Project Info

Location: NASA Jet Propulsion Laboratory, Caltech; Pasadena, California

Project Members: Maira Saboia, Lillian Clark, Vivek Thangavelu, Jeffrey A Edlund, Kyohei Otsu, Gustavo J Correa, Vivek Shankar Varadharajan, Angel Santamaria-Navarro, Thomas Touma, Amanda Bouman, Hovhannes Melikyan, Torkom Pailevanian, Sung-Kyun Kim, Avak Archanian, Tiago Stegun Vaquero, Giovanni Beltrame, Nils Napp, Gustavo Pessin, Ali-akbar Agha-mohammadi

Citation: M. Saboia, L. Clark, V. Thangavelu, J. A. Edlund, K. Otsu, G. J. Correa, V. S. Varadharajan, ... and A. Agha-mohammadi. ACHORD: Communication-Aware Multi-Robot Coordination with Intermittent Connectivity." IEEE Robotics and Automation Letters (RA-L) and IEEE Int. Conf. on Intelligent Robots and Systems (IROS), 2022. (https://arxiv.org/pdf/2206.02245)

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

Gallery

The image on the left illustrates ACHORD and the communication pipeline starting from the physical layer consisting of droppable radios that are used to form a mesh network to the highest layer which include autonomy behaviors and connectivity monitoring. The image on the right depicts the Information RoadMap (IRM) which indicates the areas of the environment with strong, weak and no comms. Images are from [@saboia2022achord].

References

[@saboia2022achord] M. Saboia, L. Clark, V. Thangavelu, J. A. Edlund, K. Otsu, G. J. Correa, V. S. Varadharajan, ... and A. Agha-mohammadi. ACHORD: Communication-Aware Multi-Robot Coordination with Intermittent Connectivity." IEEE Robotics and Automation Letters (RA-L) and IEEE Int. Conf. on Intelligent Robots and Systems (IROS), 2022. (https://arxiv.org/pdf/2206.02245)