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Discrete Dynamics in Nature and Society
Volume 2014 (2014), Article ID 619010, 10 pages
http://dx.doi.org/10.1155/2014/619010
Research Article

Output Tracking via Adaptive Backstepping Higher Order Integral Sliding Mode for Uncertain Nonlinear Systems

1Department of Electrical Engineering, COMSATS Institute of Information Technology (CIIT), Park Road, Chak Shahzad, Islamabad 44000, Pakistan
2Center for Advanced studies in Telecom, COMSATS (CIIT), Park Road, Chak Shahzad, Islamabad 44000, Pakistan
3Department of Electronics Engineering, MAJU, Express Highway, Kahuta Road, Islamabad 44000, Pakistan

Received 13 December 2013; Accepted 26 January 2014; Published 6 March 2014

Academic Editor: Jinde Cao

Copyright © 2014 M. Pervaiz et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The authors propose a new tracking control design strategy for uncertain non-linear systems which are convertible to Semi-Strict Feedback Form (SSFF). The system in SSFF is first converted into new variables via existing adaptive backstepping control techniques. The control law is obtained by combining adaptive backstepping procedure and higher order integral sliding mode. The component of control law designed via backstepping is continuous which shows robustness against parametric uncertainties where as the discontinuous control component provides robustness against unmodeled dynamics and external disturbances. Since, this strategy relies on an integral manifold of the adaptively developed variables, therefore, the reaching phase is eliminated in this approach, which is an advantage in term of robustness. Furthermore, the parameters update law correctly provides the estimation of parameters which is again results in enhanced robustness of the strategy. The stability of proposed method is analysed theoretically and validated through a numerical example.