Observer design for nonlinear systems with delayed nonlinear output measurement
Résumé
This paper deals with nonlinear observer design for systems with delayed nonlinear outputs. The main idea behind this work consists of using a dynamic extension technique to transform a system with delayed nonlinear outputs into a system with linear outputs and a delay-dependent integral term in the dynamic process. First, a general result for arbitrary nonlinear structure is proposed, and then further contributions are provided for specific families of systems, namely systems in companion form and feedforward systems. For systems in companion form, we obtain novel high-gain observer synthesis conditions, while new low-gain results are obtained in the case of feedforward systems. To relax the necessary conditions related to the observer design procedure, a different state observer structure is proposed and comparisons are provided.