Abstract
In this paper, we propose a design method of preview controllers. It is expressed by natural extension of the parametrization of all causal stabilizing controllers, which is derived by Youla, et al. What we do is to extend causal feedforward controllers to uncausal ones.
We use the two-degree-of-freedom control system in this paper, since there is no feedforward controllers in the one-degree-of-freedom system.
Moreover we get the parametrization of all preview controllers which follow the step responses, and then determine the optimal controller which minimizes the input/output responses with respect to L2 norm among all preview controllers.
The preview control has been considered in the perspective of the optimal control, therefore in the framework of the statespace method. Our approach to the optimal preview control in this paper can be considered as another approach using the transfer function method.
