Global practical tracking control for a class of uncertain non-linear systems

This study addresses the problem of global practical tracking via output feedback for a class of uncertain non-linear systems. First, the authors design a homogeneous state observer and controller using the generalised adding power integrator technique in a recursive way for the nominal system without the perturbing non-linearities. Then based on the homogeneous domination approach, a scaling gain is introduced into the proposed output feedback stabiliser to achieve the small tracking error arbitrarily. The simulation results worked out in an example verify the theory. The proposed approach can also widen the applicability to a broader class of systems with non-triangular structure.