The leaf spring suspension - still widely applied in commercial vehicles - does not offer an optimum with regard to suspension performance. Due to the possibility of the levelling adjustment, the careful cargo treatment and the better ride comfort, the air suspension is, therefore, more and more succeeding.
To meet the requirements of higher performance of air suspensions in a cost favourable way and to to take full benefit of the potential of air suspensions, an electronically controlled air suspension system (ECAS) for trucks and buses has been developed and introduced into the market.
The functions of the entire system, its components as well as the advantages of the ECAS are described in comparison to the conventionally controlled air suspension systems.
Moreover, the system is extended to a semi-active suspension control, i. e. the integration of the damping control into the air suspension control. The result is a further improvement of the ride properties.