Biased norms and robustness analysis for nonlinear feedback systems

This paper outlines an extension of a framework, previously developed by the authors, for robustness analysis of nonlinear systems. Typical cases that this extension covers are: uncertain biases, and the presence of several equilibria for the autonomous system with the forced response not being confined to the vicinity of any one of them. Stability is considered from an input-output point of view with a suitable biased norm to quantify the effect of disturbances and errors.