IDENTIFICATION OF A NON-LINEAR SYSTEM USING WAVELET TRANSFORMATION
Wei-Jian Yi · Zhendong yu chongji · 2007
The wavelet transformation is used as a time-frequency representation for system identification. The impulse response of a Duffing system is transformed by using Morlet wavelet function and its transient frequencies and amplitudes are obtained from the ridge curves of its wavelet transformation. Its natural frequency, damping coefficient and nonlinear parameter are identified using curvefitting. Numerical simulation shows the correctness of the method proposed. It is also shown that the identification accuracy for the nonlinear parameter depends on the degree of nonlinearity and the initial amplitude.