Combined controls of floating container cranes

We construct two controllers for floating container cranes based on the combination of feedback linearization, sliding mode, and proportional-derivative controls. The disturbances composed of viscoelasticity of sea water, elasticity of suspended wire rope, and sea-excited motions of ship are fully considered. The controllers simultaneously conduct four duties: tracking the trolley to reference, lifting the container to desired cable length, reducing the axial container oscillation and container swing. The simulation results reveal that the controllers work well and stabilize all the system responses.