Extending the Root-Locus Method to Fractional-Order Systems

The well-known root-locus method is developed for special subset of linear time-invariant systems known as fractional-order systems. Transfer functions of these systems are rational functions with polynomials of rational powers of the Laplace variable s. Such systems are defined on a Riemann surface...

Full description

Saved in:
Bibliographic Details
Main Authors: Farshad Merrikh-Bayat, Mahdi Afshar
Format: Article
Language:English
Published: Wiley 2008-01-01
Series:Journal of Applied Mathematics
Online Access:http://dx.doi.org/10.1155/2008/528934
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832561250620407808
author Farshad Merrikh-Bayat
Mahdi Afshar
author_facet Farshad Merrikh-Bayat
Mahdi Afshar
author_sort Farshad Merrikh-Bayat
collection DOAJ
description The well-known root-locus method is developed for special subset of linear time-invariant systems known as fractional-order systems. Transfer functions of these systems are rational functions with polynomials of rational powers of the Laplace variable s. Such systems are defined on a Riemann surface because of their multivalued nature. A set of rules for plotting the root loci on the first Riemann sheet is presented. The important features of the classical root-locus method such as asymptotes, roots condition on the real axis, and breakaway points are extended to fractional case. It is also shown that the proposed method can assess the closed-loop stability of fractional-order systems in the presence of a varying gain in the loop. Three illustrative examples are presented to confirm the effectiveness of the proposed algorithm.
format Article
id doaj-art-d92c20f470e14fcbb73ed4d47c3e4837
institution Kabale University
issn 1110-757X
1687-0042
language English
publishDate 2008-01-01
publisher Wiley
record_format Article
series Journal of Applied Mathematics
spelling doaj-art-d92c20f470e14fcbb73ed4d47c3e48372025-02-03T01:25:35ZengWileyJournal of Applied Mathematics1110-757X1687-00422008-01-01200810.1155/2008/528934528934Extending the Root-Locus Method to Fractional-Order SystemsFarshad Merrikh-Bayat0Mahdi Afshar1Department of Electrical Engineering, Zanjan University, Zanjan, IranDepartment of Mathematics, Zanjan Azad University, Zanjan, IranThe well-known root-locus method is developed for special subset of linear time-invariant systems known as fractional-order systems. Transfer functions of these systems are rational functions with polynomials of rational powers of the Laplace variable s. Such systems are defined on a Riemann surface because of their multivalued nature. A set of rules for plotting the root loci on the first Riemann sheet is presented. The important features of the classical root-locus method such as asymptotes, roots condition on the real axis, and breakaway points are extended to fractional case. It is also shown that the proposed method can assess the closed-loop stability of fractional-order systems in the presence of a varying gain in the loop. Three illustrative examples are presented to confirm the effectiveness of the proposed algorithm.http://dx.doi.org/10.1155/2008/528934
spellingShingle Farshad Merrikh-Bayat
Mahdi Afshar
Extending the Root-Locus Method to Fractional-Order Systems
Journal of Applied Mathematics
title Extending the Root-Locus Method to Fractional-Order Systems
title_full Extending the Root-Locus Method to Fractional-Order Systems
title_fullStr Extending the Root-Locus Method to Fractional-Order Systems
title_full_unstemmed Extending the Root-Locus Method to Fractional-Order Systems
title_short Extending the Root-Locus Method to Fractional-Order Systems
title_sort extending the root locus method to fractional order systems
url http://dx.doi.org/10.1155/2008/528934
work_keys_str_mv AT farshadmerrikhbayat extendingtherootlocusmethodtofractionalordersystems
AT mahdiafshar extendingtherootlocusmethodtofractionalordersystems