Starvation-avoidance CAN Scheduling for Shorter Worst-case Response Time with Priority Queues

Abstract

Controller Area Network is a message based event-triggered communication service, and primarily applied in automotive and various industries such as vehicles, multi-robot, realtime communication systems and others. On vehicle networks, the CAN bus connects multiple independent Electronic Control Units (ECU) and allows them to communicate and work together asynchronously and/or synchronously. The ECU nodes exchange data with the CAN bus concurrently so that multiple messages collide on the bus, which is resolved by a bitwise arbitration algorithm that works by assigning a low-priority node to switch to listening mode while a node with high-priority message remains in transmitting mode. However, this arbitration mechanism results in starvation of low-priority messages. In this paper, we present a real-time scheduling algorithm that provides starvation avoidance over CAN messages.