Robust adaptive inner-loop design for vehicles with uncertain dynamics

We present robust adaptive augmentation design for a class of 2^nd order uncertain nonlinear cascaded systems. These dynamics generalize the models that are often used for the design of inner-loop flight controllers. The proposed control architecture augments a baseline dynamic inversion controller with a direct adaptive component and a variable structure system, (VSS). While the adaptive augmentation is designed to maintain tracking performance in the presence of the system uncertainties, the VSS component protects the system trajectories from leaving allowable subset in the system state space. The design is applied to construct angle-of-attack (AOA) command tracking system for short period dynamics of a fixed wing aircraft.