Modelling and understanding of chatter

Abstract

Recent analysis in chatter modelling of BTA deep­hole drilling consisted in phenomenological modelisation of relationships between the ob­ served time series and appearance of chatter during the process. Using the newly developed MEWMA control chart [4, 5], it has even been possible to predict the occurence of chatter about 30 to 50 mm in advance (i.e. up to one minute before the chatter starts). Unfortunately, no relationships between the machine and model param­eters have been detected. Therefore, in this paper a physical model of the boring bar is taken into account. Simulation studies of the regenerative pro­cess are performed. These simulated time series show the same characteristics as the data recorded during the drilling process and thus support the validity of our model. By running such simulations, we intend to find strategies for chatter prevention in future work.