SAE International Mobility and Energy Efficiency Analysis of a Terrain Truck 2013-01-0672

While much research has focused on improving terrain mobility, energy and fuel efficiency of terrain trucks, only a limited amount of investigation has gone into analysis of power distribution between the driving wheels. Distribution of power among the driving wheels has been shown to have a significant effect on vehicle operating characteristics for a given set of operating conditions and total power supplied to the wheels. Wheel power distribution is largely a function of the design of the driveline power dividing units (PDUs). In this paper, 6×6/6×4 terrain truck models are analyzed with the focus on various combinations of PDUs and suspension systems. While these models were found to have some common features, they demonstrate several different approaches to driveline system design. In order to further investigate the effect of wheel power split on mobility and energy/fuel efficiency in conjunction with suspension characteristics, this paper provides an analytical method and mathematical model for the entire truck, including driveline system (sets of PDUs), suspension, and tires under various typical operating conditions. Interactions between longitudinal and normal truck dynamics are first modeled and their influence on vehicle mobility and energy efficiency is analyzed. A computational algorithm is presented, which integrates equations for the driveline system with the suspension model (i.e., wheel normal reactions), along with a method for solving the integrated equations. Finally, an analysis of the effects of PDU combinations on truck mobility and energy efficiency is demonstrated.