Abstract
Gain scheduling has proven to be a successful design methodology in many engineering applications. However, in the absence of a sound theoretical analysis, these designs come with no guarantees on the robustness, performance, or even nominal stability of the overall gain scheduled design. This paper presents such an analysis for two types of nonlinear gain scheduled control systems: 1) scheduling on a reference trajectory; and 2) scheduling on the plant output. Conditions are given which guarantee stability, robustness, and performance properties of the global gain scheduled designs.