Predictive and Backstepping Control of Double Tank Process: A Comparative Study

ABSTRACT

This paper addresses the nonlinear control design problem for a state-coupled two-tank liquid-level system. For this system's dynamics, motivated by a desire to provide precise liquid-level control, two radically different control approaches are presented and compared: the model predictive control and the backstepping control. In the first proposed approach, a model-based predictive controller is designed for the two-tank liquid-level system that ensures exponentially stabilization for a particular class of second-order nonlinear system. Moreover, a robust controller based on a backstepping strategy is designed in order to ensure globally asymptotically stabilization for another particular class of second-order nonlinear systems. To ensure a suitable basis for their comparison, two different control methods are designed and verified with the same test setup. To highlight the efficiency and applicability of the proposed control schemes, theoretical comparisons as well as experimental results are provided and discussed.

KEYWORDS:

• Backstepping control
• Model predictive control
• Liquid-level control
• Nonlinear dynamics
• Stability
• Comparative study
• Test bench

Acknowledgements

This work was supported by the University of Monastir. This support is very gratefully acknowledged by the authors. Moreover, H. Gouta expresses appreciation for the fellowship from the Research Unit of Industrial Systems Study and Renewable Energy.

Additional information

Notes on contributors

Houssemeddine Gouta

Houssemeddine Gouta was born in Sousse, Tunisia, in July 1985. He received the Engineering diploma and the Master degree, respectively, in electrical engineering in 2009 and in automatic and signal processing in 2010 from the National School of Engineer of Tunis, Tunisia (L'Ecole Nationale d'Ingénieurs de Tunis ENIT). He is currently a PhD candidate at electrical engineering in National Engineering School of Monastir. His research interests are focused on nonlinear control, theoretical aspects of nonlinear observer design, and control of liquid-level systems.

E-mail: [email protected]

Salim Hadj Said

Salim Hajd Said received the MS degree in automatic and signal processing and the PhD degree in electrical engineering from National Engineering School of Tunis, in 2004 and 2009, respectively. He is currently an assistant professor of automatic at Preparatory Institute for Engineering Studies of Monastir, Tunisia. His research interests include state observation, predictive and adaptive control of linear and nonlinear systems.

E-mail: [email protected]

Faouzi M'sahli

Faouzi M'Sahli received the BS and MS degrees from ENSET, Tunis, Tunisia in 1987 and 1989, respectively. In 1995, he received the PhD degree in electrical engineering from ENIT, Tunisia. He is currently a professor of electrical engineering at National School of Engineers, Monastir, Tunisia. His research interests include modelling, identification, predictive and adaptive control of linear and nonlinear systems. He has published over 80 technical papers and co-author of a book “Identification et commande numérique des procédés industriels”, Technip editions, Paris.

E-mail: [email protected]