Stability analysis and tracking performance of fractional-order PI controller for a second-order oscillatory system with time-delay

The main aim of this paper is to present the analysis of stability regions and tracking performance for the closed-loop system with second-order plant with time-delay and continuous fractional-order PI controller. It is a trial to extend the results and methodology presented in [11] to non-integer order systems. The tracking performance is based on two quality indices IAE and ISE. The tuning method of fractional PI controller is with respect to Hermite-Biehler and Pontryagin Theorems.