Table of Contents
Advances in Numerical Analysis
Volume 2011, Article ID 184314, 15 pages
Research Article

Refinement Methods for State Estimation via Sylvester-Observer Equation

Department of Applied Mathematics, Faculty of Mathematical Sciences, University of Guilan, P.O. Box 1914, Rasht, Iran

Received 6 December 2010; Revised 26 April 2011; Accepted 14 June 2011

Academic Editor: William J. Layton

Copyright © 2011 H. Saberi Najafi and A. H. Refahi Sheikhani. 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.


We present new iterative methods based on refinement process for solving large sparse Sylvester-observer equations applied in state estimation of a continuous-time system. These methods use projection methods to produce low-dimensional Sylvester-observer matrix equations that are solved by the direct methods. Moreover, the refinement process described in this paper has the capability of improving the results obtained by any other methods. Some numerical results will be reported to illustrate the efficiency of the proposed methods.