Non-integer differential or integral operators can be used to realize fractional-order controllers, which provide better performance than conventional PID controllers, especially if controlled plants are of non-integer-order. In many cases, fractional-order controllers are more flexible than PID and ensure robustness for high gain variations. This paper compares three different approaches to approximate fractional-order differentiators or integrators. Each approximation realizes a rational transfer function characterized by a sequence of interlaced minimum-phase zeros and stable poles. The frequency-domain comparison shows that best approximations have nearly the same zero-pole locations, even if they are obtained starting from different points of view.
Analog Realizations of Fractional-Order Integrators/Differentiators: A Comparison / Maione, Guido. - Vol. 3: Signal processing, systems modeling and control:(2009), pp. 184-189. (Intervento presentato al convegno 6th International Conference on Informatics in Control, Automation and Robotics (ICINCO 2009) tenutosi a Milano, Italy nel July 2-5, 2009).
Analog Realizations of Fractional-Order Integrators/Differentiators: A Comparison
MAIONE, Guido
2009-01-01
Abstract
Non-integer differential or integral operators can be used to realize fractional-order controllers, which provide better performance than conventional PID controllers, especially if controlled plants are of non-integer-order. In many cases, fractional-order controllers are more flexible than PID and ensure robustness for high gain variations. This paper compares three different approaches to approximate fractional-order differentiators or integrators. Each approximation realizes a rational transfer function characterized by a sequence of interlaced minimum-phase zeros and stable poles. The frequency-domain comparison shows that best approximations have nearly the same zero-pole locations, even if they are obtained starting from different points of view.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.