Design of PID controller based on reduced order model and Characteristic Ratio Assignment method

This paper presents design of PID controller using Characteristic Ratio Assignment (CRA) method. The design methodology uses reduced first order plus delay time (FOPDT) model of system. Based on required overshoot and settling time the controller parameters are computed using CRA method. To demonstrate the performance and stability of controller simulation examples are presented. To indicate the robustness of the controller the 20% uncertainty is added to the system model and controller performance is evaluated. To show the real life applicability of the proposed controller a real life flow control system is used for the demonstration. The performance of the proposed controller is compared with a PID controller in the literature.