Research On Hardware In The Loop Simulation Technology Based On OPNET

HITL means that the physical hardware is introduced into the simulation system,It links virtual system and real network as a unified system and the network data stream can flow between them.The HITL simulation not only improves the credibility of the simulation but also reduces the cost of simulation.The physical subsystem and virtual subsystem coexists in the system.and they can't identify each other's packet format. Thus, how to translate the packet format between them is the most important problem,which has theoretical and applicable significance to HITL simulation.Real and simulation networks are interfaced with one another in the HITL simulation. This paper describles an interface that enables information of data packets to be exchanged between simulated network and real network.Serveral methods of HITL of Communication Network based on OPNET are introduced and analyzed,of which the merits and shortages are Compared, and some important issues in HITL are noted.Furthermore,a system-in-the-Loop(SITL) simulation method based on OPNET is given to connect the different networks directly.The goal of experiment research is to validate the conclusion of theory research.In this paper,we develop a HITL simulation experiment based on ICMP protocol. The hardware sends ICMP echo requst packets to virtual network and views the response successfully. The results show that packets traveling between the simulated and real networks are translated between real and simulation formats with SITL.Then, the process of how the packet formats are translated on SITL and how the packet are flowed among HITL simulation environment are analyzed.Through simulation,we also collect packet conversion delay,end-to-end delay, throughput and other important parameters,then analyze the simulation results,test the accuracy of simulation, provide objective and reliable quantitative basis.