Nonlinear Filter-Based Estimation of Wheel-Rail Contact Forces and Related Considerations using Inertial Measurement Unit

Abstract

Background and Objectives: Rail vehicle dynamics are significantly influenced by the forces at the wheel-rail contact interface, particularly the wheel-rail adhesion force, which is critical for effective braking and acceleration. Continuous monitoring of this force is essential to prevent infrastructure damage and enhance transportation efficiency. Given the challenges of directly measuring adhesion force, alternative methods using state observers have gained prominence. The choice of model and estimator efficacy are vital for accurate variable estimation. Methods: In this study, the dynamics of the wheelset is simulated in the presence of irregularities that can be encountered in the railroad. Estimation of wheel-rail adhesion force is done indirectly by nonlinear filters as estimators and their accuracies in the estimation are compared to identify the better one. Meanwhile, inertial sensors (accelerometer and gyroscope) outputs are used as measuring matrix and employed to simulate actual situation and evaluate the estimators’ performances. The proposed approach is implemented in MATLAB to assess the accuracy and effectiveness of these estimators in determining states and variables. Results: The proposed method effectively utilizes longitudinal, lateral, and torsional dynamics to estimate wheel-rail adhesion force across varying conditions. Experimental results demonstrate high precision, rapid convergence, and low error rates in the estimations. Conclusion: In this study, the identification of the wheel and rail contact conditions is carried out by analyzing the dynamic characteristics of the railway wheelset. The results of proposed method can lead to decreasing wheel deterioration and operational costs, minimizing high creep levels, maximizing the use of alreadyexisting adhesion, and improving the frequency of service. It is worth noting that the proposed method is bene