High-gain adaptive λ-tracking for nonlinear systems

Abstract

It is shown that a simple modification (introducing a dead zone in the adaptation law) of the known adaptive high-gain control strategy u( t) = - k( t) y( t), k( t) = ∥ y( t)∥ 2 yields λ-tracking in the presence of output corrupted noise for a large class of reference signals and a large class of multivariable nonlinear ‘minimum-phase’ systems of relative degree one. These results are applied to a realistic chemical reactor, showing the practical usefulness of these control laws.