Enhanced 3D Kinematic Modeling of Wheeled Mobile Robots

Most fielded wheeled mobile robots (WMRs) today use basic 2D kinematic motion models in their planning, control, and estimation systems. On uneven or low traction terrain, or during aggressive maneuvers, higher fidelity models are required which account for suspension articulations, wheel slip, and liftoff. In this paper we present a simple, algorithmic method to construct 3D kinematic models for any WMR configuration. We also present a novel enhancement to predict the effects of slip on bodylevel motion. Extensive experimental results are presented to validate our model formulation. We show odometry improvement by calibrating to data logs and modeling 3D articulations. We also show comparable predictive accuracy of our enhanced kinematic model to a full dynamic model, at much lower computational cost.