Explanation Generation for Multi-Modal Multi-Agent Path Finding with Optimal Resource Utilization using Answer Set Programming

• Published in: Theory and practice of logic programming Vol. 20; no. 6; pp. 974 - 989
• Main Authors: BOGATARKAN, AYSU, ERDEM, ESRA
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.11.2020
• Subjects: Combinatorial analysis; Declarative programming; Flexibility; Mathematical programming; Multiagent systems; Optimization; Original Article; Resource utilization; Warehouses
• ISSN: 1471-0684; 1475-3081
• DOI: 10.1017/S1471068420000320

The multi-agent path finding (MAPF) problem is a combinatorial search problem that aims at finding paths for multiple agents (e.g., robots) in an environment (e.g., an autonomous warehouse) such that no two agents collide with each other, and subject to some constraints on the lengths of paths. We consider a general version of MAPF, called mMAPF, that involves multi-modal transportation modes (e.g., due to velocity constraints) and consumption of different types of resources (e.g., batteries). The real-world applications of mMAPF require flexibility (e.g., solving variations of mMAPF) as well as explainability. Our earlier studies on mMAPF have focused on the former challenge of flexibility. In this study, we focus on the latter challenge of explainability, and introduce a method for generating explanations for queries regarding the feasibility and optimality of solutions, the nonexistence of solutions, and the observations about solutions. Our method is based on answer set programming.