GOALI Collaborative Research: Analytical Modeling and Experimental Analysis of Tires under Uncertain Intrinsic and Operational Parameters

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

This project addresses challenging aspects in modeling complex nonlinear mechanical systems, such as terrain vehicles and pneumatic tires, in the context of their operating environment. Within the scope of this study we will develop an analytical and computational framework to efficiently model such systems in the presence of parametric and external uncertainty. Specifically, we will develop methods to accurately represent the operating environment and the vehicle-terrain interaction. Moreover, we will conduct experimental studies using high-end technology to analyze the physical phenomena at the tire-terrain contact, and to validate the modeling techniques developed. For realistic performance predictions multibody dynamic models must account for uncertainties resulting from poorly-known environment parameters and rapidly-changing forcing functions. This project will employ the polynomial chaos expansion to simulate multibody dynamic systems with parametric and external uncertainties. This method is applicable to highly nonlinear systems, is computationally efficient, and can handle large uncertainties. Off-road vehicles represent a rich test-bed for the theoretical and experimental work proposed. Their performance prediction requires accurate models of the vehicle, the tire, and the terrain, all of which are affected by uncertainties. This project will model the soil from the standpoint of its dynamic interaction with a running vehicle, and will develop stochastic models for hard-to-predict soil characteristics. We will also employ a multi-step stochastic technique to simulate a rough terrain profile which does not impose unrealistic assumptions, and can be seamlessly incorporated in the vehicle-operating environment model. Further, the study will investigate innovative analytical methods to develop computationally efficient off-road tire models. The theoretical and the computational tools developed will significantly advance the field of multibody dynamics beyond the current deterministic paradigm, and will enable the development of appropriate control strategies. These tools are not domain specific and can also be applied to autonomous vehicles, industrial manipulators, actuators, and human body modeling.