Analysis And Design Of AFDX End System Protocol Stack

With the complexity of avionic systems increasing, it also brings forth higher requirements for the width of avionics data bus. The successful trial of using Avionics Full Duplex Switched Ethernet(AFDX) has escalated the avionics system into a new highly integrated era. End system performed as an important part in AFDX network,however AFDX protocol stack plays an important role in AFDX end system design.UDP、IP layer of AFDX protocol stack functions the same as common Ethernet. To eliminate the uncertainty of Ethernet and guarantee the safety and reliable of air communication, new functions are added into virtual link layer, so it is the key point of end system design. At present, our country is in the critical period of vigorously developing large and medium-sized aircrafts, thus it will play a positive role and have a significance meaning for us to develop large aircrafts with independent intellective property rights once we begin to research and finally use the AFDX end system virtual link layers.First, traditional avionics data bus, such as ARINC429 and 1553 B and new avionics data bus AFDX’s development status and advantages and disadvantages are analyzed. Compared with the other avionics data bus, such as ARINC429 and 1553 B,AFDX not only increases network bandwidth, effectively avoid network bottlenecks,but also significantly reduces the weight and cost of aircraft. Both of the Airbus and Boeing, have coined AFDX to its new aircraft recently, such as A380,A400,and Boeing-787.Therefore the AFDX network’s great superiority and the necessity to study and develop AFDX network are demonstrated. Lacking of real-time and deterministic requirement of the Ethernet, and in order to meet the requirements of aviation data bus,the AFDX network adopts key techniques that are fully different from Ethernet in implementation, the real-time and deterministic requirement of AFDX network is guaranteed fundamentally.Second, make a simple introduction to the virtual link layer of AFDX end system in AFDX network on the importance of the virtual link layer protocol, digital AFDX end system to carry on overall analyze, put forward the digital AFDX end system of virtual link layer framework of the overall structure put forward the main functions of AFDX end system such as data transceiver, traffic shaping, virtual link scheduling, integrity checking, redundancy management and so on. The digital AFDX end system is mainlydivided into four parts, driving module, transmission module, communication configuration module and error warning count.Finally, using OPNET network simulation software for the simulation of AFDX network. Make a communication test of an AFDX network system built by AFDX end system and switch. Verify the function and performance of design of AFDX digital end system and prove the correctness and practicability of the design of AFDX end system.The results of all the parameters show that the AFDX network fully meets the requirement of high real-time and deterministic in aviation data bus. The AFDX network is the best choice for the next-generation aviation data network.