A Measuring Method of Track Irregularity for High-Speed Railway Based on Dual-Frequency Laser Interference Technique

2013 ◽  
Vol 552 ◽  
pp. 446-451
Author(s):  
Wen Jun He ◽  
Yue Gang Fu ◽  
Yang Zheng ◽  
Lei Zhang ◽  
Jia Ke Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Reference Method ◽  
Measuring Method ◽  
Dual Frequency ◽  
Laser Interference ◽  
High Speed Railway ◽  
Laser Alignment ◽  
Track Irregularity ◽  
Frequency Laser ◽  
Ray Path

A new measuring method of track irregularity for high-speed railway is proposed by using dual-frequency laser interference technique. The linear deviation between the phase-locked gauging head and the center line of the railway route can be calculated by comparing the phase difference variation of the laser beat signal in the test ray path and the reference ray path when the portable track inspection car is moving forward along the track. While we use laser ranging technique to measure gauge, after processing data, the static irregularity of track will be acquired by changing straightness deviation of phase-locked gauging head into straightness deviation of left-right two tracks. The method is different from the existing techniques for detecting high-speed railway irregularity, such as the inertial reference method, the measuring method of chord and the method of laser alignment; it utilized the accuracy of the time to accomplish the high-precision measurement of the space and achieved innovation in theory.

scholarly journals The Influence of an Integration Time Step on Dynamic Calculation of a Vehicle-Track-Bridge under High-Speed Railway

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 431
Author(s):  
Junjie Ye ◽  
Hao Sun
Keyword(s):  
High Speed ◽  
Coupled Model ◽  
Short Wave ◽  
Integration Time ◽  
Vertical Acceleration ◽  
Dynamic Calculation ◽  
Time Step ◽  
High Speed Railway ◽  
Track Irregularity ◽  
Track Bridge

In order to study the influence of an integration time step on dynamic calculation of a vehicle-track-bridge under high-speed railway, a vehicle-track-bridge (VTB) coupled model is established. The influence of the integration time step on calculation accuracy and calculation stability under different speeds or different track regularity states is studied. The influence of the track irregularity on the integration time step is further analyzed by using the spectral characteristic of sensitive wavelength. According to the results, the disparity among the effect of the integration time step on the calculation accuracy of the VTB coupled model at different speeds is very small. Higher speed requires a smaller integration time step to keep the calculation results stable. The effect of the integration time step on the calculation stability of the maximum vertical acceleration of each component at different speeds is somewhat different, and the mechanism of the effect of the integration time step on the calculation stability of the vehicle-track-bridge coupled system is that corresponding displacement at the integration time step is different. The calculation deviation of the maximum vertical acceleration of the car body, wheel-sets and bridge under the track short wave irregularity state are greatly increased compared with that without track irregularity. The maximum vertical acceleration of wheel-sets, rails, track slabs and the bridge under the track short wave irregularity state all show a significant declining trend. The larger the vibration frequency is, the smaller the range of integration time step is for dynamic calculation.

Stochastic Transverse Earthquake-Induced Damage Track Irregularity Spectrum Considering the Uncertainty of Track-Bridge System

2021 ◽  
pp. 2140004
Author(s):  
Yulin Feng ◽  
Yu Hou ◽  
Lizhong Jiang ◽  
Wangbao Zhou ◽  
Jian Yu ◽  
...  
Keyword(s):  
Simulation Model ◽  
Traffic Safety ◽  
High Speed ◽  
Residual Deformation ◽  
High Speed Railway ◽  
Marquardt Algorithm ◽  
Earthquake Action ◽  
Track Irregularity ◽  
Track Bridge ◽  
Bridge System

The track irregularity spectrum of longitudinally connected ballastless track (LCBT)-bridge systems of high-speed railway was proposed in this paper. First, a simulation model of an LCBT-continuous girder bridge was established by considering the influences of approach bridges and subgrade with track structure. Further, a large number of sample analyses were carried out by taking into account the uncertainty of LCBT-bridge systems and stochastic behaviors of ground motions based on the simulation model. The damage laws of residual deformation of track-bridge system after earthquake actions were studied. Then, an interlayer deformation coordination relationship (IDCR) considering the track irregularity caused by earthquake-induced damage of bearings was developed, and the superposed track irregularity samples were obtained. Finally, by using the improved Blackman–Turkey method and Levenberg–Marquardt algorithm, the LCBT irregularity spectrum, track irregularity spectrogram, track irregularity limit spectrum, and a fitting formula for the track irregularity spectrum on a bridge after the action of earthquakes were obtained. Results obtained from the fitting formula and IDCR were compared, and they indicated that tracks undergone significant high-frequency irregularity diseases after the earthquake action. It was found that the track irregularity spectrum could be roughly divided into three ranges: high-, medium- and low-frequency wavebands. Consequently, this led to an application of a three-segment power function for the fitting of the track irregularity spectrum after the earthquake action. The track irregularity spectrum after the action of earthquakes provides an important theoretical basis for the establishment of seismic design methods for high-speed railway bridges based on the traffic safety performance.

scholarly journals Improvement and In-Situ Application of an Evaluation Method of Ballasted-Track Condition Using Digital 2-D Image Analysis

2020 ◽  
Vol 10 (21) ◽  
pp. 7946
Author(s):  
Bongsik Park ◽  
Yeong-Tae Choi ◽  
Hyunmin Kim
Keyword(s):  
Image Analysis ◽  
High Speed ◽  
Evaluation Method ◽  
Recognition Rate ◽  
High Speed Railway ◽  
Analysis Methods ◽  
Track Condition ◽  
Ballasted Track ◽  
Track Irregularity

The advancement in digital image analysis methods has led to the development of various techniques, i.e., quantification of ballast gravel abrasion. In this study, the recognition rate of gravel aggregates has been significantly increased by improving the image analysis methods. The correlation between the track quality index (TQI), which is the standard deviation of vertical track irregularity and represents the condition of a high-speed railway, and the number of maintenance works was analyzed by performing an image analysis on the samples collected from various locations of a high-speed railway. The results revealed that roundness has the highest correlation with the TQI, whereas sphericity has the highest correlation with the number of maintenance works. The ballast replacement would be performed to improve maintenance efficiency if the abrasion of the ballast aggregates becomes approximately 10%.

scholarly journals Measuring method and analysis of rail roughness in high-speed railway

2018 ◽  
Vol 48 (9) ◽  
pp. 950-958
Author(s):  
Qiang YIN ◽  
ChengBiao CAI ◽  
ShengYang ZHU
Keyword(s):  
High Speed ◽  
Measuring Method ◽  
High Speed Railway

Research of high-speed precision positioning system based on double-frequency laser interference

2015 ◽  
Vol 41 (2) ◽  
pp. 156-161 ◽  
Author(s):  
季林 JI Lin ◽  
侯茂盛 HOU Maosheng ◽  
邱丽荣 QIU Lirong ◽  
马飞 MA Fei ◽  
赵维谦 ZHAO Weiqian
Keyword(s):  
High Speed ◽  
Positioning System ◽  
Laser Interference ◽  
Precision Positioning ◽  
Double Frequency ◽  
Frequency Laser

Three-degree-of-freedom micro-vibration measurement system based on dual-frequency laser interference

2019 ◽  
Vol 27 (7) ◽  
pp. 1435-1443
Author(s):  
陈家键 CHEN Jia-jian ◽  
胡慧珠 HU Hui-zhu ◽  
缪立军 MIAO Li-jun ◽  
周一览 ZHOU Yi-lan ◽  
舒晓武 SHU Xiao-wu
Keyword(s):  
Measurement System ◽  
Degree Of Freedom ◽  
Vibration Measurement ◽  
Dual Frequency ◽  
Laser Interference ◽  
Frequency Laser ◽  
Micro Vibration ◽  
Three Degree Of Freedom

Study on Doppler Velocity Measurement System

2012 ◽  
Vol 562-564 ◽  
pp. 1240-1243
Author(s):  
Jian Chao Li ◽  
Jun Hong Su ◽  
Ming Gao
Keyword(s):  
Measurement System ◽  
Velocity Measurement ◽  
High Speed ◽  
Processing System ◽  
Measurement Range ◽  
High Accuracy ◽  
Laser Doppler ◽  
Doppler Velocity ◽  
Dual Frequency ◽  
Frequency Laser

In order to satisfy the high accuracy velocity measurement requirement, using the improved dual-frequency laser Doppler velocity measurement principle, designed a set of laser Doppler velocity measurement system. System consists of two parts: optical system and signal acquisition and processing system. Through the establishment of dual-frequency laser Doppler velocity measurement experimental platform for testing, the result shows that the method can be carried on the high accuracy velocity measurement which in high speed move object. Measurement range from 0.1 m/s to 50 m/s, the error is less than 2 percent and it could increase the speed measurement range.

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