The design method of two-degree-of-freedom controller using μ-synthesis and its application to two-mass system

This paper presents the design method of two-degree-of-freedom (2 dof) controller system based on the internal structure Firstly, we show the internal structure of the system and derive the condition which clearly shows the equivalence between the disturbance observer based controller and the generalized 2 dof controller. Secondly, we propose the design method of free parameter using μ-synthesis taking into account the structure of the system and the tuning of the Q so as to satisfy the derived conditions. Finally, we show some simulation results of velocity control of a 2-mass system and confirm the effectiveness of the proposed method