Turning of fractional-order phase-lead compensators: A graphical approach

This paper deals with the problem of graphical turning approach to fractional-order phase-lead compensators (FOPLC) for a class of all pole time-delay systems. The stabilization and phase-margin specification are considered, respectively, of this kind of delay systems using FOPLC, both based on a graphical stability criterion applicable to fractional-order time-delay systems. An algorithm for achieving the desired phase-margin is also proposed. Numerical examples are given to illustrate the shapes of the stabilizing region and to show the design procedure. The graphical turning method of FOPLC discussed in this paper exhibits the flexible property in selecting the parameters of FOPLC.