Robust stability analysis of a class of uncertain large-scale systems with symmetrically interconnected subsystems

This paper considers the quadratic stability problem of a class of uncertain large-scale systems composed of several similar subsystems interconnected with an external system in a symmetrical fashion. A sufficient condition for the quadratic stability of such a system is given in terms of two modified subsystems with lower-order and corresponding H^∞-norms, and it is shown that the condition is also necessary for the quadratic stability of the overbounding system corresponding to the system. The uncertainties considered in the systems may be time-varying. However the values of the uncertainties are constrained to lie within some known admissible bounds