On the Completeness of Conflict-Based Search: Temporally-Relative Duplicate Pruning
Abstract
Conflict-Based Search (CBS) algorithm for the multi-agent pathfinding (MAPF) problem is that it is incomplete for problems which have no solution; if no mitigating procedure is run in parallel, CBS will run forever when given an unsolvable problem instance. In this work, we introduce Temporally-Relative Duplicate Pruning (TRDP), a technique for duplicate detection and removal in both classic and continuous-time MAPF domains. TRDP is a simple procedure which closes the long-standing theoretic loophole of incompleteness for CBS by detecting and avoiding the expansion of duplicate states. TRDP is shown both theoretically and empirically to ensure termination without a significant impact on runtime in the majority of problem instances. In certain cases, TRDP is shown to increase performance significantly
Cite
@article{arxiv.2408.09028,
title = {On the Completeness of Conflict-Based Search: Temporally-Relative Duplicate Pruning},
author = {Thayne T Walker and Nathan R Sturtevant},
journal= {arXiv preprint arXiv:2408.09028},
year = {2024}
}
Comments
9 pages, 4 figures, 2 tables