Longitudinal / Transverse Evenness

Data on the condition of road surfaces form the basis for planning maintenance work on the road network. The standard data measured during condition assessment and evaluation includes skid resistance, surface distress (cracks, patches, potholes, etc.) and the longitudinal and transverse evenness of the road. For example, the theoretical water depth in ruts causing aquaplaning and consequently a large number of accidents can be calculated from the longitudinal and transverse evenness together with the transverse inclination of the road. Longitudinal and transverse evenness are derived from the detailed three-dimensional height profile of the road surface.

Pavement Profile Scanner (PPS)

The PPS from Fraunhofer IPM generates a highly-resolved three-dimensional height profile of the road surface. The shoebox-sized scanner is mounted on a measuring vehicle above the road surface. With a single eye-safe laser beam, the PPS scans the road over a width of approximately 4 meters. The distance to the road is determined by the transit time between emitted and reflected light. The laser scans the surface 800 times per second perpendicular to the forward movement of the vehicle. Each of the profiles generated in this way consists of approximately 900 to 1,800 measuring points, depending on the selected measuring frequency. Even road unevenness in the range of less than 0.2 mm can still be registered.

The measuring speed allows the vehicle to operate in regular traffic – inner-city roads as well as motorways can be monitored in this way without impairing traffic.

Longitudinal evenness

Using four high-precision distance sensors mounted on a bar, the longitudinal profile of a roadway can be measured in accordance with Federal Highway Research Institute (BASt) standards. Alternatively, as a simpler solution, the PPS can be used in conjunction with a precise positioning system (GNSS, IMU, odometer) to measure longitudinal evenness. This eliminates the need for a settling-in phase, and the measurements cover the entire width of the road.

Additional clearance profile measurement

With our application-specific, customizable Mobile Urban Mapping System (MUM), we offer the ability to integrate various sensors for mapping roads and road environments onto a single platform: The Mobile Precise Scanner (MPS), our latest development, maps the road environment with millimeter accuracy. The fully encapsulated 360° profile scanner generates up to 3 million measurement points per second and scans at a frequency ranging from 10 to 300 Hz with a distance resolution of 1 mm. We integrate profile scanners and road surface scanners, along with cameras and positioning technology, into application-specific complete systems for mobile mapping.

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.