Deterministic Ethernet: Addressing the Challenges of Asynchronous Sensing in Sensor Fusion Systems

In this paper, we study the cause of out-of-sequence measurements (OOSM) and their effect on Kalman filter based multi-sensor fusion systems. We explore the current available solutions for handling of OOSM and pinpoint how the absence of precise measurement timestamps does not allow the correct chronological order of sensor measurements. The processing of such, out-of-order measurements, leads to negative-time measurement updates in the sensor fusion process, which in turn leads to a wrong representation of the environment.Furthermore, we present methods for achieving precise measurement timestamps. We explore the suitability of set of communication standards for improving the timestamp precision. In particular we focus on IEEE 802.1AS, IEEE 802.1Qav, Qbv and SAE AS6802 standards that enable deterministic communication over IEEE802.3 standard Ethernet. We present theoretical performance studies and comparison of the said communication standards.