Geofence Compliance Maneuvers for Fixed-Wing UAVs

Geofencing is essential for ensuring the safe and regulated operation of Uncrewed Aerial Vehicles (UAVs) within designated airspaces. For fixed-wing UAVs, which operate under roll angle and roll rate limitations, early detection of potential geofence boundary violations and timely generation of dynamically feasible evasive trajectories are critical. This paper presents a real-time trajectory generation framework that produces curvature-continuous evasive maneuvers using clothoid–clothoid paths, while respecting the UAV’s roll constraints. Analytical expressions are derived for the maximum allowable clothoid sharpness and the minimum proximity distance required for safe geofence avoidance. The effectiveness of the proposed method is demonstrated through numerical simulations.