Stability conditions for systems with parametric uncertainties and nonlinear feedback

The purpose of this paper is to use the passivity theorem to derive new stability conditions for a class of systems that consist of a linear subsystem with parametric uncertainty and nonlinear feedback. To address the inherent conservativism in applying the passivity theorem, causal multipliers are introduced into the analysis and it is shown that a Popov-like stability condition results. The stability results are then extended for noncausal multipliers using the notion of positivity.<
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