Abstract
In this paper, we propose a two-degree-of-freedom control method with a parallel feedforward compensators (PFC). The PFC plays a most important role in the stability of a proposed control system. Through the experimental results applied to a six-link electro-hydraulic serial manipulator, it is shown that the stability and the robustness against disturbances are improved by using the proposed control method. As the results of our previous papers, it was shown that the control method using disturbance observer designed by making use of H-infinity control theory is the most suitable among robust control methods. Through the comparisons with the results of the disturbance observer, it is ascertained that the proposed control method is also suitable for the control as well as the disturbance observer above mentioned. We examined and established the design criterion of the control system using the proposed method. The optimal parameters of the controller can be easily determined by using the design algorithm proposed here. The effectiveness of this proposed control method is verified through experiments of the six-link electro-hydraulic serial manipulator.
