Latency Analysis of ROS2 Multi-Node Systems

TL;DR

This paper investigates the end-to-end latency of ROS2 in distributed systems, analyzing how different DDS middlewares and default configurations impact latency, and provides insights for optimizing ROS2-based architectures.

Contribution

It provides a detailed latency analysis of ROS2 with various DDS middlewares and profiles the stack to identify bottlenecks, offering guidelines for reducing overhead.

Findings

Latency varies significantly with DDS middleware used.

ROS2 introduces up to 50% overhead compared to low-level DDS.

Profiling reveals key latency bottlenecks in ROS2 stack.

Abstract

The Robot Operating System 2 (ROS2) targets distributed real-time systems and is widely used in the robotics community. Especially in these systems, latency in data processing and communication can lead to instabilities. Though being highly configurable with respect to latency, ROS2 is often used with its default settings. In this paper, we investigate the end-to-end latency of ROS2 for distributed systems with default settings and different Data Distribution Service (DDS) middlewares. In addition, we profile the ROS2 stack and point out latency bottlenecks. Our findings indicate that end-to-end latency strongly depends on the used DDS middleware. Moreover, we show that ROS2 can lead to 50% latency overhead compared to using low-level DDS communications. Our results imply guidelines for designing distributed ROS2 architectures and indicate possibilities for reducing the ROS2 overhead.