Özbay, Hitay2022-02-172022-02-172021-07-162405-8963http://hdl.handle.net/11693/77477In this brief paper, controller design for delay margin optimization is considered for systems with internal feedback delays (systems with delays in the state variables). Similar to existing results on delay margin optimization for finite dimensional systems with I/O delays, it is shown that the problem considered can be solved by using Nevanlinna-Pick interpolation involving non-minimum phase zeros of the plant.EnglishLinear systemsRobust controlTime delay systemsStability marginsInterpolationArticle10.1016/j.ifacol.2021.06.176