Documents disponibles écrits par cet auteur

Designing nonlinear zero dynamics to reject periodic waveforms / Brad E. Paden in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 131 N° 4 (Juillet 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 4 (Juillet 2009) . - 04 p. Titre : Designing nonlinear zero dynamics to reject periodic waveforms Type de document : texte imprimé Auteurs : Brad E. Paden, Auteur ; Nasim Mirnateghi, Auteur ; Luca Gentili, Auteur Année de publication : 2009 Article en page(s) : 04 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : linear  systems;  designers  use  zeros;  disturbance;  nonlinear  zero  dynamics Résumé : In linear systems, designers use zeros for loop-shaping and the attenuation of disturbances. For example, imaginary-axis zeros can be used to reject sinusoids at a specific frequency such as a 50 Hz or 60 Hz power line interference. If the disturbance is nonsinusoidal, repetitive control methods may be used but additional controller states for each harmonic are required. Thus, rejecting periodic disturbance that are nonsinusoidal with low controller order remains an open problem. In this paper, we constructively design low-order nonlinear dynamics that reject a nonsinusoidal disturbance. We identify a particular case of the nonlinear regulator theory wherein the Byrnes–Isidori PDE has a simple solution. This case leads to a constructive procedure for designing nonlinear zero dynamics in systems with input disturbances. The constructive procedure is accessible to designers who do not have experience with the nonlinear geometric control theory. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26497&di [...] [article] Designing nonlinear zero dynamics to reject periodic waveforms [texte imprimé] / Brad E. Paden, Auteur ; Nasim Mirnateghi, Auteur ; Luca Gentili, Auteur . - 2009 . - 04 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 4 (Juillet 2009) . - 04 p. Mots-clés : linear  systems;  designers  use  zeros;  disturbance;  nonlinear  zero  dynamics Résumé : In linear systems, designers use zeros for loop-shaping and the attenuation of disturbances. For example, imaginary-axis zeros can be used to reject sinusoids at a specific frequency such as a 50 Hz or 60 Hz power line interference. If the disturbance is nonsinusoidal, repetitive control methods may be used but additional controller states for each harmonic are required. Thus, rejecting periodic disturbance that are nonsinusoidal with low controller order remains an open problem. In this paper, we constructively design low-order nonlinear dynamics that reject a nonsinusoidal disturbance. We identify a particular case of the nonlinear regulator theory wherein the Byrnes–Isidori PDE has a simple solution. This case leads to a constructive procedure for designing nonlinear zero dynamics in systems with input disturbances. The constructive procedure is accessible to designers who do not have experience with the nonlinear geometric control theory. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26497&di [...]

Disturbance rejection in the control of a maglev artificial heart / Luca Gentili in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 130 N°1 (Janvier/Fevrier 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 10 p. Titre : Disturbance rejection in the control of a maglev artificial heart Type de document : texte imprimé Auteurs : Luca Gentili, Auteur ; Paden, Brad, Auteur ; Lorenzo Marconi, Auteur Année de publication : 2008 Article en page(s) : 10 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : maglev  artificial  heart;  advanced  controller Résumé : This paper is devoted to the development of an advanced controller for a maglev artificial heart: in particular, a magnetically levitated left ventricular assist device is studied and the disturbances from the natural heart are taken into account. The main goal is to define a control action able to reject dc as well as periodical disturbances from the control input in steady state. This is accomplished by exploiting the intrinsic instability of the system. The paper presents a couple of approaches for solving the problem: an internal model based approach and a solution based on adaptive observers. The internal model based solution relies on the knowledge of the frequencies of the sinusoidal disturbances affecting the system: this hypothesis is not far from the reality of the maglev apparatus as the shape and frequency of the quasiperiodic disturbance can be known with the addition of sensors. The design methodology based on the use of adaptive observers does not require the perfect knowledge of the frequencies of sinusoidal disturbances as an adaptive mechanism is presented to estimate them. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...] [article] Disturbance rejection in the control of a maglev artificial heart [texte imprimé] / Luca Gentili, Auteur ; Paden, Brad, Auteur ; Lorenzo Marconi, Auteur . - 2008 . - 10 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 130 N°1 (Janvier/Fevrier 2008) . - 10 p. Mots-clés : maglev  artificial  heart;  advanced  controller Résumé : This paper is devoted to the development of an advanced controller for a maglev artificial heart: in particular, a magnetically levitated left ventricular assist device is studied and the disturbances from the natural heart are taken into account. The main goal is to define a control action able to reject dc as well as periodical disturbances from the control input in steady state. This is accomplished by exploiting the intrinsic instability of the system. The paper presents a couple of approaches for solving the problem: an internal model based approach and a solution based on adaptive observers. The internal model based solution relies on the knowledge of the frequencies of the sinusoidal disturbances affecting the system: this hypothesis is not far from the reality of the maglev apparatus as the shape and frequency of the quasiperiodic disturbance can be known with the addition of sensors. The design methodology based on the use of adaptive observers does not require the perfect knowledge of the frequencies of sinusoidal disturbances as an adaptive mechanism is presented to estimate them. En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/issue.aspx?journalid=117&is [...]