Modeling And Simulation Of Ship Turning Around With Tug Assistance

In recent years, the number of ships is increasing, vessels gradually towards to large, high-speed, and specialized. Since the development of the port waters is limited, the number of ships in port is continuously intensive, at the same time ship handling water becomes relatively shallow and narrow, which causes difficulty and complexity in handling ship. In order to navigate safer and more efficient, tugs assist the ship to maneuver which ensures the safety of the harbor navigation has become an indispensable means, especially in the port for berthing of ships or away from the park need to turn around, ship is saling in slow speed and steerability is very poor, when it is difficult to achieve by themselves, so tugs to assist ship is a important means. The tug assistance of the performance of the ship on the operation is successful or not, which is a concern problem in the field.Tugs to assist the ship to turn around usually occur when vessels from berthing or mooring process, this article has been read and the review the public information based on the theory of Japan MMG modeling, to establish a more accurate, complete tugs to assist the ship equations of motion. Domain model in the constant speed and low speed, large drift angle based on the mathematical model, taking into account the continuity of the movement of ships, using mathematical models to combine two methods, namely, constant velocity field (drift angle less than 20°) used Kijima model, the low field (drift angle more than 30°) used Yoshimura model, drift angle between the two models using the results of interpolation.In order to facilitate better qualitative analysis, the paper considered the wind and current on the interaction between the tug and the ship, using a four-order Runge-Kutta method to calculat equations of motion of the manipulation of the mathematical, and using mathematical tools MATLAB language in the Simulink toolbox to simulate the tugs to assist the ship turning around, respectively simulating tugs in different conditions and in the wind and current tugs to assist ships turning around, and draw up a series of very important theories, which has theoretical significance in handling ship. This research is for navigating cited staff navigating safely with some value and theoretical significance, and provides a theoretical reference for manipulation of the safety assessment of the tug, it also provides a theoretical foundation to navigation simulator research and development.