Robust stability analysis of networked systems with varying delays

Robust stability conditions for Networked Controlled Systems (NCS) with uncertain, varying, bounded transmission delays and discrete-time static control laws are derived in this article. The delay uncertainty is shown to give rise to a discrete-time uncertain NCS model. The robust stability analysis is carried out via a linear matrix inequality approach which, when combined with a directed parameter search, yields an estimate of robust stability bounds on the maximum allowable delay (constrained within one sampling period) that the closed-loop system can tolerate. The presented simulation results show a drastic reduction of conservatism when compared with other techniques relying on the singular values of the perturbed NCS-model.