Active control of underwater installation

An augmented impedance control scheme is proposed together with passive heave compensation to achieve higher operability on offshore underwater installation. The dynamics of the controller, the crane, the water surface in the moonpool, and a detailed mathematical model of the hydrodynamic loads and load effects on the object hitting the water surface and proceeding through the splash zone are included. Stability of the controller is proven, and simulation results with relevant full-scale parameters are included.