Author(s)

M. Kobayashi, Y. Naganuma, M. Nakagawa & T. Okumura

Abstract

The inertial method is based on a simple law that states that the double integration of acceleration gives its displacement, and is one of the general methods used for recording track geometry. In the inertial method, a high-pass filter (HPF) is essential to ensure stable calculation of the double integration of acceleration. The previous analog inertial measuring system remained wave distortion because the system used analog HPFs, which had a non-linear phase property. To avoid wave distortion caused by analog HPFs, a new algorithm was developed for digital inertial measurement that utilizes the measurement property of the 10 m versine. A new track geometry recording device using this algorithm was produced, capable of being installed on commercial shinkansen trains. This device, called RAIDARSS 3, measures 10 m versine track irregularities from double integration of the axle box acceleration in real time. If the measured track irregularities exceed the predetermined target maintenance values, the measured values and locations of the irregularities are automatically reported to the train control center and track maintenance depots, and slow speed operation is directed, if necessary. To confirm the measurement precision of this device, an experimental prototype was tested on a shinkansen test train. Results showed that the output of the prototype achieved good correlation with data from the existing track geometry car. The new RAIDARSS 3 track condition monitoring device will be installed on six N700 train sets during fiscal year 2008. Keywords: inertial method, recording track geometry, 10m versine.

Keywords

inertial method, recording track geometry, 10m versine.