Full vertical car observer design methodology for suspension control applications

This paper deals with the design of an H∞-observer to estimate the state variables of the vertical car dynamics to be used for suspension control applications. The proposed methodology allows to cope with both the disturbance decoupling problem (for the road profile effects) and the implementation issue (through observer pole placement). The considered model is a 7 DOF full-car vertical model subject to unknown ground disturbances whose effects on the estimated state variables are minimized using the H∞ framework. Some experiments on a real test car highlight the performances of this observer which could be used in many advanced control strategies to improve the comfort and road holding of a vehicle using a reduced number of sensors.