Reachability-Based Forced Landing System

A major hurdle toward the integration of unmanned aerial systems into the civilian airspace is the development of a principled methodology for handling emergency landings. Most of the prior work in the area of emergency landings for unmanned aerial systems has been concerned with using computer vision to identify potential landing sites. However, reaching these sites may not be dynamically feasible, and the maneuver needed to reach these sites may not be obvious. In this paper, a reachability-based forced landing system is proposed that uses Hamilton-Jacobi-Bellman reachability to determine the feasible landing region of a distressed aircraft. The utility of this technique is displayed on a fixed-wing aircraft with engine failure. In addition, it is also shown how to synthesize a controller that guides the aircraft to any desired landing location inside the feasible landing region.