Tan, N2024-08-042024-08-0420040045-7906https://doi.org/10.1016/j.compeleceng.2002.07.001https://hdl.handle.net/11616/93692In this paper, robust gain margin, robust phase margin and Nyquist envelope of interval systems are studied. It is first presented that the robust gain and phase margins of a control system with an interval plant family are achieved at one of the Kharitonov plant by using the interlacing theorem and virtual compensator concept. Then, using the generalized Hermite-Biehler theorem, it is shown that the outer boundary of the Nyquist envelope of a stable interval plant is covered by the Nyquist plots of the 16 Kharitonov plants family. Examples are given to illustrate the method presented. (C) 2003 Elsevier Ltd. All rights reserved.eninfo:eu-repo/semantics/closedAccessNyquist enveloperobust gain marginrobust phase marginuncertain systemskharitonov theoremhermite-biehler theoremArticle30215316510.1016/j.compeleceng.2002.07.0012-s2.0-0345305833Q1WOS:000188713600006Q4