On the Robustness of Feedback Linearization of Lur'e Systems

Systems composed by a linear dynamical part feedback interconnected with a static nonlinearity are traditionally controlled by canceling the nonlinearity through a first feedback loop, and then designing a linear controller for the remaining linear dynamics. However, this procedure may provide unsatisfactory performance, and even lead to instability, in presence of uncertainty. In this paper we investigate the interplay between the robustness of the linear controller and the quality of the approximation of the nonlinearity, providing sufficient conditions for closed loop stability.