Sensitivity Analysis of Mobile Robots for Unstructured Environments

Abstract

Simulating mobile robots in unstructured environments requires knowledge of the wheel/terrain interaction phenomena. Even assuming that the terramechanics models available accurately represent the physics of the interaction, estimation of soil parameters can be a source of error. In applications where high robot reliability is mandatory, it is important to realize the influence of possible sources of error on the system behavior. The effect of small variations of parameters on system performance can be studied under sensitivity analysis. In this work, sensitivity analysis is conducted to investigate the effect of perturbations in the soil parameters on the behavior of a single rigid wheel and a vehicle on soft terrain. For the first system the two widely used terramechanics models, Bekker’s and Wong and Reace’s are studied, sensitivity analysis being conducted using direct differentiation. The second system is modeled using Bekker model, sensitivity being obtained using finite differences.