Output feedback H∞ control of sampled-data systems with parametric uncertainties

This paper investigates the problem of output feedback robust H_infin controller design for sampled-data systems with time-varying norm-bounded parameter uncertainties in the state matrix and input matrix. Attention is focused on the design of a causal output feedback sampled-data controller which guarantees the asymptotical stability of the closed-loop system and reduces the effect of the disturbance input on the controlled output to a prescribed H_infin performance bound gamma for all admissible parametric uncertainties. Sufficient condition for the solvability of the problem is in terms of linear matrix inequalities (LMIs). It is shown that the desired output feedback H_infin controller can be constructed by solving certain LMIs. An illustrative example is given to demonstrate the effectiveness of the proposed method.