Scalable Multi-Robot Path Planning via Quadratic Unconstrained Binary Optimization

TL;DR

This paper presents a scalable multi-robot path planning method using QUBO, which reduces complexity and enables near-optimal solutions in dense environments, demonstrating promising scalability and practical applicability.

Contribution

It introduces a robotics-oriented QUBO formulation with BFS-based pre-processing, adaptive penalties, and a time-windowed decomposition for scalable multi-robot path planning.

Findings

Achieved over 95% variable reduction with BFS pre-processing.

Demonstrated near-optimal solutions in dense grid scenarios.

Showed favorable scaling compared to classical sequential planning.

Abstract

Multi-Agent Path Finding (MAPF) remains a fundamental challenge in robotics, where classical centralized approaches exhibit exponential growth in joint-state complexity as the number of agents increases. This paper investigates Quadratic Unconstrained Binary Optimization (QUBO) as a structurally scalable alternative for simultaneous multi-robot path planning. This approach is a robotics-oriented QUBO formulation incorporating BFS-based logical pre-processing (achieving over 95% variable reduction), adaptive penalty design for collision and constraint enforcement, and a time-windowed decomposition strategy that enables execution within current hardware limitations. An experimental evaluation in grid environments with up to four robots demonstrated near-optimal solutions in dense scenarios and favorable scaling behavior compared to sequential classical planning. These results establish a practical and reproducible baseline for future quantum and quantum-inspired multi-robot coordinations.