Title: Controller area network with priority queues and FIFO queues: improved schedulability analysis and message set extension
Authors: Klaus Werner Schmidt; Burak Alkan; Ece Güran Schmidt; Duygu Çulum Karani; Utku Karakaya
Addresses: Department of Mechatronics Engineering, Çankaya University, Ankara 06790, Turkey ' Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara 06800, Turkey ' Department of Electrical and Electronics Engineering, Middle East Technical University, Ankara 06800, Turkey ' TOFAŞ Türk Otomobil Fabrikası A.Ş., Bursa 16369, Turkey ' TOFAŞ Türk Otomobil Fabrikası A.Ş., Bursa 16369, Turkey
Abstract: Controller area network (CAN) enables communication of electronic control units (ECUs) via messages using priority-based arbitration, which requires the implementation of priority queues (PQs) in the ECU device driver. Nevertheless, it is possible that not all ECUs on a CAN support PQs but use FIFO queues (FQs) instead. In this case, the classical CAN scheduling model with PQs is not suitable for the computation of message worst-case response times (WCRTs) that are essential for verifying the correct vehicle operation. This paper considers an existing scheduling model for CAN with both PQs and FQs. First, an improved algorithm for speeding up the WCRT computation is proposed. Second, the practical case where an existing CAN message set is extended by new messages is addressed. An original algorithm for assigning priorities to new messages while keeping the priority order of existing messages is developed. Both algorithms are evaluated by computational experiments.
Keywords: CAN; controller area networks; priority queues; FIFO queues; schedulability; priority assignment; message set extension; priority queues; scheduling; electronic control units; ECUs; vehicle communications.
International Journal of Vehicle Design, 2016 Vol.71 No.1/2/3/4, pp.335 - 357
Received: 08 Nov 2014
Accepted: 28 Nov 2015
Published online: 02 Sep 2016 *