A new approach to design fuzzy interval observer for parameter-varying systems

Interval observers are attractive tools, particularly for parameter-varying and uncertain systems. This paper presents a new fuzzy interval observer design for estimating the lower and upper bounds of the state variables for the parameter-varying systems. The interval observer design requires to satisfy monotone property for the lower and upper bounds of the error. In this regard, some new conditions are defined for the membership functions as well as the Metzler property of the state matrix to ensure that the state variables are surrounded by their bounds. The numerical simulations indicate that the proposed method provides satisfactory performance.