Table of Contents Author Guidelines Submit a Manuscript
Mathematical Problems in Engineering
Volume 2013, Article ID 192431, 7 pages
Research Article

Robust Output Feedback Stabilization of a Field-Sensed Magnetic Suspension System

1Department of Electrical Engineering, Kun Shan University, Tainan City, Taiwan
2Department of Electrical Engineering, Southern Taiwan University of Science and Technology, Tainan City 710, Taiwan

Received 4 February 2013; Revised 6 May 2013; Accepted 7 May 2013

Academic Editor: Cheng Shao

Copyright © 2013 Jen-Hsing Li and Juing-Shian Chiou. 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.


The magnetic suspension system (MSS) is very important in many engineering applications. This paper proposes the dynamic output feedback control of a field-sensed MSS (FSMSS). Subsequently, the mathematical model of the MSS is described by discrete-time systems. Ideally, the coefficients of a nominal polynomial can precisely determine the Schur stability. But in reality, the coefficients may contain uncertainties due to reasons such as computational errors. Therefore, there is a need to address the problem of robust stability for discrete-time systems. In this paper, the size of allowable perturbation in polynomial coefficient space was estimated for the output feedback control of the MSS. The -norm and a lower bound for the size of the Schur stability hypercube are provided in this paper.