Characterisation of Rail Tracks by Means of Hollow Shaft Integrated Acoustic Sensor Systems
Frank Schubert, Fraunhofer Institute For Nondestructive Testing
In the European ACEM-Rail project (Automated and Cost Effective Maintenance for Railway) a hollow shaft integrated acoustic sensor system for rail track monitoring was developed. It contains acoustic and acceleration sensors and allows for high- and low-frequency analysis of rail and track bed condition. The results can be used for short-term repair and long-term maintenance planning.
The technical and structural condition of rail tracks is conventionally evaluated by visual inspection and by complex inspection trains on a regular basis. While visual inspection is time-consuming, expensive and not very reliable, inspection trains are also expensive, interfere with the running train service and are usually limited to surface-near defects such as rail cracking, surface disintegration, corner shelling and head checks. In the paper to be presented a hollow shaft integrated acoustic sensor system will be described that could be used for continuous track monitoring in running passenger or freight trains. It contains acoustic and acceleration sensors and allows for both high-frequency measurement of surface related rail defects and low-frequency analysis of track geometry, track bed condition and bridge integrity. By using this monitoring system complete acoustic track profiles can be stored at frequent intervals and can be compared with former measurements of the same track. From the differences between consecutive runs information about rail geometry, track safety and material degradation can be extracted and used as a basis for short-term repair and long-term maintenance planning as demonstrated in the European project ACEM-Rail (Automated and Cost Effective Maintenance for Railway). The acoustic measurement system is fully integrated in the hollow shaft of a train axle and does not need any additional external mountings. It can be used in national high-speed and low-speed trains as well as in regional trains and trams. It therefore offers the possibility of a cost-effective, regular and area-wide track condition monitoring.
Association for European Transport