Control Strategy And Simulation Of Ship Anti Roll Slider Device

When the ship is sailing on the sea,it will inevitably be affected by the external environment such as wind,waves and other disturbance factors,which will cause the ship rolling.The rolling motion of a ship will not only affect the seaworthiness of the ship and the comfort of the people,but even cause the ship to capsize.In order to reduce the rolling motion of the ship,this dissertation takes the anti rolling slider as the research object,and analyzes its anti rolling performance through the simulation data.In this dissertation,the wave motion model needed in the simulation of ship rolling motion is analyzed and established firstly.Taking a real ship as an example,the model of ship rolling motion is established and simulated in Matlab.The simulation results prove the validity of the model.Then,the control algorithm of ship anti roll slider is simulated.In this dissertation,the anti rolling effect of common PID control algorithm is simulated and analyzed,and the limitation of PID control is found.For some specific sea conditions,the anti rolling effect is not ideal.Considering the uncertainty of sea state,an improved PID control method based on PSO algorithm（pso-pid）is proposed in this dissertation.By comparing the simulation results under two kinds of control,It is verified that the anti rolling effect of pso-pid is more stable under the interference of external environment,reaching about 70%.Because pso-pid is easy to fall into the local optimum,the convergence of the algorithm is not good,and finally the control effect does not reach the expected goal.In this dissertation,the dynamic fuzzy neural network algorithm（DFNN）is applied to the anti rolling slider system.The algorithm combines fuzzy control with neural network.It not only overcomes the shortcomings of fuzzy control and neural network,but also inherits their advantages perfectly.Moreover,the algorithm has the ability to extract fuzzy rules directly from sample data,so it is especially suitable for the complex industrial control process problems which lack of expert experience and knowledge.The simulation results show that DFNN is better than PID and pso-pid in roll reduction and the roll angle is controlled within 2°.The feasibility of applying DFNN to the control of ship anti roll slider system is verified.