• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.910-912
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• 2015

본 논문에서는 중장비나 댐의 수문 등의 적용된 유압 실린더의 변위(stroke)를 검출하여 유압 실린더의 정밀제어 또는 자동화를 위한 정전용량 센서(Capacitive Sensor) 및 변위 검출 시스템을 설계하였다. 기존 실린더의 변위 검출 방식인 코일을 이용한 자기장 센서, LVDT 센서 등은 높은 정확도에 비해 충격 및 진동 완화 또는 센서 보호 하우징(Housing) 등 부수적인 설비에 따른 높은 비용, 큰 부피와 같은 문제가 있다. 따라서 이러한 개선하기 위해 유압 실린더 내의 직접 적용되어 실린더의 변위 검출이 가능한 정전용량 센서를 설계하였으며, 설계한 정전용량 센서를 통하여 실린더의 변위에 따른 커패시턴스 값을 검출하여 실린더 위치 측정이 가능한 시스템을 설계 및 검증 하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.2061_2062
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• 2009

Within serviced period of time in transformer, thermal stress is the most influential parameter affecting the aging behavior of an insulation system. The thermal stress on the insulation system may occur from operation in a high temperature environment due to Joule's heat at winding coils. This paper describes a development of capacitive sensor and preventive diagnosis techniques for electrical insulating oil, widely used for power and distribution transformer. To survey the dielectric properties of the virgin and used mineral insulating oil, we utilized the highly precise measuring system of KRISS. And the results were used to determine the design factors of the sensor. To evaluate diagnosis by the sensor, we performed accelerated aging test about insulating oils. The condition of aged specimens were investigated by measurements of relative permittivity i.e. capacitance change by capacitive sensor.

• 대한기계학회논문집A
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• 제33권9호
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• pp.976-981
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• 2009

MEMS capacitive gap sensor is developed for measuring abrasion depth of gun barrel rifling. Measuring abrasion depth of gun barrel rifling is very important because it is related with exactness of firing and life of arms. The method using a gap sensor is not to hurt rifling. And it can measure abrasion depth through minimum shooting, because the developed gap sensor can measure from $1{\mu}m{\sim}12{\mu}m$ using Polydimethylsiloxane(PDMS) material and making a stretchable electrode on PDMS. And it's resolution is 1 ${\mu}m$ using capacitive method and MEMS technology.

• 한국전기전자재료학회논문지
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• 제27권9호
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• pp.566-570
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• 2014

Electrode pattern effects on the capacitive humidity sensor were investigated. The fabrication of the capacitive humidity sensor was formed with three steps. The bottom electrode was formed on the silicon substrate with Pt/Ti thin layer by using shadow mask and e-beam evaporator. The photo sensitive polyimide was formed on the bottom electrode by using photolithography process as a humidity sensitive thin film. The upper electrode was formed on the polyimide thin film with Pt/Ti thin layer by using e-beam evaporator and lift-off method. Three electrode patterns, such as circle, square, and triangle pattern, were used and changed the sizes to investigate the effects. The capacitances of the sensors were decreased 622 to 584 pF with the area decreament of patterns 250,000 to $196,250{\mu}m^2$. From these results, a capacitive humidity sensor with photo sensitive polyimide is expected to be applied to a high sensitive humidity sensor.

• 전기학회논문지
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• 제57권10호
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• pp.1861-1868
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• 2008

In this paper, Passive Telemerty RF Sensor System using Unscented Kalman Filter algorithm(UKF) is proposed. General Passive Telemerty RF Sensor System means that it should be "wireless", "implantable" and "batterless". Conventional Passive Telemerty RF Sensor System adopts Integrated Circuit type, but there are defects like complexity of structure and limit of large power consumption in some cases. In order to overcome these kinds of faults, Passive Telemetry RF Sensor System based on inductive coupling principle is proposed in this paper. Because passive components R, L, C have stray parameters in the range of high frequency such as about 200[KHz] used in this paper, Passive Telemetry RF Sensor System considering stray parameters has to be derived for accurate model identification. Proposed Passive Telemetry RF Sensor System is simple because it consists of R, L and C and measures the change of environment like pressure and humidity in the type of capacitive value. This system adopted UKF algorithm for estimation of this capacitive parameter included in nonlinear system like Passive Telemetry RF Sensor System. For the purpose of obtaining learning data pairs for UKF Algorithm, Phase Difference Detector and Amplitude Detector are proposed respectively which make it possible to get amplitude and phase between input and output voltage. Finally, it is verified that capacitive parameter of proposed Passive Telemetry RF Sensor System using UKF algorithm can be estimated in noisy environment efficiently.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1117-1118
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• 2011

• 한국정밀공학회지
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• 제22권6호
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• pp.30-39
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• 2005

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.841-842
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• 2011

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1103-1104
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• 2011

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 추계학술대회 논문집
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• pp.537-537
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• 2010

High precision sensing is very important in various technologies. Especially, it is more important when it were applied to nano/micro meter level's sensing like AFM, storage, etc. And capacitive sensing is widely used method. To improve the measurement efficiency, many signal conditioners were studied and one of them was surface acoustic wave (SAW) device. SAW device is very widely used as a high frequency bandwidth filter. Due to the reflective characteristic of high frequency, the response of SAW device contains both propagative and reflective signal at the external impedance. In this paper, we used SAW device as signal conditioner of capacitive sensor. And high precision gap measurement was executed using capacitive load. Reference signal was reflective SAW response and the magnitude at the center frequency of SAW device by the change of impedance was checked. Finally, the attainable gap resolution was determined.