Abstract
In this paper the relation between semi-active suspension characteristics and vertical oscillations of the vehicle body on road roughness is analysed. During experimental tests, the damping of semi-active suspension was changed while measuring vehicle's sprung and unsprung mass vertical accelerations, pitch rate, which were transformed into a frequency domain for further analysis. The results of the experimental tests were compared to the simulations using the semi-active dynamic model. Validation has shown that model can be used to analyse the influence of semi-active suspension parameters on vehicle oscillations over the entire range of semiactive suspension settings. The comparison of experimental and theoretical simulation showed that semi-active suspension settings have influence on longitudinal oscillations of the sprung mass and it should be estimated in related researches of modern suspension.