Online identification of road profile variation using a constant piecewise function

Abstract

Road profile estimation has become an indispensable tool for improved route planning and enhanced design of active suspensions. Performances requirements, such as increasing ride comfort and improving the driving maneuverability, depend on the road unevenness. The core idea is to use vehicle dynamics to get information about road perturbation and isolates passengers from vibrations. Online estimation of geometric variation of the road was investigated in this paper based on the operational calculus method and algebraic approach. The estimator equations are derived from a predictor scheme which was used to approximate this unknown signal variation by a piecewise constant function. The major interest of this technique is that it allows using minimum numbers of mechanical sensors and few parameters for tuning. Accurate approximations were obtained from the measurement of sprung mass and un-sprung mass vertical displacements. Numerical results with MATLAB/Simulink environment were used for investigating the effectiveness of the proposed technique for fast prediction.