A relaxed solution to unknown input observers for state and fault estimation

Patton, Ron J.; Tan, Daoliang; Wang, Xi

Abstract

A lot of effort has been devoted to the unknown input observer (UIO) research over the past years. However, the strong disturbance decoupling assumption (manifested as some rank constraint) is often implicitly embedded in much of the existing UIO work. With the purpose of state and fault estimation, this fact motivates us to investigate the viability of the UIO research when the strong disturbance decoupling is not possible, i.e., a “degenerate” problem of UIO decoupling exists. Inspired by the scheme of reducing the effect of external disturbance on estimation error, this paper incorporates the relaxed UIO (RxUIO) concept by means of the H∞H2, and mixed H2¡H∞ techniques. Necessary and sufficient conditions for the existence of different RxUIOs are presented in the tractable linear matrix inequality (LMI) form. Numerical experiments are presented to illustrate the effectiveness of the suggested method.

• Journal Article Type: Article
• Publication Date: Sep 1, 2015
• Journal: IFAC-PapersOnLine
• Print ISSN: 1474-6670
• Electronic ISSN: 2405-8963
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 21
• Pages: 1048-1053
• APA6 Citation: Tan, D., Patton, R. J., & Wang, X. (2015). A relaxed solution to unknown input observers for state and fault estimation. IFAC postprint volumes IPPV / International Federation of Automatic Control, 28(21), 1048-1053. https://doi.org/10.1016/j.ifacol.2015.09.665
• DOI: https://doi.org/10.1016/j.ifacol.2015.09.665
• Keywords: Fault diagnosis, Fault estimation, Unknown input observer, Linear matrix inequality
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S2405896315017942
• Copyright Statement: © 2016 IFAC. Originally published in IFAC-PapersOnline, vol. 48, no. 21 by Elsevier Ltd. (DOI 10.1016/j.ifacol.2015.09.665)
• Additional Information: This is an authors accepted manuscript version of a paper published in IFAC-PapersOnLine, 2015, v.48 issue 21.