DC-motor velocity control using a robust fractionalized adaptive PI controller

Fractional order adaptive controllers are gathering a great interest in the control research community mainly because of the additional tools and freedom offered to the designer in order to respond to more severe control specifications, for processes under control in real-time. The present work introduce a new innovation for a particular regulator in this class of controllers namely the classical adaptive PI controller scheme by the `fractionalization´ of the integer order integrator in the system control loop. This technique allows us to introduce fractional order filters in the original control system to improve the robustness of the process against noises and disturbances. We show that the noise rejection rate can be augmented to more than 50% by using this methodology. A numerical example of velocity regulation for a DC-Motor is presented to illustrate this improvement in robustness.