Simulation-based Rover Performance Evaluation and Effects of Terrain Modelling

In this work we investigate the effect of terrain modelling on the performance of planetary rovers, for the evaluation of design concepts under typical rover operation tasks. These tasks include: (1) straight line motion on a flat terrain or climbing a given slope; (2) climbing over a rock with one wheel-set while the other wheels move on flat or inclined terrain. The primary characterization and comparison will be based on performance measures that characterize the vehicle-terrain interaction such as energy expenditure and efficiency. We will use three rover concepts that are either already space-qualified or in the development phase. The analysis is based on implementations in CMLabs’ Vortex, a dynamics simulation environment for complex mechanical and mechatronic systems. Vortex can be used to model the contact of wheels under various terrain conditions. We will particularly focus on motion on soft terrain and investigate the physical phenomena exhibited by such terrain and the possibilities to model these with the primary purpose of representing the effects of the terrain on the rover behaviour. We look at the effects of various terrain modelling approaches on the performance of rover concepts, and their applicability and validity for different operating conditions.