Protocol-Based Congestion Management for Advanced Air Mobility

Abstract

Advanced air mobility operations are expected to significantly increase the demand for limited airspace resources. Two key features distinguish advanced air mobility operations from commercial aviation. First, unlike commercial aviation, where flight schedules are set months in advance, advanced air mobility demand is dynamic (i.e., flights are planned with a much shorter lead-time). Thus, operators benefit from planning in shorter time horizons and can confidently share their desired flight trajectories only for the near future. In addition, operators may be unwilling to share estimates of the full trajectory, for competitive reasons. The second key feature is the large-scale of operations. Thus, a centralized optimization approach may not scale to meet the expected levels of demand, and it offers no redundancy against communication failures. In this paper, we address these challenges by designing a protocol that determines the “rules-of-the-road” for airspace access. Our protocol centers on the construction of priority queues to determine access to each congested volume of airspace. We leverage the concepts of backpressure (measure of queue buildup) and cycle detection (vehicles that block each other from proceeding) to promote efficiency, and present several flight- and operator-level prioritization schemes. In the absence of actual demand data, we study three scenarios: random origin–destination missions, crossflow traffic patterns, and simulated hub-based package delivery operations. We evaluate our protocols on two performance measures: efficiency (i.e., magnitudes of delays) and fairness (i.e., equitable distribution of delay across flights and operators).