ANALYSIS OF NONLINEAR SYSTEM USING NARMA MODELS

The purpose of this paper is to develop a systematic method of time-domain nonlinear system identification using NARMA model. In the beginning the Hilbert transform test was used for nonlinearity, then an orthogonal parameter estimation algorithm is applied to a NARMA model which represents the nonlinear system model. Finally the nonlinear frequency response functions were computed. Application of the methodology to a combined Duffing and Van Der Pol nonlinear system and the seismic response data of Van Nuys building to Whittier and Northridge earthquakes are studied.