The ring-buffer ROS2 executor: a novel approach for real-time ROS2 Space applications

ROS2 (Robot Operating System Version 2) is an open-source software framework and suite of libraries that facilitates robotics application development and multi-core processing. ROS2 is becoming the de-facto standard for autonomous robotics application and recently. On the other hand, with the support of NASA and Blue Origin, Space-ROS -a Space applications specialized implementation of ROS2- is also starting to be used for Space autonomous applications, like landers and space robotics. ROS was designed to simplified and reduce the development time and effort required to write robotics applications and ROS2 kept this focus plus the main goal of enabling real-time robotics. In the initial design of ROS2, processing performance was given low priority, and, while an effort has been made to increase processing performance, it is not uncommon to face long latency in receiving sensor data or even non-negligible data losses. The research presented here shows a ROS2 executor implemented based on a lock-free ring-buffer that can not only increase by significantly the data processing rate with respect to the built-in ROS2 executors, but also reduce the processing consumption substantially. Successful performance results of this novel ring-buffer ROS2 executor are presented here and validated in several Space computers and the de-facto real-time benchmarking standard: the Raspberry Pi4 with Real-time Linux as operating system.