Efficient Multi-Robot Exploration with Energy Constraint based on Optimal Transport Theory

TL;DR

This paper introduces an energy-aware multi-robot exploration method based on optimal transport theory, enabling efficient coverage of areas of interest with both centralized and decentralized algorithms, adaptable to heterogeneous robots and dynamic environments.

Contribution

It develops an OT-based exploration scheme that incorporates energy constraints, decouples from robot dynamics, and provides computationally efficient centralized and decentralized algorithms.

Findings

The scheme effectively covers target areas with energy constraints.

Decentralized algorithms perform comparably to centralized ones.

The method adapts to time-varying distributions.

Abstract

This paper addresses an Optimal Transport (OT)-based efficient multi-robot exploration problem, considering the energy constraints of a multi-robot system. The efficiency in this problem implies how a team of robots (agents) covers a given domain, reflecting a priority of areas of interest represented by a density distribution, rather than simply following a preset of uniform patterns. To achieve an efficient multi-robot exploration, the optimal transport theory that quantifies a distance between two density distributions is employed as a tool, which also serves as a means of performance measure. The energy constraints for the multi-robot system is then incorporated into the OT-based multi-robot exploration scheme. The proposed scheme is decoupled from robot dynamics, broadening the applicability of the multi-robot exploration plan to heterogeneous robot platforms. Not only the centralized but also decentralized algorithms are provided to cope with more realistic scenarios such as communication range limits between agents. To measure the exploration efficiency, the upper bound of the performance is developed for both the centralized and decentralized cases based on the optimal transport theory, which is computationally tractable as well as efficient. The proposed multi-robot exploration scheme is also applicable to a time-varying distribution, where the spatio-temporal evolution of the given reference distribution is desired. To validate the proposed method, multiple simulation results are provided.