A New Semi-Active Suspension System for Vehicle Applications

The goal of this study is two fold, one is to introduce a novel double damper based semi active suspension design and the other is to demonstrate the application of dynamic tire model in development of suspension controllers. In this study, a novel double damper suspension is introduced to show that a simple design modification of suspension can further improve the performance of the semi active suspension. A dynamic tire model was developed using a rigid ring tire and a tandem elliptical cam design for the enveloping model. A Lyapunov based adaptive ride control algorithm using a quarter car vehicle model with single damper and double damper suspension is developed. An ideal Skyhook-Groundhook 2DOF suspension is used as the reference model. The tire model and active suspension controller are then integrated with a full vehicle model to perform ride analysis. Using RMS acceleration of sprung mass vertical, roll and pitch motions as ride performance metrics, ride performance of no control, fully active control of single damper suspension and semi active control of double damper suspension are performed. The simulation results demonstrated that the importance of considering tire enveloping and dynamic effects and the emulation of novel semi active suspension system as active suspension without bottoming of suspension or deterioration of road holding properties. This behavior results in reduced power consumption, complexity and cost while the system performs like a fully active suspension system.