Exact compensation of unmatched perturbation via quasi-continuous HOSM

Abstract

This paper studies nonlinear systems control when unmatched perturbations are present. A new control scheme, based on block control and quasi-continuous HOSM techniques, is proposed. The proposed method assures exact finite time tracking, for the desired signal, regardless of unmatched perturbations. The proposed control design is tested through a simulation example.

Integral HOSM Semiglobal Controller for Finite-Time Exact Compensation of Unmatched Perturbations

“…The results 0018-9286/$26.00 © 2010 IEEE achieved in [2] are local and, for the sake of completeness, described in next section.…”

“…In the first part of this section the Quasi-continuous controller is briefly introduced, after that the design algorithm reported in [2] is restated for reader convenience and in the third part the integral HOSM approach is introduced.…”

“…In [2], HOSM and feedback compensation is introduced through several virtual controls in order to ensure the desired tracking. The results 0018-9286/$26.00 © 2010 IEEE achieved in [2] are local and, for the sake of completeness, described in next section.…”

“…In Section II the class of nonlinear systems to be treated and the problem formulation are described. Section III introduces the Quasi-continuous control [4], the hierarchical design algorithm proposed in [2] and finally introduces the integral HOSM [3]. Section IV presents the modification to the hierarchical design algorithm and its convergence proof.…”

“…In [2] a new design algorithm for systems in strict-feedback form, a special case of the BC-form, is proposed. This algorithm achieves finite-time exact tracking of the desired output in the presence of smooth unmatched perturbations.…”