Identification of the nonlinear ship model parameters based on the turning test trial and the backstepping procedure

This work presents a novel contribution to solve the problem of identification of ship models parameters using the temporal variation data of the yaw angle achieved from a particular trial test as the turning circle. A relatively complex nonlinear model of Wagner-Smith has been chosen as basis because it represents the ship's dynamics appropriately as proved through the experimental measures obtained in a particular ship. The proposed algorithm of identification of the six ship model parameters is based on the combination of two sub-algorithms: the backstepping procedure and the tuning design method. The simulation results show the suitability of the proposed procedure.