Disturbance observer based sliding mode control of active suspension systems

In this paper, a novel scheme to reduce the acceleration of the sprung mass, used in combination with sliding mode control, is proposed. The proposed scheme estimates the effects of the uncertain, nonlinear spring and damper, load variation and the unknown road disturbance. The controller needs the states of sprung mass only, obviating the need to measure the states of the unsprung mass. The ultimate boundedness of the overall suspension system is proved. The efficacy of the method is verified through simulations for three different types of road profiles and load variation and the scheme is validated on an experimental setup. The results are compared with passive suspension system.