Multivariable Identification of Ship Steering and Roll Motions

This paper addresses identification of a multivariable model describing the rudder induced surge-sway-yaw-roll dynamics of a fast container ship. The identification problem is formulated and is solved numerically by using a random search minimization method. Such method, which has to carry out the estimation of a large number of unknown parameters, is based on a suitable implementation of Simulated Annealing. Application of the algorithm to a set of simulated data has proved to be quite successful. The results show that the proposed identification method is a very efficient and easy-to-use tool for determination of ship hydrodynamic derivatives on the basis of full scale sea trials or from towing tank tests conducted on scale models.