Abstract
This note studies the controllability and the observability for linear time-invariant uncertain systems whose system matrices contain uncertain entries that may take arbitrary large values. For a certain class of systems, it has been shown that a system is controllable and observable irrespectively of the bounds of uncertain entries if and only if the system has a particular geometric configuration called a complete generalized antisymmetric stepwise configuration. In this note, using the duality between the controllability and the observability, we show a necessary and sufficient condition for the system belonging a new class of systems to be controllable and observable independently of the bounds of uncertain entries.
