Improved stability analysis for discrete system with interval time-varying delay

In this paper, the problems of delay-dependent stability analysis for the discrete-time system with interval time-varying delay is considered. By using a new Lyapunov functional approach, sufficient conditions for the stability of the system can be obtained. By constructing appropriate free weighing matrices and utilizing the convexity of the matrix functional, we need not enlarge the time-varying delay to its upper bound, thus the conservativeness caused by the enlargement can be avoided. All the derived conditions are shown in terms of linear matrix inequalities, which can be easily solved by using the corresponding software. Two numerical examples are given to demonstrate the less conservativeness of the proposed method.