Particle Swarm Optimization based design of disturbance rejection PID controllers for time delay systems

In this paper a new method to design PID controllers for time delay systems is presented. Particle Swarm Optimization (PSO) technique is used to obtain optimal parameters of a two-degree-of-freedom (2-DOF) PID controller. Set point tracking is an objective that is to be achieved in presence of disturbance. At first a PD controller as a disturbance rejection controller is designed, and then in the outer loop the main PID controller for tracking the input signal is placed. Since disturbance rejection and set point tracking should be satisfied alongside each other, some considerations are taken into account to choose the most appropriate controller. Using this method, a better response can be achieved in comparison with genetic algorithm.