Development of an intelligent indoor environment and energy management system for greenhouses

The microclimate control in a greenhouse is a complicated procedure since the variables that influence it are several and dependant on each other. This work is an effort of integrating these variables in a common control methodology through the development of an intelligent environment and energy management system for greenhouses. Two fuzzy logic controllers are developed, embodying the expert knowledge of agriculturists and indoor environment experts. These controllers consist of fuzzy P (Proportional) and PD (Proportional-Derivative) control using desired indoor climatic set-points. The factors being monitored are the greenhouse’s indoor illuminance, temperature, relative humidity, CO2 concentration and the outside temperature. Output actuations include: heating units, motor-controlled windows, motor-controlled shading curtains, artificial lighting, CO2 enrichment bottles and water fogging valves. These controllers are prototyped in a Matlab environment and simulated using a greenhouse model, which is implemented as a module within the TRNSYS software. The system is tested in a greenhouse located in MAICh (Mediterranean Agronomic Institute of Chania). The overall installation is based on Local Operating Network (LonWorks) protocol.