Development of an innovative weigh in motion system for railway vehicles

The estimation of the axle loads of running railway vehicles in motion is an important topic in the management of railway networks, basically for purposes of safety and maintenance interventions on the track. To this aim, through a reasonable number of specialized measurement stations, the axle load of the vehicles circulating in a railway network can be easily estimated without any significant consequence on the railway traffic. In this work the authors present the development of an innovative algorithm for WIM systems aimed at estimating, by means of track measurements, the axle loads of a generic train composition. The formulation of the proposed algorithm is quite general and it can work on different sorts of track measurements (rail shear, rail bending, vertical forces on the sleepers as well as on a combination of them); consequently it can find application in different typologies of measurement stations. The set of experimental physical quantities chosen as inputs are properly treated by the WIM algorithm through estimation procedures based on least square minimization techniques. This algorithm is shown to be accurate and efficient in a large velocity range and robust as regard the measurement points.