONTACT SENSORS FOR DETECTING DISTANCE FROM THE FIELD SURFACE

  • Lee, Jeyong-;Minoru-Yamazaki;Akira-oida;Hiroshi-Nakashima;Hiroshi-Shimizu
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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    • pp.373-382
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    • 1993
  • A non-contact sensor for detecting distance from field surface to a predetermined location of a tractor will be useful to control precise height of implements such as tillage machinery, mowers etc.. An optical and an ultrasonic sensors were designed and fabricated . The indoor and outdoor experiments were conducted to obtain the static and dynamic characteristics of the two sensors at several moisture levels of four soils and on the soil surface with a designed shape. The results revealed that the optical sensor is unsuitable for soils with high moisture content but showed better detecting accuracy on the irregularity of soil surface.

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SOI 슬롯 광 도파로 기반 단일 및 삽입-분기 채널 링-공진형 바이오·케미컬 집적광학 센서의 제원에 대한 감도 해석 (Sensitivity Analysis for Specifications of Silicon-on-Insulator (SOI) Slot Optical Waveguide-based Single and Add-drop Channel Ring-resonant Biochemical Integrated Optical Sensors)

  • 장재식;정홍식
    • 센서학회지
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    • 제31권2호
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    • pp.107-114
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    • 2022
  • The effects of ring radius and coupling spacing on the free spectral range (FSR), full width at half maximum (FWHM), quality factor, and sensitivity of single-channel and add-drop channel slot ring resonators were systematically investigated using FIMMPROP and PICWAVE numerical software. The single-channel ring resonator exhibited better characteristics, namely, a wider FSR and narrower FWHM compared with the add-drop structure; thus, it was evaluated to be more suitable for biochemical sensors. The FSR, FWHM, quality factor, and sensitivity for a single channel ring resonator with a radius of 59.4 ㎛ and coupling gap of 0.5 ㎛ were 2.4 nm, 0.087 nm, 17677, and 550 [nm/RIU], respectively.

간섭잡음을 억압한 양극성 수신기와 PN 부호에 의한 광 CDMA 방식을 사용한 센서 네트워크 (Multiple Access Interference Suppressed Sensor Network Using Optical CDMA with Bipolar Receiver and Modified PN Code)

  • 박상조;김봉규
    • 정보처리학회논문지C
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    • 제13C권3호
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    • pp.311-316
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    • 2006
  • 양극성수신기와 무선통신에서 널리 사용되고 있는 PN(pseudo random noise) 부호를 수정하여 적용시킨 광 CDMA 방식을 사용한 광센서 네트워크를 제안한다. 광 센서 네트워크에서 특성을 수치적으로 분석하였다. 센서사이와 광 CDMA의 디코더에 광섬유형지연기를 사용하여 광 CDMA의 인코더와 디코더간 동기를 맞추고, 광지연기의 지연을 PN 부호의 칩폭보다 크게 하면 센서간 간섭잡음을 완전히 제거할 수 있다. 광 신호간 비트 잡음이 잡음전력을 지배하기 때문에 광센서 네트워크에 접속할 수 있는 광 센서의 수를 증가시키기 위하여 광신호간 비트 잡음을 억압하여야 한다.

광섬유센서를 이용한 Beam-column 조인트의 하중에 따른 변위 계측 (Monitoring of Beam-column Joint Using Optical Fiber Sensors)

  • 김기수
    • 한국소음진동공학회논문집
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    • 제15권1호
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    • pp.3-11
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    • 2005
  • For monitoring of the civil and building structure, optical fiber sensors are very convenient. The fiber sensors are very small and do not disturb the structural properties. They also have several merits such as electro-magnetic immunity, long signal transmission, good accuracy and multiplexibility in one sensor line. Strain measurement technologies with fiber optic sensors have been investigated as a part of smart structure. In this paper, we investigated the possibilities of fiber optic sensor application to the monitoring of beam-column joints of structures. We expect that the fiber optic sensors replace electrical strain gauges. The commercial electric strain gauges show good stability and dominate the strain measurement market. However, they lack durability and long term stability for continuous monitoring of the structures. In order to apply the strain gauges, we only have to attach them to the surfaces of the structures. In this paper, we investigate the possibility of using fiber optic Bragg grating sensors to joint structure. The sensors show nice response to the structural behavior of the joint.