The Application Of Railway Track Irregularity Detection By GNSS/INS Integrated POS System

Along with the increase of mileage of high-speed railway construction and operation,people’s travelling becoming more and more quick,at the same time,the demanding for ride comfortably and safety becoming more and more high.However,the railway track irregularity is an important indicator to affect the train’s running speed and safety.For railway track irregularity detection methods mainly include the following:large-scale integrated high-speed track inspection car,portable track inspection car,cord and the track gauge and so on.But every way exists shortcomings,large-scale integrated high-speed track inspection car although can measure line overall situation,but not for local as well as the key link for precise measurement,and the number of track inspection car little,technology complex and high cost.Portable track inspection car can accurately measure the small area of the line,but the efficiency is low,and the precision affect by the outside factors(CPIII point accuracy,temperature,wind,etc.),and each moving station can only measure 60 m,unable to test the long wave.Cord and track gauge means backward,low efficiency,and greatly influenced by artificial factors.Thus the rapid development of railway makes the traditional detection ways getting more and more difficult to meet the requirements of practical application,urgent need a new kind of orbital irregularity detection means to improve testing efficiency and accuracy.Currently set Global Navigation Satellite System(GNSS)and Inertial Navigation System(INS)integrated Positioning and Orientation System(POS)is mainly used in aerial remote sensing and vehicle-mounted mobile measurement,with the improvement of precision of Inertial Navigation equipment,the position accuracy of POS also gradually improved.POS system can be directly output carrier high-precision three-dimensional position and attitude Angle information,considering the high sampling rate characteristics of INS,comprehensive consideration of discrete points in turn the position and posture information can redraw the trajectories of the carrier.Carrier platform seamless movement and track,and track of vehicle platform can represent the track geometry,can get high precision data results,and improve the efficiency,achieve the goal of track geometry state detection,which is the railway inspection needed.In this paper,the GNSS/INS integrated POS system application in track irregularity detection are analyzed in the experiment,specific as follows:(1)Using carrier phase observation quantity difference measure,to get the position and speed information of GNSS receiver,and according to railway actual routes for the linear fitting,to get the discrete points,which is matching the measurement of track.(2)Using high order kalman smooth filter algorithm,processing the fitting results of GNSS and the raw inertial navigation data collection by loose coupling,using forword-back-forword three times smooth optimization way to filter,to get higher precision of the discrete points coordinates and attitude information,and to adjust the initial installation angle error of inertial device in the filtering algorithm.(3)Using the POS results,according to the inertial navigation car design parameters and measuring gauge value information to calculate the track inspection parameters,which is similar to the CPⅢ points,both all belong to the local level coordinate system,so as to get around orbit plane coordinate and centerline orbit coordinate,calculating the parameters of the test track irregularity value(super-elevation,alignment,high and low,etc.).(4)Comparing with the results based on the processing results,we can found that the attitude angle and the track irregularity parameter values calculate by each trip raw data is consistent,compared with the results calculate by traditional method track gauge,the data results almost unanimously,and compared with the result precision calculate by portable track inspection car,we can concluded that the track irregularity parameters value calculation results and the accuracy is quite,so as to verify that the method is effective and feasible.