Robust Fractional-Order Lag/Lead Compensators

this paper introduces a new design method of fractional-order robust lag/lead compensators. The proposed compensators are realizable and exhibit a frequency response of fractional-order dynamics. The structure of such controllers allows one to alternate between lag/lead forms by simply interchanging two parameters with each other. An analytical design method of these controllers is simplified to reduce the number of design parameters to two; the gain and one corner frequency of the compensator. It also ensures a robust flat phase response at their geometric mean, especially for those controllers of fractional-orders between 0.5 < alpha < 1. The proposed design method is straightforward and demonstrate a competitive performance to other existing ones as verified via set of numerical examples.