Modeling and System Identification of a Wheel-Soil System

In this paper a model of the wheel-soil system and its identification are presented. The model assumes the interaction between a wheel and soil can be described by the soil stress state under wheel loads. The stress state can be defined by means of the major stresses and their direction cosines, as well as the stresses in the octahedral stress system. Based on the soil stress analysis, traction forces in the wheel-soil system can be obtained by integrating the stresses. Identification of the model was performed using a 5T 4×4military truck, which was driven over three different soil surfaces and over a snow surface. For the identification of the model, values of drawbar pull force as well as soil stresses and deformation were required and they were measured in field experiments.