Computer-assisted Prediction of Drill-failure Using In-process Measurements of Thrust Force

Abstract

A real time control system has been developed in the laboratory to monitor the performance of twist drills. Emphasis has been placed on the prediction of the incipient failure of the drill and retraction before significant damage has occurred. It has been found that the gradient of the drilling thrust force, calculated using a digital filter with the necessary frequency specifications, exhibits a sharp increase several seconds before any serious failure. Details of the filtering technique and results for several cutting conditions are presented.