GNSS information can be used to position the cutting edge of a blade (on a bulldozer or grader, for example) or a bucket (excavator), and to compare this position against a 3D digital design to compute cut/ fill amounts. “Indicate systems” provide the operator with visual cut/fill information via a display or light bar, and the operator manually moves the machine’s blade or bucket to get to grade. Automatic systems for bulldozers/graders use the cut/fill information to drive the hydraulic controls of the machine to automatically move the machine’s blade to grade. The use of 3D machine control dramatically reduces the number of survey stakes required on a job site, reducing time and costs. Productivity studies have repeatedly shown that the use of 3D machine control results in work being completed faster, more accurately and with significantly less rework than conventional construction methods.

Chapter 9: GNSS applications and equipment