title: Generalized predictive control for a coupled four tank MIMO system using a continuous-discrete time observer.
abstract: This paper deals with the problem of the observer based control design for a coupled four-tank liquid level system. For this MIMO system's dynamics, motivated by a desire to provide precise and sensorless liquid level control, a nonlinear predictive controller based on a continuous-discrete observer is presented. First, an analytical solution from the model predictive control (MPC) technique is developed for a particular class of nonlinear MIMO systems and its corresponding exponential stability is proven. Then, a high gain observer that runs in continuous-time with an output error correction time that is updated in a mixed continuous-discrete fashion is designed in order to estimate the liquid levels in the two upper tanks. The effectiveness of the designed control schemes are validated by two tests; The first one is maintaining a constant level in the first bottom tank while making the level in the second bottom tank to follow a sinusoidal reference signal. The second test is more difficult and it is made using two trapezoidal reference signals in order to see the decoupling performance of the system's outputs. Simulation and experimental results validate the objective of the paper.
authors.affiliation: Research Unit of Industrial Systems Study and Renewable Energy (ESIER), National Engineering School of Monastir (ENIM), University of Monastir, Ibn El Jazzar, 5019 Monastir, Tunisia. Electronic address: gouta.houssem@gmail.com.
authors.forename: Houssemeddine
authors.initials: H
authors.lastname: Gouta
authors.affiliation: Research Unit of Industrial Systems Study and Renewable Energy (ESIER), National Engineering School of Monastir (ENIM), University of Monastir, Ibn El Jazzar, 5019 Monastir, Tunisia. Electronic address: salim.hadjsaid@issig.rnu.tn.
authors.forename: Salim
authors.initials: S
authors.lastname: Hadj Saïd
authors.affiliation: Research Unit of Industrial Systems Study and Renewable Energy (ESIER), National Engineering School of Monastir (ENIM), University of Monastir, Ibn El Jazzar, 5019 Monastir, Tunisia. Electronic address: nabil.barhoumi@enim.rnu.tn.
authors.forename: Nabil
authors.initials: N
authors.lastname: Barhoumi
authors.affiliation: Research Unit of Industrial Systems Study and Renewable Energy (ESIER), National Engineering School of Monastir (ENIM), University of Monastir, Ibn El Jazzar, 5019 Monastir, Tunisia. Electronic address: faouzi.msahli@enim.rnu.tn.
authors.forename: Faouzi
authors.initials: F
authors.lastname: M'Sahli
keywords: Continuous-discrete time observer; Experimental validation; Exponential stability; Liquid level Control; Predictive Control; Sampled outputs