Research And Design Of MVB Network Model For Rail Vehicles

Since Multifunction Vehicle Bus has the advantages of strong real-time, high reliability, redundancy and fault-tolerant performance, etc, it has been widely used in the field of ordinary train, high-speed rail and EMU. Currently, researches of MVB network mainly focus on the application areas such as MVB controller, MVB network system. In theory, the main researches are on improving the real-time reliability of MVB network through different methods, and the key technology is essentially monopolized by foreign countries. Researching on the key technology of MVB network is the inevitable requirement of the development of China’s rail transit, which will have important significance for the development of MVB equipment with independent intellectual property rights.The research of MVB network model provides a basic platform for the practical application and theoretical research of MVB network, and it has important significance to research and improve the reliability and real-time of MVB network. In this paper, the main performance of the MVB network is analyzed by the research and design of MVB network model, MVB network system redundancy model and MVB network transmission medium model. The main research contents are as follows:(1)In order to construct the MVB network model with arbitrary network size and arbitrary network topology, an integrated multi function vehicle MVB network model is established, which includes model of the master node, model of the slave node and model of the MVB network channel. And the calculation model is established for the real-time performance of process data which controlled by the MAC way of master-slave polling.Moreover, the channel utilization, real-time performance of MVB networks are analyzed and tested based on the MVB network model and its model of real-time calculation is performed in OMNET++ simulation environment. The results show that the model satisfies the requirements of IEC standard, and is able to form a MVB network flexibly, as well as achieve process data and other information communication.(2)In order to improve the reliability of the MVB network system, the redundancy ring model of MVB network system is designed based on two mode hot redundancy theory,and propose a corresponding fault detection protocol FDPM. Theoretical analysis has been performed on the reliability of MVB redundant ring network. FDPM is simulated and analyzed by establishing the model of MVB ring redundancy on OMNET++ simulation platform. The results show that when the MVB redundant ring network fails, the FDPM can switch to the monitor bus since the characteristics of reliability and real-time,accordingly the reliability of the MVB network system can be improved effectively.(3)In order to solve the problem of the reducing reliability for the Multifunction Vehicle Bus network system caused by the crosstalk and attenuation characteristics of the STP, regarding MVB24′0.56mm(AWG20) as the research object, and the MVB bus network transmission medium model with crosstalk of STP and the distribution parameters of STP is established. Through the simulation analysis of the models, compare the characteristics of crosstalk and attenuation under the parameters of different signal frequencies, cable length and cable diameter etc. The final results show that the models are feasibility and providing basis for us to analyze the characteristics of STP of MVB bus network and the layout optimization of transmission medium structure of MVB network.This paper expanded research in terms of MVB media, nodes, network and application models. Based on the design of the model, the real-time performance and reliability of the network are verified. The research contents and result will provide reference to the application of practical and theoretical studies of MVB network.