Stability robustness of singular systems with time-varying structured parameter uncertainties

In this paper, under assumptions that the linear nominal singular system is regular, impulse-free and asymptotically stable, a sufficient condition is proposed to preserve the assumed properties when the time-varying structur ed parameter uncertainties are added into the nominal singular system. The corresponding region of preserving the assumed properties, that is obtained by using the proposed sufficient condition, in the parameter space is not necessarily symmetric with respect to the origin of the parameter space. Wh en we consider the standard state-space systems, the proposed sufficient co ndition becomes a simplified form which coincides with the one reported in the literature.