“…When studying the stability and control of singular systems, an aspect to be considered is ensuring the admissibility, that is, the regularity, impulse-absence and stability of the system. Moreover, in suboptimal control problems, such as H ' control and guaranteed cost control, it is desirable to design feedback controllers guaranteeing not only the admissibility of the system, but also an adequate level of system performance (Boukas, 2011;Chaibi et al, 2021;Charqi et al, 2020;Sheldon et al, 1972;Wei et al, 2019). Various interesting results of this problem have been presented (Fridman and Shaked, 2005;Khongja et al, 2018;Kwon and Park, 2006;Thuan et al, 2019;Wang et al, 2012), where there were sufficient conditions for designing guaranteed cost controllers of large-scale systems with delays; however, the singularity was not addressed in these papers.…”