Q. Dong, H. Xi, S. Zhang*, Q. Bi, T. Li, Z. Wang, X. Zhang. Fast and Communication-Efficient Multi-UAV Exploration Via Voronoi Partition on Dynamic Topological Graph. IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2024, accepted.

Abstract

        Efficient data transmission and reasonable task allocation are important to improve multi-robot exploration efficiency. However, most communication data types typically contain redundant information and thus require massive communication volume. Moreover, exploration-oriented task allocation is far from trivial and becomes even more challenging for resource-limited unmanned aerial vehicles (UAVs). In this paper, we propose a fast and communication-efficient multi-UAV exploration method for exploring large environments. We first design a multi-robot dynamic topological graph (MR-DTG) consisting of nodes representing the explored and exploring regions and edges connecting nodes. Supported by MR-DTG, our method achieves efficient communication by only transferring the necessary information required by exploration planning. To further improve the exploration efficiency, a hierarchical multi-UAV exploration method is devised using MR-DTG. Specifically, the graph Voronoi partition is used to allocate MR-DTG's nodes to the closest UAVs, considering the actual motion cost, thus achieving reasonable task allocation. To the best of our knowledge, this is the first work to address multi-UAV exploration using graph Voronoi partition. The proposed method is compared with a state-of-the-art method in simulations. The results show that our method can reduce the exploration time and communication volume by up to 40.9% and 99.4%, respectively. Finally, the effectiveness of the proposed method is validated in the real-world experiment with 6 UAVs. We will release the source code of our method to benefit the community.