Interval estimation of switched Takagi-Sugeno systems with unmeasurable premise variables. Issue 11 (2019)

• Record Type: Journal Article
• Authors: Garbouj, Yosr; Dinh, Thach Ngoc; Zouari, Talel; Ksouri, Moufida; Raïssi, Tarek
• Is Part Of: IFAC-PapersOnLine. Volume 52:Issue 11(2019)
• Page Start: 73
• Page End: 78
• Publication Date: 2019
• Subjects: Nonlinear switched system -- Takagi-Sugeno models -- unmeasurable premise variables -- stability -- robustness -- interval observer design; Automatic control -- Periodicals; 629.805
• DOI: 10.1016/j.ifacol.2019.09.120
• Languages: English
• ISSNs: 2405-8963

Abstract

Abstract: This paper deals with interval observers design for nonlinear switched systems. The nonlinear modes are represented by the Takagi-Sugeno (T-S) fuzzy models with premise variables depending on unmeasurable terms, e.g. the state vector. This T-S structure can be used to represent exactly a nonlinear switched system in a compact set of the state space. The introduced method in this paper allows to compute the lower and upper bounds of the system state under the assumption that the disturbances as well as the measurement noises are unknown but bounded. First, the stability conditions of the proposed T-S interval observers are developed via Linear Matrix Inequality (LMI) formulations to ensure the convergence of the nonnegative observation error dynamics. Then, changes of coordinates are employed to relax the restrictive requirement of nonnegativity constraints. Theoretical results are applied to a numerical example to illustrate the effectiveness of the proposed method.