Documents disponibles écrits par cet auteur

Parameter reduction in estimated model sets for robust control / Ryozo Nagamune in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 2 (Mars/Avril 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 2 (Mars/Avril 2010) . - 10 p. Titre : Parameter reduction in estimated model sets for robust control Type de document : texte imprimé Auteurs : Ryozo Nagamune, Auteur ; Jongeun Choi, Auteur Année de publication : 2010 Article en page(s) : 10 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Control  system  synthesis  Frequency  response  Least  squares  approximations  Principal  component  analysis  Robust  control  Uncertain  systems Index. décimale : 629.8 Résumé : This paper proposes two techniques for reducing the number of uncertain parameters in order to simplify robust controller design and to reduce conservatism inherent in robust controllers. The system is assumed to have a known structure with parametric uncertainties that represent plant dynamics variation. An original set of parameters is estimated by nonlinear least-squares (NLS) optimization using noisy frequency response functions. Utilizing the property of asymptotic normality for NLS estimates, the original parameter set can be reparameterized by an affine function of the smaller number of uncorrelated parameters. The correlation among uncertain parameters is detected by the principal component analysis in one technique and optimization with a bilinear matrix inequality in the other. Numerical examples illustrate the usefulness of the proposed techniques. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...] [article] Parameter reduction in estimated model sets for robust control [texte imprimé] / Ryozo Nagamune, Auteur ; Jongeun Choi, Auteur . - 2010 . - 10 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 2 (Mars/Avril 2010) . - 10 p. Mots-clés : Control  system  synthesis  Frequency  response  Least  squares  approximations  Principal  component  analysis  Robust  control  Uncertain  systems Index. décimale : 629.8 Résumé : This paper proposes two techniques for reducing the number of uncertain parameters in order to simplify robust controller design and to reduce conservatism inherent in robust controllers. The system is assumed to have a known structure with parametric uncertainties that represent plant dynamics variation. An original set of parameters is estimated by nonlinear least-squares (NLS) optimization using noisy frequency response functions. Utilizing the property of asymptotic normality for NLS estimates, the original parameter set can be reparameterized by an affine function of the smaller number of uncorrelated parameters. The correlation among uncertain parameters is detected by the principal component analysis in one technique and optimization with a bilinear matrix inequality in the other. Numerical examples illustrate the usefulness of the proposed techniques. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...]

Robust control synthesis techniques for multirate and multisensing track-following servo systems in hard disk drives / Ryozo Nagamune in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 132 N° 2 (Mars/Avril 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 2 (Mars/Avril 2010) . - 10 p. Titre : Robust control synthesis techniques for multirate and multisensing track-following servo systems in hard disk drives Type de document : texte imprimé Auteurs : Ryozo Nagamune, Auteur ; Xinghui Huang, Auteur ; Roberto Horowitz, Auteur Année de publication : 2010 Article en page(s) : 10 p. Note générale : Systèmes dynamiques Langues : Anglais (eng) Mots-clés : Control  system  synthesis  Disc  drives  Hard  discs  Linear  matrix  inequalities  Robust  control  Servomechanisms Index. décimale : 629.8 Résumé : This paper proposes controller design methods, specially for track-following control of the magnetic read/write head in a hard disk drive (HDD). The servo system to be considered is a general dual-stage multisensing system, which encompasses most of the track-following configurations encountered in the HDD industry, including the traditional single-stage system. For the general system, a robust track-following problem is formulated as a time-varying version of the robust H2 synthesis problem. Both dynamic and real parametric uncertainties, which are typical model uncertainties in track-following control, are taken into account in the formulation. Three optimal robust controller design techniques with different robustness guarantees are applied to solve the synthesis problem. These are mixed H2/H[infinity], mixed H2/µ, and robust H2 syntheses. Advantages and disadvantages of each method are presented. Multirate control, which is inherent to control problems in HDDs, is obtained by reducing multirate problems into linear time-invariant ones, for which there are many useful theories and algorithms available. Most of the techniques proposed in this paper heavily rely on efficient numerical tools for solving linear matrix inequalities. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...] [article] Robust control synthesis techniques for multirate and multisensing track-following servo systems in hard disk drives [texte imprimé] / Ryozo Nagamune, Auteur ; Xinghui Huang, Auteur ; Roberto Horowitz, Auteur . - 2010 . - 10 p. Systèmes dynamiques Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 132 N° 2 (Mars/Avril 2010) . - 10 p. Mots-clés : Control  system  synthesis  Disc  drives  Hard  discs  Linear  matrix  inequalities  Robust  control  Servomechanisms Index. décimale : 629.8 Résumé : This paper proposes controller design methods, specially for track-following control of the magnetic read/write head in a hard disk drive (HDD). The servo system to be considered is a general dual-stage multisensing system, which encompasses most of the track-following configurations encountered in the HDD industry, including the traditional single-stage system. For the general system, a robust track-following problem is formulated as a time-varying version of the robust H2 synthesis problem. Both dynamic and real parametric uncertainties, which are typical model uncertainties in track-following control, are taken into account in the formulation. Three optimal robust controller design techniques with different robustness guarantees are applied to solve the synthesis problem. These are mixed H2/H[infinity], mixed H2/µ, and robust H2 syntheses. Advantages and disadvantages of each method are presented. Multirate control, which is inherent to control problems in HDDs, is obtained by reducing multirate problems into linear time-invariant ones, for which there are many useful theories and algorithms available. Most of the techniques proposed in this paper heavily rely on efficient numerical tools for solving linear matrix inequalities. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://asmedl.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA00013200 [...]