Robust H∞ control of single input-delay systems based on sequential sub-predictors

This study presents an approach to the H-infinity control of linear input-delay systems. First, an H-infinity state predictor is introduced for dead-time systems with disturbance input and measurable outputs. The author's proposed method focuses on optimisation of the disturbance propagation in sequential sub-predictors (SSP). Each of the predictors is employed to forecast the state for one portion of the delay. The H-infinity performance of the prediction error can be improved by increasing the number of predictors. Consequently, an H-infinity controller is designed for the standard H-infinity problem of dead-time systems using SSP. More importantly, the SSP method is extended to the robust H-infinity control in presence of uncertainties. Some examples are given to illustrate the effectiveness of proposed method.