Computation of stability diagrams for milling processes with parallel kinematic machine tools

Abstract

A characteristic property of parallel kinematic structures is the strong pose dependency of their dynamic behaviour. For machine tools based on a parallel kinematic concept, the pose dependency of the dynamic behaviour can influence the dynamic stability of cutting processes such as turning or milling. In this contribution, modelling techniques are presented which allow for an efficient computation of pose-dependent stability diagrams. In a case study, it is shown that the H2-norm can serve as a valid criterion for model reduction, which is necessary for handling complex machine models in the context of dynamic stability analysis of cutting processes. The pose-dependent dynamic properties of the six-degrees-of-freedom hexapod machine tool Paralix are investigated, and pose-dependent stability diagrams for two example trajectories are presented.