Decentralized variable structure control of vehicle active suspensions

A design method for active suspension systems of vehicles is proposed based on the decentralized variable structure controller (DVSC) and a 7-degree-of-freedom full-car model. Its nominal stability and stability robustness to parameter variations are assured through stability analysis. The performance of the DVSC is compared with that of a LQR controller in computer simulations. From the simulations, it is found that active suspensions with the DVSC reduce the acceleration of the sprung mass in the heaving, rolling, and pitching directions when the car is driven on a normal road or through an asymmetric bump. The suspension stroke and road holding capability are also compared under the assumption of equal power consumption.