A traffic complexity approach through cluster analysis Géraud Granger STERIA

The conflict resolution problem is quite simple as long as the number of aircraft involved is small. Many au-tomation projects disregarded the problem of clusters and failed on real traffic tests because they were unable to deal with complex conflicts. The first definition of cluster ap-peared in the middle of the nineties when theoretical re-search started on conflict resolution. The n-aircraft con-flict resolution problem is highly combinational and cannot be optimally solved using classical mathematical optimi-sation techniques. The set of admissible solutions is made of many unconnected subsets enclosing different local op-tima, but the subset enclosing the optimum cannot be found a priori. Using a priority order to solve a n-aircraft conflict is much easier but the solution is not optimal. However it is difficult to determine the best order or even a good order that ensures that a solution exists. In this paper, a theoreti-cal study of the possible structures of clusters is presented. A simulation using French real traffic data compares the structure of clusters with direct and standard routes. The sensitivity of cluster sizes to uncertainties on trajectories forecast is studied