Offset Assignment on Controller Area Network: Improved Algorithms and Computational Evaluation

Abstract

The basic requirement for the design of the Controller Area Network (CAN) for in-vehicle communication is to guarantee that the worst-case response time (WCRT) of each message is smaller than their specified deadline. In addition, it is desired to achieve small WCRTs that leave sufficient slack to the message deadline. In order to address the specified objectives, the idea of offset scheduling has been introduced. In this setting, messages on CAN are released with offsets in order to avoid message bursts that lead to undesirably large response times. In order to use offset scheduling efficiently, it is required to assign a suitable offset to each message. To this end, a load distribution (LD) algorithm is proposed in the existing literature. The main contribution of this paper is the development of new algorithms for offset assignment on CAN. Evaluating different example scenarios, the paper shows that the proposed algorithms outperform the existing LD algorithm in most of the cases.