On the Optimal Ride Control of a Dynamic Model for an Automotive Vehicle System

SUMMARY 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 semi-active suspensions were restricted to heave and pitch mode control (exclusive of roll). The vibrations of the four-wheeled vehicle moving at constant forward speed are induced by random roughness of the left and right track. The influence of active and semi-active damping on vehicle ride quality control is determined, and compared with the conventional passive suspension by means of a computer simulation. Simulation results in the time and frequency domain show that the semi-active damper is superior than the conventional passive one, with performance approaching that of a fully active system. The penalty cost associated with these ride comfort improvements is an increase of the secondary and primary suspensions deflections.