Research On The FlexRay Bus Applied In The Communication Between ATP On-Board Host Computer And Driver Machine Interface

Automatic Train Protection system(ATP) is the core of the train control system, which has the important function of ensuring the safe operation of the train. As an important part of ATP system,the main function of ATP on-board host computer is to generate the speed monitoring curve,in order to prevent the train speeding.High amount of data between the ATP host computer and Driver Machine Interface(DMI) has a high demand of security,reliability and real-time.However, CAN bus is used as communication bus currently,which cause the latency of data transmission, the time delay of system response to low priority data and high bus load, is unable to provide adequate network bandwidth and efficient fault-tolerant.Therefore,it is necessary to carry out research on a new kind of high speed communication bus instead of CAN bus,which is used in the ATP-DMI communication system.In this thesis,design ideas of FlexRay bus used in ATP-DMI communucation system instead of CAN bus was proposed and completed based on analyses of communication bus performance.As a new kind of In-vehicle communication bus, FlexRay has advantages in high communication rate, transmission certainty, reliability and flexibility, which is able to meet the communication requirements of ATP system.This thesis adopts the idea of’overall design of FlexRay network-design of FlexRay node-feasibility verification of FlexRay bus’,the main research contents are as follows:(1) Overall design of FlexRay network.Introduce and analyze the system structure,communication requirements and interface protocol of the ATP-DMI communication system,and design the point to point topology of FlexRay network.Based on the FlexRay protocol specification, define the network protocol parameters and dispatch management.(2) Design of FlexRay node. Analyze the function definition of FlexRay node based on the function requirements of communication network,and then complete the hardware design and software design of FlexRay node.(3) Feasibility verification of FlexRay bus.Finish the process of debugging and testing FlexRay communication network, analyzing wave forms of data frames and performance parameters, contrasting crucial service performances between FlexRay bus and CAN Bus, analyzing the applicability of FlexRay bus and propose the optimal measures of FlexRay.The FlexRay communication network debugging and verification results indicate that FlexRay bus meets the communication system requirements and can be applied to the communication system between ATP host computer and DMI.