Real-Time LaCAM for Real-Time MAPF

Runzhe Liang*, Rishi Veerapaneni*, Daniel Harabor, Jiaoyang Li, Maxim Likhachev.

Symposium on Combinatorial Search (SoCS), pages 196-200, 2025.

Publisher arXiv

The vast majority of Multi-Agent Path Finding (MAPF) methods with completeness guarantees require planning full-horizon paths. However, planning full-horizon paths can take too long and be impractical in real-world applications. Instead, real-time planning and execution, which only allows the planner a finite amount of time before executing and replanning, is more practical for real-world multi-agent systems. Several methods utilize real-time planning schemes but none are provably complete, which leads to livelock or deadlock. Our main contribution is Real-Time LaCAM, the first Real-Time MAPF method with provable completeness guarantees. We do this by leveraging LaCAM in an incremental fashion. Our results show how we can iteratively plan for congested environments with a cutoff time of milliseconds while still maintaining the same success rate as full-horizon LaCAM. We also show how it can be used with a single-step learned MAPF policy.

@inproceedings{ LiangSoCS25,
  author    = "Runzhe Liang and Rishi Veerapaneni and Daniel Harabor and Jiaoyang Li and Maxim Likhachev",
  title     = "Real-Time LaCAM for Real-Time MAPF",
  booktitle = "Proceedings of the Symposium on Combinatorial Search (SoCS)",
  pages     = "196-200",
  year      = "2025",
  doi       = "10.1609/socs.v18i1.35993",
}

Abstract:

The vast majority of Multi-Agent Path Finding (MAPF) methods with completeness guarantees require planning full-horizon paths. However, planning full-horizon paths can take too long and be impractical in real-world applications. Instead, real-time planning and execution, which only allows the planner a finite amount of time before executing and replanning, is more practical for real-world multi-agent systems. Several methods utilize real-time planning schemes but none are provably complete, which leads to livelock or deadlock. Our main contribution is Real-Time LaCAM, the first Real-Time MAPF method with provable completeness guarantees. We do this by leveraging LaCAM in an incremental fashion. Our results show how we can iteratively plan for congested environments with a cutoff time of milliseconds while still maintaining the same success rate as full-horizon LaCAM. We also show how it can be used with a single-step learned MAPF policy.