Track maintenance works based on track geometry recordings are essential to enhance the safety and comfort of railway transportation. The track condition monitoring system is mainly used for the choice of area needing track tamping works for the purpose of the good riding comfort. An advantage of car-body acceleration measurement devices is their simple structures, which make it easier to carry out maintenance. However, the car-body acceleration waveform is considerably different from track geometry. This paper demonstrates the possibility to estimate the track geometry of Shinkansen tracks using car-body motions only. In an inverse problem to estimate track irregularity from car-body motions, a Kalman Filter (KF) was applied to solve the problem. Estimation results showed that track irregularity estimation in vertical direction is possible with acceptable accuracy for real use.
This paper summarizes the track-condition-monitoring system for conventional and high speed railway used in Japanese railway. For conventional railway, rail irregularities are estimated from the vertical and lateral acceleration of the car body. The roll angle of the car body, calculated using a rate gyroscope, is used to distinguish line irregularities from level irregularities. Rail corrugation is detected from cabin noise with spectral peak calculation. A GPS system and a mapmatching algorithm are used to pinpoint the location of faults on tracks. Field test using in-service vehicle was carried out to evaluate the developed system. The results show that the condition of rail irregularity and rail corrugation can be estimated effectively. For high speed railway, shinkansen, the track condition monitoring system called RAIDARSS 3 is introduced.
We have developed three inertial measurement processing techniques to measure the longitudinal level of tracks using the devices mounted on the commercial shinkansen trains. Two of them, labeled as the "Frequency variable difference filter" and the "Speed variable moving summation", employ digital processing, while the other employs analogue processing applying a frequency variable low-pass filter. Through a series of the simulation tests, the above all methods were found to be capable of deriving a 10 m versine longitudinal level directly from the measured acceleration with high precision without causing any waveform distortion. An experimental prototype of a digital inertial device applying the "Frequency variable difference filter" that can help to minimize the processing load was produced, and its reliability was investigated. As a result, the output by means of the proposed prototype revealed good correlation with the data collected from an existing track geometry car. After the successful test results were obtained, the devices have so far been manufactured and installed in six N700 commercial trains. The repeatability was also found to be excellent, thus the device is expected to detect even a slight change of the track.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.