Research And Simulation For Ship Dynamic Positioning Based On The ADRC

Due to the complicate marine environment, the strong interference to the ship, and the nonlinear, uncertainty of the ship model, high demands to the ship dynamic positioning system are put forward. Through research, it finds that linear active disturbance rejection control (LADRC) has strong anti-interference capability, less control parameters and is not based on accurate model etc. This paper uses LADRC to design the controller, and takes "Beihaijiu115" as study object to take the simulation research on it.In the first part, this paper summarizes the present development situation of ship dynamic positioning system, establishes the mathematical model of ship motion and wind, wave, current disturbances model, and then according to the data of "Beihaijiu115", establish the mathematic model of dynamic positioning, and through the simulation of turning trial to prove the validity of the model, thus laying the foundation for the controller design.Secondly, this paper introduces the principle and composition of ADRC, and briefly describes the tracking differentiator (TD), extended state observer (ESO), nonlinear feedback control rate (NLSEF) and algorithm. Later, the basic principle as well as the basic algorithm of ADRC linear are given in detail.Finally, this paper researches and designs linear active disturbance rejection controller, makes simulation by MATLAB. Analysis the anti-interference capacity robust ability of LADRC controller in an lower disturbance sea condition and higher disturbance sea conditions; by changing the parameters of the ship to analysis the model parameter adaptation of LADRC. Then, design the Back-stepping controller based on LESO, therefore explore the LESO application.The main work of this paper is to establish the mathematical model of ship motion, and to design the LADRC controller for dynamic positioning, and to discuss the application of LADRC on dynamic positioning system. The results of simulation show that the controller we design with LADRC for dynamic positioning is effective.