Networked Control of Unstable Resonant Systems

In this paper the control of unstable resonant plants through the communication network is considered. The concept of conditional stability related to some model parameters is reviewed. In particular, the delay conditional stability is introduced. In networked control, the delays induced by the communication network may allow the stabilization of the controlled plant, as well as its destabilization. These delays may be time variant and/or stochastic, but bounded. The limits of the delays are easily computed by using traditional frequency domain techniques. An example illustrates the procedure.