Performance prediction of a wheeled vehicle on unknown terrain using identified soil parameters

This paper presents a novel technique for identifying soil parameters for a wheeled vehicle travelling on an unknown terrain. The identified soil parameters are required for predicting vehicle drawbar pull and wheel drive torque which can be employed for traversability prediction, traction control, and performance optimization of a wheeled vehicle on unknown terrain. The Newton Raphson method is used as the identification technique applied on the modified form of the wheel-soil interaction dynamics model using the Composite Simpson's Rule. This work focuses on identifying the internal friction angle, the shear deformation modulus, and the lumped pressure-sinkage coefficient. The fourth parameter, cohesion, does not influence the vehicle drawbar pull and is assigned an average value during the identification process. In an experimental study, the identified parameters are compared with known values, and shown to be in good agreement. Soil parameter identification can be carried out on-line and thus our approach is suitable for real-time applications. The robustness of the method is also shown to be relatively good. The identified soil parameters can be used to predict drawbar pull and wheel drive torque with good accuracy.