Train Draft Gear Health Monitoring

Abstract

A train draft gear goes between the coupler and the frame of the car. The train draft gear cushions switching impacts so that the impacts don't damage the train cars. Currently, the inspection of train draft gears is mainly performed offline through visual inspection. Because the major part of the draft gear is hidden inside the train coupler, it requires the disassembly of train coupler to perform the inspection, which is time consuming. Moreover, when there is a leakage inside the draft gear, visual inspection could miss the internal leakage until the leakage is very severe. This paper introduces a Structural Health Monitoring (SHM) system to monitor the status of the train draft gear when the train is in service. The system consists of a set of strain sensors to measure the pulling and pushing force, a data acquisition unit and the upper level analysis software. When the draft gear is mal-functioning, strain signals show different patterns from the signals in normal condition, which can be used by machine learning methods to estimate the health status of the draft gear.