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Vol: 51(65) No: 2 / June 2006 State Estimation of a Wastewater Treatment Process Using a Sliding-Mode Observer Marian Barbu Department of Automatic Control, "Dunarea de Jos" University of Galati, Domneasca Street No.47, 800008 Galati, Romania, phone: (+40) 236-460182, e-mail: Marian.Barbu@ugal.ro Sergiu Caraman Department of Automatic Control, "Dunarea de Jos" University of Galati, Domneasca Street No.47, 800008 Galati, Romania, phone: (+40) 236-460182, e-mail: Sergiu.Caraman@ugal.ro Keywords: state estimation, sliding mode, equivalent control, wastewater treatment, activated sludge. Abstract This paper deals with the state estimator process in the field of wastewater treatment with activated sludge. As is very well known, literature shows that the wastewater treatment processes are characterized by parametric uncertainties and measuring noise. In the present paper a robust method for non-linear systems state estimation is used: the sliding-mode observer. This kind of observer was developed based on the equivalent control method and it has an important advantage: the necessity of tuning a small number of parameters. References [1] M. Barbu, S. Caraman and E. Ceangă, “Stochastic Estimation Techniques for Biotechnological Processesâ€, Control Engineering and Applied Informatics, vol. 6, no. 4, pp. 43-51, 2004. [2] M. Barbu and S. Caraman, “Sliding-Mode Observer for a Wastewater Treatment Processâ€, Proceedings of the 7th International Conference On Technical Informatics, CONTI 2006, vol. 1, pp. 67-70, Timisoara, Romania, June 8-9, 2006. [3] J.P. Barbot, M. Djemai and T. Boukhobza, “Sliding Mode Observersâ€, In: Sliding Mode Control in Engineering, Editors: W. Perruquetti and J.P. Barbot, Marcel Dekker Inc, 2002. [4] G. Bastin and D. Dochain, On-line Estimation and Adaptive Control of Bioreactors, Elsevier, 1990. [5] S. Caraman and M. Barbu, Modelarea si conducerea proceselor biotehnologice. Lucrari practice. Volumul 1: Modelarea si estimarea starii si parametrilor proceselor biotehnologice, Editura Fundatiei Universitatii „Dunarea de Jos†din Galati, 2005. [6] S. Drakunov, “Sliding Mode Observers Based on Equivalent Control Methodâ€, Proceedings of the 31st IEEE Conference on Decision and Control, pp. 2368-2369, Tucson, Arizona, 1992. [7] S. Drakunov and U. Ozguner, “Descentralized Sliding Observers for Interconnected Nonlinear Systemsâ€, Proceedings of the IEEE International Workshop on Variable Structure and Lyapunov Control of Uncertain Dynamical Systems, Sheffield, England, 1992. [8] S. Drakunov and V.I. Utkin, Sliding Mode Observers. Tutorial, Proceedings of the 34th IEEE Conference on Decision and Control, pp. 3376-3378, New Orleans, 1995. [9] P. Georgieva and A. Ilchmann, “Adaptive l-tracking control of activated sludge processesâ€, Internation Journl of Control, vol. 74, no. 12, pp. 1247-1259, 2001. [10] P. Ingildsen, Realising Full-Scale Control in Wastewater Treatment Systems Using In Situ Nutrient Sensors, Ph.D. Thesis, Department of Industrial Electrical Engineering and Automation, Lund University, Sweden, 2002. [11] F. Nejjari et al., “Non-linear multivariable adaptive control of an activated sludge wastewater treatment processâ€, International Journal of Adaptive Control and Signal Processing, vol. 13, no. 5, pp. 347-365, 1999. [12] D. Selişteanu, Modelarea şi conducerea bioreactoarelor, Editura Universitarea, Craiova, 2001. |