Nonlinear Control Method Of Dynamic Positioning Based On Kalman Filter

With the continuous exploration of marine resources,a series of marine engineering construction of the ship dynamic positioning accuracy and stability of the increasingly demanding.The dynamic positioning system is a nonlinear motion system with various environmental disturbances.The realization of the system function is that the ship relies on its own thrust to counteract the influence of low frequency interference in the environment without responding to the influence of high frequency interference.Therefore,in the ship dynamic positioning system,filtering and state estimation is very important,it is an important part of the dynamic position system.The focus of this paper is to study the filtering of high frequency measurement noise,the estimation of ship position and velocity,to explore the optimal filtering and state estimation method,so as to improve the accuracy of dynamic positioning control.The main research work is:The modeling of the ship under the complex sea conditions of the interference.The model of the ship is simulated by Matlab/Simulink,and simulated the motion of the ship under complex sea conditions to meet the task requirements of this research.Based on the nonlinear observer model of ship motion equation,the stability of the nonlinear obseryer model is proved by combining the passive theory with the Lyapunov theory,and it is applied to the closed-loop dynamic positioning system of the structure.The simulation is carried out in the filtering and state estimation to analyze the effect of the application and verify its effectiveness.The Kalman filter control modeling of the ship movement is also applied to the ship dynamic positioning system,used to analyze its optimal effect and application form in the process of filtering and state estimation.The simulation results of Matlab/Simulink are compared with the nonlinear observer simulation results,so as to explore the optimal filtering and state estimation methods.Finally,based on the above research,a set of optimal filtering and state estimation method(OFSE)is constructed,and OFSE control is constructed.Simulation analysis is carried out under Matlab/Simulink.By comparing the interference of ambient noise in different sea conditions,the effectiveness of the method in improving the accuracy of filtering and state estimation is verified,and the precision of ship dynamic positioning system control is further improved.