Research On The Railway Track Irregularity Measuring Based On MEMS

Railway track system is the important transportation infrastructure and plays a foundational role during the country economic development process.Because of the frequent passage from heavy train and the track bed settlement,the railway track condition tends to deteriorate and affect track irregularity.Track irregularity greatly influences the train safety and brings discomfort to train passengers,so it needs to be detected and eliminated quickly and accurately.Recently,the traditional method by using total-station plays a foundational role in the track irregularity detection.This measuring system can measure the track with 1mm accuracy in the stop-and-go mode.With the rapid growth of high-speed line operating mileage,total-station measuring system cannot meet the track irregularity detection demand due to its low measurement efficiency.At present,high precision inertial navigation system as a new technology is include in track irregularity detection.This system can provide accurate and rapid measurement of railway track with sub-millimeter accuracy.However,the cost of high precision inertial navigation system is very high for large-scale promotion and application.In this case,this paper focuses on the short-wave irregularity and applies MEMS inertial devices to the railway track irregularity detection,which can greatly reduce the cost and is conductive to the promotion and application.In this research,a railway track irregularity measuring system based on MEMS inertial device is designed.Experiment has been conducted to verify the stability and precision of the whole measuring system.In order to improve the measurement accuracy of this detection method,this paper uses the design heading angle auxiliary,3D velocity constraint and constrained adjustment to reduce measurement errors based on the railway track strong constrains.According to the analysis of multiple measurements over the same section of track,MEMS surveying system has excellent attitudes and short-wave irregularity repeatability.The differences of attitudes are smaller than 0.015 deg(la),and the whole precision of short-wave irregularity are less than 0.5 mm.By contrast with the reference system,MEMS surveying system can maintain the relative measurement accuracy of sub-millimeter level,such as cant,gauge and short-wave irregularity,which achieves the accuracy of short-wave irregularity detection in practical engineering applications.Compared with the high-precision inertial navigation system,MEMS can greatly reduce the measurement cost,which is conductive to the application and the general spreading of this technology.