Standalone Fuzzy Logic Controller Applied to Greenhouse Horticulture Using Internet of Things

In this paper, a standalone Fuzzy Logic Controller (FLC) with Internet of Things (IoT) capabilities is developed for analysis and linguistic decision making about fertigation (fertilizers + water) in a greenhouse. The following input variables are evaluated: automatic drainage measuring, Electrical Conductivity (EC) and pH values of drainage. In order to determine if water content is easily available to crops, the lexical uncertainty given by "easily available" was quantified into a numerical value, as output is given a scalar value associated to fertigation. The result is a controller that embeds structural human knowledge about irrigation scheduling into an analytic FLC, in order to provide agricultural scientists with quick access to a particular crop's main production and growth related variables, and allowing for future data driven decisions on the spot. The controller was validated with real data collected from two particular crops, cucumber and greenpepper, using remote sensors connected to Internet. Final results seem support the continuing development of affordable yet efficient applications based on FLC and IoT, that provides effective production tools for horticulture producers in developing countries.