Experimental results of an ∞-observer for an industrial semi-active suspension

In this paper, an H∞-observer to be used in suspension control application is addressed to estimate a quarter car model equipped with an industrial SOBEN damper, using a reduced number of sensors. Vehicle estimation is one the main challenges in suspension control since many control strategies developped in past studies use variables that are nonmeasurable in practice. This observer is designed in the H∞ framework in order to minimize the effect of the unknown road disturbance on the estimated states and uses a single, cheap and reliable acceleration sensor mounted on the unsprung mass. The estimated variables are the vertical velocities and positions of the sprung and unsprung masses of the quarter car. Some experiments done on a testing car highlight the performances of the observer. This observer could be used in a suspension control application in order to reduce the number of sensors and the cost of the control system.