Internal structure of two-degree-of-freedom controller and its application to vibration suppression control

In this paper, the authors formed a link between the heuristic controllers used in the industry and the theoretical generalized controller. First of all, we clarify the internal structure of the generalized two-degree-of-freedom controllers which yields a link between the theoretical researches and the practical applications. This is particularly useful in the applications where the guidelines on the design of the controller can be obtained from the physical insights of the systems. Secondly, we indicate how to blend identification and control together without any modification of the controller. This is in fact the problem of closed-loop identification. This can be considered also as the identification part of the auto-tuning technique. Thirdly, we propose a new design technique of a free parameter taking into account a robust stability based on the information obtained from the identification. Finally, we apply the proposed algorithm to vibration suppression control, and show some simulation results to verify the effectiveness of the proposed algorithm