Nonparametric Identification of Wiener Systems Containing Backlash Type Operators

Model frequency identification is addressed for nonparametric Wiener systems containing backlash type nonlinearities. Interestingly, the borders of the backlash operator are allowed to be nonparametric. A frequency identification method is developed that determines the linear subsystem frequency response (at a number of frequencies) and the characteristic of the backlash operator (within a given working interval). The method involves the analysis of the form, spread and orientation closed loci characterizing the system frequency behaviour. All involved estimators are proved to be consistent.