A novel control system for chatter suppression in turning

Abstract

The increasing requirements concerning machining precision and efficiency call for the development of machining system new control strategies, which should enable the process performance maximization. By assuming the productivity as main performance criterion, in this paper a novel control system based on a dedicated strategy for machining process control is presented at conceptual level. The process control strategy lays on a permanent assessment of the process current dynamical state, by referring the system operating point position to the stability limit, and on a periodic (but frequent) cutting regime adjustment in order to keep this point in the stability domain, as close as possible to the stability limit. The system operating point position is assessed by cutting-force on-line monitoring, followed by a dedicated feature extraction and reference to an interval of values characterizing the stability limit proximity domain. The system control algorithm has a sequential character, and consists in step by step increasing / decreasing the cutting speed or the feed rate, depending on the feature value position respect the target interval.