Abstract
This paper presents a novel 2-degrees-of-freedom (2-DOF) controller design for the robust vibration suppression positioning of mechatronic systems against the frequency perturbation in mechanical vibration modes. The authors have already proposed an linear matrix inequality (LMI)-based feedforward (FF) compensator design method to provide the robust properties in positioning against the perturbation, while the feedback (FB) controller has been independently designed to ensure the robust stability on the basis of the 2-DOF controller design concept. However, a problem still remains in the conventional design that the FB characteristic causes the deterioration of the FF control performance because the undesired response in the FB system due to the perturbation affects the ideal response by the FF compensation. The proposed controller design in this paper, therefore, includes the FB control system with the perturbation in the FF design model to solve the problem in the conventional design. In addition, the FB controller is optimally designed to improve the positioning performance as a cooperated design between FB and FF controllers. The effectiveness of the proposed approach has been verified by numerical simulations and experiments using a prototype.
