On the states and parameters estimation of non-linear discrete-time systems. Design and experimental results

In this note, we propose a simple and useful decentralized approach for the states and parameters estimation of general nonlinear discrete-time MIMO systems. Thanks to a simple and useful parametrization technique, we investigate the stability analysis and it turns out that not only asymptotic convergence is assured under very general conditions but also how to enlarge the basin of attraction with high tracking ability. Performances and accuracy of the results are illustrated, first, through a simulation example under severe conditions. Next, the proposed technique will be successfully applied to a real single-link rigid manipulator using only the position measurements.