I. Introduction
The Robot Operating System (ROS) [1] is one of the most popular robotic software development frameworks. The most significant feature of ROS is to allow individually designed and loosely run-time coupled executables, and thus enables independent development and easy distribution. However, one of the primary shortcomings in ROS is lacking of realtime capability, which limits its application in safety-critical domains [2]. To better meet the needs of broader areas, ROS 2 [3] has been released, which not only inherits the design philosophy of ROS, but adds support for real-time control to improve the timing performance of robotic systems, i.e., ROS 2 adopts DDS [4] to implement publish-subscribe paradigm, realizing rapid and distributed communication.