HEROS: Hierarchical Exploration with Online Subregion Updating for 3D Environment Coverage

TL;DR

This paper introduces HEROS, a hierarchical exploration system that efficiently covers unknown 3D environments by online updating subregions and planning paths at multiple levels, resulting in faster exploration with less computation.

Contribution

HEROS presents a novel hierarchical exploration framework with online subregion updating and multi-level planning, improving efficiency and reducing computational load.

Findings

Outperforms state-of-the-art methods in benchmark tests.

Achieves faster exploration with lower computational resources.

Effectively characterizes dynamic unknown regions with variable resolution.

Abstract

We present an autonomous exploration system for efficient coverage of unknown environments. First, a rapid environment preprocessing method is introduced to provide environmental information for subsequent exploration planning. Then, the whole exploration space is divided into multiple subregion cells, each with varying levels of detail. The subregion cells are capable of decomposition and updating online, effectively characterizing dynamic unknown regions with variable resolution. Finally, the hierarchical planning strategy treats subregions as basic planning units and computes an efficient global coverage path. Guided by the global path, the local path that sequentially visits the viewpoint set is refined to provide an executable path for the robot. This hierarchical planning from coarse to fine steps reduces the complexity of the planning scheme while improving exploration efficiency. The proposed method is compared with state-of-art methods in benchmark environments. Our approach demonstrates superior efficiency in completing exploration while using lower computational resources.