Advanced sliding mode control of floating container cranes

This article constructs two robust controllers using sliding mode control (SMC) techniques. The ship-crane system is operated in the complicated condition in which the disturbances due to viscoelasticity of seawater and the flexibility of handling cable are fully taken into account. With two actuators composed of trolley-moving force and container-hoisting torque, the controllers 

concurrently stabilize six states consisting of trolley displacement, container lifting motion, container swing, axial container oscillation, ship roll and heave. The quality of control algorithms is investigated thru simulation. The results show that the responses of crane are asymptotically stabilized and ship vibrations are significantly reduced.