<div class="section abstract"><div class="htmlview paragraph">The road condition has an important influence on ride quality; however, the road condition cannot be sufficiently controlled. The proper design of truck components is the only way to improve ride quality. This work is an investigation into the ride behaviour of passive and active suspension systems using full truck model. A mathematical model for the evaluation of ride comfort for a truck moving on an irregular road surface is developed. The cab suspension for passive system is represented by a parallel arrangement of a spring and damper. The gain scheduling (GS) strategy is used to improve truck ride comfort. The influence of suspension elements, tyre stiffness, truck speed and road input on ride comfort is evaluated. The results showed that the active suspension system with gain scheduling strategy gives better ride improvements compared with active system .in terms of vertical cab acceleration. Furthermore, the optimum values of cab spring stiffness and damping coefficient are obtained.</div></div>