Robust control design for a class of Unmanned Aerial Vehicle with parametric uncertainty

In this paper, the modeling and robust control design of a vertical flight attitude control for a mini tail-sitter with variable pitch propeller is discussed. Tail-sitters Vertical Take-off and Landing - Unmanned Aerial Vehicles (VTOL-UAVs) have operational flexibility of typical helicopters while having the cruise performance of fixed wing airplanes. The configuration proposed in this work is highly unstable in its natural flight state in vertical mode. A simplified dynamic model is presented and a robust control design to stabilize the decoupled attitude systems in presence of uncertainty and time-delay is developed. The results are supported by simulation tests.