Observer-based robust H∞ control of a class of discrete time systems with state uncertainties

In this paper, it is shown that the observer-based robust H_infin control of a class of discrete-time systems with state uncertainties is conditioned by the solvability of a linear matrix inequality. We show that the observer-based robust H_infin control problem, which is originally a non-convex issue, can be transformed into a convex problems by using an particular inequality. The new proposed linear matrix inequality is neither iterative nor subject to any equality constraint. A flight control system example is given to indicate the feasibility of the proposed design approach.