Analysis of the lateral dynamic behaviour of articulated commercial vehicles

The challenge of designing stability control functions for trucks is to guarantee robustness for all variations in truck and trailer combinations. The method proposed in this study can be used to quickly narrow down the number of truck and trailer combinations to a critical set to be evaluated with complex nonlinear simulation software or full-scale tests. To reach this goal, equations of motion are derived for single track linear vehicle models to understand the fundamental differences between the dynamic yaw performance of the truck and trailer combinations. The Hurwitz criterion is used to determine approximate analytical stability boundaries. It is shown that stability does not provide discrimination between combinations as most combinations are stable during normal driving conditions. In contrast, rearward amplification is a discriminatory performance measure. A frequency domain approach is used to study the fundamental differences between vehicle combinations. A comparison with complex nonlinear simulation model results indicates that the proposed method can be used to select critical vehicle combinations and to study the effect of parameter changes