Analysis and design of robust estimation filter for a class of continuous-time nonlinear systems

Abstract

This article addresses the design of a multiconstrained robust estimation filter (MREF) for a class of continuous-time nonlinear systems in the presence of input and output disturbances. By constructing an augmented system, the MREF achieves the estimation of both states and faults, under existence conditions that are less restrictive than those associated with existing adaptive fault diagnosis observer (AFDO) and sliding mode observer design. Moreover, a detailed discussion on and comparison with the AFDO design are given. Furthermore, by introducing slack variables, improved results on MREF design are obtained such that different Lyapunov functions can be separately designed for multiple constraints. Simulation results are presented to illustrate our contributions.

Keywords:

• fault diagnosis
• fault estimation
• exponential stability
• continuous-time systems

Acknowledgements

The authors thank the Associate Editor and the reviewers for their comments and suggestions which have helped us to improve the presentation of this article. This work is partially supported by the National Natural Science Foundation of China (61034005), the key project of Natural Science Foundation of Jiangsu Province (BK2010072), the NUAA Research Funding (NZ2010003) and the Graduate Research and Innovation Project of Jiangsu Province (CX08B_090Z).