Two degrees of freedom (2DOF) control strategy is in the interest of control scientists since, it provides more flexibility in controller structure and design to satisfy the objectives of control problems like stability, disturbance rejection and robustness. In the other hand, the concept of two degrees of freedom controllers is mainly used in many control schemes. In these methods one controller is responsible for providing stability during the control task and the other one provides perfect tracking for the desired states. First, the left; TEXT-INDENT: 21.55pt; MARGIN: 0cm 0cm 0pt; unicode-bidi: embed; DIRECTION: ltr" Key words Hybrid control, fuzzy-LQR, electro hydraulic servo system, fuzzy-PD.
