Automatic Latency Management for ROS 2: Benefits, Challenges, and Open Problems
Automatic Latency Management for ROS 2: Benefits, Challenges, and Open Problems
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ROS 2 的自动延迟管理：优点、挑战和未解决的问题
DOI：
10.1109/rtas52030.2021.00029
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Björn B. Brandenburg
中科院分区：
文献类型：
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作者：
Tobias Blass;A. Hamann;R. Lange;D. Ziegenbein;Björn B. Brandenburg
机器人系统通常受到实时约束。尽管如此，ROS生态系统-最流行的开源机器人软件库-几乎没有证据表明使用实时理论来约束或控制最坏情况下的响应时间。采用的障碍是正确使用实时调度机制所需的专业知识量以及典型机器人工作负载的固有不可预测性，这些工作负载不符合静态配置。为了克服这些障碍，ROS-Llama，一个自动延迟管理器的ROS 2，提出。至关重要的是，使用ROS-Llama只需要很少的努力和实时概念的知识。ROS 2的相关属性和机器人领域的基本要求，并在开发这样一个主要是自动化的工具的概念和实际的挑战进行了讨论。在移动的机器人上的实验证明了该方法的可行性，并表明与默认的Linux调度器相比，ROS-Llama减少了负载下的最大观察延迟。最后，在底层的实时分析和主要的平台限制，在Linux和ROS 2，防止进一步的改进中的开放的问题被确定。
Robotic systems are typically subject to real-time constraints. Still, the ROS ecosystem—the most popular repository of open-source robotics software—exhibits little evidence of the use of real-time theory to bound or control worst-case response times. Hurdles to adoption are the amount of expertise required to correctly use real-time scheduling mechanisms and the inherent unpredictability of typical robotics workloads, which defy static provisioning. To overcome these hurdles, ROS-Llama, an automatic latency manager for ROS2, is proposed. Crucially, use of ROS-Llama requires only little effort and knowledge of realtime concepts. Relevant properties of ROS2 and essential requirements of the robotics domain are identified, and the conceptual and practical challenges in developing such a mostly automatic tool are discussed. Experiments on a mobile robot demonstrate the viability of the approach and show that ROS-Llama reduces the maximum observed latency under load compared to the default Linux scheduler. Finally, open problems in the underlying real-time analysis and major platform limitations in Linux and ROS2 that prevent further improvements are identified.