Abstract
An analytical and numerical study of a multi-degree of freedom passenger car incorporating Passive, Active, and Semi-Active Suspension is performed. The model with data of a typical vehicle includes rigid body translational and rotational modes. This constitutes an extension of the state-of-the-art, since previous investigations of semiactive suspensions were restricted to heave and pitch mode control. The vibrations of the four-wheeled vehicle moving at constant forward speed are induced by random roughness of the left and right track.