Journal of the Korea Institute of Information and Communication Engineering (한국정보통신학회논문지)

The Korea Institute of Information and Commucation Engineering (한국정보통신학회)
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Implementation of Capacitance Measurement Equipment for Fault Diagnosis of Multi-channel Ultrasonic Probe

다중채널 초음파 프로브 고장진단을 위한 커패시턴스 측정 장치 구현

  • Kang, Bub-Joo (Department of Information & Communication Engineering, Dongguk University at Gyeongju) ;
  • Kim, Yang-soo (Department of Electronic Engineering, Kumoh National Institute of Technology)
  • Received : 2015.09.29
  • Accepted : 2015.11.06
  • Published : 2016.01.31
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Abstract

In this paper, we propose the method to measure the capacitances using not LCR meter but capacitance to voltage(C/V) conversion. And we design the analog MUX circuits that convert 192 channels to 6 MUX channels in order to implement the diagnosis of multi-channel ultrasonic probe. This paper derives the conversion function that converts the digital voltage of each MUX channel to the capacitance using the least squares method because the circuit characteristics that convert the voltage of each MUX channel to the capacitance are different. The developed prototype illustrates the performance test results that the measure times are measured by within 4sec and the measure error rates of maximum, minimum, and average values are within 5% in terms of the repeated measurements of all 192 channels.

본 논문에서는 기존의 LCR 미터에 의한 측정방식이 아니라 C/V(capacitance to voltage) 변환 방식을 이용하여 커패시턴스를 측정하는 방법을 제안하였다. 그리고 다중채널용 초음파 프로브 진단장치를 구현하기 위해 192채널들을 6개의 MUX(multiplexer) 채널로 변환하는 아날로그 MUX 회로를 설계하였다. 각각의 MUX 채널 회로별 전압을 다시 커패시턴스로 변환하는 회로특성이 다르기 때문에 각각의 MUX 채널별 디지털전압을 커패시턴스로 변환하는 변환함수를 최소 자승법을 이용하여 유도하였다. 개발된 시제품의 성능시험결과로 1회 측정시간이 4초 이내로 측정되었고, 192개 채널들의 반복적인 측정에서 최대값, 최소값, 평균값에 대한 측정 오차값이 5% 이내의 시험결과가 제시되었다.

Keywords

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