Anti-swing control for a double-pendulum offshore boom crane with ship roll and heave movements

This paper solves the anti-swing control problem for a double-pendulum offshore boom crane suffering from persistent ship motion-induced disturbances. Most existing articles treat the hook-cable-cargo system as a single-pendulum system, however, when the hook mass can not be ignored or the cargo is large in size, the hook-cable-cargo system exhibits double-pendulum effect. In such case, the existing single-pendulum-based control approaches cannot achieve satisfactory performances. This paper proposes a partial feedback linearization control method for the anti-swing control of a double-pendulum offshore boom crane in the presence of ship roll and heave movements. Specially, by using the Lagrange’s method, the dynamic model of a double-pendulum offshore crane is obtained. By inducing some elaborate variables, the original model is transformed into a more compact form. On the basis of the transformed model, a partial feedback linearization controller is designed and the stability is proven. Finally, simulation results are provided to verify the effectiveness of the proposed controller.