• Title/Summary/Keyword: gyroscopes

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Principles and Prospects of Sagnac Interferometer Gyroscopes (사냑간섭계 원리를 이용한 자이로의 원리와 발전 전망)

  • Shim, Kyu-Min
    • Korean Journal of Optics and Photonics
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    • v.23 no.5
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    • pp.203-210
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    • 2012
  • Sagnac interferometer gyroscopes can be divided into three large generations using starting points of time or highlights of their research. As the first generational Sagnac interferometer, the ring laser gyroscopes have been studied since the 1960s by laser invention, and as the second generational Sagnac interferometer, the fiber optic gyroscopes have been studied since the 1970s by invention of optical fiber for communication. In the latter half of the 1990s, after having confirmed the wave theory of the atom, studies of atomic interferometers were started for a next generation gyroscope application. This paper discusses the operation principles, application, and future prospects of these three generations of Sagnac gyroscopes.

The Fiber Optic Gyroscope (II) (광섬유 자이로스코프(II))

  • 이석정;배정철;홍창희
    • Journal of the Korean Institute of Navigation
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    • v.19 no.1
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    • pp.71-83
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    • 1995
  • Various types of optical gyroscopes have been proposed and researched to the present in the world. This paper provides an overview of the types of optical gyroscopes, and also introduces technical principles, characteristics, advantages and disadvantages for each type. Moreover, the critical problems in a design have been discussed.

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On the control of vibratory MEMS gyroscopes

  • Choura, S.;Aouni, N.;El-Borgi, S.
    • Smart Structures and Systems
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    • v.6 no.7
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    • pp.793-810
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    • 2010
  • This paper addresses the control issue of vibratory MEMS-based gyroscopes. This study considers a gyroscope that can be modeled by an inner mass attached to an outer mass by four springs and four dampers. The outer mass itself is attached to the rotating frame by an equal number of springs and dampers. In order to measure the angular rate of the rotating frame, a driving force is applied to the inner mass and the Coriolis force is sensed along the y-direction associated with the outer mass. Due to micro-fabrication imperfections, including anisoelasticity and damping effects, both gyroscopes do not allow accurate measurements, and therefore, it becomes necessary to devise feedback controllers to reduce the effects of such imperfections. Given an ideal gyroscope that meets certain performance specifications, a feedback control strategy is synthesized to reduce the error dynamics between the actual and ideal gyroscopes. For a dual-mass gyroscope, it is demonstrated that the error dynamics are remarkably decreased with the application of four actuators applied to both masses in the x and y directions. It is also shown that it is possible to reduce the error dynamics with only two actuators applied to the outer mass only. Simulation results are presented to prove the efficiency of the proposed control design.

Gyroless Attitude Estimation of the Sun-Pointing Mode Satellite

  • Ahn, Hyo-Sung;Lee, Seon-Ho
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.876-881
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    • 2003
  • Reliable attitude estimation during the launch and early orbit phase is a critical issue for a satellite. Typically gyroscopes and other sensors are utilized to estimate the attitude during this phase. It is difficult to estimate the attitude quickly and reliably using gyroscopes because it requires a large computational load and accurate sensor measurements. Furthermore, the gyroscope failure may lead to the loss of the satellite. This paper suggests a simple attitude estimation method of a low earth orbit satellite without using gyroscopes, but only using sun sensors and magnetometers in the sun-acquisition mode. Using Kompsat-I telemetry data, we verified that the suggested algorithm provides attitude estimation within 3 degrees on each axis.

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Dynamic Characteristics of Vertically Coupled Structures: Application to Micro Gyroscopes (수직방향으로 연성된 구조물의 진동 특성: 마이크로 자이로센서에 응용)

  • Kim, Taek-Hyun;Lee, Seung-Yop
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1918-1924
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    • 2000
  • Dynamic characteristics of a vertically coupled structure used for micro gyroscopes, is studied. The coupled motion between the reference and sensing vibrations causes the zero-point output which means non-zero sensing vibration without angular velocity. This structural coupling deteriorates sensing performance and dynamic stability. We theoretically analyze dynamic characteristics associated the coupling phenomenon. Effects of reference frequency and coupling factor on the rotational direction and amplitude of elliptic oscillation are studied. A method to predict the existence of curve veering or crossing in frequency trajectories is introduced for the application to the design of micro gyroscopes with a vertically decoupled structure.

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Precision Calibration of Gyroscopes for Improving Dead-Reckoning Accuracy in Mobile Robots (이동로봇의 추측항법 정확성을 개선하기 위한 자이로스코프의 정확도 교정)

  • Ko Jae-Pyung;Yun Jae-Mu;Lee Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.11 no.5
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    • pp.463-470
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    • 2005
  • This paper describes a method aimed at improving dead-reckoning accuracy with gyroscopes in mobile robots. The method is a precision calibration procedure for gyroscopes, which effectively reduces the ill effects of nonlinearity of the scale-factor and temperature dependency. This paper also describes the methods of gyro data collection fur all ambient temperature$(-40^{\circ}C{\~}+80^{\circ}C)$ using cubic spline interpolation and defining the error function. The sensor used was a vibrating gyroscope called the EWTS82NA21, which is low lost and commonly used in car navigation system, made by Panasonic. This angular rate sensor utilizes Coriolis force generated by a vibrating tuning fork. The paper also provides experimental results to check the performance and the effectiveness of the proposed method.

Design of a 3DOF motion capture system for HMD using micro gyroscopes

  • Song, Jin-Woo;Chung, Hak-Young;Park, Chan-Gook;Lee, Jang-Gyu;Kang, Tae-Sam;Park, Kyu-Cheol
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.64.2-64
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    • 2001
  • In this paper, fabricated is a motion capture and attitude detection system for Head Mounted Display HMD composed of three low-price and low-grade micro gyroscopes and a micro-controller, To calculate attitude of a body, modified INS algorithm is used. Because the micro gyroscope has much bias drift error, scale factor error, and run-to-run bias error, the motion of a body can not be measured exactly if the general INS algorithm and micro gyroscopes are used. To reduce the errors, three accelerometers can be used. In this case, however, the size and power consumption become too large to use in HMD system. The modified INS algorithm use the grid map and the characteristics of the human motions.

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Adaptive Control for the Conventional Mode of Operation of MEMS Gyroscopes

  • Park, Sungsu;Roberto Horowitz
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.39.2-39
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    • 2002
  • This paper presents adaptive add-on control algorithms for theconventional mode of operation of MEMS z-axis gyroscopes. This scheme is realized by adding an outer loop to a conventional force-balancing scheme that includes a parameter estimation algorithm. The parameter adaptation algorithm estimates the angular rate, identifies and compensates the quadrature error, and may permit on-line automatic mode tuning. The convergence and resolution analysis show that the proposed adaptive add-on control scheme prevents the angular rate estimate from being contaminated by the quadrature error, while keeping ideal resolution performance of a conventional force-balancing scheme.

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Miniaturized gyroscopes using micromachining technology (마이크로머시닝 기술을 이용한 초소형 자이로센서의 연구동향)

  • Han, S.O.;Pak, J.H.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1971-1973
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    • 1996
  • In this paper various types of gyroscope fabricated by micromachining technologies were reviewed. Four common types of gyroscope reported in the past few years are beam, tuning fork, gimbal, and vibrating shell structure made by surface micromachining using sacrificial layer, bulk micromachining using RIE, or electroplating method. In the study of these new gyroscopes, the fabrication methods, advantages and disadvantages of each structure were examined as well as the direction of development in the future.

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The Fiber Optic Gyroscope (I) (광섬유 자이로스코프 (I))

  • 이석정;배정철;홍창희
    • Journal of the Korean Institute of Navigation
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    • v.18 no.4
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    • pp.171-178
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    • 1994
  • Fiber optic gyroscopes must be a promising technology that can replace conventional mechanical ones based on the principle of inertia of spinning masses. The advantages of fiber optic gyroscopes over mechanical ones include low cost, light weight, compact size and fast turn-on time. We will apply them to fiber optic gyrocompass for ships. Fiber optic gyrocompass for ships requires the north-seeking accuracy of $15^{\circ}$/hr, earth rotation rate, or better. This article introduces the fiber optic gyroscope as rotation sensor in the fiber optic gyrocompass system for ships that is planed to develop in our laboratory.

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