Robust Adaptive Control of a Quadruple Tank Process with Sliding Mode and Pole Placement Control Strategies

Abstract

Many industrial processes have challenging issues such as complex nonlinear nature, high sensitivity to disturbances and existence of parametric uncertainties. A Quadruple Tank Process (QTP) is used in the laboratory as a scaled representation of many industrial processes involving liquid level control problems. Conventional controllers are relatively slow in tracking the reference inputs and in reacting to disturbances, and they tend to lack the ability in dealing with parametric changes in the QTP. The aim of this paper is to design and test an Adaptive Pole Placement Controller (APPC) and a robust Adaptive Sliding Mode Controller (ASMC) with the purpose of high-efficacy control of a minimum phase QTP. The controllers are tested via simulations and performance indices resulting from the simulation of these controllers are compared with a PID controller in terms of the three cases of robustness to set point variations, rejection of disturbance inputs, and robustness to parametric uncertainties. Simulation results reveal that the proposed adaptive control configurations perform better than the PID controller with lower performance indices and faster settling times due to the paramater estimation method used in the design processes. ASMC outperforms APPC in different variations of inputs and in regulation performances due to the invariant nature of the Sliding Mode Control (SMC). The results show that a decentralized ASMC can be used to improve the rapidity and robustness of many multivariable industrial process control systems.

KEYWORDS:

• Adaptive sliding mode control
• Decentralized control
• Disturbance rejection
• Error indices
• Pole placement adaptive continous control
• Robust control
• Uncertainty

Acknowledgement

The research is sponsored by Turkey Government Scholarships for International Students (YTB).

Additional information

Notes on contributors

Alhassan Osman

Alhassan Osman was born in Wa, Ghana on 16 May, 1987. He received the BSc and MSc degrees in electrical and electronics engineering from the University of Boumerdes, Algeria. He is currently pursuing PhD in control engineering at Gaziantep University, Turkey.

Tolgay Kara

Tolgay Kara received the BS degree in electrical and electronics engineering from the Middle East Technical University (METU) at Ankara, Turkey, and MS and PhD degrees in control engineering from the Department of Electrical and Electronics Engineering, Gaziantep University at Gaziantep, Turkey. He currently works as associate professor and holds the position of division head at the Control Systems Division, Department of Electrical and Electronics Engineering, Gaziantep University. Email: [email protected]

Mehmet Arıcı

Mehmet Arıcı was born in Oguzeli, Gaziantep, Turkey on 21 September 1986. He obtained his BSc degree in electical and electronics engineering from Karadeniz Technical University in 2010. He obtained MSc and PhD degrees in electrical and electronics engineering from Gaziantep University in 2013 and 2019, respectively. Presently, he is assistant professor in the Department of Electircal and Electronics Engineering, Gaziantep Islam, Science and Technology, Gaziantep, Turkey. His current research area includes fault tolerant control systems, adaptive control, control of robot manipulators, and process systems. Email: [email protected]