ROSTDyn: Rover simulation based on terramechanics and dynamics

• Based on Vortex, a terrain model is developed for ROSTDyn.
• We propose a method to compute contact-area parameters.
• We develop contact force/torque model combined with Vortex.
• ROSTDyn can perform a real-time simulation.
• Contrast of simulation and experiment verifies a good fidelity of ROSTDyn.

In recent years, rover-based planetary exploration missions have induced some new challenges related to both the speed and the fidelity of rover simulation. This paper introduces ROSTDyn (rover simulation based on terramechanics and dynamics), a good-fidelity (in a linear motion without side forces and related torques), real-time (with an Intel Core2 CPU and ATI Radeon HD 4650 GPU) simulation platform for planetary rovers developed using C++ on the basis of the Vortex physics engine. The inherent trade-off between high fidelity and high speed is overcome by using an improved and simplified terramechanics model and Vortex. This paper presents the key technologies and algorithms constituting ROSTDyn, including the creation of the rover model and terrain model, computation of contact-area parameters, computation of interactive force/torque model, and ROSTDyn’s implementation. Speed tests confirm that ROSTDyn can perform a real-time simulation when the display frequency is less than 45 Hz and the computation frequency is less than 450 Hz. A comparison of the simulation and experiment results for an example involving a six-wheel rover climbing a series of slopes confirms the good fidelity of ROSTDyn.