The complex structured singular value
Automatica (Journal of IFAC) - Special issue on robust control
Multirate systems and filter banks
Multirate systems and filter banks
On the Kalman-Yakubovich-Popov lemma
Systems & Control Letters
Automatica (Journal of IFAC)
Survey Invariant representations of discrete-time periodic systems
Automatica (Journal of IFAC)
Hi-index | 22.14 |
This article is concerned with robust stability analysis of discrete-time systems and introduces a novel and powerful technique that we call noncausal linear periodically time-varying (LPTV) scaling. Based on the discrete-time lifting together with the conventional but general scaling approach, we are led to the notion of noncausal LPTV scaling for LPTV systems, and its effectiveness is demonstrated with a numerical example. To separate the effect of noncausal and LPTV characteristics of noncausal LPTV scaling to see which is a more important source leading to the effectiveness, we then consider the case of LTI systems as a special case. Then, we show that even static noncausal LPTV scaling has an ability of inducing frequency-dependent scaling when viewed in the context of the conventional LTI scaling, while causal LPTV scaling fails to do so. It is further discussed that the effectiveness of noncausal characteristics leading to the frequency-domain interpretation can be exploited even for LPTV systems by considering the @nN-lifted transfer matrices of N-periodic systems.