Fuzzy control applied to the regulation of the temperature inside a greenhouse

Greenhouses are building structures that allow the creation of an indoor microclimate for crop development, protecting it from adverse outdoor conditions. Moreover this microclimate can be modified by artificial actuations such as heating, ventilation in order to provide the best environmental conditions. In this sense, several researchers used the optimal control and predictive control to develop algorithms which decide about heating and ventilation and produce temperature, humidity and carbon dioxide control actions (ref). In this paper, we are interested in the application of fuzzy control to this problem (references). The standard additive model (SAM) theorem extended to a class of nonlinear dynamical systems is used to represent the Exact Fuzzy model (TSK) of greenhouse, which is a nonlinear dynamical system ( ref.). The nonlinear plant is firstly approximated by a Takagi-Sugeno type fuzzy model, where the local dynamics in different state space regions are represented by linear models. The overall model of the system is achieved by fuzzy ”blending” of these linear models. In the control design, for each local linear model, a linear feedback control is designed. The resulting controller, is again a fuzzy blending of each of the individual linear controller (refer). The stability of the system is checked by sufficient conditions which call upon the tools LMIs (Linear Matrix Inequalities) (ref). This paper is presented as follows: In section