A scheduling algorithm for CAN bus

Abstract

This thesis discusses the issues of scheduling and priority mapping in CAN bus. A new priority assignment mechanism, the Dynamic Local Priority (DLP) scheme, is proposed to solve the problem of limited number of priority levels for CAN bus. Theoretical analysis shows that DLP mechanism has performance closer to the ideal non-preemptive EDF scheduling than the schedulers implemented by other non-preemptive algorithms. In addition, an effective schedulability condition for non-preemptive EDF algorithm is proposed, which can precisely check the schedulability of any given message set. Finally, a platform-independent scheduling simulator software is developed so as to compare the performances of different scheduling algorithms for CAN bus. And the simulation result shows that both the new schedulability condition and DLP scheme are effective and have advantages over previous methods.