Efficient Message Scheduling for FlexRay Dynamic Segments

To address the insufficient bandwidth and message response delays in FlexRay dynamic segments within automotive communication networks, this study proposes an optimized message scheduling strategy based on the FlexRay dynamic segment (DSMSS). By holistically integrating multi-dimensional parameters—including message length, deadline, remaining processing time, and Automotive Safety Integrity Level (ASIL)—the strategy introduces a dynamic frame ID priority allocation mechanism. Leveraging dynamic programming, this approach systematically optimizes message transmission sequences. Furthermore, a new compensation scheduling method is proposed to prevent the continuous delay of low-priority messages and achieve priority transmission within the compensation period after high-priority tasks. Guided by ISO 26262 standards, electronic control units (ECUs) are classified, and an experimental platform simulating an automotive chassis control system is established using the FlexRay bus topology. The verification is performed using the CANoe.FlexRay simulation tool and the VN8970 hardware interface. The experimental results demonstrate that, compared to the conventional Earliest Deadline First (EDF) algorithm, the DSMSS strategy achieves a 28.1% improvement in bandwidth utilization and a 9.4% reduction in worst-case response time when transmitting 20 dynamic messages. This study addresses communication system asymmetry through balanced supply–demand scheduling, significantly enhancing real-time FlexRay performance and resource efficiency. The findings provide theoretical and technical foundations for designing efficient, robust communication architectures in intelligent connected vehicles, advancing practical solutions for bandwidth-constrained automotive networks.