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Mathematical Problems in Engineering
Volume 2012 (2012), Article ID 451843, 22 pages
http://dx.doi.org/10.1155/2012/451843
Research Article

Fault Reconstruction Based on Sliding Mode Observer for Nonlinear Systems

College of Electrical and Information Engineering, Hunan University of Technology, Hunan, Zhuzhou 412007, China

Received 22 August 2012; Accepted 31 October 2012

Academic Editor: Huaguang Zhang

Copyright © 2012 Jing He and Changfan Zhang. 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

This paper presents a precision fault reconstruction scheme for a class of nonlinear systems involving unknown input disturbances. First, using the coordinate transformation algorithm, the disturbances and faults of the system are fully decoupled. Therefore, it is possible to eliminate the influence of disturbances to the system, namely, better disturbances robustness. On this basis, the design of a sliding mode state observer makes the most genuine reconstruction realizable, instead of estimation of faults. Furthermore, with the equivalent principle of sliding mode variable structure, the precision reconstruction of arbitrary nonlinear faults is achieved. Finally, the applications of fault reconstruction in a third-order nonlinear theoretical model with disturbances and in a single-link robot system, respectively, have demonstrated the validity of the proposed scheme.