Identification of a wiener system with some general discontinuous nonlinearities

Abstract A nonlinear dynamic system can be described by a Wiener system which is a linear dynamic subsystem combined with a nonlinear static subsystem. And general discontinuous nonlinearities are very popular in a real system. This paper presents a new recursive identification method to a Wiener system with different general discontinuous nonlinearities. It is assumed that the linear subsystem model structure and the type of the discontinuous nonlinearities are known in prior. By using the key term separation principle and constructing intermediate variables, such a Wiener system can be approximately transformed into a pseudo-linear MISO system. Using the adaptive recursive pseudo-linear regressions (RPLR) for a linear MISO dynamic system and smoothing and filtering techniques to estimate the intermediate variables, satisfied parameter estimates of the nonlinear dynamic system can be obtained in the presence of a colored measurement noise without parameter redundancy. Simulation examples are also given to illustrate the correctness of the developed method.