Digital and Analog Design of Fractional PD Controller for a Servo System

Paper presents two implementations of a fractional-order proportional-derivative (PD) controller for a position servo system. The first one is an analog one with the offered attractive benefit of using only one second-generation current conveyor (CCII) as an active element, minimizing the active component count compared to the conventional way of implementation where it requires three CCIIs for this purpose. The behavior of the controller is evaluated using the Cadence software and MOS transistor models. The second approach uses a digital implementation of Oustaloup filter in a time domain version.