A Priority-Based Distributed Channel Access Mechanism for Control over CAN-like Networks

In this work, we study the distributed channel access problem for multiple subsystems equipped with smart sensors sharing a capacity-limited communication network to perform their control tasks. We propose a fully distributed scheme to use the limited communication resources efficiently with respect to a quadratic cost which reflects the control performance. More specifically, we adopt a priority assignment scheme which consists of two layers: (i) a dynamic priority that corresponds to the time-varying criticality of transmission for each subsystem, and (ii) a pre-specified static priority which ensures that channel access is collision-free. We first demonstrate how the dynamic priorities can be manipulated to allocate the resources with respect to the chosen cost. Next, we propose a synchronization method which enables fully distribute implementation over controller area network (CAN) hardware. We validate the compatibility of our method with the mature hardware technology of CAN by hardware-in-the-loop simulations. Finally, we demonstrate the efficacy of our proposed scheme and evaluate its performance in large-scale networks via simulation.