| dc.description.abstract | Nutrient solution concentration in hydroponic crop cultivation need to be controlled to make it appropriate to the plant nutrient requirement. The purpose of this research is to design control system for nutrient solution concentrations using EC sensor, by using a PID method. This research was conducted in 4 stages; EC sensor calibration, simulation of decrease nutrient solution concentration caused by evapotranspiration process, determination of PID control parameter (Kp, Ki, Kd) with trial & error, and simulation of EC control of nutrient solution. Validation result of second stage was satisfied indicated by RMSE value at 0.025 grams with R2 value at 0.973. Then after conducted trial & error in determination of Kp, Ki, Kd obtained respectively 5, 5000, 200, with tolerance value ±6 %. Those value are the most optimal which is identified from settling time was 7.345 minute and steady state error was 0.025 dS/m. Simulation result of EC control of nutrient solution obtained RMSE value 0.023 dS/m and RMSE value from nitrogen mean weight 0.012 grams. Therefore, can be said this PID control system is in accordance with which expected. | en |
