Application of hybrid fuzzy plus PID for steam temperature control in hydro-diffusion essential oil extraction system

The hybrid fuzzy plus PID (HF+PID) controller using 3, 5 and 7 membership functions was implemented in hydro-diffusion essential oil extraction system. This controller was designed to regulate the steam temperature during extraction process for the purpose to achieve the desired target. In the extraction process, the temperature is very important variable that gives largest effect to the percentage yield and quality of the oils. Real time experiments were conducted and the performances were compared based on rise time, settling time, percentage overshoot and root mean square error (RMSE). In general, the intention to design HF+PID controller was achieved when the controller is able to drive the steam temperature to the desired set point.