Автоматичне керування подачею живильного розчину в теплицях

Abstract

Today, the most common technology in winter greenhouses is to grow vegetables in low-volume hydroponics. With hydroponic technologies, all the necessary minerals of the plant are obtained from the nutrient solution, so deviations of acidity and concentration of mineral elements in the substrate and its humidity from optimal values lead to impaired plant uptake of nutrients and water, which can lead to plant diseases and death. Currently, the most common is software control of watering plants, but the loss of fertilizers and water is at least 25 %, which necessitates the creation of a system of automatic control of substrate humidity The aim of the work was to develop a system of automatic control of the supply of nutrient solution in greenhouses. To achieve this goal, a functional scheme of automatic humidity control of mineral wool was developed and the transfer functions of each of its links were determined. It is established that the most acceptable is the relay-pulse law of automatic regulation. As an indicator of quality in the optimization of the system of automatic humidity control of mineral wool, the total deviation was taken, which allowed to determine the pulse duration and quantization period by the time of the regulator, which are 111 and 666 s, respectively. The developed system of automatic regulation is stable and provides maintenance of humidity of mineral wool at the set level with an error which does not exceed 5 %