Search Results

Automatic/adaptive controls for large earthmoving equipment have been developed, and have proven to be effective in improving the performance of these machines while reducing the skill required of the operators. These controls speed up earthmoving tasks, make it easier for the machines to work at night, and contribute to lower construction costs. Controls suitable for motor graders, scrapers and bulldozers have been demonstrated.

A computer-aided technique is being developed for planning, design, estimating, and scheduling of horizontal construction for facilities required to support military operations. This technique permits the user to quickly analyze possible sites and identify those which would require the least construction effort. Once the user selects the site for a facility, the system can design the earthwork, quantify estimates of each earthmoving function, and generate a construction schedule. The user can choose whether the schedule is to be equipment constrained or completion time constrained. This paper describes the technique, including discussions of site data acquisition, the procedures used for quantifying earthwork and estimating equipment productivity, and correlations of these with a required task sequence to generate a construction schedule.

A closed-loop control system has been designed which will adjust dozer blade penetration to maximize work rate under typical dozing conditions. This paper explains the operation and requirements of such a system referred to as the Automatic Draft Power Controller (ADPC). This system is currently being developed for the Naval Construction Engineering Laboratory for use on large scale earthmoving projects. The control system described in this paper may also be applied to other types of earthmoving equipment besides bulldozers.

CEL has for several years been experimenting with automatic surveying and with retrofit automatic blade control kits for construction equipment. Earlier progress on these kits was presented in SAE Paper 750765. Included in this work is an experimental automatic blade control kit developed for a tractor with power-tilt blade. This paper describes results of recent field trials of the tractor kit conducted to compare and record the efficiency of completing a typical earthwork project utilizing present conventional Naval Construction Force surveying and earthmoving equipment versus the efficiency of completing the same project utilizing the automatic controls kit installed on a dozer and laser surveying equipment. The test project was considered representative of earthwork typically encountered in permanent construction.