Algorithm to Estimate the Lateral Position of Wheel-Rail Contact and Corresponding Rail Profile Radius

Abstract

This article develops and validates an algorithm to estimate the lateral position of wheel-rail contact and the corresponding rail profile radius. The lateral contact position and contact radius are two novel rail profile performance measures that enable more refined characterization of the rail profile and its influence on rail wear and vehicle dynamics. Leveraging recent advancements in rail profile monitoring techniques, the algorithm contributes to rail maintenance research and practice by developing new measures of performance based solely on commonly available rail profile data. The algorithm developed in this article is an automated process that estimates the lateral position of wheel-rail contact and the corresponding rail profile radius along a rail segment. It uses measured rail profile data as an input and applies rigid contact theory to model contact between a linear wheel profile and the rail profile. The lateral contact position and contact radius are calculated using computer programming that provides graphical and numerical results on a profile-by-profile basis as well as summary statistics for each rail segment. This methodology produces expected results when subjected to validation tests. The validation process analyzes the rationality of algorithmic output against a series of expected results using rail profile data from selected tangent segments of a closed-loop captive-fleet North American rail transit property. The algorithm output does not significantly deviate from any of the expected results, and as such, the algorithm is considered validated.