Aportaciones al modelado y control climático de invernaderos

Abstract

Protected agriculture is a fundamental tool to support food security for a growing population in an environment of climate change and rational use of natural resources. Technication of protected agriculture allows increasing the productivity of crops, which has generated a productive gap between the technied facilities and those that are not. To decrease this disparity is not enough to transfer technology, in addition, it is necessary to develop technologies and techniques adapted to the microclimatic, socioeconomic and crop management conditions of the place where this type of facilities are implanted. Given its direct inuence on the productivity, quality and protability of the crop, greenhouse climatic control is one of the areas of protected agriculture which has presented a greater development. In recent years, eorts have been made in this ambit to develop technology in various related elds. Through this doctoral dissertation, contributions are made to the technication of protected agriculture in the areas of instrumentation, modeling and climate control. In the instrumentation area, low-cost monitoring and control systems are being developed as a relevant tool to modernize the low-tech facilities of small holders. In this sense, the methodology, implementation and testing of a low-cost psychrometers-network are described for monitoring the spatial variability of temperature and humidity inside a greenhouse. In relation to modeling, high and reduced order models, with simulation and control proposes are obtained. These structures t to the internal temperature dynamics of the tested greenhouse. Furthermore, a hybrid model of the inside temperature, which allows a formal representation of the interaction between dynamics of continuous and discrete variables of the system in cold weather, is obtained. Finally, in the climatic control area, feedforwad controllers obtained using new tuning-rules are developed and validated. These controllers compensate measurable disturbances before they aect the dynamics of the inside temperature. To regulate the nocturnal greenhouse temperature during winter, a hybrid model predictive controller is developed to regulate the temperature using a mixed heating system, consisting of a hot air heater and a hot water pipe one. This thesis has taken long time, where two research stays and countless online trials were made to obtain the results presented in this document. It is intended that the contributions presented here help to decrease the productive gap between technied and non-technied greenhouses, allowing their implementation in the latter ones.