Title: Designing fractional-order PIλDμ controller using differential harmony search algorithm

Authors: Gourab Ghosh Roy, Prithwish Chakraborty, Swagatam Das

Addresses: Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata, 700032, India. ' Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata, 700032, India. ' Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata, 700032, India

Abstract: Harmony Search (HS) has recently emerged as an efficient metaheuristic algorithm that draws inspiration from the music improvisation process. This article describes the design of fractional-order proportional-integral-derivative (FOPID) controllers, using a newly developed variant of HS, known as differential harmony search (DHS). Design of FOPID controllers is more complex than that of conventional integer-order PID controller since the latter involves only three parameters while the former involves five parameters to tune. Controller synthesis is based on user specifications like peak overshoot and, rise time; which are used to formulate a single objective optimisation problem. Tustin operator-based continuous fraction expansion (CFE) scheme was used to digitally realise fractional-order closed loop transfer function of the designed plant-controller setup. Experimental results of comparison between DHS and a few established optimisation techniques [particle swarm optimisation (PSO) and genetic algorithm (GA)] over different instantiations of the design problem reflect the superiority of the proposed methodology.

Keywords: differential harmony search; DHS; fractional-order PID controllers; particle swarm optimisation; PSO; genetic algorithms; continuous fraction expansion; closed loop transfer; plant control.

DOI: 10.1504/IJBIC.2010.036156

International Journal of Bio-Inspired Computation, 2010 Vol.2 No.5, pp.303 - 309

Available online: 25 Oct 2010 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article