Research On Gnss Positioning For Train Following Operation Simulation Method In Railway Environmental Scenarios

With the development of train operation control system,the on-board positioning mode based on GNSS has become a development trend."Train operation control system based on dynamic interval" puts forward the train operation control mode based on Beidou satellite positioning and vehicle to vehicle communication.Therefore,it is necessary to carry out the laboratory test of corresponding functions before the field test,build the laboratory simulation environment,realize the train following operation based on satellite navigation,and verify the satellite positioning and following performance of the train in complex environmental scenes.The main research contents of this paper include:(1)The train path planning method based on Digital Track Map(DTM)is studied.Based on the fixed application data,the topological model structure of DTM is established,the train operation path generation method based on Depth First algorithm is proposed,and the three-dimensional track data for satellite navigation simulation is generated based on the train operation path.(2)The generation method of space-time relationship of train following scene for satellite positioning is studied.Based on the train dynamics model,the temporal and spatial relationship of train trajectory data is generated.The Train Safe Location Boundary(TSLB)structure for satellite positioning is designed,and the optimized speed function model based on interval speed limit is proposed,and then the time-space relationship data of train following is generated.(3)The satellite positioning environment scene simulation method is studied,the satellite distribution characteristics of train satellite positioning environment scene are analyzed,the visibility information of train satellite positioning environment scene database is constructed,and the satellite positioning environment scene generation method based on position trigger is proposed.(4)Analyze the laboratory test requirements of "Train Operation Control System Based on Dynamic Interval",and design the function,interface and interface information of GNSS-based Train Following Simulation(GTFS)based on satellite positioning.Developed the GTFS software,which can be divided into 6 modules according to the functions,respectively: Train path planning module,train space-time relation generation module,train following scene generation module,satellite positioning environment scene module,train space-time relation generation module,train following scene generation module,satellite positioning environment scene module,satellite navigation simulator signal control module and method and simulation verification module.Based on the DTM data of Hamu railway,this paper designs two laboratory test sequences to verify the performance of satellite positioning and train following scene generation.The satellite positioning performance test sequence includes four scenes: open scene,"half the sky" scene,cutting scene and tunnel;The simulation results show that the positioning errors of the train in the open scene,the "half sky" scene and the cutting scene are 0.71 M,1.46 M and 1.25 m respectively(95% confidence probability).The train following performance test sequence includes three scenes: open scene,"half the sky" scene and cutting scene;The simulation results show that the time for the train to reach the tracking state in the "half sky" scene and the cutting scene is 92.9s and 84.6s respectively.Compared with the open scene of the control group,the time for the subsequent train to reach the designated position of Chaidaer II station increases by 7.2s.The GTFS software and two test sequences designed in this paper satisfy the needs of satellite positioning and tracking test in laboratory environment.70 Figures,24 Tables,51 References...