Simulation Research Of Mooring Position Control System

Human come to ocean to collect resources with lacking of resources on land. The number of offshore structures is growing and they need to be positioned by mooring system.Anchor position system is a way of positioning when offshore structures working and positioning control is an important part of it. This paper works on the study and simulation of mooring position. The main work is done as follows:(1)This paper describes and compares different types of mooring systems. Then mathematical models of mooring positioning system and calculation of environmental load are studied. A nonlinear passive filter is designed to remove high frequency components in environment interference for reducing unnecessary loss of control system.(2)A fuzzy PID controller is designed for difficulty of adjusting PID controller parameters and it makes the control system of ship has adaptive characteristics. Simulation results show that: the fuzzy PID controller can improve dynamic and static performance of positioning system.(3)It’s difficult to determine the fuzzy control rules. So, the research on support vector machine is also contained in this paper with using parameters in controller as training samples. With its prediction ability, we can build predictive control system of mooring ship based on GA-SVM. The application of SVM can ensure system to get a good predictive control performance even in complex environmental conditions and without enough amounts of data.(4)The thruster assisted mooring positioning system is designed for ships work in deep sea. Its tension controller will track the total execution. The mooring system compensates slowly varying environmental forces and thruster compensates fast changing interference.The mooring system provides most of the executive power under the condition of steady environment so that reduce the consumption of propeller.(5)The paper studies how to determine the mooring line capacity and discusses several kinds of typical mooring system wiring way. By constructing the objective function and constraint condition, seek the optimal way of anchoring system. Then mooring line tension and the parameters of ship in new position can be obtained and they can be used to determine the mooring line capacity.