Behzad Golanbari - Department of Mechanical Engineering of Biosystems, Urmia University, Urmia, Iran.
Aref Mardani - Department of Mechanical Engineering of Biosystems, Urmia University, Urmia, Iran.

Three parameters of soil, vertical load and tire play a role in determining vehicle traction force in the process of soil and tire interaction.  The complexity of the situation and the variability of variables such as the soil-tire contact area and contact pressure make it difficult to develop traction force estimation models. In this study, the first step involved developing a traction force prediction model under the assumption of a variable contact area and contact pressure, and developing a mathematical model to predict off-road vehicle traction force. The obtained model includes seven parameters related to tire, load, soil and tire dynamics of wheel movement, which are vertical load, soil-tire contact length, tire width, slip, soil cohesion, soil shear deformation parameter and angle of internal shear resistance. A statistical population with five levels for each of its component parameters was created to study the impact of those parameters. The Taguchi method was used to examine the relationship between parameters and traction force. The Taguchi method is employed to determination the key factors that significantly impact a process, also it employs a systematic experimental design, to minimize the number of experiments needed. The results confirmed that all seven parameters had a significant impact on the amount of traction force and established the relative importance of their effects on one another. As a result, the tire width and slip parameters played the most and the least roles in improving traction force, respectively.

Terramechanics, Analytical model, Traction force, Soil stress, Soil-tire interaction, Contact area