ABSTRACT
With the development of global marine economy, transportation operations of marine cranes are becoming more and more frequent. In the marine environment, sea breeze and waves have an impact on ships, thereby producing movements of heave, lengthways tilt, and lateral tilt. Therefore, the study of wave active heave compensation control technology is increasingly urgent. In this study, through the offshore ship motion and crane heave motion analysis, we try to understand that heave, lateral tilt, and lengthways tilt have the biggest impact on ship. Furthermore, mathematical models of ship motion are established. Through the analysis of the motion equation for marine cranes in deep sea, wave compensation should consider the vertical movement compensation of the ship. Then, by considering the compensation of other degrees of freedom, lateral tilt and lengthways tilt are transferred to the heave direction, so the compensation control of ship motion becomes the main heave compensation. From the aspects of velocity compensation and displacement compensation, control principle of marine crane active heave compensation is analyzed. Finally, a scheme of marine crane active heave compensation control system is designed.
