An approach of firefly algorithm with modified brightness for PID and I-PD controllers of SISO systems

PID controller is widely used in the industrial processes. Proper tuning of PID controller improves the performance of feedback loop effectively. The effectiveness of any process control loop is determined initially by its physical structure. Now due to the evolvement of soft computing techniques the effective tuning can be achieved without altering its physical structure. Among all the metaheuristic algorithms firefly is the most desirable one due to its speed in finding the optimized point. In this paper two algorithms are proposed, both are based on firefly with a modification in the light intensity updation equation and the equation is defined for a three dimensional problem with different orientations. The first one—modified firefly is build on firefly and the second, is build on the hybrid algorithm—firefly algorithm with particle swarm optimization. The algorithm is investigated with the two structures namely PID and I-PD. The algorithms has been realized in MATLAB-Simulink environment. The objective functions considered here are peak overshoot (PO) and ITAE. The results are validated with four different systems and it is observed that in all the processes with the proposed updation equation the performance index, ITAE, is less independent of the structure. It is also understood that the PO, ISE, IAE and ITAE is less in the higher order systems.