• Title/Summary/Keyword: 가속도계 공진

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Electromechanical Modeling and Experimental Verification of Differential Vibrating Accelerometer (차분 진동형 가속도계 전기적 모델링 및 실험적 검증)

  • Lee, Jung-Shin;Rhim, Jae-Wook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.6
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    • pp.517-525
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    • 2011
  • Differential Vibrating Accelerometer(DVA) is a small and accurate resonant device to sense the change in natural frequency in presence of acceleration input. Both mathematical modeling for the electromechanical dynamics and experimental investigation on the structural characteristics are necessary for effective designs of precision controller and high Q-factor structure. In this paper, electromechanical modeling of the resonator of DVA, electrode module, and pre-amplifier is presented. The presented method is experimentally verified by measuring the resonance frequency, effective mass, effective stiffness and Q-factor. The direct comparison of the calculated displacement and the actual pre-amplifier of DVA also indicates the effectiveness of this study.

Oscillation Amplitude-controlled Resonant Accelerometer Design using Aautomatic Gain Control Loop (자동이득 제어루프를 이용한 진폭제어방식의 공진형 가속도계 설계)

  • Yun, Suk-Chang;Sung, Sang-Kyung;Lee, Young-Jae;Kang, Tae-Sam
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.7
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    • pp.674-679
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    • 2008
  • In this paper, we introduce a new design approach for self-sustained resonant accelerometer, that takes advantage of the automatic gain control (AGC) loop to achieve a stabilized oscillation dynamics. Fundamental idea of this accelerometer is to maintain uniform amplitude of oscillation under input accelerations. Through system modeling and loop transformation considering the envelope of oscillation, the controller is designed to maintain uniform amplitude in oscillation under dynamic input acceleration. The simulation results demonstrate the feasibility of the proposed accelerometer design, which is applicable to control grade inertial measurement system in industrial and civil application fields.

압전형 가속도계의 설계, 제작 및 보정 II - 개발 연구 사례를 중심으로 -

  • 이종원;구경회
    • Journal of the KSME
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    • v.29 no.4
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    • pp.414-425
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    • 1989
  • 본 연구를 통하여 원하는 감도와 부착 공진 주파수가 주어질 때 실제로 이러한 성능을 갖는 압 축식 압전형의 가속도계를 이론적으로 설계하여 제작할 수 있었으며 보정 실험을 통하여 실험 가속도계는 실제 설계값에 가까운 성능을 나타내었다. 설계, 제작된 실험 가속도계의 특성 실 험을 통하여 다음과 같은 결론을 얻었다. (1) 가속도계의 감도는 압전 소자의 압전 상수가 일 정할 때 관성 질량에 따라서만 지배되는 것이 아니라 압전 소자의 크기에 따라서도 달라진다. (2) 높은 감도의 가속도계를 설계하기 위해서는 단일 압축식의 설계보다는 이중 압축식의 설계를 행하는 것이 바람직하며 감도가 큰 가속도계 일수록 0.1g 이하의 낮은 가진 레벨에서의 특성도 아주 좋다. (3) 높은 주파수에서의 특성이 좋은 가속도계를 설계하기 위하여서는 단일 압축식 으로 설계하는 것이 좋으며 압전 소자의 두께는 얇은 것이 좋다. (4) 압전 소자와 관성 질량의 접착시에 전도성 접착제를 사용하지 않아도 기포를 제거한 양호한 에폭시계통의 접착제를 사용 하여 접착층의 두께를 최대한 얇게 하면 설계값에 가까운 감도를 가진 가속도계를 제작할 수가 있다.

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Design and Fabrication of a Mass-spring System for the Force-balance Servo Accelerometer (힘평형 서보 가속도계의 질량지지 장치 설계 및 제작)

  • Kim, Young-Dam;Go, Young-Jun;Nam, Hyo-Duk;Lee, Doo-Hee;Chang, Ho-Gyeong
    • The Journal of the Acoustical Society of Korea
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    • v.20 no.5
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    • pp.14-20
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    • 2001
  • The mass-spring system with four arms for the force-balance servo accelerometer was designed and fabricated. The response characteristics of a mass-spring system was calculated with the change of arms thickness and seismic mass by the finite element method (FEM). Furthermore, the response characteristics of accelerometer was measured using the change of interference pattern and response voltage value by Michelson interferometer. The response characteristics with changing length and thickness of arm was changed drastically, and changing seismic mass was minor effect for the response characteristics of mass-spring system. The measured resonant frequencies have good agreement with that of numerical analysis within 5% range.

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Self-Alignment/Navigation Performance Analysis in the Accelerometer Resonance State Generated by Dither Motion of Ring Laser Gyroscope in Laser Inertial Navigation System (레이저 관성항법장치에서 링레이저 자이로 디더 운동에 의한 가속도계 공진이 자체 정렬/항법 성능에 미치는 영향 분석)

  • Kim, Cheonjoong;Lim, Kyungah;Kim, Seonah
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.6
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    • pp.577-590
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    • 2021
  • In this paper, we theoretically analyzed the self-alignment/navigation performance in the accelerometer resonance state generated by dither motion of ring laser gyroscope in LINS and verified it through simulation. As a result of analysis, it is confirmed that the amplitude of the accelerometer measurement amplified in the accelerometer resonance state is decreased in the process of sampling per the navigation calculation period and that frequency is changed by the aliasing effect too. It was also analysed that the attitude error in self-alignment is determined by the amplitude/frequency of the accelerometer measurement, the gain of the self-alignment loop, and the velocity and position error in the navigation is determined by the amplitude/frequency/phase error of the accelerometer measurement. This analysis and simulation results show that the self-alignment and navigation performance is not be degraded only when the amplification factor of the accelerometer measurement in the accelerometer resonance state is 3 or less

Fault Detection Method of Laser Inertial Navigation System Using FFT (FFT를 이용한 레이저 관성항법장치 고장검출 기법)

  • Yoo, Hae-Seong;Kim, Cheon-Joong
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.5
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    • pp.502-510
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    • 2009
  • Laser Inertial Navigation System(LINS) consists of Ring Laser Gyroscopes(RLG) and accelerometers. RLG has a lock-in region in which there is zero output for input angular rates less than 0.1deg/sec. The lock-in region is generated by the imperfect mirrors in RLG. To avoid the lock-in region, sinusoidal motion which is called dither motion is applied on RLG. Therefore without the fault in LINS, the dither motion must be measured by RLG/accelerometer. In this paper, we propose the method to detect the fault of LINS through checking out whether or not the dither motion is always measured by RLG/accelerometer using the Fast Fourier Transformation(FFT) on the real time. The feasibility of the fault detection method proposed in this paper is verified through the stationary and van test.

Study on the Calibration of a ICP Type Bite-bar designed to measure head vibration (머리진동측정용 ICP형 바이트-바(Bite-bar)의 교정방법에 관한 연구)

  • 최병재;정완섭;홍동표
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.760-763
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    • 2002
  • 본 논문은 인체의 머리진동 측정용 Bite-bar에 관한 연구이며, 머리진동의 관심주파수 영역인 0.5∼30Hz 범위의 주파수 범위에서 ICP형 가속도계를 이용한 바이트-바(Bite-bar)의 공진특성에 관한 실험결과와 공진특성의 보상 방법에 관해 기술하고 있다. 또한 바이트-바(Bite-bar)의 회전비교교정에 관한 방법과 절차 그리고 실험결과를 제시하고 바이트-바(Bite-bar) 교정의 중요성과 오차(error)와 설계 제작에 있어서의 주의사항에 관해 간략히 소개한다.

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Design, Fabrication, Static Test and Uncertainty Analysis of a Resonant Microaccelerometer Using Laterally-driven Electrostatic Microactuator (수평구동형 정전 액추에이터를 이용한 금속형 공진가속도계의 설계, 제작, 정적시험 및 오차분석)

  • Seo, Yeong-Ho;Jo, Yeong-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.3
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    • pp.520-528
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    • 2001
  • This paper investigates a resonant microaccelerometer that measures acceleration using a built-in micromechanical resonator, whose resonant frequency is changed by the acceleration-induced axial force. A set of design equations for the resonant microaccelerometer has been developed, including analytic formulae for resonant frequency, sensitivity, nonlinearity and maximum stress. On this basis, the sizes of the accelerometer are designed for the sensitivity of 10$^3$Hz/g in the detection range of 5g, while satisfying the conditions for the maximum nonlinearity of 5%, the minimum shock endurance of 100g and the size constraints placed by microfabrication process. A set of the resonant accelerometers has been fabricated by the combined use of bulk-micromachining and surface-micromachining techniques. From a static test of the cantilever beam resonant accelerometer, a frequency shift of 860Hz has been measured for the proof-mass deflection of 4.3${\pm}$0.5$\mu\textrm{m}$; thereby resulting in the detection sensitivity of 1.10${\times}$10$^3$Hz/g. Uncertainty analysis of the resonant frequency output has been performed to identify important issues involved in the design, fabrication and testing of the resonant accelerometer.

An Analysis of the Vibration Characteristics through the Human Body (인체 내부에서의 진동 전달특성 분석)

  • 전종원;진용옥
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.7
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    • pp.59-65
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    • 2000
  • This paper describes the analysis of vibration characteristics through the human body as the research for voice therapy and diagnosis. The oscillation signal is not external forces but the self-voice to be pronounced the vowels ('a', 'e', 'i', 'o', 'u'). The experiment system consists of microphones, accelerometers and amplifiers. The input data are stored by the computer. At the same time, the voice is stored by the microphone and the vibration signal of the human body is stored by accelerometer. The 63 points are appointed in head, neck, trunk of human body. The positions and number of times are changeable by the purpose. The analysis parameters are amplitude, phase, fundamental. frequency, formant and the correlation of vibration signal and voice is measured by coherence function. The results show that the vibration signals have characteristic vibration in the positions of human body.

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A Study on a Silicon Resonator for Piezoresistive Accelerometer (압전저항 가속도계를 위한 실리콘 공진자에 관한 연구)

  • Yang, Eui-Hyeok;Yang, Sang-Sik
    • Proceedings of the KIEE Conference
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    • 1991.11a
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    • pp.274-277
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    • 1991
  • A piezoresistive silicon resonator which can be used as an accelerometer is designed and fabricated using silicon micromachining techniques. The device consists of a seismic mass and four deflection beams in which eight piezoresistors are diffused. The structure is fabricated by EPW etching process. The piezoresistors are properly arranged and connected to make a bridge circuit, with which acceleration in only one direction can be measured. According to the experimental results, the first resonant frequency of this resonator is above 15 kHz, and this transducer has a sensitivity of 5.56 ${\mu}V/Vg$.

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