Decentralized Multi-Agent Path Finding for UAV Traffic Management

Abstract

The development of a real-world Unmanned Aircraft System (UAS) Traffic Management (UTM) system to ensure the safe integration of Unmanned Aerial Vehicles (UAVs) in low altitude airspace, has recently generated novel research challenges. A key problem is the development of Pre-Flight Conflict Detection and Resolution (CDR) methods that provide collision-free flight paths to all UAVs before their takeoff. Such problem can be represented as a Multi-Agent Path Finding (MAPF) problem. Currently, most MAPF methods assume that the UTM system is a centralized entity in charge of CDR. However, recent discussions on UTM suggest that such centralized control might not be practical or desirable. Therefore, we explore Pre-Flight CDR methods where independent UAS Service Providers (UASSPs) with their own interests, communicate with each other to resolve conflicts among their UAV operations-without centralized UTM directives. We propose a novel MAPF model that supports the decentralized resolution of conflicts, whereby different 'agents', here UASSPs, manage their UAV operations. We present two approaches: (1) a prioritization approach and (2) a simple yet practical pairwise negotiation approach where UASSPs agents determine an agreement to solve conflicts between their UAV operations. We evaluate the performance of our proposed approaches with simulation scenarios based on a consultancy study of predicted UAV traffic for delivery services in Sendai, Japan, 2030. We demonstrate that our negotiation approach improves the "fairness" between UASSPs, i.e. the distribution of costs between UASSPs in terms of total delays and rejected operations due to replanning is more balanced when compared to the prioritization approach.

Reservation-Based 3D Intersection Traffic Control System for Autonomous Unmanned Aerial Vehicles

“…The problem of UAVs' integration into the urban airspace was also addressed in papers in [6][7][8][9]. A framework consisting of a decentralized approach is implemented in [6,7].…”

“…The problem of UAVs' integration into the urban airspace was also addressed in papers in [6][7][8][9]. A framework consisting of a decentralized approach is implemented in [6,7]. In [8,9], a structure for the low-altitude airspace com of airways and nodes was proposed, where the UAVs travel along the airways and the airways are connected by the nodes.…”

6G Enabled Unmanned Aerial Vehicle Traffic Management: A Perspective

“…A previous study [12] used an enhanced genetic algorithm and A* algorithm to guarantee that the UAVs cover the shortest path from the source to the destination with fewer error corrections. However, another study [13] proposed a multi-agent path finding (MAPF) based on an enhanced conflict-based search mechanism for UTM that performs better and has more time efficiency than incremental planning based on Cooperative A*, and it can satisfy timely response on the delivery request to UTM service users. Several other studies have been conducted to improve the path planning for UAV systems [14], [15], [16], [15], [17], and [18].…”

Interface Design for Human-Machine Collaborations in Drone Management

“…The GPS coordinates are then communicated to the UAV and executed. A derivation of the mathematical details for translating the different coordinate systems is reported in [62]. A human operator could potentially take over later when the drone has reached its target destination.…”