Active chatter supression in an octahedral hexapod milling machine: a design study

This paper describes a design study to determine the feasibility of integrating active control into a milling machine to enhance milling-process performance. The study described herein focuses on the active suppression of chatter instabilities in an Octahedral Hexapod Milling (OHM) machine. Structural dynamics contributing to chatter instabilities were described using calibrated finite element models, which were coupled with a tool-workpiece interaction model for purposes of determining, by simulation, machine performance enhancement due to active control. An active vibration control design to minimize vibration at the tool tip was also integrated into the simulation. Active control subcomponent and actuator size requirements were determined from the modeling and simulations. The study showed that active control is a feasible solution for suppressing chatter instabilities, allowing the metal removal rate of the OHM machine to be increased by roughly a factor of two.