Switched Lyapunov Function-Based Controller Synthesis for Networked Control Systems: A Computationally Inexpensive Approach

Abstract

This letter presents a Lyapunov function based control strategy for networked control systems (NCS) affected by variable time delays and data loss. A special focus is put on the reduction of the computational complexity. The crucial step to achieving computational efficiency involves defining a specific buffering mechanism that introduces an additional delay not larger than one sampling period. This allows representing the buffered NCS as a switched system, thus leading to a significant simplification of the NCS model and subsequent controller synthesis. The novel approach does not only circumvent the need for any over-approximation technique, but also leads to a strongly decreased number of optimization variables and linear matrix inequalities, allowing hereby greater flexibility with respect to additional degrees of freedom affecting the transient behavior. The performance and computational efficiency of the control strategy are demonstrated in a simulation example. Index Terms-Buffering mechanism, LMI based controller design, networked control systems, time-variable delay and data loss. I. INTRODUCTIONT HE GREAT potential of wireless networked control systems (NCS) characterized by controlling the plant over a (shared) communication channel together with significant developments of communication technologies have moved these systems to the center of attention within many engineering industries. This has been motivated by increasing complexity of modern control systems leading to the rapidly growing interest in characteristics the NCSs possess, such as great flexibility and adaptability regarding the system topology. Nevertheless, the main challenges which arise in NCS are communication constraints such as limited Manuscript