A New Method of Reducing Slid-ship\´s "Dolphin Movement" Phenomenon

The "dolphin movement" phenomenon of highspeed slid-ships will appear in the high-speed. The wet areas of the ship\´s bottom are little, and the damp coefficient of pitching movement is small. The conventional method of reducing it is that design the hull accurately through dynamical experimentation. And it needs high precision process. After the ship is produced, it is difficult to reduce the pitching movement through changing the hull shape. The anti-rolling devices for reducing the pitching movement such as anti-rolling tank and anti-rolling fin can\´t be build in the slid-ships. And the most conventional anti-rolling models are passive. The paper used the active impetus anti-rolling technology. It forecasted the heave and pitching movement used the simplified model of high-speed taxiway heave and pitching differential equations in regulation waves. Then adapt water-jet propulsion to reduce ship\´s "dolphin movement" based on PID control method, and used the fuzzy adjuster to change the PID parameters to match the value of the changing damp coefficient. Through MATLAB software system, the simulation results indicate that fuzzy PID controller to effectively limit "dolphin movement" phenomenon.