• Title/Summary/Keyword: Accelerometer Resonance

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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

Influence of Effective Piezoelectric Properties on Performance of Piezoelectric Accelerometer for Vibration Measurements (진동 측정용 압전형 가속도센서의 압전특성 효과)

  • 권정락
    • Journal of the Korean Ceramic Society
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    • v.32 no.8
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    • pp.945-949
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    • 1995
  • In order to investigate the performance of compression-type accelerometer on piezoelectric properties, PZT materials have been studied. The ring-shaped piezoelectric elements were prepared using commercial PZT powders by conventional ceramic process. Their estimated relative dielectric constant, piezoelectric charge constant (d33) and voltage constant (g33) values showed 390∼3400, (90∼593)×10-12 C/N and (19.5∼40.5)×10-3 V-m/N, respectively. The charge sensitivity of accelerometer is proportional to the piezoelectric charge constant value (d33) of PZT, but its voltage sensitivity is related with the piezoelectric voltage constant (g33). Since the mounted resonance frequency and sensitivity are dependent on the seismic mass as well as physical charateristics and size of PZT elements, the suitable considerations between two components are required for accelerometer's design.

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Fiber-optic interferometric accelerometer using silicon micromachining. (실리콘 마이크로머시닝을 이용한 광섬유 간섭계형 가속도 센서)

  • 권혁춘;김응수;김경찬;강신원
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.02a
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    • pp.322-323
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    • 2003
  • Silicon substrate was fabricated by bulk silicon micromachining and it's structure is based on a proof mass suspended by two beam. To monitor the acceleration, dynamic excitation of accelerometer was performed using a shaker. The attached FFPI and suspension beam are bent because support beam move with variation of the proof mass. Thus phase difference detected by the acceleration change. So we can know that resonance frequency of fabricated accelerometer is about 557 Hz and dynamic range was measured from 0 g to 2 g.

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Study on improvement of frequency response characteristics of accelerometer (진동가속도계의 주파수응답특성 개선에 관한 연구)

  • 한응교;조진호
    • Journal of the korean Society of Automotive Engineers
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    • v.3 no.1
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    • pp.61-68
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    • 1981
  • There are three types in frequency response accelerometer; one is lightly damped piezp type, another is oil damping stainguage type and the third is electro induction type accelerometer within electromagnetic damping. The usable frequency range of lightly damped accelerometers is limited to 0.2 of their mounted natural frequency for amplitude distortion of less than 5 percents. There have been situation where the measured motion contains unforeseen high - frequency components, which are regarded as such due to the accelerometer transfer function. There are several way to overcome amplitude distortion of the higher than anticipated frequency components; (I) to make use of the accelerometer with natural frequency three times and more as high as the measured frequency, (II) to establish data-analysis techniques which will account for the amplitude distortion, (III) to set up a notch filter circuit which has a transfer function that is the reciprocal of the accelerometer transfer function, and so on. This paper makes a report of the method as to(III), i. e., set up a few notch filter circuits, it is discussed what happens when the transfer functions, are in discord as to natural frequency of the filter and accelerometer damping vs. filter damping. And especially as for the cantilever strain gauge type accelerometer made by oneself with ease, it was compared and discussed between the ideological value and the experimental value of actual designed circuit in case of the mismatching of the transfer functions, and it was considered whether to be practicable or not, the result of which was as following; the useful frequency range of the accelerometer can be extended to near resonance if (a) the accelerometer mounted natural frequency and the filter center frequency are matched within .+-. 2 percent and (b) the damping ratios are matched within two factors. Therefore, we obtained the good result in improvement for extending frequency response characteristics of accelerometer.

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Resonant Loop Design and Performance Test for a Torsional MEMS Accelerometer with Differential Pickoff

  • Sung, Sang-Kyung;Hyun, Chul;Lee, Jang-Gyu
    • International Journal of Control, Automation, and Systems
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    • v.5 no.1
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    • pp.35-42
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    • 2007
  • This paper presents an INS(Inertial Navigation System) grade, surface micro-machined differential resonant accelerometer(DRXL) manufactured by an epitaxially grown thick poly silicon process. The proposed DRXL system generates a differential digital output upon an applied acceleration, in which frequency transition is measured due to gap dependent electrical stiffness change. To facilitate the resonance dynamics of the electromechanical system, the micromachined DRXL device is packaged by using the wafer level vacuum sealing process. To test the DRXL performance, a nonlinear self-oscillation loop is designed based on the extended describing function technique. The oscillation loop is implemented using discrete electronic elements including precision charge amplifier and hard feedback nonlinearity. The performance test of the DRXL system shows that the sensitivity of the accelerometer is 24 Hz/g and its long term bias stability is about 2 mg($1{\sigma}$) with dynamic range of ${\sigma}70g$.

Novel graphene-based optical MEMS accelerometer dependent on intensity modulation

  • Ahmadian, Mehdi;Jafari, Kian;Sharifi, Mohammad Javad
    • ETRI Journal
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    • v.40 no.6
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    • pp.794-801
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    • 2018
  • This paper proposes a novel graphene-based optical microelectromechanical systems MEMS accelerometer that is dependent on the intensity modulation and optical properties of graphene. The designed sensing system includes a multilayer graphene finger, a laser diode (LD) light source, a photodiode, and integrated optical waveguides. The proposed accelerometer provides several advantages, such as negligible cross-axis sensitivity, appropriate linearity behavior in the operation range, a relatively broad measurement range, and a significantly wider bandwidth when compared with other important contributions in the literature. Furthermore, the functional characteristics of the proposed device are designed analytically, and are then confirmed using numerical methods. Based on the simulation results, the functional characteristics are as follows: a mechanical sensitivity of 1,019 nm/g, an optical sensitivity of 145.7 %/g, a resonance frequency of 15,553 Hz, a bandwidth of 7 kHz, and a measurement range of ${\pm}10g$. Owing to the obtained functional characteristics, the proposed device is suitable for several applications in which high sensitivity and wide bandwidth are required simultaneously.

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.

The Effect of Train Motion on Current Collection in High-speed Train

  • Kim, Jung-Soo
    • International Journal of Safety
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    • v.5 no.1
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    • pp.1-4
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    • 2006
  • The safety performance of the current collection system is evaluated by conducting a test run in which accelerometer and load cell signals are analyzed. It has been found that the current collection performance is strongly influenced by the train speed, with the major frequency components arising from the train traversing the span spacing and the 8.5 Hz component originating from the panhead resonance. The train acceleration is found to have significant influence on the span passing frequency but negligible effect on the resonant response.

A Case Study of the Higher Vibration on the Driving Motors of Port Crane (항만용 크레인 구동 모터 고진동 사례 연구)

  • Kim, Yeong-Chun;Park, Heui-Joo
    • Proceedings of the KSME Conference
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    • 2001.06b
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    • pp.416-421
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    • 2001
  • It was firstly issued that frequently broken of Encoder installed at travelling motor during RTGC operation. Estimated as broken due to excessive vibration of traveling and motor manufacturer claimed it as resonance of motor base. The principal vibration of Encoder was caused by the rotating vibration component of motor and by traveling wheel. The component transmitted from the wheel didn't have great vibration by the resonance with motor and other parts. Therefore, the plans was tried to add the support point to prevent the Encoder shaft vibrated greatly and inhibit the vibration. These showed good results.

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Fabrication and Characteristics Comparison of Piezoresistive Four Beam Silicon Accelerometer Based on Beam Location (빔 위치변화에 따른 4빔 압저항형 실리콘 가속도 센서의 제조 및 특성비교)

  • Shin, Hyun-Ok;Son, Seung-Hyun;Choi, Sie-Young
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.36D no.7
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    • pp.26-33
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    • 1999
  • In order to examine the effect of beam location n the performance of bridge type piozoresistive silicon accelerometer, three sensors having different location of beams were simulated by FEN(finite element method) and fabricated by RIE(reactive ion etching) and KOH etching method using SDB(silicon direct bonding) wafer, Results of the FEM simulation present that the 1st resonace frequency and Z axis sensitivity of each sensor are identical but the 2nd, and the 3rd resonace frequency and X, Y axis sensitivity are different. Even though the 1st resonance frequency and Z axis sensitivity measured from fabricated sensors do not perfectly coincide with each other, all 3 type sensors present 180 ~ 220N/G of Z sensitivity at 5 V supply voltage and 1.3 ~ 1.7kHz of the 1st resonance frequency and about 2% of lateral sensitivity.

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