Approximate Decoupling of Regularly Perturbed Nonlinear Systems

Conditions for static state feedback decoupling with internal stability may not hold for a regularly perturbed system even though they hold for the unperturbed system. We show for the case where the objective for the decoupled controller is asymptotic trackimg, that with small iterative corrections on the decoupling controller for the unperturbed system, we can achieve decoupled tracking within 0(E^k) error where k is the order of the iteration, even when the regular perturbation makes the system nonminimum phase.