| Track status directly affects the operation safety and ride comfort of track vehicle system,so routine detection and long-term tracking monitoring must be carried out.With the increasing service time of high-speed railway,all kinds of track problems begin to appear.It is necessary to establish a more perfect and complete detection and monitoring system guided by engineering application.It also puts forward higher requirements for the detection of new and under construction railway networks.Therefore,the dynamic detection technology dominated by high-precision mobile equipment will play a more important role in the condition detection and monitoring of railway infrastructure.In addition to data acquisition,another core of dynamic detection technology is multi-source detection data analysis.In order to better understand and utilize the test data,using a large number of frame traverse data,who is collected through high-speed comprehensive detection of trains,the research on the track service status evaluation method based on the performance evaluation of the EMU is carried out.the premise of this study is to filter out the elastic vibration component in the original signal through filtering and analyze the lateral vibration characteristics of the frame under typical working conditions.（1）The differential equation of vehicle system dynamics is established,and the calculation formula of the bogie suspension mode frequency in the undamped state is obtained by combining the free vibration theory of the mechanical system.Combined with the modal frequency and measured data obtained according to the technical parameters of the real EMU,the filtering frequency band that is applicable to the lateral response data of the bogie and can effectively improve the signal-to-noise ratio is determined: 0.1～20 Hz.（2）From the perspective of time domain and frequency domain,the lateral vibration characteristics of the bogie under typical working conditions are analyzed and discussed,including different design speed lines,different track types,different radius curves of the same line and common wheel treading before and after wheelset-lathing,which helps to master the relevant vibration laws preliminarily.（3）At present,peak value and average value are often used for track state management,But when the track direction irregularities have same amplitude and different shapes,it always leads to different bogie lateral responses.In view of this,an evaluation method of Track Irregularity Based on equivalent impact rate is proposed,and combined with a large number of data analysis results,the recommended thresholds of lines with different speed levels are given respectively.The analysis results of measured data show that this method can effectively identify and locate the bad position of local track state affecting the transverse vibration of the bogie.（4）The equivalent impact rate index focuses on depicting the amplitude characteristics of the bogie lateral displacement,which blurs the segment characteristics.In order to achieve the evaluation of the state of the track section,the method of indirectly realizing the state evaluation of the track section by evaluating the lateral motion stability of the EMU is proposed from the aspects of energy and signal composition by means of Joint Time-Frequency Analysis.Considering that the incidence of lateral less-stability problems is not high,combined with the characteristics of the bogie lateral displacement,the low frequency ratio is proposed which can be used to search for possible problem sections before analysis,so it can improve the diagnostic efficiency.The analysis of measured data shows that the method is effective and reliable. |
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