PC-Camera based Monitoring for Unattended NC Machining

무인가공을 위한 PC 카메라 기반의 모니터링

  • Song, Shi-Yong (System Engineering Group, Production Engineering Research Institute, LG Electronics Inc) ;
  • Ko, Key-Hoon (Technical Research Center, VMS Solutions Co. Ltd) ;
  • Choi, Byoung-Kyu (Department of Industrial Engineering, KAIST)
  • 송시용 (LG전자생산기술원시스템기술그룹) ;
  • 고기훈 ((주)브이엠에스솔루션스기술연구소) ;
  • 최병규 (KAIST 산업공학과)
  • Received : 20051000
  • Accepted : 20060100
  • Published : 2006.03.31

Abstract

In order to make best use of NC machine tools with minimal labor costs, they need to be in operation 24 hours a day without being attended by human operators except for setup and tool changes. Thus, unattended machining is becoming a dream of every modern machine shop. However, without a proper mechanism for real-time monitoring of the machining processes, unattended machine could lead to a disaster. Investigated in this paper are ways to using PC camera as a real-time monitoring system for unattended NC milling operations. This study defined five machining states READY, NORMAL MACHINING, ABNORMAL MACHINING, COLLISION and END-OF-MACHINING and modeled them with DEVS (discrete event system) formalism. An image change detection algorithm has been developed to detect the table movements and a flame and smoke detection algorithm to detect unstable cutting process. Spindle on/off and cutting status could be successfully detected from the sound signals. Initial experimentation shows that the PC camera could be used as a reliable monitoring system for unattended NC machining.

Keywords

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