Nutrient Concentration Control System in Hydroponic Plants Based on Fuzzy Logic

The purpose of this study was to control nutrient concentrations in hydroponic plants according to predetermined values. If the density is high, dilution is needed, whereas if the density is low, additional nutrients are needed. So far, nutrient concentration monitoring has been carried out using a Total Dissolve Solid (TDS) measuring instrument and done manually. So that if there is a delay, lack or excess of nutrition and water, it will result in not optimal plant growth. The control system uses a controller based on fuzzy logic with the Sugeno method. The input of the controller is error and delta error, while the output of the controller will adjust the angle of the servo motor that drives the nutrient and water valve openings. The test results with an initial concentration value of 400 ppm (below the set point) obtained a settling time at 138 seconds, while the set point was reached at 157 seconds where the output value was 601.26 ppm. For testing with an initial concentration value of 700 ppm (above the set point), the settling time was obtained at 76 seconds and the set point was reached at 143 seconds, namely 601.45 ppm. The system achieves control objectives using a designed fuzzy logic controller