Computationally Efficient Linear Elastokinematic Simulation of Double Wishbone Suspension for Early Vehicle Concept Development

Tires are the sole interface elements between the road and the vehicle. The wheel alignment and orientation with respect to the vehicle body and the road surface have a significant influence on the force transmission and thus on the safety and handling of the vehicle. The geometry and design of the wheel suspension, and therefore its kinematics, govern this alignment and orientation. Ideally, rigid suspension joints with zero-play and tight tolerances are desirable for stable and safe vehicle behavior. However, owing to manufacturing complexities and ride comfort requirements, elastomer bushings are used in the suspension joints, which results in compliance altering the wheel alignment under force application. Considering the elastokinematic behavior during the early concept development phases of the vehicle would provide more accurate and realistic predictions of suspension characteristics and vehicle dynamics. Conventional approaches typically use non-linear modelling techniques, which are complex and computationally intensive for simulating such suspension layouts. The paper proposes a computationally efficient linear modelling methodology for simulating the elastokinematic behavior of double wishbone front suspensions. This approach is based on a decoupled formulation, where the force equilibrium equations and wheel motion equations are solved separately to determine compliance-induced variations in wheel alignment. The proposed method has been implemented as an elastokinematic module to enhance an in-house developed suspension kinematics software. The methodology has been verified by comparing the results with Adams/Car Multi Body simulations (MBS) for various configurations of double wishbone front suspensions. Results demonstrated that the proposed linear approach achieves significantly reduced computation times while maintaining very good accuracy, enabling faster iterations and optimization cycles. This leads to shorter development cycles and contributes to achieving a higher maturity level of the suspension concept at the end of the concept development phase.