Ship Main/Flap Rudder-Main/Flap Fin Intelligent Robust Control

Main/flap rudder and main/flap fin are the effective way to improve ship's maneuverability.Nowadays,the main and flap rudders(main and flap fins) are connected by leaders or gears in engineering.It has certain angle ratio,and the effect of flap rudder(flap fin) is restricted.To exert the function of flap rudder (flap fin) fully,the thought that main and flap rudders(main and flap fins) are divided into two independent control systems is put forward in this paper.For the ship yaw/roll control,the system inputs are the main rudder angle,flap rudder angle,main fin angle,flap fin angle,so it also can be called vector control. Because there are many different main/flap rudder angles(main/flap fin angles) for a yaw(roll) lifting moment,the genetic algorithm is adopted to design the intelligent optimizing assignment rule of main/flap rudder angles(main/flap fin angles).There are disturbance and uncertainty existing in the system,and the robust control theory is adopted to design the system control rules.So the study content of this paper is ship yaw/roll-main/flap rudder-main/flap fin vector intelligent robust control,and the purpose is to enhance the course and roll control effect,low the energy consumption,and improve the system's robust performance.Firstly,the hydrodynamic performance model of main/flap rudders and main/flap fins were founded.This paper founded the calculating models of main/flap rudder and main/flap fin by their hydrodynamic coefficient chats.The reasonably regress models were chosen,and then the data sampling of chats was done.The coefficients of regress models were acquired by means of the least square algorithm.And the remarkable test was carried out to make sure that the regress models can be used in engineering calculating.Secondly,the system mathematic model of main/flap rudder and main/flap fin joint control for ship course/roll was founded.The ship's 3-DOF nonlinear coupling dynamic models of yawing,rolling and swaying were founded.The models of force and moment of main/flap rudder and main/flap fin were given. The disturbance force and moment of sea wave,wind and current were studied. The model of system driven energy was studied primarily,the driven energy equation of main/flap rudder(main/flap fin) was modeling by analyzing the moment that rudder servo system and flap rudder servo system(fin servo system and flap fin servo system) overcame,and it established the base for the design of control system.Then,the intelligent optimizing assignment rule of main/flap rudder angles (main/flap fin angles) was studied.For a restoring moment in the main/flap rudder (main/flap fin),there are many kinds of main/flap rudder angles(main/flap fin angles).So this paper studied the assignment rules of main/flap rudder angles (main/flap fin angles).And the improved genetic algorithm based on the infeasible degree(IFD-GA) was adopted to optimize the main/flap rudder angles(main/flap fin angles).And then,the ship course robust control system,the ship roll robust control system,and the ship course/roll synthesis coordinated robust control system were designed.The uncertainty of system models was analyzed.The theory of state feedback H~2/H~∞robust control based on linear matrix inequality(LMI),and the theory ofμrobust control were adopted to design those systems.At last,the system simulations were given with different sea conditions and encounter angles,nominal model and perturbation model.The simulation results showed that,compared with common rudder and fin in traditional control style, the systems designed in this paper had higher control precision,much less energy consumption,and better robust performance.Especially in high sea situation,the main/flap rudder and main/flap fin can provide bigger lifting moment,it improved the system's control ability for course and roll remarkably.