Direct Tuning Method for Optimization of PID and I-PD Parameters

Abstract

Existing work proposed a new and practical approach of tuning of a controller in a closed-loop process plant. The approach is a direct tuning method, termed as Extended Fictitious Reference Iterative Tuning (E-FRIT). Now, we propose to generate the reference model from the closed-loop data, where the order of the reference model is decided based on the process dynamics of the closed-loop data. That makes the model maximum possible fit on the actual data. This is applicable to both proportional integral derivative (PID) and I-PD controller tuning. The application of this E-FRIT method is presented with a continuous stirred tank reactor (CSTR) case study. Also, a comparative study has been done on the models developed using closed-loop data & models assumed as first-order plus time delay system (FOPTD) or second-order plus time delay system (SOPTD).

Keywords: E-FRIT, PID parameters, I-PD parameters, optimization, CSTR