Study On Dynamic Positioning Ship Control Method Based On T-S Fuzzy System

In recent years,with the ocean resource and inviolable rights increasd for China,dynamic positionning ships are more widely applied in many fields.The complex motion of it is composed of low and high-frequncy motion.Among them,the feedback loop is disturbed by the high-frequncy motion,leading to the unnecessary waste of the energy and wear of thruster,for low-frequncy motion is only counteracted by thrust system,it is necessary that high-frequncy composition of position and yawn measured value is filtered by filtration technology.Generally,marine motion velocity is not measured,in order to estimitate it,therefore,it is ncessary to use the state observer.In addition,because of disturbation of marine by complex condition outside,its process is regarded as the nonlinear system.Many nonlinear control methods have solved the inherent nonlinear property of marine dynamic movement,but it is restricted to adjust to parament variation and outside condition disturbtion.Morover,caculation is much more enormous.With respect to this,it has a very important practical and academic meaning that study on dynamic positionning ships based on T-S fuzzy system.The main research contents of this paper are as follows:Firstly it studies on the T-S fuzzy model of marine dynamic positionning system.The sterotype of dynamic positionning ships system include marine kinematics dynamics model;marine environment disturbtion mainly include sea wind sea wave and sea current model,these mathmatic models can be derived and transformed by T-S fuzzy method,which is the premise of the follwing problem study.Secondly it studies on the design of T-S fuzzy observer of dynamic positionning ships under the influnce of low and high-frequncy and condition disturbtion,which estimates state variable and unknown disturbtion.The fuzzy observer design can be classified two situations that are based on state variable formal of yaw angle,which is the observer design of known premise variable and that is the observer design of unknown premise variable.Finally it studies on T-S fuzzy system design and simulation based on the above fuzzy observer of dynamic positionning ships under the influnce of low and high-frequncy and condition disturbtion.By simulating results,it is verified that the control method validity of dynamic positionning ships based on T-S fuzzy system in real marine enviromennt.For the T-S fuzzy system design of known premise variable,which include two main sections,to begin with,it studies on T-S fuzzy controller,besides,it studies on T-S fuzzy system based on above fuzzy observer and controller,in which stabilized and sufficent condition are deduced and obtained by Lyapunov stability therome,convex analysis approch Schur completment lemma and linear matrix inequality(LMI)technique,to sum up,the design result is proved by simulation.For the T-S fuzzy system design of unknown premise variable,in the same academic method,the design result is also proved by simulation means.