Proposal of terramechanics-based wheel model for dynamic sinkage

Abstract

Planetary surfaces are covered with soft soil. So the wheels for exploration rovers easily slip and lose the traction force. Understanding the interaction between wheel and soft soil is important for traction control to make rovers travel long distances efficiently. The interaction between wheel and soft soil has been studied in the field of terramechanics. Since terramechanics-based wheel model considers only the static state of wheel sinkage, the wheel model is not applicable to the dynamic sinkage. Therefore the authors deal with the problems of wheel sinkage and slip. The traction mechanics in the dynamic sinkage is important in order to predict the wheel motion when the sinkage becomes to be the static state. This paper presents a terramechanics-based wheel dynamics model with consideration of the dynamic sinkage. This paper also proposes dynamic wheel models for solving the problem of wheel sinkage and a shear deformation model for solving the problem of wheel slip. This paper evaluates the proposed models by simulation study. The simulation results show that the proposed models are able to solve these problems and they are applicable to the dynamic wheel sinkage. © 2012 The Japan Society of Mechanical Engineers.