Offline and Online Measurement of the Geometries of Train Wheelsets: A Review

Train wheelset is one of the most important and costly-on-maintenance components in the rolling stock. Timely assessment of the wheelset wear can prevent the wheelset wear induced derailment, as well as enable the scheduling of optimal maintenance strategy, like when to perform reprofiling or when to replace, to maximize availability, minimize downtime, and minimize maintenance costs. The geometric parameters of wheelset that need to be constantly measured include wheel diameter and wheel profile. Various measurement methods, from the classical handheld gauges to machine vision-based sophisticated online noncontact vision systems, have emerged for the timely measurement of the geometrics of train wheelsets. Despite the significant development on train wheelset geometrics measurement methods in the past decades, a systematic review is not available yet. In this paper, we systematically review reported gauges and systems for measuring the geometrics of train wheelsets. Forty-six research articles and 13 granted patents published from 1990 to 2022 were reviewed. We provide a categorization of the measurement methods, and then detailly reported the gauges and systems based on offline and online categorization. At the end, the limitations of the state-of-the-art and the research prospects are given.