Locomotive wheel-slip control with slip ratio reference adaptation using model-based estimation

This paper investigates the wheel-slip control of locomotive traction systems in the presence of uncertain wheel-rail rolling contact conditions. A linear estimator is used to produce estimates of the wheels’ slip ratios and adhesion coefficients. These estimates are used as part of a slip ratio reference adaptation scheme that provides a reference to an adaptive PI controller. The control architecture is intentionally designed to be suitable for practical deployment in industrial settings, where simplicity and reliability are essential. A detailed pitch-plane simulation model is used to validate the controller performance. The results indicate that the estimator-controller combination can prevent unstable slip over a wide range of adhesion conditions, thereby preventing damage to the wheels and rail while ensuring maximum adhesion.