THE-Planner: Topological and Hierarchical Exploration Path Planner for Fast 3D Mapping of Outdoor Structures with UAVs

Abstract

In recent years, exploration methods have been extensively researched for the purpose of mapping unknown environments with autonomous robots, aiming to replace humans. However, existing exploration methods primarily focus on indoor environments, which may not be sufficient for fast and efficient mapping of outdoor environments. In this paper, we propose a novel exploration path planner, THE-Planner, which utilizes a topological and hierarchical approach to map unknown outdoor environments quickly and efficiently. THEPlanner builds a topological map with local and global graphs. It generates global graph nodes with the robot’s positions over time. At every node, it checks the visibility of points to calculate and update frontiers. With the newly calculated frontiers, a local graph is generated, and graph-based local and global path planning is used to explore the environments. The effectiveness of the proposed method is validated in the simulations by comparing with the state-of-the-art method.