A well-structured and reliable communication system is key to the successful operations of multi-robot systems. In this letter, we present our design and implementation of a multi-robot communication architecture CHORD (Collaborative High-bandwidth Operations with Radio Droppables) based on two popular robotics middleware, ROS 1 and ROS 2. We discuss the benefit and best practices of combining two different frameworks that share the same spirit and show its performance from large-scale real-world experiments. The proposed system is developed as part of Team CoSTAR's effort for the DARPA Subterranean (SubT) Challenge. The system has been field-proved and demonstrated in the Urban Circuit event, where team CoSTAR won first place. To our knowledge, this work is the first real-world demonstration of a ROS 2-based multi-robot system in such large-scale extreme environments. From the significant improvement of the communication performance and the ease of transition from existing ROS 1 systems, this work encourages wider adoption of ROS 2 in field robotics applications.

中文翻译：

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CHORD：通过混合ROS 1和2进行分布式数据共享，用于大型机器人复杂环境的多机器人探索

结构良好且可靠的通信系统是多机器人系统成功运行的关键。在这封信中，我们介绍了基于两种流行的机器人中间件ROS 1和ROS 2的多机器人通信体系结构CHORD（带有无线电可丢弃性的协作式高带宽操作）的设计和实现。我们讨论了结合使用的好处和最佳实践两个具有相同精神并通过大规模实际实验展示其性能的不同框架。拟议的系统是CoSTAR团队为DARPA地下（SubT）挑战所做的努力的一部分。该系统已在“城市巡回赛”现场进行了现场验证和演示，CoSTAR团队获得了冠军。据我们所知，这项工作是在如此大规模的极端环境中基于ROS 2的多机器人系统的首次真实演示。由于通信性能的显着提高以及从现有ROS 1系统的过渡的简便性，这项工作鼓励在现场机器人应用中广泛采用ROS 2。