Analyze and constrained control of ship roll motion for frigate navy with active fins

One of the most important of ship motions in sea waves is roll, which causes transverse and vertical accelerations and loss of operational performance of the frigate warship by making limitation in comfort, workability, safety, reduce the performance of weapons and navigation equipment as well as increase the mission time and energy consumption. To prevent these events it is essential selection of suitable stabilizer and control system .The purpose of this research is, analayze of roll motion and suitable controller design for decreasing the amplitude of this motion. for this is extracted suitable fin-roll model as well as computational fluid dynamics method for the fin-roll stabilizer, and flow analysis was done. Because there are fin constraints, in particular the dynamic stall and mechanical fin angle saturation, the constrained control was designed for fin-roll system and the results were compared with PID controller results. The results showed the LQR control had positive effects on significant reduction in the roll amplitude and achieving to the roll operational performance of the frigate warship according to NATO standard.