Communication Scheduling for CAN bus Autonomous Underwater Vehicles

The electronic control units (ECUs) are more modular in autonomous underwater vehicles (AUVs). The controller area network (CAN) is selected as the underlying networks in AUVs, because of the modularity, safety, and availability in the fields of distributed real-time systems. CAN is based on the broadcast communication mechanism. Every message has a message identifier, which is unique within the whole network since it defines content and the priority of the message. Bus access conflicts are resolved by bit-wise arbitration of the identifiers, which makes the node with the highest priority message holds the bus access and all the other competitors automatically become receivers of the message. This paper introduces an approach of message transmission scheduling for CAN-bus AUV. The objective is to provide the real-time transmission of periodic messages and guarantee low message latency times for messages including periodic, aperiodic and sporadic messages. Finally, an example of message transmission scheduling is presented for AUV