Automated Conflict Resolution for Air Traffic Control

This paper describes a conflict resolution algorithm that can provide automated separation assurance for the next generation air traffic control system. The algorithm generates resolution trajectories that can be sent to the aircraft from a ground-based system via data link. With suitable reconfiguration the algorithm can also be installed on board aircraft to support airborne separation assurance. It handles the complete spectrum of conflict types encountered in en route airspace, including ascents and descents to arrival fixes. The resolution trajectories are patterned after changes to flight plans (route changes), altitude clearances, and speed profiles that controllers customarily issue to pilots in resolving conflicts. The algorithm generates 4D resolution trajectories by evaluating successive alternative trial resolution maneuvers. Each conflict is first assigned a type category that determines a set of acceptable trial resolution maneuvers and the preferred maneuver aircraft. Then, a trajectory engine generates a 4D trajectory for each trial maneuver, and an associated conflict detector checks it to ensure it is conflict free. If it is not, the algorithm examines an alternative maneuver. This iterative process continues until a successful resolution is found. The resolution algorithm has been implemented and evaluated in a non-real time simulation, and its performance in resolving conflicts for a range of traffic levels is presented in this paper. Results indicate that the algorithm has the potential to resolve conflicts efficiently at significantly higher than current traffic levels.