An improved H∞ filter design for systems with time-varying interval delay

This brief is concerned with H-infinity filter design for systems with time-varying interval delay (i.e., the time delay is varying in an interval). An appropriate type of Lyapunov functionals is proposed to investigate the delay-dependent H-infinity filter design problem. Improved delay-dependent results are presented by taking into account the interval range. Finally, a numerical example is given to demonstrate the effectiveness and the benefits of the proposed method.