Tracking Performance Limitations of Networked Control Systems With Repeated Zeros and Poles

In this article, the performance limitations problem are investigated for a class of signal-input, signal-output networked control systems with repeated zeros and poles. The additive white noise is adopted in the communication channel. The tracking performance limitations are investigated based on a two-degree of freedom (2DOF) controller. The results demonstrate that the multiplicity of nonminimum phase (NMP) zeros and unstable poles of the plant can affect the tracking performance limitations. The explicit quantitative relationship is characterized for the tracking performance limitations, which is derived based on NMP zeros, unstable poles of the plant with corresponding multiplicity, as well as the statistical characteristics of the reference noise and communication noise. The admissible infimal signal-to-noise ratio (SNR) is also obtained for the tracking system by using a 2DOF controller structure, where the admissible infimal SNR can satisfy the stability conditions while achieving tracking performance limitations. Finally, an illustrative example is presented to validate the effectiveness of our proposed scheme.

Automated summary

This article investigates the performance limitations of a class of networked control systems, finding that the multiplicity of NMP zeros and unstable poles can affect the tracking performance. A quantitative relationship for tracking performance limitations is derived based on statistical characteristics. Additionally, a minimum signal-to-noise ratio is obtained using a 2DOF controller structure for the tracking system.