Real-time Damper Force Estimation of Vehicle Electrorheological Suspension: A NonLinear Parameter Varying Approach

Abstract

Abstract This paper proposes a nonlinear parameter varying (NLPV) observer to estimate in real-time the damper force of an electrorheological (ER) damper in road vehicle suspension system. First, a nonlinear quarter-car model equipped with the dynamic nonlinear model of ER damper is presented, which captures the main behavior of the suspension system. The estimation method of the damper force is developed using a NLPV observer whose objectives are to minimize the effects of bounded unknown road profile disturbances and measurement noises on the estimation errors in the H∞ framework. Furthermore, the nonlinearity coming from damper model (and considered in the observer formulation) is handled through a Lipschitz condition. The observer inputs are given by two low-cost sensors data (two accelerometers data from the sprung mass and the unsprung mass). For performance assessment, the observer is implemented on the INOVE testbench of GIPSA-lab (1/5-scaled real vehicle). Both simulation and experimental results demonstrate the effectiveness of the proposed observer in terms of the ability of estimating the damper force in real-time and of minimizing the effects of measurement noises and road disturbances.