Automated trajectory generation and airport selection for an emergency landing procedure of a CS23 aircraft

摘要

Aircraft in general aviation usually are operated in single pilot mode. Especially, in case of an incapability of the pilot to control the aircraft, an automated emergency procedure is desirable in order to reduce the risk of fatalities. The finding of a solution for an emergency landing maneuver includes preselecting possible landing sites with regard to the available aircraft capabilities and creation of feasible trajectories to these sites. A search tree in four-dimensional search space with an efficient implementation of a rapidly exploring random tree algorithm (RRT~*) is created. The algorithm performance is increased by use of basic geometrical sets to construct the final route as a combination of Dubins path segments. To further reduce the route length, a gradient based local optimization routine is added after completion of the RRT~* algorithm. At the moment of creation, terrain avoidance is verified and accordance with legal airspace structure is considered. An emergency procedure is created by combining a selected landing site and a flyable trajectory to this site. Each of these combinations is scored, and the most promising emergency landing procedure is chosen and delivered to flight management system of the aircraft. The flight management system controls a full-authority auto-flight system that is capable of performing en-route flight and auto-land procedures as well.