One of the roots of vehicle vibrations and shakes is the road roughness. Shocks due to bumps on the road are transferred to the vehicle body through the wheels and not only make discomfort for passengers but also reduce the quality of driving. In this paper, a vehicle suspension system will be designed. Then its performance will be shown through analysis and simulation. The main idea is based on the combination of a nonlinear energy sink and a skyhook. The performance of the proposed suspension system will be evaluated by comparing car body vertical accelerations and suspension deflections with a passive suspension system. The sliding mode control as a robust nonlinear control method has been used to make the system robust to changes and uncertainties in car model. The Lyapunov based stability analysis shows that the tracking error of proposed system will asymptotically approach zero.
