船の低速操縦運動の簡易数学モデル

抄録

　The aim of this study is to develop a simplified mathematical model for low-speed manoeuvring motion, which involves significant lateral and rotational motion compared to forward motion, making low-speed manoeuvring critical. To simulate the manoeuvring, it is necessary to model the hydrodynamic forces on a hull, the propeller forces and the rudder forces. Hydrodynamic forces on a hull are highly non-linear and complex, requiring detailed modelling. In addition, various propeller and rudder operations during port manoeuvres require the models to be extended to four quadrants. This study employs the following methods to create a simplified model: a polynomial model using cross-flow drag terms to simplify the non-linear hydrodynamic forces, extending the propeller forces to four quadrants by modifying the thrust coefficient in the first quadrant, and extending the rudder forces based on the slip ratio. Finally, the validity of the model is validated by comparison with free running test results.