Explicit Form of Lyapunov Functions for a Class of Nonlinear Feedback Systems Augmented with Observers
The paper suggests conditions for presence of quadratic Lyapunov functions for nonlinear observer based feedback systems with an 'input nonlinearity' in the feedback path. Provided that the system using state feedback satisfies the Circle Criterion (i.e., when all states can be measured), we show that the extended system with only output feedback control from a (full state) Luenberger-type observe
