Two-degree-of-freedom control of a stacker crane

This paper presents a motion control of a stacker crane applying a two-degree-of-freedom control. The two-degree-of-freedom control system consists of a feed forward controller based on an inverse system and a feed back controller with suppressing the vibration effectively and stabilizing. Feedback control of the motion of the stacker crane is derived by considering the time rate of change of the total energy of the system. This approach has the advantage over the conventional methods in the respect that it allows one to deal directly with the system´s partial differential equations without resorting to approximations. The paper concludes by presenting some numerical results and experimental results for a special case using a proposed control system. These results show that the two-degree-of-freedom control system can realize faster and precise tracking control of the flexible stacker crane system.