A practical optimal controller for underactuated gantry crane systems

In order to meet the operation requirements of fast anti-swaying and precise positioning of underactuated gantry crane systems, a practical optimal control scheme is presented based on the state differential equations for the swaying payload. The analysis of the system phase plane shows the swaying characteristics of the payload during the operations which determine the optimal timetable of accelerating and decelerating the cart, consequently, the specific anti-swaying controller is derived. To guarantee the precise positioning of the cart, the anti-swaying controller is redesigned to adapt both the requirements. As a result, the payload can be placed at the appropriate position with high efficiency. Finally, implemental results based on a scaled gantry crane demonstrate the feasibility of the proposed control scheme.