• 제목/요약/키워드: Drill breakage monitoring

검색결과 3건 처리시간 0.021초

주축 및 Z축 모터전류를 이용한 드릴파손 예측에 관한 연구 (Study on Prediction of Drill Breakage using Spindle and Z-axis Motor Currents)

  • 김화영;안중환
    • 한국정밀공학회지
    • /
    • 제16권7호
    • /
    • pp.101-108
    • /
    • 1999
  • A reliable and practical monitoring of drill breakage is a crucial technique in automatic machining system. In this study, a real-time monitoring system was developed to predict drill breakage using both spindle and z-axis motor current. Drill breakage is monitored by detecting the level of residual motor current which is obtained through the moving average filter algorithm. The residual exhibits a feature of sharp decrease just before drill breakage. Therefore, drill breakage can be predicted by detecting this characteristic of residual component. Z-axis motor current is better to predict the drill breakage than spindle motor current, because the former is faster in response than the latter when drill breakage is occurred. The evaluation experiments have shown that the developed monitoring system works very well.

  • PDF

모터전류를 이용한 드릴가공에서의 절삭이상상태 감시 시스템 (Monitoring System for Abnormal Cutting States in the Drilling Operation using Motor Current)

  • 김화영;안중환
    • 한국정밀공학회지
    • /
    • 제12권5호
    • /
    • pp.98-107
    • /
    • 1995
  • The in-process detection of drill wear and breakage is one of the most importnat technical problems in unmaned machining system. In this paper, the monitoring system is developed to monitor abnormal drilling states such as drill breakage, drill wear and unstable cutting using motor current. Drill breakage is detected by level monitoring. Tool wear is classified by fuzzy pattern recognition. The key feature for classification of tool wear is the estimated flank wear which is calculated by the proposed flank wear model. The characteristic of the model is not sensitive to the variation of cutting conditions but is sensitive to drill wear state. Unstable cutting states due to the unsmooth chip disposal and the overload are monitored by the variance/mean ratio of spindle motor current. Variance/mean ratio also includes the information about the prediction of drill wear and drill breakage. The evaluation experiments have shown that the developed system works very well.

  • PDF

공작기계 지능화를 위한 다중 감시 시스템의 개발-드릴가공에의 적용- (Development of a Multiple Monitioring System for Intelligence of a Machine Tool -Application to Drilling Process-)

  • 김화영;안중환
    • 한국정밀공학회지
    • /
    • 제10권4호
    • /
    • pp.142-151
    • /
    • 1993
  • An intelligent mulitiple monitoring system to monitor tool/machining states synthetically was proposed and developed. It consists of 2 fundamental subsystems : the multiple sensor detection unit and the intellignet integrated diagnosis unit. Three signals, that is, spindle motor current, Z-axis motor current, and machining sound were adopted to detect tool/machining states more reliably. Based on the multiple sensor information, the diagnosis unit judges either tool breakage or degree of tool wear state using fuzzy reasoning. Tool breakage is diagnosed by the level of spindle/z-axis motor current. Tool wear is diagnosed by both the result of fuzzy pattern recognition for motor currents and the result of pattern matching for machining sound. Fuzzy c-means algorithm was used for fuzzy pattern recognition. Experiments carried out for drill operation in the machining center have shown that the developed system monitors abnormal drill/states drilling very reliably.

  • PDF