Accuracy of Ethernet AVB time synchronization under varying temperature conditions for automotive networks

Today´s premium vehicles are equipped with a multitude of Advanced Driver Assistance Systems (ADAS) which present additional driving information or even actively influence the vehicle behavior. These are normally highly distributed real-time systems which process information from distributed sensors like cameras or radar sensors. To fulfiill the high data rates and real-time requirements of these and future systems, it is necessary to provide a suitable underlying network architecture which can handle the communication requirements. Ethernet with its high data rates and Audio Video Bridging (AVB) with its mechanisms for time synchronization as well as traffic shaping could be one solution to interconnect such systems. An essential prerequisite for this is an extensive investigation of Ethernet AVB for automotive applications. This paper concentrates on the evaluation of the accuracy, stability, and robustness of the time synchronization mechanism of AVB under varying temperature conditions and presents measurement results obtained from a test setup with climate chambers.