• Title/Summary/Keyword: RLG

Search Result 42, Processing Time 0.027 seconds

Flexure Analysis of Inertial Navigation Systems

  • Kim, Kwang-Jin;Park, Chan-Gook;Park, Jai-Yong
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2004.08a
    • /
    • pp.1958-1961
    • /
    • 2004
  • Ring Laser Gyroscopes used as navigational sensors inherently experience a lock-in region, where very low rotational rates are not measurable. Most RLG manufacturers use a mechanical dither motor that applies a small oscillatory rotational motion larger than this region to resolve this problem. Any input acceleration that bends this dithering axis causes flexure error, which is a 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.

  • PDF

The Gyro High Voltage Power Supply Design for Attitude Control in the Satellite (저궤도 위성 자세제어용 자이로 고전압 발생기 설계)

  • Kim, Eui-Chan;Lee, Heung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.57 no.3
    • /
    • pp.403-408
    • /
    • 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.

Recent Development Trends of Fiber Optic Gyroscope in Space Application (우주용 광섬유자이로 개발동향)

  • Jung, Dong-Won;Kim, Jeong-Yong;Oh, Jun-Seok;Roh, Woong-Rae
    • Current Industrial and Technological Trends in Aerospace
    • /
    • v.8 no.2
    • /
    • pp.76-85
    • /
    • 2010
  • This paper discusses recent development trends of fiber optic gyroscope (FOG) in space application. Fiber optic gyroscope utilizes Sagnac effect to measure the angular rate of a rotating object in space. Having a rather short development history compared to ring laser gyroscope (RLG), the fiber optic gyroscope, owing to the emerging technologies in fiber optic society and the digital signal processing technique, reveals itself as a noteworthy replacement of the ring laser gyroscope in the space mission. This paper summarizes the current trends of fiber optic gyroscope based on the actual products commercialized in the market over the last decades, while presenting the future development trends of the fiber optic gyroscope in the space exploration.

  • PDF

Stripping Method of Ring Laser Gyroscope Based on Measurement Model of Dither Motion (디더 운동 측정치 모델 기반 링레이저 자이로 스트리핑 방법)

  • Kim, Cheon-Joong;Shim, Kyu-Min
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.17 no.4
    • /
    • pp.531-536
    • /
    • 2014
  • There are trapping and stripping methods as the technique to remove the dither motion from RLG(Ring Laser Gyro) output. V/F converter output of angular sensor to measure the dither motion is used in stripping method. But bias and scale factor error is always included in V/F converter output and is a critical limiting factor for the wide application of stripping method to RLG. Therefore there have been many researches to solve this problem. The method to accurately estimate the bias and scale factor error of V/F converter using measurements of the angular sensor acquired at data sampling rate of INS is presented in this paper. To this end, stripping technique based on model of dither motion is newly applied.

A Study on Long-term Preservation of the Cultural Archetypes in Digital Audio Format (문화원형콘텐츠의 장기보존에 관한 연구 - 디지털 소리자료를 중심으로 -)

  • Suh, Hye-Ran
    • Journal of the Korean BIBLIA Society for library and Information Science
    • /
    • v.17 no.2
    • /
    • pp.65-82
    • /
    • 2006
  • The purpose of this study is to present some basic information essential for planning long-term preservation of digital audio files, which have been collected through 'Cultural Archetypes Digitization Project' by the Korea Culture & Content Agency. Needs and limitations of digitization of audio resources for their long-term preservation, digital audio archiving models(OAIS Reference Model and AHDS Model), some technical principles for audio digitization and preservation, preservation metadata and storing media for digital audio files were discussed. Compliance to the requisites listed in Audit Checklist for the Certification of Trusted Digital Repositories of RLG & NARA was suggested. It was also recommended to review the appropriateness of collaborating on digital preservation project with other institutions.

Morphology and Histology of the Digestive Tract of the Black Sea Bream, Acanthopagrus schlegeli (감성돔 (Acanthopagrus schlegeli) 소화관의 구조 및 조직학적 특징)

  • LEE Jung Sick;CHIN Pyung
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.32 no.5
    • /
    • pp.642-648
    • /
    • 1999
  • The digestive tract of the black sea bream, Acanthopagrus schlegeli is composed of esophagus, stomach, intestine, anus and four or five pyloric caeca. Pyloric caecum is a blind sac in shape and originated from pyloric portion of the stomach. Relative length of But (RLG), that is length of digestive tract to standard length, is 1.04 (n=10). Histological layer of the digestive tract is composed of serous membrane, muscular layer, undeveloped submucosal layer and mucosal layer. The mucosal folds of the esophagus are regular branched form, Esophageal muscularis mucosae is well-developed. Mucosal epithelial layer is composed of cuboidal or columnar epithelium and mucous secretory cell. Microvilli are absent in the free surface of mucosal epithelium. The mucosal folds of the stomach are regular unbranched form. The stomach has a well-developed muscular layer and muscularis mucosae. Microvilli are present in the free surface of mucosal surface epithelium. The fundic portion of the stomach have a well-developed gastric gland and more numerous secretory granules than the other parts. The mucosal folds of the pyloric caeca and the intestine are irregular branched form, Intestine is divided into the anterior, mid and posterior intestines with length of mucosal folds and histological features, Posterior intestine has a more developed striated border and goblet cells than the other parts. Mid intestine has a more abundant absorptive cells than the other parts in the intestine and pyloric caeca.

  • PDF

Interferometric Measurement of Flexure Error in a Ring Laser Gyroscope (간섭계를 이용한 링레이저 자이로스코프의 플렉셔 오차 측정)

  • 김정주;이동찬;이재철;조민식;권용율
    • Proceedings of the Optical Society of Korea Conference
    • /
    • 2003.07a
    • /
    • pp.272-273
    • /
    • 2003
  • 링레이저 자이로스코프(Ring Laser Gyroscope-이하 RLG)는 비행기, 유도무기, 선박, 지상무기 등의 관성항법장치(Inertial Navigation System)에 사용되는 각속도 센서로서 항체의 위치와 자세 정보를 제공하는 핵심 구성품 중의 하나이다. 각속도 검출 원리는 삼각형 또는 사각형의 공진기에 He과 Ne을 혼합한 이득매질을 사용하여 서로 반대방향으로 회전하는 두 개의 레이저 빔을 발생시켜서 Sagnac 효과에 의해 외부의 회전 입력을 받을 때 서로 다른 광 경로의 차이로 인한 두 빔의 간섭으로 회전각을 검출한다. (중략)

  • PDF

A Comparison of the Effect of Lidocaine or Sodium Bicarbonate Mixed with Rocuronium on Withdrawal Movement, Mean Arterial Pressure and Heart Rate during Rocuronium Injection (Rocuronium과 Lidocaine 또는 Sodium Bicarbonate의 혼합투여가 Rocuronium 정맥주사 동안의 회피 반응, 평균 동맥압 및 심박수에 미치는 효과 비교)

  • Lee, Sung-Suk;Yoon, Hae-Sang
    • Journal of Korean Academy of Nursing
    • /
    • v.39 no.2
    • /
    • pp.270-278
    • /
    • 2009
  • Purpose: This study was performed to find out the effects of lidocaine or 8.4% sodium bicarbonate mixed with rocuronium on mean arterial pressure, heart rate and withdrawal movement. Methods: Data collection was performed from December 15, 2006 through May 31, 2007. Seventy-five patients with American Society Anesthesiologist (ASA) physical status I & II, under general anesthesia, were randomly assigned to 1 of 3 groups: R group (RG) received rocuronium 0.6 mg/kg; RL group (RLG), rocuronium 0.6 mg/kg mixed with 2 mL of 2% lidocaine; RS group (RSG), rocuronium 0.6 mg/kg with the same volume of 8.4% sodium bicarbonate. Mean arterial pressure, heart rate and withdrawal movement were observed from its injection until 5 min after endotracheal intubation. Results: The incidence of withdrawal movement with its corresponding injections was 72%, 40% and 4% in RG, RLG and RSG, respectively (p<.001). Score of withdrawal movement was the lowest in RSG of all groups (p<.001). While mean arterial pressure (p=.011) in RSG decreased significantly, and heart rate (p=.003) in RG increased more with its injection than before induction of anesthesia. Conclusion: Administration of the equivalent volume of 8.4% sodium bicarbonate with rocuronium is more effective than that of lidocaine with rocuronium compared with rocuronium only, in preventing withdrawal movement and in stabilizing mean arterial pressure and heart rate.

Morphology and Histochemical Characteristics of the Alimentary Tract in Surfperch, Ditrema temmincki (망상어, Ditrema temmincki 소화관(消化管)의 형태(形態).조직화학적(組織化學的) 특징(特徵))

  • Lee, Jung-Sick;Chin, Pyung
    • Korean Journal of Ichthyology
    • /
    • v.7 no.2
    • /
    • pp.140-149
    • /
    • 1995
  • Morphology and histochemical characteristics of the alimentary tract in surfperch, Ditrema temmincki were investigated by histological observation. The relative length of gut(RLG) in surfperch, that is the postpharyngeal portion of the alimentary tract, is about 0.89 to standard length. The absence of a stomach, which is the part of expantion of the alimentary tract between esophageal end and the entrance of the bile duct into the intestine, was observed. The alimentary tract is divided into the esophagus, esophageal-intestine part, anterior intestine, mid intestine, posterior intestine, intestinorectum part, rectum, rectal-anus part, and anus by morphology and histochemical features. Morphology of mucosal folds is the most complexity in the rectum and the tunica muscularis of the esophagus and anus is more advanced than those of other parts. The epithelial layers of mucosal folds consist of columnar epithelium except for cuboidal cells of the anterior part of the esophagus. The goblet cells and polysaccharide absorptive cells were observed in the alimentary tract. Nutritive polysaccharide is mainly absorbed by the absorptive cells in the posterior intestine of the surfperch.

  • PDF

A Research on the Development Initiative for Public Practices of Local Governmentsin Korea - Focused on the Local Adaptation Planning in Ecosystem Sector - (지자체 기후변화 적응실무 발전방향 연구 - 생태계 분야 기후변화 적응 시행계획 수립 및 이행을 중심으로 -)

  • Yeo, Inae;Hong, Seungbum
    • Journal of Environmental Impact Assessment
    • /
    • v.29 no.2
    • /
    • pp.79-92
    • /
    • 2020
  • This study aimed at analyzing the current status and further needs of ecological information which is provided with the civil servants in the process of climate change adaptation planning in ecosystem sector and at providing suggestions for future development of ecological knowledge on climate change. Therefore, we conducted a questionary survey titled as "the knowledge-base and information needs for climate change adaptation in ecosystem sector" with the civil servants who are engaged with adaptation practices in the ecology related divisions in 17 regional local governments (RLG) and the affiliated basic local governments (BLG) in Korea. As a result, the characteristics of ecological information which is applied in public practices was analyzed and strategies for improved utilization was suggested. 75% of the respondents (RLG 85% and BLG 72%) were aware of the relativeness between the existence and utilization of ecological information and the execution of climate adaptation practices in ecosystem sector. They were agreed with the necessity of ecological information not only in adaptation practices but also overall affairs in the ecological related division in the local government (RLG 82% and BLG 72%). The current situation of utilizing ecological information which is produced from central orlocal government to civil affairs were only represented as 64 persons (28%) in RLG and 42 persons (18%) in BLG. One of the major obstacles that the respondents confront with when applying ecological information to public practices was deficit of prior knowledge on the ecological information itself, such as awareness of the characteristics of ecological information and the link with public affairs for adaptation plans. Therefore, delivering current knowledge and ecological information on climate change by educational and promotional method is an urgent priority to the civil servant. The future needs on ecological information for local government servants were deduced as basic information on local ecosystem and applied knowledge on local development to meet the biodiversity conservation and ecosystem services at the same time. The respondents expected not only the specific guidelines for using ecological information to apply on the adaptation plans in the relevant divisions of the local governments but also the institution where the usage activation of ecological information would be operated and managed to enhance the information utilizing structure in the local government. In the nation-wide, the capacity of local governments should be enhanced with adaptation knowledge and the application of appropriate information to the public practices by central government's aiding with the better quality of information, its public promotion, and the applicability to civil affairs.