Photonic subsystem for rail track hollows measurement

Abstract

At present, in Moscow metro a track inspection vehicle is used to measure rail track hollows. The main drawbacks of the existing subsystem are low accuracy and contact mode of measurement. To eliminate drawbacks the photonic subsystem for rail track hollows measurement (PHM) is proposed. The PHM consists of two photonic units (one unit on each rail). The photonic unit consists of CCD line, dotty laser and matt bar. The laser pixel reflects from matt bar to line CCD. When the hollow is changed the number of illuminated pixel in camera is change. A communication unit combines outputs of the cameras. It performs conversion from RS-485 levels to RS-232 levels. The central computer executes the hollow value estimation and its comparison with the pattern.