Dynamic positioning model test control method and system based on wind flow feedforward

A technology of dynamic positioning and control method, applied in ship parts, ships, transportation and packaging, etc., can solve the problems of difficult data and information, small integral coefficient value, and the system cannot meet the required positioning accuracy, and achieves high reference value, The effect of improving positioning accuracy

Pending Publication Date: 2020-08-04
SHANGHAI JIAO TONG UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The existing dynamic positioning method of the marine structure model adopts pure feedback control, and the force feedback must be offset first. Although there is an integral link, in order to ensure the stability of the system, the value of the integral coefficient is usually very small
However, in actual control

Method used

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  • Dynamic positioning model test control method and system based on wind flow feedforward
  • Dynamic positioning model test control method and system based on wind flow feedforward
  • Dynamic positioning model test control method and system based on wind flow feedforward

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Embodiment 1

[0019] This embodiment, as a comparative example, relates to the prior art. Assuming that the ship is positioned at the origin, for the traditional control method, the position of the ship at this time is measured by the position measurement system, and the position information is sent to the filter and estimated by the filter. This information is further sent to the central PID controller to calculate the required control force τ, and finally through the thrust distribution module, the thrust is distributed to each thruster of the dynamic positioning ship. control can be expressed as

[0020] τ=k p *x+k d *v+k i *∫x dt

[0021] This is a pure feedback control method, which must have an offset before force feedback. Although there is an integral link, in order to ensure the stability of the system, the value of the integral coefficient is usually very small. In actual control, it is easy to be disturbed by the outside to produce a large offset, and it oscillates back and f...

Embodiment 2

[0022] Embodiment two: Embodiment two is the embodiment of the technical solution of the present invention.

[0023] For the control method of the present invention, we measure and obtain the corresponding wind speed and flow speed through an anemometer and a current meter installed near the center of gravity of the ship;

[0024] According to the above-water and underwater projected area of ​​the ship under the heading angle, the wind force and current force suffered by the ship at this time are estimated, and they are added to the control force τ in advance:

[0025] τ=k p *x+k d *v+k i *∫x dt+F 风前馈 +F 流前馈

[0026]

[0027]

[0028] In the formula, ρ is the density of gas and water, and S is the projected area above and below the waterline respectively, which can be determined according to the heading angle, which is a term in the field of ships and represents the direction of wind, wave and current, such as the heading angle 180 degrees means that it is against ...

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Abstract

The invention relates to a dynamic positioning model test control method based on wind flow feedforward. The position of a ship is measured by a position measuring system; the position information issent to a filter, the filter estimates a low-frequency position x and a low-frequency speed v of the ship, the information is further sent to a central PID controller, and the PID controller calculates the required control force tau, estimates the wind power and the flow force borne by the ship at the moment according to the overwater and underwater projection areas of the ship at the heading angle, and adds the wind power and the flow force into the control force tau in advance: tau = kp * x + kd * v + ki * summing xdt + F wind feedforward + F flow feedforward. The ship can generate approximate thrust to resist external environment loads without deviation in advance due to the fact that feed-forward force is added, and thus high-precision positioning of the ship can be guaranteed. The airflow feedforward mode is adopted so that the positioning precision of the dynamic positioning model test is remarkably improved, and measured data can provide important reference for the design of anactual dynamic positioning system.

Description

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Claims

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Application Information

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Owner SHANGHAI JIAO TONG UNIV
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