Conveyor Parcel Routing with Order-Contiguous Arrivals

2026-05-13

AI Summary

This work addresses the challenge in warehouse logistics where parcels from the same order must arrive consecutively at a workstation to avoid costly downstream re-sorting. To this end, it formally introduces, for the first time, an online multi-agent pathfinding model with order continuity constraints (online MAPF-OC) and proposes the DOPP algorithm. DOPP employs a three-layer architecture: it first searches for a feasible order-level arrival sequence, then refines parcel-level priorities, and finally generates collision-free paths based on these priorities. By integrating dual-level ordering (order and parcel), priority-based path planning, and an online incremental solving strategy, DOPP efficiently computes solutions in polynomial time. Experimental results demonstrate that DOPP consistently produces high-quality, real-time schedules within strict time limits across diverse real-world warehouse conveyor networks, exhibiting strong scalability and practical applicability.

Abstract

In warehouse logistics, parcels released from the outfeed of an automated storage system must be routed through conveyor networks to workstations. Beyond collision avoidance, practical operations impose an additional requirement of order-contiguous arrivals: at each delivery point, parcels belonging to the same order must arrive as a consecutive block in the arrival sequence to reduce downstream re-sorting effort. We formalize this problem as online multi-agent path finding with order-contiguity (online MAPF-OC), where agents (i.e., parcels) appear over time and exit upon delivery. To efficiently solve online MAPF-OC, we propose Dual-Ordering Prioritized Planning (DOPP), a complete polynomial-time algorithm with a three-level structure that (i) searches order-level arrival sequences, (ii) refines agent-level priorities, and (iii) synthesizes feasible solutions via prioritized planning. Experiments on various conveyor-network layouts, including those derived from actual warehouses, demonstrate DOPP's practical scalability and ability to generate high-quality plans within tight time budgets.

Problem

• conveyor parcel routing
• order-contiguous arrivals
• online multi-agent path finding
• warehouse logistics

Innovation

• online MAPF-OC
• order-contiguous arrivals
• Dual-Ordering Prioritized Planning
• conveyor routing
• multi-agent path finding