Robotic Framework for Iterative and Adaptive Profile Grading of Sand

Abstract

This paper studies sand profile grading, a manipulation task to obtain a desired geometric curve in sand. Manipulating sand is challenging because like other amorphous materials, its properties are difficult to estimate and emergent effects such as collapses may occur which both influence the manipulation outcome. To tackle these challenges, humans iterate and adapt their manual actions to the observed material states. In this paper, we propose to replicate this adaptive and iterative approach on a robotic profile grading task. Our results demonstrate that (1) tool insertion adaptation reduces force limit violations during tool-material interactions, (2) grading angle adaptation ensures no undercutting or collisions while allowing for cutting or smoothing the sand profile, and (3) adapting progress speed to task evolution provides a balance between grading precision and execution time. This paper's findings pave the way for generalized and transferable robotic systems manipulating various amorphous materials and automating a larger set of construction tasks and beyond.