Chatter control in the high-speed milling process using μ-synthesis

Chatter is an instability phenomenon in machining processes which limits productivity and results in inferior work-piece quality, noise and rapid tool wear. The increasing demand for productivity in the manufacturing community motivates the development of an active control strategy to shape the chatter stability boundary of manufacturing processes. In this work a control methodology for the high-speed milling process that alters the chatter stability boundary such that the number of chatter-free operating points is increased and a higher productivity can be attained. The methodology developed in this paper is based on a robust control approach using mu-synthesis. Hereto, the most important process parameters (depth of cut and spindle speed) are treated as uncertainties. Effectiveness of the methodology is demonstrated by means of illustrative examples.