Time-domain Simulation Study Of Float-over Installation Based On DP System Under Influence Of Fender

Dynamic positioning(DP)system relies on the control system and propulsion system to reach the goal of positioning,thus DP system isn't influenced by the depth of water.Comparing with traditional mooring system,cost of DP system won't increase while water goes deep and positioning capacity won't be influenced.Also,dynamic positioning system needs almost no support vessel,less installation expense,not to mention the flexibility if DP system is better than mooring system.As prospecting and exploiting of ocean resource goes further from the coast and deeper,it is reasonable to believe that float over installation using DP system is to gain more attention as for its alignment with the large scale deep water platform operation.A brief introduction to the dynamic positioning system is given,including its definition,grade,principles of operation,components and development history,which illustrates the important practical significance of the research of the dynamic positioning system.Timedomain simulation based on different control theory of docking process of float over installation using dynamic positioning system is conducted,the influence of fender is also taken into consideration.Firstly,a time-domain simulation program based on PID control is built.Simulation of four different environment conditions is conducted.Trajectory,positioning error,fender force,thrust is gained from the result.Then a time-domain simulation program based on back stepping is built,simulation of four different environment conditions is conducted as well.Some useful conclusion and data is gained through comparison of two different control system and four different environment conditions.