Certain State Optional Research On FPSO Dynamic Positioning Control

FPSO is a newly-grown oil drilling vessel and it is playing a more and more important role in drilling oil. In normal state, FPSO is moored in its operation sea area for a long time by single-point mooring, which is turning with single-point due to environmental loading such as wind, current and waves. Now FPSO is influenced a little due to environmental loading such as wind, current and waves. But sometimes owing to working for FPSO or other ships, we must let FPSO stay in a certain area. Now FPSO is influenced a more due to environmental loading such as wind, current and waves. Based on the theory of FPSO positioning control, the auther adopted Zoutendijk feasible direction method to research FPSO positioning control.In this paper, we introduce the necessity and significance of positioning system and the state of art of present research. By comparison of three positioning techniques, we proposed a positioning scheme which is based on Zoutendijk feasible direction method that aims at non-linear constraint problem to solve FPSO positioning. According to the formula of computing environmental loading, in connection with data at certain state of FPSO, we worked out the environmental loading force which ensures the application of optimization algorithm. According to the reference positioning model of FPSO, considering its positioning area, regarding its external force as target function, variable angle as constraint condition, we performed motion simulation analysis of FPSO, finally carried out positioning control optimization research based on Zoutendijk feasible direction method.With application of this computation code, we can quickly and accurately determine the mooring angle of FPSO at which the external force is minimal. Compared with excellent selection positioning control method, this optimization scheme can not only improve computational efficiency at certain positioning angle, but also apply to other types of ship when changing parameters, so this method has advantages and practical value for engineering.