Resumen de Cost-based linear holding practice and collaborative air traffic flow management under trajectory based operations
The current air transportation system is reaching the capacity limit in many countries/regions across the world. It tends to be less efficient or even incapable sometimes to deal with the enormous air traffic demand that continues growing year by year. This has been evidenced by the record-breaking flight delays reported in various places in recent years, which, have resulted in notable economical loses. To mitigate this imbalance between demand and capacity, air traffic flow management (ATFM) is usually one of the most useful options. It regulates traffic flows according to air traffic control capacity while preserving safety and efficiency of flights.
ATFM initiatives can be considered well in advance of the flight execution - more than one year earlier - based on air traffic forecasts and capacity plans, and continue in effect, with information updated, to eventually the day of operation. This long effective period will inevitably allow substantial collaboration among different stakeholders, including the ATFM authority, airspace users (AUs), air navigation service providers (ANSPs), airports, etc. Under the forthcoming paradigm of trajectory based operations (TBO), the flight 4-Dimensional trajectory has been anticipated to further enhance the connection between flight planning and execution phases, thus fostering such collaboration in ATFM.
Moreover, under nowadays operations, ground holding is a typical measure undertaken in many widely-used ATFM programs. Even though holding on the ground, at the origin airport, has the advantage of fuel efficiency over the air holding, it turns out that its feature of low flexibility would, in some circumstances, affect the ATFM performance. Yet, with proper flight trajectory management, it is also possible to have delay airborne at no extra fuel cost than performing ground holding.
This PhD thesis firstly focuses on this trajectory management, specifically on a cost-based linear holding practice. The linear holding is realized progressively along the planned trajectory through precise speed control which can be enabled by aircraft trajectory optimization techniques. Some typical short/mid haul flights are simulated for achieving the maximum airborne delay that can be yielded using same fuel consumption as initially scheduled. Based on this, its potential applicability is demonstrated.
A network ATFM model is adapted from the well-studied Bertsimas Stock-Patterson (BSP) model, incorporating different types of delay (including the linear holding) to flexibly handle the traffic flow with a set of given (yet changeable) capacities. In order that the benefits of the model can be fully realized, AUs are required to participate in the decision-making process, submitting for instance the maximum linear holding bound per flight along the planned trajectory.
Next, increased AUs' participation is expected for a proposed Collaborative ATFM framework, in which not only various delay initiatives are considered, but also alternative trajectories which allow flights to route out of the identified hotspot areas. A centralized linear programming optimization model then computes for the best trajectory selections and the optimal delay distributions across all concerned flights.
Finally, ANSPs' involvement is additionally considered for the framework, through dynamic airspace reconfiguration, further enhancing the collaboration between ATFM stakeholders. As such, the traffic flow regulation and sector opening scheduling are bounded into an integrated optimization model, and thus are conducted in a synchronized way. Results indicate that the performance of demand and capacity balancing can be even improved if compared with the previous ATFM models presented in this PhD thesis.
