Rémy Fondacci

Combinatorial Issues in Air Traffic Optimization

The current airway network used by aircraft is composed of a set of segments that intersect on special points defined by radio beacons emitting signals from the ground. This network leads to excess flight length, which for the European network is estimated to be 8%. In the near future, the Global Positioning System, which can determine precisely the location of aircraft, might allow the design of a network without using any ground fixed radio beacons. Therefore, we can project a new skyway network with straight airways between airports, allowing an airway to change level one or more times between its origin and destination to avoid potential conflict points. We present some segment set combinatorial issues to achieve such a network. In particular, we propose heuristics or algorithms for the problems of the maximum clique, the coloring, the N-coloring, and other more general problems of coloring of a set of segments. Finally, we discuss some results based on actual data analysis.

A 4D-sequencing approach for air traffic management

The current air traffic system is forecasted to face strong challenges due to the continuous increase in air traffic demand. Hence, there is a need for new types of organization permitting a more efficient air traffic management, with both a high capacity and a high level of safety, and possibly with a reduced environmental impact. In this article, we study a holistic approach, consisting in designing across Europe a very organized air traffic system, as opposed to free flight, to reduce costs while maintaining safety.

Using graph concepts to assess the feasibility of a sequenced air traffic flow with low conflict rate

In this paper, we propose to study feasibility issues of a new air traffic paradigm. In this paradigm, aircraft are following immaterial moving points in such a way that no conflict (or at most few) occurs between aircraft. We provide lower and upper bounds on the maximum density of a solution. In particular, we characterize the density of the solution according to the colorability of an auxiliary graph, modelling the potential conflicts between moving points.

Linear statistical decision models for air traffic flow simulation: a comparative study

Research on Air Traffic Flow Management (ATFM) has provided various models. Generally, these models are used for the strategic or even tactical control of flows. In this paper, we will focus on short term ATFM models. We first give an approach of macroscopic traffic flow modeling for the short term control of flights and then show how statistical decision techniques will contribute to the conception of such models. Basically, the statistical approach is used to estimate ‘dynamically’ two exogenous parameters of the traffic flow model developed in this paper: the flow orientation of an air traffic flow through a volume of controlled airspace (sector) and its travel time within the volume. Two linear discriminant analysis methods designed for categorical variables are used to estimate the decision rules of the previous outputs parameters. Comparisons of the simulation results are made through a set of 35 sectors by varying, in each case, the set of descriptor variables.