On the stabilization and observation of nonlinear/uncertain dynamic systems

The problem of stabilization and observation of uncertain and/or nonlinear dynamic systems for which matching conditions are not satisfied is investigated. No statistical description of uncertain elements is assumed. The uncertain and/or nonlinear quantities are described only in terms of bounds on their possible sizes. Stabilizing feedback controllers and observers are proposed whose design is based on the constructive use of Lyapunov functions and the Bellman-Gronwall lemma.