On well‐definability of the L∞/L2 Hankel operator and detection of all the critical instants in sampled‐data systems

Abstract Because sampled‐data systems have h‐periodic nature with the sampling period h, an arbitrary Θ∈[0,h) is taken and the quasi L∞/L2 Hankel operator at Θ is defined as the mapping from L2(−∞,Θ) to L∞[Θ,∞). Its norm called the quasi L∞/L2 Hankel norm at Θ is used to define the L∞/L2 Hankel norm...

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Main Authors: Tomomichi Hagiwara, Akira Inai, Jung Hoon Kim
Format: Article
Language:English
Published: Wiley 2021-03-01
Series:IET Control Theory & Applications
Subjects:
Online Access:https://doi.org/10.1049/cth2.12069
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author Tomomichi Hagiwara
Akira Inai
Jung Hoon Kim
author_facet Tomomichi Hagiwara
Akira Inai
Jung Hoon Kim
author_sort Tomomichi Hagiwara
collection DOAJ
description Abstract Because sampled‐data systems have h‐periodic nature with the sampling period h, an arbitrary Θ∈[0,h) is taken and the quasi L∞/L2 Hankel operator at Θ is defined as the mapping from L2(−∞,Θ) to L∞[Θ,∞). Its norm called the quasi L∞/L2 Hankel norm at Θ is used to define the L∞/L2 Hankel norm as the supremum of their values over Θ∈[0,h). If the supremum is actually attained as the maximum, then a maximum‐attaining Θ is called a critical instant and the L∞/L2 Hankel operator is said to be well‐definable. An earlier study establishes a computation method of the L∞/L2 Hankel norm, which is called a sophisticated method if our interest lies only in its computation. However, the feature of the method that it is free from considering the quasi L∞/L2 Hankel norm for any Θ∈[0,h) prevents the earlier study to give any arguments as to whether the obtained L∞/L2 Hankel norm is actually attained as the maximum, as well as detecting all the critical instants when the L∞/L2 Hankel operator is well‐definable. This paper establishes further arguments to tackle these relevant questions and provides numerical examples to validate the arguments in different aspects of authors' theoretical interests.
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spelling doaj.art-ff072f23d0d44c8186a3703a6ce739092022-12-22T02:05:52ZengWileyIET Control Theory & Applications1751-86441751-86522021-03-0115566868210.1049/cth2.12069On well‐definability of the L∞/L2 Hankel operator and detection of all the critical instants in sampled‐data systemsTomomichi Hagiwara0Akira Inai1Jung Hoon Kim2Department of Electrical Engineering Kyoto University Kyoto JapanDepartment of Electrical Engineering Kyoto University Kyoto JapanDepartment of Electrical Engineering Pohang University of Science and Technology (POSTECH) Pohang Republic of KoreaAbstract Because sampled‐data systems have h‐periodic nature with the sampling period h, an arbitrary Θ∈[0,h) is taken and the quasi L∞/L2 Hankel operator at Θ is defined as the mapping from L2(−∞,Θ) to L∞[Θ,∞). Its norm called the quasi L∞/L2 Hankel norm at Θ is used to define the L∞/L2 Hankel norm as the supremum of their values over Θ∈[0,h). If the supremum is actually attained as the maximum, then a maximum‐attaining Θ is called a critical instant and the L∞/L2 Hankel operator is said to be well‐definable. An earlier study establishes a computation method of the L∞/L2 Hankel norm, which is called a sophisticated method if our interest lies only in its computation. However, the feature of the method that it is free from considering the quasi L∞/L2 Hankel norm for any Θ∈[0,h) prevents the earlier study to give any arguments as to whether the obtained L∞/L2 Hankel norm is actually attained as the maximum, as well as detecting all the critical instants when the L∞/L2 Hankel operator is well‐definable. This paper establishes further arguments to tackle these relevant questions and provides numerical examples to validate the arguments in different aspects of authors' theoretical interests.https://doi.org/10.1049/cth2.12069Combinatorial mathematicsDiscrete control systems
spellingShingle Tomomichi Hagiwara
Akira Inai
Jung Hoon Kim
On well‐definability of the L∞/L2 Hankel operator and detection of all the critical instants in sampled‐data systems
IET Control Theory & Applications
Combinatorial mathematics
Discrete control systems
title On well‐definability of the L∞/L2 Hankel operator and detection of all the critical instants in sampled‐data systems
title_full On well‐definability of the L∞/L2 Hankel operator and detection of all the critical instants in sampled‐data systems
title_fullStr On well‐definability of the L∞/L2 Hankel operator and detection of all the critical instants in sampled‐data systems
title_full_unstemmed On well‐definability of the L∞/L2 Hankel operator and detection of all the critical instants in sampled‐data systems
title_short On well‐definability of the L∞/L2 Hankel operator and detection of all the critical instants in sampled‐data systems
title_sort on well definability of the l∞ l2 hankel operator and detection of all the critical instants in sampled data systems
topic Combinatorial mathematics
Discrete control systems
url https://doi.org/10.1049/cth2.12069
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