Robust control of transition maneuvers for a class of V/STOL aircraft

This work focuses on the control law design for a class of aerial systems able to perform transition maneuvers from hover to level flight configurations. An analysis of the aircraft dynamics and of the flight envelope of the vehicle, encompassing both the hover and the level flight conditions, is proposed in presence of wind disturbances. This analysis is used to derive a control strategy able to enforce the desired transition while maintaining the flight envelope within prescribed sets despite the influence of wind disturbances. To this end, a path following approach is adopted in which the time law is synthesized by a flight envelope protection controller. The paper complements our earlier work (Naldi & Marconi, 2011) in which optimal transition trajectories are computed. Simulation results, obtained with the parameters of a miniature tail-sitter prototype, show the effectiveness of the proposed approach.