An improved thrust distribution method for ship dynamic positioning system

Abstract

The invention discloses an improved thrust distribution method for a ship power positioning system, and belongs to the technical field of ship power positioning control. The method includes the stepsof, in order to avoid thrust saturation, carrying out normalization processing on the expected thrust of three degrees of freedom, and carrying out amplification processing according to the capacity of a propelling system; using a direct distribution method for carrying out first-time distribution, calculating the rotation angle of a full-rotation propeller after the direct distribution and judging whether the full-rotation propeller enters a rotation forbidding region or not, if yes, replacing with the boundary value adjacent to the rotation angle forbidding area, and reserving the original value if not; updating a propeller position matrix, and carrying out secondary thrust distribution through a pseudo-inverse algorithm. According to the improved thrust distribution method, the problemsof thrust saturation and rotation angle forbidden domain constraint can be well solved. Meanwhile, good real-time performance and stability are achieved, and the positioning capability of a power positioning system can be improved. The problems of forbidden angle, thrust saturation constraint and the like of the propeller are comprehensively considered from the real-time perspective.

Description

technical field [0001] The invention belongs to the technical field of ship dynamic positioning control, and in particular relates to an improved thrust distribution method for a ship dynamic positioning system. Background technique [0002] The dynamic positioning system is one of the necessary support equipment for deep-sea operation equipment (especially deep-sea operation engineering ships that work in harsh sea conditions for a long time). It can safely and effectively help ships complete tasks such as position movement, position maintenance, and target tracking. It plays a very important role in the process of ship operation. The dynamic positioning system is a closed-loop computer control system. Its function is to use the ship's own multiple propellers to keep the ship's position and heading under the specified operating range and environmental conditions. [0003] A dynamic positioning control system usually includes a navigation guidance system, a high-level contr...

AI Technical Summary

Problems solved by technology

Although these algorithms can effectively solve the problem of thrust allocation, there are still some shortcomings. The pseudo-inverse algorithm does not take into account the saturation phenomenon of the propeller thrust and the problem of the prohibition angle of the propeller rotation; although the sequence quadratic programming and intelligent optimization algorithms The forbidden angle and thrust range of the propeller are considered, but the calculation steps are complicated and cannot meet the real-time requirements of the dynamic positioning system

Although the thrust distribution method of ship dynamic positioning system based on the artificial fish swarm algorithm invented by Xia Guoqing et al. has solved the propeller azimuth constraint problem and improved the optimization speed at the same time, because the intelligent optimization algorithm is aimed at different When distributing the thrust command, the number of iterations and calculation time will be very different, so it cannot meet the real-time and stability requirements of the dynamic positioning system.

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