Virtual Reality Simulation of Vehicles and Tools Interacting with Deformable Terrain

Realistic physics-based simulation of vehicles on soft terrain has increasingly gained importance due to their broad application from operator training to mission planning and design. In this work we combine models from terramechanics and soil mechanics to represent the interaction of vehicles and their tools with a deformable terrain, allowing us to simulate a broad range of vehicles, including earth moving equipment and planetary rovers on soft ground in real time. We consider the impact of both wheel–ground and tool–ground interactions on the vehicle behavior by creating a fully coupled simulation of the dynamics of the vehicle and its environment. Soil exhibits a multitude of different behaviors depending on material properties, soil formations and interactions with the medium, including erosion and compaction. Non-linear stress–strain relationships as well as highly plastic material deformation and flow makes simulation of soil a challenging task. In addition, the demands of real-time simulator environments are rather high concerning both realistic visualization and physical correctness, since for training purposes real life scenarios have to be displayed with sufficient accuracy to prevent negative training. Therefore, in Virtual Reality (VR) training simulators for bulldozers, excavators but also planetary rovers a balance has to be found between interactivity and physical correctness of soil behavior. In this paper, we present one such solution. In simulation studies we show how the vehicle’s behavior (e.g., its trajectory and mobility) is impacted when it is operated over areas already modified by its tool or wheels.