Research On Integrated Control And Simulation Analysis Of SWATH Ship

Small Waterplane Area Twin Hull(SWATH),as a kind of Catamaran vessels，is known tohave a longer natural period and a smaller motion amplitude.What’s more,campared withgeneral Catamaran vessels,its smaller waterplane area that provides less speed lose in wavesand lower probability of slams and deck wetness.In particular,the number of the passengers orcrew who are dizzy will decline.Because of its better seakeeping qualities,it is valuable inmilitary and civil application.However,the small waterplane area leads to a bad longitudinalmotion attitude.To solve this problem,the application of controllable fins is a default choice athome and abroad.SWATH ship has great practical prospects and value at home and abroad.For example,the first SWATH ship of the world,Kama Lino, change itself from an experiment ship intoone for people to take the tour boat successfully, and the unanimous approval of itsseakeeping,and even the seakeeping in higher sea conditions caused a world sensation.Sincethen, countries around the world are on this ship with a strong interest.There are someshortcomings,such as the Munk moment and the piece interference between the twin body,but it still causes a national R&D enthusiasm.China started late, but in cooperation withAustralia as well as analysis and design of702, some SWATH ship with advancedinternational standards emerged, such as the “north991” and “022missiles boat" which hasindependently developed by China.Thus the modeling, simulation and controller design is ofpractical significance.Firstly,through analysis for the structure characteristic and performance of the SWATH,amath model modeling method,which gets through theoretical and experimental and usecomputational fluid dynamics software as a supplement,is applied.Secondly,the SWATHmotion model is solved through the above method,and we can get the waves force,the fins liftas well as the hydrodynamic coefficients.Thirdly,a certain SWATH stability isstudied,moreover,the nature period,damping ratio and half-decay time are alsoderived.Finally,SWATH seakeeping qualities are not good enough when it is sailing in fivesea state,so a parameter self-setting fuzzy pid controller is designed for it.Furthermore,this paper does an exploratory research which presents the three degrees offreedom (roll,pitch,heave) combination control.And the optimal control theory is applied to design a control scheme of stabilizing fins.The simulation results show the controller forSWATH has a satisfactory effect.