Parameter Identification Of Ship Longitudinal Motion Based On Centroid Particle Swarm Optimization

The hydrodynamic parameters are important parameters for establishing the mathematical model of ship motion.However,the hydrodynamic parameters calculated by classical methods such as pool experimental measurements and theoretical formulas are difficult to guarantee due to the existence of scale effects.For some hydrodynamic parameters with higher sensitivity,It is difficult to solve by classical methods,so the calculation of accurate hydrodynamic parameters plays an important role in the establishment of mathematical models of ship motion.Advanced parameter identification technology is more excellent in solving the above problems.Particle swarm optimization is an important branch of swarm intelligence.The algorithm mainly imitates the aggregation and foraging behavior of the birds to perform iterative optimization.Based on the basic principles and convergence problems of particle swarm optimization,this paper introduces a centroid model to improve the particle swarm optimization algorithm and applies it to the longitudinal motion parameter identification of ships.Firstly,based on the theoretical analysis of the Particle Swarm Optimization(PSO)algorithm,the optimization of the defect-induced centroid model of the PSO algorithm is carried out,and the improved centroid particle swarm algorithm(Centroid Particle)is described in detail.Swarm Optimization(CPSO)improved the idea of CPSO convergence.By using four benchmarks to improve the algorithm,it is verified that the improved PSO algorithm makes up for the disadvantages of the basic algorithm and obtains a more satisfactory optimal.solution.The method and specific steps of CPSO to identify the hydrodynamic parameters of longitudinal motion of the ship are designed.The mathematical model of rudder angle disturbance and sea wave disturbance is established.The parameter identification of a known hydrodynamic parameter ship HD702 is established based on hydrodynamic parameters.The mathematical model of ship pitch and heave motion can obtain the time course of ship’s pitch and heave by solving the mathematical model.In the still water,heading using CPSO,PSO to identify the HD702 hydrodynamic parameters,the longitudinal motion simulation experiment of the ship with or without noise,and the results of the comparative analysis;the S175 ship calculated by the slicing theory The longitudinal motion hydrodynamic parameters are identified by the improved particle swarm optimization algorithm.The simulation experiments are carried out in the two environments of hydrostatic and tertiary wave disturbances.The motion trend is in good agreement with the theoretical mechanism model.The correctness and rationality of the CPSO identification method can be applied to the ship motion modeling of the navigation simulator,which has certain practical engineering application value.