Stabilization of Networked Control Systems with Long Varying Time Delay Based on Two Steps Transformation

It is well known that networked control system can be modeled as a discrete model with a multiple steps delay in two control items when the network-induced delay is longer than a sampling period. Based on this discrete model with a multiple delay in two control items, a new model of networked control systems is got by two steps transformation. One control item with time delay is disappeared in this new model. The existing conditions of asymptotic stability for networked control system with long time delay are presented by Lyapunov method and robust control theory. The design method of stabilization controller for networked control system is proposed in terms of linear matrix inequalities. Comparing with the results in literature reported, the dimension of LMI used in this paper is the lowest. In the end the simulation based on the networked control unstable system is studied. The simulation results show the proposed controller is feasible and effective.