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http://dx.doi.org/10.5394/KINPR.2020.44.3.145

A Study on the Estimation of Roll Motion in Large Scale LNG Ships  

Song, Jaeyoung (Graduate School, Korea Maritime & Ocean University)
Lee, Chun-Ki (Division of Navigation Science, Korea Maritime & Ocean University)
Yim, Jeong-Bin (Division of Navigation Science, Korea Maritime & Ocean University)
Publication Information
Journal of Navigation and Port Research / v.44, no.3, 2020 , pp. 145-150 More about this Journal
Abstract
The ship motion of large LNG ships affects ships' safety. The purpose of this study was to estimate the transfer function of roll motion among the hull motion of 153,000 m3 class LNG vessels. The ship motion transfer function was modeled using a Linear Time-Invarient system with single input, single output, and transfer function. The transfer function of the ship motion was estimated by the system identification method using single ocean wave as input of the model, and using the roll motion of the LNG ship obtained through ANSYS as the output of the model. The usefulness of the experimental results was evaluated using the precision and estimation rate of the model for cases wherein the different transfer function dimensions. Results of the experiment showed a precision at 99% and 98%, with estimation rate at 78% and 50%. From these results, we found the proposed method of estimating the transfer function of ship motion in this study reasonable. In the future, data of ship motion in actual sea conditions will be acquired and it will be applied to make the construction of models with multiple inputs and multiple outputs for practical use.
Keywords
Ship's Safety; Ship Motion; Transfer Function; System Identification; Estimation Model;
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