Simulation and experimental validation of a modified terramechanics model for small-wheeled vehicles

Abstract

The ability to model and predict vehicle performance over deformable terrains, which is typically done using terramechanics, is important for planetary exploration, military operations, and off-road vehicle design. This paper details the development of a new vehicle-terrain model that specifically addresses some of the limitations of traditional terramechanics when applied to Unmanned Ground Vehicles (UGVs) with small wheel diameters. Assumptions and limitations of the classical Bekker terramechanics model for wheeled locomotion are discussed. A novel pressure-sinkage model that was recently developed by the authors is detailed and shown to improve sinkage and compaction resistance models significantly. These models are implemented in a numerical simulation, which is used to predict the tractive performance of an experimental UGV. Field tests carried out on sandy terrain are described, and the results are used to validate the simulated predictions.