• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1429-1432
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• 2005

This work is towards the development of a low-cost, small-sized inertial navigation system(INS) which consists of 3 accelerometers, 3 semiconductor gyros and a magnetic compass sensor. This paper explains in detail the structure of the developed system and proposes a 3 dimensional attitude estimation algorithm with Indirect Kalman Filter. The experiments are performed with the developed system attached to a 6 DOF robot for showing the effectiveness of the algorithm.

• 전기학회논문지
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• 제59권1호
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• pp.82-87
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• 2010

A measurement system of contact force between overhead contact line and pantograph of train is developed which measures the contact force by using four sets of full-bridge strain gauges instead of load cells and accelerometers. The sensors are installed on the pan head of pantograph and the measured data from the sensors are transmitted to a server system in the train by way of wireless Lan. This configuration of the measuring system makes it easy to install on the trains without any alteration of train system. The measurement system is applied to KTX on the Kyungbu high speed line, and the measured contact force data shows good agreement with those measured by load cell and accelerometers. The waveform of the contact force between overhead contact line and pantograph contains essential information about their conditions. The proposed measurement system can probe any defects on overhead contact lines with train running at high speed, which will be a powerful solution for the maintenance of long-distance overhead contact lines.

• Journal of information and communication convergence engineering
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• 제15권3호
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• pp.182-186
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• 2017

Maintaining a proper lookout activity routine is integral to preventing ship collision accidents caused by human errors. Various subjective measures such as interviewing, self-report diaries, and questionnaires have been widely used to monitor the lookout activity patterns of navigators. An objective measurement of a lookout activity pattern classification system is required to improve lookout performance evaluation in a real navigation setting. The purpose of this study was to develop an objective navigator lookout activity classification system using wearable accelerometers. In the training session, 90.4% accuracy was achieved in classifying five fundamental lookout activities. The developed model was then applied to predict real-lookout activity in the second session during an actual ship voyage. 86.9% agreement was attained between the directly observed activity and predicted activity. Based on these promising results, the proposed unobstructed wearable system is expected to objectively evaluate navigator lookout patterns to provide a better understanding of lookout performance.

• 대한기계학회논문집A
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• 제25권9호
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• pp.1410-1415
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• 2001

Active control of sound radiation from a vibrating rectangular plate by a steady-state harmonic point force disturbance is experimentally studied. Structural excitation is achieved by two piezoceramic actuators mounted on the panel. Two accelerometers are implemented as error sensors. Estimated radiated sound signals using vibro-acoustic path transfer function are used as error signals. The vibro-acoustic path transfer function represents system between accelerometers and microphones. The approach is based on a multi-channel filtered-x LMS algorithm. The results shows that attenuation of sound levels of 11dB, 10dB is achieved.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권4호
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• pp.273-279
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• 2002

This paper presents a fabrication technology for the integration of single crystal Si microstructures with on-chip circuitry. It is a dissolved wafer technique that combines an electro-chemical etch-stop for the protection of circuitry with an impurity-based etch-stop for the microstructures, both of which are defined in an n-epi layer on a p-type Si wafer. A CMOS op. amp. has been integrated with $p^{++}$ Si accelerometers using this process. It has a gain of 68 dB and an output swing within 0.2 V of its power supplies, unaffected by the wafer dissolution. The accelerometers have $3{\;}\mu\textrm{m}$ thick suspension beams and $15{\;}\mu\textrm{m}$ thick proof masses. The structural and electrical integrity of the fabricated devices demonstrates the success of the fabrication process. A variety of lead transfer methods are shown, and process details are discussed.

• 한국소음진동공학회논문집
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• 제26권7호
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• pp.827-835
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• 2016

Ride comfort of a vehicle is often determined by rubber bushes in suspension system. If transmission forces versus deformations across the bushes are available under operational conditions, improvement of the ride comfort could be done with more ease. Recently, the transmission forces are measured using custom-made force transducers inside the links. This study presents a feasibility study on estimation of the rubber bush deformations using vibration signals on the rigid links. Linear variable displacement transducers as well as piezoelectric accelerometers are used to expand frequency range to very low frequency, which cannot be done with accelerometers only. How to estimate the bush deformation from the two vibration signals on the links are presented together with experimental results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.875-880
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• 2012

According to the fixation detailed drawing and lightweight anger tendency of the product the vibration control of precision equipments is essential and establishes under the equipments. so It is important to know vibration characteristics of vibration isolator. For this reason the accelerometer attaches in vibration isolator and measures an acceleration response. The acceleration response which is measured will lead double integral and will be able to predict a displacement of vibration isolator. However, in compliance with the effect of the accelerometer can not be accurately. From this paper, mass, damping ratio and natural frequency of the accelerometers by changing the vibration isolator to predict the acceleration response and the results were compared.

• 한국해양공학회지
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• 제11권1호
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• pp.95-105
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• 1997

This paper presents a Inertial Measuring Unit(IMU) for motion measurement of an AUV. The IMU is composed of three parts: inertial sensors with three servo accelerometers and three rate gyros, an analog/digital interface board, and a signal processing board with TMS320C31 DSP processor. The IMU is a class of strap-down inwetial navigation system does not applicable directly to the navigation system in consequence of the AUV and integrated sensors for an integrated navigation system of the AUV. Fast calculstion of direction cosine matrix for the coordinate transformation body to reference is obtained through the DSP processor. A switching algotrithm is used to lessen the low frequency drift effect of the gyros in the vertical plane with use of low pass filtering of the signal of the accelerometers.

• Computers and Concrete
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• 제12권1호
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• pp.79-90
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• 2013

In this study, dynamic characteristics such as natural frequencies, mode shapes and damping ratios of RC frame is determined for different construction stages using Operational Modal Analyses method under ambient vibration. Full scaled, one bay and one story RC frames are selected as an application for different construction stages such as plane, brick in-filled and brick in-filled with plaster. The RC frame is vibrated by natural excitations with small impact effects and the response signals are measured using sensitive accelerometers during ambient vibration tests. Measurement time-frequency span and effective mode number are determined by considering similar studies in literature. Sensitive seismic accelerometers are used to collect signals obtained from the experimental tests. To obtain experimental dynamic characteristics, output-only system identification technique is employed namely; Enhanced Frequency Domain Decomposition technique in the frequency domain. It is demonstrated that the ambient vibration measurements are enough to identify the most significant modes of RC frames.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.608-612
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• 2000

Active control of sound radiation(using active structural acoustic control) from a vibrating rectangular plate by a steady-state harmonic point force disturbance is experimentally studied. Control structural input are achieved by two piezoceramic actuators bonded to the surface of the panel. Two accelerometers are implemented as error sensors. Estimated radiated sound signals using vibro-acoustic path transfer function are used as error signals. The vibro-acoustic path transfer function represents system between accelerometers and microphones. The control approach are based on a multi-channel filtered-x LMS algorithm. The results demonstrate that attenuation of sound levels of 3dB, 13dB are achieved.