µ Synthesis and LFT Gain Scheduling with Time Varying Mixed Uncertainties

This paper presents the solution to the mixed-¯ synthesis problem, and how to design gain scheduling controllers with linear fractional transformations (LFTs). The system is assumed to have parameter dependences described by LFTs. The goal of the controller is, with real-time knowledge of the parameters, to provide disturbance and error attenuation. The paper treats both complex and real parametric dependencies. Time-varying uncertainties with bounds on rate of variation can also be included in the same framework by left and right non-square multipliers that correspond to an augmented uncertainty structure