Documents disponibles écrits par cet auteur

Measurement selection for engine transients by parameter signatures / James R. McCusker in Transactions of the ASME . Journal of engineering for gas turbines and power, Vol. 132 N° 12 (Décembre 2010) 

Public ISBD [article]  in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 12 (Décembre 2010) . - 10 p. Titre : Measurement selection for engine transients by parameter signatures Type de document : texte imprimé Auteurs : James R. McCusker, Auteur ; Danai, Kourosh, Auteur Année de publication : 2011 Article en page(s) : 10 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Fault  diagnosis  Jet  engines  Least  squares  approximations  Parameter  estimation  Wavelet  transforms Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A method of measurement selection is introduced that relies on parameter signatures to assess the identifiability of dynamic model parameters by different outputs. A parameter signature is a region in the time-scale plane wherein the sensitivity of the output with respect to one model parameter is much larger than the rest of the output sensitivities. Since a parameter signature can be extracted when the corresponding output sensitivity is independent of the others, the ability to extract parameter signatures is indicative of parameter identifiability by the output and used here for output/measurement selection. The purpose of this paper is to introduce a strategy for measurement selection by parameter signatures and to demonstrate its applicability to the transient decks of turbojet engines. The validity of the selected outputs in providing observability to all the engine model parameters is independently verified by successful estimation of parameters by nonlinear least-squares estimation. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...] [article] Measurement selection for engine transients by parameter signatures [texte imprimé] / James R. McCusker, Auteur ; Danai, Kourosh, Auteur . - 2011 . - 10 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of engineering for gas turbines and power > Vol. 132 N° 12 (Décembre 2010) . - 10 p. Mots-clés : Fault  diagnosis  Jet  engines  Least  squares  approximations  Parameter  estimation  Wavelet  transforms Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : A method of measurement selection is introduced that relies on parameter signatures to assess the identifiability of dynamic model parameters by different outputs. A parameter signature is a region in the time-scale plane wherein the sensitivity of the output with respect to one model parameter is much larger than the rest of the output sensitivities. Since a parameter signature can be extracted when the corresponding output sensitivity is independent of the others, the ability to extract parameter signatures is indicative of parameter identifiability by the output and used here for output/measurement selection. The purpose of this paper is to introduce a strategy for measurement selection by parameter signatures and to demonstrate its applicability to the transient decks of turbojet engines. The validity of the selected outputs in providing observability to all the engine model parameters is independently verified by successful estimation of parameters by nonlinear least-squares estimation. DEWEY : 620.1 ISSN : 0742-4795 En ligne : http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JETPEZ00013 [...]

Parameter estimation by parameter signature isolation in the time-scale domain / Danai, Kourosh 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) . - 11 p. Titre : Parameter estimation by parameter signature isolation in the time-scale domain Type de document : texte imprimé Auteurs : Danai, Kourosh, Auteur ; James R. McCusker, Auteur Année de publication : 2009 Article en page(s) : 11 p. Note générale : dynamic systems Langues : Anglais (eng) Mots-clés : iterative  parameter  estimation;  PARSIM;  Gauss–Newton  method Résumé : It is shown that output sensitivities of dynamic models can be better delineated in the time-scale domain. This enhanced delineation provides the capacity to isolate regions of the time-scale plane, coined as parameter signatures, wherein individual output sensitivities dominate the others. Due to this dominance, the prediction error can be attributed to the error of a single parameter at each parameter signature so as to enable estimation of each model parameter error separately. As a test of fidelity, the estimated parameter errors are evaluated in iterative parameter estimation in this paper. The proposed parameter signature isolation method (PARSIM) that uses the parameter error estimates for parameter estimation is shown to have an estimation precision comparable to that of the Gauss–Newton method. The transparency afforded by the parameter signatures, however, extends PARSIM’s features beyond rudimentary parameter estimation. One such potential feature is noise suppression by discounting the parameter error estimates obtained in the finer-scale (higher-frequency) regions of the time-scale plane. Another is the capacity to assess the observability of each output through the quality of parameter signatures it provides. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26497&di [...] [article] Parameter estimation by parameter signature isolation in the time-scale domain [texte imprimé] / Danai, Kourosh, Auteur ; James R. McCusker, Auteur . - 2009 . - 11 p. dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 131 N° 4 (Juillet 2009) . - 11 p. Mots-clés : iterative  parameter  estimation;  PARSIM;  Gauss–Newton  method Résumé : It is shown that output sensitivities of dynamic models can be better delineated in the time-scale domain. This enhanced delineation provides the capacity to isolate regions of the time-scale plane, coined as parameter signatures, wherein individual output sensitivities dominate the others. Due to this dominance, the prediction error can be attributed to the error of a single parameter at each parameter signature so as to enable estimation of each model parameter error separately. As a test of fidelity, the estimated parameter errors are evaluated in iterative parameter estimation in this paper. The proposed parameter signature isolation method (PARSIM) that uses the parameter error estimates for parameter estimation is shown to have an estimation precision comparable to that of the Gauss–Newton method. The transparency afforded by the parameter signatures, however, extends PARSIM’s features beyond rudimentary parameter estimation. One such potential feature is noise suppression by discounting the parameter error estimates obtained in the finer-scale (higher-frequency) regions of the time-scale plane. Another is the capacity to assess the observability of each output through the quality of parameter signatures it provides. DEWEY : 629.8 ISSN : 0022-0434 En ligne : http://dynamicsystems.asmedigitalcollection.asme.org/Issue.aspx?issueID=26497&di [...]