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Novel model - free approach for stiction compensation in control valves / Marco Antônio de Souza L. Cuadros in Industrial & engineering chemistry research, Vol. 51 N° 25 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8465–8476 Titre : Novel model - free approach for stiction compensation in control valves Type de document : texte imprimé Auteurs : Marco Antônio de Souza L. Cuadros, Auteur ; Celso J. Munaro, Auteur ; Saul Munareto, Auteur Année de publication : 2012 Article en page(s) : pp. 8465–8476 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Control  valves Résumé : Stiction in control valves is a frequent cause of loop performance deterioration. The solution is maintenance, but since plant shutdown to perform this task can take a long time, loop performance improvement through stiction compensation affords increased efficiency and profitability by reducing the necessity for unscheduled plant shutdowns. Non-model-based methods add compensating pulses to the control signal, thereby reducing process variability. However, the current practice of this strategy transfers variability to the control valve stem, degrading this actuator prematurely. In this paper, such methods are analyzed and a new method for reducing both process variability and valve stem actuation is proposed. The essence of this new method is to add the pulses only when they are required for reduction of process error. The compensation algorithm presented can handle set point changes and perturbations as is illustrated via simulation and through application to a pilot plant flow loop. The proposed method’s performance is measured using integral absolute error and valve reversal indexes. It produces better results than similar methods found in the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2015262 [article] Novel model - free approach for stiction compensation in control valves [texte imprimé] / Marco Antônio de Souza L. Cuadros, Auteur ; Celso J. Munaro, Auteur ; Saul Munareto, Auteur . - 2012 . - pp. 8465–8476. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 25 (Juin 2012) . - pp. 8465–8476 Mots-clés : Control  valves Résumé : Stiction in control valves is a frequent cause of loop performance deterioration. The solution is maintenance, but since plant shutdown to perform this task can take a long time, loop performance improvement through stiction compensation affords increased efficiency and profitability by reducing the necessity for unscheduled plant shutdowns. Non-model-based methods add compensating pulses to the control signal, thereby reducing process variability. However, the current practice of this strategy transfers variability to the control valve stem, degrading this actuator prematurely. In this paper, such methods are analyzed and a new method for reducing both process variability and valve stem actuation is proposed. The essence of this new method is to add the pulses only when they are required for reduction of process error. The compensation algorithm presented can handle set point changes and perturbations as is illustrated via simulation and through application to a pilot plant flow loop. The proposed method’s performance is measured using integral absolute error and valve reversal indexes. It produces better results than similar methods found in the literature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2015262