Geofence Compliance Maneuvers for Fixed-Wing Uncrewed Aerial Vehicles

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, the 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 and clothoid–arc–clothoid paths while respecting the UAV’s roll constraints. An analytical formulation is developed to design the maximum allowable clothoid sharpness and the optimal extent of the circular arc, expressed as explicit functions of the UAV’s roll constraints, to minimize the proximity distance required for safe geofence avoidance. The proposed framework is also integrated into an area coverage mission to enable real-time triggering of evasive maneuvers upon detecting proximity to geofence boundaries. The effectiveness of the proposed method is validated through numerical simulations.