Real-time Linux communications: an evaluation of the Linux communication stack for real-time robotic applications

TL;DR

This paper evaluates the Linux communication stack's real-time performance for robotic applications, demonstrating that proper configuration and CPU separation improve communication determinism on multi-core embedded devices.

Contribution

It provides an empirical analysis of Linux UDP communication performance and proposes a CPU separation method to enhance real-time determinism in robotic systems.

Findings

Linux kernel improves UDP communication determinism with proper configuration

Concurrent traffic can disrupt bounded latencies

Separating real-time application and interrupt improves performance

Abstract

As robotics systems become more distributed, the communications between different robot modules play a key role for the reliability of the overall robot control. In this paper, we present a study of the Linux communication stack meant for real-time robotic applications. We evaluate the real-time performance of UDP based communications in Linux on multi-core embedded devices as test platforms. We prove that, under an appropriate configuration, the Linux kernel greatly enhances the determinism of communications using the UDP protocol. Furthermore, we demonstrate that concurrent traffic disrupts the bounded latencies and propose a solution by separating the real-time application and the corresponding interrupt in a CPU.