A Nonlinear Six Degree-of-Freedom Axle and Body Combination Roll Model for Heavy Trucks’ Directional Stability

Abstract

Six degrees of freedom nonlinear suspension roll model of a heavy truck axle unit is presented. The model includes the effects of nonlinear tire damping, road inclination angle, and variation of suspension angles. The roll model parametric analysis provides the influence of various geometric truck parameters that are important to the designer in stability viewpoint. Many of the important parameters such as nonlinear tire coefficients, road and suspension inclination angles, and some of their limiting values for stability are also discussed to facilitate the selection of proper actuators and sensors for automation. The dynamic stability of the axle unit is illustrated using parameters dependent phase portraits. These phase portraits provide qualitative information on truck’s directional stability.