A study of a rover wheel for Martian explorations, based on a flexible multibody approach

Abstract

Vehicles for planetary exploration have to operate in completely different environments from Earth. For this reason, the design process of the exploration unit has an important role and can affect the requirements of the entire mission for the different space agencies involved. These operations are very expensive and time consuming, so that, over the years, ad hoc CAE methods have been developed to help engineers in the design stage. These methods are used to simulate several working conditions, evaluating which manoeuvres robots can safely perform during their mission. In this framework, a study was performed by Politecnico di Torino and Thales Alenia Space Italia. The goal was to find an efficient way to implement flexibility properties of a special wheel of a Rover for Martian explorations in a commercial (general purpose) MTB code. The ExoMars Rover was considered as case study of this work. When dealing with manoeuvres feasibility analysis, the best compromise between solution accuracy and computational time required must be found. The aim of this study was to explore pros and cons of several techniques which could allow modelling a complex flexible wheel using a commercial general-purpose MTB code. The absolute nodal coordinate formulation was compared with the other reduced-order modelling strategies proposed by the authors to implement the flexibility of a wheel in a multibody model of the full vehicle. Numerical results show good performance of the reduced morphing model in terms of computational time versus numerical accuracy.