Uncertainty observer-based robust tracking control for high-order nonlinear systems using forwarding technique. Issue 12 (2nd December 2017)

• Record Type: Journal Article
• Authors: Zhang, X.; Huang, X.L.; Lu, H.Q.
• Is Part Of: International journal of control. Volume 90:Issue 12(2017)
• Page Start: 2641
• Page End: 2654
• Publication Date: 2017-12-02
• Subjects: High-order nonlinear systems -- robust tracking control -- forwarding technique -- uncertainty observer -- complexity of explosion; Automatic control -- Periodicals; Electronic journals; 629.8
• DOI: 10.1080/00207179.2016.1262968
• Languages: English
• ISSNs: 0020-7179

Abstract

ABSTRACT: Based on uncertainty observers, we develop a robust tracking control approach for high-order nonlinear systems subject to uncertainties satisfying mismatched condition. In this study, by combining with forwarding technique, uncertainty observers are designed to estimate uncertainties including parameter perturbations and external disturbances in a bottom-up way; at the same time, the convergence rate of estimate error of uncertainty observers is analysed in detail. The insensitivity to uncertainties for each manifold, no need of a prior knowledge on the bound of the uncertainty and the feasibility of practical implementation are three advantages of the proposed scheme. Moreover, approximate error of uncertainty observer can be made sufficiently small by tuning the parameters. The design procedures are elaborated and the boundedness of all trajectories of the closed-loop systems is guaranteed. Two examples are illustrated, highlighting the superiority of the proposed methodology via comparison with other control strategies.