Feedforward and feedback optimal control for linear discrete systems with persistent disturbances

Based on the quadratic cost functional index, the optimal control problem of linear discrete-time control systems affected by external persistent disturbances is developed. The main result concerns the existence and design of a realizable, robust feedforward and feedback optimal control law. It is shown that the optimal control law is realizable easily and more robust with respect to additive disturbances than that one of the classical feedback optimal control through simulation.