Research Of Marine Dynamic Position System Based On Nonlinear Model Predictive Control

Since"16^th National congress”state makes more attention and support for marine equipment technology,as well as the increasingly surrounding contradictions along with our country make the comcept of the construction of sea power is constantly strengthened.It is necessary to develop Marine equipment for building the sea power of state,Marine DP system is one of the important technology of Marine equipment,such as Marine vessels,work platform,has been taken seriously by the researchers and continuous attention,and is also one of the important subjects in this area which we study.The focus of this project is to use FOSSEN modeling theory to establish a complete mathematical model of the ship.After combining the feedback linearization and the MPC algorithm,the ship dynamic positioning controller is designed.Finally,simulation is carried out to verify the simulation.The simulation results show that the control system is effective.The overall framework of this thesis is to introduce the practical significance,development of history and research status of DP system.Through the introduction,we can understand the overall layout of DP system and totally grasp the related technologies,and have a certain understanding about the working process and principle of the method of the DP system at the same time.Then,through the analysis of FOSSEN modeling theory,we established a complete nonlinear mathematical model of the ship,including kinematics,dynamics and dynamic mathematical model.In the third chapter of this paper we designed for the DP system nonlinear estimate filter to solve some unpredictable state when ship modeling and processing of the high frequency signal of disturbance to the influence of the controller,at the same time,we has carried on the analysis of the advantages and disadvantages for various forms of filter,and the mathematical analyze and simulation prove that the nonlinear estimate filter has the perfect stability effect.In the fourth chapter the application of theory of the DP controller which we designed in this paper has carried on the explanation,such as the feedback linearization method and the MPC theory,two kinds of processing nonlinear control system is introduced,and the linearization control method is selected,the principle of feedback linearization and development as well as the principle and characteristic of the MPC has carried on the detailed instructions.Finally,we give the focus of this paper and the design of the controller,and the simulation results show that the DP control system designed in this paper meets the design requirements.Through a series of method and theory is introduced,as well as the good simulation results of the designed controller and estimated filter,it is proved that the designed controller can achieve the dynamic positioning of the ship's motion.The theoretical analysis and simulation verification of the DP controller can save a lot of time for subsequent physical experiments.At the same time,it has reference value for the subsequent researcher's about control method of the DP system to the later researchers,and the control system of ship DP application has a certain application prospect.