Autonomous Teamed Exploration of Subterranean Environments using Legged and Aerial Robots

TL;DR

This paper introduces a novel autonomous exploration strategy for subterranean environments using coordinated legged and aerial robots, emphasizing resilience, multi-robot cooperation, and adaptability to complex underground terrains.

Contribution

It presents a unified onboard path planner and a multi-robot coordination framework tailored for subterranean exploration with heterogeneous robots.

Findings

Successful field deployment in an underground mine demonstrating 45-minute exploration.

Effective multi-robot coordination with shared submaps and global frontier identification.

Simulation studies with three robots confirming scalability and robustness.

Abstract

This paper presents a novel strategy for autonomous teamed exploration of subterranean environments using legged and aerial robots. Tailored to the fact that subterranean settings, such as cave networks and underground mines, often involve complex, large-scale and multi-branched topologies, while wireless communication within them can be particularly challenging, this work is structured around the synergy of an onboard exploration path planner that allows for resilient long-term autonomy, and a multi-robot coordination framework. The onboard path planner is unified across legged and flying robots and enables navigation in environments with steep slopes, and diverse geometries. When a communication link is available, each robot of the team shares submaps to a centralized location where a multi-robot coordination framework identifies global frontiers of the exploration space to inform each system about where it should re-position to best continue its mission. The strategy is verified through a field deployment inside an underground mine in Switzerland using a legged and a flying robot collectively exploring for 45 min, as well as a longer simulation study with three systems.