Optimal Tracking and Regulation Performance of Networked Control Systems with Time Delay and Input Quantization

This technical note investigates the optimal tracking and regulation performance of networked control systems (NCSs) with time delay and input quantization. To this end, advanced trade-off performance indices for multi-input multi-output (MIMO) systems are firstly proposed, aiming to identify new design constraints beyond those imposed by known limitations, such as unstable poles (UPs) and non-minimum phase zeros (NMPZs). Then, some analytical expressions of optimal tracking and regulation performance are derived using frequency-domain analysis and two-degree-of-freedom (TDOF) control techniques. The results demonstrate that the tracking and regulation performance of NCSs is influenced by the locations and directions of the NMPZs and UPs of the plant, network-induced time delays, quantization dead zones, and quantization densities. Finally, the validity of the conclusions drawn in this study is confirmed through simulation examples.