Improving the Reaction Latency Analysis of Message Synchronization in ROS

Multi-sensor data fusion plays a crucial role in modern autonomous systems, enabling them to perceive the surroundings from multiple dimensions. However, the accuracy of fusion output can be compromised by the temporal inconsistency of input messages from different sources. ROS provides algorithms of message synchronization to mitigate this misalignment before the data fusion process. Nevertheless, this introduces additional latency in processing each message, which influences the real-time performance of ROS systems. Previous research [1] is the first to analyze and bound the reaction latency of the ApproximateTime synchronization policy in ROS, which is essential for analyzing the system-level end-to-end reaction time. However, their bound is overly pessimistic. In this paper, we propose a safe and tight reaction latency upper bound for the ApproximateTime policy. We conduct experiments to validate its accuracy and assess its improvements compared to [1].