A robust landing and sliding maneuver controller for a quadrotor vehicle on a sloped incline

This work addresses the design and experimental evaluation of a robust controller for a quadrotor landing maneuver comprising the approach to a landing slope and sliding on that slope, before coming to a complete halt. During the critical landing flight phase the dynamics of the vehicle change with the type of contact with the ground and a hybrid automaton, whose states reflect the several dynamic behaviors of the quadrotor, is employed to model the vehicle throughout the complete maneuver. The quadrotor landing problem is broken down into separate maneuver generation and robust trajectory tracking problems, which are combined to achieve a successful maneuver that is robust to possible uncertainties. Experimental results are provided to attest the feasibility of the proposed landing procedure.