• Journal of the Korea Institute of Military Science and Technology
• /
• v.2 no.1
• /
• pp.150-158
• /
• 1999

A driving system of a dynamic FOG compass with a stabilized platform is described. A stepping motor adopted as a driving motor is required to maintain a stable operation with constant speed and low oscillation for the proper operation of the FOG compass itself. The previous stabilization scheme operated on frequency-modulated supply is modified to include fuzzy control algorithm. The proposed scheme has advantages, particularly in the size, weight and flexibility of the driving system.

• Proceedings of the KIEE Conference
• /
• 1998.07e
• /
• pp.1840-1842
• /
• 1998

Gyroscope is a very important core sensor, as a rotation sensor in inertial space, in inertial guidance and navigation system on aeronautics, plane, vessel and so on for civilian and millitary applications. Mechnical gyroscopes, adopting a principle of spinning a top, have been used in many application system. These mechnical gyroscopes need high power consumption, long warming time and complicated peripheral devices. But fiber-optic gyroscopes, based on the Sagnac effect, have novel advantages as small volume. simple scheme, low power consumption and high reliability. So we have developed a Intermediate grade All-fiber Optic Gyroscope, which has open-loop and minimum reciprocal configuration scheme. We have designed feedback circuits for stability of amplitude and phase using four lock-in amplifier(LIA) circuits and also used for noise limitation. This paper describes the scheme of optical part and electronic part and also test results of this all-fiber optic gyroscope. The performance have been achieved as long-term bias drift of $9.54^{\circ}/h$, random walk of $0.0317^{\circ}/\sqrt{h}$ and dynamic range of ${\pm}150\;deg/s$.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.32B no.11
• /
• pp.1481-1488
• /
• 1995

Due to the low loss, broadband and accurate short time delay properties of optical fiber, it has attracted as a delay medium for high speed and broad-band signal processing. In this paper, we consider the coherent optical fiber filter of IIR lattice structure, which uses coherent light sources and consists of directional couplers whose coupling coefficients are restricted between 0 and 1. Considering restrictions of directional coupler, the design formulae and condition for realibility of optical fiber filter of IIR lattice structure which makes the optimal use of optical signal energy are derived.

• Journal of rehabilitation welfare engineering & assistive technology
• /
• v.8 no.2
• /
• pp.73-78
• /
• 2014

In this paper we propose a wearable elbow rehabilitation robot applied the mirror therapy for elbow rehabilitation. To implement the mirror therapy, a data suit for measuring healthy elbow motion is developed. A powered elbow exoskeleton wearing in paralyzed arm is controlled by the measured data from the healthy elbow motion. In experiments, the elbow rehabilitation exercise by the mirror therapy is performed. From the experimental results we show the wearable exercise robot including the data suit is applicable to the mirror therapy for elbow rehabilitation.

• Proceedings of the Optical Society of Korea Conference
• /
• 2000.08a
• /
• pp.220-221
• /
• 2000

가공용 레이저로는 $CO_2$, 루비, Nd:YAG, 아르곤 이온 레이저 등이 이용되고 있으며, 이중 펄스형 Nd:YAG 레이저는 $CO_2$ 레이저와 함께 레이저 가공에 널리 사용되는 고체 레이저로서 마킹(making), 트리밍(trimming), 리페어링(repairing) 등의 정밀 가공 분야에서 많은 실용화가 이루어져 왔다.$^{(1)}$ $CO_2$ 레이저의 경우 매질가스로 $CO_2$, $N_2$, He 등을 사용해야하므로 취급 및 유지보수가 불편하지만, 열전도율이 높고, 기계적 광학적으로 안정된 Nd:YAG 레이저는 램프에 의한 광 여기 방식이므로 유지보수가 쉽다. 또한 광 출력의 제어가 용이하며, 광파이버에 의한 빔 전송이 가능하여 산업기술 및 의료 분야에서의 적용이 더욱 더 확대되고 있다.$^{(2)}$ (중략)

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.631-634
• /
• 2005

This paper has been studied a optical fiber sensor offer important advantages such as electrically passive operation, EMI immunity, high sensitivity, and multi-plexing capabilities of this technology has been the characteristic. The shift in optical fiber Bragg wavelength with mass can be expressed. Using the shift in the optical fiber Bragg grating(FBG) center wavelength due to mass change.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.30B no.5
• /
• pp.34-42
• /
• 1993

Due to the low loss, broadband and accurate short time delay properties of optical fiber, it has attracted as a delay medium for high speed and broad-band signal processing. In this paper, we consider the coherent optical fiber filter of lattice structure, which uses coherent light sources and consists of directional couplers and optical fiber delay elements.The differences between the optical fiber filter and the ordinary digital filter are 1) the coupling coefficients of directional couplers are restricted between 0 and 1. 2) the optical signal is divided into ${j\sqrt{a}}and\;{j\sqrt{1-a}}$ at the directional coupler. Considering these restrictions, the design formulae and condition of realibility for optical fiber filter of lattice structure which makes the optimal use of optical signal energy are derived.

• Proceedings of the KIEE Conference
• /
• 2007.11a
• /
• pp.242-243
• /
• 2007

본 논문은 1310nm 단일모드 광섬유를 이용하여 온도센서로 활용하기 위한 연구이다. 기존광섬유센서의 연구는 복잡한 여러 가지 기기를 이용하여 구성된 시스템이었다. 그리고 산란 변화를 주기 위하여 Bragg 격자나 Pulse generator를 이용하여 광주파수의 변화를 측정하거나, YAG 레이저를 이용 벌크형 시스템을 택하여 구성하였는데 실험 환경을 구성하는 어려움과 측정된 데이터의 정확도에 대한 문제점이 있었다. 본 연구에서 제안한 유도 브릴루앙 산란(sBs: stimulated Brillouin scattering)광을 이용한 온도센서 시스템은 기존의 측정방식 보다 간소화된 직렬방식의 시스템이다. 광주파수에서 발생하는 노이즈와 애매한 결과에 대해서 신뢰성과 정확도를 확보하기 위하여 지능형인 뉴로-퍼지 알고리즘을 이용하여 분석함으로써 기존 시스템 보다 정확한 데이터를 얻고자 하였다. 본 연구에서 sBs는 빛의 산란 특성 중 광주파수가 온도에 변화에 대해 각각의 온도 변화당 천이가 이루어졌음을 측정하였다. 시스템에서 출력된 데이터를 뉴로-퍼지로 분석한 변화율은 1.1MHz/의 결과를 얻었다.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.3 no.2
• /
• pp.146-156
• /
• 1995

Growing international concern about environmental issues in recent years has led to new proposals for strengthening exhaust emission standards and fuel economy requirements throughout the world. The low emission vehicle(LEV) standards drawn up by the California Air Resources Board(CARB) in the U.S.A are noticeably stringent To cope with this regulation, a reduction of HC emission is the most important challenge for the automotive industry because HC emission levels are severer than any other components emission levels. In this paper, the apparatus for visulalizing the wall film flow in a intake manifold and the spark plug with optical fiber for detecting the signal from diffusion flame are developed to mal,e the HC formation mechanism clear. High speed camera system is also used to elucidate the correlation wall film flow and the diffusion flame. Using these methods, the effect of fuel injection systems such as injection direction, spray angle, atomised injection on HC emission levels is investigated. Consequently, the optimal fuel injection conditions for minimizing the wall film flow and reducing the HC emission are found through this research.

• Journal of the Semiconductor & Display Technology
• /
• v.6 no.3
• /
• pp.61-64
• /
• 2007

V-groove device was fabricated for precision coupling of planar optical splitter and optical fibers. V-groove was made through select wet etching of Si wafer by using KOH solution. Etching rate and surface roughness were checked, changing KOH composition(10, 20, 30, 33, 40 wt.%) and etching temperature (50, 60, 70, $80^{\circ}C$) to fabricate V-groove device effectively. Etching rate was the fastest as $1.84\;{\mu}m/min$ in case of etching by 20 wt.% KOH on $80^{\circ}C$, surface roughness was the best in case of etching by 33 wt. % KOH on $80^{\circ}C$.