Research Of Real-time Scheduling And Network Management On FlexRay Bus System

With the development of automobile technology, the number of the electronic control units in automobile is growing and automotive electronic becomes the development trend of automobile technology. As a new generation of automobile internal network communication protocol, FlexRay bus has the features of high bandwidth, certainty and reliability, and can meet the communication needs of the advanced automobile high speed control in the future. This subject is supported by national electronic information industry develops fund. A large number of domestic and foreign literatures and research data are searched and collected, and the communication mechanisms and network management requirements of FlexRay bus are analyzed in detail to achieve the purpose of increasing bus system performance.First, this thesis introduces the background of automotive FlexRay bus system and analyzes the domestic and foreign research situations. To solve the problem of FlexRay static segment scheduling unable to cope with the dynamic change of the system, a static segment scheduling method based on dynamic allocation is presented. Scheduling node is introduced into FlexRay bus system to implement round-robin scheduling based on communication cycle by transferring trigger message (TM). The building method of period scheduling table (PST) of static messages is introduced and the content of PST is updated dynamically. To guarantee the reliability and safety of FlexRay bus system, a method of OSEK network management realized in FlexRay dynamic segment is proposed. Then the structure of the network management protocol data unit mapping to the FlexRay data frame and network management status are designed. The concrete realization process of network management is gived and the transmission delay of network management massage is analyzed.Finally, the simulation experimental platform is built by using CANoe and DaVinci Network Designer. According to the system requirement, the FlexRay bus system simulation model and communication program are designed. Then the feasibility and effectiveness of the proposed scheduling method and network management method are verified.