Real-time multibody vehicle model with bush compliance effect using quasi-static analysis for HILS

Abstract

Vehicle handling simulations such as J-turns, slaloms, double lane changes, and fish hook maneuvering are essential to evaluate the control subsystems of the intelligent vehicle in the HILS (Hardware-in-the loop simulation). It is well known that the compliance effects from bushes in the suspension subsystem are important to have reliable solutions for the handling simulations. In the multibody vehicle dynamics model, the bush elements in the suspension subsystem are usually modeled as high-stiffness springs. However, due to this high stiffness of the bush model, it requires small step-sizes in the numerical integration. With this kind of bush model, it is almost impossible to achieve real-time simulations for HILS. In this paper, a quasi-static analysis method is presented in order to consider bush compliance effects for a real-time multibody vehicle model. To validate the proposed method, the quarter car simulations of the McPherson strut and the Multilink suspension subsystems have been performed, comparing with the ADAMS simulations. Full car bump run simulations and fish hook handling test simulations have also been carried out to see the effectiveness of the proposed model. The CPU time measured shows the real-time capabilities of the proposed method.