International Journal of Engineering and Technology

This paper proposes a study on heuristic algorithms based PID controller design for a class of Single Input Single Output (SISO) and Two Input and Two Output (TITO) systems. In this work, well known heuristic methods such as Particle Swarm Optimization (PSO), Improved PSO (IPSO), Bacterial Foraging Optimization (BFO), hybrid algorithm (PSO+BFO) and Firefly Algorithm (FA) are chosen to find the optimal Kp, Ki, Kd values based on the chosen SISO and TITO process models. For the SISO systems, the well known PID and set-point filter based PID controllers are implemented and for the TITO process models, a decentralised PID controller design is proposed. In this work, the optimization process is focused to search the best possible controller parameters (Kp, Ki, Kd) by minimizing the multi objective performance index chosen to guide the heuristic search. The effectiveness of the proposed scheme has been confirmed through a comparative study with heuristic procedures and the classical controller tuning methods proposed in the literature. The results show that, heuristic algorithm assisted approach provides enhanced performance in effective reference tracking with minimal ISE and IAE values. Finally the robustness of the SISO system is validated by operating the unstable systems in the presence of a measurement noise. The results testify that the PSO-BFO tuned set-point filter based PID performs well in tracking the change in reference signal even in the noisy environment. The FA based procedure on the TITO system also offered better result on the TITO process compared with others approaches existing in the literature.