Robust Mean and Variance Control for Second-Order Linear Uncertain Systems

In this paper, a controller based on state variable mean and covariance is proposed for the robust control of second order linear uncertain systems. On the basis of the mathematical description of a typical second order linear uncertainty system, the mean and covariance of state variables are obtained by using the Covariance Analyse Describing Equation Technical (CADET) based on Gaussian hypothesis. The mean-value controller and covariance controller are designed to transform the control of an uncertain system into two deterministic systems aim to control the mean and steady covariance of state variables. A mathematical simulation is carried out for uncertain input as sine signal and white noise signal in order to verify the performance of the designed robust controller. The simulation result shows that, the proposed robust controller based on mean value and covariance improves the steady state characteristics and dynamic characteristics of the control process and improve the robustness of the system to the uncertain input compared with PD controller