Robustification tool for adaptive non-linear control

This paper presents a conceptually simple robustification approach for the adaptive control of a class of non-linear systems with static and dynamic uncertainties. This approach generates a new class of robust adaptive non-linear controllers and is based upon a combined application of the well-known adaptive backstepping and recent non-linear small-gain techniques. The presented method is illustrated via a third-order chemical reactor with only temperature information, and under relaxed conditions. An adaptive output-feedback stabilizer is obtained without resorting to any state observer.