A Study On Ride Control Of Wave Piercing Catamaran Using The T-foil

Wave-piercing catamaran(WPC) is one of the typical representative of high performance ships, this ship has the feature of capacious deck area, high cargo capacity, stability and high speed,so application in merchant ships,warships has a increasing day by day. However,when sailing at high speed, pitching and heaving motions of wave-piercing catamaran drastically,the ship's seakeeping variation and bring some difficulties for storage of goods and equipment maintenance, also water on deck and appearance of trim by head caused have occurred,aggravating seasickness phenomenon, reducing passengers' comfort, which can cause danger at sailing. Thus, under the premise of wave-piercing catamaran with a high speed advantage,put forward higher requirements for its comprehensive performance include stability,seakeeping and other. This article will select the T-foil as the control device according to the characteristics of the longitudinal motion of WPC and then select the appropriate control algorithms to design ship control system, the wave-piercing catamaran attitude control were achieved.Firstly, analyzing and studying the development of the wave -piercing catamaran and comprehensive attitude control of the ship at home and abroad based on review of domestic and international data. Comparing the characteristics, installation limits and the working principle of anti-rolling device such as T-foil,trim tabs,interceptor etc,and then, the T-foil is adopted as the control foils in the paper.Secondly, establish the hull coordinate system, according to wave-piercing catamaran structural features, ignoring the effects on roll motion, establish model for ship rolling and pitching motions in two degrees of freedom and a solution method of parameters in the model is researched.According to strip theory,wave-piercing catamaran's hydrodynamic coefficients was obtained by seakeeper software. Adding different amplitude, different frequency regular wave together based on linear theory to get an irregular wave disturbance input to the hull.Study on anti-rolling effect of static T-foil different angle of the ship.Then, the airfoil, aspect ratio, wing area, pillar length and installation position of T-foil were optimized, the lift coefficient curve of T-foil was defined by simulation. Based on the static T-foil angle anti-rolling effect of the ship,a hydraulic system which used to driving the flap swing was added into the control system, determining the relevant parameters of pump-controlled hydraulic cylinders and hudraulic servo valve. The result shows that, the hydraulic system under external interference force still has high control accuracy and robustness in the PID control.The MPC with good control function is selected after study, and the working principle of the controller is introduced, established prediction model based on hydraulic drive and discreted the prediction model, verify that the terminal weighting matrix P is exist and the system is stable. Design the controller by MPC design Tool in MATLAB.Finally, simulation model was established in MATLAB and adjusting the MPC controlling parameters to realizing control of the pump-controlled hudraulic system, and effectively improve the seakeeping performance of WPC. The results show that the wave-piercing catamaran heaving anti-rolling is 29.87%, pitching anti-rolling is 63.32%, MSI reduced 15% than bare boat, effectively improve the movememt of the hull, the effectiveness of the controller is verified.