Performance Indicators for Wheeled Robots Traversing Obstacles

Abstract

An important element of wheeled robot operations on uneven and unstructured terrain is the ability to overcome obstacles. In this letter, we deal with a part of this obstacle negotiation problem. We particularly investigate the ability of a wheeled robot, originating from its mechanical design, to successfully negotiate an obstacle. The work reported primarily investigates how the mechanism topologies and the resulting mass and inertia distributions influence obstacle negotiation. The kinematics of the obstacle and ground contact is described using the variables that represent the degrees of freedom of the articulated mechanical system of the robot; this enables the study of the effect of the robot topology on the contact dynamics. Based on this we develop a dynamics formulation that allows us to propose performance indicators to characterize the ability of the wheeled robot to overcome obstacles. This formulation accounts for the unilateral nature of interaction between robot, obstacle, and ground. We illustrate the work with simulation and experimental results.