Considerations about the choice of a differintegrator

Despite the great advances in the theory and applications of fractional calculus, some topics remain unclear making difficult its use in a systematic way. This paper studies the fractional differintegration definition problem from a systems point of view. Both local (Grunwald-Letnikov) and global (conventional) definitions are considered. It is shown that the Cauchy formulation must be adopted since it is coherent with usual practice in signal processing and control applications