Kinematic modeling of a track geometry using an Unscented Kalman Filter

New data filtering methods based on the Kalman filter concept are investigated for application to track geometry, where a track trolley is normally used to measure the track coordinates, cant and gauge, among others. Continuous as well as discrete measurements of the trolley are conceptually modeled, and the accuracy of the sampling scheme is also investigated. For this, a modified kinematic model of the track geometry involving transition and circular curves is proposed based on the tangential as well as normal acceleration, and both a nonlinear Extended Kalman Filter (EKF) and an augmented Unscented Kalman Filter (UKF) are applied to optimize the measured data. The efficiency and accuracy of the proposed models of EKF and UKF having a new kinematic equation is verified with ideal track geometry and with statistical methods including Root Mean Square (RMS). In addition, field measurement data are also considered to check the applicability of the models. Finally, future work on track geometry modeling based on a high-speed measurement vehicle is briefly outlined.