• Title/Summary/Keyword: 비접촉 진동 측정

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Vibration Measurement of an Automobile Exhaust System in Operation (구동중인 자동차 배기계의 진동 특성 측정)

  • Kim, Sung-Kook;Lee, Jong-Nam;Han, Soon-Woo;Chung, Tae-Jin;Lee, Sin-Young;Jang, Gang-Won
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.3 s.120
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    • pp.235-240
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    • 2007
  • In this work, the operational deflection shape(ODS) of an automobile exhaust system is measured by using a recently-developed magnetic sensor. The magnetic sensor is composed of a solenoid and two pairs of permanent magnets generating an antisymmetric magnetic field in the lateral direction inside the solenoid. Lateral movement of a ferromagnetic pipe inside the magnetic field of the suggested sensor induces an electromotive force in the solenoid corresponding to the lateral velocity of the pipe. Due to the simplicity and non-contact characteristics of the magnetic sensor, dynamic behaviors of the structures operating under high temperature such as an exhaust pipe can be efficiently observed. It is shown that the lateral ODS of an exhaust system can be successfully measured by the suggested sensors.

광 간섭 계측

  • Korea Optical Industry Association
    • The Optical Journal
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    • s.104
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    • pp.70-74
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    • 2006
  • 일반적으로 광 간섭 계측은 비접촉, 고감도, 면계측, 내전자(耐電磁) 노이즈 등 다른 계측방법에는 보이지 않는 우수한 장점을 가지고 있는 반면, 공기 흔들림이나 외부 진동 등의 외란에 약하여 광학 조정이 번거로우며 측정 범위가 좁다는 문제점도 있어, 아직까지는 산업적으로 충분히 보급되고 있지 않은 것이 현실이다. 여기서는 옵토 메카트로닉스 기술로서의 광 간섭 계측 기술이 상기 문제점을 극복하면서, 앞으로 어떻게 발전해 나갈 것인 지를 예측하여 기술 로드맵의 작성을 시도하였다. 기술 로드맵은 반도체 산업에서는 본격적인 것으로 정평이 나있지만, 광 간섭 계측 기술에 대한 것은 거의 없다. 따라서, 여기서 채택한 기술과 그 미래에 대해서는 필자의 경험과 주관이 상당히 많이 개입되어 있음을 미리 말해 둔다.

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Computational Modelling Method by Using the Natural Frequencies of Five-Story Stone Pagoda in Chongnimsa Site (고유진동수를 이용한 정림사지 5층 석탑의 구조모델)

  • Lee, Sung-Min;Lee, Ki-Hak;Park, Sun-Woo;Suh, Man-Chul;Lee, Chan-Hee
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.5
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    • pp.67-74
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    • 2008
  • Multi-layered stone masonry monuments, such as stone pagoda can be modeled as a multi-degrees of freedom system. The dynamic behavior of these structures are mainly influenced by contour condition of contacting surface of stones. In this case the mass of the system can be easily estimated, mean while the estimation of stiffness at junction is not simple. In this paper a method for estimating the spring constant at the contacting surface of stone in proposed. This paper describes a method of computational modelling technique for structural analysis of stone pagodas using measurement of natural frequency and eigenvalue analysis. For this purpose Five story stone pagoda in Cchongnimsa site was selected as a model.

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Noncontact optical system for measurement of displacement and vibration (미소 변위 진동측정을 위한 광학 시스템 설계 및 제작)

  • Hwang, Woong;Kwon, Jin-Hyuk
    • Korean Journal of Optics and Photonics
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    • v.14 no.3
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    • pp.260-265
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    • 2003
  • A noncontact optical system that can measure displacement or vibration of an object is designed by employing the oblique ray method. By using a single convex lens which serves as both the input and output lenses, we made the optical system very compact and reliable. In addition, the bandwidth of the vibration measurement is more than 100 KHz by using the position-sensitive detector as the beam position sensor. The resolution and capture range of the system are $\pm$1 ${\mu}{\textrm}{m}$ and 1100 ${\mu}{\textrm}{m}$, respectively. As a sample test, the vibrations of a speaker and a rotating compact disc surface were measured.

Measurement of Liquid Oscillation in Tuned Liquid Dampers using a Laser Doppler Vibrometer (레이저진동계를 사용한 동조액체댐퍼의 액체 진동 측정)

  • Shin, Yoon-Soo;Min, Kyung-Won;Kim, Junhee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.6
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    • pp.513-519
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    • 2016
  • In this study, dynamic vertical displacement of liquid in the tuned liquid column damper(TLCD) is measured by a laser Doppler vibrometer(LDV) to overcome limitations of existing sensors and to leverage noncontact sensing. Addressing advantages of noncontact measurements, operational principles of the LDV to measure velocity and displacement of a target object in motion is explained. The feasibility of application of the LDV to measurement of liquid motion in the TLCD is experimentally explored. A series of shake table tests with the TLCD are performed to determine requirements of application of the LDV. Based on the experimental results, it is proved that the LDV works under the condition of adding dye to the liquid by increasing the intensity of reflected laser and thus validity is verified by comparison with a conventional wave height meter.

A Development of Wireless Monitoring System for Temperature Monitoring by using IR Sensor (적외선 센서를 이용한 열화상태 무선감시 시스템 개발)

  • Kim, Jihee;Kim, Sinwoo;Kang, Yongsoo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.1
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    • pp.239-245
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    • 2013
  • The temperature monitoring of power cable and cable junction point is the necessary link of the safe and reliable operation of the power system. Many kinds of cables and high voltage junction points are easy to exposed continuous vibrations and momentary impulse in industry field especially power plant industries. This system can predict the overheating of the electric cable interface and the possibility of all kinds of accident, and it helps for eliminating the hazards of electric cable interface and provides the effective guarantee for the safety operation. In order to avoid the faults of the inconvenience of installation and maintenance and the high cost of application, this system used small and contactless IR sensor module. The low power consumption is used in the system. The goal of this study is the low cost and on-line reliable monitoring of power cable and junction point temperature.

Non-Contact Measurement of Elastic Waves Propagating in a Rotating Shaft using Magnetostrictive Effects (자왜 현상을 이용한 회전축 내부의 비접촉 탄성파 측정)

  • 한순우;이호철;김윤영
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11a
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    • pp.365-370
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    • 2001
  • The purpose of this work is to suggest a new non-contact measurement method applicable to the diagnosis of rotating shafts. Longitudinal elastic waves propagating along the shafts are measured by magnetostrictive sensors that make use of the coupling phenomena between strains and magnetic induction in ferromagnetic shafts. These sensors have been successfully applied in pipes and others, but it appears that the present application of them to rotating shafts is made here for the first time. Several isssues appearing in the present application are carefully investigated and several experimental results are presented to address the usefulness of the present method.

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Development and Experimentation of a Non-Contact Magnetostrictive Sensor for the Elastic Wave Mode Selection (탄성파의 선택적 측정을 위한 비접촉 마그네토스트릭션 센서의 개발 및 실험적 검증)

  • 김영규;이호철;김윤영
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.549-553
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    • 2002
  • Although the magnetostrictive sensors have received much attention in recent years. the investigations on the selection of a desired mode have not been reported. The purpose of this investigation is to present a technique to select a desired mode in a solid ferromagnetic cylinder using a non-contact magnetostrictive sensor. To achieve this goal. we propose new bias magnet configurations to select longitudinal and flexural waves. A few experimental results confirm the validity of the present investigation.

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Development of an Elastic Wave Sensor Including Rotary-encoding Capability (회전속도 측정 기능을 포함한 비접촉 탄성파 센서의 개발)

  • Lee, Ho-Cheol;Kim, Myong-Ho;Park, Jung-Yang
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.05a
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    • pp.143-146
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    • 2006
  • In this paper, a hybrid sensor is proposed that has two capabilities: The first is to sense longitudinal of flexural elastic waves selectively which are transmitted along the targe shaft, the second to measure the rotating speed of the shaft. All measurement are made in a noncontact manner since this sensor uses magnetostriction as its measuring principles. Furthermore, the switching between these two sensing capabilities are accomplished by a very simple mechanical operation. To verify the capabilities of the Proposed sensor, an Prototype sensor are fabricated and the experiments are made. The result shows this sensor can embody two sensing capabilities in one sensor configuration.

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A Study on the Correlation Analysis of EEG and Vibraimage due to Auditory and Olfactory Stimulation (청각 및 후각자극에 의한 뇌파(EEG)와 진동이미지기술의 상관성 분석에 관한 연구)

  • Kim, Jung-Min;Kim, Myung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4291-4297
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    • 2015
  • EEG has been used to measure the emotion of amenity and discomfort in the interior space. EEG is limited to the experiment, because it is a equipment of contact type. However, Vibraimage can measure the emotion with a web camera. Because Vibraimage is a equipment of non-contact type, it is more suitable for the interior space than EEG. Therefor, it tries to find a correlation variable between EEG and Vibraimage to measure the human emotions. In this study, it were analyzed correlation of EEG and vibraimage due to variation of loudness 60[dB], 90[dB] and rosemary, jasmine scents. Check the health status of subjects who were selected 3 male students, and the period of this experiment was about months. The condition of the environmental test room was in temperature 25[$^{\circ}C$], relative humidity 50[RH%], air current speed 0.02[m/s] and illuminance 1000[lux]. It were analyzed correlation of twenty-three index of EEG(absolute ${\theta}$, relative ${\theta}$, absolute $S{\alpha}$, relative $S{\alpha}$, absolute ${\alpha}$, relative ${\alpha}$, absolute ${\beta}$, relative ${\beta}$, absolute $\gamma$, relative $\gamma$, absolute $F{\alpha}$, relative $F{\alpha}$, absolute SMR, relative SMR, $SMR/{\theta}$, $SMR+M{\beta}/{\theta}$, absolute $H{\beta}$, relative $H{\beta}$, $H{\beta}/{\alpha}$, absolute $M{\beta}$, relative $M{\beta}$, SEF50, ASEF50) and ten index of Vibraimage(Aggression, Stress, Tension/Anxiety, Suspect, Balance, Charm, Energy, Self regulation, Inhibition, Neuroticism). As a result, I was found that relative ${\gamma}$ index of EEG and neuroticism index of Vibraimage have a high correlation as (${\pm}$).414 and (${\pm}$).424.