Micromechanical Modeling of the Interaction of a Soil-Rigid Wheel System

Abstract

Wheeled mobile robots are required to negotiate various types of terrain during planetary exploration missions. The associated mobility is a direct function of the wheel—terrain interactions especially in rough landscapes. This paper presents preliminary results of an ongoing study of the interaction of a rigid wheel of a robot with deformable terrains based on a micro-mechanical modeling of the underlying soil. Analyses were conducted under 1 g as well as 0.375 g to compare Earth and Martian gravitational conditions. The performed simulations provided an insight into the patterns of soil-wheel interaction. The stress distribution as well as particle movement beneath the driven rigid wheel showed a response heavily dependent on the gravity level. These simulations also furnished valuable formation on wheel sinkage in terrain.