Angel Pontin Garcia

Development and simulation of an advanced system of ambient control in agricultural greenhouses.

Production in greenhouses is a technique that aims at protecting flowers and vegetable production against meteorological agents that affect production adversely, as well as allowing favorable environments throughout the year with productive and commercial advantages. One important issue regarding greenhouse systems is the control of the air temperature and relative humidity. The automatic environmental control allows the improvement of quality, and the efficient and rational use of resources. The aim of this work was to develop a system of temperature and humidity control for a greenhouse prototype in reduced scale, by using the concepts of Fuzzy Logic. The input variables were: air temperature and humidity, and the output variables were: changes in the environmental heating system and humidification. The environmental control was simulated and project parameters were adjusted. The results of the simulation showed that the air temperature and humidity adjustment based on the inference developed Fuzzy system, was satisfactory for the performance of the greenhouse environmental control.ABSTRACT Production in greenhouses is a technique that aims at protecting flowers and vegetable production against meteorologicalagents that affect production adversely, as well as allowing favorable environments throughout the year with productive andcommercial advantages. One important issue regarding greenhouse systems is the control of the air temperature and relativehumidity. The automatic environmental control allows the improvement of quality, and the efficient and rational use ofresources. The aim of this work was to develop a system of temperature and humidity control for a greenhouse prototype inreduced scale, by using the concepts of Fuzzy Logic. The input variables were: air temperature and humidity, and the outputvariables were: changes in the environmental heating system and humidification. The environmental control was simulatedand project parameters were adjusted. The results of the simulation showed that the air temperature and humidity adjustmentbased on the inference developed Fuzzy system, was satisfactory for the performance of the greenhouse environmental con-trol.

Dosador de fertilizante acionado eletricamente e controlado por lógica fuzzy

The present study shows the development, simulation and actual implementation of a closed-loop controller based on fuzzy logic that is able to regulate and standardize the mass flow of a helical fertilizer applicator. The control algorithm was developed using MATLABs Fuzzy Logic Toolbox. Both open and closed-loop simulations of the controller were performed in MATLABs Simulink environment. The instantaneous deviation of the mass flow from the set point (SP), its derivative, the equipment´s translation velocity and acceleration were all used as input signals for the controller, whereas the voltage of the applicators DC electric motor (DCEM) was driven by the controller as output signal. Calibration and validation of the rules and membership functions of the fuzzy logic were accomplished in the computer simulation phase, taking into account the systems response to SP changes. The mass flow variation coefficient, measured in experimental tests, ranged from 6.32 to 13.18%. The steady state error fell between -0.72 and 0.13g s-1 and the recorded average rise time of the system was 0.38 s. The implemented controller was able to both damp the oscillations in mass flow that are characteristic of helical fertilizer applicators, and to effectively respond to SP variations.

Plataforma multiuso eletromecânica para aplicações agrícolas

Resumo O objetivo geral deste estudo foi estabelecer a geometria de uma plataforma multiuso (chassis) não tripulada para processos agrícolas capaz de transpor os obstáculos presente no meio agrícola e sua otimização, com a finalidade de minimizar as forças máximas de atuação do sistema e maximizar a altura máxima de trabalho da plataforma a fim de contribuir no projeto de um veículo capaz de transitar em terrenos agrícolas.