Paver with material supply and mat grade and slope quality control

Abstract

An asphalt paver includes a microprocessor controlled integrated control system to control both the operation of a tractor unit of the paver and the positioning of the screed during a paving operation. A paver operator may operate the paver and monitor the screed position with respect to a grade reference. The correction of grade or transverse slope errors is accomplished by monitoring the linear advance of the paver and then measuring a any deviation of the screed with respect to a grade reference. The amount of vertical deviation and the linear advance since a most recent correct reading allows a rate of deviation per unit advance of the paver to be determined. A correction is applied as a change in the angle of attack of the screed, the change being equal and opposite to the determined rate of deviation. A transverse slope change is also measured directly at the screed. A measured transverse angular deviation is translated into a vertical deviation which is then translated into a rate of deviation per unit advance of the paver with a corrective twist being applied to the screen to offset the deviation. Advantageously dual grade sensors and dual slope sensors are contemplated to provide an automated microprocessor controlled grade and slope control in accordance herewith.