On Stability of Sequence-Based LQG Control

Sequence-based control is a well-established method applied in Networked Control Systems (NCS) to mitigate the effect of time-varying transmission delays and stochastic packet losses. The idea of this method is that the controller sends sequences of predicted control inputs to the actuator that can be applied in case a future transmission fails. In this paper, the stability properties of sequence-based LQG controllers are analyzed in terms of the boundedness of the long run average costs. On the one hand, we derive sufficient conditions, each for the boundedness and unboundedness of the costs. On the other hand, we give bounds on the minimal length of the control input sequence needed to stabilize a system.