Research And Implementation Of Distributed Flight Simulation System Oriented Real-Time Communication Middleware

Traditional flight simulation system used to adopt centralized simulation mode and virtualized software design method which require software design of high level and excellent hardware performance,leading to low design efficiency and high failure rate,then adopting distributed structure would be necessary;For simulation of distributed system,one of the most important part is inter-node communication,but traditional communication method like Pipe and Socket can not meet the requirements of throughput,functions,expansibility and real-time performance in large-scale and high-level real-time flight simulation system.Based on distributed simulation environment,this thesis presents the process of design and accomplish the DDS-based communication middleware;As well as design and complete distributed fight simulation system,accomplish a simplified robust design n to assist test;Then presents the test result which indicates that all the communication middleware indexs meet the requirements on the end of this thesis.Main content as follow:(1)Researched on available communication method,then adopts DDS-based middleware method.Compared RTI-DDS with OpenDDS,based on RTI-DDS,additional with ACE framework of OpenDDS,RTI-DDS gains better mutil-platform ability;Based on ACE framework,adding DDS-network-layer,designing modules from configuration,communication,data,logging and storage,in the end,acquired ACE-frame and DDS-based communication middleware.(2)Researched on operating mechanism of Communication middleware discovery,compares simple discovery algorithm,Bloom filtering algorithm and content-based filtering algorithm,based on content-based filtering algorithm,takes reference of hash-table of Bloom filtering algorithm,design local hash dictionary,reducing the amount of communication data,improving the efficiency of communication middleware.(3)Researched on QoS strategy of communication middleware,of which especially the application,then proposes construction method of QoS strategy model,which based on two-dimensional-decision-making-tree model,designs linear and nolinear switch,optimizes the model by linear regression and finally generates available QoS policy group.(4)Researched on robustness of distributed flight simulation system,this thesis designs data-source module,which connects with flight simulation mudle,then takes reference of taguchi-method,adds functions of fault-diagnosis,with the running of data monitor software,this thesis verifies the functions and real-time indicates in the end.Proved through repeated simulation tests,the usage of optimized ACE framework maks communication middleware able to gain better multi-platform ability,communicating mismatch system nodes,based on QoS strategy model,two groups of QoS strategy,high-throughput and low-latency generated,for the robust design,system is able to respond to data and operational errors in emergency;in summary,all the results of throughput,delay and packet-loss-rate meet the requirements of system.