• 제어로봇시스템학회논문지
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• 제7권8호
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• pp.697-702
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• 2001

The ring laser gyro(RLG) has been used extensively in strapdown inertial navigation system(SDINS) because of the apparent of having wide dynamic range, digital output and high accuracy. The dithered RLG system has dynamic motion at sensor level, caused by the dithering motion to overcome the lock-in threshold. In this case, an attitude error is produced by not only the true coning of the vehicle motion but also the pseudo coning of the sensor motion. This paper describes the definition of the multi-frequency coning motion and its noncommutativity error to reject the pseudo coning error produced by the sensor motion such as the dithered RLG. The simulation results are presented to minimize the multi-frequency coning error.

• 제어로봇시스템학회논문지
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• 제12권6호
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• pp.608-613
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• 2006

Any input acceleration that bends RLG dithering axis causes flexure error, which is a source of the noncommutative error that can not be compensated by simply using integrated gyro sensor output. This paper introduces noncommutative error equations that define attitude errors caused by flexure errors. In this paper, flexure error is classified as sensor level error if the sensing axis coincides with the dithering axis and as system level error if the two axes do not coincide. The relationship between gyro output and the rotation vector is introduced and is used to define the coordinate transformation matrix and angular motion. Equations are derived for both sensor level and system level flexure error analysis. These equations show that RLG based INS attitude error caused by flexure is directly proportional to time, amount of input acceleration and the dynamic frequency of the vehicle.

• 한국군사과학기술학회지
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• 제17권4호
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• pp.537-543
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• 2014

RLG(Ring Laser Gyroscope) is a main device of LINS(Laser Inertial Navigation System). RLG has the lock-in region in which there is no output signal. To alleviate the lock-in problem, a mechanical oscillation, the dither motion, is applied on RLG. A LPF(Low Pass Filter) is usually used on the output of RLG and accelerometer to remove the noise that is made by the dither motion. When the LINS is induced the disturbance during the initial alignment, it takes more time on alignment due to the use of the LPF and a fixed gain controller. In this paper, an initial alignment using UKF(Unscented Kalman Filter) is designed and analysed. Analysis include comparison between conventional initial alignment loop using fixed gain type controller and proposed initial alignment using UKF. Moreover, Disturbance inducing test results are demonstrated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1488-1490
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• 2008

The gyroscope is the sensor for detecting the rotation in inertial reference frame and constitute the navigation system together an accelerometer. As the inertial reference equipment for attitude determination and control in the satellite, the mechanical gyroscope has been used but it bring the disturbance for mass unbalance so the disturbance give a bad influence to the observation satellite mission because the mechanical gyroscope has the rotation parts. During the launch, The mechanical gyroscope is weak in vibration, shock and has the defect of narrow operating temperature range so it need the special design in integration. Recently the low orbit observation satellite for seeking the high pointing accuracy of image camera payload accept the FOG(Fiber Optic Gyro) or RLG(Ring Laser Gyro) for the attitude determination and control. The Ring Laser Gyro makes use of the Sanac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. It need the 1000V DC to create the He-Ne plasma in discharge tube. In this paper, the design process of the High Voltage Power Supply for RLG(Ring Laser Gyroscope) is described. The specification for High Voltage Power Supply(HVPS) is proposed. Also, The analysis of flyback converter topology is explained. The Design for the HVPS is composed of the inverter circuit, feedback control circuit, high frequency switching transformer design and voltage doubler circuit.

• 한국도서관정보학회지
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• 제35권3호
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• pp.175-204
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• 2004

디지털 정보자원은 장기적 보존 및 다음 세대로의 접근을 보장하기 위한 상세한 베타데이터를 필요로 한다. 본 연구는 먼저 디지털 정보자원의 특성과 디지털 보존의 개념, 디지털 정보자원의 장기 보존과 접근을 위한 메타데이터의 필요성을 조명하였다. 디지털 정보자원을 위한 상호운용적인 보존 베타데이터 개발에 근거가 되고 있는 OAIS 참조 모형을 살펴보았다. 이어 실제 OAIS 참조 모형을 적용한 CEDARS, NLA, NEDLIB, OCLC/RLG 디지털 정보자원의 보존 메타데이터를 대상으로 하여 그 개발 과정, 목적 및 메타데이터 요소 세트를 각각 구체적으로 비교 분석하였다. 본 분석 결과를 기초로 하여, 향후 우리나라의 디지털정보자원의 장기 보존과 접근을 위한 상호운용성을 갖춘 보존 메타데이터의 기본적인 요소 세트 설정 방안을 제시하였다.

• 항공우주기술
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• 제6권1호
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• pp.109-113
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• 2007

위성에는 자세제어를 위하여 광학식 자이로가 사용되고 있다. 여러 종류의 자이로중 타자이로에 비해 RLG는 정밀도는 높으나 레이저 방전현상을 이용하므로 방전관 전극의 수명이 곧 자이로의 수명을 결정짓는 요소이다. 그래서 현재는 비교적 짧은 4년의 수명을 목표로 하는 저궤도 위성의 자세제어를 위하여 장착되어 사용되고 있다. 링 레이저 자이로 (RLG)의 전자모듈 전원은 크게 레이저를 발진시키기 위한 전압과(Discharge 전압), Lock-in을 보상하는 Dither를 구동하는 전압(Dither 구동 전압)과 광경로를 일정하게 유지하기 위해 미러를 구동하는 전압(PLC 구동 전압)인 고전압계통의 전원과 로직회로와 아날로그 회로를 구동하는 저전압 계통의 전원으로 나눌 수 있다. 본 논문에서는 Flyback Converter를 이용하여 헬륨-네온 레이저의 플라즈마를 생성하고 발진을 유지하는 Discharge전압을 포함하는 자이로 전력계 설계과정을 제시한다.

• 제어로봇시스템학회논문지
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• 제17권11호
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• pp.1106-1116
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• 2011

LINS (Laser Inertial Navigation System) consists of RLG (Ring Laser Gyroscopes)/accelerometers and provides real-time navigation information to the target system. Therefore it is very important to make a decision in the real time whether LINS is in the normal operation or not. That is called a fault detection method. In this paper, we propose the fault detection method of LINS based on the overlapping model. We also show that the fault detection probability is increased through overlapping the hardware model and the software model. It is verified through the long-term operation and RAM (Reliability Availability Maintainability) analysis of LINS that the fault detection method proposed in this paper is able to detect about 97% of probable system failures.

• 정보관리연구
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• 제32권3_4호
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• pp.31-42
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• 2001

전문도서관이 당면한 문제는 변화하는 출판 및 도서관 환경 속에서 제한된 자원으로 이용자의 다양한 요구를 만족시키기가 더욱 어려워지고 있다는 점이다. 최근 인터넷과 정보기술의 발달 그리고 전자자원의 증가는 자료의 확인과 전달 시스템의 향상 등 공동수서의 기술적인 기반을 제공해 주었다. 본 논문은 전문도서관 공동수서의 배경과 방법을 CRL, OhioLINK, RLG Conspectus, TRLN 등의 사례들을 중심으로 살펴보고, 효과적인 공동수서를 위한 과제와 전략을 제시하였다.

• International Journal of Control, Automation, and Systems
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• 제2권4호
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• pp.536-541
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• 2004

It is important to estimate and calibrate sensor errors in maintaining the performance level of SDINS. In this study, an estimation technique of fixed sensor errors for SDINS calibration is discussed. First, the fixed errors of gyros and accelerometers, excluding gyro biases are estimated by the navigation information of SDINS in multi-position. The SDINS with RLG includes flexure errors. In this study, the gyros flexures are out of consideration, but the proposed procedure selects certain positions and rotations in order to minimize the influence of flexures. Secondly, the influences of random walks, flexures and orientation errors are verified via numerical simulations. Thirdly, applying the previous estimated errors to SDINS, the estimation of gyro biases is conducted via the additional control signals of close-loop self-alignment. Lastly, the experiments illustrate that the extracted calibration parameters are available for the improvement of SDINS.

• 도서관문화
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• 제30권6호통권259호
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• pp.51-53
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• 1989

이 자료는 1982년에 발표된 미국의 연구도서관협의회 보존 편람(RLG Preservation Manual)가운데 1983년도 미국도서관협회 연차총회, 도서관행정 및 경영 부회, 도서관건물 및 건물 분회 (1983 ALA Annual Conference, LAMA Buildings and Equipment Section, Buildings for College & University Libraries Committee)에서 발췌 소개된 내용을 우리말로 전역한 것이다.