Guaranteed properties for nonlinear gain scheduled control systems

An analysis is presented of two types of nonlinear gain-scheduled control systems: scheduling on a reference trajectory and scheduling on the plant output. Conditions are given which guarantee stability, robustness, and performance properties of the global gain-scheduled designs. These conditions confirm and formalize popular notions regarding gain-scheduled designs, e.g., that the scheduling variable should vary slowly and capture the plant´s nonlinearities. These results extend previous work by the authors which addressed the case of linear plants whose dynamics depend on exogenous parameters