Abstract
This paper shows that the VSS observer has the possibility to estimate adhesion force using wheel slip simulation and wheel slip experiments. The brake systems of railway vehicles possess strong nonlinear characteristics with variable parameters, such as adhesion force and friction coefficient of brake materials. It is important that the estimation method has robustness against such disturbance and parameter changes, and it is known that the Variable Structure System (VSS) observer has robustness against parameter change, disturbance input and so on. However, there have been no research reports about Variable Structure System (VSS) observer for the brake system or wheel slip preventing methods in railway. Simulation results show that the VSS observer can estimate the adhesion force efficiently. Moreover, it was performed the estimation experiments of adhesion force using VSS observer, and it has been clarified that the VSS observer can efficiently estimate the tangential force coefficient from the experimental results.
