Inverse kinematic control of an industrial robot used in Vessel-to-Vessel Motion Compensation

An increased level of complex offshore load handling operations is expected due to an increased amount of floating wind turbines, remote fish farms, and autonomous shipping, and in general more advanced operations to be carried out at sea. A common problem for these applications is that both equipment and personnel have to be transported between two floating vessels at sea. An investigation of the Vessel-to-Vessel Motion Compensation (VVMC) problem may increase the efficiency and safety of such operations in the future. In this paper, a control algorithm has been developed and experimentally tested in the Norwegian Motion Laboratory featuring two Stewart platforms (SPs), an industrial robot, two Motion Reference Units (MRUs), and a Maritime Broadband Radio (MBR) used to establish a real-time wireless communication link. The resulting overall compensation error is measured to be no more than 41.9 mm during the experiments.