A random walk model approach for the wheel-rail contact force estimation

The wheel-rail contact strongly influences the dynamics of the railway vehicles. This interaction is affected by several conditioning factors such as vehicle speed, wear, and adhesion level, and, moreover, it is nonlinear. As a consequence, the modeling and the observation of this kind of phenomenon are complex tasks but, at the same time, they constitute a fundamental step for the estimation of the adhesion level or for the vehicle condition monitoring. This paper presents a novel technique for the real time estimation of the wheel-rail contact forces that allows an a priori no knowledge of this kind of mechanism because a random walk model (RWM) approach is adopted and integrated in a complete model based estimator for railway vehicle.