Internally Positive Representations and Stability Analysis of Linear Difference Systems with Multiple Delays

This work introduces the Internally Positive Representation of linear continuous-time difference systems with multiple delays. The technique, originally developed for delay-free linear systems, and recently extended to differential systems with multiple delays, proved to be a useful tool to exploit results available for positive systems also for systems that are not positive. As a result, a sufficient delay-independent stability condition for difference systems with constant delays is given, which is shown to be less conservative than similar existing results.