A comprehensive tune of coupled roll and lateral dynamics and parameter sensitivity study for a vehicle fitted with hydraulically interconnected suspension system

Abstract

Roll and lateral dynamics of a vehicle are heavily coupled together, the increase of roll stability does not necessarily result in the improvement of stability in the lateral plane, but the decrease in lateral stability possibly contributes to instability in the roll plane. To address this challenge, a comprehensive tune of coupled roll and lateral dynamics for a vehicle fitted with hydraulically interconnected suspension system is presented in this paper. A typical sport utility vehicle is selected and modeled with 10 degrees of freedom to conduct the dynamic simulation. Also, the fluid equations of the proposed hydraulically interconnected suspension system with nonlinear damper model are derived and incorporated into the vehicle model. Furthermore, the integrated model is validated by the field test. The simulation is also conducted to assess and compare the vehicle roll and lateral dynamic performances under fishhook maneuver. The results show that the well-tuned hydraulically interconnected suspension can suppress its body motion in roll plane, enhance the yaw rate tracking ability, minimize the sideslip angle at the center of gravity, and also decrease the slip angles for tires. Last, the parameter sensitivity analysis for a strongly nonlinear hydraulically interconnected suspension system illustrates how individual hydraulically interconnected suspension parameters (roll stiffness, roll stiffness nonlinearity, roll stiffness distribution ratio, and damping ratio) contribute to different dynamic aspects of a vehicle. The results indicate that, by controlling hydraulically interconnected suspension key parameters, the vehicle dynamic performance can be effectively controlled in both roll and lateral planes. The parameter sensitivity analysis findings have pointed out the direction for controller design and laid the foundation for active hydraulically interconnected suspension system development in the future.