Compaction-Based Deformable Terrain Model as an Interface for Real-Time Vehicle Dynamics Simulations

This paper discusses the development of a deformable terrain database to be used in a co-simulation environment with a multibody dynamics vehicle model. The implementation of the model includes a general tire-terrain traction model which is modular to allow for any type of tire model that supports the Standard Tire Interface[1] to operate on the terrain. Rather than utilizing empirical terramechanics models that only consider the pressure/sinkage directly under the tire, the governing equations of the terrain are based on a soil compaction model that includes both the propagation of subsoil stresses due to vehicular loads, and the resulting visco-elastic-plastic stress/strain on the affected soil volume. Pedo transfer functions allow for the calculation of the soil mechanics model parameters from existing soil measurements. This terrain model was implemented in a way that maps well to Graphics Processor Unit, which allows the model to run in realtime, enabling operator in the loop full vehicle simulations. Test simulations are run using a rigid tire with lugs to show the capability of the model to predict tire and terrain responses. Run times and scaling analyses are presented to gauge the relative speedup of utilizing GPUs for computational acceleration.