Process controllability for flow control system using Ziegler-Nichols (ZN), Cohen-Coon (CC) and Chien-Hrones-Reswick (CHR) tuning methods

The controllability of the process depends on the values need to be chosen for the proportional, integral and derivative constants. The value of proportional, integral and derivative can be estimated using various tuning method. The purpose of this study is to compare the performance of various proportional, integral and derivative controller tuning methods for flow control system. A Tangent Method and Reformulation Tangent Method were compared in this paper to perform the open-loop test. From the open-loop test, the value of response rate, dead time and time constant were obtained. The controller parameters from open-loop test were used in tuning rule to get the optimum value of proportional, integral and derivative gains. The tuning methods used in this paper were Ziegler-Nichols, Cohen-Coon and Chien-Hrones-Reswick. Performance comparison and analysis of the three proportional, integral and derivative tuning were based on percent overshoot, settling time, rise time and integral absolute error. The fine tuning technique has used to improve the result which the value of proportional and integral gains were tuned. The result showed that Ziegler-Nichols and Chien-Hrones-Reswick tuning methods provided better performance compared to CC tuning method.