Motion Simulation Of High Speed Trimaran And Research Of Ride Control Method

The high-speed trimaran as a representative of high-performance ship has become a hot research topic, due to its excellent performance .The main body and side body of the high speed trimaran are elongated structure made it have excellent speed and stability.However,vigorous longitudinal movement restricts high-speed trimaran to be widely applied.Therefore,the research of high-speed trimaran longitudinal Anti-rolling is of great significance. In the paper for a variety of conditions ,the reasonable control methods were adopted to design the controllers to control the T-foil which as the mechanical damping device and simulated and analyzed the damping effect of trimaran with T-foil.Firstly, using the ANSYS AQWA to analyze the hydrodynamic characteristics of trimaran, and then getting the trimaran’s hydrodynamic coefficients. Random Wave’s mathematical model is established according to the theory of random waves which cause the trimaran’s longitudinal movement. Then, considering the scale effect of real ship and ship model and using FLUENT to analyze the fluid dynamics analysis of T-foil and getting the lift model of T-foil.Thereby the longitudinal movement’s mathematical model of high-speed trimaran with T-foil is established.Due to study the size of lift force provided by T-foil at different angles , this article adopts the parameterized manager. The lift and lift coefficient under each of the angle of attack can be obtained that only needs once meshing and related solving parameter setting in FLUENT which greatly improves the efficiency of simulation.Then, studying the influencing factors of Trimaran’s longitudinal movement analyzing the Open-loop movement characteristics of trimaran.Through analyzing the trimaran’s longitudinal motion response under the regular wave in different frequency and under different speed , it is concluded that the frequency and the speed are the important factors influencing the trimaran’s longitudinal movement. Through analyzing the longitudinal motion response of trimaran with T-foil under the irregular wave to show the damping effect of T-foil more real.Finally, designing the attitude controller and simulating the effect of anti-rolling on trimaran. In order to better achieve the anti-rolling, two roll stabilization controller are designed based on the optimal quadratic control and sliding mode control theories. LQR control considers the coupling relation of trimaran’s pitching and heaving, and LQR control is easy to realize the state feedback of control system. Sliding mode variable structure control is suitable for solving the problem of uncertain nonlinear systems ,which has strong robustness.The simulation model of trimaran’s longitudinal motion control with T-foil is established based on MATLAB/SIMULINK, and simulation is carried out. The results of simulation prove that under the action of these attitude controllers, T-foil can effectively reduce the longitudinal movement of trimaran.