Robust Delay-Dependent Output-Feedback PD Controller Design for Variable Fractional-Order Uncertain Neutral Systems With Time-Varying Delays

This article is focused on the stabilization and control of variable fractional-order (VFO) neutral delay systems with time-varying structured uncertainties and delays. Using the Lyapunov theorem, the delay-and order-dependent stability criterion of both the nominal and uncertain VFO systems of neutral-type with time-varying delays are derived using a set of linear matrix inequalities (LMIs). An LMI-based output-feedback proportional–derivative (PD) control law that meets the delay-dependent and order-dependent criteria is then derived to guarantee the asymptotic stability of such systems. The performance of the proposed control structure is assessed using a simulation study of two VFO systems.