3D Clearance Profile

© Fraunhofer iPM
The scanning data provides information on objects interfering with the clearance profile (marked red).

Shifts in the track bed or objects protruding into the track area pose a danger to rail traffic. This applies to tunnels or platforms as well as along railway lines, where vegetation can protrude into the train corridor. In order to maintain the specified clearance profile, it is measured at regular intervals by special measuring trains. For this purpose, Deutsche Bahn (DB) uses the LIMEZ clearance measuring train, equipped with cutting edge measuring technology by Fraunhofer IPM.

Clearance Profile Scanner CPS / High Speed Profiler HSP

The Clearance Profile Scanner CPS and the High Speed Profiler HSP record the position of the track bed and the clearance profile of railway tracks – in other words, the limits specified around the track that have to be free of obstacles.

The laser measurement system CPS is installed on the vehicle and operates without contact. It scans the clearance profile in a range of almost 360° perpendicular to the direction of travel and references the data to the center of the track. The laser scanner performs 200 profile measurements per second - the high-speed variant HSP even 554 profile measurements. In addition to the clearance profile, the system also records objects near the track. The data is provided three-dimensionally in real time and forms the basis for maintenance work.

Additional moisture detection

The extended version of the clearance profile scanner, CPS-Plus, uses two different wavelengths for distance measurement. The measurement signals can be used to derive information about the surface moisture, e.g. on tunnel walls.