Excavator

Abstract: Excavators are used for the rapid removal of soil and other materials in mines, quarries, and construction sites. The automation of these machines offers promise for increasing productivity and improving safety. To date, most research in this area has focused on selected parts of the problem. In this paper we present a system that completely automates the truck loading task. The excavator uses two scanning laser rangefinders to recognize and localize the truck, measure the soil face, and detect obstacles. The excavator's software decides where to dig in the soil, where to dump in the truck, and how to quickly move between these points while detecting and stopping for obstacles. The system was fully implemented and was demonstrated to load trucks as fast as human operators.

Abstract: Automation of excavation operations can be realized by an automatically controlled excavator system that is able to perform autonomously a planned digging work and to quickly comply to interacting forces experienced during excavation. The development of such an automated control system is usually based on a dynamic model of the system that describes the motion with time. A dynamic model for an excavator that is needed for the controller design can be derived by applying Newton-Euler equations to each link in succession. The model obtained describes the motion of the excavator. It corrects several shortcomings that appear in previously published excavator model. On the basis of the model derived, a proportional-differential controller is designed that makes the bucket to track a specified trajectory. It can be used to automate the machine operations, for example, for terrestrial and planetary excavations as well as for mining applications.