Discrete and continuous fractional controllers

This article deals with a comparison of discrete and continuous fractional speed controller of DC motor with permanent magnets. The first part of this article deals with an introduction into fractional calculus with aim to software implementation of fractional controller. The discrete controller is based on direct use of Grunwald-Letnikov interpretation of fraction derivative. The continuous fractional controller is based on Oustaloup´s recursive approximation of fractional derivative. The second part deals with a comparison of both fractional controllers with a PI controller for DC motor with permanent magnets. Optimal parameters for all controllers are found by a genetic algorithm.