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 improves situational awareness. Exploring comms-restricted (e.g., subterranean) environments requires a multi-robot 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 High-Bandwidth 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.

[1]  J. Edlund,et al.  PropEM-L: Radio Propagation Environment Modeling and Learning for Communication-Aware Multi-Robot Exploration , 2022, Robotics: Science and Systems XVIII.

[2]  Roland Siegwart,et al.  CERBERUS: Autonomous Legged and Aerial Robotic Exploration in the Tunnel and Urban Circuits of the DARPA Subterranean Challenge , 2022, Field Robotics.

[3]  Eric W. Frew,et al.  Multi-Agent Autonomy: Advancements and Challenges in Subterranean Exploration , 2021, Field Robotics.

[4]  Jeffrey A. Edlund,et al.  CHORD: Distributed Data-Sharing via Hybrid ROS 1 and 2 for Multi-Robot Exploration of Large-Scale Complex Environments , 2021, IEEE Robotics and Automation Letters.

[5]  Katrina Lo Surdo,et al.  Heterogeneous Ground and Air Platforms, Homogeneous Sensing: Team CSIRO Data61's Approach to the DARPA Subterranean Challenge , 2021, Field Robotics.

[6]  Bhaskar Krishnamachari,et al.  A Queue-Stabilizing Framework for Networked Multi-Robot Exploration , 2021, IEEE Robotics and Automation Letters.

[7]  Jay L. Gao,et al.  NeBula: Quest for Robotic Autonomy in Challenging Environments; TEAM CoSTAR at the DARPA Subterranean Challenge , 2021, ArXiv.

[8]  David D. Fan,et al.  STEP: Stochastic Traversability Evaluation and Planning for Safe Off-road Navigation , 2021, Robotics: Science and Systems.

[9]  Amanda Bouman,et al.  PLGRIM: Hierarchical Value Learning for Large-scale Exploration in Unknown Environments , 2021, ICAPS.

[10]  Dimos V. Dimarogonas,et al.  Intermittent Connectivity Maintenance With Heterogeneous Robots , 2021, IEEE Transactions on Robotics.

[11]  Benjamin Morrell,et al.  Range-Aided Pose-Graph-Based SLAM: Applications of Deployable Ranging Beacons for Unknown Environment Exploration , 2021, IEEE Robotics and Automation Letters.

[12]  M. A. Hsieh,et al.  Asynchronous Adaptive Sampling and Reduced-Order Modeling of Dynamic Processes by Robot Teams via Intermittently Connected Networks , 2020, 2020 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[13]  Jeffrey A. Edlund,et al.  Supervised Autonomy for Communication-degraded Subterranean Exploration by a Robot Team , 2020, 2020 IEEE Aerospace Conference.

[14]  Alois Knoll,et al.  OPC UA versus ROS, DDS, and MQTT: Performance Evaluation of Industry 4.0 Protocols , 2019, 2019 IEEE International Conference on Industrial Technology (ICIT).

[15]  Michael Wolf,et al.  Review of Multi-Agent Algorithms for Collective Behavior: a Structural Taxonomy , 2018, ArXiv.

[16]  Nicola Basilico,et al.  Multirobot Exploration of Communication-Restricted Environments: A Survey , 2017, IEEE Intelligent Systems.

[17]  Michael M. Zavlanos,et al.  Multirobot Data Gathering Under Buffer Constraints and Intermittent Communication , 2017, IEEE Transactions on Robotics.

[18]  Michael M. Zavlanos,et al.  Temporal Logic Task Planning and Intermittent Connectivity Control of Mobile Robot Networks , 2017, IEEE Transactions on Automatic Control.

[19]  Andrea Gasparri,et al.  Throughput-Optimal Robotic Message Ferrying for Wireless Networks Using Backpressure Control , 2014, 2014 IEEE 11th International Conference on Mobile Ad Hoc and Sensor Systems.

[20]  Stephen Cameron,et al.  Time Preference for Information in Multi-agent Exploration with Limited Communication , 2013, TAROS.

[21]  Ning Xi,et al.  Connectivity and bandwidth-aware real-time exploration in mobile robot networks , 2013, Wirel. Commun. Mob. Comput..

[22]  Antonio Franchi,et al.  A passivity-based decentralized strategy for generalized connectivity maintenance , 2013, Int. J. Robotics Res..

[23]  Yasamin Mostofi,et al.  Robotic Router Formation in Realistic Communication Environments , 2012, IEEE Transactions on Robotics.

[24]  Mehrzad Malmirchegini,et al.  Estimation of communication signal strength in robotic networks , 2010, 2010 IEEE International Conference on Robotics and Automation.

[25]  Wei Yang,et al.  Robotic Routers: Algorithms and Implementation , 2009, Int. J. Robotics Res..

[26]  Vijay Kumar,et al.  Connectivity management in mobile robot teams , 2008, 2008 IEEE International Conference on Robotics and Automation.

[27]  Eric W. Frew,et al.  Maintaining Optimal Communication Chains in Robotic Sensor Networks using Mobility Control , 2007, Mob. Networks Appl..

[28]  Andreas Birk,et al.  Multi-robot exploration under the constraints of wireless networking , 2007 .

[29]  Joydeep Biswas,et al.  Robofleet: Secure Open Source Communication and Management for Fleets of Autonomous Robots , 2021, ArXiv.

[30]  R. Murray,et al.  Planning and Optimization for Multi-Robot Planetary Cave Exploration under Intermittent Connectivity Constraints , 2020 .

[31]  Maíra Saboia da Silva,et al.  TRAVERSABILITY-AWARE SIGNAL COVERAGE PLANNING FOR COMMUNICATION NODE DEPLOYMENT IN PLANETARY CAVE EXPLORATION , 2020 .

[32]  Mohammad Reza Nami,et al.  Multi-Agent Systems: A Survey , 2010, PDPTA.