Measurement of railroad track irregularities using an automated recording vehicle

This paper presents the design, construction and experimental validation of a scaled railway vehicle for the automated and quick survey of the geometry of an experimental scaled track. The method, that can be extended to full scale tracks, validates the measurements of the automated recording vehicle (ARV) by comparison with respect to a precise but slow manual measuring method (MMM). The two-axle vehicle, which is powered by a brushless DC motor, has its leading axle instrumented with a LVDT, an inclinometer, a reflector and a precision encoder. These sensors, together with the help of a total station, allow the measurement of the scaled track geometry and its irregularities following an optimization procedure that first determines the ideal track centreline. The ARV has been tested on a scaled track and its measurements are validated with the MMM results showing a good agreement between both approaches.