Comparison of various closed tuning rules on PID controller performance (LIQUID FLOW) / Nurul Aida Ghani

Flow control is essential in many chemical industries such as in dosing processes. Applications include the food and beverage industries, pharmaceutical industries, chemical research labs or pilot plants, and many more. PID controllers currently represent more than half of all controllers used in industry. However, in the absence of a mathematical model, the parameters must be determined experimentally. The method of determining the controller parameters that produce the desired output is referred to as controller tuning. Controller tuning enables process optimization by reducing the error between a process variable and its set point. The purpose of this study is to compare the effect of three different tuning rules on the performance of liquid flow process control. Open-loop test is carried out to obtain the process response curve which response rate (RR), time constant (Tc) and dead time (Td) was analysed using a Reformulated Tangent Method (RTM). The controller governing parameters, Proportional Band (PB)-Integral Time (I)-Derivative (D) are calculated using the established tuning rules in the literature; Ziegler-Nichols (Z-N) rule, Cohen-Coon (C-C) rule and Takahashi rule. The performance of the process response for each of the tuning rules is evaluated based on settling criteria such as settling time (Ts) and the quantity of the integral absolute error (IAE). The result presented that the Cohen-Coon (C-C) tuning method give a better performance compare to the Ziegler-Nichols (Z-N) rule and Takahashi rule.