Robust tracking control of networked control systems included uncertainties

In this paper, a novel robust tracking control (RTC) approach is developed for networked control systems (NCSs) included uncertainties, such as random delays, packet losses and disturbances. Different from the existing control techniques for NCSs, the RTC scheme is a hybrid robust controller with variable sampling period. Firstly, the delay and packet loss information are online updated. This information is then used to configure the controller as well as to estimate the delays at the coming step to optimize the sampling period by using an adaptive grey model (AGM). Secondly, the hybrid robust controller based on quantitative feedback theory (QFT) and robust state feedback theory (RSF) to compensate the bad effects of both the imperfect network and the disturbances on the system performance and consequently, ensure the stable tracking performance. Real-time control experiments are finally carried out to illustrate the effectiveness of the proposed metPhod.