Locomotive velocity estimation for a slip control purpose by an unscented Kalman filter

The train velocity is needed to be known for many purposes like the train safety systems or a slip control. The train velocity is typically determined from wheelsets velocity. The wheelset velocity is different with the train velocity due to a slip velocity that is needed for a force transmission between wheels and rails. The train velocity measured by this way is the only estimation of the train velocity. If the train velocity is needed for a slip control, the actual velocity has to be known with the smallest possible delay. For the purpose, a novel method based on the unscented Kalman filter is presented. Nonlinearity between the wheel velocity and the train velocity is analytically derived. The simulation results are based on the measured data.