Lateral Stability and Improvement for a Prototype Pickup Truck Vehicle Using Multi-Body Dynamics Simulation Tools 2016-01-1628

Lateral Stability is an important attribute which must be accounted for in the pick-up truck segment vehicles. If designed in an improper way, undesirable effects such as oversteer or tail sway may occur. Excessive yaw rate magnitudes, or tail sway, can reduce the confidence of the driver during severe lane change events. The concept architecture of the vehicle plays an important role in how stable the vehicle will be.

High yaw rate or tail sway during limit cornering was reported during prototype vehicle evaluations. The tested vehicle configuration incorporated a double wish bone front suspension with an antiroll bar and a rear solid axle suspension with leaf springs and an antiroll bar. The feedback was critically analysed using computer simulations of the condition found in on track testing. Since the vehicle was still with the validation team, quick solution was necessary.

This paper discusses the process which resulted in improved vehicle performance. The modelling and analysis of the vehicle for lateral dynamics is discussed as is the correlation of the simulation results with real world test data.

The analysis of the influence of various parameters on the lateral dynamics using the MSC.ADAMS/CAR software is also presented. Simulations with different spring stiffnesses were carried out on the in-house existing suspension. Different antiroll bar configurations were studied for their effect on vehicle yaw stability thus avoiding new system development time and cost. The influence of the above parameters was studied using maneuvers which involved steady-state cornering as well as single lane change and double lance change tests. The results of the simulations indicated that the shock-absorber needed higher damping levels and the antiroll bars were increased in size in order to improve the dynamic performance of the pickup truck. The new suspension tuning level felt improved compared to the existing configuration.