A methodology for the measurement of track geometry based on computer vision and inertial sensors
This addresses the need for efficient and affordable track monitoring in railway maintenance, though it appears incremental as it builds on existing sensor technologies.
The paper tackles the problem of measuring railway track geometry irregularities by proposing a Track Geometry Measuring System (TGMS) that uses computer vision and inertial sensors, enabling non-contact measurement of alignment, vertical profile, cross-level, gauge, twist, and rail-head profile with a compact, low-cost design installable on moving vehicles.
This document describes the theory used for the calculation of track geometric irregularities on a Track Geometry Measuring System (TGMS) to be installed in railway vehicles. The TGMS includes a computer for data acquisition and process, a set of sensors including an inertial measuring unit (IMU, 3D gyroscope and 3D accelerometer), two video cameras and an encoder. The main features of the proposed system are: 1. It is capable to measure track alignment, vertical profile, cross-level, gauge, twist and rail-head profile using non-contact technology. 2. It can be installed in line railway vehicles. It is compact and low cost. Provided that the equipment sees the rail heads when the vehicle is moving, it can be installed in any body of the vehicle: at the wheelsets level, above primary suspension (bogie frame) or above the secondary suspension (car body).