The ultrasonic system has been completely developed for on-line inspection and defect detection on railways. The developed system has been successfully installed at NDT inspection train as inseparable part of hydraulic holder. The system is used to detect, localize, classify and mark defects on railways. The following picture represents the holder with ultrasonic probes. The holder was mounted on the hydraulic system that guaranteed the contact with tracks in case the track testing was activated:

Well organized and designed ultrasonic probes are in direct contact with railways surface and due to the special construction offer on-line scanning of railways and safe detection.

As the main requirements the following prerequisites were considered:

• on-line and continuously railways (both sides) scanning at speed in average 60 km per hour,
• surface and subsurface object detection,
• automated object classification,
• on-line database data storage and
• final test notification.

This system development using the ultrasonic NDT method has been made by considering the subsurface defects, cracks, holes and welds which are normally present in the railways. For the ultrasonic signal evaluation new software has been developed. The software contains implemented advanced signal processing methods with variable parameters that guarantee all objects detection. This software contains implemented advanced classification methods used for the separation of detected holes, cracks, defects and welds. All detected objects are automatically stored to the database and the operator can created detailed statistics of presented objects in the tracks.

For the surface defect detection we have developed special cameras with integrated sensitive detectors and implemented image processing algorithms. All presented surface defects are also stored to the database. Both systems are fully synchronized and operator can simply invoke printed version of all detected objects. The main advantage of the created system is the synchronization with GPS data, so we are able to trace and mark all defects, holes and welds that are present in the tracks and show them in the map. Using the presented system the tracks and train transport are safer and service companies has better overview about defect presence on tracks.

Technical features

• Based on multichannel ultrasonic system DIO2000
• Subsurface and surface defect detection
• Automated signal processing and monitoring
• Fast detection speed – up to 60 km/h
• Advanced signal processing algorithms implemented
• Classification of detected objects (defects, cracks, welds, holes)
• Implemented classification standard (object classification according to EN standards)
• SQL database data storage
• GPS based localization
• Automated notification