Accurate design of digital rational approximations to the fractional order integrator using crow search algorithm

Abstract

This paper presents an accurate design of stable, minimum phase, and wideband digital rational approximations to the Fractional Order Integrators (FOIs) based on a recently proposed nature-inspired metaheuristic optimization approach motivated by the intelligent manners of crows called Crow Search Algorithm (CSA). The proposed CSA based Digital Fractional Order Integrators (DFOIs) are compared with those of the designs based on four well-known nature-inspired optimization algorithms in terms of different frequency response performance indices and computational efficiency. The CSA based design of filter orders 5 and 6 achieves improvement of 5.9 dB and 10.3 dB, respectively, over state-of-the-art designs in terms of root mean square magnitude error metric, and also demonstrates a competitive performance with respect to the phase response. The proposed work demonstrates that CSA can be considered as an efficient optimizer for the design of DFOIs.