Modeling wheeled locomotion in granular media using 3D-RFT and sand deformation

Modeling the wheel-soil interaction of small-wheeled robots in granular media is important for robot design and control. A wide range of applications, from earthmoving for construction and farming vehicles to navigating rough terrain for Mars rovers, motivate the need for a model that can predict the force response of a wheel and the terrain shape afterward. More importantly, the speed, accuracy, and generality of the model should be considered for real-world applications. In this paper, we offer a straightforward sand deformation simulator to simulate the soil surface and integrate it with 3D-RFT in order to capture the soil motion caused by the wheel. The proposed method is able to: (1) estimate three-dimensional interaction forces of arbitrarily shaped wheels traveling in granular media; (2) simulate the soil displacement from the trajectory; and (3) perform the force calculation in real-time at 60 Hz.