Assessment of the efficiency of unmanned road machines in the construction and repair of transport infrastructure

Abstract

Trajectory scatter of a compaction machine under manual control forces the overlap of adjacent compaction strips to be assigned with a margin, and this margin is paid for by a loss of shift output of the machine set. The practice of assigning a 0.20 m overlap at a standard deviation of the drum lateral position of 0,17 m leaves about one twelfth of the pavement area without the required number of roller passes. The purpose of the work is a quantitative assessment of the transition to unmanned control of an asphalt paver and a set of rollers against the criteria of shift output, compaction uniformity and unit costs. The calculation is performed on the author's model of a machine set that combines a probabilistic description of lateral deviation, an exponential relation between residual air voids and the number of roller passes per track, and a balance comparison of paver and roller productivity. Reducing the standard deviation to 0.043 m increases the effective width of the compaction strip by 14.0%, raises the shift output of the set from 7 649 to 9 156 sq. m and reduces the share of area with a pass deficit from 12,0 to 1,8%. Unit costs decrease by 8,4% at a simple payback period of the on-board systems of 2.4 years. The combination of output growth with improved compaction uniformity shows that trajectory accuracy removes the technological trade-off between the speed of works and the quality of the layer, which under manual control cannot be eliminated by the choice of the compaction mode.