AN IMPROVED POWER THRESHOLD METHOD FOR ESTIMATING TOOL WEAR DURING MILLING

摘要

It is well known that cutting forces increase as a cutting tool wears out. Current Tool Condition Monitoring (TCM) systems use this fact to set a threshold for the allowable percent power increase corresponding to a worn out tool. Typically, a training process is required whereby the first few parts cut with a sharp tool provide a baseline for comparison. We describe a TCM system that can estimate tool wear without the necessity of a training process. Our hypothesis is that tool wear can be accurately correlated with the coefficients of a tangential cutting force model. The model coefficients are estimated by online measurement of spindle motor power.