ACHORD: Communication-Aware Multi-Robot Coordination With Intermittent Connectivity

Communication is an important capability for multi-robot exploration because (1) inter-robot communication (comms) improves coverage efficiency and (2) robot-to-base comms situational awareness. Exploring comms-restricted (e.g., subterranean) environments requires a system to tolerate anticipate intermittent connectivity, carefully consider requirements, otherwise mission-critical data may be lost. In this paper, we describe analyze ACHORD (Autonomous & Collaborative High-Bandwidth Operations with Radio Droppables), multi-layer networking solution which tightly co-designs the network architecture high-level decision-making improved comms. provides bandwidth prioritization timely reliable transfer despite connectivity. Furthermore, it exposes low-layer metrics application layer enable robots autonomously monitor, map, extend via droppable radios, as well restore connectivity improve collaborative exploration. We evaluate our respect performance in several challenging underground including DARPA SubT Finals competition environment. Our findings support use of stratification flow control bandwidth-usage.