Abstract

This paper presents an "explicit predictive control" with optimal performances of the heating system in a greenhouse. The main contribution of this work is to provide an offline solution of modeling and optimization in order to implement the control over a simple micro-controller without the need for computer. Based on a multi-model description of the temperature in a greenhouse, we represent this system in the Mixed Logical Dynamical (MLD) form using the modeling language (HYSDEL); once the MLD model of the system is determined, the equivalent Piecewise Affine (PWA) model is generated directly. The optimal control profile is a piecewise affine and continuous function based on a PWA model and an Explicit Model Predictive Controller , the aim of this control is to keep the temperature into a defined range, and in the same time reducing consumption and optimizing the number of switching of the heating control. Simulations with the proposed approach are presented and compared to the existing control; the results indicate a reduction of consumption between 17 and 44% according to the value of external temperature while the correspondent number of switching remains in acceptable margins

Keywords: Agricultural Greenhouse, Predictive control, Hybrid modeling: MLD and PWA, Predictive control, optimal control.

(P1110812004, 876KB) 

Biography:

Ibtissem Laribi Maatoug received the Engineer diploma  in Electrical Engineering from the National School of Engineering in Tunis (ENIT), and prepares a PhD degree at  INSAT of Tunisia. Her employment experience included the Siemens Tunisia Company, in the special fields of Industrial automation and supervision She is currently a Researcher at the laboratory of Automatic and applied Informatics "AIA" at INSAT of Tunisia. Her research interests include Hybrid system, constrained optimal control, model predictive control, and Industrial applications of automatic control.

Radhi Mhiri received his M.Sc.and PHD degrees in automatic control from the Tunis University (ENSET), Tunisia, in and his Habilitation in electrical engineering from the Tunis El Manar university (ENIT) , Tunisia 2000. Currently, he is full professor in the Department of Physics at Tunis El Manar University, Tunisia. He is collaborator member of the Center for Research in Higher Education (CRHE) at Sherbrooke university. He is the Head of a research group (AIA)  on automatic control at his university, he has published about 100 refereed journal and conference papers.  His current research interests include feedback control systems, and control theory, hybrid system, elearning.

BibTex

(P1110812004, 876KB)