Nonparametric Identification of Nonlinear Systems in Series

In this paper, a method allowing the identification of two nonlinear systems in series is presented. More precisely, the identification of the second nonlinear subsystem under test is achieved by considering the effects of the nonlinearities of the first subsystem. The method is based on the estimation of the higher harmonic frequency responses from the measurement of distorted input and output signals. The second nonlinear system is then modeled by nonparametric generalized Hammerstein model made up of power series associated with linear filters. The method is experimentally validated in the well-known framework of nonlinear propagation of acoustic waves.