The Study On A Portable Instrument Of Rail Wear Profile And Cant

The wheel/rail rolling contact behavior is the basis of train traction, braking and guidance. Meanwhile, it also causes the rail surface changes, which is bad to the wheel/rail dynamic performance. Therefore, measuring the rail head shape, calculating rail’s vertical and lateral abrasion are important to the railway safety and economical operation. The purpose of this paper is to invent an instrument to increase the rail head’s measuring rang and improve the abrasion accuracy. It includes the following jobs:Firstly, according to the design requirements of measurement range and accuracy, the measurement model and the inverse kinematics model have been established. After the parameters of five-bar mechanism are simulated for optimization, a portable rail profilometer with double probe is investigated and designed, which is able to measure the whole rail’s head and its jaw for the50kg,60kg,75kg rail.Secondly, based on the preliminary Matlab simulation results, the mechanical structure of the instrument has been designed in Auto CAD., including the design of the planar articulated five-bar mechanism with double probe, structure of the probe, stop bit and connecting rod, etc. Further make sure the rationality of the instrument’s parameters, based on the collision test.Thirdly, data processing algorithm of the instrument has been simulated in Matlab, including radius compensation algorithm, digital alignment algorithm, etc.Finally, according to the analysis of error source, error model has been established. Motion process have been simulated, the quantization error and single factor error have been analyzed.The profilometer, base on double L-five-bar mechanism, can measure the whole rail’s head and its jaw. After using the curve digital alignment, the Vertical and lateral wear abrasion of the rail head have been calculated accurately and conveniently.