Control of Load Sway in Enhanced Container Handling Cranes

This paper describes the design, implementation and control of an enhanced container quay-crane. The new crane is based on a novel reeving arrangement which allows both fast and accurate gross motion as well as fine micropositioning. The paper describes the essential theory behind the mechanical design and the design of a controller that minimises load sway. The controller uses measurements of the rope tensions to provide artificial damping of the load. Experimental results from a 1/15th scale model are presented. The control strategy was found to be extremely effective, damping spreader oscillations within two or three cycles.