Algorithm and operational concept for resolving short-range conflicts

Abstract

Abstract:The article describes an algorithm for computing horizontal resolution trajectories with a limit on bank angle. If loss of separation can be avoided, the algorithm generates a set of manoeuvres that achieves or exceeds the specified minimum separation. The manoeuvres consist of turns to a specified heading followed by straight-line flight. Both single aircraft and cooperative manoeuvres are generated. In cooperative manoeuvres, both conflict aircraft simultaneously execute resolution manoeuvres, which expedite the resolution process compared to single aircraft manoeuvres. If loss of separation is unavoidable for a specified bank angle limit, the method chooses the manoeuvre that maximizes the minimum separation during the turns. The characteristics of the resolution trajectories have been analysed in a parameter space comprising initial positions, encounter angle, airspeed, predicted minimum separation, and bank angle. Analysis of resolutions for sets of initial conditions provided a road map for the design of an algorithm. The conceptual design of a system is described that resolves close-in conflicts automatically by uplinking resolution advisories to aircraft. Controllers have the option to assign detected conflicts to be resolved by the system. The system also has the authority to uplink resolution advisories to the aircraft without prior controller approval if time to loss of separation falls below a threshold value. The Mode S Specific Services data link is well suited for uplinking resolution advisories to the conflict aircraft. Deployment of the system could be an initial step in building the next-generation air traffic control system.

Tactical Conflict Detection in Terminal Airspace

“…Most of the research to date has focused on en route airspace. En route prototypes of TSAFE have been developed and studied with the use of en route operational error cases [6][7][8][9], and some attention on TSAFE conflict resolution has appeared [10][11][12]. TSAFE as an independent system to aid the controller for the near term has also been proposed [8][9][10][11].…”

Performance Analysis of a Horizontal Separation Assurance Algorithm for Short-Range Conflicts

“…3 Understanding the derivation for this pair-wise separation assurance algorithm is a key step in the implementation and analysis process. Throughout this paper, winds are assumed negligible, thus air speed and heading is equivalent to ground speed and heading.…”

“…Figure 2 through Figure 6 show the separation graph used to plot the maneuvers and Figure 7 is an example conflict resolution maneuver as extracted from the separation graph. A more detailed explanation of how maneuvers are extracted from the above equations has been made available by Erzberger 3 and Trapani. …”

“…Erzberger has derived a new algorithm to create a horizontal resolution plan by analyzing the turn dynamics for both aircraft. 3 A simulation is used to measure the performance of the horizontal separation assurance algorithm developed by Erzberger. 3,4 While the simulation is running, certain events are recorded, counted, and classified into various types.…”

“…3 A simulation is used to measure the performance of the horizontal separation assurance algorithm developed by Erzberger. 3,4 While the simulation is running, certain events are recorded, counted, and classified into various types. Plotting measured data, drawing individual conflicts, and re-creating the simulation as an animation are used in this study to visualize events and measure the performance of the algorithm.…”