• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2665-2667
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• 2004

This paper presents a study of a position finding system for a reactor inspection robot. The position of PSD(Position Sensitive Detector) sensor is calculated by the degree of pan-tilt and the difference in height between pan-tilt and PSD. For that, the DSP which control pan-tilt is used for precise operation and the PIC microcontroller process PSD sensor data that indicate light incident position. A user using computer can acquire the conditions of pan-tilt and PSD.

• 제어로봇시스템학회논문지
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• 제13권7호
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• pp.656-663
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• 2007

A new dynamic balancing algorithm has been proposed to minimize the number of sensors necessary for the horizontal balancing of the mobile inverted pendulum while maintaining the same level of the commercial performance. The inverted pendulum technique is getting attention and there have been many researches on the Segway since the US inventor Dean Kamen commercialized. One of the major problems of the Segway is that many sensors are required for the control of the Segway, which results in the high price. In this research, a single gyro and a tilt sensor are fused to obtain the absolute tilt information, which is applied for the control of the mobile inverted pendulum. A dynamic balancing technique has been developed and applied for a robust control system against disturbances. The intelligent handling and stable curving of the Segway as a next generation mobile tool are verified with a human loading.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.404-408
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• 2009

Gas pipelines in bridges, roads and subway construction sections can undergo abrupt stress and vibration changes. To protect human life from any gas leakage accidents induced by the abrupt stress and vibration, the gas pipeline system needs to be continuously monitored. The estimation method of pipeline stress using MEMS wireless tilt sensor has been developed and its validity has been evaluated using a lab test bench.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.339-341
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• 2006

This paper proposes a method of container position measurement using automatic landing system that is estimated by a laser range finder. In the most of container position measurement methods, CCD cameras or laser scanners have been used to get the source data. However those sensors are not only weak for disturbances, for examples, the light, fog, and rain, but also the system cost is high. When the spreader arrives the goal position, it is still swung by inertia or by wind effect. In this paper, the spreader swung data have been used to find the container position. The laser range finder is equipped in the front side of spreader. It can measure distance and relative position between spreader and container. This laser range finder can be rotated as desired by a motor. And a tilt sensor is equipped on the spreader to measure spreader sway. We estimate the relative position information between the spreader and a container using the laser range finder and tilt sensor through the geometrical analysis.

• 한국산업정보학회논문지
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• 제18권4호
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• pp.19-24
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• 2013

고령화 사회에서는 노인의 신체적 취약성으로 인한 안전문제가 사회문제로 대두되고 있다. 판단, 상황대처 능력이 떨어진 노인은 체력과 균형감각 저하로 인하여 잦은 낙상을 경험한다. 낙상은 자칫 인명피해 및 골절, 유조직 손상 등을 유발 할 수 있으므로 빠른 응급대처가 필요하다. 따라서 본 논문에서는 사용자의 허리에 부착하여 일상적인 움직임에 대한 가속도의 변화 및 낙상이 발생하였을 때의 가속도의 변화를 측정하였다. 측정한 값을 이용하여 낙상 감지 시스템을 구현하였으며, 여러 가지 낙상 상황을 가정하여 낙상 검출 여부를 판별 하였다.

• PNF and Movement
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• 제20권2호
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• pp.215-222
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• 2022

Purpose: The purpose of this study was to compare the effects of passive scapular upward rotation and posterior tilt and active scapular posterior tilt on the muscle activity of the upper trapezius (UT), lower trapezius (LT), and serratus anterior (SA). Methods: Fifteen healthy subjects performed general arm elevation, arm elevation with passive scapular upward rotation and posterior tilt, and arm elevation with active scapular posterior tilt. For active scapular posterior tilt, the subjects were trained in this movement using visual biofeedback and a motion sensor. During each arm elevation condition, electromyography was used to measure the muscle activity of the UT, LT, and SA. The measured data were analyzed using a one-way repeated ANOVA. Results: LT muscle activity was significantly increased during arm elevation with active scapular posterior tilt compared to both general arm elevation and arm elevation with passive scapular upward rotation and posterior tilt (p < 0.05). SA muscle activity was greater during arm elevation with passive scapular upward rotation and posterior tilt than during general arm elevation (p < 0.05). There was no significant change in UT muscle activity among the tested arm elevation conditions (p > 0.05). Conclusion: Performing arm elevation with active scapular posterior tilt and performing arm elevation with passive scapular upward rotation and posterior tilt may be useful strategies for increasing muscle activation of the LT and SA, respectively.

• 한국구조물진단유지관리공학회 논문집
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• 제15권3호
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• pp.116-124
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• 2011

대부분의 구조물 안전성 평가에 있어서 전체적인 거동을 나타내는 인자, 즉 기하학적인 형상 변화를 추정하는 것은 매우 중요하다. 종래에는 현장에서 교량의 처짐을 손쉽게 측정할 수 있는 적절한 수단과 방법의 부재로 말미암아, 처짐의 측정이 제한된 측정점에 국한되었고, 또한 변위계를 설치한 개소에 한정되었다. 따라서, 본 연구에서는 USN(Ubiquitous Sensor Network) 기반의 무선 경사센서모듈(Wireless Tiltmeter)을 통해 건설구조물의 처짐을 추정하는 방법을 개발하고, 기존의 변위 측정 자기 센서(Linear Variable Differential Transformer: LVDT)를 이용해 측정하는 기술 대신, 유비쿼터스 개념의 무선 경사 센서 모듈의 경사 변화에 따른 저항의 변화를 전압의 형식으로 출력하고, 교정계수를 이용하여 실제 처짐각 및 처짐으로 환산하여 최대 처짐을 구하도록 개발된 유비쿼터스 기반의 처짐 추정방법을 검증하기 위하여 실내 실험을 수행하였고, 그 결과, 측정점에 상관없이 균일한 측정이 가능하고, 기존의 방법과 거의 일치하는 값을 나타내는 것으로 확인되었다.

• 천문학회보
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• 제37권2호
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• pp.219.2-219.2
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• 2012

We are developing Adaptive Optics (AO) system for 24 inch telescope at Seoul National University Observatory. It consists of the tip-tilt correction system and the residual wavefront error correction system with a deformable mirror and a wavefront sensor. We present the construction and performance measurements of the tip-tilt correction system. The tip-tilt component is the single largest contributor to wavefront error, especially for small telescope. The tip-tilt correction system consists of a quadrant photodiode, a tip-tilt mirror and a feed back loop. The collimated He-Ne laser beam is used for input light source and is artificially disturbed by air turbulence generated by a heat gun. Most of the turbulence is of low frequency less than 20 Hz, but extends to a few hundreds Hz. It is found that the closed loop system using proportional-integral-derivative (PID) control successfully corrects tip-tilt error at a rate as high as 300~400 Hz.

• 대한조선학회논문집
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• 제47권2호
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• pp.141-149
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• 2010

It is essential to find oscillating angles and periods in a seaway when designing and manufacturing stabilizers. It is difficult to find oscillating angles and periods in high speed turning and they vary with ship speed and wave heading angles, therefore, proper algorithm to measure oscillating periods in a seaway. In the present study, three kinds of algorithms are developed to measure oscillating angles periods in a seaway. Dual axis tilt sensor of low price is used to measure oscillating angles, and the effect of lateral accelerations on tilt sensor have been reduced by the fusion algorithm using the gyro sensor signals. Analog and digital filters are applied to minimize the noise of the signals. Three kinds of algorithms, zero crossing, peak to peak and moving zero crossing algorithm, are developed to measure oscillating periods in a seaway. It is found that the moving zero algorithm showed the best results in the sea trials.

• 조명전기설비학회논문지
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• 제18권6호
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• pp.14-21
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• 2004

본 논문에서는 평지, 오르막 및 내리막에서 야간 운전할 때에 생기는 눈부심에 대해 헤드라이트를 자동 조절하여 운전자가 안전하게 운전을 할 수 있는 알고리즘을 제안하였다. 먼저 광센서를 이용해 전방에 차량이 접근하는지의 유무를 판단하고 기울기센서로써 차량의 기울어진 정도를 계속적으로 판단하도록 하였다. 이러한 정보를 이용하여 헤드라이트를 조절하는 서보모터를 제어함으로써 현 운행환경조건에 맞도록 조절할 수 있도록 하였다. 본 논문에서 제안한 헤드라이트 자동조절시스템은 평지 및 경사로에서 실제로 측정한 조도량에 대한 데이터를 바탕으로 하여 제작되었고, 테스트 모델에 의해 얻은 실험결과를 통해 환경과 조건에 따라 제대로 작동하고 효과가 있음을 확인하였고, 따라서 본 알고리즘의 유효성을 증명하였다.