Robust takeoff and landing for a class of aerial robots

This paper focuses on the problem of robust takeoff and landing for a class of VTOL (Vertical Take-Off and Landing) aerial robots. One of the main challenge to be addressed derives from the fact that system dynamics may be remarkably different in case contacts with the landing surface happen or not. To this purpose an overall description of the system is obtained by considering the different behaviors and by defining a hybrid automaton. By taking explicitly into account the presence of possible model uncertainties and tracking errors in the definition of the reference trajectories, a control law is proposed which is shown to be able to achieve robustly the desired transitions between the hybrid states of the automaton. The solution described in the paper relies upon the general framework, for robust control of hybrid automata, described in the accompanying paper which, for reader´s convenience, is also briefly recalled here.