“…Although, experimental results are very often compared with FEM results [3,17], the problem of experimental signal analysis remains an open question. Different methods of signal analysis are applied in order to recognize chatter vibrations in cutting operations, including multifractal and wavelet approaches [38], multiscale entropy [23] HilbertHuang transform [20], recurrence analysis [22], flicker-noise spectroscopy [21] and audio signal analysis [32]. As it was mentioned before, the HSM method is also applied to thin-walled aluminium components for the aircraft industry to increase productivity [8].…”