Vertical Stabilization Control for Trimaran Based on Resultant Force and Moment Distribution

The vertical movement of a trimaran caused by external disturbances during sailing, may lead to seasickness of the passengers and damage of the equipment onboard. Based on computational fluid dynamics (CFD) calculations, the hydrodynamic coefficients are obtained and a mathematical model of the trimaran is established, and with experiments of trimaran sailing in water tanks, the hydrodynamic coefficients solved by CFD are verified. Then, the T-foil and flap are designed, and the lift force and moment are solved by CFD. Next, the slope of the force of different attack angles on the T-foil and flap is obtained by the polynomial fitting. Finally, the trimaran vertical stabilization proportion and derivative (PD) controller, based on the sigmoid function, is designed with a new method of the resultant force and moment for a dynamic decoupling T-foil and flap. Through the simulation of trimaran movements systems with active T-foil and flap, the PD parameters are obtained. Then, the effect of the controller on trimaran vertical stabilization is verified by the experiments in the water tanks.