The utility of continual monitoring of track geometry from an in-service vehicle

An inertial measurement unit (IMU) comprising three accelerometers and three gyroscopes all of good quality, attached to the bogie of an in-service railway vehicle and suitably processed in conjunction with a tachometer signal and a GPS feed, tracks the location, orientation and trajectory of the bogie. Using this data, the condition of the track geometry can be assessed. By monitoring this data as the vehicle moves around its normal operating route(s), changes in track geometry can be tracked with a relatively fine granularity in time. The research described here details the uses to which such fine granularity track geometry data could be put, and the development of automated processing to extract the desired information. The aim is to observe track geometry through renewals, degradation and maintenance to understand how faults develop and how effective maintenance has been.