Research And Realization Of Real-time Scheduling Method On FlexRay Bus System

With the development of automobile electronic technology, the demands of users make the Auto function constantly powerful. Different kinds of car electronic control units lead to the system structure more and more complex. In order to reduce the number of car wiring harness and simplify the internal structure, car bus technology was presented. FlexRay bus as a new generation of car bus has higher data transmission rata than a CAN bus and more diverse data transmission way, a variety of topology selection and the advantages of more precise fault tolerant operation. It will be the mainstream of future automotive network standard.From the perspective of real-time scheduling, this dissertation discussing FlexRay bus system of static and dynamic scheduling problem is aimed at improving bus system performance. Introduce the research status and basic characteristics of FlexRay standard and analyze the frame format and coding principle; in view of the FlexRay static scheduling can not meet the dynamic change of system, put forward a kind of static scheduling method based on period scheduling table and realize the flexible scheduling in static period by introducing the scheduling node sending trigger message; for aperiodic messages on dynamic segment, in order to improve the real-time performance of the system, adopt a reasonable and effective allocation FID method of dynamic messages, make all dynamic messages’ worst-case response time minimum. The method is evaluated in the CANoe and DaVinci Network Designer and validates the feasibility and effectiveness of optimization method.The research of this topic in guaranteeing the transmission of FlexRay periodic messages and aperiodic messages before deadline improves the real-time performance of FlexRay bus system and enhances the flexibility of the system.