GPS means accurate job

Thanks to advances in gps technology, a difficult 1,2 km section of the new L546 highway has been completed by a Vögele Super 1900-2 paver fitted with its new Navitronic Plus 3D machine control system.

The section by-passes the village of St. Leon-Rot, Germany and included tight bends and several changes in the transverse profile. Working automatically the Super 1900-2 was fed the design data in digital form, with no need to carry out time consuming surveying and preparation work.

The 3D control unit was connected to Topcon's mmGPS positioning system, which combines satellite-and laser-based measurements. To determine the 1900-2's position the mmGPS unit uses receiver that locks to both the US's GPS and Russia's GLONASS satellites, ensuring a sufficient number are in view at all times. While this system could only achieve centimetre accuracy the mmGPS uses an additional laser receiver to obtain extra information for the elevation. The machine's location can therefore be calculated to within millimetres.

This information was fed into Vögele's Navitronic Plus, which then took over control of the 1900- 2. Any deviation was corrected automatically, with minor deviations in terms of screed position corrected by way of extending the screed.

In the event of major deviations the Navitronic Plus assumed control of the paver's steering and put both the machine and the screed in the correct position.

The 7,6 to 7,8 m wide section was paved at full road width, with a receiver fitted to each of the screed's arms to pick up the position as well as the grade and slope. A special challenge was the bends and the varying crossfall, with slope angles up to 8%.