Nonlinear observer for simultaneous states and unknown parameter estimation

Abstract

This paper presents the design of an observer for the simultaneous estimation of states and unknown parameter for a class of nonlinear systems whose nonlinearity satisfies a bounded Jacobian condition. The paper presents two alternate observers based on the structure of the system. The conditions for the existence of these observers can be expressed as a linear matrix inequality and solved using standard solvers. The case of time-varying parameter and multiple unknown parameter have also been investigated. The use of the developed methodology is demonstrated through illustrative examples.

Keywords:

• nonlinear observer
• parameter estimation
• LMI

Acknowledgements

The author would like to thank the anonymous reviewers for their comments and suggestions that have greatly helped to improve this paper.