Performance/Robustness Limit Evaluation for Lyapunov-Stable Nonlinear Plants

Lyapunov-stable nonlinear plants can be approximated by an LTI model in many cases. If this approximation is obtained then it is possible to construct a G2DOF control system. The paper presents a new approach how the important relationships between the actuator, process and design parameters furthermore robustness measures can be determined. In this decomposition method the optimal control design for two-degree of freedom time delay control systems is discussed. Using a proper CAD algorithm the exact relationships can be plotted and the ultimate robustness limit of any control can be explicitly calculated.