Improved delay-dependent H∞ control for linear systems with interval time-varying delay

In this paper, we investigate the problem of H_∞ control for linear systems with interval time-varying delay. We divide the delay intervals into several subintervals and construct the corresponding Lyapunov-Krasovskii functional. Based on Lyapunov stability theory and free weighting matrix method, the H_∞ control problem is solved and the H_∞ controller gain can be obtained by solving linear matrix inequalities (LMIs) for given parameters. The parameters´ optimal value can be obtained by using simplex method. Finally, numerical examples are given to illustrate the effectiveness and less conservativeness of the proposed method.