Stabilizing control for an offshore boom crane with unknown parameters

Stabilizing control for an offshore crane which working on the sea is one of the research hotspots in the area of vibration control and many control methods have been proposed. Most of the existing control methods are designed based on the linearized model and with the assumption that the accurate values of the offshore crane system are available. However, in practice, the values of many system parameters such as jib mass, inertia moment are difficult to measure. Aiming at this problem, without any linearization to the complicated nonlinear dynamic model, this paper proposed a parameter independent coupling controller to stabilize the offshore crane with unknown parameters and ship roll motion induced disturbance. The closed loop stability is analyzed by using Lyapunov theorem and the effectiveness of the proposed controller is validated by simulation experiments.