Structural Features

Detecting surface distress on the road

Data on the condition of road surfaces form the planning basis for maintenance work on the road network. The focus lies on the detection of damage, patches, potholes, or even tiny cracks. The earlier they are detected, the lower the maintenance costs - the safer our roads will be. These damages or distress can be detected using high-resolution image data of the road surface.

Pavement Profile Scanner PPS-Plus

The PPS-Plus is our latest development in the field of road measurement technology. This measuring system provides the high-resolution images required for distress detection. The scanner is mounted on a measuring vehicle. With a single, eye-safe laser beam, the PPS-Plus scans the road surface over a width of approximately 4 meters. The road is scanned line by line. The intensity of the light scattered back from the road surface is captured at a measuring frequency of 64 MHz. At a scanning frequency of up to 800 Hz, this results in at least 80,000 measurement points per profile. At a speed of the measuring vehicle of 80 km/h, the scanner produces a photorealistic image of the road surface with a resolution of approximately 1.2 mm × 1.7 mm. Since cracks normally have an extension, structures in the submillimeter range can be reliably detected. The measuring vehicle operates in regular traffic - inner-city roads as well as motorways can be monitored in this way without impairing traffic.

Laser scanners replace cameras with flash lamps
The PPS-Plus is an alternative to the camera systems still common in mobile mapping. These are equipped with an array of flash lights and often extend over the entire width of the road. Another point: theses systems are extremely sensitive to ambient lighting and exhibit problems with the wide optical variety of the road, ranging from dark asphalt to bright road markings.

Determining additional parameters with a single system
As standard, the PPS-Plus is fused with the 3D measuring unit PPS by means of a patented approach, which allows not only high-resolution intensity images of the road surface but also the determination of longitudinal and transverse evenness from one device. Thus, three of the four parameters proposed for pavement condition assessment can be determined with one system.

With the Clearance Profile Scanner CPS, Fraunhofer IPM also offers a completely encapsulated 360° scanner that captures the environment with millimeter accuracy. All of our sensors can be integrated into the Mobile Urban Mapper MUM together with cameras and precise positioning technology from Fraunhofer IPM, thus providing all data of the road and its surroundings in a consistent data stream.

Fully automated data evaluation
Through the integration of 3DAI – our Deep Learning Framework with automated interpretation of 2D and 3D data – we enable an automated, efficient evaluation of the extensive data sets. The result can, for example, be a map that only shows objects such as street assets or cracks as required.