Active Reconfiguration for Performance Enhancement in Articulated Wheeled Vehicles

Leg-wheel architectures for locomotion systems offer many advantages, not the least of which is reconfigurability of wheel-axle with respect to the chassis. Thus, locomotion systems with multiple leg-wheels now permit enormous reconfigurability of the chassis frame with respect to the ground frame. We seek to systematically exploit this ability to reconfigure within this highly-redundant system to enhance contact kinematics i.e., reducing the slippage and improving traction forces at wheel-ground interfaces. In addition, reconfiguration can also be used to mitigate undesirable system-level effects (such as judder) and lead to greatly improved estimation for navigation. In this paper, we examine a systematic analytical approach to the modeling, analysis and reconfiguration of articulated leg-wheel systems, to enhance both traction as well as stability-margin, while navigating over rough-terrains. The derivations will also be specialized to a particular example of an ultra-mobile actively-articulated vehicle to illustrate the developed procedure.