Pole placement enhancement of a constrained greenhouse SISO system

Abstract

In this paper, we present an application of a pole placement technique related to the stability analysis for a linear constrained system. In this regard some of the main approaches that have been used in the last decades dealing with the pole placement will be engaged. Concepts and methods involved in this work include positive invariance as an efficient notion for the pole placement amelioration of a modern SISO system. The state feedback will enhance the stabily of the closed loop system under the notion of constrained control. For this aim, a greenhouse system, is engaged and a linear discrete time state space model, which fits properly the acquired data of the greenhouse, was identified by the mean of the subspace system identification (N4sid) algorithm. The obtained model will be used in order to develop and calculate the state feedback gain based on the so-called Sylvester algebric equation and one of the pole placement techniques algorithm to ameliorate the closedloop pole placement of the system with constraints on the control.