Robust design of unconstrained predictive controllers

A systematic and complete design procedure for robust predictive controllers is proposed. The synthesis method is based on rigorous theoretical foundations, without resorting to approximations or ad hoc design guidelines, yet it remains a viable tool for practical utilization. A significant feature is that the robustified predictive controller retains the servo performance of a nominal predictive controller designed using conventional methods. In addition, the robust predictive controller can be designed to guarantee perfect steady-state rejection of asymptotically constant disturbances. The robust design method is developed for systems affected by unmodeled dynamics, and is based on solving a discrete-time model-matching problem. It is shown that the robustified controller can legitimately be classified as a predictive controller. An illustrative design example is given