Asymmetric sufficient condition for stability robustness of singular systems with structured parameter uncertainties

In this paper, under assumptions that the linear nominal continuous-time (o r discrete-time) singular system is regular, impulse-free, and asymptotical ly stable, an asymmetric sufficient condition is proposed to preserve the a ssumed properties when the structured (elemental) parameter uncertainties a re added into the nominal singular system. The corresponding stable region in the parameter space that is obtained by using the proposed asymmetric su fficient condition is not necessarily symmetric with respect to the origin of the parameter space. An illustrated example, in which the signs and rang es of the parameters are known although their values are uncertain, is give n to show that the proposed sufficient condition may yield less conservativ e results than the existing ones reported recently. (C) 2001 Academic Press .