Creep slope estimation for assessing adhesion in the wheel/rail contact

The UK rail network is subject to costly disruption due to the operational effects of adhesion variation between the wheel and rail. Causes of this are often environmental introduction of contaminants that require a wide-scale approach to risk mitigation such as defensive driving or rail-head maintenance. It remains an open problem to monitor the real-time status of the network to optimise resources and approaches in response to adhesion problems. This article presents an on-vehicle monitoring method designed to estimate the coefficient of friction by processing data from on-board sensors of typical rail passenger vehicles. This approach uses a multi-body physics analysis of a target vehicle to create estimators for both creep force and creep, allowing a curve fitting approach to estimate the coefficient for friction from the creep curves. Real-time monitoring of wheel-rail friction coefficient in railway networks are not available and it can mitigate significant operational and maintenance related to low adhesion events. This article presents a friction coefficient estimator based on on-board sensor measurements from typical rail vehicles during normal running conditions. The method uses a curve-fitting on the creep curves to estimate the friction coefficient using multibody-physics simulation. image