Unknown Input Method Based Observer Synthesis for a Discrete Time Uncertain T–S Fuzzy System

In this paper, we propose a novel approach based on an unknown input method to synthesize the observer for a discrete time uncertain Takagi-Sugeno fuzzy system. The uncertainty bounds of the system can be unknown and the premise variables can be measurable or unmeasurable. Two main theorems are derived based on the noncommon quadratic Lyapunov function and feasible parameters are solved by the linear matrix inequality technique. Finally, a practical example is given to prove the effectiveness of the proposed method.