Rejection of persistent-bounded disturbances in linear time-delay systems by output-feedback

In this paper, the problem of persistent-bounded disturbance rejection of linear continuous-time systems with time-varying delays is investigated using the tools of invariant set analysis and Lyapunov-function methodology. We derive less conservative sufficient conditions on robust attractor for time-delay systems in terms of strict linear matrix inequalities (LMIs) to guarantee the desired L₁-performance. A robust output-feedback controller is designed and the associated gain is determined using strict LMIs. The developed results are tested on two representative time-delay examples.