Parameters Estimation of Nonlinear Manoeuvring Model for Marine Surface Ship Based on PMM Tests

Abstract

A nonlinear manoeuvring mathematical model of marine surface ship model is briefly introduced. In order to obtain the hydrodynamic coefficients, system identification is used to estimate the parameters using Planar Motion Mechanism (PMM) test data. Usually, the obtained parameters using measured data have a large uncertainty due to the ill-conditioned processes of identification. An optimal Truncated Singular Value Decomposition (TSVD) method is exploited to reduce the uncertainty of the estimated parameters. The optimal number of retaining singular values is calculated by using the L-curve, which is a log-log plot of the norm of a regularized solution versus the norm of the corresponding residual norm. It is a graphical tool for displaying the trade-off between the estimated parameters norm and the corresponding residual error norm. The validation process is performed by comparison of the prediction values with the experimental data in the time domain.