Distributed Scheduling Architecture for Multi-Center Time-Based Metering

Abstract

The Traffic Management Advisor (TMA) is an air traffic control automation system currently in use in seven Air Route Traffic Control Centers (ARTCCs) to enable time based metering to busy airports within their airspace. However, this system is limited to operation within a single ARTCC, within about a 200 nautical mile radius of the airport, and on relatively simple streams of traffic. The need for coordinated metering within a greater (300+ nautical mile) radius of an airport, on streams of traffic with significant branching, and across ARTCC boundaries, has been identified.Early tests revealed that TMA could not simply be scaled up to handle such a problem. Instead, a loosely coupled hierarchy of schedules, in which constraints from downstream schedules are passed upstream, is required. Such an architecture reduces the reliance on distant projections of arrival times, making schedules robust to changes in sequence and to additions of aircraft (such as aircraft departing inside the system's scheduling horizon). This architecture is also scaleable, easily reconfigurable, and can be networked together. As such, it can be adapted for use in any size or configuration of airspace and with any number of airports delivering restrictions. An implementation of this distributed scheduling architecture is currently undergoing testing in the TMA-Multi Center system. This paper describes the architecture and its motivation.

Strategies for Choosing Descent Flight-Path Angles for Small Jets

“…13 The initial condition was selected at a corresponding track point. For flights following shorter arrival routes from the north and the south, the first track point in the Center was selected.…”

“…In the United States, the Traffic Management Advisor (TMA) 13,14 computes metering-fix scheduled times of arrival (STA) at the TRACON boundary in order to control throughput of en-route traffic arriving at a high-density airport. The Efficient Descent Advisor (EDA), which was developed to assist en-route controllers in achieving TMA's STAs while maintaining separation, computes clearance advisories that also enable fuel-efficient continuous descent arrivals (CDA).…”

An Efficient Combinatorial Optimization Algorithm for Optimal Scheduling of Aircraft Arrivals at Congested Airports

“…A pilot-in-loop simulation study [2] conducted on a model of air traffic at the PHL airport has shown that instead of using a single large TMA-SC system with a 400 nm radius freeze horizon it is better to use two smaller TMA-SC systems: The inner system was designed to produce STAs at the runway and at metering points on the TRACON boundary, and had a 200 nm freeze horizon. The outer system was designed to produce STAs at the runway and metering points close to the boundaries between the ARTCCs surrounding the PHL airport and its freeze horizon was 400 nm from the runway.…”

“…A time-based strategic planning tool called Traffic Management Advisor Single Center (TMA-SC) is currently used at seven Air Route Traffic Control Centers (ARTCCs) to efficiently manage the flow of incoming aircraft to the airports within those ARTCCs [2] , and expansion to all 20 centers is planned by 2007. However, TMA-SC operates within a single ARTCC, and applying similar time-based metering at tightly constrained airports in the northeast corridor of the U.S., presents new challenges due to the nature of the airspace around these airports.…”

“…To eliminate this inefficiency, in this paper, we will work within a hierarchial scheduling architecture in which scheduling points or reference points are dispersed along the aircraft routes and separate coupled schedulers schedule aircraft to these reference points. Constraints from downstream reference points are passed to the upstream schedulers in the form of Rate profiles [2] . This hierarchial architecture eliminates the reliance on long-distance ETA estimates.…”