Event-based control for a greenhouse irrigation system

Abstract

This work presents a simulation study of an event-based predictive control system for a greenhouse irrigation process. The control system objective is to maintain the desired humidity level, keeping the water usage as low as possible. The event-based control scheme uses a crop transpiration model and a water content virtual sensor to trigger the irrigation system events. In such a scheme, the event-based controller determines the volume of water required to compensate for the irrigation system disturbances. Simulation experiments were performed to analyze the behavior of the designed system and to study the water supply dynamics to the substrate and subsequent drainage and evaporation. The resulting control system is able to adapt the actuation rate to the state of the plant providing the efficient way of water consumption. The obtained results show that application of proposed event-based approach for the greenhouse irrigation system allows us to improve the control performance and to reduce the water usage being an important issue in intensive agriculture. The improved control performance is obtained due to event-based approach and the inclusion of information about the plant dynamic response for water supply and transpiration effect.