Vector-based tuning and experimental validation of fractional-order PI/PD controllers

Although a considerable amount of research has been carried out in the field of fractional-order controllers, a simplified tuning routine has yet to be established. Most of the tuning techniques for fractional-order controllers deal with complex computations and optimization routines. This paper proposes a simple yet efficient methodology based on a vector representation of the fractional-order controllers. This simplifies considerably the computations and derivation of the fractional-order controller parameters. The tuning procedure is exemplified first for a fractional-order PI controller designed for a simple first-order process, as well as for a fractional-order PD controller for a servoing system. In this case, the experimental results are also included, showing that this novel tuning approach is a viable replacement for the more complex tuning procedures currently employed in the design of different fractional-order controllers.