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Resistive E-band Textile Strain Sensor Signal Processing and Analysis Using Programming Noise Filtering Methods

프로그래밍 노이즈 필터링 방법에 의한 저항 방식 E-밴드 텍스타일 스트레인 센서 신호해석

  • 김승전 (숭실대학교 스마트웨어러블공학과) ;
  • 김상운 (숭실대학교 스마트웨어러블공학과) ;
  • 김주용 (숭실대학교 유기신소재파이버 공학과)
  • Received : 2021.11.23
  • Accepted : 2021.12.28
  • Published : 2022.03.31

Abstract

Interest in bio-signal monitoring of wearable devices is increasing significantly as the next generation needs to develop new devices to dominate the global market of the information and communication technology industry. Accordingly, this research developed a resistive textile strain sensor through a wetting process in a single-wall carbon nanotube dispersion solution using an E-Band with low hysteresis. To measure the resistance signal in the E-Band to which electrical conductivity is applied, a universal material tester, an Arduino, and LCR meters that are microcontroller units were used to measure the resistance change according to the tensile change. To effectively handle various noises generated due to the characteristics of the fabric textile strain sensor, the filter performance of the sensor was evaluated using the moving average filter, Savitsky-Golay filter, and intermediate filters of signal processing. As a result, the reliability of the filtering result of the moving average filter was at least 89.82% with a maximum of 97.87%, and moving average filtering was suitable as the noise filtering method of the textile strain sensor.

ICT 산업의 글로벌 시장을 선점할 수 있는 다음 세대의 개발이 필요한 상황이 일어남에 따라 웨어러블 디바이스의 생체 신호 모니터링에 대한 관심이 크게 증가하고 있다. 이에 따라 본 연구에서는 히스테리시스가 적은 E-Band를 사용하여 단일벽 탄소나노튜브(SWCNT) 분산 용액에 함침 공정을 통해서 저항형 직물 인장 센서(Resistive textile strain sensor)를 개발하였다. 전기전도성이 부여된 e-band에 저항 신호를 측정하기 위해 만능재료시험기(UTM)과 Microcontroller unit인 아두이노와 LCR 미터를 이용해서 인장의 변화에 따른 저항 변화를 측정하였다. 원단으로 이루어진 텍스타일 스트레인 센서의 특성상 발생하는 다양한 노이즈들을 효과적으로 처리하기 위하여 신호처리 과정(Signal processing)의 노이즈 필터링의 이동평균 필터, 사비츠키-골레이 필터, 중앙값 필터들을 사용하여 센서의 필터 성능을 평가하였다. 그 결과 이동평균 필터의 필터링 결과의 신뢰도가 최소 89.82%, 최대 97.87%으로 이동평균 필터링이 텍스타일 스트레인 센서의 노이즈 필터링 방식으로 적합하였다.

Keywords

Acknowledgement

이 논문은 2021년도 산업통산자원부 및 산업기술평가관리원(KEIT) 연구비 지원에 의한 연구임('20016038'). 이 논문은 산업통산자원부 '산업혁신인재성장지원사업'의 재원으로 한국산업기술진흥원(KIAT)의 지원을 받아 수행된 연구임(P002397).

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