Adaptation of Lazy-Theta* for UAS 3D path planning considering safety costs

This paper presents a 3D path planning solution for UAS to obtain a safe and smooth path. The safety plays an important role in the missions with UAS surrounding or entering the buildings. The heuristic search algorithms are good candidates to address this problem. The Lazy Theta* algorithm has been modified to foster safety and smoothness maintaining a distance from obstacles of the environment. Modifications to consider a new cost component related to the distance to the obstacles are performed. Tests in a realistic environment are shown to evaluate how the modified algorithm computes safer and smoother paths. Moreover, a comparison with the A* algorithm, the A* algorithm considering the new cost component and the original Lazy Theta* is presented.