Determination of ship maneuvering hydrodynamic coecients using system identi cation technique based on free-running model test


Department of Mechanical Engineering, Sharif University of Technology, Center of Excellence in Hydrodynamics and Dynamics of Marine Vehicles, Tehran, Iran.


In the recent years, di erent mathematical models have been suggested for maneuvering of displacement vessels that are capable of estimation of vessel maneuvers with acceptable precision. These mathematical models are based on determined hydrodynamic coecients and their accuracy depends on the known coecients used to solve the mathematical model. System identi cation methods are developed to calculate these coecients utilizing input and output data obtained from di erent sources. In this research, a 4.36-m model of KRISO Container Ship (KCS) displacement vessel has been manufactured by berglass, and the maneuver turning tests have been carried by selfpropulsion method. A 3DM-GX1 sensor, together with a protractor and Global Positioning System (GPS), has been used to measure the yaw and rudder angle, position, linear accelerations, and angular velocities of the vessel in di erent times. The hydrodynamic coecients in the mathematical model are determined by the Extended Kalman lter method. Then, the mathematical model is solved and di erent maneuvers are simulated by coecients calculated from the experiments. Simulations are validated by model tests. The mathematical model and hydrodynamic coecients presented in this paper can be applied for optimization of ship maneuvering performance and course control purposes