Terrain-based landing site selection and path planning for fixed-wing UAVs

UAVs are used in several remote applications. While performing a mission, electro-mechanical faults can occur which requires the UAVs to land quickly and safely. Landing in emergency conditions is a time critical problem, where, the UAV needs to find a landing site and plan a path to the selected site that satisfies some safety criterion in a given time. In this paper, we use terrain information from digital elevation maps to find a list of potential landing sites, selecting a site from the list and determine a path to the selected site in a given time. We use two any time path planners - RRT and PSO for path planning in limited time and compare their performance. Simulation results are presented to validate our approach and an analysis on the effect of path cost, computational time and site selection is presented.