Abstract

In this paper we study stability radii of positive linear difference equations under arbitrary affine parameter perturbations. It is shown that real and complex stability radii of positive equations coincide for block-diagonal disturbances. Moreover, for these stability radii, estimates and computable formulae are derived which generalize to positive linear difference equations known results obtained earlier for positive linear discrete-time systems of the form xðk þ 1Þ ¼ AxðkÞ, k 2 N. Some illustrative examples are given.