Lifelong Multi-Subsystem Pickup and Delivery with Buffer-Limited Handover Stations
2026-07-20 • Robotics
RoboticsArtificial IntelligenceMultiagent Systems
AI summaryⓘ
The authors study how multiple agents handle moving items when each agent works in its own area but they must pass items through shared stations with limited space. They create a method called HARR that helps agents plan routes and reserve time at these shared stations to avoid crashes and overcrowding. Their approach checks if the shared dock is free and if there's enough buffer space before accepting a plan. In simulations, their method improved efficiency and reduced wait times compared to simpler approaches. This shows careful coordination at shared points helps multi-agent systems work better together.
Multi-Agent Pickup and Delivery (MAPD)multi-subsystem systemshandover stationsbuffer managementreservation systemsrolling-horizon planningcollision avoidancethroughputbacklogonline control
Authors
Chuanlong Zang, Isabelle Barz, Anna Mannucci, Philipp Schillinger, Florian Lier, Wolfgang Hönig
Abstract
Coordinating payload transfers between subsystems is a critical challenge in lifelong Multi-Agent Pickup and Delivery (MAPD). We study systems where agents are confined to separate regions and must exchange payloads through shared handover stations. These stations, equipped with single docks and finite buffers, are inherently vulnerable to blocking and starvation. We formalize this problem as Multi-Subsystem MAPD with Buffer-limited Handover Stations (MS-MAPD-BHS). We then propose Handover-Aware Reservation and Routing (HARR), an online controller that couples per-subsystem planners. HARR uses a shared dock reservation calendar and a deterministic rolling-horizon projection of buffer occupancy to coordinate actions. A candidate route is accepted only if its dock interval is free and the resulting buffer occupancy projection remains within capacity. Under perfect execution, these checks ensure collision-free dock use and buffer-safe committed operations within the reservation horizon. In simulation, HARR achieves up to 77% higher throughput and 92% lower backlog than a fixed-dock ablation at moderate load, while also reducing planning time relative to a coupled station-aware Token Passing baseline. These results show that explicit interface coordination substantially improves stability in modular multi-subsystem transport.