New Control Algorithm for Irrigation Hours of Green House1

Abstract

This thesis presents new technique of autonomous control for Greenhouse irrigation system. The control is used to manage the irrigations hours with the aim to reduce cost and increase plant growth performance. This unique control involves with loop signals through weather sensors which monitors the changes of weather condition. Three sensors namely temperature, humidity and pyranometer are used to provide signals that are known as multiplying factor for the control algorithm to perform autonomous adjustment for the next irrigation time. The algorithm involves with a constant K which is applied as time setting for daily irrigation. The time setting autonomously changed associated with the changes of weather such as dry climax, raining and hot weather. The control algorithm has been tested and the result shows the management of soil moisture through weather feedback element is economically improved and would be possible to increase yearly crop yield.