Flat control of a torsion bar with unknown input estimation

The main purpose of this paper is to design a flat control of a real torsion bar system subject to unknown input variables using the concept of unknown input observer. The bond graph approach is used due to its structural and causal properties. Three main points are developed: modeling of the dynamical system with model simplification using an integrated approach, application of an unknown input observer with estimation of physical variables and application of a flat control on the experimental system.