Real-Time Flexible Multibody Simulation of a Vehicle Wheel Suspension with Elastokinematic Properties Based on Inertia Relief Modes

The vehicle wheel suspension is a complex mechanism that guides the wheels and transmits wheel forces. In addition to its kinematic design, wheel position changes also occur due to its compliance. This elastokinematics is caused by elastic bushings but also by the flexibility of the suspension bodies. As they affect the vehicle’s driving behavior, multibody simulation models should accurately represent these properties. In addition, real-time capability is desired due to the increasing importance of driving simulators in the vehicle development process. This paper demonstrates the real-time flexible multibody simulation of a vehicle wheel suspension with elastic bushings and body flexibility. Flexible bodies are modeled with the floating frame of reference approach incorporating inertia relief modes. The numerically stiff equation of motion is integrated with a linear-implicit integration scheme. Through a sensitivity analysis, a reduced mode set of in total 26 important modes was identified. With that, it is possible to simulate the suspension in real-time covering most of the influence of the body flexibility.