Observer design for triangular systems under weak observability assumptions

TL;DR

This paper develops observer design methods for nonlinear triangular systems with inputs, using delayed and switching observers to achieve local and global state estimation under weak observability conditions.

Contribution

It introduces a novel observer design approach combining delayed Luenberger-type systems and switching strategies for nonlinear triangular systems.

Findings

Local state estimation achieved with delayed Luenberger observers

Global estimation via a switching sequence of observers

Works under weak observability assumptions

Abstract

This paper presents results on the solvability of the observer design problem for general nonlinear triangular systems with inputs, under weak observability assumptions. The local state estimation is exhibited by means of a delayed time-varying Luenberger-type system. In order to achieve the global estimation, a switching sequence of observers is designed.