Patent ID: 6507798
Filing Date: 2003-01-14
Classification: G06F

Abstract:
A method for empirical analysis of damping behavior of a physical system comprising the steps of: receiving time series data representing behavior of said system; performing empirical mode decomposition on said time series data to calculate intrinsic mode functions ck(t) for a set of modes (k); creating complex function time series, ck(t)+idk(t), for said intrinsic mode functions by means of Hilbert transforms dk(t); defining from polar forms of said complex function time series, time-dependent amplitude functions ak(t) and time-dependent frequency functions &ohgr;k(t); calculating a damping loss factor &eegr;k(t) for each of said modes from the time dependent amplitude and frequency functions; mapping the damping loss factor for each of said modes into a time frequency domain; calculating a full damping spectrum of the damping loss factors as function of frequency and time from said mapping to evaluate said damping behavior of the physical system; selecting a frequency band; and utilizing root mean square average of the mapped damping loss factors over the frequencies of the selected band to replace the frequency and time functions of the mapped damping loss factors for formulation thereof exclusively as a time-dependent function based on the frequency band B=(&ohgr;1,&ohgr;2).