Comparative analysis of two non-linear observers for estimation of tyre/road contact in the presence of imperfect measurements

This study presents a comparative study of a sliding-mode observer-based scheme and an adaptive observer-based scheme designed to estimate a road surface condition parameter. The effect of imperfect measurements associated with the wheel angular velocity is explored. A detailed analytical analysis is presented and results are shown from a variety of simulations. Both schemes assume only wheel angular velocity is measured and use an observer to reconstruct the states and the road condition parameter.