Observability and State Estimation for a Class of Nonlinear Systems

TL;DR

This paper establishes conditions under which the state of certain nonlinear, time-varying systems can be estimated accurately, introducing a sequence of functionals and hybrid observers for improved estimation.

Contribution

It provides new sufficient conditions for state estimation in nonlinear systems with triangular structure, including the development of a sequence of functionals and hybrid observers.

Findings

Derived sufficient conditions for state estimation solvability

Introduced a sequence of functionals for approximating states

Demonstrated the effectiveness of hybrid observers

Abstract

We derive sufficient conditions for the solvability of the state estimation problem for a class of nonlinear control time-varying systems which includes those, whose dynamics have triangular structure. The state estimation is exhibited by means of a sequence of functionals approximating the unknown state of the system on a given bounded time interval. More assumptions guarantee solvability of the state estimation problem by means of a hybrid observer.