Sway suppression of an offshore container crane

In this paper, a method to suppress the sway motion of an offshore container crane is discussed. The offshore container crane is used to load/unload containers between a huge container ship (called the “mother ship”) and a smaller ship (called the “mobile harbor”), on which the crane is installed. The load/unload control objective is to suppress the pendulum motion (i.e., “sway”) of the load in the presence of the mobile harbor (heave, roll, and pitch) induced by wave and to compensate for the ship motions to keep the spreader at the desire position. Experiment results are provided to demonstrate the ability of the proposed control law.