Experimental plant guidance and control by kinematic GPS

Laser levels are commonly used in the Civil Engineering field both to replace traditional levelling procedures and to automate construction operations. Such include controlling the height of the blade of construction plant such as a bulldozer, and controlling the height of an asphalt paver. Such automation increases the speed and efficiency of the construction procedure. The advent of Real Time Kinematic (RTK) Global Positioning System (GPS) has opened a whole new field of dynamic control and guidance applications. The paper outlines the recent advances in GPS technology, which have enabled such applications of RTK GPS to become a reality. Tests have been carried out in construction plant control and monitoring applications with a demonstrated precision of the order of a few millimetres. Such real time 3D positioning is now available at rates of up to 10 Hz. The results are compared with those achieved using a laser level and a digital automatic level. Subsequently, the results demonstrate that RTK GPS has the potential of providing precisions of the order of a few millimetres.