Research And Design Of CAN/FlexRay Hybrid Network For Automotive Electronic Control System

With the continuous development of automotive electronic control systems,automotive networks have changed from a single bus to a multi-bus coexisting hybrid network.The buses currently used in automotive electronic control systems are LIN,CAN,MOST,FlexRay,and Ethernet buses.Among them,the CAN bus is the most widely used bus in modern automobiles,and the FlexRay bus is a representative bus of a car-by-wire system.Therefore,the research on the hybrid network formed by these two buses is very necessary and has theoretical and practical significance.Because it is a CAN/FlexRay hybrid network formed by CAN network nodes and FlexRay network nodes,the message interaction of a single CAN network,FlexRay network,and CAN/FlexRay mixed network must be studied separately.This paper first studies the message scheduling algorithm for CAN networks.By combining the ideas of shared clock algorithm and dynamic ID sequence algorithm,a shared ID sequence algorithm(SIDS)is proposed to enhance the real-time and stability of CAN network message transmission.Than,the message scheduling algorithm of FlexRay network is researched.Most of the optimization research of FlexRay messages is currently only on the static segment or dynamic segment.This article reduces the worst-case response time and the total load rate of dynamic segments by placing messages with longer dynamic segments into static segments,and then segmenting the static segment messages.So as to achieve the overall optimization of FlexRay network messages.Finally,the CAN/FlexRay hybrid network was designed.The CAN/FlexRay hybrid network was formed by selecting some control systems of the electric vehicle chassis,such as BMS,ABS,SBW,etc.After understanding the principles of these control systems,a communication matrix was designed and implemented using CANoe software Interaction of messages between hybrid networks.