211 Comparison of Analysis Methods for Nonlinear System Identification

Abstract

In this paper, we compare results of Short Time Fourier Transform, Wavelet Analysis, Time-Frequency Analysis based on Digital Filter and High Order Spectrum Analysis, and discuss on effectiveness and problems of these methods of analysis for non-linear system. The Time-Frequency Analysis, based on the well-known digital filter, is expected improvement of frequency resolution of transient phenomena. And High Order Spectrum Analysis is expected direct evaluation of non-linear vibration. First, we constitute three kinds of numerical model including nonlinear element and simulate vibration responses for exciting input that frequency characteristic changes. Then, we apply four kinds of analytical methods to those results and discuss on effectiveness and problems of these methods of analysis for non-linear system.