Robustness of a discrete-time predictor-based controller for time-varying measurement delay

Robustness properties for different uncertainties of a predictor-based control of time-delay systems are analyzed in this paper. First, a time-varying delay dependent stability condition is expressed in terms of LMIs. Then, uncertainties in the knowledge of the plant parameters and the sampling time period are considered. In addition, the resulting closed-loop system is shown to be robust with respect to these uncertainties. Moreover, this scheme has been tested in a real-time application to control the roll angle of a quad-rotor mini-helicopter. The experimental results have demonstrated the good performance of the proposed scheme and the robustness even in presence of long delays uncertainties.