{"type":"ScholarlyArticle","title":"Unifying Search-based and Compilation-based Approaches to Multi-agent Path Finding through Satisfiability Modulo Theories","authors":[{"name":"Pavel Surynek","slug":"pavel-surynek","given":"Pavel","family":"Surynek","affiliation":"FIT , Czech Technical University in Prague , Thákurova 9 , 160 00 Praha 6 , Czechia"}],"abstract":"We unify search-based and compilation-based approaches to multi-agent path finding (MAPF) through satisfiability modulo theories (SMT). The task in MAPF is to navigate agents in an undirected graph to given goal vertices so that they do not collide. We rephrase Conflict-Based Search (CBS), one of the state-of-the-art algorithms for optimal MAPF solving, in the terms of SMT. This idea combines SAT-based solving known from MDD-SAT, a SAT-based optimal MAPF solver, at the low-level with conflict elimination of CBS at the high-level. Where the standard CBS branches the search after a conflict, we refine the propositional model with a disjunctive constraint. Our novel algorithm called SMT-CBS hence does not branch at the high-level but incrementally extends the propositional model. We experimentally compare SMT-CBS with CBS, ICBS, and MDD-SAT.","doi":"10.24963/ijcai.2019/164","url":"https://ijcai.org/proceedings/2019/164","pdf":"https://ijcai.org/proceedings/2019/0164.pdf","markdown":"https://ijcai.org/proceedings/2019/164.md","bibtex":"https://ijcai.org/proceedings/2019/bibtex/164","volume":{"slug":"2019","title":"Proceedings of the Twenty-Eighth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2019","url":"https://ijcai.org/proceedings/2019/","year":2019,"location":"Macao","dates":"10-16 August 2019","editors":"Sarit Kraus","isbn":"978-0-9992411-4-1","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2019"},"section":"Constraints and SAT","track":"Main track","number":164,"pages":{"first":1177,"last":1183},"keywords":["Planning and Scheduling: Search in Planning and Scheduling","Robotics: Motion and Path Planning","Constraints and SAT: Constraint Satisfaction","Planning and Scheduling: Robot Planning"],"videos":[],"references":[{"position":1,"raw":"[Audemard and Simon, 2009] G. 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