Time-delay feedback control of lathe cutting tools

Abstract

For some machining operations, tool vibrations decay with time, the trivial solution is a stable equilibrium solution, and hence the machined surface is smooth. For other operating conditions, the trivial solution is unstable and the tool undergoes large oscillations called chatter, which might be periodic, quasiperiodic, or chaotic, and hence the surface finish will not be smooth. Therefore, chatter must be avoided or mitigated to maintain machining tolerances, preserve surface finish, and prevent tool breakage. Therefore, extensive research has been devoted to the understanding of the mechanisms of, modeling of, and methods of controlling machine–tool chatter. In this paper, we show that the region of linearly stable trivial solution can be widened considerably using time-delay acceleration feedback.