Maximum adhesive force control in super high speed train

When the wheels of the train slip on the rails, the torque is decreased to avoid the continuously slipping condition. It is well known that the coefficient between the wheels and the rails has a peak at a certain slipping velocity. Thus, in this paper, we proposed to estimate the friction force and the derivative by an observer, and the optical slipping velocity is estimated. As a result, the torque is controlled such that the train is driven by the maximum adhesive force.