Geofencing for Optionally Piloted Aircraft Through Automatic Execution of Smooth Evasive Maneuvers

The paper proposes a method for generating and automatically executing smooth evasive maneuvers which allow to enforce a geofence for an optionally piloted fixed-wing aircraft. Feasible trajectories are planned online based on the current aircraft state and performance limitations, including finite roll rates. Collision checks are continuously carried out in the background to take over control from the pilot before violating the geofence becomes inevitable. The system automatically executes an evasive maneuver before giving back control to the pilot. The approach can readily be applied to the general collision avoidance problem for convex obstacles. We validate the feasibility and geofencing accuracy of the proposed framework by showcasing results of flight tests of an unmanned, fixed-wing aircraft.