Fast Frontier-based Information-driven Autonomous Exploration with an MAV

• Published in: arXiv.org 2020-02
• Main Authors: Dai, Anna, Papatheodorou, Sotiris, Funk, Nils, Tzoumanikas, Dimos, Leutenegger, Stefan
• Format: Article
• Language: English
• Subjects: Clustering; Collision avoidance; Computer simulation; Entropy; Exploration; Mapping; Micro air vehicles (MAV); Motion planning; Occupancy; Octrees; Travel time; Unknown environments; Utility functions
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2002.04440

Exploration and collision-free navigation through an unknown environment is a fundamental task for autonomous robots. In this paper, a novel exploration strategy for Micro Aerial Vehicles (MAVs) is presented. The goal of the exploration strategy is the reduction of map entropy regarding occupancy probabilities, which is reflected in a utility function to be maximised. We achieve fast and efficient exploration performance with tight integration between our octree-based occupancy mapping approach, frontier extraction, and motion planning-as a hybrid between frontier-based and sampling-based exploration methods. The computationally expensive frontier clustering employed in classic frontier-based exploration is avoided by exploiting the implicit grouping of frontier voxels in the underlying octree map representation. Candidate next-views are sampled from the map frontiers and are evaluated using a utility function combining map entropy and travel time, where the former is computed efficiently using sparse raycasting. These optimisations along with the targeted exploration of frontier-based methods result in a fast and computationally efficient exploration planner. The proposed method is evaluated using both simulated and real-world experiments, demonstrating clear advantages over state-of-the-art approaches.