Synthesis of tactical plans for robotic excavation

Abstract

This thesis describes an approach to synthesizing plans for robotic excavators. Excavation tasks range from loading a pile of soil to cutting a geometrically described volume of earth--- for a trench or foundation footing. The excavation task can be stated in terms familiar to researchers in robotics and artificial intelligence: Transform the world from its current state to another state. Two important characteristics, however, distinguish the excavation domain. First, soil is deformable, and, hence, a complete state-space description of terrain to be excavated requires a high-dimensional representation. But, for the state-based representations that traditional planners use, very large spaces are simply infeasible. Second, the response of soil varies immensely, and in general, it is not possible to analytically describe the mechanics of soil motion and its interaction with tools. A soil's shear strength depends not only on its physical and chemical makeup, but also on factors such as t...