• 한국기계가공학회지
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• 제15권6호
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• pp.64-69
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• 2016

Vehicle clutch measurement for disc cushion variation was developed for the production of high quality Dual clutch transmissions. The developed device is composed of load cells for load measurement and LVDT for measuring the distance variation measurement in cushion variation. The servo motor-driven electric press for flexible loads that was developed was controlled by a PC-based HMI system, LabVIEW, and the device was able to continuously record real time measurement data with the accuracies of ${\pm}0.1\;kgf$ load and ${\pm}5{\mu}m$ cushion amount, which is far above the requirements of commercial vehicle standards.

• 한국전자통신학회논문지
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• 제9권2호
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• pp.161-166
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• 2014

습기와 먼지가 많은 장소에서도 내환경성을 가지면서 고감도로 미세 금속편 감지가 가능한 전자장 방식 선형가변차동변압기를 이용한 금속감지 방식에 대하여 연구하였다. 초장파에서 장파에 걸친 3개 주파수 대역에서 위상검파 방식을 사용하여 각 주파수별 금속감지 특성을 실험적으로 측정하였다. 주파수가 증가하면 금속감지 및 금속편이 포함되는 동물성 식품에 대한 감도는 기하급수적으로 증가함을 알 수 있었다. 또한 위상검파 후단의 저역통과필터의 대역폭을 축소하여 감도를 비례하여 증가시킬 수 있었고, 대역통과필터 대역폭과 신호대잡음비를 최적화하여 철 시편에 대한 감지 감도를 향상시킬 수 있었다. 시험용 철 시편을 사용한 감지 감도 한계는 동물성 식품에 대한 변별력이 좋은 50kHz 초장파 대역에서 최저 지름 0.7mm의 철 시편까지 금속감지가 가능함을 보여주었다.

• 한국기계가공학회지
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• 제14권4호
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• pp.151-159
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• 2015

In this study, we developed an automated contact-type thickness measurement machine that continuously and precisely measures the thickness of a PCB module product using multi-LVDT sensors. The system contains a measurement part to automatically measure the thickness in real time according to the set conditions with an alignment supply unit and unloading unit to separate OK and NG products. The sensors were calibrated before assembly in the measuring machine, and precision and accuracy performance tests were also performed to reduce uncertainty errors in the measurement machine. In the calibration test, the precision errors of the LVDT sensor were determined to be $1-3{\mu}m$ as 0.1% at the measuring range. A measurement error of 0.8 mm and 1.0 mm thickness test standards were found to be $1{\mu}m$ and $4{\mu}m$, and the standard deviations of two 1.0 mm products were measured as $14{\mu}m$ and $8{\mu}m$, respectively. In the measurement system analysis, the accuracies of test PCB standards were found to be $2{\mu}m$ and $3{\mu}m$, respectively. From the results of gage repeatability and reproducibility (R & R) crossed, we found that the machine is suitable for the measurement and process control in the mass production line as 7.92% of total gage R & R and in seven distinct categories. The maximum operating speed was limited at 13 pcs/min, showing a value good enough to measure.