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

Abstract

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-toanalogue 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.

Real time robustness test evaluation performance for intelligent fuzzy controller in extraction process

“…The controller can be said to be robust if it is able to track the desired set point in all situations even when set point changes and can cause an abrupt disturbance during running process. The details of intelligent fuzzy controller configuration can be found in [3,[23][24][25][26]…”

“…It is very important to consider the robustness test as well as performance in control system design [1][2][3][4][5][6]. Generally, robustness test is applied to provide controller that can produce a smooth control response and also robust to any changes of the operation conditions during running process [7][8][9][10].…”

“…Many types of disturbances can be applied such as the increase of the water flow rate through the distillation column that can affect the process [7], a combination of white noise and sine-wave noise [11] and changes to the composition of raw materials. Numerous works applied the robustness test to check the capability and performance of their proposed controller for the process [3,[12][13][14][15][16].…”

“…The good controller is defined as a controller that could minimize the error between desired target and output in the steady-state manner [17]. The standard performance indexes used in the system's step response are percentage overshoot, rise time, settling time and accumulated error [3][4][5][6][7][18][19]. The percentage overshoot is the percentage of the maximum excess value versus the final value.…”

The study of dynamic response using ARX model in extraction process

“…It does also can produce more volume of oil as compared with the recent techniques such as superheated and soxhlet. During the extraction process, many significant parameters need to be consider such as temperature, size, extraction time, pressure and flow rate since its will give large effect in terms of quality and quantity [2,6]. Existing research stressed that the steam temperature is one of the most significant parameters that should give more attention since it will influence the production yield and quality [7][8].…”