High Speed Profiler (HSP)

The High Speed Profiler (HSP) records tunnel surfaces and identifies objects that obstruct the gauge profile. The optical system provides three-dimensional data in real time, using the center line of the tracks as a reference. Maintenance teams then receive very detailed information about the infrastructure.

Two laser modules per sensor head

The HSP sensor can be mounted on the front or back of the inspection car. Its sensor head contains two distance measuring systems. High-frequency modulated laser beams are deflected onto the surroundings by a rotating mirror. A collecting lens focuses the returning light onto two detectors. Phase shift technology is used to determine the distance. The exact position of each measurement point is calculated based on the distance value and the angle of the scanning mirror. A two-dimensional image is derived from the mirror's rotational movement; the inspection car's motion provides the third dimension. 

With a rotation speed of up to 277 revolu­tions per second and a sampling frequency of 1 MHz, each beam measures 3,600 distance values per rotation. Thus, one sensor measures 554 pro­files per second. A dedicated computer inside the inspection car processes and displays the data before transferring it to the inspection car's PC network.

Robust housing

The sensor unit contains a fixed optical window and is located in a hermetically sealed housing. The housing protects the sensor head from dirt or vandalism when the unit is not in operation. The sensor unit is combined with a semi-automatic cleaning system for the optical window, making it easy to regain full accuracy after extended operation periods in a dirty environment. The interface requirements on the carrier are minimal. The HSP design complies with EN 60825-1:2001-01. 

Modular design—complete solution

Several sensor heads can be arranged at the front of the vehicle to cover extreme speed and resolution requirements. For instance, a system consisting of three heads produces a clearance profile every 17 mm at 100 km/h.

Fraunhofer IPM installs the HSP on-site and provides operator training. The delivery includes a supply unit and an industrial PC that automatically stores and processes the data. The data can be transmitted to a network via TCP/IP. The HSP is eye-safe according to IEC 60825.