Novel proportional–integral–derivative controller with second order filter for integrating processes

Many chemical and nonchemical processes exhibit integrating behavior. This paper presents new approach for deriving parameters of proportional–integral–derivative controller for various types of integrating processes. In order to obtain enhanced performance, the controller is augmented by a second order filter. In the process of deriving controller and filter parameters, time delay is approximated by second order Laguerre shift. Analytical tuning rules are derived on the basis of the sensitivity of loop transfer function. With the help of polynomial method, the poles are placed so as to minimize the overshoot in the servo response. A set point filter is also employed to mitigate the overshoot and settling time in servo response. Besides, the set point filter is able to decouple servo and regulatory responses. The proposed method is compared with recently proposed methods. The evaluation is carried out in terms of various performance indices. Investigation of evaluation results reveals that the proposed method offers considerable improvement over the existing methods.