Identification of a crystal detector using a block structured nonlinear feedback model

This paper studies the identification of a block structured nonlinear Wiener-Hammerstein system that is captured in the feed forward or the feedback path of a closed loop system. First nonparametric initial estimates are generated for the three dynamic blocks, modelled by their frequency response function, and the static nonlinear system, described using cubic splines. Next a parametric model is identified. Random or periodic excitations can be used in the experiments. The method is illustrated on the identification of an Agilent HP420C crystal detector.