Two novel approaches of UIF design for T-S fuzzy system

This paper researches the state estimation problem for a class of T-S fuzzy system which subject to unknown input. For this set of system, two approaches are studied to design the UIF. A converted system is constructed in the first method to solve the insolubility problem of inequalities because of the existence of the unknown input. The second method establishes filter structure and achieves the purpose of estimating the system states through adopting the direct way. By employing unknown input filter, the paper makes a smooth estimation not only to the system states, but also to the estimate signals and unknown disturbance inputs. At last, a simulation example is used to illustrate the effectiveness of the proposed UIF.