Design and implementation of a novel apparatus for terramechanics studies of helical scrolls

Modeling the force interaction between a wheel and the ground is necessary when evaluating the effec-tiveness of a vehicle's mobility on challenging terrain. Soft soils with low bearing strength are a partic-ularly difficult medium for wheeled vehicles. Helical scrolls have shown promise as an alternative to wheels which can work across a range of terrains, warranting a detailed terramechanics study to model their capabilities. Most of the existing terramechanics literature is limited to wheels and often employs an apparatus to study single wheels in a fixed geometry. This paper describes the design and implementation of a novel apparatus capable of housing a range of scroll geometries and configurations. The apparatus is comprised of a soil container, carriage to drive the scroll in two operating configurations, and a surrounding frame that enables both vertical and horizontal motions of the carriage. The carriage is outfitted with a drive system and instrumentation to measure the sinkage, stress, and drawbar pull values required for a terramechanics characterization. Initial stress-sinkage curves for three different scroll configurations align with expected results and provide a proof of concept that the proposed apparatus can successfully measure differing geometric parameters and can be used for further terramechanics characterizations. (c) 2023 The Authors. Published by Elsevier Ltd on behalf of ISTVS. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).