This paper addresses the challenge of autonomous excavation of challenging terrains, in particular those that are prone to jamming and inter-particle adhesion when tackled by a standard penetrate-drag-scoop motion pattern. Inspired by human excavation strategies, our approach incorporates oscillatory rotation elements -- including swivel, twist, and dive motions -- to break up compacted, tangled grains and reduce jamming. We also present an adaptive impedance control method, the Reactive Attractor Impedance Controller (RAIC), that adapts a motion trajectory to unexpected forces during loading in a manner that tracks a trajectory closely when loads are low, but avoids excessive loads when significant resistance is met. Our method is evaluated on four terrains using a robotic arm, demonstrating improved excavation performance across multiple metrics, including volume scooped, protective stop rate, and trajectory completion percentage.
@article{arxiv.2409.18273,
title = {Autonomous Excavation of Challenging Terrain using Oscillatory Primitives and Adaptive Impedance Control},
author = {Noah Franceschini and Pranay Thangeda and Melkior Ornik and Kris Hauser},
journal= {arXiv preprint arXiv:2409.18273},
year = {2024}
}