Priority-Based Conflict Resolution for Manned and Unmanned Aircraft Integrated Operations

Abstract

Integration of Unmanned Aircraft Systems into the airspace is one of the major challenges in global air traffic management. Unlike previous conflict resolution methods intended solely for a specific type of aircraft, either manned or unmanned, this paper develops a priority-based approach for manned and unmanned aircraft resolution coordination in nonsegregated airspace. The motivation is to maximize the resolution efficiency profit of a priority ranking mechanism, where the most conflict-influential aircraft are handled first with aircraft heterogeneity considered. To support such mechanism, complex relations among multiple aircraft need to be analyzed for the determination of the deconflicting aircraft and the corresponding resolution order. First, aircraft priorities are allocated by an extended PageRank algorithm, where influential aircraft assume larger values and more maneuver responsibilities for deconfliction. The influence of aircraft is determined by its heterogeneous attributes (e.g., vehicle type, onboard system capability, mission category, health state) and its conflict severity in the overall conflict scenario. Next, feasible resolution strategies, including speed and heading maneuver options, are illustrated in the solution space diagram according to aircraft priority order. For final maneuver decision-making, the satisficing game theory is applied to ensure maneuver optimality both in terms of safety (e.g., conflict risk) and efficiency (e.g., adjustment cost). Specifically, effects of maneuver delay and secondary conflict are also incorporated to ensure maneuver utility. Simulation results verify the improved approach capability under various integrated operation scenarios. As a result, an efficient resolution is achieved with minimal aircraft maneuvers and deviations.