A Method for Identification of Hydrodynamic Coefficients of Dynamically Positioned Vessels

Abstract

The invention relates to the ship dynamic positioning field, in particular to a method for identifying hydrodynamic coefficients of dynamic positioning ships based on the modeling of dynamic positioning ships by means of an adaptive genetic algorithm of a least square method. The method comprises the steps of determining a ship hydrodynamic coefficient; obtaining a longitudinal velocity u, a transverse velocity v and a rotation rate datum r of the sailing of an actual ship; obtaining a longitudinal velocity us, a transverse velocity vs and a rotation rate datum rs of a ship model; determining a target function J; determining a fitness function F; encoding the ship hydrodynamic coefficient; performing selective genetic operation on a population; performing crossover mutation genetic operation on the population, converting a binary code into a hydrodynamic coefficient estimation value; and setting maximum evolution algebra and performing multi-generation inheritance calculation. According to the method for identifying hydrodynamic coefficients of dynamic positioning ships, only the actual ship sailing velocity is needed to be recorded, and the model experiment is not needed, so that the design cost of a dynamic positioning system is saved.

Description

technical field [0001] The invention relates to the field of ship dynamic positioning, in particular to a method for modeling a dynamic positioning ship and identifying the hydrodynamic coefficient of the dynamic positioning ship using an adaptive genetic algorithm based on the least square method. Background technique [0002] A dynamic positioning ship is a ship that can automatically maintain its position and course (fixed position or predetermined track) only by its own propulsion system. It has been widely used in many fields of marine resource development. Usually, modeling a dynamically positioned ship requires knowing the hydrodynamic coefficient of the ship. The hydrodynamic coefficient of the ship is the value of the partial derivative of the hydrodynamic force on the ship's motion parameters at the expansion point. The hydrodynamic coefficient is the basis for establishing the ship's motion equation, and the acquisition of the hydrodynamic coefficient plays a vita...

AI Technical Summary

Problems solved by technology

However, it is very difficult to test all the ships to be studied, and the traditional optimization method tends to make the calculation results tend to the local optimal solution

With the advancement of science and technology, in recent years, adaptive genetic algorithm as an intelligent algorithm has been widely used in the research of parameter identification, but it has not been used in the identification of hydrodynamic coefficients of dynamic positioning ships, and there are relatively few related literatures, involving intelligent algorithms There are relatively few domestic and foreign studies on the identification of hydrodynamic coefficients for ships, and even fewer studies on the identification of hydrodynamic coefficients for dynamic positioning ships

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