Study Of Fin Stabilizer Intelligent Control System For Ship Under Heave Scale Sea

Fin Stabilizers are the special installments that help the ships to reduce the rolling initiatively. The ships rolling movement is fierce and is a high nonlinear system,under heave scale sea. Utilizing the entity ship in the sea experimental to study the fin stabilize system's performance, has possibility that fin stabilizers are damaged and ships capsize, which is costly and dangerous. Based on this, this article realizes ships' nonlinear rolling condition under heave scale sea through the computer condition. The problem that unable to use the entity ship to carry on marine experiments is solved. Simultaneously, the questions exist are analyzed. Attempt to use the intelligent method to improve the controller. Study the main/flap fins' structure and the performance. Carry out the contrast simulation research with monomer fins.Firstly, according to the constituent of fin stabilizer electro-hydraulic servo, each links structure and nonlinear factors are analyzed, nonlinear model is established. Ship's rolling nonlinear model and monomer fins' hydrodynamic model are built. Main/flap fins' data smoothing analysis are carried on, regression is accomplished by using the least squares method, main/flap fins' hydrodynamic model is built. Study the stochastic ocean wave simulation method. The nonlinear model of ship stabilize system is built.Next, GA-FC controller is designed to improve the compatibility of PID controller. The reason of low simulation precision is analyzed, changeable precision is put forward. Follows the principles of simple structure and easy to realize, the GA-FC PID compound controller is designed.Afterwards, the method of improving the stabilization performance from the fin piece own structure is brought forward. Monomer fin is replaced by main/flap fin to produce bigger restoring moment.Finally, the simulations in different sea conditions and encounter angles are carried out. The curves and statistic values of 3 kinds of control methods, 2 kinds of fins are given. The result indicated that the GA-FC PID compound controller has higher course control precision, better robust performance. The stabilization effect of the main/flap fin stabilizer is 1.2～1.5 times that of monomer fin stabilizer, and is an effective way of reducing the ships rolling effect.