A Quantum Computing Approach for Multi-robot Coverage Path Planning
Poojith U Rao, Florian Speelman, Balwinder Sodhi, Sachin Kinge
TL;DR
The paper addresses multi-robot Coverage Path Planning, an NP-hard problem, by encoding path search on a 2D grid into a Quantum Approximate Optimization Algorithm (QAOA) framework. It introduces a binary decision variable and a multi-term objective that jointly accounts for obstacle avoidance, coverage, and path overlap, and designs a hierarchy of mixers (including Simultaneous Bit Flip and four-node controlled mixers) and a phase separator to confine search to feasible solutions. A proof of explorability shows that Simultaneous Bit Flip operations on four-node sub-grids can transform any feasible path into any other, enabling thorough exploration. Resource estimates detail qubit counts and gate requirements, and experiments compare QAOA, Simulated Annealing, and DFS on small grids, validating the approach for a single robot and illustrating SA performance for larger multi-robot cases. The work lays groundwork for quantum CPP via QAOA and suggests future QUBO formulations and annealer comparisons, potentially informing real-world multi-robot path planning.
Abstract
This paper tackles the multi-vehicle Coverage Path Planning (CPP) problem, crucial for applications like search and rescue or environmental monitoring. Due to its NP-hard nature, finding optimal solutions becomes infeasible with larger problem sizes. This motivates the development of heuristic approaches that enhance efficiency even marginally. We propose a novel approach for exploring paths in a 2D grid, specifically designed for easy integration with the Quantum Alternating Operator Ansatz (QAOA), a powerful quantum heuristic. Our contribution includes: 1) An objective function tailored to solve the multi-vehicle CPP using QAOA. 2) Theoretical proofs guaranteeing the validity of the proposed approach. 3) Efficient construction of QAOA operators for practical implementation. 4) Resource estimation to assess the feasibility of QAOA execution. 5) Performance comparison against established algorithms like the Depth First Search. This work paves the way for leveraging quantum computing in optimizing multi-vehicle path planning, potentially leading to real-world advancements in various applications.
