Path Planning for Innovative Solutions Based on UAV-Helicopter Cooperation In HEMS Missions

The paper investigates the path-planning problem applied to an innovative UAV-helicopter cooperation system that aims at increasing safety during HEMS operations. The drone, that could be optionally launched by the helicopter, will have the mission to explore the area of operation to detect meteorological and physical obstacles. The combination of Rapidly-exploring Random Tree∗ as global planner and of Bidirectional Rapidly-exploring Random Tree as local planner is proved to provide a nearly-optimal global path and a rapid re-planning in case of new obstacles detection. The adoption of Savitzky-Golay filter enables trajectory smoothing, improving its practicability. The feasibility of the identified trajectory for a three-dimensional helicopter is assessed through computation of attitude and forces, the latter carried out by means of a multibody analysis software.