It is well known that small electric Unmanned Aerial Vehicles (UAVs) suffer from low endurance problems. A possibility to extend the range of UAV missions could be to have a carrier drone with several lightweight multirotors aboard, which can take-off from and land on it. In this paper the challenging problem of Air-to-Air Automatic Landing (AAAL) of UAVs is solved by developing a strategy that combines a quasi-time optimal feedback and a hybrid logic to ensure a safe and fast landing. Eventually, the proposed algorithm is validated through experimental activities involving the landing of a small quadcopter on a bigger octocopter used as a carrier.

In this paper, the adaptive augmentation of the attitude control system for a multirotor unmanned aerial vehicle is considered. The proposed approach allows to combine a baseline controller with an adaptive one and to disable or enable the adaptive controller when needed, in order to take the advantages of both the controllers. To improve transient performance with respect to the standard model reference adaptive controller, an observed-based approach is exploited. The adaptation law is based on the error between the output of an observer of the nominal closed-loop dynamics and the actual output of the system with uncertainties. Experimental results obtained by testing the proposed approach on a quadrotor unmanned aerial vehicle are presented to compare the performance, in terms of disturbance rejection, with respect to the baseline controller and to a [Formula: see text] adaptive augmentation scheme.

Helicopter flight control law design including rotor state feedback is considered and an approach based on structured H∞ control, capable of guaranteeing stability and performance robustness, is proposed. The framework also encompasses fault tolerance with respect to failures of the rotor state sensors. Simulation results comparing the proposed approach to results from the literature are presented and discussed

No abstract

No abstract