Research On The Parameter Identification Method Of Ship Pitching And Heaving Motions Based On Improved Particle Swarm Optimization

With increasing economic development,ability in marine transportation plays a crucial role in the strength promotion of countries and the position of ship motion model is more noticeable.Mastering the ship motion model is the basis for research on the ship maneuverability.Parameter identification method to obtain the hydrodynamic parameters performs better than the classic method because the parameter calculating is not accurate.Particle swarm algorithm(PSO)breaks into people's field of vision with its unique performance comparing with classical identification methods.Practice in more and more fields has proved its stability and precision.This paper introduces the mechanism of cellular automata to optimize PSO algorithm.And the cellular PSO optimization algorithm is applied to the ship hydrodynamic parameter identification,translating the hydrodynamic parameters obtaining issue into an optimization problem.This paper firstly introduces the characteristics of PSO algorithm.The influence of the topology and parameters selection to algorithm performance is tested and analyzed.Next,the explanation to the deficiency of particle swarm algorithm is made so cellular mechanism is introduced and its related cellular automata theory is described.Then,two improved form,inner and outer cellular PSO algorithm,are designed.And we make two sets of comparative experiments with four standard test functions to verify the effectiveness of the proposed method.Afterwards,the ship pitching and heaving motion model is constructed,identification method is designed,the specific steps identification method are described,the rudder angle input modeling and wave disturbance input modeling are built.Then the identification of ship hydrodynamic parameters is carried through.The simulation experiments on still water and wave disturbance cases with or without noise are carried on.The results and analysis of the results verify the reliability and accuracy of this identification method.