Adaptive roll stabilization of ships by U-tanks based on a novel control strategy

The application of passively-controlled U-tanks which have frequency adaptive function was introduced in this paper. The model of air-liquid flow in the U-tanks was established. On the basis of the model, relationship between the sectional area of air valve and fluid flow characteristics was researched. The optimized fluid motion was controlled by continuously turning the section area of air duct, which is calculated in generalized predictive control strategy. In this way, the fluid flow can be tuned to reduce the ship´s roll with the wave disturbance frequency varying. Simulation studies showed that the novel strategy can achieve more effective roll reduction compared with traditional intermittent control strategy.