Van de Merwe, Charl ViljoenLe Roux, Johan DerikLimebeer, David J.N.2025-11-202025-11-202025-12Van de Merwe, C.V., Le Roux, J.D. & Limebeer, D.J.N. 2025, 'Locomotive wheel-slip control with slip ratio reference adaptation using model-based estimation', Control Engineering Practice, vol. 165, art. 106597, pp. 1-15, doi : 10.1016/j.conengprac.2025.106597.0967-066110.1016/j.conengprac.2025.106597http://hdl.handle.net/2263/105396This 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.en© 2025 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).LocomotivesRailwaysAdaptive controlParameter estimationModellingArticle