Lavaei, Javad and Aghdam, Amir G.
(2008)
*Control of continuous-time LTI systems by means of structurally constrained controllers.*
Automatica, 44
(1).
pp. 141-148.
ISSN 00051098

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Official URL: http://dx.doi.org/10.1016/j.automatica.2007.04.027

## Abstract

This paper deals with the characterization of the fixed modes of multi-channel systems with respect to linear time-invariant (LTI) structurally constrained controllers. Fixed modes can be found numerically for any LTI system with respect to any given control structure, using a random number generator. The existing analytical methods, however, are not capable of characterizing the fixed modes in the most general case of non-strictly proper systems with non-block diagonal (i.e., overlapping) control structure, efficiently. The notion of a decentralized overlapping fixed mode (DOFM) is introduced in this paper to address the above problem in the most general case. To this end, the knowledge of the overlapping control structure is translated into a bipartite graph, whose vertices correspond to the input and output vectors of various control channels. An efficient technique is applied to the obtained graph to identify the DOFMs of the system. It is to be noted that a system is stabilizable via an appropriate LTI decentralized overlapping controller if and only if it does not have any unstable DOFM. Moreover, it is shown how those modes which are not DOFMs can be placed freely in the complex plane using a proper LTI decentralized overlapping controller. The efficacy of this work is demonstrated through an example.

Divisions: | Concordia University > Gina Cody School of Engineering and Computer Science > Electrical and Computer Engineering |
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Item Type: | Article |

Refereed: | Yes |

Authors: | Lavaei, Javad and Aghdam, Amir G. |

Journal or Publication: | Automatica |

Date: | 2008 |

Digital Object Identifier (DOI): | 10.1016/j.automatica.2007.04.027 |

Keywords: | Decentralized control; Overlapping systems; Stabilizability; Graph theory |

ID Code: | 975166 |

Deposited By: | Danielle Dennie |

Deposited On: | 22 Jan 2013 13:55 |

Last Modified: | 18 Jan 2018 17:39 |

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