Enabling Large-scale Heterogeneous Collaboration with Opportunistic Communications

TL;DR

This paper introduces MOCHA, a resilient multi-robot collaboration framework utilizing opportunistic gossip communication to enable large-scale exploration without continuous connectivity, demonstrated through real-world experiments and integrated with autonomous planning.

Contribution

The paper presents MOCHA, a novel gossip-based communication framework that supports large-scale, infrastructure-free multi-robot collaboration with proven real-world and simulated performance.

Findings

MOCHA enables effective large-scale exploration with unreliable links.

The framework scales well with increasing robot numbers and varying communication ranges.

Integration with autonomous planning improves information sharing in collaborative tasks.

Abstract

Multi-robot collaboration in large-scale environments with limited-sized teams and without external infrastructure is challenging, since the software framework required to support complex tasks must be robust to unreliable and intermittent communication links. In this work, we present MOCHA (Multi-robot Opportunistic Communication for Heterogeneous Collaboration), a framework for resilient multi-robot collaboration that enables large-scale exploration in the absence of continuous communications. MOCHA is based on a gossip communication protocol that allows robots to interact opportunistically whenever communication links are available, propagating information on a peer-to-peer basis. We demonstrate the performance of MOCHA through real-world experiments with commercial-off-the-shelf (COTS) communication hardware. We further explore the system's scalability in simulation, evaluating the performance of our approach as the number of robots increases and communication ranges vary. Finally, we demonstrate how MOCHA can be tightly integrated with the planning stack of autonomous robots. We show a communication-aware planning algorithm for a high-altitude aerial robot executing a collaborative task while maximizing the amount of information shared with ground robots. The source code for MOCHA and the high-altitude UAV planning system is available open source: http://github.com/KumarRobotics/MOCHA, http://github.com/KumarRobotics/air_router.