Optimal Robust Tracxing in Discrete-Time Two-Parameter Control Systems under Nonlinear Time-Varying Uncertainties

A new robust stability condition is derived for analyzing the robustness property of discrete-time two-parameter control systems with nonlinear time-varying uncertainties. Based on the concept of excess robustness and the theory of minimum H^¿ norm, a feasible and effect design algorithm is presented to synthesize a two-parameter robust controller which ensures that discrete-time two-parameter control systems can achieve the object of optimal robust tracking in the face of nonlinear time-varying uncertainties.