Documents disponibles écrits par cet auteur

Decentralized PID controllers based on probabilistic robustness / Chuanfeng Wang in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 133 N° 6 (Novembre 2011) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 133 N° 6 (Novembre 2011) . - 08 p. Titre : Decentralized PID controllers based on probabilistic robustness Type de document : texte imprimé Auteurs : Chuanfeng Wang, Auteur ; Donghai Li, Auteur Année de publication : 2012 Article en page(s) : 08 p. Note générale : Dynamic systems Langues : Anglais (eng) Mots-clés : Chemical  engineering  Control  system  synthesis  Decentralised  control  Genetic  algorithms  MIMO  systems  Monte  Carlo  methods  Multivariable  control  systems  Probability  Robust  control  Three-term  control Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : A tuning method for decentralized PID controllers was developed based on probabilistic robustness for multi-input-multi-output plants, whose parameters vary in a determinate area. The advantage of this method is that the entire uncertainty parameter space can be considered for controller designing. According to model uncertainties, the probabilities of satisfaction for every item of dynamic performance requirements were computed and synthesized as the cost function of genetic algorithms, which was used to optimize the parameters of decentralized PID controllers. Monte Carlo experiments were used to test the control system robustness. Simulations for five multivariable chemical processes were carried out. Comparisons with a standard design method based on nominal conditions indicate that the method presented in this paper has better robustness, and the systems can satisfy the design requirements in a maximal probability. DEWEY : 553 ISSN : 0022-0434 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA000133000006 [...] [article] Decentralized PID controllers based on probabilistic robustness [texte imprimé] / Chuanfeng Wang, Auteur ; Donghai Li, Auteur . - 2012 . - 08 p. Dynamic systems Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 133 N° 6 (Novembre 2011) . - 08 p. Mots-clés : Chemical  engineering  Control  system  synthesis  Decentralised  control  Genetic  algorithms  MIMO  systems  Monte  Carlo  methods  Multivariable  control  systems  Probability  Robust  control  Three-term  control Index. décimale : 553 Géologie économique. Minérographie. Minéraux. Formation et gisements de minerais Résumé : A tuning method for decentralized PID controllers was developed based on probabilistic robustness for multi-input-multi-output plants, whose parameters vary in a determinate area. The advantage of this method is that the entire uncertainty parameter space can be considered for controller designing. According to model uncertainties, the probabilities of satisfaction for every item of dynamic performance requirements were computed and synthesized as the cost function of genetic algorithms, which was used to optimize the parameters of decentralized PID controllers. Monte Carlo experiments were used to test the control system robustness. Simulations for five multivariable chemical processes were carried out. Comparisons with a standard design method based on nominal conditions indicate that the method presented in this paper has better robustness, and the systems can satisfy the design requirements in a maximal probability. DEWEY : 553 ISSN : 0022-0434 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JDSMAA000133000006 [...]

Stability of frictional sliding with the coefficient of friction depended on the temperature / Vahid Mortazavi in Transactions of the ASME . Journal of tribology, Vol. 134 N° 04 (Octobre 2012) 

Public ISBD [article]  in Transactions of the ASME . Journal of tribology > Vol. 134 N° 04 (Octobre 2012) . - 07 p. Titre : Stability of frictional sliding with the coefficient of friction depended on the temperature Type de document : texte imprimé Auteurs : Vahid Mortazavi, Auteur ; Chuanfeng Wang, Auteur ; Michael Nosonovsky, Auteur Année de publication : 2012 Article en page(s) : 07 p. Note générale : tribology Langues : Anglais (eng) Mots-clés : Friction-induced  instabilities;  stability  criterion;  thermal  conductivity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Friction-induced instabilities can be caused by different separate mechanisms such as elastodynamic or thermoelastic. This paper suggests another type of instability due to the temperature dependency of the coefficient of friction. The perturbations imposed on the surface temperature field during the frictional sliding can grow or decay. A stability criterion is formulated and a case study of a brake disk is performed with a simple model without including effects of transforming layer and chemical/physical properties change with temperature. The disk is rigid and the coefficient of friction depends on temperature. We show that the mechanism of instability can contribute to poor reproducibility of aircraft disk brake tests reported in the literature. We propose a method to increase the reproducibility by dividing the disk into several sectors with decreased thermal conductivity between the sectors. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE9000134000004 [...] [article] Stability of frictional sliding with the coefficient of friction depended on the temperature [texte imprimé] / Vahid Mortazavi, Auteur ; Chuanfeng Wang, Auteur ; Michael Nosonovsky, Auteur . - 2012 . - 07 p. tribology Langues : Anglais (eng) in Transactions of the ASME . Journal of tribology > Vol. 134 N° 04 (Octobre 2012) . - 07 p. Mots-clés : Friction-induced  instabilities;  stability  criterion;  thermal  conductivity Index. décimale : 621.5 Energie pneumatique. Machinerie et outils. Réfrigération Résumé : Friction-induced instabilities can be caused by different separate mechanisms such as elastodynamic or thermoelastic. This paper suggests another type of instability due to the temperature dependency of the coefficient of friction. The perturbations imposed on the surface temperature field during the frictional sliding can grow or decay. A stability criterion is formulated and a case study of a brake disk is performed with a simple model without including effects of transforming layer and chemical/physical properties change with temperature. The disk is rigid and the coefficient of friction depends on temperature. We show that the mechanism of instability can contribute to poor reproducibility of aircraft disk brake tests reported in the literature. We propose a method to increase the reproducibility by dividing the disk into several sectors with decreased thermal conductivity between the sectors. DEWEY : 621.5 ISSN : 0742-4787 En ligne : http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JOTRE9000134000004 [...]