Tuning of PID Controller Using SIMC Method for Systems with Time Delay and RHP Poles

Abstract

To control a class of system with RHP poles and time delay, a revised cascade control model is proposed in this work. This revised cascade control model aims to enhance both regulatory and servo performance of the system. Structurally, this proposed revised cascade control scheme has three controllers. To minimize the set point variations, an auxiliary controller is also used. An analytical method based on IMC design principle is used in designing the controller for set point tracing. It is developed using H2 optimization and Internal Model Control theory. Disturbance rejecter is developed as P + I + D controller. To make the set point tracking controller physically realizable, a low pass filter is cascaded with it. Simplified Internal Modal Control (SIMC) with only one adjustable parameter ‘ Tc ’ is used for tuning the controllers. The simulation studies for proposed approach are done using MATLAB/SIMULINK to demonstrate its effectiveness. This proposed revised cascade control scheme depicts 3-Degree of Freedom Control Structure.