A Thrust Distribution Method for Reducing Wear of Thrusters in Dynamically Positioned Ships

Abstract

The invention discloses a thrust distribution method for reducing the wear and tear of a propeller of a dynamic positioning ship. First, a mathematical model of thrust distribution is established according to the propeller layout of a dynamic positioning ship, and then the mathematical model of thrust distribution is calculated by using a quadratic programming algorithm. Carry out the solution to obtain the thrust magnitude and direction of each thruster, then calculate the difference between the angles of each thruster in the last allocation cycle and the angle of the current allocation thruster, compare the difference with the specified threshold, if the difference is greater than the threshold, then Output the current thrust magnitude and direction, if the difference is less than the specified threshold, keep the azimuth angle of the propeller unchanged, re-establish the mathematical model of thrust distribution for secondary thrust distribution, and recalculate the thrust magnitude and direction of each propeller. The adoption of the thrust distribution method proposed by the present invention can effectively avoid the frequent rotation of the azimuth propeller, thereby reducing wear of the propeller and improving the service life of the propeller.

Description

technical field [0001] The invention belongs to a dynamic positioning system of a ship, in particular to a thrust distribution method for reducing wear of an azimuth thruster in the dynamic positioning system. Background technique [0002] The current dynamic positioning system is widely used in marine engineering ships, and has become an indispensable system for the development and utilization of deep sea resources. Due to the limitation of water depth and ship maneuverability, the traditional anchoring positioning system cannot meet the needs of deep sea positioning operations of ships or platforms. The dynamic positioning system can use the thrust generated by its own propeller to offset the external environmental force, so as to keep the ship or platform on the predetermined position or track, and has the advantages of not being limited by the water depth, high positioning accuracy, and good maneuverability. [0003] Thrust distribution is an important part of the dynam...

AI Technical Summary

Problems solved by technology

[0004] Dynamically positioned ships or platforms are usually equipped with multiple azimuth thrusters. Due to the complex and changeable marine environment, in order to meet the requirements of control force and moment, in the variable angle mode, using the traditional thrust distribution method, the azimuth thrusters need Frequent and rapid angle changes lead to serious wear of the slewing device of the azimuth propeller, reducing the service life of the propeller, which in turn affects the economics of dynamic positioning ships or platform operations

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