Merging of air traffic flows

The problem of merging two or more flows of aircraft in a horizontal plane is considered. The aircraft aim to reach a target flow with the minimal amount of turning, while maintaining a given separation between them. Neither a priori sequencing nor scheduling of the merging aircraft is assumed. The individual trajectories for each aircraft are computed using optimization, and a subset of these optimal trajectories serve as a basis for merging multiple aircraft. A second optimization step produces trajectories for each aircraft to ensure both effective merging into the flow and sufficient separation. This generates the sequencing of the merging aircraft. Simulations of several merging scenarios illustrate the approach and show its results. A statistical study of the influence of the problem parameters on the success of the merging algorithm provides a guideline for the design of the airspace around the merging area. The proposed algorithm can be used for automatic en route and terminal area merging tasks within future more automated air traffic control systems.