Research On Virtual Link Layer Scheduling Algorithm Of Time Triggered AFDX End System

With the development of integrated modular avionics system, expandingaviation communication system task, traditional data bus cannot meet therequirements of high speed and reliable data transmission. At present advanced databus Avionics Full duplex Switched Ethernet has made great improvements in manyaspects such as bandwidth, bus structure, data transmission mechanism and so on.But there are still some aspects to be improved in guarantee deterministic messagetransmission. End system is an important part of AFDX network, and its protocolstack various stratified joint can realize the function of data transmission. To meetthe needs of avionics communication system with high reliability, real-time andstrictly deterministic, the main research content of this article is to optimizescheduling algorithm to improve the network performance in AFDX end systemvirtual link layer.Firstly, introduce the research background and significance. Discuss the currentsituation of the development of aviation data bus and argument the superiority ofAFDX by comparing with several typical data bus such as MIL-STD-1553B,ARINC429and ARINC629. Analys is scheduling algorithm used by AFDX endsystem at present and time triggered communication protocol, this paper uses thetime triggered mechanism to improve the communication determin istic performanceof AFDX network.Secondly, consideration the demand of avionics communication, design timetriggered scheduling algorithm of AFDX end system virtual link layer combiningwith the time triggered communication mechanism. Construct AFDX network modeland analyze process of time triggered scheduling algorithm. Compare withcommonly used scheduling policy in theoretical calculation and simulationexperiment, to show the superior performance of time triggered scheduling policy inAFDX network.Thirdly, analysing the protocol stack of AFDX end system and the function ofthe virtual link layer, the general structure of the virtual link layer is put forward.The key is to design transmitter and receive part of the modular in detail. Realize thefunction of the end system virtual link layer based on FPGA, and complete thefunctional simulation in alignment with the MAC sub-layer module.Finally, based on the system platform, test end system the data exchangefunction under normal circumstances, and under the condition of the transmitter endsystem to send special data frame, to verify the data frame processing functions of receiving end system.