Title: Metaheuristic control of substrate concentration for an activated sludge process

Authors: Fotis N. Koumboulis, Nikolaos D. Kouvakas, Maria P. Tzamtzi, Anna Stathaki

Addresses: Department of Automation, Halkis Institute of Technology, Psahna, Evia, 34400, Greece. ' Department of Automation, Halkis Institute of Technology, Psahna, Evia, 34400, Greece. ' Department of Automation, Halkis Institute of Technology, Psahna, Evia, 34400, Greece. ' Computer Technology Institute 10, Davaki Str., Ampelokipoi, Athens, 11526, Greece

Abstract: In this paper, a two-stage linear dynamic control scheme, using a metaheuristic approach, will be developed to control the effluent substrate concentration of an ASP. In the first stage, a static output feedback controller will be designed, using only measurements of the oxygen concentration. In the second stage, an asymptotic non-linear estimator of the substrate concentration will be used and the estimate will be fed back through a PI controller. In particular, the model of the ASP will be presented both in its non-linear and linearised form. Based on the linearised approximation, a static inner loop controller will be designed using a metaheuristic search algorithm for the computation of the controller parameters. Following, an outer PI controller will be designed based on the linearised model, again using a metaheuristic search algorithm in order to compensate the influence of the non-linearities when the static controller is applied to the non-linear model. The performance of the overall closed loop system will be illustrated through simulation experiments.

Keywords: output feedback control; wastewater treatment plants; metaheuristics; activated sludge; linear dynamic control; effluent substrate concentration; modelling; simulation.

DOI: 10.1504/IJMIC.2010.033854

International Journal of Modelling, Identification and Control, 2010 Vol.10 No.1/2, pp.117 - 125

Available online: 02 Jul 2010 *

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