H∞ Unknown Input Observer Design Based on LMI

Abstract:

The original discrete time Lipschitz nonlinear system with measurement noise and unknown input is transformed into an augmented descriptor system without measurement noise by taking measurement noise vector as an extended state vector. An H∞ unknown input observer which can estimate the state and the measurement noise of original system is developed, and the existence of the observer depends on the solution of the feasible solutions of linear matrix inequality (LMI). Then, an algebraic unknown input reconstruction method is proposed based on the delay estimation approach. The result of a simulation example is given to illustrate the effectiveness and correctness of the proposed method.