Numerical comparison of steering geometries for robotic vehicles by modeling positioning error

This paper describes an analytical method for modeling the positioning error of a robotic vehicle and examines how the metric of this error can be used to compare the geometries of various steering configuration. Positioning error can be caused by many factors stemming from the robot’s hardware and software configurations and the interaction between the robot and its environment. A slip motion model that captures the effects of key factors that contribute to positioning error is presented. Robot kinematic models with and without slippage are reformulated and used to perform an in-depth assessment and characterization of positioning error. The method is applied to three characteristic advance and steering configurations: Ackermann, articulated, and explicitly steered. This analysis serves as a quantitative evaluation of the properties of the steering geometries for path tracking under identical slippage conditions. The method can also be used as a tool for comparing robot configurations to make trade-off decisions early in the design process, as it allows for derivation of predicted performance values of alternative steering geometries.