Dependence of locomotive adhesion force estimation by a Kalman filter on the filter settings

A locomotive needs a slip controller to achieve the maximal tractive effort. Many types of methods are used for this purpose. Some methods use a Kalman filter or other type of estimation. These methods can work precisely and reliably. The Kalman filter provides a filtration of an output signal to eliminate the output signals noise when the Kalman filter inputs are noisy, and a filtration level is required. There is a relation between the Kalman filter filtration level and its delay. The Kalman filter delay can reach over 100 milliseconds. The locomotive slip controller has to react in the order of tens of milliseconds to provide an appropriate function. The high level of filtration and low delay are contradictory demands. The key is to find a relation between the Kalman filter delay and filtration through its covariance matrixes. In the paper is investigated the relation between the filtration level and the time delay. The simulations are made in the Matlab software and based on measured data. (C) 2017 The Authors. Published by Elsevier Ltd.