Stabilization of Cascaded Two-Port Networked Systems Against Nonlinear Perturbations
For control theorists, this provides a theoretical stability condition for a specific class of networked systems, but the result is incremental as it extends existing robust stability concepts to two-port NCS.
The paper models and analyzes a networked control system with cascaded two-port communication channels, deriving a necessary and sufficient robust stability condition for nonlinear perturbations in the transmission matrices, expressed as an arcsin bound on uncertainty norms.
A networked control system (NCS) consisting of cascaded two-port communication channels between the plant and controller is modeled and analyzed. Towards this end, the robust stability of a standard closed-loop system in the presence of conelike perturbations on the system graphs is investigated. The underlying geometric insights are then exploited to analyze the two-port NCS. It is shown that the robust stability of the two-port NCS can be guaranteed when the nonlinear uncertainties in the transmission matrices are sufficiently small in norm. The stability condition, given in the form of "arcsin" of the uncertainty bounds, is both necessary and sufficient.