Control of Interval Systems Using 2DOF Configuration

This contribution is focused on continuous-time control of interval systems by means of two-degree-of-freedom (2DOF) configuration. The controller design utilizes algebraic techniques in the ring of proper and (Hurwitz-)stable rational functions (RPS). Robust stability of resulting 2DOF loops is analyzed graphically, namely with the assistance of the value set concept and the zero exclusion condition. In the presented illustrative example, a third order interval plant is robustly stabilized.