Frequency-domain subspace ıdentification of linear time periodic (LTP) systems
Date
2019Source Title
IEEE Transactions on Automatic Control
Print ISSN
0018-9286
Publisher
Institute of Electrical and Electronics Engineers
Volume
64
Issue
6
Pages
2529 - 2536
Language
English
Type
ArticleItem Usage Stats
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Abstract
This note proposes a new methodology for subspace-based state-space identification for linear time-periodic (LTP) systems. Since LTP systems can be lifted to equivalent linear time-invariant (LTI) systems, we first lift input-output data from the unknown LTP system as if it was collected from an equivalent LTI system. Then, we use frequency-domain subspace identification methods to find an LTI system estimate. Subsequently, we propose a novel method to obtain a time-periodic realization for the estimated lifted LTI system by exploiting the specific parametric structure of Fourier series coefficients of the frequency-domain lifting method. Our method can be used to both obtain state-space estimates for unknown LTP systems as well as to obtain Floquet transforms for known LTP systems. IEEE