Autonomous Parafoil Recovery Path Planning and Deployment Algorithm for Fixed-Wing UAVs

Abstract

Safe and accurate recovery of fixed-wing Unmanned Aerial Vehicles(UAVs) is a critical aspect of autonomous operations, especially
for systems designed for hand or catapult launch, which may lack landing gear. Under these conditions, parachute systems are often used for a safe landing, although using these systems for precise recovery in populated areas, high terrain, and water presents significant challenges. In addition, weather conditions have a major impact on the descent path post-parachute deployment, further complicating landing within the designated safe zones. Improper location and timing of parachute deployment may risk large errors or unsafe touchdown, increasing the need for precise parachute deployment location and timing. This study presents the development of an autonomous parafoil deployment and recovery path planning algorithm for fixed-wing UAVs. The proposed solution calculates the optimal parachute deployment point and generates a recovery trajectory that guides the UAV toward this point while ensuring appropriate deployment orientation with respect to the desired landing location. The algorithm integrates UAV flight states, the descent characteristics of the combined UAV-parachute system, and prevailing weather conditions to determine the deployment point and recovery trajectory. A simulation model of the algorithm, along with the UAV dynamic model, was developed in MATLAB/Simulink to investigate its performance. The results indicate that the proposed algorithm can improve UAV recovery strategies, minimising landing errors, and increasing operational safety within the considered simulation conditions. Future validation of the algorithm under real-world conditions may provide further insight into its reliability and lead to refinements in subsequent iterations.