Fractional-order exponential switching technique to enhance sliding mode control

In this paper, a fractional-order sliding mode controller (FO SMC) based on an FO exponential switching technique and an FO proportional-integral (PI) switching surface is proposed for robust stabilization of uncertain FO nonlinear systems. The FO exponential switching technique, involving an FO sign function, is designed to guarantee the existence of the sliding motion in finite time. Reaching time is analytically derived and the reachability analysis is presented to explicate the superiority of the control performance. The stability analysis of sliding mode dynamics is performed relying on stable region analysis of FO systems. Simulation and practical results demonstrate the advantages of the designed control scheme.