Abstract
Ship-mounted cranes are widely used in transportation and installation of heavy payloads on the seabed. It needs to meet rigorous requirements for efficiency and safety in severe sea conditions, and the unexpected motion of the crane due to sea waves makes it even harder to achieve the requirements. To prevent this, anti-sway control is used to minimize the motion of suspended payloads regardless of the ship’s motion. It is proposed here to use the adaptive control technique to control the sway motion of a knuckle boom crane. Using the augmented formulation for multibody systems dynamics, a nonlinear model of a knuckle boom crane system with a flexible cable mounted on the OSV is obtained. And it can be considered as a spherical pendulum attached to a three-link manipulator, whose actuators can be controlled and joint angles can be obtained. The control objective is to maintain the payload position while reducing the sway motion of payload in harsh weather and sea conditions.