Hybrid fuzzy plus PID controller of hydro-diffusion steam distillation essential oil extraction system: Design and performance evaluation

Abstract

Steam temperature of extraction plays a major role in steam distillation essential oil extraction. The process variable gives large effect to the output yield and quality of the oils. This study proposed a robust hybrid fuzzy combined with PID (HFPID) controller to control the steam temperature in the extraction process. The controller was attached to a hydro-diffusion to overcome the current issue facing by conventional steam distillation. The hydro-diffusion steam distillation plant enhances oil recovery by minimizing oil waste in boiling water. HFPID controller is expected to improve system performance at transient and steady state in order to promises the best quality of essential oil. The temperature control was achieved by controlling the voltage fed to the heater ranging from 0V to 5V via digital-to-analogue converter (DAC). The HFPID controller using 49 rules was compared with the conventional PID controller in term of rise time, settling time, percentage overshoot (%OS) and RMSE. From the result, the real time performance of HFPID controller reveals that this controller is compatible for the system because able to minimize the output error at transient state and gave the faster response with small overshoot, settling time and RMSE.