Frame Design for Vehicular FlexRay Network Based on Transmission Reliability and Slot Utilization

FlexRay has been taken as the next generation protocol of automotive network and has been applied to the safety critical control systems in vehicle. Frame packing is one of key problems in the design of vehicular communication because it directly relates to communication reliability and network utilization. In this paper, the transmission reliability and the slot utilization are defined for FlexRay network, and their quantitative calculating formulas are deduced. To ensure reliable network transmission and maximize bandwidth utilization of network, frame packing of FlexRay is formulated as generalized integer linear programming, and an optimized model is presented. Considering the intensive computation, a heuristic frame-packing algorithm called FPBOR is proposed to optimize signal combinations and static slot allocations. The experimental results in CANoe validate the proposed method. Compared with existing frame-packing method, the proposed method has better performance in the slot utilization and the execution time.