Estimation of the semi-active damping force by using an H2 observer

Abstract

In this article, the author presents the way to estimate the value of the semi-active electro-rheological (ER) damping force used for semi-active suspension system on cars. First, a quarter car model is combined with the dynamical model of the ER damper. In which the damping force of the ER damper is
a variable of the state vector in the general state-space representation. An H2 observer is then designed to estimate the damping force value by minimizing the impact of the road profile and sensor measurement noises on the error of the variables in the state vector (between the actual signal and the estimated value). Simulation results in both frequency and time domains by Matlab/Simulink software through four different types of road profile have demonstrated the effectiveness of the design observer in estimating the value of the damping force.