OBSERVABILITY ROBUSTNESS OF UNCERTAIN FUZZY-MODEL-BASED CONTROL SYSTEMS

The problem considered in this study is the observability robustness of Takagi -Sugeno (TS) fuzzy-model-based control systems. Where a nominal TS-fuzzy-model-based control system is locally observable (i.e., where each fuzzy rule in the system has a full row rank for its observability matrix), a sufficient condition is proposed to preserve the assumed property when system uncertainties are considered. The proposed sufficient condition preserves the assumed property by indicating the explicit relationships of bounds on system uncertainties. A robustly global observability condition is also presented for uncertain TS-fuzzy-model-based control systems. Finally, the proposed sufficient conditions are applied in the example of a nonlinear mass-spring-damper mechanical system with system uncertainties.