Parametric Identification for Nonlinear Ship Maneuvering

Abstract

A parametric identification method for the estimation of hydrodynamic derivatives embedded in the nonlinear steering equations for ship maneuvering in calm seas is presented. The models developed for identification involve determination of constant, "low-frequency" hydrodynamic derivatives. The method is robust, noniterative, and computationally light, and it requires no starting estimates. In this method, the time domain operations are converted to linear operations in the frequency domain. The responses of the ship in a few standard maneuvers have been simulated in the numerical examples, and the proposed method is applied to these data in order to estimate the hydrodynamic derivatives for a few "identifiable" combinations.