Mechatronic analysis of a complex transmission chain for performance optimization in a machine tool

Mechatronic models of complex mechanical systems allow to assemble reliable simulators, which can be used to test alternative choices made at component level. When the complexity of the system is significant, however, it is neither easy to model the interactions among different elements, nor immediate to identify the components responsible for a possible loss of performance of the system. Based on a detailed linear model of a complex transmission chain used within a large size machine tool, this paper contributes presenting a methodology, supported by modal analysis, to quantify the sensitivity of each vibration mode to the stiffness of each component. A nonlinear simulator of the transmission has been derived, too, and its remarkable performance in reproducing the experiments is demonstrated. Insight on the role of Coulomb friction is also provided, together with a practical way to split the overall friction between motor and load sides.