Tuning vibration absorbers to mitigate simultaneous regenerative and mode-coupling chatter

Abstract

This paper examines a set of parametric tunings for vibration absorbers to enhance stability in the event of simultaneous chatter during machining and proposes a novel tuning criterion of minimizing the definite integral of frequency response function, while accounting for damping of the absorber’s base component. Chatter vibrations are an inherent characteristic of machining processes, and a common tool for mitigating chatter is a tuned mass damper (TMD), which functions effectively when its dynamic characteristics are appropriately tuned to the natural frequency of the vibrating base component. Robotic machining is a recent cost-effective method of material removal, but simultaneous regenerative and mode-coupling chatter can arise on robot tools. TMD tuning criteria for mode-coupling and regenerative chatter are different, and tuning to suppress one may prompt the other. Moreover, conventional analytical tunings do not consider damping of the base component, which may be a valid assumption for low-damped machine tools but not for highly-damped robot tools. The possibility of simultaneous chatter and base component damping effect necessitates the exploration of alternative tuning criteria.