Research On Simulation Of High-Speed Railway Based On Virtual Reality

With the rapid development of the High-Speed Railway Industry of China,people have the necessity for a deeper understanding of how it operates,and the relevant departments have put forward higher requirements for the efficiency of planning and construction of the high-speed railway.As virtual reality technology becomes more and more mature,the combination of high-speed rail and virtual reality technology brings essential significance.The virtual high-speed railway simulation system is an application of virtual reality,and it can not only provide a useful approach for studying topics such as the marshaling of high-speed railway vehicles,the selection,and design of lines,the simulation operation,but also reduce a lot of practical operations,improve the safety,save human and material resources based on its characteristics of safety,economy,and portability.This research is focused on "people,train and environment" as a whole.Firstly,Maya is used to model the high-speed railway train and the station,and then the previous model is 3D reconstructed in Unreal Engine,compare to Unity,Unreal Engine has a better rendering as a simulation tool.As the simulation terrain is vast,in order to optimize the scene,the Level Streaming was used to optimize the large-scale terrain for the first time by block loading.Then,based on the LOD,the method of eliminating unused LOD is put forward,and the second optimization of scene is carried out by combining texture and material technology.Since there are different elevation values in actual terrain,in order to avoid the phenomenon of embedding in the ground or floating in the air,this research studies the fusion algorithm of terrain model and route line model,furthermore a detailed description of the existing algorithms is realized.The simulation of train motion based on the real terrain is one of the focuses of this paper.First,the simulation model based on the actual terrain is proposed.Because the traditional particle model cannot simulate the movement of the rampway,this paper proposes a rope model based on the actual terrain and then carries out the dynamic analysis of the rope model under three different operating conditions.The simulation of high-speed railway naturally depends on the existence of human beings.According to the operation characteristics of high-speed railway,its stop time is basically short.In order to meet the demand of time,this paper proposed A NF-A* algorithm to simulate the passenger’s on-off behavior based on A* algorithm,combined with Nav mesh and the fastest speed method.Through the analysis of experimental results,the use of level flow and the method of eliminating unused LOD has greatly improved the rendering effect,operation efficiency and decreasing memory consumption;the application of terrain model and route model algorithm makes the fusion effect meet the requirements;through the comparison of particle model and rope model,with the increasing of ramp section,the particle model loses applicability,while rope model can well simulate the operation on the complex terrain;through the analysis of five groups of experimental data,NF-A * algorithm is about 30% shorter than A* algorithm in time,meeting the actual needs.